Safety brake device for an elevator installation

Abstract

A safety brake device at a load receiving component of an elevator installation includes brake equipment that co-operates with a guide rail of the load receiving component. The brake equipment includes a cam disc that is rotatable about a cam disc axis and for activation of the safety brake device is set into a rotation through an activation rotational angle by an activating mechanism, wherein as a consequence of such rotation the cam disc comes into contact with the guide rail, whereby the guide rail moving relative to the safety brake device when the load receiving component is travelling rotates the cam disc into a position in which the brake equipment and thus the safety brake device produce an intended braking action relative to the guide rail. The activating mechanism includes a pivotally mounted activating lever driven by an activating spring to rotate the cam disc.

Claims

1. A safety brake device for a load receiving component of an elevator installation, the safety brake device comprising: brake equipment, the brake equipment being configured to work with a guide rail for the load receiving component, the brake equipment comprising a cam disc rotatable about a cam disc axis; and an electrically controlled activating mechanism, the activating mechanism being configured to activate the safety brake device by rotating the cam disc through an activation rotational angle such that the cam disc contacts the guide rail, the activating mechanism comprising a pivotably mounted activating lever and an activating spring, the activating spring directly causing a pivot movement of the activating lever prior to contact of the cam disc with the guide rail, the activating lever being fixed in an initial position in a first operating state of the safety brake device and the activating lever being pivotally driven by the activating spring from the initial position to an end position when the activating mechanism is released in a second operating state of the safety brake device, the activating lever being coupled with the cam disc such that the pivot movement of the activating lever from the initial position toward the end position rotates the cam disc through the activation rotational angle.

2. The safety brake device according to claim 1, the electrically controlled activating mechanism further comprising an electromagnet, the activating lever being fixable in the initial position by activating the electromagnet, the activating lever being releasable by deactivating the electromagnet for moving the activating lever toward the end position.

3. The safety brake device according to claim 2, the activating lever being configured to rotate the cam disc when the electromagnet is deactivated, where contact between the cam disc and the guide rail further rotates the cam disc.

4. The safety brake device according to claim 1, the cam disc comprising: a periphery with a flat surface; and a peripheral section adjoining the flat surface, the peripheral section having a radius increasing with rotational angle.

5. The safety brake device according to claim 4, the cam disc further comprising a cylindrical projection, the cylindrical projection eccentrically arranged with respect to the axis of rotation of the cam disc, the cylindrical projection comprising a convex outer surface receivable by a concave inner surface of a first brake element.

6. The safety brake device according to claim 5, further comprising a second brake element, the second brake element including a concave inner surface that cooperates with a convex peripheral outer surface of the cylindrical projection, the second brake element including a cut-out through which the periphery of the cam disc protrudes.

7. The safety brake device according to claim 6, the second brake element comprising a straight, tangential peripheral section of the peripheral section of the cam disc.

8. The safety brake device according to claim 1, the safety brake device being displaceable in the load receiving component or in a support frame of the load receiving component.

9. The safety brake device according to claim 8, further comprising a lever abutment, the lever abutment being configured to move the activating lever into a resetting position when the load receiving component is raised for resetting the safety brake device.

10. The safety brake device according to claim 1, further comprising a switch activatable by the pivot movement of the activating lever or by rotation of the cam disc.

11. The safety brake device according to claim 1, the activating lever being a first activating lever, the first activating lever being connected by a shaft to a second activating lever, the second activating lever being part of another safety brake device.

12. The safety brake device according to claim 1 being arranged on the load receiving component.

13. The safety brake device according to claim 1, wherein the activating spring is a torsion spring.

14. A safety brake device method, comprising: retaining an activating lever of a safety brake device in an initial position using an activated electromagnet; directly pivoting the activating lever from the initial position toward an end position using an activating spring and by deactivating the electromagnet; rotating a rotatably mounted cam disc using the pivoting activating lever; moving a periphery of the cam disc into contact with a guide rail, the guide rail moving relative to the safety brake device; and further rotating the cam disc using the guide rail, wherein a peripheral section of the cam disc having an increasing radius rolls on the guide rail, the cam disc and a brake element of brake equipment being pressed against the guide rail and braking a load receiving component.

15. The method according to claim 14, further comprising resetting the safety brake device, the resetting comprising, moving the load receiving component relative to the brake equipment, the brake equipment being fixedly seated on the guide rail, the moving being limited by an upper abutment and a lower abutment, as a result of the moving the load receiving component and using a lever abutment, pivoting the activating lever against the activating spring into a resetting position, and activating the electromagnet.

16. The method according to claim 15, further comprising: pressing the lower abutment against the brake equipment; and releasing the cam disc from against the guide rail.

17. The method according to claim 14, wherein the activating spring is a torsion spring.

18. A safety brake device for a load receiving component of an elevator installation, the safety brake device comprising: brake equipment for connecting the load receiving component with a guide rail by friction couple, the brake equipment comprising a cam disc rotatable about a cam disc axis; and an electrically controlled activating mechanism for activating the safety brake device by rotating the cam disc through an activation rotational angle such that the cam disc contacts the guide rail, the activating mechanism comprising a pivotably mounted activating lever and an activating spring, the activating spring directly causing a pivot movement of the activating lever prior to contact of the cam disc with the guide rail, the activating lever being fixable in an initial position and being pivotally driven by the activating spring, the activating lever being movable from the initial position toward an end position when the activating mechanism is released, the activating lever being coupled with the cam disc such that the pivot movement of the activating lever from the initial position toward the end position rotates the cam disc through the activation rotational angle.

19. The safety brake device according to claim 18, the electrically controlled activating mechanism further comprising an electromagnet, the activating lever being fixable in the initial position by activating the electromagnet, the activating lever being releasable by deactivating the electromagnet for moving the activating lever toward the end position.

20. The safety brake device according to claim 19, the activating lever being configured to rotate the cam disc when the electromagnet is deactivated, where contact between the cam disc and the guide rail further rotates the cam disc.

21. The safety brake device according to claim 18, the cam disc comprising a periphery with a flat surface and a peripheral section adjoining the flat surface, the peripheral section having a radius increasing with rotational angle.

22. The safety brake device according to claim 21, the cam disc further comprising a cylindrical projection, the cylindrical projection eccentrically arranged with respect to the axis of rotation of the cam disc, the cylindrical projection comprising a convex outer surface receivable by a concave inner surface of a first brake element.

23. The safety brake device according to claim 18, wherein the activating spring is a torsion spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure is explained in more detail in the following by way of example on the basis of figures. The figures are described conjunctively and generally. The same reference numerals denote equivalent or the same device parts and reference numerals with different indices indicate functionally equivalent or similar, but separate, device parts even, when they are identical with others, but are arranged at a different location or in another variant of embodiment are a part of another overall function.

(2) In that case:

(3) FIG. 1 shows a schematic illustration of an elevator installation with an arrangement of a speed limiter system according to the prior art;

(4) FIG. 2 shows a schematic and perspective illustration of a first safety brake device in a normal operating state;

(5) FIG. 3 shows the safety brake device of FIG. 2 in a front view and in a second operating state;

(6) FIG. 4 shows the safety brake device of FIGS. 2 and 3 in a state in which the brake equipment has achieved its maximum braking force;

(7) FIG. 5 shows the safety brake device of FIGS. 2 to 4, similarly in a front view, in the case of resetting;

(8) FIG. 6 shows a side view of the safety brake device of FIGS. 2 to 5;

(9) FIG. 7 shows a front view of a second variant of embodiment of a safety brake device with brake elements set at an inclination;

(10) FIG. 8 shows a variant of a cam disc with integrated brake element in its normal position;

(11) FIG. 9 shows the cam disc according to FIG. 8 in its braking position; and

(12) FIG. 10 shows a further form of embodiment of a safety brake device.

DETAILED DESCRIPTION

(13) FIG. 1 shows an elevator installation 100 such as is known from the prior art. A load receiving means or an elevator cage 2 is arranged in an elevator shaft 1 to be movable and is connected by way of a support means 3 with a similarly movable counterweight 4. The support means 3 is, in operation, driven by a drive pulley 5 of a drive unit 6 which is arranged in the uppermost region of the elevator shaft 1 in an engine room 12. The elevator cage 2 and the counterweight 4 are guided by means of guide rails 7a or 7b and 7c extending over the shaft height.

(14) The elevator cage 2 can serve an uppermost story 8, further stories 9 and 10 and a lowermost story 11 and thus describe a maximum travel path S_M. The elevator shaft 1 is formed from shaft side walls 15a and 15b, a shaft ceiling 13 and a shaft floor 14, on which a shaft floor buffer 16a for the counterweight 4 and two shaft floor buffers 16b and 16c for the elevator cage 2 are arranged.

(15) The elevator installation 100 further comprises a speed limiter system 200. This in turn comprises a speed limiter 17 with a cable pulley 18 fixedly connected with a cam disc 19. The cable pulley 18 and the cam disc 19 are driven by way of a limiter cable 20, because the limiter cable 20 conjunctively describes the respective upward or downward movements of the elevator cage 2 by virtue of a fixed connection in the form of a cable coupling 21 connected with the load receiving means. The limiter cable 20 is for that purpose guided as an endless loop over a tensioning roller 22 which can be tensioned by a tensioning lever 23 in that the tensioning lever 23 is rotatably mounted in a rotary bearing 24 and a weight 25 is displaceably arranged on the tensioning lever 23.

(16) The speed limiter 17 further comprises a pendulum 26 which is arranged at an axle 27 to be pivotable in both directions of rotation. Arranged at one side of the pendulum 26 is a roller 28 which is drawn by a resetting spring (not illustrated in more detail in this figure) against the rises of the cam disc 19.

(17) As a first safety step the speed limiter system 200 provides that in the case of attaining a first excess speed VCK the roller 28 can no longer run completely through the valleys between the rises of the cam disc 19 and thus the pendulum 26 begins to rise up in counter-clockwise sense. This rising movement activates a pre-contact switch 29 which electrically switches off and stops the drive unit 6 by way of a control line 30 and by way of a control 31. The control 31 is connected with a control device 63 for the entire elevator installation 100, into which all control signals and sensor data flow in common.

(18) As a second, purely mechanical safety step the speed limiter system 200 provides that on reaching a second, higher excess speed VCA the pendulum 26 rises still further in counter-clockwise sense and thus a pendulum nose 32 engages in recesses or in blocking dogs 33 at the cam disc 19. The cable pulley 18 is thereby blocked and by virtue of the friction between the cable pulley 18 and the limiter cable 20 generates a tension force 34 by means of which an L-shaped double lever 35a is rotated at an articulation point. The approximately horizontal limb of the L-shaped double lever 35a thus activates, by way of an activating rod 37a, a symbolically illustrated safety brake device 38a. The other, approximately vertical limb of the double lever 35a at the same time exerts a thrust force on a connecting rod 39 and a second L-shaped double lever 35b thus rotates about an articulation point 36b. As a result, a further activating rod 37b in turn activates a secondalso only symbolically illustratedsafety brake device 38b. In this way a purely mechanical activation of two mechanically operating safety brake devices 38a and 38b is realized, which in the case of excess speed or an imminent risk situation fixes the elevator cage 2 to the guide rails 7b and 7c.

(19) FIG. 2 shows in a schematic and perspective illustration a form of embodiment of a safety brake device 38c, which is a component of an elevator installation 100a or of a speed limiting or safety system 200a and is arranged in a support frame 40 of a load receiving means 2a. The support frame 40 can also be the support frame of a counterweight. The support frame 40 can also be an integrated component of the load receiving means 2a.

(20) The safety brake device 38c comprises brake equipment 300 and an activating mechanism 400. The brake equipment 300 in turn comprises a brake caliper 41, which is arranged to be displaceable within the support frame 40 not only in vertical direction, but also in horizontal direction, i.e. along both a Z axis and an X axis. In that case the brake caliper when the brake equipment is non-activated is urged in yielding manner, i.e. by means of springs, on the one hand to the right and on the other hand upwardly into a respective abutment position within the support frame 40. A first brake element 42 and a second brake element 43 are arranged in the brake caliper 41 to be displaceable along an adjusting axis X. The adjusting axis X is approximately perpendicular to a longitudinal axis Z of an indicated guide rail 7, the guide web 7d of which protrudes into the intermediate space between the first brake element 42 and the second brake element 43. The first brake element 42 is resiliently supported relative to the brake caliper 41 in the direction of the X axis, preferably by means of biased plate-spring packets 44a and 44b.

(21) The activating mechanism 400 of the safety brake device comprises an electromagnet 45, which is possibly mounted by means of a spring mounting 46 to be yielding. Moreover, the activating mechanism 400 comprises an activating lever 47 which is pivotably mounted in a pivot bearing 48 and thus forms a left-hand arm 49a and a right-hand arm 49b. Arranged behind the left-hand arm 49a is a switch 50 which stops the drive of the elevator installation 100a as soon as the activating lever 47 is pivoted out in counter-clockwise sense in a pivot direction 51 due to power interruption of the electromagnet 45. The power interruption of the electromagnet 45 takes place possibly through an electronic speed limiter (not illustrated in more detail). The activating lever 47 can include a first activating lever 47 and a second activating lever 76, where the first activating lever 47 is connected to the second activating lever 76 by a shaft 77, and the second activating lever 76 can be part of another safety brake device 38c.

(22) The pivotation of the activating lever 47 out of an initial position P.sub.I in the pivot direction 51 is driven by an activating spring 52, which in the case of the illustrated embodiment of the safety brake device is constructed as a torsion spring. The right-hand arm 49b of the activating lever 47 has a dovetail-like end with a contact surface 53, which contact surface co-operates with an entrainer 54 arranged at a cam disc 55. The cam disc is rotatably mounted in a rotary bearing 56. The outward pivotation of the activating lever 47 in the pivot direction 51 produces rotation of the cam disc 55 through an activation rotational angle in a rotational direction 57 directed in counter-clockwise sense.

(23) The cam disc 55 has on at least one side a cylindrical projection 58 which is arranged eccentrically with respect to the axis of rotation of the cam disc and this cylindrical projection 58 in turn has a convex peripheral outer surface 59, which co-operates with a concave inner surface 60 in the second brake element 43. The rotation of the cam disc 55 thus produces a displacement of the second brake element 43, which displacement also includes a component in the direction of the adjusting axis X. Through the rotation of the cam disc 55 the second brake element is thus moved against the guide web 7d of the guide rail 7.

(24) It can be seen that the second brake element 43 has a cut-out 61, through which a peripheral surface 62 of the cam disc 55 protrudes. The safety brake device 38c is disposed, in the arrangement illustrated in FIG. 2, in a first operating state P.sub.1 which corresponds with the normal operating state in which the safety brake device is disposed in normal operation of the elevator installation 100a. The brake elements 42 and 43 are spaced from the guide web 70 of the guide rail 7c. In addition, the peripheral surface 62 of the cam disc 55 is spaced from the guide web 7d of the guide rail 7c, since it has a flat 63 which in this first operating state P.sub.1 is oriented parallel to the guide rail 7. The cam disc 55 is thereby resiliently held by a restraining spring 64 in a normal position. In this first operating state P.sub.1 the activating lever 47 is held in its initial position P.sub.I by the electromagnet 45 against the force of the activating spring 52, which in the present example is constructed as a torsion spring.

(25) A second operating state P.sub.2 is illustrated in FIG. 3, in which after detection of a safetybraking situation the electromagnet 45 has released the activating lever 47 and the activating lever has been pivoted out of its initial position in counter-clockwise sense in the pivot direction 51 by the activating spring 52. The entrainer 54 of the cam disc 55 is just still in contact with a first contact surface 53 in the end region of the activating lever 47 and the cam disc 55 has been rotated in the rotational direction 57 through the activation rotational angle so that a peripheral section 65, which adjoins the flat 63 and increases in radius, of the cam disc has come into contact with the guide web 7d of the guide rail 7.

(26) The safety brake device 38c, particularly the activating lever 47 and the cam disc 55, are disposed in the second operating state P.sub.2 in which further rotation of the cam disc 55 no longer depends on a movement of the activating lever 47, since as a consequence of the contact of the peripheral section 65, which increases in radius, of the cam disc 55 with the guide rail 7 and the upward movement 67, which is present, of the guide rail 7 relative to the cam disc further rotation of the cam disc is produced. The restraining spring 64 ensuring the normal position of the cam disc in normal operation is in that case stretched. Rolling of the peripheral section 65, which increases in radius, on the guide rail 7 produces a displacement of the entire brake caliper 41 or of the entire brake equipment 300 relative to the guide rail, wherein initially the first brake element 42 comes to bear against the guide web 7d of the guide rail 7 and subsequently the plate-spring packets 44a, 44b are increasingly compressed. Resulting from the compression of the plate-spring packets are increasing pressing forces not only between the cam disc 55 and the guide web 7d of the guide rail, but also between the first brake element 42 and the guide web 7d. The convex peripheral outer surface 59 of the cylindrical projection 58 eccentrically connected with the cam disc 55 has still not brought the brake element 43 to bear against the guide web 7d of the guide rail 7.

(27) FIG. 4 shows the safety brake device 38c in a state in which the brake equipment 300 has reached its maximum braking force. Due to the pressing of the cam disc 55 against the guide web 7d of the guide rail 7 and the progressing downward movement 66 of the safety brake device 38c or the progressing relative upward movement 67 of the guide rail 7 a further rotation of the cam disc 55 and thus a further rolling of its peripheral section 65, which increases in radius, on the guide rail have taken place. As a consequence, the brake caliper 41 has displaced a corresponding distance to the left, whereby the plate-spring packets 44a, 44b were more strongly compressed and the pressing forces between the cam disc 55 and the guide web 7d as well as between the first brake element 42 and the guide web were further increased. In the course of this process the eccentricity of the cylindrical projection 58 of the cam disc has the effect that the second brake element 43 now bears fully against the guide web 7d of the guide rail 7 and a pressing force between the second brake element 43 and the guide web 7d has built up. The reaction force to this pressing force has in that case acted on the cam disc 55 by way of the cylindrical projection 58 in such a manner that it has counteracted the pressing force between the cam disc and the guide web 7d. After activation of the brake equipment 300 the cam disc 55 has thus rotated until the reaction force to the pressing force of the second brake element 43 has reduced the pressing force between the cam disc 55 and the guide web 7d to such an extent that the residual friction between cam disc 55 and guide web 7d is no longer sufficient for further rotation of the cam disc. If in the case of an actual safety-braking situation this state of the safety brake device has been reached the cam disc together with the two brake elements slides on the guide web until the braking forces built up in the described process have brought the load receiving means to a standstill.

(28) It is apparent from FIGS. 2, 3 and 4 that the brake equipment 300, which substantially comprises the brake caliper 41, the first brake element with the plate-spring packets 44a, 44b, the second brake element 43 and the cam disc 55, is constructed as a unit displaceable in the support frame 40 also in vertical direction. For that purpose the brake equipment is guided in vertically arranged slots 71a and 71b of the support frame 40 by means of support pins 69a and 69b. A support spring 68, which resiliently supports the brake equipment on the support frame 40, is arranged and biased so that the brake equipment 300 is raised in the direction of the vertical axis Z, to such an extent that the support pins 69a and 69b guided in the slots 71a and 71b hit against the upper ends 70a and 70b of the slots. In this way a relative movement between the brake equipment 300 and the support frame 40 of the load receiving means in vertical direction is made possible, which, as described in the following, helps release the brake equipment 300 fixedly clamped on the guide rail after a safety-braking process and in that case resets the safety brake device into the first operating state P.sub.1, i.e. into its normal operating state.

(29) FIG. 4 also shows the situation of the safety brake device prior to such a resetting process. The activating lever 47 is in that case in its activating position pivoted out of its initial position and no longer has contact with the entrainer 54 of the cam disc 55. The restraining spring 64 serving for yielding positioning of the cam disc in its normal position is stretched to a maximum.

(30) FIG. 5 shows the safety brake device 38c during a resetting process. For resetting of the safety brake device the load receiving means 2a together with its support frame 40 is raised possibly by means of the elevator drive, which has the consequence of a downwardly directed relative movement of the guide rail or the guide rail web 7d with respect to the safety brake device 38c. This has the effect that the entire braking equipment 300, which comprises the brake caliper 41, the first brake element 42 with the plate-spring packets 44a, 44b, the second brake element 43 and the cam disc 55 and which is fixedly clamped on the guide rail web 7d, is downwardly displaced relative to the support frame against the force of the support spring 68. This downward displacement of the brake equipment 300 relative to the support frame 40 is limited in that the support pins 69a and 69b guiding the brake equipment hit the lower abutments 74a and 74b, respectively, of the slots 71a and 71b, respectively, vertically arranged in the support frame 40. Until this hitting takes place the load receiving means moved upwardly by the elevator drive has accumulated a sufficiently large amount of kinetic energy in order to move the brake equipment, which is fixedly clamped on the guide rail web 7d, against its braking force upwardly relative to the guide rail web. Through this relative movement the cam disc 55 is rotated by the guide rail web 7d to such an extent in the rotational direction 78, i.e. counter to the rotational direction occurring on activation of the safety brake device, until the cam disc has reached its normal position which is produced by the restraining spring 64 and in which the cam disc is spaced, due to its flat, from the guide rail web. Through this process not only the pressing forces between the brake elements 42, 43 and the guide rail web are eliminated, but also, as described in the following, the activating lever 47 is reset into its initial position.

(31) The resetting spring 64 is fastened at one end, as apparent in the example according to FIG. 5, to the support frame. Alternatively, this end of the resetting spring 64 can also be fastened to the activating lever 47 or coupled thereto. This can be advantageous, since in the case of activation and subsequent movement of the activating lever 47 a biasing and correspondingly the resetting force of the resetting spring 64 are reduced.

(32) As evident from FIGS. 3 and 4, the activating lever 47 at the end of its activating movement driven by the activating spring 52 is stopped by a lever abutment 75 acting on the right-hand arm 49b. In the case of the form of embodiment illustrated here this lever abutment 75 is connected with the brake equipment 300, which is vertically displaceable relative to the support frame 40, or with the brake caliper 41, whilst the activating lever 47 is rotatably mounted on the support frame 40 by way of the pivot bearing 48. Due to the fact that during the resetting process described in the foregoing in connection with FIG. 5 the support frame and the activating lever 47 mounted thereon have been raised, whilst the brake equipment 300, which is fixedly clamped on the guide rail web 7d, and the lever abutment 75 fastened thereto have moved downwardly relative to the support frame, the lever abutment 75 during this resetting process exerts a force, which acts in the resetting direction R.sub.R, on the right-hand arm 49b of the activating lever 47. A torque directed in the resetting pivot direction Sch.sub.R derived from this force has arisen in the activating lever and has moved the activating lever into a resetting position P.sub.R against the action of the activating spring 52, in which position the electromagnet 45 resiliently mounted in upward direction has again picked up the activating lever 47 by switching-on of the magnetization current and subsequently fixed it in the initial position P.sub.I of the activating lever.

(33) A side view of the safety brake device 38c illustrated in FIGS. 2 to 5 is shown in FIG. 6. The arrangement of the support pin 69b guided in the slot 71b of the support frame 40 is, for example, readily recognizable therein. Moreover, it is readily apparent that the brake caliper 41 is also guided by a guide 79 during description of an upward/downward movement 80. The plate-spring packets 44a and 44b are possibly secured in common by way of a securing means 81.

(34) A safety brake device 38d with brake equipment 300a is illustrated in FIG. 7, which is characterized in that the brake elements 42a and 43a are each arranged at an angle W.sub.1 and W.sub.2 of incidence relative to a guide rail 7e. The angles W.sub.1 and W.sub.2 of incidence are possibly identical. When a braking or fixing process in downward direction is initiated smaller vibrations are as a result generated. The safety brake device 38d otherwise corresponds with the safety brake device 38c of FIG. 3 and the setting situation, which is illustrated there, of a cam disc 55a and an activating mechanism 400a with an activating lever 47a and an electromagnet 45a. The safety brake device 38d comprises a brake caliper 41a which is adjustably mounted in a support frame 40a of a load receiving means 2b. The safety brake device 38d is a component of an elevator installation 100b or a speed limiting system 200b.

(35) FIG. 8 schematically shows brake equipment 300e with a modified form of embodiment of a cam disc 55e for a safety brake device. In the case of this cam disc 55e the periphery of the cam disc is so designed that a peripheral section 65, which increases in radius, adjoins the flat 63e, the peripheral section 65 being followed by a straight, tangential peripheral section 85 constructed as a second brake element 43e. The brake element 43e can consist of the material of the cam disc or be a brake lining connected with the cam disc. In the case of activation of the safety brake device during travel of the load receiving means the peripheral section 65e, which increases in radius, of the cam disc 55e after rotation of the cam disc by the activating lever (not illustrated here) in counter-clockwise sense through an activation rotational angle comes into contact with the guide rail 7e moving upwardly relative to the cam disc. Through the friction between the periphery of the cam disc 55e and the guide rail 7e the cam disc is further rotated in counter-clockwise sense, wherein the rolling of the peripheral section 65e, which increases in radius, on the guide rail 7e produces a movement of the brake caliper 41e of the brake equipment 300e to the left, which has the consequence of a compression of the plate-spring packet 44e and a strong increase in the pressing forces between the cam disc 55e and the guide rail 7e as well as between the first brake element 42e and the guide rail 7e.

(36) FIG. 9 shows the brake equipment 300 according to FIG. 8 in the state in which after activation by the activating lever the cam disc 55e was rotated by the guide rail 7e to such an extent that the straight, tangential peripheral section 85e bears against the guide rail 7e and prevents further rotation of the cam disc. In this state, the brake equipment 300e slideswith the afore-mentioned pressing forces between the second brake element 43e of the cam disc 55e and the guide rail 7e as well as between the first brake element 42e and the guide rail 7erelative to the guide rail until the friction generated by the pressing forces has brought the load receiving means to a standstill.

(37) FIG. 10 shows a modified form of embodiment of a safety brake device, which has substantially the same features as the safety brake device described in FIGS. 2 to 6 and also fulfills the same purpose. However, some components of this modified form of embodiment are somewhat differently arranged and changed in part. The most significant difference relative to the afore-described safety brake device consists in that the activating mechanism 400k is not fixed to the support frame of the load receiving means, but is connected with the brake equipment or with the brake caliper. In order to be able to realize resetting, which results from a vertical relative movement between the support frame and the brake equipment, of the activating lever in the case of this arrangement as well, the lever abutment 75k is here connected with the support frame 40k instead of with the brake caliper.

(38) In this form of embodiment the activating lever 47k is so arranged that it activates the cam disc 55k when it moves in clockwise sense. This activating movement is no longer driven by an activating spring in the form of a torsion spring, but by a helical spring 52k acting from below on the left-hand arm of the activating lever 47k. The electromagnet, which restrains the activating lever in its initial position P.sub.I and which is not visible in FIG. 10, here acts from below on the left-hand arm of the activating lever, and also the coupling between the right-hand arm of the activating lever 47k and the cam disc 55k is designed somewhat differently. Also apparent is an additional pivot lever 90k. This has the effect that one end of the restraining spring 64k resiliently holding the cam disc 55k in its normal position is positioned in dependence on the position of the activating lever 47k. The purpose of this measure is to not allow the cam disc to rise too strongly against the restraining force, which urges it into its normal position, of the restraining spring during rotation of the cam disc. In that case, the switch 50k is possibly controlled by the position of the cam disc 55k so that on rotation of the cam disc out of the normal positionregardless of the position of the activating leverthe switch 50k is actuated and thus the drive of the elevator stopped. This construction of the switch 50k as well as the arrangement of the restraining spring 64k can also be used analogously in the case of the preceding embodiments.

(39) In at least some embodiments, remaining functions are substantially unchanged relative to the originally described form of embodiment of the safety brake device.

(40) Having illustrated and described the principles of the disclosed technologies, it will be apparent to those skilled in the art that the disclosed embodiments can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of the disclosed technologies can be applied, it should be recognized that the illustrated embodiments are only examples of the technologies and should not be taken as limiting the scope of the invention.