HIGH ENERGY TRANSFER RELAY

摘要

A high energy transfer relay (11) ideally suited for transmitting high energy cardiac defibrillation pulses to a pair of electrodes placed on a patient is disclosed. The relay includes a housing (13), a solenoid (15), a pivot arm (17), a stationary contact (21), a switching contact (19), and a retraction spring (23). The switching contact (19) is mounted on the retraction spring (23). The armature (47) of the solenoid (15) is coupled to the pivot arm (17) such that when the coil (45) of the solenoid (15) is energized, the pivot arm (17) moves in the direction of the stationary contact (21). Movement is against the force of the retraction spring (23) which is positioned to bias the pivot arm (17) away from the stationary contact (21) against a stop (99). The retraction spring (23) also pre-loads the pivot point. In addition to biasing and preloading the pivot arm (17) in the open position when the coil (45) of the solenoid (15) is not energized, the resilience of the retraction spring (23) cushions the impact of the switching contact (19) on the stationary contact (21) to help prevent contact bounce. The outer end of the pivot arm (17) includes a flat (101) that coacts with flat wall (55) when the switching contact (19) is moved toward the stationary contact (21). The flat area creates an air cushion after the switching contact (19) mates with the stationary contact (21). The air cushion also assists in preventing contact bounce by absorbing the momentum of the pivot arm (17) after the switching contact (19) engages the stationary contact (21). Additionally, the moment of inertia of the pivot arm (17) and associated elements located on the switching contact (19) side of the pivot point (89) is counterbalanced by the moment of inertia of the armature (47) of the solenoid (15) and the part of the pivot arm (17) on the solenoid (15) side of the pivot point (89). Balancing the moment of inertia of the pivot arm (17) on the switching contact (19) side with the moment of inertia on the solenoid (15) side ensures that when an acceleration force is applied to the armature (47) and the part of the pivot arm (17) on the solenoid (15) side of the pivot point (89), an equal and opposite force is applied to the switching contact (19) side of the pivot arm (17).