Method and Device for Controlling a Closing Movement of a Door of an Elevator Car in the Event of a Power Failure, Method for Retrofitting a Door of an Elevator Car, Door for an Elevator Car, and Elevator System

Abstract

A method for controlling a closing movement of a door of an elevator car in the event of a power failure uses the door drive and an electrical energy store. During normal operation of the door by the door drive, electrical energy is buffered in the energy store. In response to a power failure when the door is open, a closing mechanism begins to close the door and the stored electrical energy is provided as backup energy to the door drive by a control device to decelerate the closing movement.

Claims

1-13. (canceled)

14. A method for controlling a closing movement of a door of an elevator car in response to a power failure of a door drive acting on the door, the method comprising steps of: buffering electrical energy during a normal operation of the door by the door drive; in response to a power failure of the door drive, providing the buffered energy as backup energy to a door control device to operate the door drive and brake a closing movement of the door; and providing the backup energy intermittently to the door control device.

15. The method according to claim 14 including providing the backup energy with a delay of a predefined delay duration after the power failure occurs.

16. The method according to claim 14 including providing the backup energy when a start of the closing movement is detected.

17. The method according to claim 14 including interrupting the providing of the backup energy after a predefined provision duration.

18. The method according to claim 14 including interrupting the providing of the backup energy in response to detecting the braking of the closing movement.

19. The method according to claim 14 including interrupting the providing of the backup energy in response to detecting a start-up of the door control device.

20. The method according to claim 14 including interrupting the providing of the backup energy and resuming the providing after the interruption with a delay of a predefined delay duration.

21. The method according to claim 14 including providing the backup energy until the buffered energy is consumed.

22. A closing control device for controlling a closing movement of a door of an elevator car in response to a power failure of a door drive acting on the door, the closing control device being adapted to control the door drive using the method according to claim 14.

23. The closing control device according to claim 22 including connectors adapted to loop the closing control device into an energy line between an energy supply of the door control device and the door control device.

24. A method for retrofitting a door of an elevator car, the method comprising steps of: providing the closing control device according to claim 22; and looping the closing control device into an energy line between an energy supply of the door control device and the door control device.

25. A door for an elevator car, the door comprising: a mechanical closing mechanism that closes the door in response to a power failure of a door drive that opens and closes the door; the closing control device according to claim 22 looped into an energy line between an energy supply of the door control device and the door control device; and wherein the closing control device buffers electrical energy from the energy supply during the normal operation of the door by the door drive.

26. An elevator system comprising an elevator car having at least one door according to claim 25.

27. A closing control device for controlling a closing movement of a door of an elevator car in response to a power failure of a door drive acting on the door, the closing control device comprising: an energy store buffering electrical energy during a normal operation of the door by the door drive; control electronics that respond to a power failure of the door drive by providing the buffered energy from the energy store as backup energy to a door control device to operate the door drive and brake a closing movement of the door; and wherein the control electronics provide the backup energy intermittently to the door control device.

Description

DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a representation of an elevator system in accordance with an embodiment of the invention.

[0030] FIG. 2 is a front elevation view of the elevator car of the elevator system shown in FIG. 1.

[0031] The drawings are merely schematic and not to scale. The same reference signs indicate the same or equivalent features.

DETAILED DESCRIPTION

[0032] FIG. 1 is a representation of an elevator system 100 in accordance with an embodiment of the invention. The elevator system 100 has at least one elevator car 102. The elevator car 102 has a door 104 (FIG. 2). The door 104 is driven by a door drive 106. The door drive 106 acts on the door 104 via a cable or belt 107. The door 104 in this case has two opposing door leaves 108. The cable or belt moves the door leaves 108 in this case in opposite directions.

[0033] The door drive 106 is controlled via a control device 110. The control device 110 is supplied with a supply voltage 114 by an energy supply 112 or a power supply. The energy supply 112 converts alternating current from a power grid into direct current with a low voltage in order to generate the supply voltage 114. The supply voltage 114 is, for example, 24 volts.

[0034] The control device 110 energizes the door drive 106 using the supply voltage 114. As long as the door drive 106 is energized, it can move or hold the door 104. When the door drive 106 is without power, it can no longer exert any force on the door 104.

[0035] In the event of a power failure, the door 104 has a closing mechanism 116. The closing mechanism 116 is coupled to the door 104 and the door drive 106 via the cable or belt 117. The closing mechanism 116 has a mechanical energy store 118. In the energy store 118, mechanical energy is stored for closing the door 104 once in the event of a power failure. The energy store 118 is designed in this case as a spring, but can also be designed as a weight. The energy store 118 is charged or tensioned by the door drive 106 with each opening movement of the door 104 and is discharged or relaxed with each closing movement, and thereby supports the door drive 106. If the door 104 is open and the door drive 106 can no longer exert force on the door 104 due to the power failure, the mechanical energy stored in the energy store 118 pulls the door 104 closed with a closing movement.

[0036] In the approach presented here, a device 122 for controlling the closing movement of the door 104 in the event of a power failure is looped into an energy line 120 between the energy supply 112 and the control device 110. The device 122 has control electronics 124 and an electrical energy store 126. The energy store 126 can be designed, for example, as an accumulator and/or capacitor.

[0037] In the energy store 126, electrical energy is buffered during normal operation of the elevator system 100. During normal operation, the energy store 126 is therefore charged with the supply voltage 114 by the control electronics 124. During a power failure, the control electronics 124 provides the stored energy as backup energy 128 for the control device 110.

[0038] In one embodiment, the backup energy 128 is provided in pulses during the power failure, for example with current pulses periodically transmitted to the control device 110. While the backup energy 128 is provided, the control device 110 energizes the door drive 106, and the door drive 106 counteracts the closing movement driven by the closing mechanism 116. The closing movement is thereby braked or stopped. If the backup energy 128 is interrupted, the door drive 106 is no longer powered by the control device 110. As a result, the door drive 106 can no longer counteract the force of the closing mechanism 116, and the closing movement is again driven by the closing mechanism 116. Subsequently, backup energy 128 is provided again, and the closing movement is braked again. By a repeated sequence of providing the backup energy 128 and switching off the backup energy 128, the closing movement can be jerky or in pulses. The average speed of the closing movement can thus be significantly reduced.

[0039] In one embodiment, the backup energy 128 is not provided immediately after the power failure. Upon first providing backup energy, a predefined waiting time or delay duration 130 is waited. During the delay duration 130, the closing movement can begin. After the delay duration 130, the backup energy 128 is provided, and the control device 110 can power the door drive 106, whereby the closing movement is braked again.

[0040] In one embodiment, the provision of the backup energy 128 is interrupted after a predefined provision duration 132. During the provision duration 132, the backup energy 128 is provided. The provision duration 132 is long enough for the door drive 106 to brake the closing movement.

[0041] In one embodiment, the provision duration 132 depends on an initialization period of the control device 110. The control device 110 requires a moment after receiving the backup energy 128 until the door drive 106 is energized. The provision duration 132 can be longer than the initialization period so that the braking effect of the door drive 106 can develop.

[0042] In one embodiment, the delay duration 130 and the provision duration 132 are dependent on a size or mass of the door 104 and a strength of the closing mechanism 116. The provision duration 132 is also dependent on a braking performance of the door drive 106. The delay duration 130 and the provision duration 132 can be different for different elevator systems 100. If the device 122 is retrofitted, the delay duration 130 and the provision duration 132 can be parameterized during the retrofit.

[0043] In one embodiment, after the interruption of the provision, the delay duration 130 is again waited until the backup energy 128 is provided again. This alternation between providing and not providing can continue until the energy buffered in the electrical energy store 126 is used up. This can be done independently of the position of the door 104.

[0044] The provision and interruption can also be controlled. In particular, movement of the door can be detected and evaluated by sensors. The backup energy 128 can be provided, for example, when the start of the closing movement is detected. The provision can be interrupted if the braking of the closing movement is detected.

[0045] The provision can also be interrupted if the initialization or start-up of the control device 110 is signaled.

[0046] In one embodiment, the device 122 has connectors 134 via which the device 122 is looped into the energy line 120. The device 122 is independent of the door 104 and only monitors the supply voltage 114. After the supply voltage 114 stops, the buffered energy is provided as the backup energy 128. Due to the connectors 134, the device 122 can be particularly easily retrofitted to existing elevator systems 100.

[0047] In the following, possible embodiments of the invention are summarized again or presented using slightly different wording.

[0048] A device for installation in an elevator door, an elevator door, an elevator, a method for retrofitting an elevator and a method for slowly closing a door in the event of a power failure are presented.

[0049] Elevator doors have a mechanism that serves to close the door without the effect of additional force. These are usually springs or tensioning weights. If a power failure occurs when the door is open, a door drive no longer provides the force to keep the door open, and the door closes very quickly. This causes a loud bang and can damage the door.

[0050] The approach presented here causes the door to close slowly if a power failure occurs while the door is open. For this purpose, a device is looped into the power supply of the door drive.

[0051] If the power supply is intact, this simply passes the 24 V DC on to the door drive and simultaneously charges a capacitor or a battery.

[0052] In the event of a power failure, the door drive is alternately supplied with 24 V for a short time and then disconnected from the 24 V again.

[0053] The slow closing is achieved by the door drive booting as soon as it is supplied with power and then short-circuiting the coils of the motor. This blocks the drive. When the power supply drops again, the motor is released again. The door can always close a little bit and then stop again. As a result, it closes with less energy at the end. The device can continue to operate undisturbed even after it has been closed.

[0054] The device can be easily retrofitted since no part of the elevator needs to be adapted to this device. In regions that often have power failure, the device can be installed from the start without having to adapt the other components to the presence of the device.

[0055] 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 one do not preclude a plurality. Furthermore, it should be noted that features or steps which have been described with reference to one of the above exemplary embodiments may also be used in combination with other features or steps of other exemplary embodiments described above.

[0056] 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.