DAMPING SYSTEM FOR MECHANICAL SHUTTER

摘要

A damping system for an electromagnetically operable shutter (10) includes a detent (40) for arresting the motion of a pivotally supported shutter actuating drive arm (24). The detent (40) has damper portions (68A and 68B) that are fixed to the pivotally supported drive arm (24) and bumper portions (36) that are fixed to positions to receive the impact of the dampers as the arm is pivoted in one direction or another to operate the shutter. The damper portions (68A and 68B) each have a straight edge (70) and the surface of each bumper portion (36) is curved so as to maintain substantially a point contact between the two throughout the duration of the impact. In addition the damper portions are formed of damped polyurethane and each bumper portion is formed of an ultra high molecular weight polyethylene, the combination of materials providing energy absorption while avoiding the adherence of damper and bumper portions upon impact.