Elmwood Sensors, Inc.

Thomas H Bowder

Michael F Donais

A thermostatic switch has a contact arm which is adapted for reducing contact pressure and maximizing wiping action between fixed and movable contacts. The switch includes a housing, a pair of terminals mounted in the housing, a resilient contact arm connected to one of the terminals, a movable contact on the contact arm, a stationary contact connected to the other terminal, and an actuator assembly for opening and closing the switch. The contact arm is integrally struck from a resilient, electrically conductive metal and it includes a base portion, and a pair of supporting members extending outwardly and upwardly from the base portion and then bending back thereover merging into a main portion. The main portion includes a peripheral edge portion having a contact area, and a plurality of finger portions which converge inwardly therefrom and merge into an actuator portion. The actuator assembly communicates with the actuator portion of the contact arm for moving the contact arm from a normally biased open position, wherein the contacts are in spaced relation, through an intermediate position, wherein the contacts are in initial engagement, to a closed position, wherein the contacts are in at least slightly pressurized engagement and the actuator portion and the finger portions are deflected upwardly relative to the main portion, whereby a transverse wiping action is achieved between the contacts as the contact arm is moved from the intermediate position thereof to the closed position thereof.

Thermostatic switch and contact arm therefor

A thermally activated snap-action valve includes a valve body having an interior cavity and inlet and outlet passages formed therein and a bimetallic disc, a ball element, and a resilient positioning plate in the cavity. The positioning plate is operative for normally positioning the ball element in inwardly spaced relation to a valve seat at the inner end of the outlet passage, and the bimetallic disc is mounted in the cavity so that the pressures in a fluid passing through the valve are substantially equal on opposite sides of the bimetallic disc. The bimetallic disc is operative with a flexing action in response to a predetermined temperature condition for moving the ball element to a closed position wherein it is received in the valve seat to obstruct the outward flow of fluid through the outlet passage.

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Coventry, RI, United States of America

Thomas H Bowder