Patent US3680760A successfully refreshed from Google Patents.
US3680760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for inertia welding machines
Assignee: Caterpillar Inc
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Filing: 1970-04-17
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Granted: 1972-08-01
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Expires: 1990-04-17
Abstract
Abstract A control system for an inertial friction welding machine starts and accelerates an alternating current, induction drive motor to a preselected speed, senses the drive motor speed, automatically shuts-off power to the drive motor when the preselected speed is reached and signals a hydraulic control system to initiate and to terminate the welding sequence. The control system includes a DC link voltage control circuit, a frequency summing control circuit, a speed transducer, a control for setting the slip frequency, a wave-shaping and gate control unit and a silicon controlled rectifier inverter.
Inventors
- 👤 Philip Joseph Costa
- 👤 Caterpillar Tractor Co
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:20
CPC Classifications
B; B23; B23K; B23K20/00; B23K20/12; B23K20/121
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
96 words
A friction welder of the kind in which parts to be welded are pressed together in frictional rubbing contact and comprising, a rotatable spindle for rotating one of the parts to be welded, a tailstock for holding another part to be welded, loading means for engaging the parts under an axial load at their interface, an alternating current induction motor connected to rotate the spindle over a range of speeds, and power means for shaping a variable frequency fabricated wave of alternating current from direct current and connected to supply the fabricated wave to the motor.
Claim 2
Dependent Claim
96 words
A friction welder of the kind in which parts to be welded are pressed together in frictional rubbing contact and comprising, a rotatable spindle for rotating one of the parts to be welded, a tailstock for holding another part to be welded, loading means for engaging the parts under an axial load at their interface, an alternating current induction motor connected to rotate the spindle over a range of speeds, and power means for shaping a variable frequency fabricated wave of alternating current from direct current and connected to supply the fabricated wave to the motor.
Claim 3
Dependent Claim
33 words
A friction welder as defined in claim 1 wherein the power means include control apparatus effective to control the speed of the motor by changing the frequency of alternation of the fabricated wave.
Claim 4
Dependent Claim
122 words
A friction welder of the kind in which parts to be welded are pressed together in frictional rubbing contact and comprising, a rotatable spindle for rotating one of the parts to be welded, an alternating current induction motor connected to rotate the spindle over a range of speeds, and power means for shaping a variable frequency fabricated wave of alternating current from direct current and connected to supply the fabricated wave to the motor, said power means including control apparatus effective to control the speed of the motor by changing the frequency of alternation of the fabricated wave and wherein the control apparatus includes a slip control effective to produce a slip signal for regulating the amount of slip in the motor.
Claim 5
Dependent Claim
122 words
A friction welder of the kind in which parts to be welded are pressed together in frictional rubbing contact and comprising, a rotatable spindle for rotating one of the parts to be welded, an alternating current induction motor connected to rotate the spindle over a range of speeds, and power means for shaping a variable frequency fabricated wave of alternating current from direct current and connected to supply the fabricated wave to the motor, said power means including control apparatus effective to control the speed of the motor by changing the frequency of alternation of the fabricated wave and wherein the control apparatus includes a slip control effective to produce a slip signal for regulating the amount of slip in the motor.
Claim 6
Dependent Claim
116 words
A friction welder of the kind in which parts to be welded are pressed together in friction rubbing contact and comprising, a rotatable spindle for rotating one of the parts to be welded, an alternating current induction motor connected to rotate the spindle over a range of speeds, and power means for shaping a variablE frequency fabricated wave of alternating current from direct current and connected to supply the fabricated wave to the motor, said power means including control apparatus effective to control the speed of the motor by changing the frequency of alternation of the fabricated wave and wherein the power means include a voltage control for regulating the voltage level of the direct current.
Claim 7
Dependent Claim
116 words
A friction welder of the kind in which parts to be welded are pressed together in friction rubbing contact and comprising, a rotatable spindle for rotating one of the parts to be welded, an alternating current induction motor connected to rotate the spindle over a range of speeds, and power means for shaping a variablE frequency fabricated wave of alternating current from direct current and connected to supply the fabricated wave to the motor, said power means including control apparatus effective to control the speed of the motor by changing the frequency of alternation of the fabricated wave and wherein the power means include a voltage control for regulating the voltage level of the direct current.
Claim 8
Dependent Claim
26 words
A friction welder as defined in claim 3 wherein the control apparatus includes a transducer which produces a speed signal indicative of the spindle rotational speed.
Claim 9
Dependent Claim
47 words
A friction welder as defined in claim 5 wherein the control apparatus includes a summing circuit which combines the slip signal and the speed signal to produce a highly accurate output speed control signal at all speeds of the spindle from zero to high spindle rotational speeds.
Claim 10
Dependent Claim
88 words
A friction welder as defined in claim 5 wherein the power means include an inverter having an input connected to the direct current and an output connected to the motor, said inverter including two alternately fired rectifier circuits for each phase of power output to produce the alternation in the fabricate wave form, and wherein the power means also include a gating unit connected between the summing circuit and the inverter and effective to fire said rectifier circuits in alternation at a frequency determined by the summing circuit.
Claim 11
Dependent Claim
62 words
A friction welder as defined in claim 7 wherein each rectifier circuit includes a main silicon controlled rectifier and each gating unit includes a driver transformer, a programmable unijunction transistor and a Zenier and a resistance-capacitor combination connected across the secondary of the driver transformer for establishing the amplitude and pulse width of the firing signal for each main silicon controlled rectifier.
Claim 12
Dependent Claim
55 words
A friction welder as defined in claim 7 wherein the inverter includes main silicon controlled rectifiers, commutation silicon controlled rectifiers and an interconnection between the main silicon controlled rectifiers and the commutation silicon controlled rectifiers which is effective to fire the commutation silicon controlled rectifiers to cause shut off of the main silicon controlled rectifiers.
Claim 13
Dependent Claim
73 words
A friction welder as defined in claim 9 wherein the gating unit includes capacitors and gate firing circuits effective to put out two closely spaced signal spikes of short duration at each crossover point on a sine wave output from the control apparatus for shutting off the main silicon controlled rectifiers by letting the capacitors discharge and for causing charges to be stored in the capacitors for the next shut off control function.
Claim 14
Dependent Claim
23 words
A friction welder as defined in claim 10 wherein the gating unit includes means for producing a dead band at each crossover point.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |