Pre-Loaded Dual Rate Beam Spring
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
A plastic print wheel has a first force exerted on it by a pre-loaded dual rate beam spring when a cartridge, which has the print wheel mounted therein, is stored outside of a machine and a second and higher force exerted thereon when the print wheel is mounted on a motor shaft of the machine for rotation of the print wheel. This low spring force, when the cartridge is stored out of the machine, prevents excessive loading that could cause creep deformation of the plastic print wheel. A plastic print wheel 1 is disposed within a cartridge 2 and has a beam spring 3 acting against its hub 4. The beam spring 3 has openings 5 adjacent each end for disposition over bosses 6 extending from a wall 7 of the cartridge 2. The bosses 6 cause pre-loading of the spring 3 through expanding the length of the spring 3.