TECHNOLOGICAL FIELD
[0001] This invention relates generally to the field of horology, and in particular to a
timepiece that has a wheel train driven by a mainspring and by an electric motor.
BACKGROUND
[0002] Generally, a conventional mechanical timepiece has a movement that includes a barrel
which houses a mainspring providing a power source for the mechanical timepiece, a
main (or primary) wheel train driven by the barrel, and a regulating device including
a hairspring balance for controlling rotation of the wheel train. The regulating device
also includes an escapement for maintaining angular oscillations of the hairspring
balance of the regulating device arranged between the main wheel train and the hairspring
balance. The arbors of certain wheels of the main wheel train bear indicator hands.
[0003] In modem watches, the mainspring is coiled around a barrel arbor, and is affixed
to the barrel arbor at its inner end, and to the barrel at its outer end. The mainspring
is wound by turning the arbor, but drives the watch movement by the barrel; this arrangement
allows the mainspring to continue powering the watch while it is being wound.
[0004] Winding the watch turns the arbor, which tightens the mainspring, wrapping it closer
around the arbor. The arbor has a ratchet attached to it, with a click to prevent
the mainspring from turning the arbor backward and unwinding. After winding, the arbor
is stationary and the pull of the mainspring turns the barrel, which has a ring of
gear teeth meshing with the pinion of the center wheel of the wheel train.
[0005] The barrel usually rotates once every 8 hours, so, for example, the common 40 hour
mainspring requires 5 turns to unwind completely.
[0006] Fig. 1 illustrates a relationship between the number of turns
n of an arbor
10 and the torque output
M provided by a mainspring
11 housed in a barrel
13. In the released state (shown by a Roman reference numeral
I), when the mainspring
11 is completely unwound, coils
12 of the mainspring are tight near an inner wall of the barrel
13. A torque provided by the mainspring in this state is zero. This point is indicated
by an alphabetic character
A on a curve of the dependence of a torque
M versus a number of turns
n of the arbor.
[0007] The state shown by a Roman reference numeral
II corresponds to the first turns of the arbor. For standard spring engines, a number
of turns corresponding to transition from the state
I to the state
II can be from 1 to 3, depending on the size of the barrel, the length and thickness
of the mainspring
11. In the state
II, only the first and the last coils of the mainspring are located adjacent to the arbor
and to the barrel, correspondingly, while the remaining coils of the mainspring are
separated uniformly from each other and are retained in the concentric shape. During
transition from the state
I to the state
II, the coils untighten from the barrel and thus create a driving torque. The coils,
which remain tight to the inner wall of the barrel, do not participate in creation
of the driving torque. The transition from the state
I to the state
II is characterized by a non-linear increase of the torque magnitude from the point
A up to the point
B on the curve of the dependence of the torque versus the number of turns of the arbor.
[0008] Further, during winding up the mainspring
11 from the state
II to the state
IV through the transitional state
III, all coils of the mainspring are untightened from the barrel
13, and thus participate in creation of the driving torque. During transition from the
state
II to the state
IV, the winding is characterized by a linear increase of the torque magnitude from the
point
B up to the point C. Depending on the method of fastening of the mainspring to the
inner wall of the barrel, the coils in the transitional state
III can be either concentric or eccentric. In the state
IV, the coils tighten together and are wrapped around the arbor.
[0009] Further winding up the mainspring
11 to the fully wound state
V increases the friction between the coils that results in a sharp non-linear increase
of the torque magnitude from point
C up to point
D on the curve of the dependence of the torque versus the number of turns of the arbor.
A number of turns corresponding to transition from the state
IV to the state
V can be from about 1 to 2.5,
[0010] During unwinding from the state
V to the state
IV, a very sharp reduction of the torque magnitude from the point
D down to the point E is monitored on the curve of the dependence of the torque versus
the number of turns of the arbor. The coils wrapped around the arbor
10 become less tight. Further, during unwinding from the state
IV to the state
II through the state
III, the coils are unwrapped from the arbor, and the torque output follows a linear dependence
on the curve of the dependence of the torque versus the number of turns from the point
E down to the point
G through point
F. The section
GE on the curve passes below the section
BC, owing to the hysteresis.
[0011] At the last stage of unwinding from the state
II to the state
I, the coils tightens near the inner wall of the arbor
10, and the torque output of the mainspring
11 diminishes from the point
G down to down to zero at the point
A.
[0012] It should be noted that during unwinding in a conventional mechanical timepiece only
a liner part of the dependence of the torque versus the number of turns (i.e., section
GE) is used. In particular, the large torque output that is provided by the mainspring
11 during unwinding from the state
V to the state
IV is not used, because such a sudden large torque can cause damage to the regulating
device controlling rotation of the main wheel train and to the escapement. Likewise,
when the torque output provided by the mainspring during unwinding becomes smaller
than the magnitude corresponding to the point
G, the indicator hands gradually slow down and the timepiece stops operating, because,
the torque associated with friction in the wheel train exceeds the torque output provided
by the mainspring
11.
[0013] In order to maintain a mainspring within a set torque range that usually corresponds
to the linear operating regime, timepieces are usually provided with a winding-up
stop mechanism and an unwinding stop mechanism that prevent winding and/or unwinding
of the mainspring beyond a certain maximum number of turns during winding or minimum
number of turns during unwinding.
[0014] For example,
U.S. Pat. No 6,422,739 to Hara et al. describes a timepiece that drives a primary (main) wheel train by mechanical energy
of a mainspring. The timepiece includes a winding-up portion that accumulates energy
in the mainspring; an addition-and-subtraction wheel train driven by addition and
subtraction of accumulated energy corresponding to an amount by which the mainspring
is wound up and unwound, respectively. An addition-and-subtraction wheel is disposed
in the addition-and-subtraction wheel train can rotate in correspondence with an amount
by which the mainspring is wound up and unwound. The winding-up portion includes a
lock mechanism actuated in response to the rotation of the addition-and-subtraction
wheel to limit winding up and unwinding of the mainspring to a selected range of windings,
and to thereby prevent transmission of torque having a value outside a set range from
the mainspring to the primary wheel train.
[0015] As can be seen in the graph shown in
Fig. 1, the torque provided by a mainspring in a conventional mechanical timepiece is not
constant, but diminishes as the mainspring unwinds. In turn, as mainspring unwinds
and the torque decreases on the linear section
GE from the maximal torque
Mmax to the minimal torque
Mmin, a swing angle of the balance wheel also decreases and precision of the timepiece
changes. In particular, the timepiece can be precise at a certain optimal magnitude
Mopt, while advance or delay when the torque is greater or lower than the optimal magnitude
Mopt, correspondingly.
[0016] Several approaches are known in the art for increasing operation time of a timepiece
and improving timepiece precision.The operation time of a timepiece can, for example,
be extended by increasing potential energy stored in the mainspring by using a mainspring
with a greater torque. Moreover, the operation time can be extended by utilizing dedicated
mechanisms reducing the torque required to drive the main wheel train. Likewise, electro-magnetic
motors can be used for providing additional power to the mainspring. In turn, the
timepiece accuracy can be improved by utilizing various stabilization mechanisms that
stabilize the torque on the barrel and/or the swing angle of the balance.
[0017] For example,
GB2349240 to Parker et al. describes a power source for automatically winding up a mechanical clock. The power
source includes an electric motor, control means for the motor and means adapted to
connect the output from the motor to a component of the power drive of the clock.
In particular, the output shaft of the electric motor is connected by a chain and
sprocket drive to a winding drum (i.e., barrel which houses a mainspring) of the clock.
The control means are configured for sensing the torque at the output from the motor
and controlling the supply of current to the motor in accordance with the torque sensed.
When a minimum value of torque is detected the control means permits current to be
supplied to the motor so that power can be transmitted to the driving drum. When adequate
power has been supplied, further rotation of the winding drum is resisted by a ratchet
mechanism. Consequently, if the load on the motor shaft increases beyond a predetermined
maximum torque, the control means discontinues the current supply until the minimum
value of torque is detected again.
[0018] U.S. Pat. No. 7,906,938 to Yang describes a timing device that utilizes hybrid power to intermittently drive a movement
of the timing device. To achieve this purpose, electrical power from a power supply
is timely delivered to an electro-magnetic driving unit including an electric motor
that provides torque to drive the mainspring barrel through an automatic control unit
manipulated by a mechanical energy storage status detection unit to produce mechanical
energy.
[0019] It should be noted that winding a mainspring by an electric motor, as described in
GB2349240 and
U.S. Pat. No. 7,906,938, can require powerful electric motors and corresponding batteries for driving such
electric motors. This requirement can result in serious difficulties in placing such
powerful batteries within a limited space inside of wrist watches.
[0020] Another way to increase operation time of a timepiece can be based on the stabilization
of the torque on the barrel by means of redistribution of the torque provided by the
mainspring during unwinding. In operation, the maximal torque magnitude
Mmax at point
E in the graph in
Fig. 1 can exceed the optimal magnitude
Mopt at the point F by 15-20%. This torque excess can increase the load on the main wheel
train, and if this large torque of the mainspring is not used, the energy corresponding
to this torque excess is wasted. On the other hand, as the torque decreases below
the optimal magnitude
Mopt, the timepiece precision gradually drops.
[0021] U.S. Pat. No. 7,832,924 to Nagasaka describes a timepiece having a mechanism that enables accumulation of the energy corresponding
to torque excess, and supplying this energy for driving the wheel train when torque
magnitude is low. The timepiece includes a mainspring, an output wheel that is rotated
by torque output from the mainspring, a lever that pivots synchronously to the output
wheel, and a pressure member, such as a spring that pushes the lever. The pressure
member pushes the lever so that the output torque of the output wheel increases as
the mainspring unwinds.
[0022] The total torque that drives the timepiece is the torque combining the torque output
from the mainspring and the torque applied to the output wheel by the pressure from
the lever. Because the torque applied to the output wheel increases as the mainspring
unwinds, this additional torque assists the decreasing torque from the mainspring
as the mainspring unwinds. The problem of reduced precision resulting from the large
difference between the torque output of the mainspring when the mainspring is fully
wound and the torque output when the mainspring is unwound can therefore be solved,
and stable timekeeping can be assured. Furthermore, because the torque applied to
the output wheel increases as the mainspring unwinds, the timepiece can be driven
beyond the point where the timepiece stops when the mainspring unwinds in a timepiece
without such a mechanism, and the timepiece can be driven for a longer continuous
operating time.
[0023] U.S. Pat. No. 7,780,342 to Takahashi et al. describes a timepiece having a mechanism that enables increasing the duration time
of the mainspring by means of redistribution of the torque provided by the mainspring
during unwinding on the linear part of the dependence of the torque versus the number
of turns of the arbor of the mainspring. The timepiece includes a spring device having
an inside-end wheel, an outside-end wheel and a torque return unit. The inside-end
wheel moves in conjunction with the inside end of the mainspring. The outside-end
wheel moves in conjunction with the outside end of the mainspring. The torque return
unit transfers part of the output torque of the mainspring from one to the other of
the inside-end wheel and outside-end wheel.
[0024] The inside-end wheel and the outside-end wheel are connected through the torque return
unit only when the mainspring is wound greater than a reference number of winds so
that the mainspring is wound by part of the output torque of the mainspring communicated
through the drive wheel train being returned through the torque return unit to the
mainspring. When the mainspring unwinds to a number of winds less than the reference
number of winds, the connection between the inside-end wheel and outside-end wheel
is disengaged by a torque transfer clutch unit, and all output torque from the mainspring
is applied to drive the main wheel train.
[0025] As explained above, during unwinding of the mainspring, the mainspring torque and
the swing angle of the balance is reduced and, accordingly, precision of the timepiece
changes. European Patent Application No.
1172713 to Sasaki et al. describes a mechanical timepiece that comprises a detecting unit configured for detecting
a swing angle of the hairspring balance by detecting an operational state of the balance
by using light, and a braking unit configured for controlling the swing angle for
adjusting the timepiece precision. The braking unit is adapted such that when the
swing angle of the hairspring balance detected by the detecting unit is equal to or
larger than a predetermined angle, a force of restraining rotation of the hairspring
balance is exerted to the hairspring balance.
[0026] The braking unit includes a balance magnet mounted on the hairspring balance and
coils arranged to be capable of braking motion of the balance magnet mounted on the
hairspring balance. The braking unit also includes a balance rotation detecting circuit
configured to control light emitted by the light emitting portion and a balance rotation
controlling circuit constituted to measure operation of the balance arm portion and
calculate a swing angle of the balance with hairspring. The balance rotation controlling
circuit of the mechanical timepiece is configured to disconnect the coils from electrical
power when the swing angle of the balance with hairspring is less than a certain threshold
magnitude, and to feed the coils with electrical power when the swing angle of the
hairspring balance is equal to or larger than the threshold magnitude.
GENERAL DESCRIPTION
[0027] Thus, there is still a need in the art for, and it would be useful to have, a novel
a timepiece that can be driven for a longer continuous operating time than a conventional
mechanical timepiece.
[0028] It would also be beneficial if a timepiece would have an enhanced precision.
[0029] The present invention is defined by appended claim 1. It partially eliminates the
deficiencies of the prior art horology devices, and provides a novel timepiece. According
to an embodiment of the present invention, the timepiece includes a mechanical power
system having a mainspring associated with a ratchet and housed in a barrel that is
powered by the mechanical energy provided by the mainspring. The timepiece also includes
a main (primary) wheel train engaged with the barrel. The main wheel train includes
an assembly of wheels meshed to each other for transmitting a torque output of the
mainspring for driving time indicating hands. The timepiece also includes a timepiece
regulating device having a balance engaged with the main wheel train and an escapement
adapted for maintaining angular oscillations of the balance. The timepiece also includes
a manual winding and hand adjustment mechanism coupled to the ratchet and to the time
indicating hands.
[0030] According to an embodiment of the present invention, the timepiece further includes
an electric motor engaged with a predetermined wheel of the main wheel train through
an electric motor transmission mechanism, so as to provide an additional controllable
torque output to main wheel train for driving said time indicating hands. Thus, a
total torque that drives the timepiece includes the torque provided by the mainspring
and the additional controllable torque provided by the electric motor.
[0031] According to an embodiment of the present invention, the predetermined wheel of the
main wheel train that is engaged with said electric motor transmission mechanism is
the third wheel when the counting starts from the barrel.
[0032] According to an embodiment of the present invention, the timepiece further includes
a torque regulation mechanism coupled to the mechanical power system, and configured
to control operation of the mainspring and the ratchet during winding and unwinding
the mainspring.
[0033] According to an embodiment of the present invention, the torque regulation mechanism
includes a ratchet wheel train coupled to the ratchet, and a ratchet lock mechanism
configured for locking said ratchet wheel train for stopping rotation of the ratchet.
[0034] According to an embodiment of the present invention, the torque regulation mechanism
also includes a barrel wheel train coupled to the barrel, and a barrel lock mechanism
configured for stopping or allowing rotation of the barrel. The torque regulation
mechanism also includes a first cam wheel coupled to the ratchet lock mechanism and
to the barrel lock mechanism, and configured for activating the ratchet lock mechanism
and the barrel lock mechanism to stop or enable rotation of the ratchet and the barrel
during winding the mainspring, correspondingly.
[0035] According to an embodiment of the present invention, the torque regulation mechanism
further includes a click lifting mechanism configured for releasing the ratchet to
enable rotation of the ratchet in a direction that is reverse to the rotation of the
ratchet during winding the mainspring. The torque regulation mechanism also includes
a second cam wheel coupled to the click lifting mechanism, and configured for activating
the click lifting mechanism. The second cam wheel can have an arbor common with the
arbor of the first cam wheel and be mounted on and coupled to the first cam wheel.
[0036] According to an embodiment of the present invention, the timepiece further includes
a mainspring winding level indicator. For example, the mainspring winding level indicator
can include a needle affixed to the arbor of the first and second cam wheels, and
a sub-dial marked with indicia.
[0037] According to an embodiment of the present invention, the timepiece further includes
an electric battery for providing electrical power to the electric motor, and an electric
motor controller coupled to the electric battery and to the electric motor. The electric
motor controller is configured to drive the electric motor by controllably supplying
electrical power from the electric battery thereto.
[0038] According to an embodiment of the present invention, the timepiece further includes
an electric generator configured to generate an electrical energy for charging the
electric battery, and a generator transmission mechanism.
[0039] According to an embodiment of the present invention, the generator transmission mechanism
includes a ratchet torque transmission train coupled to the ratchet, and configured
for transmitting a torque from the ratchet to the electric generator for driving thereof
during rotation of the ratchet.
[0040] According to an embodiment of the present invention, the timepiece further includes
an automatic winding mechanism coupled to the generator transmission mechanism, and
configured to rotate the ratchet for winding the mainspring and to drive the electric
generator for charging the electric battery.
[0041] According to an embodiment of the present invention, the timepiece regulating device
includes a detecting unit and a processing unit electrically coupled to detecting
unit. The detecting unit is configured for measuring rotational operation the balance
for determining an oscillation period of the balance. The processing unit is configured
for processing the data measured by the detecting unit, and when the measured data
deviate from predetermined magnitudes, generating control signals and relaying them
to the electric motor controller for driving the electric motor to provide the additional
controllable torque for driving the main wheel train.
[0042] According to an embodiment of the present invention, the detecting unit includes
an electromagnetic transmitter arranged at on one side of the balance and configured
for irradiating an arm portion of the balance, and an electromagnetic receiver arranged
at the opposite side of the balance and positioned in an optical path so that a field
of view of the electromagnetic receiver ensures the capture of a part of the radiation
which is transmitted by the electromagnetic transmitter and irradiated the arm portion
of the balance.
[0043] According to an embodiment of the present invention, the processing unit includes
a memory unit and a processor. The memory unit can, for example, store a relationship
between an oscillation period of the balance and a torque driving the main train wheel.
The memory unit can also store an optimal magnitude of the operating torque driving
the main train wheel at which operation of the timepiece is precise. The processor
can, for example, be configured for analyzing the data measured by the detecting unit,
calculating the current operating torque and its deviation from the optimal magnitude,
and for generating the control signals to the electric motor controller to drive electric
motor, if the current operating torque deviates from the optimal torque magnitude.
[0044] There has thus been outlined, rather broadly, the more important features of the
invention in order that the detailed description thereof that follows hereinafter
may be better understood. Additional details and advantages of the invention will
be set forth in the detailed description, and in part will be appreciated from the
description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] In order to better understand the subject matter that is disclosed herein and to
exemplify how it may be carried out in practice, embodiments will now be described,
by way of non-limiting example only, with reference to the accompanying drawings,
in which:
Fig. 1 illustrates schematically a relationship between the number of turns of an arbor
and the torque output provided by a mainspring;
Fig. 2 illustrates a schematic block diagram of a timepiece, according to a one embodiment
of the invention;
Fig. 3 illustrates a schematic plan view of a front side of the timepiece shown in Fig. 2, according to an embodiment of the present invention;
Fig. 4 illustrates schematic a schematic plan view of a first cam of the torque regulation
mechanism of the timepiece, according to an embodiment of the present invention;
Figs. 5A and 5B illustrate a schematic view of the torque regulation mechanism in locked and unlocked
states, correspondingly, according to an embodiment of the present application;
Fig. 6 illustrates schematic a schematic plan view of a second cam of the torque regulation
mechanism of the timepiece, according to an embodiment of the present invention;
Fig. 7 illustrates schematic spatial relation in the torque regulation mechanism between
the first cam wheel, the second cam wheel, ratchet lock lever, the barrel lock lever
and the pusher lever, according to an embodiment of the present invention;
Fig. 8 illustrates a schematic perspective view of the generator transmission mechanism
for driving the generator, according to an embodiment of the present invention;
Fig. 9 illustrates a perspective top view of the unidirectional coupling-clutch device of
the generator transmission mechanism, according to an embodiment of the present invention;
and
Fig. 10 illustrates a schematic perspective view of the electric motor transmission mechanism
and the regulation device, according to a one embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0046] The principles of the timepiece according to the present invention may be better
understood with reference to the drawings and the accompanying description, wherein
like reference numerals have been used throughout to designate identical elements.
It is to be understood that these drawings, which are not necessarily to scale, are
given for illustrative purposes only and are not intended to limit the scope of the
invention. For example, the dimensions of some of the elements in the figures may
be exaggerated relative to other elements to help improve understanding of various
embodiments. In addition, the description and drawings do not necessarily require
the order illustrated. It will be further appreciated that certain actions and/or
steps may be described or depicted in a particular order of occurrence while those
skilled in the art will understand that such specificity with respect to sequence
is not actually required.
[0047] It should be noted that the blocks as well other elements in these figures are intended
as functional entities only, such that the functional relationships between the entities
are shown, rather than any physical connections and/or physical relationships. Those
versed in the art should appreciate that many of the examples provided have suitable
alternatives which may be utilized.
[0048] Referring to
Fig. 2, a schematic block diagram of a timepiece
20 is illustrated, according to a one embodiment of the present invention. The timepiece
20 of the present invention involves integration of mechanical and electric mechanisms
and devices which are indicated by block-modules in
Fig. 2, and is not limited to a specific implementation of its components.
[0049] As shown in
Fig. 2, the timepiece
20 includes a mechanical power system (generally indicated by a reference numeral
200 having a mainspring
201 housed in a barrel
202 that is powered by the mechanical energy provided by the mainspring
201. The timepiece
20 also includes a main (primary) wheel train
203 engaged with the barrel
202. The timepiece
20 also includes a timepiece regulating device
204 including a hairspring balance
205 and engaged with the main wheel train
203. The timepiece
20 also includes an escapement
206 adapted for maintaining angular oscillations of a balance wheel (not shown) of the
hairspring balance.
[0050] The mainspring
201 may be wound by one or more known winding mechanisms. Thus, the timepiece
20 includes a manual winding and hand adjustment mechanism (generally indicated by a
reference numeral
207). When desired, the timepiece
20 can also include an automatic winding mechanism
208.
[0051] The main wheel train
203 includes an assembly of wheels (not shown) meshed to each other in the usual manner
for transmitting a torque output of the mainspring
201 through the wheels with the appropriate multiplying ratios for driving time indicating
hands
209 as the mainspring
201 unwinds.
[0052] According to an embodiment of the present invention, the timepiece
20 also includes an electric motor
210 engaged with the main wheel train
203 through an electric motor transmission mechanism
211, so as to provide an additional controllable torque output for driving time indicating
hands
209. The additional controllable torque output that is provided by the electric motor
210 is applied to a predetermined wheel of the main wheel train
203 that is dedicated for this purpose, as will be described hereinbelow in detail.
[0053] Thus, the total torque that drives the timepiece
20 is the torque output combining the torque from the mainspring
201 and the torque applied to the main wheel train
203 by the electric motor
210. Since the torque output from the mainspring
201 decreases as the mainspring unwinds, this additional torque provided by the electric
motor
210 can,
inter alia, drive the main wheel train
203 when the torque associated with the friction in the wheel train exceeds the torque
provided by the mainspring (i.e., section
AG in
Fig. 1). As described above, conventional timepieces cannot normally operate when the
torque decreases below the magnitude corresponding to point
G in the graph in
Fig. 1, because below the magnitude corresponding to point
G the hands of a conventional timepiece gradually slow down, and finally the timepiece
stops operating. Thus, when the mainspring
201 is unwound beyond point
G, the timepiece
20 can be driven by the electric motor
210; thereby the timepiece
20 can be driven for a longer continuous operating time than a conventional timepiece.
[0054] Moreover, as will be described hereinbelow in detail, during unwinding of the mainspring,
the electric motor
210 can assists to drive the main wheel train
203 also at the linear torque regime between the states
II and
IV in
Fig. 1, so as to maintain the total torque that drives the timepiece at a predetermined magnitude
close to a certain optimal magnitude
Mopt. The problem of reduced precision resulting from the large difference between the
torque output of the mainspring when the mainspring is wound and the torque output
when the mainspring is unwound is therefore can be solved, and stable timekeeping
can be assured.
[0055] As described above, the non-linear torque region between the states
IV and
V in
Fig. 1 is usually not used in conventional mechanical timepieces, because a large torque
output in this region can cause damage to the regulating device
204 controlling rotation of the main wheel train
203 and to the escapement
206 during unwinding. On the other hand, according to an embodiment of the present invention,
winding of the mainspring
201 is not ceased at point C at the end of the linear torque regime between states
II and
IV in
Fig. 1, as it is carried out in conventional timepieces, but rather continues further within
the non linear torque regime beyond state
IV towards fully wound state
V. For example, the winding of the mainspring
201 can be continued up to 90% of the non-linear torque region between states
IV and
V in
Fig. 1 or even can be continued further.
[0056] In order to control operation of the mainspring
201 during winding and unwinding, the timepiece
20 includes a torque regulation mechanism
218 that is engaged with a ratchet (not shown) of the barrel
202 and with a barrel gear (not shown) formed on the outside circumference of the barrel
202.
[0057] According to one embodiment of the present invention, the torque regulation mechanism
218 stops rotating the barrel
202 during winding at the end of the linear torque region (point
C in the graph in
Fig. 1). This feature prevents damage to the regulating device
204 that controls rotation of the main wheel train
203 and to the escapement
206 during unwinding caused by a large torque output in the non-linear region. According
to this embodiment, winding of the mainspring
201 can be ceased together with the stopping of the barrel, as it is usually carried
out in conventional timepieces.
[0058] According to another embodiment of the present invention, the winding of the mainspring
201 is not ceased together with the stopping of the barrel, but is rather continued further
until the mainspring
201 is wound up to a predetermined wound state. For example, the mainspring
201 can be wound up to 90% of the non-linear torque region or even further until the
mainspring
201 reaches the fully wound state. Thus, according to an embodiment of the present invention,
the torque regulation mechanism
218 is also configured for blocking rotation of a ratchet (not shown) associated with
the mainspring
201 as the mainspring
201 is wound to a predetermined or fully wound state.
[0059] According to an embodiment, the present application utilizes the non-linear torque
region between states
IV and
V in
Fig. 1 in order to charge an electric battery
212 that provides electrical power to the electric motor
210. The electric battery
212 is electrically coupled to the electric motor
210 through an electric motor controller
213. The electric motor controller
213 is configured to drive the electric motor
210 by controllably supplying electrical power thereto. Examples of the electric motor
210 suitable for the present invention include, but are not limited to, a bi-directional
stepper motor, an AC synchronous or AC asynchronous motor, a DC synchronous or DC
asynchronous motor, etc.
[0060] In operation, the electric motor
210 can be powered by a voltage generated by the electric motor controller
213. For example, a stepper motor can be powered by a train of voltage pulses so as to
provide a precisely defined increment in position of a motor shaft (not shown) and
to turn the shaft by a fixed desired angle. Suitable motors for timepieces and electric
motor controllers for driving such motors are widely commercially available. The construction
of such motors and electric motor controllers to functionally operate in the desired
manner is well within the understanding of those versed in the art.
[0061] According to an embodiment of the present invention, the timepiece regulating device
204 of the timepiece
20 includes a balance oscillation controller
214 associated with the hairspring balance
205, and electrically coupled to the electric motor controller
213. The balance oscillation controller
214 is configured for controlling accuracy of the timepiece
20. In operation, the balance oscillation controller
214 can detect oscillation parameters of a balance wheel (not shown) of the balance
205, e.g., an oscillation period of the balance
205, an amplitude of a swing angle, etc., and generates a deviation indication signals,
if the measured parameters of the balance
205 deviate from predetermined parameters of the balance
205 which correspond to a precise operation of the timepiece. For example, when during
unwinding the mainspring reaches a state corresponding to point
G in the graph in
Fig. 1 and leaves the linear operation regime, the balance oscillation controller
214 can generate a deviation indication signal indicating decrease of the oscillation
period of the balance
205 and/or changes of the swing angle, and relays this signal to the electric motor controller
213. Responsive to this signal, the electric motor controller
213 can generate a train of driving pulses for activating and driving the electric motor
210 as long as required.
[0062] Likewise, according to an embodiment of the present invention, the balance oscillation
controller
214 can be configured for controlling accuracy of the timepiece
20 at the linear torque regime between the states
II and
IV in
Fig. 1. In particular, the balance oscillation controller
214 can be configured for determining the current operating torque and generating a deviation
indication signal, if the measured operating torque deviates from the optimal torque
magnitude
Mopt in
Fig. 1 that correspond to precise operation of the timepiece. This feature enables maintaining
the total torque that drives the timepiece at a predetermined magnitude close to the
optimal magnitude
Mopt.
[0063] According to an embodiment of the present invention, the timepiece
20 includes an electric generator
215 configured to generate an electrical energy for charging the electric battery
212. The electric battery
212 is electrically coupled to the electric generator
215 through a battery charge controller
216 configured to control the charging process. The control of the charging process can
be carried out by maintaining a required charging electric current for providing an
output voltage by the battery
212 within desired magnitudes.
[0064] The electric generator
215 can be driven by one or several mechanisms.
[0065] Thus, according to an embodiment of the present invention, when the user of the timepiece
winds the timepiece up, the electric generator
215 can be driven by the manual winding and hand adjustment mechanism
207 that rotates a ratchet (not shown) of the barrel
202 that is associated with an arbor (not shown) of the mainspring
201 of the mechanical power system
200. The electric generator
215 can be mechanically coupled to the mechanical power system
200 through a generator transmission mechanism
217 engaged with the ratchet.
[0066] According to another embodiment of the present invention, the electric generator
215 can also be driven by the mechanical power system
200. According to this embodiment, the generator transmission mechanism
217 can be engaged with the ratchet associated with the mainspring
201. Thus, the rotation of the ratchet during winding can drive the electric generator
215 when the mainspring is wound from completely unwound state (
I in
Fig. 1) to the state
(V in
Fig. 1) in which the mainspring is fully wound.
[0067] Moreover, the electric generator
215 can also be driven during unwinding the mainspring from the state
(V in
Fig. 1) in which the mainspring in the fully wound state (that is selected near the end of
the non-linear torque region corresponding to the point
D in the graph in
Fig. 1) to a predetermined wound state, for example, to the state
(IV in
Fig. 1) that corresponds to the beginning of the linear torque region (point
E in the graph in
Fig. 1). This can be achieved by enabling a counterclockwise rotation of the ratchet (that
is reverse to the clockwise rotation during winding) only when the mainspring
21 unwinds in the non-linear torque regime, and blocking the reverse rotation of the
ratchet at the moment when the mainspring unwinds to the beginning of the linear torque
region (point
E in the graph in
Fig. 1). This function (as will be described hereinbelow in detail) is controlled by the torque
regulation mechanism
218 that is also configured for engagement of the ratchet with the generator transmission
mechanism
217 for driving the electric generator
210 only during unwinding the mainspring in the non-linear torque regime.
[0068] According to a further embodiment of the present invention, when the timepiece is
moved, the electric generator
215 can also be driven by the automatic winding mechanism
208. The automatic winding mechanism
208 can be coupled to the electric generator
215 through a special part of the generator transmission mechanism
217 dedicated for this purpose.
[0069] According to an embodiment of the present invention, the timepiece
20 includes a mainspring winding level indicator
219 configured for indicating the state of the mainspring
201 during winding and unwinding.
[0070] It should be understood that numerous different embodiments of the timepiece, which
are functionally described above and shown in
Fig. 2, can be implemented without changing the timepiece function. Examples of construction
of the devices and mechanisms of the timepiece
20 shown in
Fig. 2 and its operation will be described hereinbelow in detail.
[0071] Fig. 3 illustrates a schematic plan view of a front side of the timepiece
20 shown in
Fig. 2, according to an embodiment of the present invention. It should be understood that
the present description will omit, for purpose of brevity, certain basic and very
well known concepts regarding the construction of mechanisms of the timepiece. However,
for purpose of supporting the claims and providing an enabling disclosure, certain
important components of such known mechanisms will be briefly described or referenced
throughout. For example, the basic construction of the mechanical power system
(200 in
Fig. 2) and arrangement of the mainspring
201 in the barrel
202 is not shown in
Fig. 3 in detail as being well within the purview of a person versed in the art. In should
also be noted that certain components of the timepiece
20 indicated in
Fig. 2 can be mounted on a rear side of the timepiece
20, and therefore these components are also not shown in
Fig. 3. The timepiece
20 can include a dial (not shown) provided with numerals or other indicia to assist
in reading time.
[0072] According to the embodiment shown in
Fig. 3, the main wheel train
(203 in Fig. 2) of the timepiece
20 can, for example, be a known wheel train described in detail in
U.S. Pat. No. 6,439,762. As shown in
Fig. 3, such a wheel train includes a second wheel
316 engaged with a third wheel
317 engaged with a second hand wheel
318 engaged with a fourth wheel
319 engaged with a fifth wheel
320. The second wheel
316 of the main wheel train
203 is engaged with the barrel
202 and configured to rotate the time indicating hands (not shown) in an ordinary manner.
In particular, a minute hand, which is not shown, can be coupled to the second wheel
316 through a cannon pinion (not shown), while a second hand can be affixed to the second
hand wheel
318. An hour wheel
326 can be affixed to the cannon pinion through a minute wheel
328, with an hour hand (not shown) being affixed to the hour wheel
326. The basic operation of the main wheel train
203 for transmitting the mechanical energy of the mainspring to rotate the time indicating
hands, will be omitted as being well within the purview of a person versed in the
art.
[0073] According to the embodiment shown in
Fig. 3, the manual winding and hand adjustment mechanism
(207 in
Fig. 2) of the timepiece
20 can, for example, be a known manual winding and hand adjustment mechanism
207 described in detail in
U.S. Pat. No. 6,439,762. As shown in
Fig. 3, such a manual winding and hand adjustment mechanism has a winding-up portion
320 and a hand adjusting portion
344.
[0074] The winding-up portion
320 includes a winding stem
301, the winding pinion
302, a crown wheel
303, an intermediate ratchet wheel
304 and a ratchet
224 associated with the mainspring. The mainspring can be wound by rotating a barrel
arbor
225 that is capable of rotating integrally with the ratchet
224. The ratchet
224 meshes with a click
306 so that it can rotate clockwise and cannot rotate counterclockwise. The ratchet
224 is constructed such that when the winding stem
301, connected to a crown (not shown), is operated, it rotates through the winding pinion
302, the crown wheel
303, and the intermediate ratchet wheel
304, and causes the barrel arbor
225 to rotate in order to wind up the mainspring.
[0075] The hand adjusting portion
344 of the manual winding and hand adjustment mechanism
207 is formed by the crown, the winding stem
301, a sliding portion
335, a setting wheel
336, an intermediate minute wheel
337, a minute wheel
328, a setting wheel
340, a click spring
341, and a yoke
342. Adjustments of the minute hand and the hour hand are performed by axially moving
the winding stem
301 by pulling out the crown, and by moving the sliding portion
335 towards the setting wheel
336 and engaging it therewith by the action of the setting lever
340, the click spring
341, and the yoke
342. Then, the cannon pinion associated with the second wheel
316 and the hour wheel
326 are rotated through the setting wheel
336, the intermediate minute wheel
337, and the minute wheel
328.
[0076] As described above, the torque regulation mechanism
218 is configured to control winding and unwinding of the mainspring for locking and
unlocking the barrel
202 in order to prevent damage of the control device
205, and for locking and unlocking the ratchet
224 to utilize the energy of the mainspring
201 when it operates at the non-liner regime.
[0077] The torque regulation mechanism
218 includes a ratchet wheel train
50a and an barrel wheel train
50b that can be known winding-up and unwinding wheel trains configuration and operation
of which are described in detail in
U.S. Pat. No. 6,439,762.
[0078] The torque regulation mechanism
218 also includes a first cam wheel
352, which is designed to cooperate with the ratchet wheel train
50a and the barrel wheel train
50b for stopping or allowing rotation of the barrel
202 and the ratchet
224, correspondingly.
[0079] As shown in
Fig. 3, the ratchet wheel train
50a are formed by consequently meshed wheels
58, 57, 56, 55, 54 and
53, and configured for transmitting torque from the ratchet wheel to the cam wheel
352. The barrel wheel train
50b is formed by consequently meshed wheels
62, 61, 60, 59 and
54, and configured for transmitting torque from the barrel
202 to the first cam wheel
352.
[0080] Referring to
Fig. 4, a schematic view of the first cam wheel
352 is shown, according to an embodiment of the present invention. As shown in
Fig. 4, the first cam wheel
352 is a disk-shaped wheel that has two grooves
411 and
413 along its outer periphery separated by cam periphery regions
412 and
414. Each grove and each cam periphery region are defined by corresponding angle sectors.
The arcs of such sectors have predetermined lengths; each length corresponds to a
predetermined number of rotations of the barrel
202.
[0081] In this embodiment, the speed reduction ratio from the barrel
202 and/or from the ratchet wheel
224 to the first cam wheel
352 is set at 1/12, so that when the number of windings of the mainspring is set at six
(the angle of rotation is 360 degrees x 6 = 2160 degrees), the first cam wheel
352 rotates 180 degrees.
[0082] Figs. 5A and 5B illustrate a schematic view of the torque regulation mechanism
218 in locked and unlocked states, correspondingly, according to an embodiment of the
present application. During winding the mainspring by rotating the ratchet
224, an amount of torque corresponding to the amount by which the mainspring is wound
up is transmitted to the first cam wheel
352 through the ratchet wheel train
50a, and is added as rotation of the first cam wheel
352 in a predetermined direction. Conversely, when the mainspring unwinds and the barrel
202 rotates, an amount of torque corresponding to the amount by which the mainspring
is unwound is transmitted to the first cam wheel
352 through the barrel wheel train
50b, and is subtracted as rotation of the first cam wheel
352 in the opposite direction.
[0083] According to an embodiment of the present invention, the torque regulation mechanism
218 also includes a ratchet lock mechanism
370 that is configured for locking the ratchet wheel train
50a for stopping rotation of the ratchet
224. The first cam wheel
352 is coupled to the ratchet lock mechanism
370, and can activate the ratchet lock mechanism
370 to stop or enable rotation of the ratchet
224 during winding.
[0084] The ratchet lock mechanism
370 includes a ratchet lock lever
371 which engages the wheel
58. The ratchet lock lever
371 can rotate around a rotation shaft
371a, disposed between the wheel
58 and the first cam wheel
352. The ratchet lock lever
371 can engage the wheel
58 and the first cam wheel
352. The ratchet lock lever
371 has a stopper portion
372 having a tooth
372a, which can engage the teeth of the wheel
58. The ratchet lock lever
371 also has an engaging portion
373 having a cam follower
373a. When the first cam wheel
352 rotates, the cam follower
373a can either engage the groove
411 of the first cam wheel
352 or be pressed against the cam periphery regions
412.
[0085] The ratchet lock lever
371 also has a spring portion
374, which extends from the body of the lever
371 so as to form a substantially U shape. The spring portion
374 presses against a stopper pin
375. The cam follower
373a is pressed against the first cam wheel
352 by the action of the spring portion
374. Therefore, when the cam follower
373a engages the groove
411 of the first cam wheel
352, the tooth
372a engages the wheel
58, as shown in
Fig. 5A. This locks the wheel
58 and stops its rotation, and thereby stops the rotation of the ratchet wheel train
50a and the ratchet
224. As a result the winding up of the mainspring is stopped.
[0086] Alternatively, when the cam follower
373a of the engaging portion
373 is pressed against a location of the cam periphery regions
412 of the first cam wheel
352, the tooth
372a, as shown in
Fig. 5B, is separated from the wheel
58, allowing the ratchet
204 to be rotated and thus the mainspring to be wound up.
[0087] As mentioned above, the first cam wheel
352 is set so that it rotates 180 degrees when the ratchet
224 rotates six times. Therefore, in the case where locking of the winding operation
is to be performed when the desired number of windings of the mainspring has been
reached, the first cam wheel
352 is set at an angle which causes the cam follower
373a to engage the groove
411 of the first cam wheel
352.
[0088] According to an embodiment of the present invention, the winding of the mainspring
201 is not ceased at the end of the linear torque region (i.e., at point C in
Fig. 1) that correspond to five windings of the mainspring, but is continued further until
the mainspring is wound up to a predetermined wound state. For example, the mainspring
can be wound up to 90% of the non-linear torque region that correspond to the number
of windings of the mainspring between five and six. In this case, the groove
411 is arranged close to the position indicated by a numerical number 0(6) in
Fig. 4.
[0089] However, when stopping the winding of the mainspring
201 (and thereby rotation of the ratchet
224) is desired at the end of the linear torque region (i.e., at point
C in
Fig. 1) (that is usually carried out in conventional timepieces together with stopping rotation
of the barrel), the number of windings of the mainspring can, for example, be set
at about five. As described above, this number of windings is defined by location
of the groove
411 on the periphery of the first cam wheel
352.
[0090] The torque regulation mechanism
218 also includes a barrel lock mechanism
380 configured for stopping or allowing rotation of the barrel
202. The first cam wheel
352 is coupled to the barrel lock mechanism
380, and can activate the barrel lock mechanism
380 to stop or enable rotation of the barrel
202.
[0091] As shown in
Figs. 5A and 5B, the barrel lock mechanism
380 has a barrel lock lever
381 configured for locking the unwind wheel train
50b which engages the wheel
61 that is coupled to the barrel
202 through the wheel
62. The barrel lock lever
381 rotates about a rotation shaft
381a, disposed between the wheel
61 and the first cam wheel
352. The barrel lock mechanism
380 includes a stopper portion
382 having a tooth
382a, which can engage the teeth of the wheel the wheel
61.
[0092] The barrel lock lever
381 also has an engaging portion
383 having a cam follower
383a. When the first cam wheel
352 rotates, the cam follower
383a can either engage the groove
413 of the first cam wheel
352 or be pressed against the cam periphery regions
414.
[0093] The barrel lock lever
381 also has a spring portion
384, which extends from the body of the lever
381 so as to form a substantially U shape and presses against a stopper pin
385. The stopper portion
382 and the engaging portion
383 press against the wheel
61 and the first cam wheel
352, respectively, by the action of the spring portion
384.
[0094] Accordingly, when the cam follower
383a of the engaging portion
383 engages the groove
413 of the first cam wheel
352, the tooth
382a of the stopper portion
382, as shown in
Fig. 5A, engages the wheel
61, thereby locking the rotation of the wheel
61, and thus the rotation of the unwind wheel train
50b, so that the unwinding of the rotation of the barrel
202 is stopped.
[0095] Alternately, when the cam follower
383a of the engaging portion
383 presses against a cam periphery region
414 of the first cam wheel
352, the tooth
382a of the stopper portion
382, as shown in
Fig. 5B, is separated from the wheel
61, allowing rotation of the unwind wheel train
50b, and thus allowing rotation of the barrel
202.
[0096] According to an embodiment of the present invention, the barrel lock lever
381 is set so that the tooth
382a of the stopper portion
382 engages the groove
413 of the first cam wheel
352 to lock the winding and unwinding operations of the barrel
202, when the desired number of winding operations has been performed. For instance, in
the case when the winding of the mainspring by rotating the ratchet
224 is not ceased at the end of the linear torque region (i.e., at point
C in
Fig. 1), but is rather continued further at the non-linear torque region that correspond to
the number of windings of the mainspring between five and six, the barrel
202 nevertheless can be stopped in this region in order to avoid damage to the regulation
device
(204 in
Fig. 2) by the large torque provided by the mainspring in the non-linear torque region
(CD in
Fig. 1 that is between the states
IV and
V of the mainspring). For example, when the speed reduction ratio from the barrel
202 to the first cam wheel
352 is set at 1/12, the groove
413 is arranged on the first cam wheel
352 between the position indicated by a numerical number 5 and 6 in
Fig. 4 which correspond to the number of windings of the mainspring between five and six.
[0097] As mentioned above, the non-linear torque region
(CD in
Fig. 1) can be used for driving the electric generator
(215 in
Fig. 2) during unwinding the mainspring from the fully wound state
(V in
Fig. 1) to the states
(IV in
Fig. 1). According to this embodiment, the electric generator
215 is driven by the ratchet
224 of mechanical power system
200 not only during winding the mainspring from completely unwound state (
I in
Fig. 1) to the state
(V in
Fig. 1) in which the mainspring is fully wound, but also during unwinding the mainspring
from the fully wound state (or almost fully wound state that is selected near the
end of the non-linear torque region (point D in the graph in
Fig. 1)) to a predetermined wound state that is selected at the beginning of the linear
torque region, e.g., at or near the point
E in the graph in
Fig. 1. This is achieved by enabling a reverse rotation of the ratchet only when the mainspring
201 unwinds in the non-linear torque regime, and blocking the reverse rotation of the
ratchet when the mainspring unwinds to the beginning of the linear torque region (point
E in the graph in
Fig. 1).
[0098] In order to enable the reverse rotation of the ratchet only when the mainspring
201 unwinds in the non-linear torque regime, the torque regulation mechanism
218 includes a click lifting mechanism
390 configured for releasing the ratchet
224 and enabling rotation of the ratchet
224 in a direction that is reverse to the rotation of the ratchet
224 during winding the mainspring. Accordingly, the click lift mechanism
390 is configured for lifting the click
306 in cooperation with ratchet lock mechanism
370, in order to release the ratchet
224 so that the ratchet
224 could rotate not only in the direct rotation (i.e., clockwise) during winding of
the mainspring, but also in a reverse direction (i.e., counterclockwise), when the
mainspring unwinds. The counterclockwise rotation of the ratchet can be used during
the non-linear operation regime of the mainspring (i.e., region
DE in
Fig. 1).
[0099] According to an embodiment of the present invention, the click lifting mechanism
390 includes a click lift lever
391 configured for lifting the click
306 up, a pusher lever
396 engaged with the click lift lever
391 and with a second cam wheel
353.
[0100] The click lift lever
391 has a first arm
391a and a second arm
391b, and can rotate around a rotation shaft
392. The rotation shaft
392 can, for example, be arranged on a plate
393 disposed between the wheel
58 and the click
306. The click lift lever
391 also has a spring portion
391c, which extends from the body of the lever
391 so as to form a substantially U shape.
[0101] As shown in
Fig. 5A, when the pusher lever
396 does not press the second arm
391b of the click lift lever
391, the spring portion
391c has an original shape and the first arm
391a lifts the click
306 up, thereby enabling the ratchet
224 to rotate not only in the direct direction during winding but also in the reverse
direction during unwinding, e.g., during the region
DE in
Fig. 1.
[0102] Alternatively, as shown in
Fig. 5B, when the pusher lever
396 presses against the second arm
391b, the spring portion
391c is stretched. In this state, the first arm
391a does not press the click
306 and the click
306 lifts down and engages teeth
397 of the ratchet
224, thereby preventing rotation of the ratchet
224 in the reverse direction during unwinding.
[0103] As shown in
Figs. 5A and 5B, there are two stopper pins
394 and
395 which are provided on the plate
393. The spring portion
391c is pressed against the stopper pin
394, while the stopper pin
395 limits displacement of the second arm
391b when the pusher lever
396 is pressed against the second arm
391b.
[0104] Referring to
Fig. 6, a schematic view of the second cam wheel
353 is shown, according to an embodiment of the present invention. As shown in
Fig. 6, the second cam wheel
353 is a disk-shaped wheel that has a projecting portion
601 along its outer periphery. The projecting portion
601 is defined by a corresponding angle sector. The arc of this sector has a predetermined
length that corresponds to a predetermined number of rotations of the ratchet.
[0105] In this embodiment, the second cam wheel
353 has an arbor common with the arbor of the first cam wheel
352. The second cam wheel
353 is mounted on and coupled to the first cam wheel
352. Accordingly, the second cam wheel
353 can be rotated concurrently and in phase with the first cam wheel
352. Therefore, when desired, the second cam wheel
353 can be formed integrally with the first cam wheel
352.
[0106] A spatial relation in the torque regulation mechanism
218 between the first cam wheel
352, the second cam wheel
353, the ratchet lock lever
371, the barrel lock lever
381 and the pusher lever
396 is also shown in
Fig. 7.
[0107] As mentioned above, the total number of windings of the mainspring (e.g., six) corresponds
to the angle of rotation of the first
352 and second
353 cam wheels of 180 degrees. Accordingly, this angle can be used as indication of the
winding state of the mainspring.
[0108] Thus, as shown in
Fig. 7, according to an embodiment of the present invention, the mainspring winding level
indicator
(219 in Fig. 2) includes a needle (indicated by a reference numeral
701) that is affixed to the arbor of the first and second cam wheels
352 and
353, and a sub-dial (not shown) marked with indicia. The indicia can, for example, correspond
to the operation hours of the timepiece
(219 in Fig. 2) until the total unwinding of the mainspring.
[0109] Referring to
Figs. 3, 5A, 5B, 6 and 7 together, the pusher lever
396 can rotate around the rotation shaft
371a, which the pusher lever
396 shares with the ratchet lock lever
371. The pusher lever
396 can press the click lift lever
391 and engage the second cam wheel
353. The pusher lever
396 has a pusher portion
377, which can press the second arm
391b of the click lift lever
391. The pusher lever
396 also has an engaging portion
378 having a cam follower
378a. When the second cam wheel
353 rotates, the cam follower
378a of the pusher lever
396 can either press the projecting portion
601 of the second cam wheel
353 or press against the cam region which is the other region on the outer periphery
of the second cam wheel
353 than the projecting portion
601.
[0110] The pusher lever
396 also has a spring portion
379, which extends from the main body of the pusher lever
396 so as to form a substantially U shape. The spring portion
379 can press against the stopper pin
375, which is also used to limit rotation of the pusher lever
396.
[0111] The cam follower
378a is pressed against the second cam wheel 353 by the action of the spring portion
374. Therefore, when the cam follower
378a presses the projecting portion
601 of the second cam wheel
353, as shown in
Fig. 5A, the pusher portion 377 does not press the second arm
391b of the click lift lever
391. Accordingly, as described above, the first arm
391a of the click lift lever
391 lifts the click
306 up. As a result, the ratchet
224 is able to rotate not only in the direct direction during winding but also in the
reverse direction during unwinding, e.g., during the region
DE in
Fig. 1.
[0112] Alternatively, when the cam follower
378a of the of the pusher lever
396 is pressed against a region which is the other region on the outer periphery of the
second cam wheel
353 than the projecting portion
601, the pusher portion
377 of the pusher lever
396 presses against the second arm
391b. In this state, as mentioned above, the first arm
391a does not press the click
306 and the click
306 engages the teeth
397 of the ratchet
224. As a result, the ratchet
224 is able to rotate only in direct direction during winding and is not able to rotate
in the reverse direction during unwinding.
[0113] As mentioned above, the pusher lever
396 is set so that the cam follower
378a presses the projecting portion
601 of the second cam wheel
353 only, when the desired number of winding operations has been performed. According
to an embodiment of the present invention this number corresponds to the end of the
non-linear torque regime of the mainspring due to the friction between the coils of
the mainspring. For example, in the embodiment, when the number of the windings of
the mainspring is set at six, the non-linear torque regime corresponds to the number
of the windings between about five and six. Thus, the winding and unwinding of the
mainspring in the non-linear torque regime region is carried out when the click
306 is lifted. Accordingly, the ratchet in the non-linear torque regime of the mainspring
can rotate not only in the direct direction (i.e., clockwise), but also in the reverse
direction (i.e., counterclockwise). As mentioned above, the clockwise rotation of
the ratchet during winding and the counterclockwise rotation of the ratchet during
unwinding in the non-linear torque regime of the mainspring can be used for driving
the electric generator
(215 in
Fig. 2).
[0114] As mentioned above, the electric generator
(215 in
Fig. 2) can be driven by one or concurrently by several mechanisms that provide a power for
charging the electric battery
(212 in
Fig. 2).
[0115] Referring to
Fig. 8, a schematic perspective view of the generator transmission mechanism
217 in
Fig. 2) for driving the generator
215 is illustrated, according to an embodiment of the present invention. The generator
transmission mechanism
217 includes a ratchet torque transmission train
810 that is coupled to the ratchet
224. The ratchet torque transmission train
810 is configured for transmitting a torque from the ratchet
224 during rotation of the ratchet in a direct direction when the user rotates the winding
crown to wind the mainspring up. Thus, the rotation of the ratchet during winding-up
can drive the electric generator
215 when the mainspring is wound from completely unwound state (
I in
Fig. 1) to the state
(V in
Fig. 1) in which the mainspring is fully wound. Accordingly, in this case, the electric generator
215 can be driven by the winding-up portion
(320 in Fig. 3) of the manual winding and hand adjustment mechanism
207 that rotates the ratchet
224 coupled to the generator through the ratchet torque transmission train
810.
[0116] The torque from the ratchet
224 can also be transmitted to the generator
215 when the ratchet
224 rotates in a reverse direction during unwinding of the mainspring in the non-linear
torque regime region from the state
(V in
Fig. 1) in which the mainspring in the fully wound state (that is selected near the end of
the non-linear torque region corresponding to the point
D in the graph in
Fig. 1) to a predetermined wound state, for example, to the state
(IV in
Fig. 1) that corresponds to the beginning of the linear torque region (point
E in the graph in
Fig. 1). As described above, this is achieved by enabling a reverse rotation of the ratchet
224 only during the non-linear torque regime.
[0117] According to an embodiment of the present invention, the ratchet torque transmission
train
810 includes an intermediate wheel
811 that is engaged with the ratchet
224. The ratchet torque transmission train
810 further includes a unidirectional coupling-clutch device
812 having a coupling-clutch pinion
1 that is engaged with the intermediate wheel
811 and a coupling-clutch wheel
6.
[0118] The unidirectional coupling-clutch device
812 is configured such that rotation of the coupling-clutch wheel
6 in a predetermined direction (e.g., clockwise) causes engagement the coupling-clutch
wheel
6 with the coupling-clutch pinion
1 and driving the pinion
1 by the coupling-clutch wheel
6. On the other hand, rotation of the coupling-clutch wheel
6 in the opposite direction (e.g., counterclockwise) results in a free rotation of
the coupling-clutch wheel
6 with respect to the pinion
1 without their engagement.
[0119] According to this embodiment, the unidirectional coupling-clutch device
812 can, for example, be a unidirectional coupling-clutch runner described in detail
in
U.S. Pat. No. 8,337,077.
[0120] Fig. 9 shows a perspective top view of this unidirectional coupling-clutch runner of Pat.
No.
8,337,077. The unidirectional coupling-clutch runner includes a coaxial pinion
1 and a coupling-clutch wheel
6 which pivot relative to one another. The runner includes a first driving part
14 angularly integral with the pinion
1 having at least one elastic catch
15 with the general shape, in plan view, of a C, one branch of which is elongated and
terminates with a free end; and a second driving part
17 angularly integral with the wheel
6 and which is coplanar with the first driving part
14 having an internal wolf-toothing
16. In the neutral rest position the first and second driving parts
14, 17 do not touch one another, the end of the elastic catches
15 in the rest position which are not elastically deformed being located on a circumference
whose diameter is larger than a circumference which goes through the top of the wolf-teeth
16 and smaller than a circumference going through the bottom of the toothing
16 of the second driving part.
[0121] As reported in
U.S. Pat. No. 8,337,077, such a coupling-clutch runner can transmit in one direction of rotation a considerable
torque grater than 1000 gr. mm without damage. It also has a resistance torque in
the opposite direction of rotation less than 10 gr. mm.
[0122] The ratchet torque transmission train
810 also includes a speed increase wheel
815 that is engaged with the coupling-clutch wheel
6 and with a generator wheel
816 mounted on a rotation shaft
817 of the generator
215. The speed increase wheel
815 is configured for transmitting a torque from the unidirectional coupling-clutch device
812 to the generator
215 with a predetermined speed increase rate.
[0123] As mentioned above, when the timepiece is moved, the electric generator
215 can also be driven by the automatic winding mechanism
208. The automatic winding mechanism
208 can be coupled to the electric generator
215 through an automatic winding train
820 of the generator transmission mechanism
217.
[0124] The automatic winding train
820 includes a tension wheel
821 and a reduction rate wheel
822 which are part of the automatic winding mechanism
(208 in
Fig. 2), known to those versed in the art. The automatic winding mechanism
208 is configured for transmitting the energy associated with the movements of the timepiece
wearer to the generator
215. The automatic winding mechanism
208 uses the rotation of an oscillating weight (not shown) to transfer and store mechanical
energy in the barrel
202 through the automatic winding train
820 forming a kinematic chain, which meshes with weight pinion (not shown) of the oscillating
weight. Because of the shift in the centre of gravity of oscillating weight relative
to its axis of rotation, the user's wrist movements cause this oscillating weight
to rotate relative to the watchcase.
[0125] The rotation of oscillating weight is transferred to the ratchet
224 through the kinematic chain formed by a pair of reverser wheels (not shown) which
mesh with the tension wheel
821 which meshes with the reduction rate wheel
822. A pinion
823 of the reduction rate wheel
822 meshes with the coupling-clutch wheel
6 of the unidirectional coupling-clutch device
812.
[0126] One of the reverser wheel meshes with the pinion of the oscillating mass so that
torque from the oscillating mass is transferred through this reverser wheel directly
to the tension wheel
821 during one rotation of the oscillating mass. When the direction of rotation of the
oscillating mass changes, the torque from the oscillating mass is transferred through
another reverser wheel. This results in rotation of the tension wheel
821 always in one direction regardless of which direction the pinion of oscillating mass
turns.
[0127] When the rotation of the reduction rate wheel
822 is in the direction that causes engagement of the coupling-clutch wheel
6 with the coupling-clutch
1 pinion, the torque associated with the user's wrist movements are transferred to
the ratchet
224 through the intermediate wheel
811 for winding the mainspring, and to the generator wheel
816 through the speed increase wheel
815 for driving the electric generator
215.
[0128] According to the generator transmission mechanism
217 is of the type that only winds in one direction, owing to unidirectional coupling-clutch
device
812. Thus, the unidirectional coupling-clutch device
812 disengages the speed increase wheel
815 from the automatic winding train
820 when the ratchet is rotated in the opposite rotation to the winding rotation, because
the coupling-clutch
1 pinion rotates free with respect to the coupling-clutch wheel
6.
[0129] The electrical energy produced by the electric generator
215 is fed to the rechargeable electric battery
(212 in Fig. 2) through the battery charge controller
(216 in. Fig. 2) configured to control the charging process. The control of the charging process can
be carried out by maintaining a required charging electric current for providing an
output voltage by the battery
212 within desired magnitudes. The basic construction the battery charge controller will
be omitted as being well within the purview of a person versed in the art.
[0130] As mentioned above with reference to
Fig. 2, the total torque that drives the timepiece
20 is the torque output applied to the main wheel train from the mainspring
201 combined with the torque provided by the electric motor
210. Since the torque output from the mainspring
201 decreases as the mainspring unwinds, this additional torque provided by the electric
motor
210 can,
inter alia, drive the main wheel train
203 when the torque associated with the friction in the wheel train exceeds the torque
provided by the mainspring (i.e., section
AG in
Fig. 1). As described above, conventional timepieces cannot normally operate when the torque
decreases below the magnitude corresponding to point
G in the graph in
Fig. 1, because below the magnitude corresponding to point
G the hands of a conventional timepiece gradually slow down, and finally the timepiece
stops operating. Thus, according to an embodiment of the present invention, the timepiece
20 is driven by the electric motor
210 when the mainspring
201 is unwound beyond point
G. Accordingly, the timepiece
20 can be driven for a longer continuous operating time than a conventional timepiece.
[0131] According to a further embodiment of the present invention, the electric motor
210 assists to drive the main wheel train
203 also at the linear torque regime between the states
II and
IV in
Fig. 1 during unwinding of the mainspring. This enables maintaining the total torque that
drives the timepiece at a predetermined magnitude close to a certain optimal magnitude
Mopt.
[0132] It should be relevant to note that employment of an electric motor for assisting
in driving the main wheel train as proposed by the present application has certain
advantages over the prior art techniques where electric motors were used for winding
the mainspring. Indeed, a torque for winding a mainspring by an electric motor should
have a magnitude significantly greater than the torque for assisting the mainspring
to maintain the total torque that drives the main wheel train at a predetermined magnitude
close the optimal magnitude
Mopt. It should be understood that the provision of the present application requires less
powerful electric motors, less powerful batteries for driving such electric motors,
and correspondingly less space inside of the timepiece that is needed for installation
of the motor and battery within a timepiece, than in the case when a powerful motor
should be used for winding the mainspring. Referring to
Fig. 3 and Fig. 10 together, the electric motor
210 is engaged with the main wheel train
203 through the electric motor transmission mechanism
211, so as to provide an additional controllable torque output for driving the time indicating
hands
(209 in Fig. 2). According to this embodiment, the electric motor
210 is coupled to the third wheel
317 of the main wheel train
203 through the electric motor transmission mechanism
211.
[0133] There are several advantages for applying the torque provided by the electric motor
to the third wheel
317. In particular, a torque magnitude can be less when an electric motor is coupled to
an intermediate wheel rather than in the case when an electric motor is coupled to
the barrel or to the second (central) wheel
316. Accordingly, less powerful electric motors and less powerful batteries for driving
such electric motors can be used. Moreover, since the third wheel
317 is located in the central portion of the timepiece, the technical solutions for implementation
of the electric motor transmission mechanism
211 for coupling the electric motor
210 to the main wheel train can be simplified when compared to coupling to a wheel located
at the periphery. The technical solutions for implementation of a kinematic chain
of the electric motor transmission mechanism
211 are determined by the configuration of the main wheel train
203, e.g., the arrangement of a second hand (centre-mounted or provided with a sub-dial),
and also by the presence of additional indicator devices, e.g., calendar, the availability
of free space inside the timepiece case, etc. The number and dimension of the wheels
in the electric motor transmission mechanism
211 are determined by a condition for the reduction rate coefficient of the electric
motor transmission mechanism
211 to meet the rotation rate of the third wheel
317.
[0134] According to the embodiment shown in
Figs. 3 and 10, the electric motor transmission mechanism
211 includes an intermediate wheel
24 that meshes with a motor wheel
25 associated with a rotor shaft of the electric motor
210. The electric motor transmission mechanism
211 also includes a reduction wheel pair
23 that is engaged with a friction clutch
22 that is engaged with the third wheel
317. In particular, the intermediate wheel
24 meshes with one wheel
23a of the reduction wheel pair
23, whereas another wheel
23b of the reduction wheel pair
23 meshes with a driving wheel
22a of the friction clutch
22. A driven pinion
22b of the friction clutch
22 meshes with the third wheel
317. A driving torque from the driving wheel
22a of the friction clutch
22 to the driven pinion
22b is transmitted via a spring (not shown) that can control the maximal magnitude of
the torque transferred from the electric motor
210 to the third wheel
317. In turn, the torque is further transmitted to the escapement
206 trough the wheels
318, 319 and
320. In operation, the friction clutch
22 provides a periodic slippage between the driving wheel
22a and the driven pinion
22b, thereby "smoothing" the intermittent rotation of the escapement. Accordingly, implementation
of the electric motor transmission mechanism
211 with such a friction clutch rather than with a regular wheel, simplifies construction
of the electric motor transmission mechanism
211, improves the reliability of its work and extends the range of types of asynchronous
electric motors that can be used with the timepiece
20.
[0135] Referring to
Figs. 2 and 10 together, in order to control operation of the electric motor
210, the timepiece regulating device
204 of the timepiece
20 includes a balance oscillation controller
214. According to an embodiment, the balance oscillation controller
214 includes a detecting unit
101 and a processing unit
102 electrically coupled to detecting unit
101. The detecting unit
101 is configured for measuring rotational operation the balance
205 for determining an oscillation period of the balance
205 that is decreased when the mainspring torque is reduced. The processing unit
102 is configured for processing the data measured by the detecting unit
101, and when the measured data deviate from predetermined magnitudes, generating control
signals and relaying them to the electric motor controller
213 for driving the electric motor
210 in order to provide an additional controllable torque to the torque provided by the
mainspring for driving the main wheel train
203.
[0136] According to an embodiment, the detecting unit
101 includes an electromagnetic transmitter
103 arranged at one side of the balance
205 and configured for generating an electromagnetic radiation and irradiating an arm
portion
104 of the balance
205 (i.e., the portion of the balance
205 where balance arms
105 are arranged). The electromagnetic transmitter
103 can, for example, include an optical emitter, such as a light emitting diode (LED),
a laser diode, etc. However, electromagnetic transmitters that operate in other electromagnetic
frequency bands are also contemplated.
[0137] The detecting unit
101 also includes an electromagnetic receiver
106 arranged at the opposite side of the balance
205 and positioned in an optical path so that a field of view of the electromagnetic
receiver
106 ensures the capture of a part of the radiation which is transmitted by the electromagnetic
transmitter
103 and irradiated the arm portion
104 of the balance
205. Thus, the arm portion
104 of the balance
205 is disposed between the electromagnetic transmitter
103 and the electromagnetic receiver
105. The electromagnetic receiver
106 can, for example, include an optical detector, such as a photodiode or other photo-receiving
device, however receiving devices that operate in other electromagnetic frequency
bands are also contemplated.
[0138] In operation, the balance arm portion
104 rotates between the electromagnetic transmitter
103 and the electromagnetic receiver
106. When the balance arm
105 is disposed between the electromagnetic transmitter
103 and the electromagnetic receiver
105, the radiation emitted by the electromagnetic transmitter
103 is blocked by the balance arm
105, and therefore is not detected by the electromagnetic receiver
106. On the other hand, when the balance arm
105 is not disposed between the electromagnetic transmitter
103 and the electromagnetic receiver
106, the radiation emitted by the electromagnetic transmitter
103 is reached, and is therefore detected by the electromagnetic receiver
106. It should be understood that the period of the radiation incident on the electromagnetic
receiver
106 corresponds to the oscillation period of the balance
205.
[0139] The electromagnetic receiver
106 generates a signal indicative of the period of the detected radiation and relays
this signal to the processing unit
102. The control processing unit
102 is typically a computing system, for example, in the form of an integrated circuit
(IC), having,
inter alia, such known utilities as a memory unit (not shown) and a processor (data acquisition
and processing utility).
[0140] According to an embodiment of the present invention, the memory unit is configured
for storing a relationship between an oscillation period of the balance
205 and a torque driving the main train wheel
203. The memory unit also stores the optimal magnitude (
Mopt in Fig. 1) of the operating torque driving the main train wheel
203 at which operation of the timepiece is precise.
[0141] According to an embodiment of the present invention, the processor is preprogrammed
by a suitable software model capable of analyzing the received data (i.e., output
signal of the electromagnetic receiver
106). The analyzing the received data includes calculating the operating torque and generating
a deviation indication signal (and a corresponding control signals for the electric
motor controller
213), if the calculated operating torque deviates from the optimal torque magnitude
Mopt, that correspond to precise operation of the timepiece.
[0142] In particular, since the mainspring torque during unwinding of the mainspring at
the beginning and end of the linear torque regime between the states
II and
IV in
Fig. 1, can deviate from the optimal magnitude
Mopt, the balance oscillation controller
214 can generate a corresponding deviation indication signal, and relay this signal to
the electric motor controller
213. Responsive to this signal, the electric motor controller
213 can generate a train of driving pulses for activating and driving the electric motor
210 to adjust the total magnitude of the operational torque for maintaining the total
torque that drives the main train wheel of the timepiece at the optimal magnitude
Mopt.
[0143] Likewise, when during unwinding the mainspring reaches a state corresponding to point
G in the graph in
Fig. 1 and leaves the linear operation regime, the balance oscillation controller
214 can generate a deviation indication signal indicating decrease of the oscillation
period of the balance
205, and relay this signal to the electric motor controller
213. Responsive to this signal, the electric motor controller
213 can generate a train of driving pulses for activating and driving the electric motor
210 as long as required.
[0144] As such, those skilled in the art to which the present invention pertains, can appreciate
that while the present invention has been described in terms of preferred embodiments,
the concept upon which this disclosure is based may readily be utilized as a basis
for the designing of other structures and processes for carrying out the several purposes
of the present invention.
[0145] Also, it is to be understood that the phraseology and terminology employed herein
are for the purpose of description and should not be regarded as limiting.
[0146] It is important, therefore, that the scope of the invention is not construed as being
limited by the illustrative embodiments set forth herein. Other variations are possible
within the scope of the present invention as defined in the appended claims.