CENTRIFUGALLY ACTUATED MOTOR STARTING SWITCH APPARATUS

摘要

CENTRIFUGALLY ACTUATED MOTOR STARTING SWITCH A start switch connects a motor winding to a power supply, a contact plate supports a pair of fixed contact units on the opposite side of the motor shaft. Each contact includes an intetral cup-shaped enclosure having a generally U-shaped sidewall abutting the plate and an integral outer wall forming a continuous uninterrupted enclosure wall about the contacts. A fixed contact is secured to the outer wall. A multiple leaf spring has a center strip secured plate. U-shaped members on each side of the strip have an outer spring contact arm extending inwardly from a U-shaped base and in parallel relation to the strip. An integral contact tab extends from the contact arm into the U-shaped sidewall. A contact is secured to the tab in opposed relation to the fixed contact. An insulating actuator coupler is secured to the contact plate and deflecting the spring to create a torsional force on the tab contact. The coupler includes a side closure wall overlying the opening defined by the U-shaped wall and an end wall overlying the outer wall of the enclosure. The side closure wall engages the spring contact arm and locates the movable contact to establish a contact gap relative in the open switch position. The contact with the enclosure plate and coupler side closure wall is an essentially continuous enclosure about the contacts to confine the arc and its gases on contact opening, shield the arc from the surrounding magnetic field of the motor, and protect the contacts from airborne contaminants.