US Patent 11027438 Positive positioning device and system

A positive positioning device comprises a plurality of stacked plates, a body, a spring-biased piston and a piston release device. The plurality of stacked plates have a central opening defined to receive a pivot shaft. The body houses the plurality of stacked plates and has an internal bore within which a cylinder is defined. The spring-biased piston is shaped to slide within the bore to apply a force to the stacked plates to resist rotation of a pivot shaft inserted through the central opening in the stacked plates. The piston release device is actuatable by a user to release the piston to decrease force applied to the stacked plates and allow free rotation of the pivot shaft.