The present invention relates to elevator braking systems and more particularly to a self locking assembly for elevator braking systems.
In certain instances, an elevator car may be caused to stop between building floors due to power failure, for example, whereupon it may be necessary to lock the elevator brake to allow the exit of any passengers. It is important that elevator brake system remain in a locked condition unavailable to release by the general public.
It has been proposed, in elevators that use a cable brake release system actuated by a handle to make the handle removable and lock the handle with a padlock, for example, to prevent the general public from releasing the brake. In such a system, the handle may be left in place allowing the car to be moved; the handle may be misplaced or lost; or the padlock misplaced during the time the elevator system was being serviced.
It is an object of the present invention to produce a brake release system for elevator systems that is accessible only by trained elevator personnel.
Another object of the invention is to produce a self locking elevator braking system including a brake handle wherein a key is needed to release the brake handle and will automatically lock the handle against movement before the elevator mechanic leaves the vicinity of the locking system.
Other objectives and advantages of the invention may typically be achieved by a self locking elevator brake comprising: an elevator drive brake element rotatable between a brake reset position and a brake released position; a handle attached to said brake element for moving between a locked position wherein said brake element is in said brake reset position and an unlocked position wherein said brake element is in said brake released position, said handle having a latch receiving aperture formed therein; and a selectively operated locking means for maintaining said handle in said locked position, said locking means including a latching plunger releasably engaging said latch receiving aperture when said handle is in said locked position.
The above objects and advantages of the invention will become readily apparent to those skilled in the art from reading the following detailed description of a preferred embodiment of the invention when considered in the light of the accompanying drawings, in which:
Referring to the drawings, there is illustrated a self locking elevator brake actuating element 10 including an elongate handle 12 having one end affixed to a brake element such as a drum 14 mounted to rotate about an axis 16. The drum 14 is an integral portion of the elevator car drive braking system which may be in the form of the system illustrated and described in U.S. Pat. No. 5,971,109, for example. The handle 12 is provided with a latch receiving aperture 18, as clearly shown in
Normally, the handle 12 is in a locked position within a lock assembly 20 as illustrated in
It will be appreciated that with the illustrated embodiment of the invention, a safety switch contact 32 may be mounted within the recess 24 as illustrated in
Further, in order to facilitate the depression of the plunger 26, a leading edge 34 of the handle 12 may be rounded or beveled to assist in camming the plunger 26 and causing the same to slide against the bias of an operating spring.
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 understood that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.