Safety monitoring device with instantaneous speed determination for a lift car

• US 7,438,158 B2
• Filed: 01/27/2005
• Issued: 10/21/2008
• Est. Priority Date: 02/20/2004
• Status: Active Grant

• Current Assignee: K.A. Schmersal Holding KG
• Original Assignee: K.A. Schmersal Holding KG
• Inventors: Heinzer, Volker, Hennemann, Olav
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US11/045,939
• Publication Number:
  US 20050230191A1
• Time in Patent Office: 1,363 Days
• Field of Search: 187391-394, 187286-288, 187/293, 187295-297, 187/305, 187/313, 187/247, 187/248
• US Class Current: 187/248
• CPC Class Codes: B66B 5/06 electrical

Abstract

A safety monitoring device is provided for a lift car which can be moved in a lift shaft by a traction drive via a lift control system and whose instantaneous position can be registered by a position registering device which supplies two position signals, produced independently of each other, in a predetermined time pattern, having two-channel evaluation of the position signals by means of a microprocessor in each case for location-dependent, instantaneous determination of the speed of the lift car and for comparison with a predefined movement profile, it being possible for a trigger signal that can be output via a safety relay stage to be generated if a predetermined instantaneous speed desired value is exceeded.

Claims

1. A safety monitoring device for a lift car which is moveable in a lift shaft by means of a traction drive via a lift control system and

whose instantaneous position is registratable by means of a position registering device which supplies two position signals, produced independently of each other, in a predetermined time pattern, having two-channel evaluation of the position signals by means of a microprocessor in each case for location-dependent, instantaneous determination of the speed of the lift car obtained from the two-channel evaluation of the position signals and for comparison with a predefined movement profile, wherein the two microprocessors communicate with each other via a line for mutual monitoring, in the case a predetermined instantaneous speed desired value is exceeded it being provided to generate a trigger signal outputed via a safety relay stage.

2. The device according to claim 1, wherein the instantaneous acceleration and/or a derivative of the acceleration of the movement of the lift car is determined by the microprocessors and compared with the predefined movement profile, it being possible for a trigger signal to be generated if a predetermined desired value is exceeded.

3. The device according to claim 1, wherein the microprocessors is synchronized by means of crosswise data comparison.

4. The device according to claim 1, wherein retardation monitoring with triggering of the action of stopping the traction drive and braking the lift car can be performed.

5. The device according to claim 1, wherein limiting the speed of the lift car with triggering of the action of stopping the traction drive and braking the lift car performable.

6. The device according to claim 1, wherein moving the lift car into a stopping position and/or readjusting the stopping position of the lift car and/or ramp travel control is performable, in each case with the doors open and while bridging the door switches.

7. The device according to claim 1, wherein a virtual protective space of predefined length can be generated temporarily in at least one end region of the lift shaft.

8. The device according to claim 1, wherein the function of emergency limit switches can be carried out.