Patent ID: 8991278
Filing Date: 2015-03-31
Classification: G05G,Y10S,Y10T

Abstract:
1. An overload protection mechanism comprising: a driven lever having a first end and an opposite second end, the driven lever being supported at a first pivot between the first end and the second end of the driven lever; an overload lever having a third end and an opposite fourth end, the overload lever being pivotally coupled to the first end of the driven lever at a second pivot between the third end and the fourth end of the overload lever, the overload lever being positioned to receive an applied force at the third end of the overload lever; a zero length spring mechanism coupled to the fourth end of the overload lever and to a third pivot on the driven lever at a fixed distance apart from the second pivot and the fourth end of the overload lever, the zero length spring mechanism urging the fourth end of the overload lever toward the third pivot on the driven lever with a force that is substantially proportional to a distance between the fourth end of the overload lever and the third pivot on the driven lever; and a stop mechanism coupled to the zero length spring mechanism, the stop mechanism maintaining a minimum distance between the fourth end of the overload lever and the third pivot on the driven lever to provide a preload force that acts against the applied force to prevent rotation of the overload lever when the applied force is less than the preload force.