Plug with safety means for use with counterbalancing systems of garage doors and the like

Abstract

A plug mounted at one end of a torsional spring operatively connected to an overhead shaft of a counterbalancing mechanism of a garage door, wherein the plug comprises projecting interlocking means able to cooperate with corresponding matching means of a mating part of the counterbalancing mechanism, so that when the interlocking means of the plug are inserted into the corresponding matching means and when tension is applied to the torsional spring, the interlocking means interlock with said matching means of the mating part, thereby preventing the plug from being readily removed therefrom. The projecting interlocking means thus act as safety means because they provide an automatic locking mechanism which make the plug operate as a safety device as well. Hence, the plug according to the present invention has a dual purpose, that is, it can operate as a conventional plug, whether it be stationary or winding, as well as a safety device for the counterbalancing mechanism with which it cooperates, because of its projecting interlocking means.

Dependencies are inferred from the claim text.