Wirewound variable resistance control and method of making the same

Claim 2

A variable resistance control comprising a housing, a wirewound resistance element disposed in said housing, said resistance element comprising an insulating tape, a first piece and a second piece of metal spaced from the first piece bonded to the insulating tape, a resistance wire wound around the tape with adjacent turns spaced from each other, the first piece of metal shorting a plurality of the turns of the resistance wire at one end thereof to define a first shorted portion, the second piece of metal shorting a plurality of the turns of the resistance wire at the other end thereof to define a second shorted portion, said resistance wire having a single unshorted portion extending between the first and second shorted portions, a first end terminal electrically connected to said first shorted portion of the resistance wire, a second end terminal electrically connected to said second shorted portion of the resistance wire, a contactor comprising a pair of spaced fingers wipingly engaging the resistance element between the ends thereof, and a third terminal electrically connected with the contactor.

Claim 3

The control of claim 1, wherein an insulating core is disposed adjacent to the tape and the resistance wire is wound around the tape and the core.

Claim 4

The control of claim 1, wherein said first and second pieces of metal comprise copper with a clad exterior surface of nickel engaging the resistance wire.

Claim 5

The control of claim 1, wherein a bonding material having a lower softening temperature than the insulating tape is disposed between the metal and the tape, and said first and second pieces of metal are thermally bonded to the insulating tape.

Claim 6

The control of claim 4, wherein the insulating tape is a polyester tape and the bonding material is polyethylene.

Claim 7

The control of claim 5, wherein the polyethylene bonding material is a coating on the polyester insulating tape.

Claim 8

A variable resistance control comprising a housing, a wirewound resistance element disposed in said housing, said resistance element comprising an insulating core, an insulating tape in juxtaposition to the insulating core, a first piece and a second piece of metal foil spaced from the first piece bonded to the insulating tape, a resistance wire wound around the core and the tape with adjacent turns spaced from each other, the metal foil having a width substantially equal to the width of the tape, the first piece of metal foil shorting a plurality of the turns of the resistance wire at one end thereof to define a first shorted portion, the second piece of metal foil shorting a plurality of the turns of the resistance wire at the other end thereof to define a second shorted portion, said resistance wire having a single unshorted portion extending between the first and second shorted portions, a first end terminal electrically connected to said first shorted portion of the resistance wire, a second end terminal electrically connected to said second shorted portion of the resistance wire, a contactor comprising a pair of spaced fingers wipingly engaging the resistance element between the ends thereof, and a third terminal electrically connected with the contactor.

Claim 9

A variable resistance control comprising a housing, a wirewound resistance element disposed in said housing, said resistance element comprising an insulating core, an insulating tape in juxtaposition to the insulating core, a first piece and a second piece of metal foil spaced from the first piece bonded to the insulating tape, a resistance wire wound around the core and the tape with adjacent turns spaced from each other, the metal foil having a width substantially equal to the width of the tape, the first piece of metal foil shorting a plurality of the turns of the resistance wire at one end thereof to define a first shorted portion, the second piece of metal foil shorting a plurality of the turns of the resistance wire at the other end thereof to define a second shorted portion, said resistance wire having a single unshorted portion extending between the first and second shorted portions, a first end terminal electrically connected to said first shorted portion of the resistance wire, a second end terminal electrically connected to said second shorted portion of the resistance wire, a contactor comprising a pair of spaced fingers wipingly engaging the resistance element between the ends thereof, and a third terminal electrically connected with the contactor.

Claim 12

The method of claim 8, wherein the step of bonding pieces of metal to an insulating tape comprises the step of coating the insulating tape with a bonding material, securing an elongated strip of metal to the insulating tape wih the bonding material, and removing spaced pieces of metal bonded to the insulating tape to produce a laminated ribbon with precisely spaced pieces of metal.

Claim 13

The method of claim 9, wherein the insulating tape is a polyester and the bonding material is a polyethylene.

Claim 14

The method of claim 9, wherein the first mentioned spaced pieces of metal are removed by chemical etching.

Claim 15

The method of claim 9, wherein the step of securing an elongated strip of metal to the insulating tape includes the step of heating the bonding material until sufficiently soft to effect a bond between the metal and the tape.