A one or two sided or headed ratcheting driving wrench. Each side or head has a rotatable tool carrier constrained to rotate in only one direction by interengaging teeth formed in the tool carrier and in its housing. Both sets of teeth may be pointed or rounded. In one direction, torque locks the tool...http://www.google.de/patents/US5996453?utm_source=gb-gplus-sharePatent US5996453 - Ratchet mechanism which resists spontaneous disengagement for use in wrenches and other tools
