摘要 |
An automatic door closer for a sliding door. The closer has a reel with a cable extending around a pulley on the end of the rod of a return mechanism. In preferred embodiments, the return mechanism is an oil dammed gas spring or a magnetic spring. A spool rotates on a common shaft with the reel and is wound with a flat tape which is attached to the door frame. The reel, spool, return mechanism and cable are attached to the door so that application of an opening force will cause the cylinder rod to retract. Upon release, the stored energy will cause the rod to extend, rotating the reel and spool to wind the tape onto the spool applying a controlled rate closing force. The spool has a core with a greater diameter than the core of the reel so a mechanical advantage exists between the spool and reel and friction is reduced. |