Technical Field
[0001] The present invention relates to an elevator system wherein a hoisting machine is
mounted on an elevator car or a counterweight.
Background Art
[0002] With a view to reduce the required space in the hoistway of an elevator as much as
possible, there have been suggested elevator systems wherein the hoisting machine
is mounted on the elevator car or the counterweight. For example, in Japanese non-examined
laid-open patent publication No. Hei 9-124259, there is disclosed an elevator system
wherein the hoisting machine is mounted on the counterweight.
[0003] However, although the elevator of the type with the hoisting machine mounted on the
elevator car or the counterweight has the great advantage of saving space, there is
the problem that rescue of trapped passengers in the elevator car due to malfunction
of the control device of the elevator is difficult. In the above-mentioned Japanese
non-examined laid-open patent publication No. Hei 9-124259, there is disclosed a means
for rescuing passengers in an emergency using a manually-operated winding unit. However,
rescue by this method has the problem that it is limited to malfunction in the situation
where electrical control of opening and closing of the braking device of the hoisting
machine mounted on the counterweight is possible. Therefore, it is often the case
that it is difficult to drive the elevator by means of a manually-operated winding
unit in the event that opening and closing of the braking device from the ground becomes
impossible due to malfunction, thus this type still remains with problems.
[0004] On the other hand, in Japanese non-examined laid-open patent publication No. Hei
5-147855, there is disclosed a method by which a braking device to brake the elevator
car or the counterweight by gripping the guiderails corresponding to the elevator
car or the counterweight, with a method of releasing the grip on the guiderails by
actuating a lever by using a rope passed around a pair of pulleys provided in an upper
part and a lower part of the hoistway and stretched in a loop shape, is disclosed.
However, since this braking device has the method of pulling the rope which is coupled
with the lever only downward, in the case where, for example, the braking device is
provided on the elevator car side, when the elevator car is heavier than the counterweight
depending on the situation of the number of persons in the car, the elevator car,
of which the grip of the guiderails is released, starts descending once the lever
is actuated. That is, because the elevator car moves in the direction which force
is exerted by the lever, release of brake of the braking device by the lever cannot
always be performed accurately. In other words, there are case where release of brake
cannot be performed properly depending on the increase and decrease in the number
of persons riding in the car.
[0005] The present invention has as its intension to enable rescue of passengers by making
it possible for a maintenance worker to mechanically release brake of the braking
device from the ground floor in the event that electrical control of opening and closing
of the braking device becomes impossible when the elevator stops between floors due
to malfunction, and afterwards to move the elevator car to a nearest floor, in an
elevator system having a hoisting machine and a braking device mounted on the elevator
car or the counterweight.
[0006] The present invention also has as its intension to enable more stable release of
brake of the braking device, regardless of the number of persons riding in the elevator
car.
Disclosure of the Invention
[0007] The elevator system in the present invention comprises an elevator car which ascends
and descends through the hoistway and a counterweight which travels in the direction
opposite to the elevator car; and a hoisting machine is mounted on either the elevator
car or the counterweight. A main rope which suspends the elevator car and the counterweight
is passed around a drive sheave of the hoisting machine. A braking device which applies
brake to the hoisting machine by means of brake springs and also releases brake of
the hoisting machine by means of an excited electromagnet by resisting the brake springs
is provided on the hoisting machine.
[0008] Furthermore, a brake-releasing mechanism for releasing brake of the braking device
mechanically by resisting the brake springs is provided on the hoisting machine, separately
from the braking device. The brake-releasing mechanism has brake-releasing levers
for releasing brake of the braking device by retracting the brake springs, and operation
ropes for operating the brake-releasing levers wound around a pair of pulleys which
are provided in a part higher and lower than either of the travel area of the elevator
car or the counterweight and stretched between the pulleys ; and the brake-releasing
levers and the operation ropes are connected via a connecting means.
[0009] Moreover, the brake-releasing mechanism is comprised of the below-mentioned two sets
of brake-releasing mechanisms (a first and a second). That is, the brake-releasing
mechanism is comprised of a first brake-releasing mechanism having a first pair of
pulleys, a first operation rope and a first brake-releasing lever, wherein the operation
rope is pulled up so as to release brake of the braking device; and a second brake-releasing
mechanism having a second pair of pulleys, a second operation rope and a second brake-releasing
lever, wherein the operation rope is pulled down so as to release brake of the braking
device.
[0010] According to the aforementioned invention, even in the case where electrical control
of opening and closing of the braking device becomes impossible in the event that
the elevator stops between floors due to malfunction, it is possible for a maintenance
worker to mechanically release brake of the braking device from the ground, and to
move the elevator car to a nearest floor and rescue the passengers. Further, as the
elevator system comprises two - a first and second - sets of brake-releasing mechanisms,
it is possible to select the brake-releasing mechanism suited to the situation of
the riding of the car and to perform a more stable releasing operation of the braking
device with facility and also without fail, regardless of the number of persons riding
in the elevator car.
Brief Description of the Drawings
[0011]
Figure 1 is a diagram showing an example of an arrangement of the elevator system
in accordance with the first embodiment of the present invention;
Figure 2 is a diagram for explaining the structures of the braking device of the hoisting
machine and the brake-releasingmechanismmounted on the counterweight in accordance
with the first embodiment of the present invention;
Figure 3 is an elevation for explaining the motion of opening and closing of the braking
device in accordance with the first embodiment of the present invention;
Figure 4 is an elevation for explaining the motion of the first brake-releasing mechanism
in accordance with the first embodiment of the present invention;
Figure 5 is an elevation for explaining the motion of the second brake-releasing mechanism
in accordance with the first embodiment of the present invention; and
Figure 6 is an elevation for explaining the structure of the brake-releasing mechanism
of the braking device in accordance with the second embodiment of the present invention.
Best Mode for Carrying out the Invention
[0012] To describe the present invention in more detail, the invention will be described
by referring to the accompanying drawings. In each of the drawings, the same numerals
are given to the same parts or the corresponding parts, and repeated explanation will
be appropriately simplified or omitted.
First Embodiment
[0013] Figure 1 is a diagram showing an example of an arrangement of the elevator system
in accordance with the first embodiment of the present invention; Figure 1(A) is an
elevation of the elevator system viewed from the horizontal direction, and Figure
1(B) is a plan view of the elevator system viewed from above.
[0014] First: the whole structure of the elevator system in accordance with the first embodiment
will be explained referring to Figure 1. Inside the hoistway 1, there are provided
a pair of guiderails 2 for the elevator car and another pair of guiderails 3 for the
counterweight. The elevator car 4 travels through the hoistway 1 guided by the guiderails
2 for the elevator car, and the counterweight 10 travels through the hoistway guided
by the guiderails 3 for the counterweight in the direction opposite to the car 4.
[0015] Entrance doors 4a are provided on the front surface of the car 4, and hall doors
5 are provided on the hall side, facing the entrance doors 4a. The counterweight 10
is arranged between the rear surface of the car 4 and the wall of the hoistway 1.
[0016] Next: the hoisting machine 11 is mounted on the counterweight 10. On the hoisting
machine 11, a braking device 20 which performs opening and closing of brake of the
hoisting machine 11 is provided. Furthermore, both ends of the main rope 6 which suspends
the elevator car 4 and the counterweight 10 are fixed to an upper part of the hoistway
1, and one of the ends of the main rope 6 is successively wound around a pair of suspension
sheaves 7 provided in a lower part of the elevator car 4 starting at the upper part
of the hoistway 1, and reaches the direction-changing pulley 8 which is provided in
an upper part of the hoistway 1. After it is wound around the direction-changing pulley
8, it is wound around the drive sheave 12 of the hoisting machine 11 mounted on the
counterweight 10, and rises again, and the other end of the main rope 6 is fixed to
the upper part of the hoistway 1.
[0017] Next: the brake-releasing mechanism used in the first embodiment comprises two sets
- a first and a second - of brake-releasing mechanisms . The first brake-releasing
mechanism 30 has a first brake-releasing lever 31 for mechanically releasing brake
of the braking device 20, a pair of first pulleys 32 which are separately provided
in a part higher and lower than the travel area of the counterweight 10, and a first
operation rope 33 which is passed around the first pulleys 32 and stretched in a loop
shape between the first pulleys 32. Similarly, the second brake-releasing mechanism
40 has a second brake-releasing lever 41, second pulleys 42, and a second operation
rope 43.
[0018] Figure 2 is a diagram for explaining the structures of the braking device of the
hoisting machine and the brake-releasingmechanismmounted on the counterweight in accordance
with the first embodiment of the present invention; Figure 2(A) is an elevation of
the braking device of the hoisting machine viewed from the horizontal direction, and
Figure 2(B) is a cross sectional view taken on line C-C of the braking device.
[0019] In Figure 2, the external form of the counterweight 10, on which the hoisting machine
11 is mounted, is comprised of a frame body 14, and a weight 15 for the counterweight
is mounted in a lower part inside the frame body 14. The hoisting machine 11 comprises
a drive sheave 12 around which the main rope 6 is passed, and an electric motor 13
for rotatably driving the drive sheave 12.
[0020] Next: the braking device 20 is structured as a part of the hoisting machine 11; and
a brake drum 21 is arranged on the same rotation axis as the drive sheave 12 of the
hoisting machine 11. A pair of brake shoes 22 is provided facing the circumferential
surface of the brake drum 21; and each of the brake shoes 22 is fixed to the brake
arms 23. The brake arms 23 receive the force of the braking springs 24 provided between
themselves and a side part of the frame body 14 of the counterweight 10, and stops
rotation of the brake drum 21 by pressing the brake shoes 22 to the brake drum 21.
One of the ends of the brake arms 23 are fixed to the frame body 14 of the counterweight
10 via brake arm pins 23a, and the brake arms 23 pivot with the brake arm pins 23a
as their centers. On the other end of the brake arms 23, bolts 25 are fixed, and the
brake arms 23 are coupled with brake levers 26 via the bolts 25. The brake levers
26 pivot with brake lever pins 26a as their centers. An electromagnet which drives
the braking device 20 is housed in a casing 27 provided on an upper part of the frame
body 14 of the counterweight 10. Here in the first embodiment, a plunger 28 is used
as a pushing body which is driven by the excited electromagnet. A plunger head 28a,
which is an end part of the plunger 28, abuts on the brake levers 26.
[0021] Next: in the first brake-releasing mechanism 30, the first brake-releasing lever
31 is formed in a longitudinal shape, and on one end thereof there is provided a pierced
first releasing-lever hole 35. The plunger 28 is inserted into this first releasing-lever
hole 35. Here, the plunger head 28a is formed to have a larger diameter than the part
of the plunger 28 that is inserted into the first brake-releasing lever 31. For this
reason, it is possible to couple the plunger head 28a with one end of the first brake-releasing
lever 31. In the present invention, this coupling part of the first brake-releasing
lever 31 will be referred to as the first releasing-lever coupling part 34. Furthermore,
the first brake-releasing lever 31 uses as a supporting-point base 29 a part of the
casing 27 which is close to the first brake-releasing lever coupling part 34 and in
which the electromagnet is housed; and the supporting point of the first brake-releasing
lever 31 is supported by the supporting-point base 29. The other end of the first
brake-releasing lever 31 is connected to the first operation rope 33 by means of a
connection means. In the first embodiment, an example in which the first brake-releasing
lever 31 is constantly fixed to the first operation rope 33 is shown.
[0022] Furthermore, in the second brake-releasing mechanism 40, the brake-releasing lever
41 is formed in a longitudinal shape, with the middle part formed in a square-loop
shape which surrounds the plunger head 28a. Similarly to the first brake-releasing
lever 31, one end of the second brake-releasing lever 41 uses as a supporting point
the supporting-point base 29 of the casing 27 of the electromagnet, and normally one
end is in a state in which it abuts on the supporting-point base 29. The middle part
of the second brake-releasing lever 41 has a second releasing-lever coupling part
44 between itself and the plunger head 28a, and is pivotally connected to the plunger
head 28a via the second releasing-lever pin 45. The other end of the second brake-releasing
lever 41 is connected to the second operation rope 43 by means of a connection means.
In the first embodiment, similarly to the first brake-releasing lever 31, an example
in which the second brake-releasing lever 41 is constantly fixed to the second operation
rope 43 is shown.
[0023] Also, on the side parts of the frame body 14 of the counterweight 10, there are provided
releasing-lever holes 16 for inserting the first brake-releasing lever 31 and the
second brake-releasing lever 41 respectively. It is structured so that during normal
ascent and descent of the elevator car 4, the first brake-releasing lever 31 and the
second brake-releasing lever 41 are both fixed to the side parts of the frame body
of the counterweight 10 by fixing cords 17, and, in the case where the levers 31 and
41 are to be actuated in an emergency, the fixing cords 17 are broken by appliance
of predetermined forces to the levers 31 and 41 and the fixation to the counterweight
10 is released.
[0024] Next , the motion of the braking device 20 of the hoisting machine 11 as structured
above will be explained.
[0025] Figure 3 is an elevation for explaining the motion of opening and closing of the
braking device in accordance with the first embodiment of the present invention.
[0026] In the case where the braking device 20 is operated and the hoisting machine 11 is
in a braked state, i.e. in the state where the electromagnet inside the casing 27
of the electromagnet is not excited, as shown in Figure 2, the brake arms 23 are braking
rotation of the brake drum 21 by pressing the brake shoes 22 to the brake drum 21
with the force of the brake springs 24. Here, normal ascent and descent of the elevator
car 4 is performed by release of the braking device 20, as described below. In Figure
3, it is shown that the plunger 28 is pressed downward by excitation of the electromagnet
inside the casing 27 of the electromagnet. As a result of this, the brake lever 26,
which abuts on the plunger head 28a, pivots by being pressed by the plunger head 28a
with the brake lever pin 26a as its center; and the force of the plunger 28 is amplified
and transmitted to the brake arms 23 via the bolt 25. The brake arm 23 pivots against
the force of the brake springs 23 with the brake arm pins 23a as their centers, and
releases brake of the braking device 20 by separating the brake shoes 22 from the
brake drum 21. During normal ascent and descent of the elevator car 4, the first brake-releasing
lever 31 and the second brake-releasing lever 41 travel synchronously with the travel
of the counterweight 10. For this reason, the operation ropes 33 and 43 and the pulleys
32 and 42 which are constantly fixed to the levers 31 and 41 move synchronously with
the travel of the levers 31 and 41.
[0027] Next, the motion of the brake-releasing mechanism of the braking device 20 will be
explained.
[0028] Figure 4 is an elevation for explaining the motion of the first brake-releasing mechanism
in accordance with the first embodiment of the present invention.
[0029] In Figure 4, it is shown that the first brake-releasing mechanism 30 releases the
braking device 20 by actuating the first brake-releasing lever 31 by pulling down
the part of the rope which is at the side opposite to the part of the first operation
rope 33 where the first brake-releasing lever 31 is fixed. By pulling the first operation
rope 33 as aforementioned, the pulley 32 rotates in the direction shown by the arrow
in Figure 4, and the connection part of the first brake-releasing lever 31 and the
first operation rope 33 is pulled up. According to this, the first brake-releasing
lever 31 pivots with the supporting point supported by the supporting-point base 29
of the casing 27 of the electromagnet as the center, and the first releasing-lever
coupling part 34 presses the plunger head 28a downward. The subsequent motion is the
same as the brake releasing motion of the braking device 20; the force of the plunger
28 is transmitted to the brake arms 23 via the brake levers 26, and releasing of brake
of the braking device 20 is performed by resisting the brake springs 24. When actuating
the first brake-releasing lever 31, the fixing cord 17 which fixes the first brake-releasing
lever 31 to the counterweight 10 is broken, and operation of the first brake-releasing
lever 31 becomes possible by pulling the first operation rope 33.
[0030] Figure 5 is an elevation for explaining the motion of the second brake-releasing
mechanism in accordance with the first embodiment of the present invention.
[0031] In Figure 5, it is shown that the second brake-releasing mechanism 40 releases the
braking device 20 by actuating the second brake-releasing lever 41 by pulling down
the part of the rope which is at the side of the second operation rope 43 onto which
the second brake-releasing lever 41 is fixed. By pulling the second operation rope
43 as aforementioned, the connection part of the second brake-releasing lever 41 and
the second operation rope 43 is pulled down. According to this, the second pulley
42 rotates in the direction shown by the arrow in Figure 5. In accordance with this,
the second brake-releasing lever 41 pivots with the end part of the second brake-releasing
lever 41 which abuts on the supporting-point base 29 of the casing 27 of the electromagnet
as the supporting point, and the second brake-releasing lever coupling part 44 presses
the plunger head 28a downward. The subsequent motion is the same as the normal brake
releasing motion of the braking device 20 and the first brake-releasing mechanism
30; the force of the plunger 28 is transmitted to the brake arms 23 via the brake
levers 26, and releasing of brake is performed by resisting the brake springs 24.
When actuating the second brake-releasing lever 41, the fixing cord 17, which fixes
the second brake-releasing lever 41 to the counterweight 10, is broken, and operation
of the second brake-releasing lever 41 becomes possible by pulling the second operation
rope 43.
[0032] Next, the cases where each of the first brake-releasing mechanism 30 and the second
brake-releasing mechanism 40 are actually used will be explained.
[0033] In the case where the counterweight 10, onto which the braking device 20 is mounted,
is heavier than the elevator car 4, the first brake-releasing mechanism 30 is selected;
and releasing of brake of the braking device 20 is performed by usage of the first
brake-releasing lever 31. Inversely, in the case where the counterweight 10 is lighter
than the elevator car 4, releasing of brake of the braking device 20 is performed
by usage of the second brake-releasing lever 41.
[0034] Normally, depending on the imbalance between the counterweight 10 and the elevator
car 4 according to the change in the number of passengers embarking and disembarking
the elevator car 4, cases where the counterweight 10 becomes heavier than the elevator
car 4, and inversely, cases where the counterweight 10 becomes lighter than the elevator
car, 4 occur. For this reason, when the brake of the braking device 20 is released,
cases where the counterweight 10 moves up, and where the counterweight 10 moves down
occur, depending on the situation of the number of passengers.
[0035] The first brake-releasing lever 31 is used in cases where the counterweight 10 is
heavier than the elevator car 4, i.e. in cases where the counterweight 10 moves downward
when the braking device 20 is released. Here, if the first brake-releasing lever 31
is actuated, an upward force resisting the force of the lever 31 pressing the plunger
head 28a is exerted to the supporting-point base 29, which supports the supporting
point of the lever 31. For this reason, in cases where the counterweight 10 is lighter
than the elevator car 4, i.e. in cases where the counterweight 10 moves upward when
the braking device 20 is released, if the first brake-releasing lever 31 is used,
the pressing force to be exerted to the plunger head 28a by the first brake-releasing
lever 31 escapes because the counterweight 10 moves upward, which is the same as the
force exerted to the supporting-point base 29, and cases where releasing of brake
of the braking device 20 cannot be performed accurately occur.
[0036] Furthermore, the cases where the second brake-releasing lever 41 is to be used are
cases where the counterweight 10 is lighter than the elevator car 4, i.e. cases where
the counterweight 10 moves upward when the braking device 20 is released, as aforementioned.
Inversely to these cases, if the second brake-releasing lever 41 is used when the
counterweight 10 moves downward when the braking device 20 is released, the lever
41 acts with the end part of the brake lever 41 abutting on the supporting-point base
29 as the supporting point so as to press the plunger head 28a that is coupled with
a middle part of the lever 41, however, at this time, if the counterweight 10 moves
downward, the force of the lever 41 to press the plunger head 28a escapes, and cases
where releasing of brake of the braking device 20 cannot be performed accurately occur.
[0037] Accordingly, which of the first or the second brake-releasing mechanisms to use is
selected as mentioned above, depending on the situation of the number of passengers
in the elevator car 4.
[0038] Next: the first pulley 32 and the second pulley 42 used in the brake-releasing mechanism
of the braking device 20 of the hoisting machine 10 in accordance with the first embodiment
of the present invention are of iron; however, these can also be of synthetic resin,
which is lighter in weight. Furthermore, the first operation rope 33 and the second
operation rope 43 can be of synthetic fiber, which is lighter in weight compared to
those of iron. If the moments of inertia of the pulleys and the operation ropes are
large, the forces exerted by the operation ropes on the brake-releasing levers, which
move synchronously with the counterweight 10 also become large during normal acceleration
and deceleration of the elevator, thus causing disturbance upon the brake-releasing
mechanism. For this reason, it is possible to lessen the possibility of faulty operation
of the brake-releasing mechanism by using synthetic-resin pulleys and synthetic-fiber
operation ropes, and making them lighter in weight compared to those of iron.
[0039] According to the aforementioned first embodiment, the following effects can be obtained:
[0040] Since the braking device 20, which is mounted on the counterweight 10 with the hoisting
machine 11, has brake-releasing mechanisms that comprise a brake-releasing lever,
an operation rope and a pair of pulleys, in the event that electrical control to release
brake of the braking device 20 becomes impossible in an emergency, it is possible
to mechanically release brake of the braking device 20 from the ground, and there
is no necessity for a maintenance worker to go to the place where the hoisting machine
11 mounted on the counterweight has stopped to release brake of the braking device
20; thus it is possible to rescue passengers by moving the elevator car 4 to the nearest
floor with facility and without fail.
[0041] Also, as the brake-releasing mechanism is comprised of two sets - a first and a second
- brake-releasing mechanisms, in both the cases where the counterweight 10 is heavier
than the elevator car 4 and where it is lighter than the elevator car 4, it is possible
to select and use the brake-releasing mechanism suitable for the case, and it is possible
to release brake of the brake-releasing device 20 stably without being affected by
the imbalance between the weights of the counterweight 10 and the elevator car 4.
[0042] Furthermore, the first brake-releasing lever 31 and the second brake-releasing lever
41 both use a part of the casing 27 of the electromagnet as a supporting-point base
29 and make it work as a supporting point; the supporting-point base 29 is close to
the plunger head 28a that is the working point, and is preferable in position as a
supporting point. Moreover, the casing 27 of the electromagnet and the frame body
14 of the counterweight 10 are strongly-structured by nature and also high in strength,
so it is suitable for a supporting point.
[0043] Moreover, at normal ascent and descent of the elevator car 4, since the first brake-releasing
lever 31 and the second brake-releasing lever 41 are both fixed to the counterweight
10 by means of the fixing cord 17, it is possible to control impact of disturbance
caused by moments of inertia of the pulleys and the operation ropes.
Second Embodiment
[0044] Figure 6 is an elevation for explaining the structure of the brake-releasing mechanism
of the braking device in accordance with the second embodiment of the present invention.
[0045] As shown in Figure 6, in the second embodiment of the present invention, in the connection
part of the first brake-releasing lever 31 and the first operation rope 33, and the
connection part of the second brake-releasing lever 41 and the second operation rope
43, there are provided pierced holes (not shown) respectively on the lever sides thereof.
The operation ropes are passed through each of the pierced holes; the levers and the
operation ropes are not in contact with each other, so the operation ropes do not
move synchronously with the brake-releasing levers during normal ascent and descent
of the elevator car 4, inversely to the first embodiment. Accordingly, in the first
embodiment the counterweight 10 and the brake-releasing levers are fixed by means
of a fixing cord 17, however in the second embodiment, a fixing cord 17 is not used.
[0046] As a connecting means for connecting the brake-releasing levers and the operation
ropes in the cases where a brake-releasing mechanism is to be used, actuating pieces
18 are fixed on both the first operation rope 33 and the second operation rope 43.
Normally, the actuating piece 18 fixed on the side of the first operation rope 33
is arranged near the first pulley 32 provided in a lower part of the hoistway 1, and
the actuating piece 18 fixed on the side of the second operation rope 43 is arranged
near the second pulley 42 provided in an upper part of the hoistway 1. In the cases
where the brake-releasing mechanisms are actually operated, the levers and the actuating
pieces 18 become coupled by operating and moving each of the operation ropes in the
direction the levers are to be moved respectively, thus enabling operation of the
levers. The other structures and the motions are the same as the first embodiment,
so the same numerals are given to the same parts or the corresponding parts, thus
repeated explanation will be omitted.
[0047] According to the aforementioned first embodiment, the following effects can be obtained:
[0048] In the second embodiment, actuating pieces 18 are needed because the brake-releasing
levers and the operation ropes are not constantly fixed, however, as the brake-releasing
levers and the operation ropes are not in contact with each other during normal ascent
and descent of the elevator car 4, it is advantageous in the point that there is no
impact caused by moments of inertia from the pulleys nor from the operation ropes.
In addition to this, the same effects as the first embodiment can be attained.
[0049] In the above-mentioned embodiments, an elevator system in accordance with the present
invention wherein the hoisting machine 11 is mounted on the counterweight 10 has been
explained as an example, however, this can also be similarly applied to cases in which
the hoisting machine 11 is mounted on the elevator car 4.
Industrial Applicability
[0050] As aforementioned, the elevator system in accordance with the present invention enables
rescue of passengers by the maintenance worker's releasing brake of the braking device
from the ground mechanically and moving the elevator car to the nearest floor, in
the event that electric control of opening and closing of the braking device becomes
impossible when the elevator stops between floors due to malfunction. Also, as two
sets - a first and a second -brake-releasing mechanisms are comprised, it is possible
to perform a more stable releasing operation of the braking device with facility and
also without fail by selecting the brake-releasing device suited to the situation,
regardless of the number of passengers in the elevator car. Accordingly, the present
invention is useful as an elevator wherein security is improved in emergencies and
space-saving is aimed by mounting the hoisting machine on the elevator car or the
counterweight.
1. An elevator system
characterized in comprising:
an elevator car which travels through a hoistway;
a counterweight which travels through said hoistway in the direction opposite to said
elevator car;
a hoisting machine mounted on either of said elevator car or said counterweight;
a main rope wound around a drive sheave of said hoisting machine and suspending said
elevator car and said counterweight;
a braking device which is provided on said hoisting machine; which brakes said hoisting
machine by means of brake springs; and which releases brake of said hoisting machine
by resisting said brake springs by means of an excited electromagnet; and
a brake-releasing mechanism which is provided separately from said braking device,
and which releases brake of said braking device by mechanically resisting said brake
springs.
2. The elevator system according to claim 1,
characterized in that said brake-releasing mechanism comprises:
brake-releasing levers for retracting said brake springs and releasing brake of said
braking device;
operation ropes which are wound around a pair of pulleys that are each arranged in
a part higher and lower than the travel area of either of said elevator car or said
counterweight, and which are stretched in a loop shape, for operating said brake-releasing
levers; and
connection means for connecting said brake-releasing levers with said operation ropes.
3. The elevator system according to claim 2, characterized in that a supporting point of said brake-releasing levers is supported by a casing of an
electromagnet fixed on said elevator car or a frame of said counterweight.
4. The elevator system according to claim 2,
characterized in that said brake-releasing mechanism comprises a first and second set of brake-releasing
mechanisms, and in comprising:
a first brake-releasing mechanism comprising a pair of first pulleys, a first operation
rope and a first brake-releasing lever, wherein brake of said braking device is released
by pulling up said first operation rope; and
a second brake-releasing mechanism comprising a pair of second pulleys, a second operation
rope and a second brake-releasing lever, wherein brake of said braking device is released
by pulling down said second operation rope.
5. The elevator system according to claim 4,
characterized in that:
both of said first and second brake-releasing levers use as a supporting point thereof
said casing of electromagnet; said first brake-releasing lever has a first releasing-lever
supporting point thereof supported by said casing of electromagnet; and
said second brake-releasing lever has a second releasing-lever supporting point thereof
abutted on said casing of electromagnet.
6. The elevator system according to claim 4 or claim 5,
characterized in that:
said braking device is comprised so as to release brake of said hoisting machine by
resisting said brake springs, by drive of a pushing body by an excited electromagnet;
said first and second brake-releasing levers each have a first releasing-lever coupling
part and a second releasing-lever coupling part respectively which couple with said
pushing body; and
brake of said braking device is released by drive of said pushing body by said first
brake-releasing coupling part or said second brake-releasing coupling part.
7. The elevator system according to claim 6,
characterized in that:
said first brake-releasing coupling part is coupled with said pushing body with said
pushing body passed through a through hole provided on said first brake-releasing
lever; and
said second brake-releasing coupling part is rotatably connected with said pushing
body.
8. The elevator system according to any one of claims 2 through 7, characterized in that said pulleys are of synthetic resin and said operation ropes are of synthetic fiber.
9. The elevator system according to any one of claims 2 through 8, characterized in comprising fixing means for maintaining said brake-releasing levers in a state fixed
to said elevator car or said frame body of counterweight at normal travel of said
elevator car, and for releasing fixation of said brake-releasing levers by exertion
of a predetermined force to said operation ropes in the case where said brake-releasing
levers are to be actuated by said operation ropes.