Braking device for an elevator

Information

  • Patent Grant
  • 6823969
  • Patent Number
    6,823,969
  • Date Filed
    Monday, November 25, 2002
    21 years ago
  • Date Issued
    Tuesday, November 30, 2004
    19 years ago
Abstract
A braking device acts on a guide rail and consists of a housing that is arranged at an elevator car yoke and serves as a support for spring packets and/or for adjusting packets. The housing also serves as a support and guide for chock guide elements that in turn retain and guide brake chocks with brake linings. Pushrods engage at one end at the brake chocks, and at the other end are pivotably connected to an actuating fork. Upon braking of the elevator car, the actuating fork is moved at the pushrod end in the direction of the braking device. The guided brake chocks with the brake linings slide in the braking device. At the same time the brake linings are moved at the guide leg of the guide rail. The brake chocks are moved in the braking device and the spring and adjusting packets are stressed, whereby a braking force for stopping an elevator car or a counterweight is generated.
Description




BACKGROUND OF THE INVENTION




The present invention relates to a braking device for an elevator with an elevator car and a counterweight, which are movable along guide rails in an elevator shaft, wherein the braking device is arranged at the elevator car or at the counterweight and in the case of excess speed stops the elevator car or the counterweight at the guide rails by means of spring elements and brake chocks.




There is shown in the U.S. Pat. No. 5,782,319 a braking device for an elevator, which stops the elevator car in the case of emergency. The elevator car drives, by means of an endless cable, a rotating speed limiter, which blocks in the case of a specific excess speed of the elevator car. The blocked speed limiter also blocks the endless cable, but the elevator car moves further downwardly, wherein the blocked endless cable, which is connected with a release lever mechanism of the braking device, trips the braking device. In that case two guided chocks of the braking device are pushed upwardly. The braking force is generated by friction between the chocks and the guide rail of the elevator car. The braking force is on the one hand dependent on the friction of the chocks on the guide rail and on the other hand dependent on a C-shaped compact spring packet at the ends of which are provided guides for the chocks.




A disadvantage of this known device is that the spring packet and the guides are cast from one piece. The spring packet unit has to be manufactured in accordance with the respective braking force to be exerted, which increases the cost of the braking device.




SUMMARY OF THE INVENTION




The present invention concerns a braking device for attachment to one of an elevator car and a counterweight that are movable along guide rails in an elevator shaft, wherein the braking device is actuated to engage a guide rail in the case of excess speed. The braking device includes: a housing; a pair of brake chocks mounted on the housing and movable from a disengaged position to a guide rail engaging position; and at least one spring packet mounted on the housing and having opposed ends connected to associated ones of the brake chocks, the at least one spring packet being of modular construction having lamellae selected to produce a predetermined braking force. The braking device has each end of the spring packet detachably connected to the associated brake chock by a spring bracket. The braking device also can include at least one adjusting packet mounted on the housing and having opposed ends connected to an associated one of the brake chocks.




The advantages achieved by the braking device according to the present invention are essentially that a simple construction of the braking device is possible. The braking device consists of only a few different components. Further, it is advantageous that the braking device is adaptable, with the same components, to different braking forces. The braking device is thus usable, without great expense, for elevator cars or counterweights with different masses to be braked. Moreover, the braking device according to the present invention offers the possibility of fine adjustment with respect to the braking force. The spring elements consist of lamellae producible in a simple manner. A greater or lesser number of lamellae can be used in accordance with the respective braking force required.











DESCRIPTION OF THE DRAWINGS




The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:





FIG. 1

is a perspective view of an elevator car with the braking device according to the present invention;





FIG. 2

is an enlarged perspective view of the braking device shown in

FIG. 1

acting on a guide rail;





FIG. 3

is a plan view of a support body with spring elements according to the present invention;





FIG. 4

is a cross-sectional view of the support body taken along the line A—A in

FIG. 3

; and





FIG. 5

is a perspective view of the support body shown in FIG.


3


.











DESCRIPTION OF THE PREFERRED EMBODIMENT





FIG. 1

shows an elevator car


1


movable in an elevator shaft (not shown) wherein the elevator car


1


is guided by means of guide rails


2


extending over the shaft height. The elevator car


1


is provided with a door


1


.


1


and is carried by a support frame


3


with a lower yoke


4


and an upper yoke


5


. A support cable (not shown), one end of which is connected with, for example, the upper yoke


5


and the other end of which is connected with a counterweight (not shown), is guided over a drive pulley (not shown). A respective braking device


6


, which stops the elevator car


1


in the case of emergency, is arranged at the lower yoke


4


on an associated guide rail


2


. The elevator car


1


drives, by means of an endless cable


7


, a rotating speed limiter (not shown) that blocks in a downward direction in the event of a specific excess speed of the elevator car


1


. The blocked speed limiter also blocks the endless cable


7


guided over a tensioning roller (not shown) arranged in the shaft pit, but the elevator car


1


moves further downwardly, whereby the blocked endless cable


7


connected with a trigger lever mechanism


8


trips the braking device


6


. The trigger lever mechanism


8


connected with the endless cable


7


consists of a rotational axle


8


.


1


at which an actuating fork


8


.


2


, which trips the braking device


6


, is arranged. The actuating fork


8


.


2


of the opposite braking device


6


is actuated by means of a connecting rod


8


.


3


arranged at the rotational axle


8


.


1


. When the endless cable


7


, also known as a limiter cable, is blocked, the rotational axle


8


.


1


is rotated in clockwise sense as seen from the car door


1


.


1


. In that case the actuating fork


8


.


2


is raised at the free end.




If the braking device


6


is analogously arranged at the upper yoke


5


, the elevator car


1


can be stopped in upward direction for cases of emergency. The braking device


6


can also be arranged at the counterweight.





FIG. 2

shows details of the braking device


6


acting on a guide leg


2


.


1


of the guide rail


2


. In order to make the details of the braking device


6


visible, the guide rail


2


is illustrated as broken away in the region of the braking device


6


. The braking device


6


consists of a housing


9


which is arranged at the yoke


4


,


5


and which serves as a support for spring packets


10


and/or for adjusting packets


11


. The housing


9


also serves as a support and guide for chock guide elements


12


, which in turn retain and guide brake chocks


13


with brake linings


14


. A pushrod


15


engages at one end at the brake chock


13


, and at the other end the pushrod


15


is pivotably connected with the actuating fork


8


.


2


.




The spring packets


10


are of modular construction, as are the adjusting packets


11


, and both are detachably connected at each end with a respective one of the wedge guide elements


12


by means of a respective spring bracket


16


, wherein lugs


10


.


1


or


11


.


1


of the spring packets


10


or adjusting packets


11


prevent the packets from slipping off the chock guide elements


12


. The packets


10


,


11


are interconnected at each end by means of, for example, a threaded pin


17


and nuts


17


.


1


, wherein first seats


12


.


2


of the chock guide elements


12


and at least one second seat


9


.


2


of the housing


9


hold the overall packet consisting of the spring packets


10


and the adjusting packets


11


.




In the illustrated example, a spring packet


10


consists of ten lamellae


10


.


2


of the same thickness and the same material. The geometrically somewhat smaller adjusting packets


11


consist, in the illustrated example, of three lamellae


11


.


2


. The lamellae


10


.


2


,


11


.


2


are, for example, punched out of sheet metal. Other lamella materials or different lamella thicknesses are also possible. The lamellae


10


.


2


,


11


.


2


can also have a shape departing from the illustrated “C” shape. The individual spring packets


10


or adjusting packets


11


of the braking device


6


can also have a different number of lamellae. Different spring constants, which have a direct effect on the braking force, can be produced in accordance with the respective number of lamellae, material, lamella thickness or lamella shape.




The chock guide element


12


is guided in first grooves


9


.


1


of the housing


9


and has an extension


12


.


1


. In the case of normal operation, the brake chock


13


is held in a rest position by means of the extension


12


.


1


and the pushrod


15


.




In the case of an emergency, the limiter cable


7


is blocked by the speed limiter detecting excess speed. The actuating fork


8


.


2


is thereby, as illustrated further above, moved at the pushrod end in the direction of the braking device


6


. The brake chocks


13


, which are guided in second grooves


12


.


3


of the chock guide elements


12


, with the brake linings


14


slide in the braking device


6


. At the same time the brake linings


14


are moved against the guide leg


2


.


1


of the guide rail


2


. Due to the wedge-shaped arrangement of the chock guide elements


12


and the friction between the brake linings


14


on the guide leg


2


.


1


, the brake chocks


13


are moved in the braking device


6


and the spring and adjusting packets


10


,


11


stressed, wherein the braking force, which is dependent on the friction constant between the brake linings


14


and the guide leg


2


.


1


as well as on the spring constant, for stopping the elevator car or the counterweight is generated.




As illustrated in

FIGS. 3

to


5


, the spring packets can be arranged at a support body


20


, wherein the support body, which is, for example, C-shaped, acts on the chock guide elements


12


. The spring packets


21


consist of at least one lamella


21


.


1


and are laid in grooves


22


of the support body


20


. In the illustrated example, three grooves and three spring packets


21


are provided. A greater or lesser number than three grooves


22


can also be provided, wherein the grooves


22


can also be of different widths. The spring packets


21


laid in the narrow grooves


22


can serve as adjusting packets. During the braking process the support body


20


and the spring packets


21


are stressed and the braking force for stopping the elevator car or the counterweight is produced. The braking device


6


can be provided with one or more of the support bodies


20


.




In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.



Claims
  • 1. A braking device for an elevator with an elevator car and an counterweight movable along guide rails in an elevator shaft, wherein the braking device is arranged at the elevator car or at the counterweight and in the case of excess speed stops the elevator car or the counterweight at the guide rails by means of spring elements and brake chocks, comprising: a plurality of spring elements of modular construction, said spring elements being selectively assembled for generating different braking forces, wherein said spring elements each are one of a spring packet and an adjusting packet and said spring packet and said adjusting packet are detachably connected at ends thereof with chock guide elements guiding the broke chocks.
  • 2. The braking device according to claim 1 wherein said spring packet and said adjusting packet are C-shaped.
  • 3. The braking device according to claim 1 wherein said spring packet is arranged at a support body that acts on said chock guide elements.
  • 4. The braking device according to claim 3 wherein said support body has an associated groove formed therein for reception of each said spring packet.
  • 5. A braking device for an elevator with an elevator car and a counterweight that are movable along guide rails in an elevator shaft, wherein the braking device is arranged at the elevator car or at the counterweight and in the case of excess speed stops the elevator car or the counterweight at the guide rails with spring elements and brake chokes, wherein the spring elements are of modular construction and generate different braking forces, comprising: a plurality of spring elements constructed from lamellae producible in a simple manner, each of said spring elements being one of a spring packet and an adjusting packet, each said spring packet being arranged at a support body that acts on chock guide elements guiding the brake chocks.
  • 6. The braking device according to claim 5 wherein said spring elements are C-shaped.
  • 7. The braking device according to claim 5 wherein said spring elements are detachably connected at ends with chock guide elements guiding the brake chocks.
  • 8. The braking device according to claim 5 wherein said support body has an associated groove formed therein for receiving each of said spring packets.
  • 9. The braking device for attachment to one of an elevator car and a counterweight that are movable along guide rails in an elevator shaft, wherein the braking device is actuated to engage a guide rail in the case of excess speed, comprising:a housing; a pair of brake chocks mounted on said housing and movable from a disengaged position to a guide rail engaging position; and at least one spring packet mounted on said housing and having opposed ends connected to associated ones of said brake chocks, said at least one spring packet being of modular construction having lamellae selected to produce a predetermined braking force, and including at least one adjusting packet mounted on said housing and having opposed ends connected to an associated one of said brake chocks.
  • 10. The braking device according to claim 9 wherein each end of said spring packet is detachably connected to said associated brake chock by a spring bracket.
Priority Claims (1)
Number Date Country Kind
00810452 May 2000 EP
Parent Case Info

This application is a continuation of PCT/01/00316 filed on May 23, 2001.

US Referenced Citations (11)
Number Name Date Kind
3155199 Bricker Nov 1964 A
4538706 Koppensteiner Sep 1985 A
5363942 Osada Nov 1994 A
5370208 De Jong Dec 1994 A
5782319 Woodruff et al. Jul 1998 A
5819879 Lang et al. Oct 1998 A
5964320 Kato et al. Oct 1999 A
5964322 Thompson et al. Oct 1999 A
6092630 Wendel et al. Jul 2000 A
6260673 Mustalahti Jul 2001 B1
6325184 Lujan Dec 2001 B1
Foreign Referenced Citations (4)
Number Date Country
0 957 059 Nov 1999 EP
62-74896 Apr 1987 JP
11011818 Jan 1999 JP
2000302351 Oct 2000 JP
Continuations (1)
Number Date Country
Parent PCT/CH01/00316 May 2001 US
Child 10/303624 US