Safety brake for a lifting device

Patent metadata

Field	Value
Publication number	US-10112813-B2
Application number	US-201615542965-A
Country	US
Kind code	B2
Filing date	Jan 15, 2016
Priority date	Jan 15, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A method and a safety brake for a lifting device, wherein a solenoid or another electromechanical actuator is used to actuate a pawl, where the position of the pawl is monitored via at least two switches or sensors, where the lowering motion of the load or the lifting device is monitored and the safety brake is triggered in the event of a fault via a safety-oriented controller and at least one sensor, where the solenoid or the pawl is arranged such that, via spring force and/or gravity, the pawl is brought into engagement when the actuator, for example, the solenoid, is deenergized such that it is possible to exactly define and monitor the limit speed and, by using the two sensors, it is also possible to monitor the function and the motion of the pawl and to detect undesired operating states.

First claim

The invention claimed is:

1. A safety brake for a lifting device, comprising:
a brake blocking gear element connected to at least one drive of the lifting device;
a pawl for engaging in a latch void of the brake blocking gear element in cases of an impermissible lowering speed of the lifting device, the brake blocking gear element being blocked;
an actuator for activating the pawl, the pawl and the actuator being configured and arranged such that, in a non-energized state of the actuator, the pawl bears on the brake blocking gear element or moves into the latch void of the brake blocking gear element, and in an energized state of the actuator, the pawl moves away from the brake blocking gear element or moves out of the latch void and releases the brake blocking gear element;
an electronic or numeric controller for controlling the at least one drive and for activating the actuator, the controller monitoring the lowering speed of the lifting device, a transfer of the actuator to the non-energized state occurring when the permissible lowering speed is exceeded; and
at least two sensors which are linked to the controller for determining an operating state of the pawl, a differentiation with respect to the operating state being determinable at least between the moved-away state, the bearing state, and the completely moved-into the latch void state via the at least two sensors.

2. The safety brake as claimed in patent claim 1 , wherein the actuator is an electric lifting magnet.

3. The safety brake as claimed in patent claim 1 , wherein the latch void of the brake blocking gear element is configured such that the pawl in cases of the lifting device being lowered moves completely into the latch void only when the pawl bears on the brake blocking gear element.

4. The safety brake as claimed in patent claim 1 , wherein the controller activates the drive of the lifting device; wherein the controller is configured such that lowering of the lifting device in a regular operation is performed only in the energized state of the actuator.

5. The safety brake as claimed in patent claim 4 , wherein the controller is further configured such that bringing the pawl to bear on the brake blocking gear element in the regular operation is performed only in cases of a stationary drive of the lifting device.

6. The safety brake as claimed in patent claim 1 , wherein one of (i) a rope encoder is connected to the lifting device for monitoring a lowering speed of the lifting device and (ii) a rotational speed sensor is connected to the drive of the lifting device for monitoring the lowering speed of the lifting device.

7. The safety brake as claimed in patent claim 6 , wherein one of (i) the rope encoder and (ii) the rotational speed sensor is configured in a fail-safe or redundant manner.

8. The safety brake as claimed in patent claim 1 , wherein the controller is configured in a fail-safe or redundant manner.

9. The safety brake as claimed in patent claim 1 , wherein a test run for testing the at least two sensors is implemented, the lifting device being lowered in cases of a non-energized actuator, the actuator being switched to a non-energized state, and the signals of the sensors being verified when the pawl is being brought to bear and is moving in.

10. The safety brake as claimed in patent claim 1 , wherein at least one sensor of the at least two sensors is formed as a switch.

11. A method for a safety brake for a lifting device, a brake blocking gear element being directly or indirectly connected to a drive of the lifting device, a pawl engaging in a latch void of the brake blocking gear element in cases of an impermissible lowering speed of the lifting device occurring, and the brake blocking gear element being blocked, the method comprising:
activating the pawl via an actuator;
pressing the pawl against the brake blocking gear element or moving the pawl into the latch void of the brake blocking gear element in a non-energized state of the actuator; and
moving the pawl away from the brake blocking gear element or moving the pawl out of the latch void in an energized state of the actuator, said brake blocking gear element being released;
wherein activation of the actuator is performed by an electronic or numeric controller, a lowering speed of the lifting device being monitored by the controller and the actuator being set to the non-energized state when a permissible lowering speed is exceeded;
wherein a respective operating state of the pawl is detected by at least two sensors, a differentiation with respect to the operating state occurring at least between the moved-away state, a bearing state and the completely moved-into the latch void state via the at least two sensors; and
wherein signals of the at least two sensors and the detected speed are used by the controller to actuate the actuator and the drive.

12. The method as claimed in patent claim 11 , wherein a lowering motion of the drive in a regular operation is switched off by the controller when at least one of (i) any exceeding of the permissible lowering speed is established and (ii) the bearing state or the completely moved-into the latch void state of the pawl is detected.

13. The method as claimed in patent claim 12 , wherein a test run is performed to test the at least two sensors, the drive of the lifting device in cases of a non-energized actuator being switched to the lowering operation by the controller, the actuator being switched to the non-energized state, and functioning of the at least two sensors being verified when the pawl is being brought to bear and is moving in.

14. The method as claimed in patent claim 11 , wherein a test run is performed to test the at least two sensors, the drive of the lifting device in cases of a non-energized actuator being switched to the lowering operation by the controller, the actuator being switched to the non-energized state, and functioning of the at least two sensors being verified when the pawl is being brought to bear and is moving in.

Assignees

• Siemens Ag

Inventors

• HEIL Reudiger
• Staub Eugen
• Hoermann Walfried

Classifications

• B66D5/30

  electrical · CPC title

• F16D2127/002

  speed-responsive · CPC title

• F16D41/12

  with hinged pawl co-operating with teeth, cogs, or the like (F16D41/02, F16D41/24 take precedence) · CPC title

• F16D65/16

  arranged in or on the brake · CPC title

• B66D2700/05

  Brakes with mechanisms with latches for hoists or similar devices · CPC title