Patent US3562485A successfully refreshed from Google Patents.
US3562485A
Expired / Lapsed
US
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Stud welding control circuit
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1968-05-08
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Granted: 1971-02-09
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Expires: 1988-05-08
Abstract
Abstract A solid state control circuit and alternating current power sources for stud welding apparatus are provided. The power sources include three-phase power for the pilot arc and singlephase power for the welding arc. The controls for stud welding apparatus where such power sources are utilized would be expected to be quite complex and costly. The controls according to the instant invention, however, are relatively simple and substantially no more involved than those heretofore employed with welding equipment using capacitors as the welding arc power source.
Inventors
- 👤 Paul A Glorioso
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:50
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/20; B23K9/205
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
131 words
A stud welding apparatus comprising, in combination a stud welding tool including a chuck for holding a stud, a solenoid for retracting the chuck, means for plunging the chuck towards a workpiece, a power supply for the welding arc deriving from an alternating current source, a power supply for a pilot arc, and a power supply for a control circuit, the control circuit including a transistor doubling as a switch and voltage regulator, first means for energizing the solenoid and for initiating a pilot arc between a stud and the workpiece, timing control means for controlling the duration of the pilot arc and for initiating a welding arc in timed relation with the welding arc power and control means, for initiating the plunge stroke of the stud, pilot arc being unsynchronized.
Claim 2
Dependent Claim
131 words
A stud welding apparatus comprising, in combination a stud welding tool including a chuck for holding a stud, a solenoid for retracting the chuck, means for plunging the chuck towards a workpiece, a power supply for the welding arc deriving from an alternating current source, a power supply for a pilot arc, and a power supply for a control circuit, the control circuit including a transistor doubling as a switch and voltage regulator, first means for energizing the solenoid and for initiating a pilot arc between a stud and the workpiece, timing control means for controlling the duration of the pilot arc and for initiating a welding arc in timed relation with the welding arc power and control means, for initiating the plunge stroke of the stud, pilot arc being unsynchronized.
Claim 3
Dependent Claim
52 words
A stud welding apparatus as set forth in claim 1 wherein the pilot arc circuitry has a pilot arc driving circuit comprising a blocking oscillator circuit including the inductance of a pulse coupling transformer primary, a switchable unidirectional device and a capacitor in parallel with the inductance through the switchable unidirectional device.
Claim 4
Dependent Claim
26 words
A stud welding apparatus as set forth in claim 1 wherein the pilot arc drive circuit is rendered operative by pulses from a unijunction relaxation oscillator.
Claim 5
Dependent Claim
29 words
A stud welding apparatus as set forth in claim 1 wherein the control circuit includes a free running unijunction timing circuit to control the duration of the pilot arc.
Claim 6
Dependent Claim
52 words
A stud welding apparatus as set forth in claim 1 wherein the control circuit includes a synchronizing circuit to produce a pulse to synchronize turn off of the solenoid and initiation of flow of welding current after a predetermined unsynchronized time period comprising a transistor connected in series with a pulse transformer.
References Cited (Backward Citations)
US3414701A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |