Brake device for a travel body of an elevator system

Abstract

A brake device for an elevator system with a travel body movable in an elevator shaft along a guide and/or brake rail brakes and retains the travel body on the rail as required. The brake device includes a control plate receiving a brake body and for positioning the brake body relative to the rail. The brake body has first and second brake elements pivoted about a common axis. The first brake element is for braking and retaining purposes when the travel body is moving along the rail in an upward direction, and the second brake element is for braking and retaining purposes when the travel body is moving along the rail in a downward direction.

Claims

1. A safety brake for an elevator installation with a travel body movable along at least one of a guide rail and a brake rail in an elevator shaft, wherein the safety brake brakes and fixes the travel body at the rail when required, the safety brake comprising: a brake body having a first brake element and a second brake element, wherein the first and second brake elements are movable independently of one another and the first brake element is for braking and fixing only in case of movement of the travel body along the rail in an upward direction and wherein the second brake element is for braking and fixing only in case of movement of the travel body along the rail in a downward direction an axle arranged at the brake body, the first brake element and the second brake element being pivotable about the axle; and wherein the first brake element and the second brake element are coupled together to be freely rotatable about the axle relative to one another within a predetermined displacement angle.

2. The safety brake according to claim 1 wherein one of the first brake element and the second brake element includes an entrainer that projects into an entraining guide formed in another one of the first and second brake elements to enable the first and second brake elements to freely rotate relative to one another through the predetermined displacement angle.

3. The safety brake according to claim 1 including a control plate for positioning the brake body relative to the rail, wherein the control plate is positionable in each of a rest position and a braking position by at least one of a linear movement and a pivot movement, wherein the control plate is held in the rest position by an electromagnet that is switched on, and wherein the electromagnet is switched off to enable the control plate to move into the braking position by a compression spring.

4. The safety brake according to claim 3 wherein the axle is arranged at a support and the control plate is arranged at the support for linear or pivotal movement to position the first brake element and the second brake element relative to the rail, wherein the first brake element and the second brake element are pivotable from a basic position to a first braking position where the first brake element and the second brake element are in contact with the rail.

5. The safety brake according to claim 4 wherein each of the first brake element and the second brake element are pivotable by friction couple with the rail from the first braking position to a second braking position and the control plate is movable from the braking position to the rest position by pivotation of the first brake element or the second brake element from the first braking position to the second braking position.

6. The safety brake according to claim 5 wherein the first brake element and the second brake element are coupled together to be freely rotatable about the axle relative to one another within a predetermined displacement angle, wherein the first brake element entrains the second brake element or the second brake element entrains the first brake element after pivotation through the predetermined displacement angle, and wherein the entrained one of the first and second brake elements is rotated back into the basic position and the control plate thereby moves from the braking position back into the rest position.

7. The safety brake according to claim 3 wherein the control plate has a first control dog that activates the first brake element and a second control dog that activates the second brake element.

8. The safety brake according to claim 3 including a sensor for at least one of position monitoring and state monitoring of at least one of the first brake element, the second brake element and the control plate.

9. The safety brake according to claim 3 wherein at least one of the first brake element and the second brake element is biased toward the control plate by at least one spring.

10. The safety brake according to claim 1 wherein at least one of the first and second brake elements is formed as an eccentric disc.

11. The safety brake according to claim 10 wherein the eccentric disc is curved in a section on a side facing the rail, the section being in contact with the rail in a first braking position of the eccentric disc, and the eccentric disc is planar in another section on the side facing the rail, the another section being in contact with the rail in a second braking position of the eccentric disc.

12. The safety brake according to claim 11 wherein the first braking area is at most 60% of the second braking area.

13. The safety brake according to claim 1 wherein the first brake element has a first braking area smaller than a second braking area of the second brake element.

14. The safety brake according to claim 13 wherein the first braking area is at most 75% of the second braking area.

15. The safety brake according to claim 13 wherein the second brake element includes two eccentric discs with a same braking area, wherein the first braking area of the first brake element is equal to the braking area of one of the eccentric discs, and wherein the first brake element is arranged between the two eccentric discs of the second brake element.

16. The safety brake according to claim 1 including a sensor for at least one of position monitoring and state monitoring of at least one of the first brake element and the second brake element.

17. An elevator installation having a travel body and a safety brake according to claim 1 arranged at the travel body.

Description

DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the invention are explained in more detail in the following by way of embodiments for better understanding and without restricting the invention to the embodiments, wherein:

(2) FIG. 1 shows a schematic illustration of an elevator installation with a safety brake according to the invention;

(3) FIGS. 2 to 7 show schematic illustrations of a safety brake according to the invention in sequential operational states;

(4) FIG. 8 shows a sectional side view of a brake body of the safety brake according to the invention;

(5) FIGS. 9 to 12 show perspective views of an embodiment of a safety brake according to the invention in sequential operational states; and

(6) FIG. 13 shows a front view of the safety brake according to FIG. 12.

DETAILED DESCRIPTION

(7) An elevator installation 2 with a travel body 3 comprising a safety brake 1 according to the invention for braking and fixing the travel body 3 when required is shown in FIG. 1 in schematic illustration. The elevator installation 2 comprises an elevator shaft 5 in which a guide rail 4 is arranged, along which the travel body 3 is movable in an upward direction a or a downward direction b. The travel body 3 is suspended in the elevator shaft 5 by means of support equipment 16 formed by cables. Movement of the travel body 3 in the upward direction a and/or the downward direction b is possible by means of a drive 15, which is in operative connection with the travel body 3 by way of the support equipment 16. In the case of the illustrated elevator installation 2 the travel body 3, frequently an elevator car, is supported to the full extent by the drive 15. As a rule, a further travel body, in the form of a counterweight, is disposed in the elevator shaft, which moves oppositely to the travel body 3 and which is correspondingly fastened to the opposite end of the support equipment 16.

(8) The safety brake 1 mounted on the travel body 3 is constructed so that when required, such as, for example, a failure of the support equipment 16 or in the case of power failure, the travel body can be braked and fixed. For this purpose a braking action is achieved by the safety brake 1 in interaction with the guide rail 4. The guide rail 4 can, in a given case, also be constructed as a brake rail. Alternatively, the arrangement of a brake rail additionally to the guide rail is also conceivable in order to, for example, brake the travel body 3 only in specific sections in the elevator shaft 5 by means of the safety brake 1. A sensor 12 for position monitoring and/or state monitoring of the safety brake 1 is arranged at the safety brake 1. The braking action of the safety brake 1 can, for example, be compared by the sensor 12 with a target value, whereby a state monitoring of the safety brake can be achieved. The sensor 12 can obviously also be arranged at a different location on the travel body. The sensor 12 can also be merely a switching element which monitors a working setting of the safety brake and, for example, stops the elevator installation if the safety brake is actuated.

(9) From here on and in the following, the same reference numerals are used for the same features in all figures and accordingly are explained again only when required.

(10) A side view of the safety brake 1 according to the invention is schematically illustrated in FIGS. 2 to 7 in sequentially successive operational states. For better understanding, the safety brake 1 is illustrated in co-operation with the guide rail 4, although the guide rail 4 is not a component of the safety brake 1.

(11) The safety brake 1 comprises a support 22. The support 22 forms a housing-like load-bearing structure for absorption of clamping forces of the safety brake device. An axle 9 is fixedly arranged in the support 22. In addition, the safety brake 1 includes a two-level brake body, comprising a first brake element 7 and a second brake element 8. The two brake elements are constructed as eccentric discs and pivotably arranged on the common axle 9. A control plate 6 is arranged in or at the support 22 to be displaceable between a rest position r and a braking position e. The control plate 6 has a surface 19 as an outer contact area. The surface 19 interacts with the brake elements 7, 8. In addition, an electromagnet 17 and compression springs 18 are arranged in the support 22. The electromagnet 17 holds the control plate 6 in the rest position r against a force of the compression springs 18. Moreover, a spring 23 resiliently draws the second brake element 8 against the control plate 6 or against the surface 19 of the control plate 6. The second brake element 8 is thus disposed in the basic position g. Analogously, the first brake element 7 is held by a spring (not illustrated) in the basic position g.

(12) A counter-braking body 13 is arranged on or in the support 22 on the side of the guide rail 4 remote from the first and second brake elements 7, 8. The counter-braking body 13 is supported in the support 22 by means of plate springs 14 and can be pressed against the guide rail 4 so that a braking action is achievable by the safety brake 1. A pressing force of the brake body 13 against the guide rail 4 is settable by, for example, selection of the bias of the plate springs.

(13) The first brake element 7 has a first braking area 10 and is disposed in the basic position g. The second brake element 8 has a second braking area 11 and is similarly disposed in the basic position g. The braking area 11 is larger than the braking area 10, which, however, is not evident in FIGS. 2 to 6.

(14) The arrow denoted by b characterizes the relative movement between the travel body, at which the safety brake 1 is arranged, and the guide rail 4. The travel body is moved in downward direction b, which is illustrated in FIGS. 2 to 6 as movement of the guide rail 4. Thus, a co-ordinate system fixed relative to the safety brake 1 has been selected.

(15) The control plate 6 is disposed in FIG. 2 in the rest position r and is held by means of the electromagnet 17, which can be switched off, in the rest position r. In addition, arranged at the control plate 6 are the compression springs 18 by means of which after switching-off of the electromagnet 17 the control plate 6 is movable into a braking position s (shown in FIG. 3). The braking elements 7, 8 and also the counter-braking body 13 have a gap relative to the guide rail 4 so that the travel body is freely movable along the guide rails.

(16) The safety brake 1 is illustrated in FIG. 3 in a first operating state in which the electromagnet 17 is switched off and the control plate 6 has been brought by means of the compression springs 18 into the braking position e. Through co-operation of the wedge-shaped surface sections of the surface 19 of the control plate 6 and a rear-side shape of the first brake element 7 and the second brake element 8 the two brake elements 7, 8 are pivoted in opposite directions about the axle 9. A respective curved region of each of the brake elements 7, 8, which are constructed as eccentric discs, is thereby brought into contact with the guide rail 4. The two brake elements 7, 8 are now disposed in a first braking position s. They are pressed against the guide rails by a pressing force determined by the compression springs 18.

(17) As illustrated in FIG. 4, one of the two brake elements 7, 8 is further pivoted through the contact between guide rail 4 and two brake elements 7, 8 by means of friction couple by way of the relative movement of the guide rail 4. In the example, depending on the direction of the relative movement the second brake element 8 is further pivoted. In that case due to the shape of the brake elements similar to eccentrics the first brake element 7 loses contact with the guide rail 4 and it is drawn back by its spring (not illustrated) towards the control plate. Due to the shape and arrangement of the second brake element 8 and the surface 19 of the control plate 6 the control plate 6 is simultaneously moved back in direction u into the rest position e.

(18) In FIG. 5 the pivotation of the second brake element into a second braking position z is concluded, whereby the second braking area 11 has been brought into contact with the guide rail 4. The brake element 8 has during the clamping in the second braking position z drawn the support 22 together with the counter-braking lining 13 towards the guide rail and stressed the plate springs 14 so that a desired braking force could be built up. The brake elements 7, 8 are preferably provided with end abutments relative to the support 22 so that further rotation of the brake elements 7, 8 on reaching the second braking position z is prevented.

(19) In addition, during the clamping of the second brake element 8 in the second braking position z the control plate 6 was moved into the rest position r and is again in contact with the electromagnet 17. The compression springs 18 are biased again. The electromagnet 17 is arranged to be yielding substantially parallel to the action of the restoring force u so that bridging-over is made possible in order to guarantee contact between control plate 6 and electromagnet 17 during resetting.

(20) As illustrated in FIG. 6, after braking or fixing of the travel body by means of the safety brake 1 the travel body is moved in an upward direction a, which is also here illustrated by a movement of the guide rail 4. As a result, resetting of the second brake element 8 into the first brake position s and thus release of the safety brake 1 take place. The electromagnet 17 is switched on at the latest on reaching the first braking position s or, better, already beforehand so as to hold the control plate in the rest position r.

(21) As illustrated in FIG. 7, the second braking element 8 is pivoted back into the basic position g, which can be achieved by the spring 23. The safety brake is again reset into its original position in correspondence with FIG. 2.

(22) A detail of the safety brake 1 is illustrated in FIG. 8 in a sectional illustration through the axle. The axle 9 is executed as a component of the support 22. In addition, the first brake element 7 and the second brake element 8 are again arranged at the axle 9. The two brake elements 7, 8 are mounted, multi-level, on the axle 9 by means of a fastening disc 21. The first brake element 7 has a first braking area 10, which is approximately 50% of the second braking area 11 of the second brake element 8. The first brake element 7 is arranged between the two brake parts of the second brake element 8. The brake parts all have a thickness w of 9 to 12 millimeters. The axle 9 is dimensioned in order to take over the clamping forces arising on clamping of the brake element 7, 8 in the second braking position.

(23) The safety brake 1 additionally comprises slide bearings 20, by means of which the brake elements are pivotable as described in the foregoing.

(24) A further detailed embodiment of a safety brake 1 according to the invention is illustrated again in sequentially successive operational states in FIGS. 9 to 12. Equivalent parts are also provided in these figures with the same reference numerals as were used in the preceding figures. The safety brake 1 is illustrated in the figures without guide rail 4. The safety brake 1 again comprises the support 22, which forms the housing of the safety brake and which is designed to transmit resultant braking forces to the travel body of the elevator installation. The support 22 is of multi-part construction in the example. Arranged at the support 22 is the axle 9 serving for mounting of the first brake element 7 and the second brake element 8. The two brake elements 7, 8 are pivotably mounted on the axle 9 by way of suitable bearing elements, preferably a slide bearing bush, and secured against slipping laterally. The two brake elements are arranged parallel and adjacent to one another. In this embodiment the first brake element 7 includes a curved recess forming an entraining guide 25. An entrainer 26, which is in the form of a pin and which protrudes into the entraining guide 25 of the first brake element, is arranged in the second brake element 8. In the example the entraining guide 25 is so dimensioned that the two brake elements can be rotated relative to one another through an appropriately predetermined displacement angle 27 of approximately plus/minus 90 degrees. The size of the predetermined displacement angle 27 results from the design of the brake elements 7, 8. In the present case a rotational angle of the brake elements 7, 8 from the basic position g to the second braking position z is approximately 90 degrees, whereby also the size of the predetermined displacement angle 27 is determined. The two brake elements 7, 8 are drawn by a spring mechanism (not illustrated) towards the control plate 6. The control plate 6 includes a first control dog 67, which co-operates with a back surface of the first brake element 7, and it includes a second control dog 68, which co-operates with a back surface of the second brake element 8. The control plate 6 is held by the electromagnets 17 in the rest position r by way of a corresponding magnet retaining plate 17.1 against the force of the compression springs 18. The sensor 12, in the form of a switch, monitors the rest position of the control plates 6 and thus an operational state of the safety brake.

(25) The counter-braking body 13 is arranged on the side of the safety brake opposite the first and second brake elements 7, 8 on or in the support 22 again analogously to the preceding solution. The counter-braking body 13 is supported in the support 22 by means of plate springs 14. The guide rail 4 can be arranged and pressed between brake elements 7, 8 and the counter-braking body 13 so that a corresponding braking action by the safety brake 1 is achievable. The pressing force of the brake body 13 against the guide rail 4 is in that case settable by, for example, selection and setting of the bias of the plate springs.

(26) In FIG. 9 the control plate 6 is disposed in its rest position r. The electromagnet is energized. The first brake element 7 is drawn by means of a spring mechanism (not illustrated) against the control dog 67 and the second brake element 8 is correspondingly drawn towards the control dog 68. The brake elements 7, 8 and the entire safety brake 1 are disposed in a basic position g so that the travel body would be freely movable along the guide rails. A gap relative to the counter-braking body 13 is appropriately large so that the guide rail can be arranged to be freely movable.

(27) In FIG. 10 the electromagnet is switched to be free of current and the compression spring 18 urges the control cam 6 in the direction of the brake elements 7, 8. The first control dog 67 thereby rotates the first brake element 7 from the basic position g into the first braking position s and at the same time the second control dog 68 rotates the second brake element 8 from the basic position g into the first braking position s thereof. The rotation takes place until the brake elements 7, 8 have been rotated to such an extent that they can clamp the guide rail. The sensor 12 detects the adjustment of the control plate 6 and can give an appropriate signal to a control of the elevator.

(28) Due to the clamping of the brake elements 7, 8, in the case of an assumed downward movement of the safety brake in relation to a guide rail the first brake element 7 as apparent in FIG. 11 is now further rotated in counter-clockwise direction and it increasingly clamps the safety brake due to its preferably eccentric shape. The second brake element 8 remains in its first braking position s and slips over the travel path. The further rotation of the first brake element 7 takes place until in an intermediate position of the rotational angle between the two brake elements 7, 8 the predetermined displacement angle 27, which is determined by the co-operation of the entrainer 26 and the entraining guide 25, is reached. This state is apparent in FIG. 11.

(29) Through the further movement of the safety brake obviously the first brake element 7 is further rotated as illustrated in FIG. 12 until its substantially planar surface, which is formed as a braking surface, bears against the guide rail. The maximum working point or the second braking position z of the first brake element 7 is thus reached. In FIG. 13, which illustrates a front view of the safety brake in the working position according to FIG. 12, a gap between mating brake lining 13 and the brake surface of the first brake element is, as apparent, minimal. This means that a guide rail, which would be arranged in this intermediate space, would be clamped to the maximum extent as explained in the preceding FIGS. 2 to 7.

(30) As apparent in FIGS. 12 and 13, the first brake element 7 entrains the second brake element 8 by means of entrainer 25 and entrainer guide 26 and rotates this back into the original basic position g. A rear side of the second brake element in that case urges the control plate 6 into its position corresponding with the rest position r. Whilst as a consequence the first brake element 7 by its clamping action relative to the guide rail and mating brake lining produces braking of the travel body, the control plate 6 is already brought by the electromagnet 17 into a position corresponding with the rest position r.

(31) For resetting of the safety brake merely the electromagnet 17 can now be energized again and the safety brake 1 can be reset in a return movement as was explained in connection with FIG. 6.

(32) The functions were explained in the preceding examples on the basis of one travel direction. Obviously the functional sequence is analogous for an opposite travel direction. Variations of plots of braking force are possible by different shaping of the brake elements 7, 8 in the form of eccentric discs or obviously the brake elements 7, 8 can be varied as explained, for example, in connection with FIG. 8.

(33) Further details apparent in FIGS. 9 to 13 such as, for example, sealing devices for securing settings of the plate springs 14 correspond with usual forms of embodiment of safety brakes and are not further explained.

(34) 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.