SAFETY SWITCHING SYSTEM AND METHOD FOR SWITCHING AN ELEVATOR INSTALLATION BETWEEN A NORMAL OPERATING MODE AND AN INSPECTION OPERATING MODE

Abstract

An elevator system inspection control system and method for switching between normal and inspection operating modes includes a safety chain series circuit having at least one shaft or door contact switch and an operating device in an elevator shaft. The operating device includes a changeover switch for switching between modes. The safety chain is closed to drive an elevator car by establishing a current path between an electrical power source and a motor. When interrupted, the safety chain interrupts the current path thereby stopping the car. The control system includes a manual switch outside the shaft and a control element. The safety chain is closed or interrupted by activating or deactivating the control element while the current path to the motor remains permanently interrupted until the manual switch is actuated when the changeover switch switches the elevator system from the inspection operating mode to the normal operating mode.

Claims

1-13. (canceled)

14. An inspection control system of an elevator system, the elevator system including an elevator car and an electric motor, wherein the motor drives the elevator car to move in a shaft of the elevator system and wherein the shaft has at least one shaft door, and a safety chain that includes at least one door contact switch for determining an open and/or closed state of the at least one shaft door connected in a series circuit with an operating device in the shaft, wherein the operating device includes a changeover switch for switching the elevator system between a normal operating mode and an inspection operating mode, and wherein the safety chain when closed establishes a current path between an electrical supply source and the motor for driving the elevator car and the safety chain when interrupted interrupts the current path for stopping the elevator car, the inspection control system comprising: a manual switch and at least one control element for controlling the safety chain, the manual switch being located outside the shaft; and wherein the series circuit of the safety chain is closed by activating the at least one control element and is interrupted by deactivating the at least one control element, and wherein while safety chain and thus the current path to the motor remains interrupted until the manual switch is actuated when the changeover switch of the operating device switches the elevator system from the inspection operating mode to the normal operating mode.

15. The inspection control system according to claim 14 wherein actuation of the manual switch activates the at least one control element.

16. The inspection control system according to claim 14 wherein switching the elevator system into the inspection operating mode by the changeover switch deactivates the at least one control element.

17. The inspection control system according to claim 14 wherein the at least one control element is a control relay that includes a control unit and at least one switch.

18. The inspection control system according to claim 17 wherein the at least one switch is an operating switch connected in the series circuit of the safety chain and the control relay controls the operating switch to alternately establish and interrupt the current path to the electric motor.

19. The inspection control system according to claim 14 wherein the at least one control element is an electronic circuit for controlling the safety chain and the current path.

20. The inspection control system according to claim 14 wherein the electronic circuit is a programmable electronic system in safety-related applications.

21. The inspection control system according to claim 14 wherein the operating device includes a control switch that controls the motor for driving the elevator car in the inspection operating mode only.

22. The inspection control system according to claim 14 wherein the safety chain includes a further switch for switching the safety chain to deactivate the operating device for preventing or interrupting movement of the elevator car.

23. The inspection control system according to claim 14 wherein the operating device is located in a shaft pit of the shaft.

24. An elevator system comprising: elevator car movable in an elevator shaft, wherein the shaft has at least one shaft door; an electric motor driving the elevator car to move in the shaft; a safety chain that includes at least one door contact switch for determining an open and/or closed state of the at least one shaft door connected in a series circuit with an operating device in the shaft, wherein the operating device includes a changeover switch for switching the elevator system between a normal operating mode and an inspection operating mode, and wherein the safety chain when closed establishes a current path between an electrical supply source and the motor for driving the elevator car and the safety chain when interrupted interrupts the current path for stopping the elevator car; and an inspection control system according to claim 14 for controlling the safety chain.

25. A method for switching an elevator system between a normal operating mode and an inspection operating mode, the elevator system including an elevator car and an electric motor driving the elevator car to move in a shaft of the elevator system, and wherein the shaft has at least one shaft door, the method comprising the steps of: providing a safety chain having at least one door contact switch and an operating device connected in a series circuit, the operating device being in the shaft, wherein an opening and/or closing state of the at least one shaft door is determined by the at least one door contact switch; switching the elevator system between the normal operating mode and the inspection operating mode with a changeover switch of the operating device; establishing a current path between an electrical supply source and the electric motor through the safety chain when closed for driving the elevator car and interrupting the current path by interrupting the safety chain to stop the elevator car from moving; and controlling the safety chain and the current path by actuating a manual switch arranged outside the shaft to activate at least one control element to close the series circuit of the safety chain and to deactivate the at least one control element to interrupt the series circuit of the safety chain, and keeping the current path to the motor interrupted until the manual switch is actuated when a changeover switch of the operating device switches the elevator system from the inspection operating mode to the normal operating mode.

26. The method according to claim 25 including deactivating the at least one control element by switching the elevator system into the inspection operating mode using the changeover switch.

27. The method according to claim 25 including during the inspection operating mode of the elevator system, controlling the motor only with a control switch of the operating device in order to drive the elevator car.

28. An elevator system switched between a normal operating mode and an inspection operating mode using the method according to claim 25, the elevator system comprising: elevator car movable in an elevator shaft, wherein the shaft has at least one shaft door; an electric motor driving the elevator car to move in the shaft; a safety chain that includes at least one door contact switch for determining an open and/or closed state of the at least one shaft door connected in a series circuit with an operating device in the shaft, wherein the operating device includes a changeover switch for switching the elevator system between a normal operating mode and an inspection operating mode, and wherein the safety chain when closed establishes a current path between an electrical supply source and the motor for driving the elevator car and the safety chain when interrupted interrupts the current path for stopping the elevator car; and an inspection control system for controlling the safety chain.

Description

DESCRIPTION OF THE DRAWINGS

[0021] An advantageous embodiment of the invention will be described below with reference to the enclosed drawings, wherein neither the drawings nor the description is to be interpreted as limiting the invention. The drawings are only schematic and are not true to scale.

[0022] In which:

[0023] FIG. 1 is a schematic representation of an elevator system,

[0024] FIG. 2 shows the schematic structure of a conventional safety chain in an elevator system,

[0025] FIG. 3 (collectively FIGS. 3.1 through 3.6) shows the schematic structure of the safety chain of an inspection control system according to the invention,

DETAILED DESCRIPTION

[0026] FIG. 1 illustrates an elevator system 1, with a simplified schematic representation of a safety chain 14 being shown accordingly. The safety chain 14 is used to monitor a state of a plurality of safety-related parameters of the elevator system 1. An electric motor 12 drives an elevator car 8 in an elevator shaft 5 between different floors for transporting people. A shaft door 11 is provided on each floor and a car door (not shown) is provided on the elevator car 8. The shaft door 11 can be opened or closed alone or together with the car door. At least one door contact switch 15 is provided on each of the shaft doors 11 and on the car door, with the aid of which it can be monitored whether the respective shaft or car door is currently closed or open. In particular, the door contact switches 15 are connected in series, so that a part of the safety chain thus formed is only closed as a whole when all the door contact switches 15 are closed. Even if only one door contact switch 15 is open, the elevator car 8 is considered unsafe and is shut down by the controller.

[0027] FIG. 2 shows a conventional safety chain 14, which is presented as a circuit based on the safety chain 14 in FIG. 1. This circuit is supplied with an electrical supply source—for example a power source 10a in this exemplary embodiment—and has one or more door contact switches 15, an operating device 3 and at least one further switch 6. By means of this further switch, the safety chain 14 can be closed or interrupted either manually or automatically. The further switch 6 is, for example, an emergency stop switch which is arranged in the shaft 5 (see FIG. 1). The operating device 3 has a changeover switch 4 for switching the elevator system 1 into a normal or inspection operating mode and a control switch (e.g., a direction switch) 16 for controlling an elevator car 8 for moving in an upward or downward direction. If necessary, other switches 6 can be further connected to the safety chain 14. It is important that all switches belonging to the safety chain are connected to one another in a series circuit. Only when the safety chain 14 is closed as a whole can a current path to the electric motor 12 and to the power supply of the elevator system 1 be established so that the elevator system 1 is set to the normal or inspection operating mode in order to be able to drive the elevator car 8 to move in the elevator shaft. The current state of the safety chain 14, which is shown in FIG. 2, is for an elevator system 1 set in normal operation.

[0028] FIG. 3 consists of FIG. 3.1 to FIG. 3.6, which show an inspection control system 2 according to the invention in different switching states. In addition to the conventional safety chain 14 according to FIG. 2, a control circuit is arranged which is supplied either separately from the current source 10a to the safety chain 14 or from another current source 10b. The control circuit includes a manual switch 7, which is located outside the shaft 5, and three control elements K1, K2 and K3. In this exemplary embodiment, the control elements are three control relays, each of which has a control unit S1, S2, S3 and one or more switches. With simple buttons, touch and other technologies, the manual switch 7 can be designed with a variety of design options, such as in the form of a reset button, a rotary switch, a pressure switch, a toggle switch or a combined group of switches. In this embodiment, the control relay K1 controls its three switches K1-1 to K1-3, the control relay K2 controls its two switches K2-1 and K2-2, and the control relay K3 controls its five switches K3-1 to K3-5. All switches of a control relay do not have to be in the same switching state but switch over at the same time. The switches K2-2 and K3-5 serve as an operating switch, which can be connected in series independently of one another to lock and release the electric motor 12. For better clarity, control units S1, S2, S3 are shown symbolized in FIG. 3 in each case by a rectangular block, an activated control unit being marked with a black block, while a deactivated control unit is marked with a white block. An inspection switch 4a is arranged between the power source 10b and the control unit S1, which is always switched over simultaneously with the changeover switch 4 and interacts with the switches K1-3 or K2-1 to allow or interrupt a current flow to the control unit S1. The inspection switch 4a and the changeover switch 4 can alternatively be designed as a switch and belong to the operating device 3.

[0029] FIG. 3.1 shows the inspection control system 2 according to the invention with a closed safety chain 14 when the elevator system 1 is in the normal operation mode. The safety chain 14 and the control circuit are fed separately from the current sources 10a and 10b. The changeover switch 4 of the operating device 3 is in a normal operating switch position. Since a current flows through the control unit S1, the switches K1-1 and K1-3 are closed, as a result of which the safety chain 14 is closed. The elevator system 1 can now be driven by the electric motor 12.

[0030] FIG. 3.2 shows the inspection control system 2, wherein the safety chain 14 can be closed or interrupted manually by means of the operating device 3 during inspection work. It is assumed that the operating device 3 is located in the shaft pit 5a (see FIG. 1) of the shaft 5 and the inspection work is to be carried out in a shaft pit 5a. After a technician (not shown) enters the shaft pit 5a, he has to switch the changeover switch 4 of the operating device 3 to switch to an inspection switch position. The control relay p is activated when switching over because a current flow from the current source 10b to the control unit S1 is interrupted. The switches K1-1 and K1-3 are opened as a result of the activation of the control relay K1, whereas the switch K1-2 is closed. The safety chain 14 is thus interrupted first. However, since the switch K1-2 remains closed, the safety chain 14 can be closed manually and interrupted again in that the technician manually closes or opens the control switch or the direction switch 16 of the operating device 3. The elevator system 1 or the elevator car 8 can thus be driven in an upward or downward direction by the electric motor 12.

[0031] FIG. 3.3 shows that the safety chain 14 initially remains interrupted when the technician switches the changeover switch 4 back to the normal operating switch position after the inspection work. At this moment the technician is still in shaft 5. Although the elevator system 1 has now been switched to normal operation, it should not be set to normal operation beforehand for safety reasons, because the safety chain 14 remains interrupted by the open switches K1-1, K3-3 and the non-actuated control switch 16 and, as a result, cannot move the elevator car 1 automatically in the meantime. The technician can then leave the shaft pit 5a and go to the outside of the shaft 5 via a shaft door 11. In this case, the technician is safely protected on a route between the shaft pit 5a and the shaft door 11.

[0032] FIG. 3.4 to FIG. 3.5 show how the inspection control system 2 switches when the technician leaves the shaft 5 and has manually operated the manual switch 7. Since the control unit S3 of the control relay K3 is fed from the power source 10b as a result of the switched-on manual switch 7, the switches K3-1 and K3-5 are opened. At the same time, however, the switches K3-2, K3-3 and K3-4 are closed, as a result of which the safety chain 14 is connected to the second current source 10b through the switch K3-2. As a result of the closed switches K3-3 and K3-4, it in turn forms a continuous current path via the safety chain 14 to the control unit S2 of the control relay K2 (FIG. 3.5). The activated control relay K2 then opens the switch K2-2. Since the switches K3-5 and K2-2 are opened, the electric motor 12 remains blocked in advance despite a closed safety chain 14.

[0033] FIG. 3.6 shows how the inspection control system 2 continues to be switched after the switching state shown in FIG. 3.5. Due to the activated control unit S2 of the control relay K2, the switch K2-1 is also switched on. The relay K1 is thus activated by a current supplied to the control unit S1. The relay K1 now closes the switches K1-1 and K1-3 or opens the switch K1-2. Since the two switches K3-5 and K2-2 remain open, the electric motor 12 is always separated from the closed safety chain 14.

[0034] The inspection control system 2 can then switch and set the elevator system 1 to normal operation again. Now the technician releases the manual switch 7 or the manual switch 7 releases itself with a reset function. Current then no longer flows through the control unit S3 and it is deactivated, whereby the switches K3-1, K3-5 are closed and K3-2, K3-3 and K3-4 are opened. The safety chain 14 is again supplied from the power source 10a via the closed switch K3-1. The switching state of the safety chain 14 or the inspection control system 2 corresponds to the switching state shown in FIG. 3.1. In other words, the inspection control system 2 has a closed safety chain 14, and the elevator system 1 is only reset to normal operation again from this moment onwards.

[0035] In summary, an elevator system 1 which has an inspection control system 2 according to the invention or is controlled by this system is ensured when switching from an inspection operation to normal operation, because the elevator car 8 is prevented from moving if it is not determined whether a technician has left the shaft 5 of the elevator system 1 after an inspection work. This is independent of whether the safety chain 14 is closed or interrupted. Before manual actuation is carried out, it can also be understood that the drive of the elevator car 8, for example the electric motor 12, is always disconnected from an electrical supply source 10a, 10b.

[0036] Finally, it should be noted that terms such as “having,” “comprising,” etc. do not preclude other elements or steps, and terms such as “a” or “an” do not preclude a plurality of elements or steps. Furthermore, it should be noted that features or steps that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above.

[0037] It is pointed out that possible features and advantages of embodiments of the invention are described here partly with reference to a method according to the invention and partly with reference to a device according to the invention. A person skilled in the art will recognize that the individual features can be combined, modified, or exchanged in a suitable manner and that features described in particular for the method can be transferred analogously to the device and vice versa in order to arrive at further embodiments of the invention.

[0038] 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.

LIST OF REFERENCE SIGNS

[0039] 1 elevator system

[0040] 2 inspection control system

[0041] 3 operating device

[0042] 4 changeover switch

[0043] 4a inspection switch

[0044] 5 shaft

[0045] 5a shaft pit

[0046] 6 another or further switch

[0047] 7 manual switch

[0048] 8 elevator car

[0049] 10a a first power source

[0050] 10b a second power source

[0051] 11 shaft door

[0052] 12 electric motor

[0053] 14 safety chain

[0054] 15 door contact switch

[0055] 16 control switch/direction switch

[0056] Kn-x a switch of the control relay (n=1 to 3, x=1 to 5)

[0057] S1-S3 control unit of the control relay