WO2011146073A1

WO2011146073A1 - Elevator holding and safety brake engagement mechanism

Info

Publication number: WO2011146073A1
Application number: PCT/US2010/035755
Authority: WO
Inventors: Zbigniew Piech
Original assignee: Otis Elevator Company
Priority date: 2010-05-21
Filing date: 2010-05-21
Publication date: 2011-11-24

Abstract

A braking mechanism (38) for an elevator car (16) includes a brake member (40, 66) operably connected to the elevator car (16). The brake member (40, 66) is at least partially insertable into a plurality of recesses (28) located at a guide rail (14) for the elevator car (16), to prevent movement of the elevator car (16) along the guide rail (14). An actuator (46) is operably connected to the brake member (40, 66), and is configured to move the brake member (40, 66) toward the guide rail (14) and at least partially into the plurality of recesses (28) for engagement therewith.

Description

ELEVATOR HOLDING AND SAFETY BRAKE ENGAGEMENT MECHANISM

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to elevator systems. More specifically, the subject disclosure relates to holding and braking mechanisms for elevator systems.

[0002] Elevator systems typically include an elevator car suspended in a hoistway by a number of suspension ropes. To guide the elevator car in the hoistway, a number of guide rails are arranged in the hoistway, for example, from the top to bottom of the hoistway. The elevator car is connected to the guide rails via one or more guide shoes such that the elevator car follows a path defined by the guide rails as it moves through the hoistway. Further, in some elevator systems, a braking mechanism connected to the elevator car acts on the guide rails to slow and/or stop the elevator car in the hoistway.

[0003] The typical brake mechanism includes a braking shoe positioned at each guide rail. When slowing and/or holding of the elevator car is desired, the braking show is moved toward the guide rail and applies a frictional force to the guide rail to slow and/or hold the elevator car. The reliance on friction forces in braking of the elevator car can be unpredictable. The art would well receive a braking mechanism which does not rely on friction forces to slow and/or hold the elevator car.

BRIEF DESCRIPTION OF THE INVENTION

[0004] According to one aspect of the invention, a braking mechanism for an elevator car includes a brake member connected to the elevator car. The brake member is at least partially insertable into a plurality of recesses located in a guide rail for the elevator car, to prevent movement of the elevator car along the guide rail. An actuator is operably connected to the braking cam, and is configured to move the brake member toward the guide rail and into the plurality of recesses for engagement therewith.

[0005] According to another aspect of the invention, an elevator system includes an elevator car located in a hoistway. One or more guide rails are fixed in the hoistway in operable communication with the elevator car. At least one of the guide rails includes a plurality of recesses arrayed along the guide rail. A brake member is operably connected to the elevator car and is at least partially insertable into the plurality of recesses to prevent movement of the elevator car along the guide rail. [0006] According to yet another aspect of the invention, a method for stopping and/or holding an elevator car at a desired location in a hoistway includes providing one or more guide rails in the hoistway, each guide rail including a plurality of recesses arrayed along the guide rail. A brake member is located at the elevator car and moved toward the guide rail. The brake member is at least partially inserted into a recess of the plurality of recesses to prevent further movement of the elevator car along the guide rail.

[0007] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

[0009] FIG. 1 is a schematic view of an embodiment of a elevator system;

[0010] FIG. 2 is a perspective view of an embodiment of a guide rail for an elevator system;

[0011] FIG. 3 is a cross-sectional view of an embodiment of a guide rail;

[0012] FIG. 4 is a cross-sectional view of a braking mechanism for an elevator system;

[0013] FIG. 5 is a cross-sectional view of another embodiment of a braking mechanism for an elevator system;

[0014] FIG. 6 is a cross-sectional view of yet another embodiment of a braking system for an elevator system;

[0015] FIG. 7 is a cross-sectional view of still another embodiment of a braking mechanism for an elevator system; and

[0016] FIG. 8 is a perspective view of another embodiment of a guide rail for an elevator system.

[0017] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Shown in FIG. 1 is an embodiment of an elevator system 10. The elevator system 10 is located in a hoistway 12 and includes one or more guide rails 14 affixed to the hoistway 12. The guide rails 14 are connected to an elevator car 16 to guide the movement of the elevator car 16 through the hoistway 12. In some embodiments, the elevator car 16 includes a guide shoe 18 which interfaces with the guide rail 14.

[0019] An embodiment of a guide rail 14 is shown in FIG. 2. The embodiment of FIG. 2 is formed from a sheet metal, which may be bent, roll-formed, welded, and/or otherwise manipulated into the final cross-sectional shape. The guide rail 14 includes a base 20 configured to rest against the wall of the hoistway 12. A web 22 extends from the base 20, in a direction toward the elevator car 16 to a tip section 24. The web 22 of the guide rail 14 in embodiments formed from sheet metal includes two or more material thicknesses 26, in particular the embodiment shown in FIG. 2 includes four material thicknesses 26. It is to be appreciated that while the embodiments illustrated herein reflect guide rails 14 formed from a sheet metal, other embodiments may utilize guide rails 14 formed from a solid piece of material such as steel.

[0020] Referring to FIG. 3, the web 22 of the guide rail 14 includes a plurality of recesses 28 extending into the web 22. The recesses 28 may be formed by punching, milling, or other suitable means. To maintain greater structural integrity of the web 22, the recesses 28 in some embodiments extend only partially through the web 22, for example, through one material thickness 26. The plurality of recesses 28 are arranged on an exterior surface 32 of the web 22 along a length 30 of the guide rail 14. In some embodiments, recesses 28 are located at both exterior surfaces 32 of the web 22. In such embodiments, the positions of recesses 28 at a first exterior surface 32 are staggered along the length 30 of the guide rail 14 relative to recesses 28 located along a second exterior surface 32. In other words, recesses 28 located at the first exterior surface 32 are not at the same position along the length 30 of the guide rail 14 as recesses 28 located at the second exterior surface 32. Further, as shown in FIG. 3, the recesses 28 are not perpendicular to the guide rail 14, but rather are canted at an angle 36 relative to the direction in which the web 22 extends.

[0021] Referring now to FIG. 4, the recesses 28 are configured to interact with a braking mechanism 38 to stop and/or hold the elevator car 16. With the guide rail 14 secured in the hoistway 12, the braking mechanism 38 is located at the elevator car 16. In some embodiments, the braking mechanism 38 includes a brake member, which in this embodiment is a braking cam 40 mounted to the elevator car 16. In the embodiment shown in FIG. 4, the braking cam 40 is rotably mounted to the elevator car 16 at a cam pivot 42. A brake arm 44 extends from the braking cam 40 to a braking actuator, for example a solenoid 46. Although the braking actuator in the embodiment of FIG. 4 is a solenoid 46, it is to be appreciated that other types of actuators including electrical, electromagnetic, and hydraulic actuators are contemplated to be within the scope of the present disclosure.

[0022] The braking cam 40 also includes a cam tab 48 insertable into the recesses 28 when the braking cam 40 is rotated toward the guide rail 14. The cam tab 48 in configured to hold the position of the elevator car 16 when the cam tab 48 is inserted into the recess 28, but can be easily removed from the recess 28 when the braking cam 40 is rotated away from the guide rail 14. For example, as shown in FIG. 4, the cam tab 48 may include a tab radius 50 which allows for ease of removal of the cam tab 48 from the recess 28 when desired.

[0023] In the illustrative embodiment of FIG. 4, in which the actuator 46 is a solenoid, the brake arm 44 is connected to a solenoid plunger 52 of the solenoid 46 which are both biased away from the solenoid 46 by a spring 54. When the solenoid 46 is energized by a flow of current running to the solenoid 46, the force of spring 54 is overcome and solenoid plunger 52 advances into the solenoid 46. The advancement of the plunger causes the brake arm 44 to move the braking cam 40 such that it rotates around the cam pivot 42 away from guide rail 14. On the other hand, when the flow of current to the solenoid 46 is interrupted, the spring 54 bias forces the brake arm 44 to rotate the braking cam 40 toward the guide rail 14 so the cam tab 48 may be inserted into the recess 28.

[0024] During normal movement of the elevator system 10, the solenoid 46 is activated. When the elevator car 16 stops at a desired location, such as a floor level, current to the solenoid 46 is turned off, causing the spring 54 to push the brake arm 44 toward the guide rail 14, in turn urging the cam tab 48 into the recess 28 of the guide rail 14. When the elevator car 16 is readying for departure from the floor level, current is again supplied to the solenoid 46, retracting the cam tab 48 from the recess 28.

[0025] The safety brake function of the braking mechanism 38 shown in FIG. 4 is executed by interrupting the current supply to the solenoid 46 when the elevator car 16 is in motion. The spring 54 pushes the braking cam 40 toward the guide rail 14. As the braking cam 40 approaches a recess 28, cam tab 48 will be urged by the force of spring 54 to enter the recess 28 and slow the motion of the elevator car 16. In some cases, the speed of the elevator car 16 will be great enough that the cam tab 48 of the braking cam 40 will not remain in the recess 28 and stop the elevator car 16, but instead braking cam 40 will be pushed away from the guide rail 14 as the force of the cam tab 48 against guide rail 14 at the end of recess 28 overcomes the force of the spring 54 and pushes the cam tab 48 out of the recess 28. As the braking cam 40 approaches the next recess 28 along the guide rail 14, as the elevator car 16 continues in motion, cam tab 48 will again be urged by the force of spring 54 to enter the next recess 28. If the speed of the elevator car 16 is still too great, the braking cam 40 will reduce the speed of, but not stop the elevator car 16. This process is repeated until the speed of elevator car 16 is not too great for braking cam 40 to successfully engage a recess 28 to stop the elevator car 16.

[0026] As stated above with respect to FIG. 3, in some embodiments, recesses 28 are located at both exterior surfaces 32 of the web 22 of the guide rail 14. In such embodiments, solenoids 46 may be disposed at each lateral side 58 of the guide rail 14 to control the braking cams 40 individually. As illustrated in FIG. 4, during safety brake operation, a braking cam 40a on one lateral side 58 of the guide rail 14 is extended to a recess 28, while a braking cam 40b on the opposing lateral side 58 is disposed at the guide rail 14 at a raised portion 56 between adjacent recesses 28. If the elevator car 16 is traveling at a velocity to great for the extended braking cam 40a to stop the elevator car 16, the elevator car 16 advances until the braking cam 40b extends into a recess 28 on the opposing lateral side 58, further slowing the elevator car 16. With braking cams 40 disposed at both lateral sides 58 of the guide rail 14, and with the recesses 28 staggered in their respective positions along both exterior surface 32 of the guide rail 14, the distance the elevator car 16 must travel before being brought to a stop under safety brake operation is reduced.

[0027] Another embodiment of a braking mechanism 38 is shown in FIG. 5. In this embodiment, braking cams 40 are located at both lateral sides 58 of the guide rail 14. Movement of both braking cams 40 are controlled via a single solenoid 46 with links 60 that connect the braking cams 40 to the solenoid plunger 52 of the solenoid 46 via brake arms 44. Movement of braking cams 40a, 40b relative to the guide rail 14 is controlled by the supply of current to the single solenoid 46 in the same way as described above with respect to FIG. 4.

[0028] Yet another embodiment is shown in FIG. 6. This embodiment includes multiple braking cams 40 at each lateral side 58 of the guide rail 14. The braking cams 40 may be operated by individual solenoids 46 as in the embodiment of FIG. 4, or as shown in FIG. 6, the braking cams 40 at each lateral side 58 may be controlled by a single solenoid 46. The braking cams 40 are disposed in a cam housing 62 which is operably connected to the solenoid 46. When the solenoid 46 is deenergized, the spring 54 pushes the cam housing 62, with the braking cams 40 disposed therein, toward the guide rail 14. The braking cams 40 are coupled to cam springs 64 which bias the rotational position of the braking cams 40 to a desired position, for example perpendicular to the lateral side 58. In some embodiments, the position of the braking cams 40 at a first lateral side 58 are staggered along the length 30 of the guide rail 14 relative to the braking cams 40 located at the opposing lateral side 58. This staggered configuration further decreases the distance that must be traveled by the elevator car 16 during safety brake operation before the car is brought to a stop by the braking cams 40. Further, multiple braking cams 40 staggered at each lateral side 58 of the guide rail 14 reduce misalignment between the elevator car 16 and a hall floor (not shown) when the elevator car 16 stops at the hall floor.

[0029] Another embodiment is shown in FIG. 7. In this embodiment, the brake member is a brake roller 66 mounted to a roller support 68. The roller support 68 is connected to the brake arm 44 and solenoid plunger 52. Further, the roller support 68 is biased toward the guide rail 14 by the spring 54. When the solenoid 46 is deenergized, the roller support 68 and brake roller 66 extend angularly toward the guide rail 14. In the embodiment shown in FIG. 7, the guide rail 14 includes a plurality of protrusions 70 to interact with the advancing brake roller 66. FIG. 8 is a more detailed view of the guide rail 14 used in the elevator system of FIG. 7. As shown in FIG. 8, the protrusions 70 are arrayed in a pattern of pairs of protrusions 70 with recesses 28 disposed therebetween, into which the brake roller 66 can be received. Movement of the rollers into recesses 28 in this embodiment has the same function and effect on car movement as movement of cam tabs 48 into recesses 28 in the above- described embodiment.

[0030] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

CLAIMS:

1. A braking mechanism (38) for an elevator car (16) comprising:

a brake member (40, 66) operably connected to the elevator car (16), the brake member (40, 66) at least partially insertable into a plurality of recesses (28) disposed along a guide rail (14) for the elevator car (16), to stop and/or hold the elevator car (16) at a desired location on the guide rail (14); and

an actuator (46) operably connected to the brake member (40, 66), the actuator (46) configured to move the brake member (40, 66) toward the guide rail (14) and into the plurality of recesses (28) for engagement therewith.

2. The braking mechanism (38) of Claim 1, wherein the actuator (46) is a solenoid

(46).

3. The braking mechanism (38) of Claim 2, wherein solenoid (46) is configured to move the brake member (40, 66) toward the guide rail (14) when the solenoid (46) is de- energized.

4. The braking mechanism (38) of Claim 1, further comprising a biasing member (54) in operable communication with the brake member (40, 66) to bias the brake member (40, 66) toward the guide rail (14).

5. The braking mechanism (38) of Claim 4, wherein the biasing member (54) is a spring (54).

6. The braking mechanism (38) of Claim 1, wherein the brake member (40) is rotatably secured to the elevator car (16).

7. The braking mechanism (38) of Claim 1, further comprising two or more brake members (40, 66).

8. The braking mechanism (38) of Claim 7, wherein two brake members (40, 66) of the two or more brake members (40, 66) are disposed at opposing lateral sides (58) of the guide rail (14).

9. The braking mechanism (38) of Claim 8, wherein the two brake members (40, 66) are staggered relative to each other along a length (30) of the guide rail (14).

10. The braking mechanism (38) of Claim 7, wherein two or more of the brake members (40, 66) are operably connected to a single actuator (46).

11. The braking mechanism (38) of Claim 7, comprising four brake members (40,

66).

12. An elevator system (10) comprising:

an elevator car (16) disposed in a hoistway (12);

one or more guide rails (14) fixed in the hoistway (12) in operable communication with the elevator car (16), at least one guide rail (14) of the one or more guide rails (14) including a plurality of recesses (28) arrayed along the guide rail (14); and

a brake member (40, 66) operably connected to the elevator car (16), the brake member (40, 66) at least partially insertable into one of the plurality of recesses (28) to prevent further movement of the elevator car (16) along the guide rail (14).

13. The elevator system (10) of Claim 12, wherein the plurality of recesses (28) is arrayed along opposing lateral sides (58) of the one or more guide rails (14).

14. The elevator system (10) of Claim 13, wherein the recesses (28) disposed at a first lateral side (58) of the guide rail (14) are staggered relative to the recesses (28) disposed at the opposite lateral side (58) of the guide rail (14).

15. The elevator system (10) of Claim 13, comprising two or more brake members (40, 66), wherein two brake members (40, 66) of the two or more brake members (40, 66) are disposed at opposing lateral sides (58) of the guide rail (14).

16. The elevator system (10) of Claim 14, wherein the two brake members (40, 66) disposed at opposing lateral sides (58) of the guide rail (14) are staggered relative to each other along a length (30) of the guide rail (14).

17. The elevator system (10) of Claim 13, comprising four brake members (40, 66).

18. The elevator system (10) of Claim 12, further comprising an actuator (46) operably connected to the brake member (40, 66), the actuator (46) configured to actuate the brake member (40, 66) into engagement with the recesses (28) in the guide rail (14).

19. The elevator system (10) of Claim 18, wherein the actuator (46) is a solenoid

(46).

20. The elevator system (10) of Claim 19, wherein solenoid (46) is configured to move the brake members (40, 66) toward the guide rail (14) when the solenoid (46) is de- energized.

21. The elevator system (10) of Claim 18, wherein actuator (46) is operably connected to two or more brake members (40, 66).

22. The elevator system (10) of Claim 12, further comprising a biasing member (54) in operable communication with the brake member (40, 66) to bias the brake member (40, 66) toward the guide rail (14).

23. A method for stopping and/or holding an elevator car (16) at a desired location in a hoistway (12) comprising:

providing one or more guide rails (14) in the hoistway (12), each guide rail (14) including a plurality of recesses (28) arrayed along the guide rail (14);

locating a brake member (40, 66) at the elevator car (16);

moving the brake member (40, 66) toward the guide rail (14); and

at least partially inserting the brake member (40, 66) into a recess (28) of the to prevent further movement of the elevator car (16) along the guide rail (14).

24. The method of Claim 23, wherein moving the brake member (40, 66) toward the guide rail (14) comprises activating an actuator (46) operably connected to the braking cam (40) to urge the brake member (40, 66) toward the guide rail (14).

25. The method of Claim 24, wherein the actuator (46) is a solenoid (46), and activating the actuator (46) comprises de-energizing the solenoid (46).

26. The method of Claim 23, further comprising providing a biasing member (54) to bias the brake member (40, 66) toward the guide rail (14).

27. The method of Claim 23, wherein locating a brake member (40, 66) at the elevator car (16) comprises locating two or more brake members (40, 66) at the elevator car (16).

28. The method of Claim 27, further comprising moving two brake members (40, 66) of the two or more brake members (40, 66) toward opposing lateral sides (58) of the guide rail (14).

29. The method of Claim 27, further comprising moving the two or more brake members (40, 66) toward the guide rail (14) via activation of a single actuator (46).