Motor starting device
AssigneeTexas Instruments Incorporated
InventorDouglas J. Slack
Life of this patent
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Abstract
A motor starting device for de-energizing the starting winding the required motor speed is reached comprising electromagnetic means (3) to urge actuation of the switching means (20,21) and a latch member (10) controlled by a thermal temperature-balanced bimetallic strip (5) to prevent switching until the bimetallic strip (5) reaches a selected temperature through current flow flow therethrough.
Claims16
A motor starting device adapted to de-energize a start winding, the device having a housing supporting an electromagnetic coil and switch means, characterized by a movable latch member connected between a keeper means of the electromagnetic coil and the switch means, the keeper having a portion movable toward and away from the electromagnetic coil and being operatively connected to the latch member to move the latch member, and a current carrying bimetallic strip mounted in the housing, the bimetallic strip having at least a portion movable between a first unheated position when no current is being carried and a second heated position when current is being carried, the bimetallic strip adapted to hold the latch member against displacement by the keeper means of the electromagnetic coil until the bimetallic strip is heated by current flow, the latch member having means to actuate the switching means upon selected movement of the latch member.
A motor starting device comprising a housing, an electromagnetic coil mounted in the housing, means to energize the coil, the coil having keeper means including a keeper element hingedly mounted so that a free end of the element can move toward and away from the coil, spring means urging the free end of the keeper element away fromn the coil, a latch member movably mounted in the housing adapted to move toward and away from the coil, the keeper element being disposed between the coil and the latch member, spring means urging the latch member toward the keeper element, a current carrying bimetallic strip having at least a portion movable between a first unheated position when the strip is not conducting current and a second heated position when the strip is conducting current, the movable portion adapted to be in engagement with the latch member in at least one of the first and second positions to prevent movement of the latch member while in engagement therewith, means to conduct current through the bimetallic strip, switch means comprising a movable switch blade mounted in the housing and means on the latch member to engage the movable switch blade to actuate the switch means.
Dependencies are inferred from the claim text.