[0001] The present disclosure relates to a damper for connecting a fall arrest device to
an elevator car, and further relates to an elevator system having a damper connecting
a fall arrest device to an elevator car and methods for operating and retrofitting
elevator systems.
BACKGROUND
[0002] Modern wind turbines are commonly used to supply electricity into the electrical
grid. Wind turbines generally comprise a rotor mounted on top of a wind turbine tower,
the rotor having a rotor hub and a plurality of blades. The rotor is set into rotation
under the influence of the wind on the blades. The operation of the generator produces
the electricity to be supplied into the electrical grid.
[0003] When maintenance works are required inside wind turbines, hoists are often used in
the form of elevator-like structures where a lift platform or a cabin for the transportation
of people and/or equipment is hoisted up and/or down within the wind turbine tower.
Wind turbines are often provided with working platforms arranged at various heights
along the height of the tower with the purpose of allowing workers to leave the cabin
and inspect or repair equipment where intended.
[0004] Elevator systems, in general, include an elevator car being suspended within a hoistway
or elevator shaft by wire ropes. The term wire rope is herein used to denote a relatively
thick cable. But in the art, the terms cables and wire ropes are often used interchangeably.
In some systems, e.g. for some electric elevators, a counterweight may be provided
depending on e.g. the available space. Other systems such as hydraulic elevators normally
do not comprise a counterweight.
[0005] The service elevators may incorporate some form of traction device mounted on or
attached to the elevator. The traction device may comprise a housing including a traction
mechanism, e.g. a motor driven traction sheave. The motor typically may be an electrical
motor, although in principle other motors could be used.
[0006] Service elevators further may incorporate an electromagnetic brake. In addition to
this brake, a "secondary safety device" or "fall arrest device" are rigidly mounted
on or attached to the elevator car, directly or through supporting structures. Such
a fall arrest device serves as a back-up for the main electromagnetic brake and may
typically incorporate some form of sensing mechanism sensing the elevator's speed.
The secondary safety device may automatically block the elevator and inhibit any further
movement if the elevator moves too fast, i.e. when the elevator might be falling.
The speed detection mechanism in this sense acts as an overspeed detector.
[0007] A hoisting wire rope of the service elevator or a dedicated safety wire rope may
pass through an entry hole in the safety device, through the interior of the safety
device and exit the safety device through an exit hole at an opposite end. Some form
of clamping mechanism for clamping the hoisting wire rope or the safety wire rope
when an unsafe condition exists (i.e. when the overspeed detector trips) may be incorporated
in the safety device.
[0008] Fall arrest devices, when fitted to an appropriate wire rope, can be of the type
that comprises internal rollers and a clamping mechanism (e.g. involving clamping
jaws) which closes onto the safety wire rope, which could be the main hoisting wire
rope or a separate safety wire rope. These devices may comprise a centrifugal overspeed
detector.
[0009] Such an overspeed detector may be provided on the inside of the housing of the fall
arrester device and may comprise a driven roller coupled with movable parts that are
forced outwardly as the roller rotates when it is driven by the wire rope passing
along it. A pressure roller ensures the contact between the wire rope and the driven
roller of the centrifugal overspeed detector. If the wire rope passes through the
safety device too rapidly, the brake trips and the jaws clamp onto the wire, thus
blocking the safety device on the wire rope by the frictional pressure exerted by
the clamping jaws onto the wire.
[0010] This frictional pressure for quickly blocking the safety device may generate a great
amount of energy that needs to be dissipated to avoid an excessive overheating of
the safety device components and of the wire rope. This overheating may lead to a
loss of tolerances of the clamping jaws and the wire rope and therefore to a loss
of the control of the pressure exerted by the clamping jaws during blocking the safety
device. Furthermore, blocking the safety device has to be fast enough for adequately
stopping the elevator car when an overspeed is detected, but relatively slow for not
abruptly stopping the elevator which may injure the users.
[0011] Controlling the pressure exerted by the clamping jaws during blocking may produce
a more progressive stopping of the elevator car. This pressure may be controlled by
e.g. dampers provided between the clamping jaws and the actuator of the safety device.
The dampers provided in the safety device may be able to partially absorb a part of
the energy created during braking the elevator car. In order to enhance the dampening
effect of the safety device, bigger and more powerful dampers may be provided in the
fall arrest device. However, this may imply a heavier and bigger fall arrest device
arranged on an elevator car which may have dimensional restrictions. Furthermore,
this heavier fall arrest may represent heavier elevator structures which may also
affect the structural behavior of e.g. the wind turbine tower.
[0012] In addition, the dampening effect provided by the fall arrest device, even using
powerful dampers arranged as part of the fall arrest device between the attachment
point to the car and the clamping jaws or brake calipers, may be insufficient to absorb
the energy generated in an emergency braking for safely stopping the elevator car,
e.g. stopping the elevator car relatively smoothly.
[0013] The present disclosure provides examples of systems and methods that at least partially
resolve some of the aforementioned disadvantages.
[0014] Service elevators and related safety devices such as fall arrest devices are not
only used in wind turbine towers, but instead may be found in many different sites
and structures.
SUMMARY
[0015] In a first aspect, a damper for connecting an elevator car and a fall arrest device
is provided. The damper comprises a deformable element with a first joining portion
configured to connect to the elevator car and a second joining portion configured
to connect to the fall arrest device. The deformable element of the damper is configured
to deform from an undeformed state to a deformed state in the event of a force above
a predetermined threshold force. The deformable element is further configured in such
a way that when the deformable element is deformed from an undeformed state to a deformed
state, the elevator car and the fall arrest device are relatively displaced.
[0016] In this aspect, the deformation of the deformable element absorbs at least partially
the energy generated in the event of a force above a predetermined threshold acting
on the damper. The damper according to the invention provides therefore an enhanced
dampening effect of the elevator car in the event of an emergency braking.
[0017] The force above a predetermined threshold force may be a blocking force opposite
to the descending force of the elevator car. This blocking force may be provided by
the fall arrest device, wherein the clamping system of the fall arrest device clamps
the safety wire of the elevator system. Such clamping system may be activated after
an overspeed has been detected by the overspeed detector. When an overspeed is detected,
the clamping system is activated and the fall arrest device is blocked. Such blocking
generates a blocking force which counteracts the descending force of the elevator
car. As the damper displaceably connects the elevator car and the fall arrest device,
when the fall arrest device is blocked the elevator car may still be displaced relatively
to the fall arrest device. Such relative displacement is controlled by the deformation
of the deformable element of the damper. The predetermined threshold force may be
the minimum force corresponding to the blocking force exerted by a fall arrest device
in the event of an emergency braking.
[0018] In an event of an emergency braking, the upward force of the fall arrest device counteracts
the downward force of the elevator. The upward force might be applied on the second
joining portion while the downward force on the first joining portion of the deformable
element. Such opposite forces deform the deformable element. The damper is therefore
able to compensate the upward force of the fall arrest device and the downward force
of the elevator car. This deformation absorbs at least partially the energy generated
when the fall arrest device is suddenly blocked, and thus the damper dampens the elevator
car when this is stopped. Furthermore, as the energy absorbed by the deformable element
increases with the relative displacement, such deformation allows to extend the blocking
time and to decrease the dynamic downward force of the elevator car.
[0019] The undeformed state of the deformable element corresponds to the shape of the deformable
element under a normal operation of the elevator, i.e. when the elevator is not stopped;
while the deformed state corresponds to the shape of the deformable element under
the effect of the activation of the fall arrest device, e.g. in an emergency braking.
[0020] The deformed state may comprise an elongated deformation or a bending deformation
or a compressed deformation, or a mixed of them, e.g. the deformable element may comprise
one elongated portion and one bending portion.
[0021] In some examples, the deformable element may be substantially extended when deformed
from the undeformed state to the deformed state. Such extension may comprise a substantial
axially elongation and/or a substantial bending of the deformable element or any combination
of them. The overall distance between the first joining and the second joining portion
of the deformable element may be therefore increased. The first joining portion may
be connected to the elevator while the second joining portion to the fall arrest device.
[0022] The deformable element may be configured in such a way than in the event of a force
above a predetermined threshold force, e.g. the blocking force from the fall arrest
device, the deformable element is stretched out from the undeformed state to a deformed
state. As the elevator car and the fall arrest device may be displaceably connected
through the damper, a relatively movement between the elevator car and the fall arrest
device is enabled. When the damper displaceably connects the elevator car and the
fall arrest device, the first joining portion may correspond to a lower vertical position
with respect to the second joining position. In the event of an emergency braking,
the fall arrest is blocked and the elevator car tends to continue descending, and
as the damper enables the relatively displacement of the elevator car and the fall
arrest device, the elevator car and the fall arrest device may be thus vertically
moved away.
[0023] Such separation may be controlled by the deformation of the deformable element of
the damper. In these examples, the distance between the elevator car and the fall
arrest device is increased and the deformable element is therefore substantially lengthened.
Thus, in these examples, the distance between the first and the second joining portion
of the deformable element is higher in the deformed state than in the undeformed state.
The deformable element is thus elongated from the undeformed state to the deformed
state.
[0024] In other examples, the deformable element may be substantially compressed when deformed
from the undeformed state to the deformed state. Such compression may comprise a substantial
axial compression and/or a substantial bending and/or buckling of the deformable element
or any combination of them, e.g. axially compressed by the inwardly and outwardly
bending of the lateral walls of the deformable element. The overall distance between
the first joining and the second joining portion may be thus reduced. The first joining
portion may be connected to the elevator while the second joining portion is connected
to the fall arrest device.
[0025] The deformable element may be configured in such a way that in the event of a force
above a predetermined threshold force, e.g. the blocking force from the fall arrest
device, the deformable element is compressed from the undeformed state to a deformed
state. As the elevator car and the fall arrest device may be displaceably connected
through the damper, a relative movement between the elevator car and the fall arrest
device is enabled. In these examples, when the damper displaceably connects the elevator
car and the fall arrest device, the first joining portion (associated with the elevator
car) may correspond to a higher vertical position with respect to the second joining
position (associated with the fall arrest). In the event of an emergency braking,
the fall arrest is blocked and the elevator car tends to continue descending, and
as the damper enables the relative displacement of the elevator car and the fall arrest
device, the elevator car and the fall arrest device may be therefore vertically approached.
[0026] Such approach may be controlled by the deformation of the deformable element of the
damper. In these examples, the distance between the elevator car and the fall arrest
device is reduced and the deformable element is therefore substantially shortened.
Thus, in these examples, the distance between the first and the second joining portion
of the deformable element is lower in the deformed state than in the undeformed state.
[0027] In some examples, the deformable element may comprise deformation initiators configured
to start and guide the deformation. These deformation initiators may be crush points,
bending initiators or buckling initiators. In some examples, the deformation initiators
are configured to act substantially like hinges. The deformation initiators may be
for example in the form of notches, weaker areas, narrowing areas, thinner areas or
having a reduced width compared to the width of the surrounding portions of the deformable
element.
[0028] In some examples, the deformable element is configured to elastically and plastically
deform in the event of a force above a predetermined threshold force. A plastic deformation
may increase the energy absorbed during stopping the elevator car. Furthermore, the
elevator car stopping time may be increased since the deformable elements may be firstly
elastically deformed and secondly plastically deformed. The dampening effect of the
damper can be enhanced in this way.
[0029] Additionally, the damper may further comprise a mounting plate. Such mounting plate
may comprise guides configured to displaceably connect the mounting plate to the first
joining portion of the deformable element. The mounting plate may be connected to
the first joining portion of the deformable element through the guides. Furthermore,
the mounting plate might be rigidly connected to the second joining portion of the
deformable element.
[0030] Such mounting plate may provide stiffness to the damper and may also limit the deformation
of the deformable element. In some examples, the mounting plate might act as a stopper
for the deformable element, in such a way that the deformation may be enclosed in
some certain limits.
[0031] In some examples, the guides of the mounting plate may be configured to displaceably
connect the mounting plate to the elevator car. The mounting plate may be configured
to be rigidly connected to the fall arrest device.
[0032] In a further aspect, an elevator system comprising an elevator car and a fall arrest
device and a damper according to any of the examples herein described is provided.
The fall arrest device may comprise an overspeed detector and a blocking system for
blocking the elevator car when an overspeed is detected by the overspeed detector.
In this aspect, the damper might connect the elevator car and the fall arrest device.
In a yet a further aspect, the present disclosure provides a wind turbine comprising
such an elevator system.
[0033] In yet a further aspect, a method for operating an elevator system according to any
of the examples disclosed herein is provided. The method comprises detecting an overspeed
by the overspeed detector, blocking the fall arrest device, e.g. by clamping the emergency
wire rope, and stopping the elevator car. The method further comprises deforming the
deformable element of the damper from an undeformed state to a deformed state in such
a way that fall arrest device and the elevator car are relatively displaced and the
elevator car is dampened.
[0034] In some examples, the method may further comprise measuring the speed of the elevator
car and activating the fall arrest device for blocking the elevator when the speed
of the elevator is an above a predetermined speed limit, e.g. when an overspeed has
been detected. The blocking of the elevator car may cause a force between the fall
arrest device and the elevator car above the predetermined threshold. Additionally,
the method may further comprise plastically deforming the deformable element of the
damper
[0035] In yet a further aspect, the present disclosure provides a method for retrofitting
an elevator system comprising an elevator car and a fall arrest device, the elevator
car and the fall arrest device being rigidly connected. The method comprises disconnecting
the fall arrest device from the elevator car, providing a damper according to any
of the examples disclosed herein, connecting the first portion of the deformable element
to the elevator car and connecting the second portion of the deformable element to
the fall arrest device.
[0036] According to this aspect, existing elevator systems wherein the fall arrest device
and the elevator car are rigidly connected may be retrofitted and provided with the
additional functionality herein described as being displaceably connected.
[0037] Throughout the present description and claims, the elevator car may be any suitable
elevator car. The fall arrest device may be also any suitable fall arrest device.
Such fall arrest devices may be preferably configured to clamp the hoisting wire rope
safety wire rope when an unsafe condition exists. Fall arrest or safety devices may
comprise internal rollers and a clamping mechanism for exerting pressure onto the
safety wire rope. Such fall arrest may further comprise an internal damper system
for controlling the pressure exerted by the clamping mechanism onto the safety wire
rope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Non-limiting examples of the present disclosure will be described in the following,
with reference to the appended drawings, in which:
Figures 1a - 1b schematically illustrate a view of an elevator system wherein a deformable
element of the damper is substantially extended from an undeformed state (fig. 1a)
to a deformed state (fig. 1b);
Figures 1c - 1d schematically illustrate a view of an elevator system wherein a deformable
element of the damper is substantially compressed from a undeformed state (fig. 1c)
to a deformed state (fig. 1d);
Figure 2 shows an example of a damper having a deformable element in the undeformed
state;
Figure 3 shows the damper of the figure 2 having a deformable element in the deformed
state;
Figure 4 shows an example of a damper including a mounting plate and at least one
deformable element in an undeformed state; and
Figure 5 shows an example of a damper including a mounting plate and at least one
deformable element in a deformed state; and
Figure 6 shows an isometric partial view of an example of an elevator system including
an elevator car, a fall arrest device and a damper.
Figure 7 shows the frontal partial view of the example of the elevator system of the
figure 6.
DETAILED DESCRIPTION OF EXAMPLES
[0039] In these figures the same reference signs have been used to designate matching elements.
[0040] Figures 1a - 1d schematically illustrate a view of an example of an elevator system
10. The elevator system 10 may comprise an elevator car 20, a safety wire 30, a fall
arrest device 40 and a damper 100 for connecting the elevator car 20 to the fall arrest
device 40. In these examples, the fall arrest device is illustrated for clarity purposes
on the back of the elevator car; however other arrangements as e.g. arranged on the
top of the elevator car and/or inside the elevator car are also possible. The damper
100 comprises a deformable element 110. In figure 1a and 1c the deformable element
110 is in an undeformed state P1, i.e. under a normal operation of the elevator, while
in figure 1b and 1d is in the deformed position P2, i.e. in after emergency braking.
[0041] The deformable element 110 is therefore configured to deform from an undeformed state
P1 to a deformed state P2 in such a way than the elevator car 20 and the fall arrest
device 40 are relatively displaced. In these examples, the deformable element 110
may be in a non-deformed state in the undeformed state P1 and in deformed state in
the deformed state P2.
[0042] Figure 1a and 1c represent the elevator system 10 under normal operation conditions
or the instant when the fall arrest device 40 is activated for stopping the elevator
car 20, but the elevator car 20 has not been yet stopped.
[0043] Figure 1b and 1d represent the elevator system 10 when the elevator car 20 is stopped
after the activation of the fall arrest device 40. The deformable element 110 is therefore
deformed from the undeformed state P1 (fig. 1 a and 1 c) to a deformed state P2 (fig.
1b and 1c), i.e. deformed from the instant when the fall arrest device is activated
to the stopping of the elevator car.
[0044] The fall arrest device 40 may comprise a blocking or a clamping system (not shown)
for clamping the safety wire 30 when an overspeed is detected by the overspeed detector
(not shown). When an overspeed is detected, the clamping system may be activated and
the fall arrest device 40 may be blocked. As the damper displaceably connects the
elevator car 10 and the fall arrest device 40, the elevator car 20 may be still displaced
relatively to the fall arrest device 40 although the fall arrest device may have been
blocked. Such relative displacement is controlled by the deformation of the deformable
element 110 of the damper 100.
[0045] The deformable element 110 of figures 1a - 1b may be substantially extended when
deforms from the undeformed state P1 to a deformed state P2. The deformable element
110 of these examples may be stretched out by the relative upward force of the blocking
of the fall arrest device 40 and the downward force of the elevator car 20 in such
a way that it may be substantially extended from the first to the deformed state.
The damper 100 enables that elevator car and the fall arrest device may be vertically
moved away. Such extension may comprise a substantial axially elongation and/or a
substantial bending of the deformable element 110 or any combination of them.
[0046] The deformable element 110 of figures 1c - 1d may be substantially compressed when
deforms from the undeformed state P1 to a deformed state P2. The deformable element
110 of these examples may be shortened by the relative upward force of the blocking
of the fall arrest device 40 and the downward force of the elevator car 20 in such
a way that the deformable element may be substantially compressed from the first to
the deformed state. The damper 100 enables that elevator car and the fall arrest device
may be vertically approached. Such compression may comprise a substantially axial
compression and/or a bending and/or buckling of the deformable element or any combination
of them.
[0047] Figure 2 illustrates an example of a damper 100 having a deformable element 110 in
the undeformed state P1. The damper 100 may be configured for displaceably connecting
an elevator car (not shown) and a fall arrest (not shown). The damper 100 comprises
a deformable element 110 with a first joining portion 111 configured to displaceably
connect to the elevator car and a second joining portion 121 configured to connect
the to the fall arrest device.
[0048] In this aspect, the deformable element 110 may further comprise a central portion
130 extending from the first joining portion 111 to the second joining portion 121.
[0049] In some examples the deformable element 110 may comprise a deformation initiator
140 configured to start and guide the deformation when a load is applied.
[0050] In some examples, the deformable element 110 may comprise a deformation initiator
140 arranged between the first joining portion 111 and the central portion 130. Alternatively,
the deformation initiator 140 may be arranged between the central portion 130 and
the second joining portion 121. In further other examples, the deformable element
110 may comprise one deformation initiator 140 arranged between the first joining
portion 111 and the central portion 130 and another one between the central portion
130 and the second joining portion 121.
[0051] In this aspect, deformation initiators 140 may be configured to act substantially
like hinges or bending initiators. Therefore, such deformation initiators 140 may
enable the rotation of the central portion 130 with respect to the first joining portion
111 and/or of the central portion 130 with respect to the second joining portion 121.
Alternatively, these deformation initiators may be crush points or buckling initiators.
[0052] In this aspect, the deformation initiators 140 may have a reduced width compared
to the width of the surrounding portions of the deformable element, i.e. a narrowing
area. In these examples, there is less resistive area in the deformation initiators
140 than in the remaining parts of the deformable element. As the resistive area is
smaller, the deformable element offers less resistance to be deformed in the narrow
areas than in the remaining parts. Therefore, when a force above a predetermined threshold
force is applied, e.g. in case of an emergency braking, the deformable element 110
may be deformed by the deformation initiators 140.
[0053] In this way, when the deformation initiator is arranged between the first joining
portion 111 and the central portion 130, the width of the deformation initiator 140
might be less than the width first joining portion 111 and the central portion 130.
Alternatively, when the deformation initiator is arranged between the central portion
130 and the second joining portion 121, the initiator 140 might have a reduced width
compared to the central portion 130 and to the second joining portion 121. Alternatively,
the deformation initiators 140 may be for example in the form of notches, weaker areas,
or thinner areas.
[0054] The central portion 130 and the first joining portion 111 may form an angle α. An
angle β may be formed between the central portion 130 and the second joining portion
121.
[0055] In some examples, the first joining portion 111 may further comprises a first end
112 and a second end 113. The central portion 130 may extend from the second end 113
in a direction substantially towards the first end 112 in such a way that the angle
α is an acute angle. When the deformable element 110 is in the undeformed state P1,
the central portion 130 may be folded substantially towards the first joining portion
111, and particularly towards the first end 112. The angle α may be in the range of
20° to 95°. Optionally, the angle α may be in the range of 45° to 85°.
[0056] In some examples, the second joining portion 121 may be substantially folded with
respect to the central portion 130, in such a way that the angle β may an acute angle,
e.g. in the range of 10° to 60°.
[0057] In some examples, the deformable element may have substantially swan's neck shape.
[0058] The deformable element 110 may be made by any suitable material able to be elastically
and/or plastically deformed when a force above a predetermined threshold force is
applied while maintaining a certain structural rigidity. In particular, the deformable
element might be a metal, and more particular aluminum. Other metals e.g. steel, might
be also suitable materials.
[0059] Figure 3 illustrates the damper of figure 2 having the deformable element 110 in
the deformed state P2. In these examples, the deformable element may be substantially
extended when it deforms from an undeformed state P1 (fig. 2) to a deformed state
P2 (fig. 3). Such an extension may comprise a substantially axial elongation and/or
a substantial bending or any combination of them. The overall distance between the
first joining 111 and the second joining portion 121 may be therefore increased.
[0060] In this aspect, when the deformable element 110 is in the deformed state P2, the
central portion 130 and the first joining portion 111 may form an angle α'. The central
portion 130 may be substantially unfolded towards the first joining portion 111. The
angle α' (associated with the deformed state) may be therefore higher than the angle
α (associated with the undeformed state). The angle α' might be in the range of 60°
to 120°.
[0061] Alternatively or additionally, the second joining portion 121 may be bent upwards
with respect to the central portion 130. The angle β' may be in the range of 30° to
150°.
[0062] The deformation of the deformable element 110, e.g. by allowing the rotation of central
portion 130 with respect to the first joining portion 111 and the second joining portion
121 with respect to the central portion 130 through the deformation initiators 140,
might enable absorbing at least partially the energy generated during the stopping
of the elevator.
[0063] Figure 4 shows an example of a damper 100 including a mounting plate 150 and at least
one deformable element 110 in the undeformed state P1.
[0064] In some examples, the damper 100 may comprise a mounting plate 150 and two deformable
elements 110.
[0065] Such mounting plate 150 may comprise guides 161 configured to displaceably connect
the mounting plate to the first joining portion of the deformable element 111. The
mounting plate 150 may be connected to the first joining portion of the deformable
element 111 through the guides 161. Furthermore, the mounting plate 150 might be rigidly
connected, e.g. bolted or fastened, to the second joining portion of the deformable
element 121.
[0066] Alternatively, the mounting plate 150 might be displaceably connected to the second
joining portion 121 of the deformable element 110 through the guides 161 and rigidly
connected to the first joining portion 121.
[0067] In some examples, the mounting plate 150 may comprise a left lateral portion 181,
right lateral portion 182 and a central body 183. The central body 183 may be connected
to the two second joining portions of the deformable elements. The left lateral portion
181 and the right lateral portion 182 may comprise the guide(s) 161.
[0068] The first joining portion 111 of one of the deformable element 110 may be displaceably
connected to the guide(s) of the mounting plate 161 arranged on the left lateral portion
of the mounting plate 181. The second joining portion 121 of this deformable element
110 may be rigidly connected to the central body 183 of the mounting plate.
[0069] The other deformable element may be arranged symmetrically as a mirror image. Therefore,
the first joining portion 111 of the other the deformable element may be displaceably
connected to the guide(s) of the mounting plate 161 arranged on the right lateral
portion of the mounting plate 182 and the second joining portion 121 of said another
deformable element 110 may be rigidly connected to the central body 183 of the mounting
plate.
[0070] In some examples, each of the right and left lateral portions may comprise a pair
of guides 161 associated to the corresponding first joining portion 111 of the deformable
elements 110.
[0071] Furthermore, the guides 161 may be configured to displaceably connect the mounting
plate to an elevator car (not shown) and the mounting plate 150, and in particular
the central body 183 of the mounting plate 150, may be configured to be rigidly connected
to a fall arrest device (not shown).
[0072] In some examples, the guides 161 may act like a retainer in such a way that the relative
displacement of the deformable elements 110 over the mounting plate 150 is limited.
Such guides 161 may be e.g. in the form of a slot vertically arranged.
[0073] In some examples, each of the deformable elements 110 may be connected to the mounting
plate 150 in similar way, and thus only the connection of one of the deformable elements
110 is described. The first joining portion of the deformable element 111 might be
bolted to the guide161 of the left lateral portion 181. Thus, the bolt (not shown)
connecting the mounting plate 150 to the first joining portion of the deformable element
111 may be displaced along the guide 161. Therefore, the first joining portion of
the deformable element 111 and the left lateral portion 181 of the mounting plate
150 may be displaceably connected, i.e. the deformable element 110 may slide over
the guide 150.
[0074] Instead of a bolt sliding on the guide or slot 161, other joining systems allowing
a relative displacement of the deformable element 110 with respect to the mounting
plate 150 may be alternatively used. Such relative displacement may allow guiding
the deformation of the deformable element 111. In these examples, the bolt may slide
on the mounting plate 150 from an upper position, i.e. the deformable element in the
undeformed state P1, to a lower position, i.e. the deformable element in the deformed
state P2.
[0075] In some examples, the mounting plate 150 may provide stiffness to the damper and
protect the deformable element 110. Furthermore, the mounting plate may limit the
deformation of the deformable element 110. The guide 161 may maintain the deformation
of the deformable element 110 under a controlled certain limits, i.e. enclosing the
deformable element. The guide 161, may retain the deformable element 110 joined to
the mounting plate 150 even when the deformable element has broken after an excessive
deformation. Therefore, the mounting plate 150 may act as a safety system since the
total disconnection of the deformable element 110 from the mounting plate 150 may
be avoided. Thus, when the deformable element 110 collapses, the mounting plate avoids
that deformable element 110 would fall.
[0076] The mounting plate 150 may be made by any suitable material able to provide enough
stiffness to the damper 100. In particular, the mounting plate might be a metal, and
in particular steel.
[0077] In some examples, such at least one deformable element 110 may be of any suitable
shape. In other examples, the deformable element 110 may be according to figure 2
and 3.
[0078] Figure 5 illustrates the damper of figure 4 having the deformable element 110 in
the deformed state P2.
[0079] In these examples, the deformable element may be substantially extended when deforms
from an undeformed state P1 to a deformed state P2. The deformation of the deformable
element 110 may be as previously explained in the examples according to figures 2
and 3.
[0080] Therefore, the overall distance between the first joining 111 and the second joining
portion 121 of said deformable elements may be therefore increased. As the first joining
portion 111 of each of the deformable elements may be displaceably connected to the
guides 161 of the mounting plate, the deformable element 110 may slide over the mounting
plate 150 when the deformable element is in a deformed state P2.
[0081] In some examples, the bolt (not shown) connecting the mounting plate 150 to the first
joining portion of the deformable 111 may be displaced along the guide 161 when the
deformable element is deformed from an undeformed state P1 to a deformed state P2.
In these examples, in a deformed state the bolt may be arranged on the guide or slot
161 in a substantially lower position compared to an upper position in an undeformed
state of the deformable element 110. Therefore, the first joining portion 111 of the
deformable element is moved away with respect to the second joining portion 121 of
the deformable element, i.e. the first joining portion 111 slides over the guide while
the second joining portion 121 is rigidly connected to the mounting plate 150.
[0082] Figure 6 and figure 7, a frontal view of the figure 6, show an example of an elevator
system 10 including an elevator car 20, a fall arrest device 40 and a damper 100.
The damper 100 may be according to figures 4 and 5.
[0083] The elevator system 10 may comprise an elevator car 20, a safety wire (not shown),
a fall arrest device 40 including an overspeed detector (not shown) and a damper 100
for displaceably connecting the elevator car 20 to the fall arrest device 40.
[0084] In some examples, the elevator system 10 may further comprise an elevator car structure
21 attached or forming part of to the elevator car. The elevator car structure 21
and the elevator car 20 may be thus moved together. Sometimes such elevator car structure
21 may be also called spine. Such elevator car structure 21 may be arranged on the
top portion of the elevator car 20. In some examples, the elevator car structure 21
may be a metallic plate.
[0085] In some examples, the fall arrest device 40 may further comprise a housing bracket
41 for mounting the fall arrest device to the damper. Such housing bracket 41 may
be attached or forming part to the fall arrest device. The housing bracket 41 and
the fall arrest device 40 may be rigidly connected, i.e. are moved together.
[0086] In some examples, the housing bracket 41 may be U-shaped. In this aspect, the U-shaped
housing bracket may further comprise two lateral sides arranged on each side of the
U-shape. Such lateral sides may be connected to the damper, in particular to central
portion 183 of the mounting plate 150 and/or to the second joining portion of the
deformable elements 121. The bottom part of the U-shape may be connected to the fall
arrest device 140.
[0087] In some examples, the fall arrest device 40 and the damper 10 might be arranged inside
the elevator car, and in particular on the top portion of the elevator car.
[0088] In some examples, the first joining portion 111 of the deformable element of the
damper may be rigidly connected to elevator car 20, directly or through the elevator
car structure 21, while the mounting plate 150 may be displaceably connected to the
elevator car 20. The second joining portion 121 of the deformable elements may be
rigidly connected to the fall arrest device 40, directly or through the bracket housing
41.
[0089] In this aspect, the mounting plate 150 may be displaceably connected to the elevator
car 20 through the guides 161. The mounting plate may be rigidly connected to the
fall arrest device 40. The mounting plate 150 may be directly connected to the elevator
car 20 and/or to the fall arrest device or through an elevator car structure 21 and/or
through the bracket of the fall arrest device.
[0090] In these examples, the deformable elements may be substantially extended when deforms
from an undeformed state P1 to a deformed state P2. The deformation of the deformable
elements 110 may be as previously explained in the examples according to figures 2
and 3.
[0091] Therefore, the overall distance between the first joining 111 and the second joining
portion 121 of said deformable elements may be thus increased.
[0092] As the first joining portion 111 of each of the deformable elements may be displaceably
connected to the mounting plate through the guides 161 and rigidly connected to the
elevator car 20 (or to the elevator car structure 21), the deformable element 110
and the elevator car 20 may slide over the mounting plate 150 when the deformable
element is in a deformed state P2. Since the fall arrest device 40 (or the housing
bracket 41) may be rigidly connected to the mounting plate, the elevator car 20 and
the fall arrest device may be relatively displaced when the deformable element 110
is deformed from an undeformed state P1 to a deformed state P2.
[0093] In some examples, the bolt(s) connecting first joining portion of the deformable
element 111 to the guide(s) 161 of the mounting plate may also connect the elevator
car 20 to the mounting plate 150 and to the deformable element 110. The bolt(s) may
be displaced along the guide(s) 161, e.g. in the form of a vertical slot, when the
deformable element is deformed from an undeformed state P1 to a deformed state P2.
Therefore, the first joining portion 111 of the deformable element and the elevator
car are moved away with respect to the second joining portion 121 of the deformable
element and the mounting plate. In other words, when the deformable element is extended,
the elevator car is relatively moved away with respect to the fall arrest device.
[0094] Despite the deformation of the deformable element, the displacement of the elevator
car with respect to the fall arrest device may be restricted by the guides. Such displacement
restriction may work similarly as described in figures 4 and 5. In these examples,
such guide(s) 161 may retain the elevator car 20 connected to the fall arrest device
40 (and thus to the mounting plate 150) even when the deformable element 110 is broken
after an excessive deformation. Therefore, the mounting plate 150 may act as a safety
system since the entire disconnection of the elevator car 20 to the fall arrest device
may be avoided. Thus, when the deformable element 110 collapses, the mounting plate
150 holds the elevator car.
[0095] In other examples, the damper 100 may be according to any of the examples herein
described.
[0096] Although only a number of examples have been disclosed herein, other alternatives,
modifications, uses and/or equivalents thereof are possible. Furthermore, all possible
combinations of the described examples are also covered. Thus, the scope of the present
disclosure should not be limited by particular examples, but should be determined
only by a fair reading of the claims that follow. If reference signs related to drawings
are placed in parentheses in a claim, they are solely for attempting to increase the
intelligibility of the claim, and shall not be construed as limiting the scope of
the claim.
1. A damper for connecting an elevator car and a fall arrest device, the damper comprising:
a deformable element having:
a first joining portion configured to connect to the elevator car;
a second joining portion configured to connect to the fall arrest device;
wherein
the deformable element is configured to deform from an undeformed state to a deformed
state in the event of a force above a predetermined threshold force in such a way
that the elevator car and the fall arrest device are relatively displaced when the
deformable element is deformed
2. A damper according to claim 1, wherein the deformable element is compressed when it
is deformed from the undeformed state to the deformed state
3. A damper according to claim 1, wherein the deformable element is extended when it
is deformed from the undeformed state to the deformed state.
4. A damper according to any of claims 1-3, wherein the deformable element comprises:
a central portion extending from the first joining portion to the second joining portion;
deformation initiators configured to start and guide the deformation of the deformable
element; wherein
one deformation initiator is arranged between the first joining portion and the central
portion and another one between the second joining portion and the central portion.
5. A damper according to claim 4, wherein the central portion forms an angle an α with
the first joining portion and an angle β with the second joining portion; wherein
the angle α and the angle β are higher when the deformable element is in the deformed
state than when it is in the undeformed state.
6. A damper according to claim 4 or 5, wherein the deformation initiators are configured
to act substantially like hinges.
7. A damper according to any of claims 4 - 6, wherein the deformation initiators have
a reduced width compared to the width of the first joining portion, the central portion
and the second joining portion.
8. A damper according to any of claims 1 - 7, wherein the deformable element is configured
to plastically deform in the event of a force above the predetermined threshold.
9. A damper according to any of claims 1 - 8, wherein the damper comprises a mounting
plate, the mounting plate having:
guides configured to displaceably connect the mounting plate to the first joining
portion of the deformable element; wherein
the mounting plate is connected to the first joining portion of the deformable element
through the guides; and
the mounting plate is rigidly connected to the second portion of the deformable element.
10. A damper according to claim 9, wherein the guides of the mounting plate are further
configured to displaceably connect the mounting plate to the elevator car and the
mounting plate is further configured to be rigidly connected to the fall arrest device.
11. A damper according to any of claims 7 - 9, wherein the mounting plate comprises a
central body and a right lateral portion and a left lateral portion; and wherein
the right and left lateral portions comprise the guides; and wherein
the first joining portion of one of the deformable element is connected to the guides
of the right lateral portion, and the first joining portion of the other deformable
element is connected to the guides of the left lateral portion; and
the second joining portions of the deformable elements are rigidly connected to the
body of mounting plate.
12. An elevator system comprising:
an elevator car,
overspeed detector,
a fall arrest device comprising an overspeed detector and a blocking system for blocking
the elevator car when an overspeed is detected by the overspeed detector, and
a damper according to any of claims 1-11,
wherein the damper connects the elevator car and the fall arrest device.
13. An elevator system according to claim 12, wherein the elevator car further comprises
an elevator car structure connected to the damper; and wherein the fall arrest device
is connected to the damper by a housing bracket.
14. A method for operating an elevator system according to any of claims 12 - 13, the
method comprising:
detecting an overspeed by the overspeed detector,
blocking the fall arrest device
stopping the elevator car,
15. A method for retrofitting an elevator system comprising an elevator car and a fall
arrest device, the elevator car and the fall arrest being rigidly connected:
disconnecting the fall arrest device from the elevator car providing a damper according
to any of claims 1 - 11,
connecting the first portion of the deformable element to the elevator car,
and
connecting the second portion of the deformable element to the fall arrest device.