US4456810A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adaptive schedule selective weld control
Assignee: Ford Motor Co
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Filing: 1982-03-29
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Granted: 1984-06-26
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Expires: 2002-03-29
Abstract
Abstract A spot weld control senses differences in welding current required to produce an optimum weld by determining the time rate of change of resistance during the increasing resistance portion of the weld cycle. The weld control can reduce the welding current if the time rate of resistance change exceeds a maximum value and increase the current if the resistance change is less than a minimum value. The weld current may be terminated when a decrease in resistance from the peak resistance value has reached a predetermined percentage of the peak resistance value or terminated after a predetermined number of current cycles.
Inventors
- 👤 Berthold W. Schumacher
- 👤 Walter Dilay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:41
CPC Classifications
B; B23; B23K; B23K11/00; B23K11/24; B23K11/25; B23K11/252; B23K11/256; B23K11/16; B23K11/163; B23K11/166
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
107 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes during the first several cycles of welding current in which the resistance increases steadily that are supplied immediately following the first few cycles of welding current during which the resistance changes unstably and without a steady trend; and increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate.
Claim 2
Independent Claim
107 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes during the first several cycles of welding current in which the resistance increases steadily that are supplied immediately following the first few cycles of welding current during which the resistance changes unstably and without a steady trend; and increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate.
Claim 3
Dependent Claim
70 words
The method of claim 1 further comprising: continuously determining the time rate of resistance change occurring between successive welding current cycles; and increasing the magnitude of the welding current if the most recently determined time rate of resistance rise is less than a preselected minimum rate or decreasing the magnitude of the welding current if the most recently determined time of resistance rise is greater than a preselected maximum rate.
Claim 4
Dependent Claim
37 words
The method of claim 2 further comprising discontinuing the supply of electric current to the electrodes if the resistance has decreased by a predetermined magnitude from the maximum resistance attained after the weld has begun to form.
Claim 5
Dependent Claim
37 words
The method of claim 1 further comprising discontinuing the supply of electric current to the electrodes if the resistance has decreased by a predetermined magnitude from the maximum resistance attained after the weld has begun to form.
Claim 6
Dependent Claim
31 words
The method of claim 1 wherein the time rate of resistance change is determined from the resistance across the electrodes when the time rate of weld current change is substantially zero.
Claim 7
Independent Claim
173 words
A method for making electrical resistance welds using a spot welder having electrodes and a controllable electrical welding current supplied to the electrodes comprising: inserting the workpiece between the electrodes; supplying alternating welding current to the electrodes; determining the time rate of increase of resistance across the electrodes during each of the first several cycles of welding current in which the resistance increases steadily that are supplied immediately following the first few cycles of welding current supplied to the electrodes in which the resistance changes unstably and without a steady trend; and increasing the magnitude of welding current by an amount that varies with the difference between the determined time rate of resistance increase and a preselected rate if the determined time rate of resistance rise is less than the preselected rate, or reducing the magnitude of welding current by an amount that varies with the difference between the determined time rate of resistance increase and the preselected rate if the determined time rate of resistance increase is greater than the preselected rate.
Claim 8
Independent Claim
173 words
A method for making electrical resistance welds using a spot welder having electrodes and a controllable electrical welding current supplied to the electrodes comprising: inserting the workpiece between the electrodes; supplying alternating welding current to the electrodes; determining the time rate of increase of resistance across the electrodes during each of the first several cycles of welding current in which the resistance increases steadily that are supplied immediately following the first few cycles of welding current supplied to the electrodes in which the resistance changes unstably and without a steady trend; and increasing the magnitude of welding current by an amount that varies with the difference between the determined time rate of resistance increase and a preselected rate if the determined time rate of resistance rise is less than the preselected rate, or reducing the magnitude of welding current by an amount that varies with the difference between the determined time rate of resistance increase and the preselected rate if the determined time rate of resistance increase is greater than the preselected rate.
Claim 9
Dependent Claim
37 words
The method of claim 6 further comprising discontinuing the supply of electric current to the electrodes if the resistance has decreased by a predetermined magnitude from the maximum resistance attained after the weld has begun to form.
Claim 10
Dependent Claim
37 words
The method of claim 6 wherein the magnitude of the welding current is continuously increased or decreased after each cycle of weld current during which the time rate of increase of resistance across the electrodes is determined.
Claim 11
Independent Claim
125 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes after the resistance has stabilized; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate; supplying a few cycles of low magnitude current to the electrodes before current at welding magnitude is supplied; and discontinuing the supply of current to the electrodes for a period of several power cycles while maintaining the workpiece in location between the electrodes and before current at welding magnitude is supplied.
Claim 12
Independent Claim
125 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes after the resistance has stabilized; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate; supplying a few cycles of low magnitude current to the electrodes before current at welding magnitude is supplied; and discontinuing the supply of current to the electrodes for a period of several power cycles while maintaining the workpiece in location between the electrodes and before current at welding magnitude is supplied.
Claim 13
Independent Claim
130 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; continuously determining the time rate of resistance change across the electrodes occurring between successive welding current cycles; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected minimum rate or decreasing the magnitude of the welding current if the most recently determined time of resistance rise is greater than a preselected maximum rate; supplying a few cycles of low magnitude current to the electrodes before current at welding magnitude is supplied; and discontinuing the supply of current to the electrodes for a period of several power cycles while maintaining the workpiece in location between the electrodes and before current at welding magnitude is supplied.
Claim 14
Independent Claim
130 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; continuously determining the time rate of resistance change across the electrodes occurring between successive welding current cycles; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected minimum rate or decreasing the magnitude of the welding current if the most recently determined time of resistance rise is greater than a preselected maximum rate; supplying a few cycles of low magnitude current to the electrodes before current at welding magnitude is supplied; and discontinuing the supply of current to the electrodes for a period of several power cycles while maintaining the workpiece in location between the electrodes and before current at welding magnitude is supplied.
Claim 15
Independent Claim
130 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes after the resistance has stabilized; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate; and discontinuing the supply of electric current to the electrodes if the rate of change of the time rate of resistance rise twice becomes substantially zero after the resistance has stabilized, provided said rate of change becomes substantially other than zero during a period occurring between the periods when said rate of change is substantially zero.
Claim 16
Independent Claim
130 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes after the resistance has stabilized; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate; and discontinuing the supply of electric current to the electrodes if the rate of change of the time rate of resistance rise twice becomes substantially zero after the resistance has stabilized, provided said rate of change becomes substantially other than zero during a period occurring between the periods when said rate of change is substantially zero.
Claim 17
Independent Claim
142 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes after the resistance has stabilized and while the time rate of weld current change is substantially zero; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate; and discontinuing the supply of electric current to the electrodes if the rate of change of the time rate of resistance rise twice becomes substantially zero after the resistance has stabilized, provided said rate of change becomes substantially other than zero during a period occurring between the periods when said rate of change is substantially zero.
Claim 18
Independent Claim
142 words
A method for welding a workpiece located between electrodes comprising: supplying alternating welding current to the electrodes; determining the time rate of rise of resistance across the electrodes after the resistance has stabilized and while the time rate of weld current change is substantially zero; increasing the magnitude of the welding current if the time rate of resistance rise is less than a preselected rate or reducing the magnitude of the welding current if the time rate of resistance rise is greater than a preselected rate; and discontinuing the supply of electric current to the electrodes if the rate of change of the time rate of resistance rise twice becomes substantially zero after the resistance has stabilized, provided said rate of change becomes substantially other than zero during a period occurring between the periods when said rate of change is substantially zero.
References Cited (Backward Citations)
US2848595A
Cited
US3408473A
Cited
US3335258A
Cited
US3409755A
Cited
US3345493A
Cited
US3422243A
Cited
US3518399A
Cited
US3573421A
Cited
US3588438A
Cited
US3586815A
Cited
US3774006A
Cited
US3654424A
Cited
US3899653A
Cited
US4302653A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |