Actuator for an elevator brake

Abstract

An elevator installation braking device is actuated and reset by an electromechanical actuator including an energy store, a retaining device, a resetting device and at least one connecting element for connecting the actuator to the elevator brake. The resetting device retains the connecting element, via the retaining device and counter to the action of the energy store, in a first operating position, corresponding to a standby position of the brake, or guides the actuator back into this position. The energy store acts as required, upon release of the retaining device, on the connecting element to actuate the brake and to bring it into a corresponding engagement position. The resetting device has a recoil-prevention device to relieve recoil forces. The energy store can have a stop buffer to reduce the force impact when the energy store strikes an end position.

1 . An electromechanical actuator for attachment to a travel body of an elevator installation and for actuating an elevator brake of the travel body, the actuator comprising:
 an energy store;   a retaining device;   a resetting device;   a return lever; and   a connecting element connecting the actuator with the elevator brake,
 wherein the retaining device is arranged on the return lever and the return lever is connected to the resetting device, whereby the connection of the return lever to the resetting device includes a play, 
 wherein the resetting device acts, through the return lever and the retaining device, on the energy store and the connecting element to retain and/or return the energy store and the connecting element respectively to a first operating position corresponding with a readiness setting of the brake, 
 wherein the energy store upon release of the retaining device acts on the connecting element to actuate the brake into an applied setting, and 
 wherein a counter spring acts on the return lever to draw the return lever toward a first end of the play and forming thereby a spring-loaded recoil prevention device and relieving the resetting device of recoil forces. 
   
     
     
         2 . The actuator according to  claim 1  wherein the play in the connection of the return lever to the resetting device is formed by a guide pin arranged in a slot and the first end of the play is defined by an end of the slot. 
     
     
         3 . The actuator according to  claim 2  wherein the resetting device includes a return carriage and the slot is formed in the return carriage for co-operating with the guide pin arranged on the return lever. 
     
     
         4 . The actuator according to  claim 3  wherein the resetting device includes a spindle drive with a spindle nut arranged in the return carriage, a return spindle engaging the spindle nut being driven by a geared motor for forward and backward movement of the return carriage. 
     
     
         5 . The actuator according to  claim 3  wherein the counterspring urges the return lever together with the retaining device and the guide pin into a position corresponding with a force transmission direction of the recoil prevent device, and wherein a force action of the counterspring is small compared with a force action of the energy store. 
     
     
         6 . The actuator according to  claim 1  wherein the resetting device for resetting and retaining the actuator in the first operating position corresponding with the readiness setting of the brake acts on the retaining device by the recoil prevention device, wherein the recoil prevention device is constructed to transmit a force merely in one direction. 
     
     
         7 . The actuator according to  claim 1  wherein the energy store acts on the connecting element by a trigger lever and the trigger lever is held in a readiness setting at a connecting point of a retaining electromagnet arranged at the retaining device, wherein a fulcrum of the return lever and a fulcrum of the trigger lever are arranged on a common axis so that a pivot radius of the connecting point of the trigger lever and a retaining point of the retaining device are the same. 
     
     
         8 . The actuator according to  claim 7  wherein the connecting element is guided by the fulcrum of the trigger lever and the connecting element includes a connecting strap connected with the fulcrum of the trigger lever. 
     
     
         9 . The actuator according to  claim 1  wherein the energy store includes a first part, a second part and a first spring with a first spring tensioning force, wherein the first spring is tensioned between the first and second parts, wherein the first part and the second part are displaceable relative to one another over a displacement range and the displacement range is bounded by at least one of a front abutment and a rear abutment and the at least one abutment ensures a minimum first spring tensioning force, wherein an impact buffer is integrated into one of the first and second parts, and wherein the one of the first and second parts includes a first sub-member and a second sub-member and the impact buffer connects the first sub-member with the second sub-member. 
     
     
         10 . The actuator according to  claim 9  wherein the impact buffer includes a spring arrangement with a second spring tensioning force, which spring arrangement connects the first sub-member with the second sub-member and holds the first and second sub-members together, and wherein the second spring tensioning force is set to a greater value than the first spring tensioning force. 
     
     
         11 . The actuator according to  claim 10  wherein one of the first and second sub-members includes a threaded plate and another one of the first and second sub-members includes an impact plate and the spring arrangement tightens the impact plate relative to the threaded plate by a draw screw. 
     
     
         12 . The actuator according to  claim 9  wherein the first part is connected with the connecting element by a trigger lever, and the second part is connected with an actuator support, and wherein the second part includes a guide for the first part so that the first part is guided in and displaceable relative the second part. 
     
     
         13 . The actuator according to  claim 9  wherein the first part includes a further slot that co-operates with a guide pin of the second part and which determines the front and rear abutments that form the displacement range. 
     
     
         14 . The actuator according to  claim 9  wherein the first and second parts are pivotably connected by one of a trigger lever, the connecting element and an actuator support. 
     
     
         15 . An elevator installation with the travel body being one of an elevator car and a counterweight, the travel body having at least two of the elevator brakes and the electromechanical actuator according to  claim 15  coupled to the elevator brakes.