Trigger speed control switch with plastic pack semi-conductor

Claim 2

A double-pole, variable control trigger switch comprising: a return spring biased trigger adapted for operation by the forefinger of the user; a frame mounting said trigger for movement therein and having a base-embracing portion; a split base held fixed within said base-embracing portion of said frame with the tops of the base halves continguous to said trigger and defining therebetween a central compartment and defining with said frame left and right compartments; double-pole switch means with one pole thereof in each said left and right compartment and means for operating said switch poles by said trigger; and a semi-conductor variable control circuit in said central compartment comprising: a plastic pack semi-conductor element having cathode and gate terminals; a resistor strip at the top of said central compartment; an elongated connector disposed alongside said resistor strip and being electrically connected to the anode of said semiconductor element; an electrical contact driven by said trigger to slide along said resistor strip and said connector to vary the amount of resistance in said variable control circuit; a capacitor connected across said cathode and gate terminals; and means for connecting said variable control circuit to said double-pole switch means and to an electric power source and load.

Claim 3

The switch defined in claim 1, wherein: said capacitor is a chip capacitor electrically connected directly to bridge said cathode and gate terminals.

Claim 4

The switch defined in claim 1, wherein: said capacitor is a ceramic capacitor having a pair of wire leads connected between said cathode and gate terminals.

Claim 5

The switch defined in claim 1, wherein: said elongated connector is a T-shaped member having its lower portion secured to said anode of said semi-conductor element to suspend the latter in said central compartment.

Claim 6

The switch defined in claim 1, wherein: said plastic pack semi-conductor also comprises a mounting tab serving as the anode terminal thereof; and said elongated connector is a T-shaped member having its lower portion connected to said mounting tab of said semi-conductor element to support the latter in said central compartment.

Claim 7

The switch defined in claim 1, wherein: said elongated connector comprises an edge of a mounting tab that is an integral part of said plastic pack semi-conductor element which mounting tab serves also as the anode terminal thereof.

Claim 8

A double-pole, speed control trigger switch comprising: a frame having a trigger retaining portion and a base-embracing portion; a trigger mounted in said trigger retaining portion for reciprocal movement; a return spring biasing said trigger into an extended position from which it may be depressed by the forefinger of the user; a split base held clamped within said base-embracing portion of said frame with the tops of the base halves underlying said trigger, said base halves defining therebetween a central compartment and defining with said base-embracing portion of said frame left and right compartments; a double-pole switch having its two poles in said left and right compartments, respectively; means on said trigger for operating said switch poles, and a semi-conductor speed control circuit in said central compartment comprising: a plastic pack SCR having an anode, a cathode and a gate, said cathode and gate being connected to terminals projecting from said plastic pack SCR; a resistor strip at the top of said central compartment; an elongated connector in parallel spaced relation to said resistor strip and being electrically connected to said anode of said SCR; a bridging contact driven by said trigger to slide along said resistor strip and said connector to vary the resistance in circuit; a capacitor connected across said cathode and gate terminals to be charged through said variable resistor strip; and means for connecting said speed control circuit to said double-pole switch and an A.C. power source and a portable tool motor.

Claim 9

A double-pole, speed control trigger switch comprising: a frame having a trigger retaining portion and a base-embracing portion; a trigger mounted in said trigger retaining portion for reciprocal movement; a return spring biasing said trigger into an extended position from which it may be depressed by the forefinger of the user; a split base held clamped within said base-embracing portion of said frame with the tops of the base halves underlying said trigger, said base halves defining therebetween a central compartment and defining with said base-embracing portion of said frame left and right compartments; a double-pole switch having its two poles in said left and right compartments, respectively; means on said trigger for operating said switch poles, and a semi-conductor speed control circuit in said central compartment comprising: a plastic pack SCR having an anode, a cathode and a gate, said cathode and gate being connected to terminals projecting from said plastic pack SCR; a resistor strip at the top of said central compartment; an elongated connector in parallel spaced relation to said resistor strip and being electrically connected to said anode of said SCR; a bridging contact driven by said trigger to slide along said resistor strip and said connector to vary the resistance in circuit; a capacitor connected across said cathode and gate terminals to be charged through said variable resistor strip; and means for connecting said speed control circuit to said double-pole switch and an A.C. power source and a portable tool motor.

Claim 10

The switch defined in claim 7, wherein: said elongated connector is a mounting tab on said plastic pack SCR formed so that its edge lies alongside said resistor strip.

Claim 11

The switch defined in claim 7, wherein: said plastic pack SCR also has a mounting tab formed integrally therewith and serving as its anode terminal and is a sensitive-gate type; and said elongated connector comprises a metal member having a formed strip lying alongside said resistor strip whereby it is supported at the top of said central compartment, and a lower portion rigidly secured to said mounting tab.

Claim 12

The switch defined in claim 7, wherein: said capacitor comprises a chip connected directly across said cathode and gate terminals so as to eliminate wire connections therebetween.