Single phase t-r unit

Claim 2

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, a first alternating current power supply, a second alternating current power supply, a third alternating current power supply, means for establishing a main welding arc between the stud and the workpiece from the first power supply, means for establishing a sustaining arc between the stud and the workpiece from the second power supply before the main welding arc is established and for continuing the sustaining arc during the welding arc, means for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, a full wave rectifier in series with said third power supply, a blocking diode in series with said full wave rectifier, a filter capacitor in series with said blocking diode, said means for establishing the welding arc being connected with said blocking diode whereby pulsing DC power is applied to said means for establishing the welding arc, adjustable means for controlling the intensity of said welding arc, and means for enabling said plunging means to plunge the chuck toward the workpiece.

Claim 3

Apparatus for welding a chuck to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, a first alternating current power supply, a second alternating current power supply, a third alternating current power supply, means for establishing a main welding arc between the stud and the workpiece from the first power supply, means for establishing a sustaining arc between the stud and the workpiece from the second power supply before the main welding arc is established and for continuing the sustaning arc during the welding arc, means for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, a full wave rectifier in series with the third power supply, a blocking diode in series therewith, a filter capacitor in series with said blocking diode, said means for establishing the sustaining arc being connected to the blocking diode whereby substantially steady state DC power is applied to the means for establishing the sustaining arc, adjustable means for controlling the intensity of said welding arc, and means for enabling said plunging means to plunge the chuck toward the workpiece.

Claim 4

Apparatus for welding a chuck to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, a first alternating current power supply, a second alternating current power supply, a third alternating current power supply, means for establishing a main welding arc between the stud and the workpiece from the first power supply, means for establishing a sustaining arc between the stud and the workpiece from the second power supply before the main welding arc is established and for continuing the sustaning arc during the welding arc, means for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, a full wave rectifier in series with the third power supply, a blocking diode in series therewith, a filter capacitor in series with said blocking diode, said means for establishing the sustaining arc being connected to the blocking diode whereby substantially steady state DC power is applied to the means for establishing the sustaining arc, adjustable means for controlling the intensity of said welding arc, and means for enabling said plunging means to plunge the chuck toward the workpiece.

Claim 5

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, a first alternating current power supply, a second alternating current power supply, a third alternating curreNt power supply, means for establishing a main welding arc between the stud and the workpiece from the first power supply, means for establishing a sustaining arc between the stud and the workpiece from the second power supply before the main welding arc is established and for continuing the sustaining arc during the welding arc, means including said third power supply for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, adjustable means for controlling the intensity of said welding arc, and means for enabling said plunging means to plunge the chuck toward the workpiece, said means for enabling said plunging means to plunge the chuck toward the workpiece comprises a first SCR in series with a capacitor, both of which are in electrical parallel relation with an SCR of the welding tool, whereby actuation of the first SCR will cause the capacitor to discharge, reverse biasing the tool SCR when it is conducting.

Claim 6

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, a first alternating current power supply, a second alternating current power supply, a third alternating curreNt power supply, means for establishing a main welding arc between the stud and the workpiece from the first power supply, means for establishing a sustaining arc between the stud and the workpiece from the second power supply before the main welding arc is established and for continuing the sustaining arc during the welding arc, means including said third power supply for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, adjustable means for controlling the intensity of said welding arc, and means for enabling said plunging means to plunge the chuck toward the workpiece, said means for enabling said plunging means to plunge the chuck toward the workpiece comprises a first SCR in series with a capacitor, both of which are in electrical parallel relation with an SCR of the welding tool, whereby actuation of the first SCR will cause the capacitor to discharge, reverse biasing the tool SCR when it is conducting.

Claim 7

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, means for establishing a main welding arc between the stud and the workpiece, means for establishing a sustaining arc between the stud and the workpiece before the main welding arc is established and for continuing the sustaining arc during the welding arc, means for establishing a single phase alternating current power source, means for full wave rectifying power from said alternating current power source, control means for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, means for supplying full wave rectified power from said alternating current power source and said rectifying means to said control means, adjustable means for controlling the intensity of said welding arc, means for enabling said plunging means to plunge the chuck toward the workpiece, and means for filtering the full wave rectified power supplied to that portion of said control means which initiates said sustaining arc, including means for supplying a portion of the filtered full wave rectified power to said enabling means, the full wave rectified power supplied to that portion of said control means which initiates said welding arc after a delay being unfiltered.

Claim 8

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, means for establishing a main welding arc between the stud and the workpiece, means for establishing a sustaining arc between the stud and the workpiece before the main welding arc is established and for continuing the sustaining arc during the welding arc, means for establishing a single phase alternating current power source, means for full wave rectifying power from said alternating current power source, control means for initiating a welding cycle, including actuating said retracting means, initiating said sustaining arc, and initiating said welding arc after a delay, means for supplying full wave rectified power from said alternating current power source and said rectifying means to said control means, adjustable means for controlling the intensity of said welding arc, means for enabling said plunging means to plunge the chuck toward the workpiece, and means for filtering the full wave rectified power supplied to that portion of said control means which initiates said sustaining arc, including means for supplying a portion of the filtered full wave rectified power to said enabling means, the full wave rectified power supplied to that portion of said control means which initiates said welding arc after a delay being unfiltered.

Claim 9

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, means for establishing a first power source of single phase alternating current, control means connected with said first power source for establishing a sustaining arc between the stud and the workpiece when the stud is retracted from the workpiece by the retracting means, means for subsequently establishing a main welding arc between the stud and the workpiece while continuing the sustaining arc, said main welding arc means comprising a second single phase alternating current power source, phase delay control means for controlling the intensity of the main welding arc by phase delay control of the welding arc power, means establishing a third power source of full wave rectified alternating current, means for supplying filtered full wave rectified current from said third power source to said sustaining arc control means, and means for supplying unfiltered full wave rectified current from said third power source to said phase delay control means.

Claim 10

Apparatus for welding a stud to a workpiece comprising a welding tool having a chuck for holding a stud, means for retracting the chuck, and means for plunging the chuck toward the workpiece, means for establishing a first power source of single phase alternating current, control means connected with said first power source for establishing a sustaining arc between the stud and the workpiece when the stud is retracted from the workpiece by the retracting means, means for subsequently establishing a main welding arc between the stud and the workpiece while continuing the sustaining arc, said main welding arc means comprising a second single phase alternating current power source, phase delay control means for controlling the intensity of the main welding arc by phase delay control of the welding arc power, means establishing a third power source of full wave rectified alternating current, means for supplying filtered full wave rectified current from said third power source to said sustaining arc control means, and means for supplying unfiltered full wave rectified current from said third power source to said phase delay control means.