Overforce protection mechanism

摘要

A overload protection mechanism protects a driven load, such as a driven lever. An overload lever is pivotally coupled to a first part of the driven load. The overload lever has a first end that receives an applied force and an opposing second end. A zero length spring mechanism is coupled to a second part of the driven load spaced apart from the first part and to the second end of the overload lever. The zero length spring mechanism urges the second end of the overload lever toward the second part of the driven load with a force that is substantially proportional to the distance between the second end of the overload lever and the second part of the driven load. A stop mechanism is coupled to the zero length spring mechanism to maintain a minimum distance between the second end of the overload lever and the second part of the driven load.

主权项

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.