TORSION BAR COUNTERBALANCE MECHANISM
Original Publication Date: 1993-Aug-31
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
Disclosed is a low cost and space saving counter-balance mechanism for counter-balancing heavy objects such as a recirculating document handler (RDH) in xerographic copiers. Counter-balance mechanism 2, which consists of two torsion bars 3 and 4 coupled via gearset 5, having gears 6 and 7, is shown in Figure 1. The overall length (L/2) of the counter-balance 2 is reduced by placing the torsion bars 3 and 4 side-by-side. The disclosed low cost counter-balance mechanism design solves two problems frequently associated with a torsion bar type counter-balance design. First, long span length is reduced by a factor of two (or more) through the use of gearset 5 that couples folded torsion bar spans 3 and 4. Second, the spring rate is precisely adjustable by moving the location of mating gear pair 6 and 7.