ELEVATOR SAFETY GEAR

Abstract

 An elevator safety gear (20) comprises an engagement member (26) with an engagement face (23) extending in a longitudinal direction and configured for engaging with a guide member (14, 15) of an elevator system (2), and an opposing actuated face (25), which is inclined with respect to the longitudinal direction; an actuator member (30) comprising an actuation face (31) facing the actuated face (25) of the engagement member (26) and being inclined with respect to the longitudinal direction; and a force transfer member (28) sandwiched between the engagement member (26) and the actuator member (30). The force transfer member (28) comprises a first face (27) extending parallel to the actuated face (25) of the engagement member (26) and a second face (29) extending parallel to the actuation face (31) of the actuator member (30).

Description

[0001] The invention relates to an elevator safety gear. The invention also relates to an elevator car and to an elevator counterweight respectively comprising an elevator safety gear. The invention further relates to an elevator system comprising such an elevator car and/or such a counterweight.

[0002] An elevator system typically comprises at least one elevator car moving along a hoistway extending between a plurality of landings, and a driving member configured for driving the elevator car. In particular embodiments, the elevator system may further include a counterweight moving concurrently and in opposite direction with respect to the elevator car. In order to ensure safe operation, the elevator system further comprises at least one safety gear ("elevator safety gear"). An elevator safety gear is configured for braking the movement of the elevator car and/or of the counterweight relative to a guide member, such as a guide rail, in an emergency situation, in particular when the movement of the elevator car and/or of the counterweight exceeds a predetermined velocity or acceleration.

[0003] It would be beneficial to provide an improved elevator safety gear which may be activated more easily.

[0004] According to an embodiment of the invention, an elevator safety gear comprises an engagement member, an actuator member, and a force transfer member. The force transfer member is arranged between the engagement member and the actuator member.

[0005] The engagement member is wedge-shaped including an engagement face and an opposing actuated face. The engagement face extends in a longitudinal direction, which is oriented parallel to a guide member of an elevator system, and is configured for engaging with said guide member. The actuated face is inclined with respect to the longitudinal direction.

[0006] The actuator member comprises an actuation face oriented towards the actuated face of the engagement member and being inclined with respect to the longitudinal direction.

[0007] The force transfer member is sandwiched between the engagement member and the actuator member. The force transfer member is also wedge-shaped comprising a first face extending parallel to the actuated face of the engagement member and a second face extending parallel to the actuation face of the actuator member.

[0008] In combination, the engagement member, the force transfer member and the actuator member constitute a mechanism amplifying an actuating force F_a applied to the actuator member using the lever effect and generating an engagement force Fb which is considerably larger than the actuating force F_a.

[0009] As a result, the elevator safety gear can be activated, i.e. the engagement member can be pressed against the guide member with an engagement force F_b, by applying a smaller actuating force F_a < Fb to the actuator member. In consequence, a relatively small actuator may be employed. Using a small actuator allows reducing the weight and the dimensions of the elevator safety gear.

[0010] The safety gears according to exemplary embodiments of the invention are of the self-braking type. Once actuated, the interaction of the engagement member, the force transfer member and the actuator member will cause a wedging effect. The wedging effect is driven by friction between the engagement member and the guide member.

[0011] Exemplary embodiments of the invention also include an elevator car comprising at least one elevator safety gear according to an exemplary embodiment of the invention.

[0012] Exemplary embodiments of the invention further include a counterweight for an elevator system comprising at least one elevator safety gear according to an exemplary embodiment of the invention.

[0013] Exemplary embodiments of the invention also include an elevator system comprising at least one elevator car according to an exemplary embodiment of the invention and/or at least one counterweight according to an exemplary embodiment of the invention.

[0014] Exemplary embodiments of the invention further include a method of actuating an elevator safety gear according to an exemplary embodiment of the invention, wherein the method includes exerting an actuating force onto the actuator element. The method in particular may include exerting the actuating force in the longitudinal direction, i.e. parallel to the guide member.

[0015] A number of optional features are set out in the following. These features may be realized in particular embodiments, alone or in combination with any of the other features, unless specified otherwise.

[0016] The first face of the force transfer member may abut against the actuated face of the engagement member and/or the second face of the force transfer member may abut against the actuation face of the actuator member also in an idle state, i.e. in a state in which the elevator safety gear is not activated. In a configuration in which the faces of the members abut against each other even in the idle state, no gaps between the members need to be closed before the engagement member moves. Thus, any movement of the actuator member directly and immediately results in a movement of the engagement member. In consequence, the time of engagement of the elevator safety gear is shorter than in a configuration in which the members do not abut against each other in the idle state.

[0017] The actuation face of the actuator member may be elastically movable in a direction transverse, in particular orthogonal, to the longitudinal direction. An elastically supported actuation face of the actuator member allows for a soft activation of the elevator safety gear. A soft activation of the elevator safety gear reduces the risk of injury for passengers within the elevator car. A soft activation of the elevator safety gear also reduces the risk of damaging components of the elevator system due to (too) large braking forces.

[0018] The actuation face of the actuator member in particular may be supported elastically by an appropriate elastic element, e.g. by a spiral spring or by an elastic element made of an elastic material including metal and/or plastic.

[0019] The force transfer member may be supported so that it is not able to move in the longitudinal direction. The force transfer member in particular may be supported so that it is movable only in a plane extending orthogonally to the longitudinal direction, i.e. orthogonally to the extension of the guide member. Such a configuration allows for a very efficient force transfer from the actuator member to the engagement member by the force transfer member.

[0020] The actuated face of the engagement member may be oriented at an angle α of 0° < α < 10°, particularly at an angle 2,5° < α < 7,5°, more particularly at an angle α of 5,4° with respect to the longitudinal direction / guide member.

[0021] The actuation face of the actuator member may be oriented at an angle β of 0° < β < 40°, particularly at an angle 15° < β < 30°, more particularly at an angle β of 20° with respect to the longitudinal direction / guide member.

[0022] Angles α and β in the mentioned ranges have been found as being particularly efficient for amplifying the actuating force applied to the actuator member.

[0023] The elevator safety gear may further comprise an actuator, e.g. an electric, mechanic, hydraulic, pneumatic actuator, which is configured for actuating the actuator element by exerting an actuating force onto the actuator element. The actuator in particular may be configured for applying an actuating force in the longitudinal direction.

[0024] As the actuating force applied by the actuator to the actuator member is amplified by the interaction of the actuator member, the force transfer member and the engagement member, a relatively small and light actuator may be used.

[0025] The actuator may be configured for moving the actuator element over a relatively small distance of 1 mm to 5 mm, in particular over a distance of 2 mm to 3 mm.

[0026] At least one of the actuation face, the actuated face, the first face and the second face may be provided with a low friction coefficient in order to reduce the friction between the engagement member, the force transfer member and the actuator member, respectively.

[0027] Said at least one face with a low friction coefficient in particular may be formed by applying a coating having a low friction coefficient to at least one face of at least one of the members.

[0028] Low friction between the members enhances the reliability and shortens the activation time of the elevator safety gear. It further reduces the actuating force needed for actuating the elevator safety gear.

[0029] In order to reduce the friction between the abutting faces of the members, a lubricant such as oil or grease may be applied to the first face of the force transfer member and the actuated face of the engagement member and/or to the second face of the force transfer member and the actuation face of the actuator member, respectively.

[0030] In the following, exemplary embodiments of the invention are described in more detail with respect to the enclosed figures:

Figure 1 schematically depicts an elevator system with an elevator safety gear according to an exemplary embodiment of the invention.

Figure 2 shows a perspective view of an elevator car comprising an elevator safety gear according to an exemplary embodiment of the invention.

Figure 3 shows a schematic sectional view of an elevator safety gear according to an exemplary embodiment of the invention.

Figure 4 shows a schematic sectional view of an elevator safety gear according to another exemplary embodiment of the invention.

[0031] Figure 1 schematically depicts an elevator system 2 according to an exemplary embodiment of the invention.

[0032] The elevator system 2 includes an elevator car 60 movably arranged within a hoistway 4 extending between a plurality of landings 8. The elevator car 60 in particular is movable along a plurality of car guide members 14, such as guide rails, extending along the longitudinal (vertical) direction of the hoistway 4. Only one of said car guide members 14 is visible in Figure 1.

[0033] Although only one elevator car 60 is depicted in Figure 1, the skilled person will understand that exemplary embodiments of the invention may include elevator systems 2 having a plurality of elevator cars 60 moving in one or more hoistways 4.

[0034] The elevator car 60 is movably suspended by means of a tension member 3. The tension member 3, for example a rope or belt, is connected to a drive unit 5, which is configured for driving the tension member 3 in order to move the elevator car 60 along the height of the hoistway 4 between the plurality of landings 8, which are located on different floors.

[0035] Each landing 8 is provided with a landing door 11, and the elevator car 60 is provided with a corresponding elevator car door 12 for allowing passengers to transfer between a landing 8 and the interior of the elevator car 60 when the elevator car 60 is positioned at the respective landing 8.

[0036] The exemplary embodiment shown in Figure 1 uses a 1:1 roping for suspending the elevator car 60. The skilled person, however, easily understands that the type of the roping is not essential for the invention and that different kinds of roping, e.g. a 2:1 roping or a 4:1 roping may be used as well.

[0037] The elevator system 2 includes further a counterweight 19 attached to the tension member 3 and moving concurrently and in opposite direction with respect to the elevator car 6 along at least one counterweight guide member 15. The skilled person will understand that the invention may be applied also to elevator systems 2 which do not comprise a counterweight 19.

[0038] The tension member 3 may be a rope, e.g. a steel wire rope, or a belt. The tension member 3 may be uncoated or may have a coating, e.g. in the form of a polymer jacket. In a particular embodiment, the tension member 3 may be a belt comprising a plurality of polymer coated steel cords (not shown). The elevator system 2 may have a traction drive including a traction sheave for driving the tension member 3. In an alternative configuration, which is not shown in the figures, the elevator system 2 may be an elevator system 2 without a tension member 103, comprising e.g. a hydraulic drive or a linear drive. The elevator system 2 may have a machine room (not shown) or may be a machine room-less elevator system.

[0039] The drive unit 5 is controlled by an elevator control unit (not shown) for moving the elevator car 60 along the hoistway 4 between the different landings 8.

[0040] Input to the control unit may be provided via landing control panels 7a, which are provided on each landing 8 close to the landing doors 11, and/or via an elevator car control panel 7b, which is provided inside the elevator car 60.

[0041] The landing control panels 7a and the elevator car control panel 7b may be connected to the elevator control unit by means of electric wires, which are not shown in Figure 1, in particular by an electric bus, or by means of wireless data connections.

[0042] The elevator car 60 is equipped with at least one elevator safety gear 20, which is schematically illustrated at the elevator car 60. Alternatively or additionally, the counterweight 19 may be equipped with at least one elevator safety gear 20. An elevator safety gear 20 attached to the counterweight 19, however, is not shown in Figure 1.

[0043] The elevator safety gear 20 is operable to brake or at least assist in braking (i.e. slowing or stopping the movement) of the elevator car 60 relative to a car guide member 14 by engaging with the car guide member 14. In the following, the structure and the operating principle of an elevator safety gear 20 according to an exemplary embodiment of the invention will be described.

[0044] Figure 2 is an enlarged perspective view of an elevator car 60 according to an exemplary embodiment of the invention. The elevator car 60 comprises a structural frame comprising vertically extending uprights 61 and crossbars 63 extending horizontally between the uprights 61. Only one upright 61 is visible in Figure 2.

[0045] The elevator car 60 further includes a car roof 62, a car floor 64 and a plurality of car side walls 66. In combination, the car roof 62, the car floor 64 and the plurality of side walls 66 define an interior space 68 for accommodating and carrying passengers 70 and/or cargo (not shown).

[0046] An elevator safety gear 20 according to an exemplary embodiment of the invention is attached to an upright 61 of the elevator car 60.

[0047] Although only one elevator safety gear 20 is depicted in Figures 1 and 2, respectively, the skilled person will understand that a plurality of safety gears 20 may be mounted to a single elevator car 60. In particular, in a configuration in which the elevator system 2 comprises a plurality of car guide members 14, an elevator safety gear 20 may be associated with each car guide member 14.

[0048] Alternatively or additionally, two or more elevator safety gears 20 may be provided on top of each other at the same upright 61 of the elevator car 60 in order to engage with the same car guide member 14.

[0049] Figure 3 shows a schematic sectional view of an elevator safety gear 20 according to an exemplary embodiment of the invention, and Figure 4 shows a schematic sectional view of an elevator safety gear according to another exemplary embodiment of the invention.

[0050] The elevator safety gear 20 comprises an engagement member 26 with an engagement face 23 extending in the longitudinal direction basically parallel to the car guide member 14. The engagement face 23 faces the car guide member 14 and is configured for engaging with the car guide member 14.

[0051] Opposite to the engagement face 23, the engagement member 26 has an actuated face 25 facing away from the car guide member 14. The actuated face 25 is inclined with respect to the longitudinal direction. The actuated face 25 in particular is inclined at an angle 0° < α < 10° (see Figure 3), more particularly at an angle 2,5° < α < 7,5°, e.g. at an angle α of 5,4° with respect to the longitudinal direction.

[0052] The elevator safety gear 20 further comprises an actuator member 30 with an actuation face 31 oriented towards the actuated face 25 of the engagement member 26. The actuation face 31 is inclined with respect to the longitudinal direction at an angle β (see Figure 3) . The angle β of the actuation face 31 differs from the angle α of the actuated face 25 (α ≠ β). The angle β in particular is larger than the angle α (β > α). The actuation face 31 in particular may be inclined at an angle 10° < β < 40°, more particularly at an 15° < β < 30°, e.g. at an angle β of 20° with respect to the longitudinal direction.

[0053] A force transfer member 28 is sandwiched between the engagement member 26 and the actuator member 30. The force transfer member 28 comprises a first face 27 (shown on the left side in Figures 3 and 4) facing and extending parallel to the actuated face 25 of the engagement member 26 and an opposing second face 29 (shown on the right side in Figures 3 and 4) facing and extending parallel to the actuation face 31 of the actuator member 30.

[0054] The extension (height) a₁ (see Figure 3) of the engagement member 26 and the force transfer member 28 in the longitudinal direction may be in the range of 20 mm to 80 mm, in particular in the range of 30 mm to 70 mm, more particularly in the range of 50 mm to 60 mm.

[0055] The extensions (widths) b₁, c₁ (see Figure 3) of the engagement member 26 in the horizontal direction, i.e. orthogonally to the longitudinal direction, may be in the range of 10 mm to 30 mm,in particular in the range of 15 mm to 25 mm, and the extensions (widths) b₂, c₂ (see Figure 3) of the force transfer member 28 in the horizontal direction may be in the range of 10 mm to 50 mm, respectively.

[0056] The extension (height) a₃ (see Figure 3) of the actuator member 30 in the longitudinal direction may be in the range of 10 mm to 60 mm, in particular 20 mm to 40 mm, more particularly 30 mm, and the extensions (widths) b₃, c₃ (see Figure 3) of the actuator member 30 in the horizontal direction may be in the range of 10 mm to 50 mm, respectively.

[0057] These dimensions, however, are given only as examples and the skilled person will understand that they may be varied according to the respective needs.

[0058] The elevator safety gear 20 comprises a support 32 supporting the actuator member 30, so that it is not movable in the horizontal direction.

[0059] The actuation face 31 of the actuator member 30 may be supported elastically with respect to the support 32 by means of at least one elastic element 36, e.g. by a spring, arranged between said support 32 and the actuation face 31 of the actuator member 30, as schematically illustrated in Figure 3.

[0060] The actuator member 30, for example, may be split into two parts as depicted in Figure 4, a first part 30a being fixed to the support 32, and a second part 30b comprising the actuation face 31, the second part 30b being elastically coupled with the first part 30a by the at least one elastic element 36.

[0061] In the embodiment depicted in Figures 3 and 4, the second face 29 of the force transfer member 28 abuts against the actuation face 31 of the actuator member 30, and the actuated face 25 of the engagement member 26 abuts against the first face 27 of the force transfer member 28.

[0062] Movement of the force transfer member 28 with respect to the actuator member 30 in the longitudinal direction is prevented by fixing elements 34 arranged above and below the force transfer member 28.

[0063] The engagement member 26, the force transfer member 28 and the actuator member 30, however, are movable in a plane extending transversely, in particular orthogonally, to the longitudinal direction, respectively. I.e. the engagement member 26, the force transfer member 28 and the force transfer member 28 are movable transversely to the extension of the guide member 14.

[0064] The elevator safety gear 20 further comprises an actuator 38 configured for selectively exerting an actuating force F_a onto the actuator member 30. The actuating force F_a in particular may be oriented in the longitudinal direction, i.e. parallel to the guide member 14.

[0065] When such a longitudinally oriented actuating force F_a is exerted onto the actuator member 30, the actuation face 31 of the actuator member 30 is pressed against the second face 29 of the force transfer member 28. Due to the inclined orientation of the second face 29 and the actuation face 31, the force transfer member 28 is pushed towards the engagement member 26, i.e. towards the left side in the orientation depicted in Figures 3 and 4, respectively.

[0066] This presses the first face 27 of the force transfer member 28 against the actuated face 25 of the engagement member 26 pushing the engagement member 26 towards the car guide member 14.

[0067] In consequence, the engagement member 26 contacts the car guide member 14 and friction between the engagement member 26 and the car guide member 14 pulls the engagement member 26 in the longitudinal direction (upwards in Figures 3 and 4).

[0068] As a result, the engagement member 26 is wedged and clamped between the car guide member 14 and the force transfer member 28 braking the movement of the elevator safety gear 20, and thus also the movement of the elevator car 60 to which the elevator safety gear 20 is mounted, along the car guide member 14.

[0069] Due to the difference between the angles α, β of the first and second faces 27, 29 of the force transfer member 28, the combination of the engagement member 26, the force transfer member 28 and the actuator member 30 acts as a lever mechanism amplifying the actuating force F_a applied by the actuator 38.

[0070] For example, with α = 5,4° and β = 20°, the engagement member 26 is pressed against the car guide member 14 with an engagement force F_b which is approximately ten times larger than the actuating force F_a supplied by the actuator 38.

[0071] In consequence, a small and cheap actuator 38 providing only a small actuating force F_a may be employed. Using a small actuator 38 further allows reducing the weight and the dimensions of the elevator safety gear 20.

[0072] The skilled person understands that the angles α, β may be varied in order to modify the lever ratio, i.e. the amplification of the actuating force F_a, according to the respective needs.

[0073] At least one of the actuation face 31, the actuated face 25, the first face 27 and the second face 29 may be provided with a low friction coefficient in order to reduce the friction between the engagement member 26, the force transfer member 28 and the actuator member 30, respectively.

[0074] Said at least one face 25, 27, 29, 31 having a low friction coefficient in particular may be provided by applying a coating 40 with a low friction coefficient to at least one face of at least one of the members.

[0075] Low friction between the faces 25, 27, 29, 31 of the members 26, 28, 30 enhances the reliability and shortens the activation time of the elevator safety gear 20. It further reduces the actuating force F_a needed for actuating the elevator safety gear 20.

[0076] Additionally or alternatively, a lubricant 42 such as oil or grease may applied to the first face 27 of the force transfer member 28 and the actuated face 25 of the engagement member 26 and/or to the second face 29 of the force transfer member 28 and the actuation face 31 of the actuator member 30, respectively.

[0077] Although an elevator safety gear 20 attached to the elevator car 60 has been described with reference to Figures 2 to 4, the skilled person will understand that an elevator safety gear 20 according to an exemplary embodiment of the invention may also be arranged at a counterweight 19. In this case, the engagement member 26 is configured for engaging with the counterweight guide member 15 instead of the car guide member 14.

[0078] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adopt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention shall not be limited to the particular embodiment disclosed, but that the invention includes all embodiments falling within the scope of the dependent claims.

References

[0079] 

2

elevator system

3

tension member

4

hoistway

5

drive unit

7a

landing control panel

7b

elevator car control panel

8

landing

11

landing door

12

elevator car door

14

car guide member

15

counterweight guide member

19

counterweight

20

elevator safety gear

23

engagement face

25

actuated face

26

engagement member

27

first face

28

force transfer member

29

second face

30

actuator member

31

actuation face

32

support

34

fixing element

36

elastic element

38

actuator

40

coating

42

lubricant

60

elevator car

61

upright

62

car roof

63

crossbar

64

car floor

66

car side wall

68

interior space of the elevator car

70

passenger

Claims

1. An elevator safety gear (20) comprising:

an engagement member (26) with an engagement face (23) extending in a longitudinal direction and configured for engaging with a guide member (14, 15) of an elevator system (2), and an opposing actuated face (25), which is inclined with respect to the longitudinal direction;

an actuator member (30) comprising an actuation face (31) facing the actuated face (25) of the engagement member (26) and being inclined with respect to the longitudinal direction; and

a force transfer member (28) sandwiched between the engagement member (26) and the actuator member (30), the force transfer member (28) comprising a first face (27) extending parallel to the actuated face (25) of the engagement member (26) and a second face (29) extending parallel to the actuation face (31) of the actuator member (30).

2. The elevator safety gear (20) according to claim 1, wherein the first face (27) of the force transfer member (28) abuts against the actuated face (25) of the engagement member (26) and/or wherein the second face (29) of the force transfer member (28) abuts against the actuation face (31) of the actuator member (30).

3. The elevator safety gear (20) according to claim 1 or 2, wherein the actuation face (31) of the actuator member (30) is elastically movable in a direction transverse to the longitudinal direction.

4. The elevator safety gear (20) according to claim 3, wherein the actuation face (31) of the actuator member (30) is elastically supported by an elastic element (36), in particular by a spring.

5. The elevator safety gear (20) according to any of the preceding claims, wherein the force transfer member (28) is supported so that it cannot move in the longitudinal direction.

6. The elevator safety gear (20) according to any of the preceding claims, wherein the actuated face (25) of the engagement member (26) is oriented at an angle α of 0° < α < 10°, particularly at an angle 2,5° < α < 7,5°, more particularly at an angle α of 5,4° with respect to the longitudinal direction.

7. The elevator safety gear (20) according to any of the preceding claims, wherein the actuation face (31) of the actuator member (30) is oriented at an angle β of 0° < β < 40°, particularly at an 15° < β < 30°, more particularly at an angle β of 20° with respect to the longitudinal direction.

8. The elevator safety gear (20) according to any of the preceding claims, further comprising an actuator (38) which is configured for actuating the actuator member (30), in particular for exerting an actuating force (F_a) in a longitudinal direction onto the actuator member (30).

9. The elevator safety gear (20) according to claim 8, wherein the actuator (38) is configured for moving the actuator member (30) over a distance of 1 mm to 5 mm, in particular over a distance of 2 mm to 3 mm.

10. The elevator safety gear (20) according to any of the preceding claims, wherein at least one of the actuation face (31), the actuated face (25), the first face (27) and the second face (29) has a low friction coefficient, wherein said at least one face (25, 27, 29, 31) in particular is covered by a coating (40) having a low friction coefficient.

11. The elevator safety gear (20) according to any of the preceding claims, wherein a lubricant (42) is applied to the first face (27) of the force transfer member (28) and the actuated face (25) of the engagement member (26) and/or to the second face (29) of the force transfer member (28) and the actuation face (31) of the actuator member (30).

12. An elevator car (60) comprising at least one elevator safety gear (20) according to any of claims 1 to 11.

13. A counterweight for an elevator system (2), the counterweight (19) comprising at least one elevator safety gear (20) according to any of claims 1 to 11.

14. An elevator system (2) comprising at least one car guide member (14) and at least one elevator car (60) according to claim 12 traveling along said at least one car guide member, and/or at least one counterweight guide member (15) and a counterweight (19) according to claim 13 traveling along said at least one counterweight guide member.

15. Method of actuating an elevator safety gear (20) according to any of claims 1 to 11, wherein the method includes exerting a force in the longitudinal direction onto the actuator member (30).

Drawing