SAFETY SWITCH ACTUATION DEVICE

Abstract

A safety switch actuation device for keeping the pushbutton switch activated and deactivated remotely, the actuation device comprising a plunger which can be brought by external probing from a standby position, in which it does not switch the pushbutton switch, to an active position, in which it keeps said pushbutton switch actuated, characterized in that the actuation device has a remotely controllable linear drive, a return spring and a return actuator and is designed in such a way that the plunger can be coupled to the return actuator by the remotely controllable linear drive, which is preferably driven by a Bowden cable, under tension of the return spring, which, after deactivation of the linear drive, is pressed by the return spring into a position more remote from the pushbutton switch, thereby entraining the plunger into its standby position.

Claims

1. A safety switch actuation device for keeping a pushbutton switch activated and deactivated remotely, the actuation device comprising: a plunger which can be brought by external probing from a standby position, in which the plunger does not switch the pushbutton switch, to an active position, in which the plunger keeps said pushbutton switch actuated; a remotely controllable linear drive; a return spring; and a return actuator, wherein the actuation device is designed in such a way that the plunger can be coupled to the return actuator by the remotely controllable linear drive, which is driven by a Bowden cable, under tension of the return spring, which, after deactivation of the linear drive, is pressed by the return spring into a position more remote from the pushbutton switch, thereby entraining the plunger into the standby position.

2. The actuation device according to claim 1, wherein the return actuator is designed to hold the plunger in the standby position after retrieval until a next activation.

3. The actuation device according to claim 1, wherein the actuation device comprises an activation spring which keeps the plunger in the active position after tripping, and the activation spring is compressed back to a position the activation spring occupies in the standby position in the course of a recoupling movement imposed by the linear drive on the return actuator.

4. The actuation device according to claim 1, wherein the plunger is designed, mounted and coupled in the standby position to the return actuator in such a way that the coupling is cancelled by a force triggering the plunger as intended or the coupling is weakened to such an extent that the plunger is transferred to the active position by an activation spring tensioning the plunger and is held there as long as no further external force is applied.

5. The actuation device according to claim 1, wherein the plunger carries a first part of a magnetic coupling and the return actuator carries or forms a second part of a magnetic coupling, and the linear drive is designed in such a way that the linear drive can bring the return actuator under tension of the return spring so close to a plunger-side part of the magnetic coupling that a return-actuator-side part of the magnetic coupling engages the plunger-side part of the magnetic coupling.

6. The actuation device according to claim 3, wherein the activation spring and the return spring are matched to one another in such a way that a force required to compress the return spring is greater, at least towards an end of the recoupling movement of the return actuator, than a force required to compress the activation spring, the forces differing towards the end of the recoupling movement by a maximum of 17%.

7. The actuation device according to claim 5, wherein a holding force of the magnetic coupling, which is closed without an air gap, is greater than the force of an activation spring, which presses the plunger into the active position after the plunger has been triggered.

8. The actuation device according to claim 5, wherein an activation spring receives the magnetic coupling therein.

9. The actuation device according to claim 1, wherein the plunger has a free end which protrudes from the actuation device housing and which in turn forms a pushbutton by the pushbutton actuation of which the actuation device can be activated.

10. The actuation device according to claim 5, wherein the actuation device has a bearing sleeve which is mounted displaceably with an outside of the bearing sleeve in a housing of the actuation device and forms in its interior the second part of the magnetic coupling which in turn has a bearing bore in which the plunger is mounted displaceably, wherein the plunger in turn carries the first part of the magnetic coupling and the plunger engages through an activation spring, wherein the activation spring is supported in such a way that its spring bias tends to push the first and the second part of the magnetic coupling apart, and the return spring is supported against an end face of the bearing sleeve.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0036] FIG. 1 shows the actuation device unit with pushbutton switch in the assembled state.

[0037] FIG. 2 shows the actuation device together with the pushbutton switch in sectional view in the ready position.

[0038] FIG. 3 shows the actuation device together with the pushbutton switch in sectional view during operation of the pushbutton switch.

[0039] FIG. 4 shows the actuation device together with the pushbutton switch in sectional view during actuation of the Bowden cable.

[0040] FIG. 5 shows the actuation device together with the pushbutton switch in sectional view after actuation of the Bowden cable.

[0041] FIG. 6 shows the actuation device with the pushbutton switch in the mounted state in isometric view.

[0042] FIG. 7 shows the actuation device with the pushbutton switch without environment.

[0043] FIG. 8 shows the actuation device with the pushbutton switch in isometric view.

[0044] FIG. 9 shows a second variant of the actuation device with pushbutton switch in isometric view.

[0045] FIG. 10 shows the second variant of the actuation device with pushbutton switch in the mounted state in the isometric view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] The operation of the invention is described by way of example with reference to FIGS. 1 to 8.

[0047] FIG. 1 shows how the actuation device 1 is mounted together with the pushbutton switch 2 on a mounting plate 27 in the area of the overspeed governor sheave 28 and the associated “emergency brake” 23. In this case, the actuation device 1 is still in the inactive state, i.e. the safety conductor 22, which cannot be seen in FIG. 1, is not yet in contact with the plunger 3 of the actuation device 1. Also, the plunger 3 of the actuation device 1 has not yet been actuated by the emergency brake 23. The connection of the housing 21 of the actuation device 1 to the pushbutton switch 2 can be seen in FIGS. 2 to 5.

[0048] The housing 21 ideally has a suitable recess on its side facing away from the emergency brake 23, with which it receives the collar of the pushbutton switch.

[0049] With reference to FIGS. 2 and 3, which show a section of FIG. 1 in sectional view, it can be explained that the initially not yet actuated plunger 3 is actuated by the emergency brake 23 and is finally brought into contact with the pushbutton switch 2 or the safety conductor 22 of the pushbutton switch 2 by the activation spring 17.

[0050] In Fig. the plunger 3 is still in the unactuated state, i.e. the actuation device 1 is in the standby position. Thus, the end of the plunger 3 facing away from the emergency brake 23 and the safety conductor 22 of the pushbutton switch 2 are not yet in contact. The magnetic coupling 18, which is located in the bearing sleeve 13 of the return actuator 12, or the second part 20 of which is also a component of the return actuator 12, is in its closed state. That is, the first part 19 of the magnetic coupling 18, which is ideally formed by a permanent magnet and which is mounted on the plunger 3, and the second part 20 of the magnetic coupling 18 are in contact with each other. In this case, the magnetic holding force of the magnetic coupling 18 is greater than the spring force of the activation spring 17, which exerts a force on the first part 19 of the magnetic coupling 18 acting in a direction away from the second part 20 of the magnetic coupling 18. Since the first part 19 of the magnetic coupling 18 and the plunger 3 are positively connected to each other in the axial direction of the plunger 3, the spring force of the activation spring 17 also acts on the plunger 3. However, there is no movement of the plunger 3 due to the closed magnetic coupling 18.

[0051] In this case, the first part 19 of the magnetic coupling 18 is ideally cylindrical, as in the embodiment example shown, and has a through-hole in the center with which it is pushed onto the plunger 3. In order to prevent the first part 19 of the magnetic coupling 18 from slipping on the plunger 3, one end face of the first part 19 of the magnetic coupling 18 preferably rests against a shoulder 15 of the plunger 3 and the other end face of the first part 19 preferably rests against a washer 25, which in turn is secured against displacement along the plunger 3 by a circlip 24.

[0052] The second part 20 of the magnetic coupling 18 is ideally formed by a soft magnetic material. It is located in the bearing sleeve 13 and together with it forms the retainer 12. It is also conceivable that the bearing sleeve 13 and the second part 20 of the magnetic coupling 18 are manufactured in one piece. The second part 20 of the magnetic coupling 18 has a through hole in the center through which the plunger 3 projects. There is sufficient clearance between the through bore of the second part 20 of the magnetic coupling 18 and the plunger 3, so that the plunger 3 can be displaced relative to the second part 20 of the magnetic coupling 18. In addition, the second part 20 of the magnetic coupling 18 has a shoulder on which the activation spring 17 is supported. On the opposite side, the activation spring 17 is supported on the washer 25. With their end face facing away from the pushbutton switch 2, the bearing sleeve 13 and the second part 20 of the magnetic coupling 18 rest against the housing 21 of the actuation device 1 in the standby position of the actuation device 1.

[0053] The plunger 3, which is mounted axially displaceably in the return actuator 12, protrudes from the actuation device unit 1 with its end facing the emergency brake 23. The end facing the emergency brake 23 forms the button 16 via which the emergency brake 23 activates the plunger 3.

[0054] In the event of emergency braking, the emergency brake 23 moves in the direction of the plunger 3 until it comes into contact with the pushbutton 16 of the plunger 3 and exerts a force on the plunger 3 in the direction of the pushbutton 2. This actuating force causes the plunger 3, together with the first part 19 of the magnetic coupling 18 positively connected to it, to move in the direction of the pushbutton switch 2 against the holding force of the magnetic coupling 18. However, the plunger 3 is then not yet in contact with the safety conductor 22 of the pushbutton switch. Only an air gap is formed between the first part 19 and the second part 20 of the magnetic coupling 18. This air gap results in a reduction of the magnetic force, so that the spring force of the activation spring 17 exceeds the magnetic force. This results in a relaxation of the activation spring 17, which moves the washer 25 together with the plunger 3 and the first part 19 of the magnetic coupling 18 in the direction of the pushbutton switch 2.

[0055] In the process, the plunger 3 comes into contact with the safety conductor 22 of the pushbutton switch 2 and actuates it, so that the safety circuit of the elevator is interrupted. This condition is shown in FIG. 3.

[0056] FIGS. 4 and 5 show how the activated pushbutton switch is released again with the aid of the linear drive provided for this purpose by bringing the actuation device 1 back into the standby position. In this embodiment example, the linear drive is preferably formed by the pin 4 guided in the guide 5 and the Bowden cable 7, 8, 9, 10 actuating it, which can be subjected to force from a distance by an actuating member not shown here, which is operated by the service technician, often by hand.

[0057] First, the Bowden cable 6 is actuated, which is supported on the housing 21 of the actuation device 1 via the nuts 9 screwed onto the wire rope guide 8. This moves the connecting sleeve 10, which is connected to the wire rope 7, in the direction of the pushbutton switch 2. At its end facing away from the pushbutton switch 2, the connecting sleeve 10 has a bore through which the pin (4) forming the linear drive 4 projects. The movement of the connecting sleeve 10 in the direction of the pushbutton switch 2 therefore also results in a movement of the pin 4 in the same direction. The pin 4 is thereby guided by a bolt guide 5 designed as a groove in the housing 21 of the actuation device 1. With its end facing the plunger 3, the pin 4 projects into a bore provided for this purpose in the return actuator 12. Since the return actuator 12 is formed by the bearing sleeve 13 and the second part 20 of the magnetic coupling 18, the pin 4 consequently projects into corresponding bores in the bearing sleeve 12 and the second part 20 of the magnetic coupling. Thus, there is a positive fit between the pin 4 and the return actuator 12 in the axial direction of the plunger 3.

[0058] Consequently, the movement of the pin 4 in the direction of the pushbutton switch 2 as a result of the actuation of the Bowden cable 6 also causes a movement of the return spring 12 in the direction of the pushbutton switch 2. In the process, the return spring 11, which is supported with its one end in a mostly centering manner on the housing 21 of the actuation device 1 and with its other end on the end face of the bearing sleeve 13 facing the pushbutton switch 2, is compressed.

[0059] At the same time, the activation spring 17 is compressed until the second part 20 of the magnetic coupling 18 and the first part 19 of the magnetic coupling 18 are in contact again. The magnetic force of the magnetic coupling 18 is then again greater than the spring force of the activation spring 17. The position of the plunger 3 does not change until then. The plunger 3 therefore continues to press against the safety conductor 22 of the pushbutton switch 2.

[0060] If the linear drive is now deactivated by releasing the Bowden cable 6, the return spring 11 relaxes and thereby moves the return actuator 12 in the direction away from the pushbutton switch 2 until the return actuator 12 rests against the housing 21 of the actuation device. Since the magnetic coupling 18 is closed during this time, the first part 19 of the magnetic coupling 18 and the plunger 3 connected to it are also moved in the direction away from the pushbutton switch 2 as a result. The plunger 3 then no longer presses against the safety conductor 22 of the pushbutton switch 2 and the safety circuit is closed again.

[0061] The spring force of the return spring 11 is less than the sum of the forces exerted on the plunger 3 by the emergency brake 23 and the activation spring 17 in the event of emergency braking. As a result, if the Bowden cable 6 becomes jammed and its release requires a force greater than that required to activate the pushbutton switch 2, the return actuator 12 will not be forced away from the pushbutton switch 2 by the return spring 11. Accordingly, the plunger 3 remains in contact with the safety conductor 22 until the Bowden cable 6 actually no longer exerts a force on the pin 4 in the direction of the pushbutton switch 2.

[0062] In FIG. 6, the actuation device 1 mounted on the mounting plate 27 is shown in isometric view together with the pushbutton switch 2 and the overspeed governor sheave 28.

[0063] It can also be seen from FIGS. 7 and 8 that a groove 26 is provided in the housing 21 of the actuation device 1, which serves as a guide for the plunger 3.

[0064] FIG. 9 and FIG. 10 show a second variant of the actuation device 1 and the pushbutton switch 2 in the unassembled (FIG. 9) and assembled state (FIG. 10).

[0065] While the pushbutton switch is designed analogously to the previous variant, the further connection of the Bowden cable 6 changes. The Bowden cable 6 is no longer directly connected to the guided pin. Preferably, the following embodiment is selected: First, the Bowden cable 6 is again provided with a connecting sleeve 10. However, this does not directly enclose the guided pin, but an axle 30, the connecting axle, which has no direct contact with the mechanics of the actuation device. Instead, this axle is connected to a U-frame 29, which is rotatably mounted on the housing of the actuation device 21 with a second axle, the rotation axle 31. The rotary movement of the U-frame 29 triggered by the Bowden cable 6 switches the actuation device in the same way as in the first variant, except that here the U-frame performs the switching operation. In order to be able to rotate the U-frame, the housing of the actuation device 21 must also be designed differently than in the first variant. At its end, therefore, are two cylindrical elevations with through holes. The housing 21 has two such through-holes to allow the U-frame to be mounted from above or below, depending on which side is more convenient for installing the Bowden cable.

[0066] This variant thus provides a more robust and safe way of performing the switching operation. In addition, the actuating force can be adjusted via the constructive lever arm (distance between the rotation axle and the connecting axle).