Solid state electrical switch

Claim 2

A solid state electrical device comprising a cup-shaped casing of dielectric material having a bottom and a sidewall forming a casing chamber having an open end, a first electrically conductive metal terminal means disposed in the casing having a resilient spring portion bearing against said casing bottom and having a connector portion extending through said casing sidewall, a ceramic resistor element of positive temperature coefficient of resistivity disposed within said casing resting on and in electrical engagement with said first terminal means, and a second electrically conductive metal terminal means having a heat-dissipating plate portion closing said open casing end and electrically engaging said resistor element, said second terminal means having at least one tab portion extending through said casing toward said casing bottom and having an enlarged end on said tab portion engaging said casing exteriorly of said casing chamber holding said first and second terminal means pressed resiliently in electrical engagement with said resistor element and securing said terminal means and resistor element with respect to said casing with said first terminal means pressed resiliently against said casing bottom.

Claim 3

A solid State electrical switch comprising a cup-shaped casing of dielectric material having a bottom and a sidewall forming a casing chamber having an open end and a rim around said open end, said casing having a slotted portion at said rim and having a plurality of apertures opening at said casing bottom, a first electrically conductive metal terminal disposed in the casing having a resilient spring portion bearing against said casing bottom and having a connector portion extending exteriorly of said casing chamber through said slotted portion of said rim, a resistor disc of a ceramic material of positive temperature coefficient of resistivity adapted to be electrically self-heated by directing electrical current therethrough and to display a sharp increase in resistivity when self-heated to a selected temperature for limiting said heating, said resistor disc having contact surfaces on opposite disc sides thereof and being disposed in said casing chamber on and with one of said contact surfaces in electrical engagement with said first terminal, and a second electrically conductive metal terminal having a heat-dissipating plate portion closing said open casing end and electrically engaging the other of said contact surfaces on said resistor disc, having a connector portion extending exteriorly of said casing chamber through said slotted portion of said rim, and having a plurality of tabs extending through said respective casing apertures, said tabs being enlarged at their distal ends to engage said casing exteriorly thereof holding said first and second terminals pressed resiliently in electrical engagement with said resistor disc and securing said terminals and disc to said casing with said first terminal pressed resiliently against said casing bottom.

Claim 4

A solid State electrical switch comprising a cup-shaped casing of dielectric material having a bottom and a sidewall forming a casing chamber having an open end and a rim around said open end, said casing having a slotted portion at said rim and having a plurality of apertures opening at said casing bottom, a first electrically conductive metal terminal disposed in the casing having a resilient spring portion bearing against said casing bottom and having a connector portion extending exteriorly of said casing chamber through said slotted portion of said rim, a resistor disc of a ceramic material of positive temperature coefficient of resistivity adapted to be electrically self-heated by directing electrical current therethrough and to display a sharp increase in resistivity when self-heated to a selected temperature for limiting said heating, said resistor disc having contact surfaces on opposite disc sides thereof and being disposed in said casing chamber on and with one of said contact surfaces in electrical engagement with said first terminal, and a second electrically conductive metal terminal having a heat-dissipating plate portion closing said open casing end and electrically engaging the other of said contact surfaces on said resistor disc, having a connector portion extending exteriorly of said casing chamber through said slotted portion of said rim, and having a plurality of tabs extending through said respective casing apertures, said tabs being enlarged at their distal ends to engage said casing exteriorly thereof holding said first and second terminals pressed resiliently in electrical engagement with said resistor disc and securing said terminals and disc to said casing with said first terminal pressed resiliently against said casing bottom.

Claim 5

A switch as set forth in claim 2 wherein said second terminal has at least one tab portion upstanding from said plate portion thereof forming an additional connector portion of said second terminal.

Claim 6

A switch as set forth in claim 2 wherein said casing sidewall has a groove extending around a substantial part of said sidewall adjacent said rim forming a shoulder within said casing chamber and said plate portion of said second terminal is held in engagement with said shoulder for closing said open casing end.

Claim 7

A switch as set forth in claim 4 wherein said casing apertures extend through said casing sidewall from said shoulder to said casing bottom.

Claim 8

A switch as set forth in claim 2 wherein said connector portions of said first and second terminals comprise slit metal sleeves extending from said terminals to receive leads within said sleeves.

Claim 9

A switch as set forth in claim 6 wherein said casing has an additional wall portion upstanding from said casing bottom adjacent said slotted portion of said casing rim engaging one end of each of said connector sleeves of said first and second terminals for further securing said terminals in selected portions relative to said casing.

Claim 10

A switch as set forth in claim 7 having an insulator member held between said connector sleeve of said first terminal and said second terminal and between said sidewall and additional wall of said casing.

Claim 11

A switch as set forth in claim 2 wherein said first terminal has a plate portion engaging a surface of said resistor disc and has a plurality of integral spring portions extending from said first terminal plate portion resiliently engaging said casing bottom.

Claim 12

A solid state electrical switch comprising a cup-shaped casing of dielectric material having a bottom and a sidewall forming a casing chamber having an open end and a rim around said open end, said casing having a slotted portion at said rim, having an additional wall upstanding from said casing bottom adjacent said slotted rim portion, having a groove in said sidewall adjacent said rim forming a shoulder within said casing chamber extending around a substantial part of said sidewall, and having a plurality of apertures extending through said sidewall from said shoulder to said casing bottom, a first electrically conductive metal terminal having a plate portion, having a plurality of integral spring portions extending from said plate portion resiliently engaging said casing bottom, and having a split sleeve connector portion extending through said slotted portion of said rim and engaged by said additional casing wall for positioning said first terminal within said casing chamber, a resistor disc of ceramic material of positive temperature coefficient of resistivity adapted to be electrically self-heated by directing electrical current therethrough and to display a sharp increase in resistivity when self-heated to a selected temperature for limiting said heating, said resistor disc having contact surfaces on opposite sides thereof and being disposed in said casing chamber with one of said contact surfaces resting on and in electrical engagement with said first terminal plate portion, and a second electrically conductive metal terminal having a heat-dissipating plate portion resting on said casing shoulder closing said open casing end and electrically engaging the other of said resistor disc contact surfaces, having a split sleeve connector portion extending through said slotted portion of said rim and engaged by said additional casing wall, and having a plurality of tabs extending through said casing apertures, said tabs being enlarged at their extended ends engaging said casing exteriorly thereof holding said first and second terminals pressed resiliently in electrical engagement with said resistor disc and securing said terminals and disc to said casing with said first terminal pressed resiliently against said casing bottom.

Claim 13

A solid state electrical switch comprising a cup-shaped casing of dielectric material having a bottom and a sidewall forming a casing chamber having an open end and a rim around said open end, said casing having a slotted portion at said rim, having an additional wall upstanding from said casing bottom adjacent said slotted rim portion, having a groove in said sidewall adjacent said rim forming a shoulder within said casing chamber extending around a substantial part of said sidewall, and having a plurality of apertures extending through said sidewall from said shoulder to said casing bottom, a first electrically conductive metal terminal having a plate portion, having a plurality of integral spring portions extending from said plate portion resiliently engaging said casing bottom, and having a split sleeve connector portion extending through said slotted portion of said rim and engaged by said additional casing wall for positioning said first terminal within said casing chamber, a resistor disc of ceramic material of positive temperature coefficient of resistivity adapted to be electrically self-heated by directing electrical current therethrough and to display a sharp increase in resistivity when self-heated to a selected temperature for limiting said heating, said resistor disc having contact surfaces on opposite sides thereof and being disposed in said casing chamber with one of said contact surfaces resting on and in electrical engagement with said first terminal plate portion, and a second electrically conductive metal terminal having a heat-dissipating plate portion resting on said casing shoulder closing said open casing end and electrically engaging the other of said resistor disc contact surfaces, having a split sleeve connector portion extending through said slotted portion of said rim and engaged by said additional casing wall, and having a plurality of tabs extending through said casing apertures, said tabs being enlarged at their extended ends engaging said casing exteriorly thereof holding said first and second terminals pressed resiliently in electrical engagement with said resistor disc and securing said terminals and disc to said casing with said first terminal pressed resiliently against said casing bottom.

Claim 14

A switch as set forth in claim 10 wherein said first terminal has a portion engaging said casing sidewall for positioning said first terminal within said casing.