An improved mounting bracket is closed which can be used to selectively support both 4 inch square electric boxes and 411/16 inch square electrical boxes such that vertical movement of either type of electrical box is limited. The mounting bracket is preferably a one-piece, unitary member stamped from...http://www.google.fr/patents/US6209836?utm_source=gb-gplus-shareBrevet US6209836 - Electrical box mounting bracket
