Motor protector calibratable by housing deformation having improved sealing and compactness

A protector for an electrical motor having start and run windings comprising

• a tubular housing of deformable, electrically and thermally conductive metal material having an open end and a closed end,
• a first contact button mounted directly on one side of the housing inside the housing adjacent the closed housing end
• a pair of terminals to be electrically connected to the respective motor windings mounted in the open housing end to extend into the housing adjacent to said one housing side and to an opposite side of the housing respectively in spaced, electrically insulated relation to each other and to the housing,
• a first electrical resistance heater secured in electrically conductive relation to the terminal adjacent said opposite housing side to extend in cantilever relation therefrom longitudinally along the length of the housing in spaced relation to the housing,
• a thermally-responsive electrically conductive bi-metallic member having one end secured in electrically conductive relation to said first heater to extend in cantilever relation therefrom with one side of the member extending in heat-transfer relation to a portion of the first heater for cooperating with the first heater in defining a substantial space located between the member and first heater and said one side of the housing, said member having a second contact at its opposite end normally engaged with said first contact for closing a circuit and being movable when heated to a selected temperature for disengaging the second contact from the first contact to open said circuit, and
• a second electrical resistance heater disposed in said substantial space electrically connected between the other terminal and said thermally responsive member, said second heater having a portion extending along an opposite side of the member in heat-transfer relation to the member and in spaced relation to said housing,
• whereby said heaters are compactly arranged in heat-transfer relation to the thermally responsive member to be connected in series with the respective motor windings for heating the member to open said circuit in response to the occurrence of selected current conditions in either of the windings while permitting deformation of the housing adjacent said closed end thereof for calibrating the protector.

An hermetically sealed thermally and electrically responsive protector device comprising, a tubular housing of deformable electrically and thermally conductive metal material having an open end and a closed end, terminal means mounted in the open housing end to extend into the interior of the housing in spaced electrically insulated relation to the housing, first contact means forming a first circuit component, and thermally responsive electrically conductive bimetallic means forming a second circuit component, one of said circuit components being mounted on the terminal means inside the housing in electrically conductive relation to the terminal means and the other circuit component being mounted on a single inner side of the housing inside the housing spaced from an opposite inner side of the housing near the closed end thereof in electrically conductive relation to the housing so that the bimetallic means extends in cantilever relation along the longitudinal axis of the tubular housing which extends between said open and closed ends of the tubular housing, said bimetallic means carrying second contact means for movement between a closed circuit position engaging the first contact means and an open circuit position disengaged from the first contact means to provide a selected electrically insulating spacing between the circuit components in said open circuit position in response to selected temperature change, said housing being deformable for modifying the relationship of said contact means to each other to calibrate the device characterized in that said other circuit component is welded to said single inner side of the housing spaced from said opposite inner side of the housing, and sealing means mount said terminal means in the open housing end in hermetically sealed and electrically insulated relation to the housing, thereby to permit said selected electrically insulating spacing of said circuit components in said open circuit position while more compactly accommodating the circuit components in the housing interior and while assuring retention of that hermetic sealing during housing deformation for device calibration.

An hermetically sealed thermally and electrically responsive protector device comprising a tubular housing of deformable, electrically and thermally conductive metal material having an open end and a closed end and having first contact means mounted on a side of the housing inside the housing spaced from an opposite inner side of the housing adjacent the closed housing end, terminal means mounted in the open housing end to extend into the interior of the housing in spaced, electrically insulated relation to the housing, and thermally responsive electrically conductive bimetallic means having one end secured in electrically conductive relation to said terminal means to extend in cantilever relation therefrom into the housing along the longitudinal housing axis which extends between said open and closed ends of the tubular housing, said bimetallic means having second contact means at its opposite end movable between a first position engaged with said first contact means for closing a circuit and a second position disengaged from the first contact means to open said circuit in response to selected temperature change to provide a selected electrically insulating spacing between said contact means in said open circuit position, said housing being deformable for calibrating the protector characterized in that said first contact means is welded to said single inner side of the housing spaced from said opposite inner side of the housing, and glass-sealing means mount said terminal means in the open housing end in hermetically sealed and electrically insulated relation to the housing thereby to permit said selected electrically insulating electrical spacing of said contact means in said open circuit position while more compactly accommodating the contact means and bimetallic means in the housing interior and while assuring retention of that hermetic sealing during housing deformation for device calibration.

An hermetically sealed thermally and electrically responsive protector for an electrical motor comprising a tubular housing of deformable, electrically and thermally conductive metal material having an open end and a closed end and having first contact means mounted on a single inner side of the housing inside the housing spaced from an opposite inner side of the housing adjacent the closed end, terminal means to be electrically connected to a winding of the motor mounted in the open housing end to extend into the housing in spaced, electrically insulated relation to the housing, an electrical resistance heater secured in electrically conductive relation to the terminal means to extend in cantilever relation therefrom along the length of the housing in spaced relation to the housing, and a thermally responsive electrically conductive bimetallic member having one end secured in electrically conductive relation to said heater to extend in cantilever relation therefrom along the longitudinal housing axis which extends between said open and closed ends of the tubular housing with one side of the member extending in heat-transfer relation to a portion of said heater, said member having second contact means at its opposite end normally engaged with said first contact means for closing a circuit and being movable when heated to a selected temperature for disengaging the second contact means from the first contact means to open said circuit to provide a selected electrically insulating spacing between said contact means in said open circuit position, said housing being deformable adjacent said closed end thereof for calibrating the protector characterized in that said first contact means is welded to said single inner side of the housing spaced from said opposite inner side of the housing, and glass-sealing means mount said terminal means in the open housing end in hermetically sealed and electrically insulated relation to the housing thereby to permit said selected electrically insulating electrical spacing of said contact means in said open circuit position while more compactly accommodating the contact means and bimetallic means in the housing interior and while assuring retention of that hermetic sealing during housing deformation for device calibration.