US3708648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-mode structural spotweld monitor
Assignee: Lockheed Martin Corp
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Filing: 1971-06-18
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Granted: 1973-01-02
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Expires: 1991-06-18
Abstract
Abstract Disclosed herein is a multi-mode spotweld monitor which selectively monitors one or more of a plurality of different weld quality indicators. Provision is made for the recording of the indicators in both analog and digital form to provide readily usable data for weld quality determinations. Further, the multimode monitor need not be adjusted to compensate for variations in the thickness of different workpieces and/or for variations in electrode lengths due to wear.
Inventors
- 👤 W Croucher
- 👤 R Chihoski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:00
CPC Classifications
B; B23; B23K; B23K11/00; B23K11/24; B23K11/25; B23K11/252
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
177 words
A weld monitor system for tracking the separation between a pair of welder electrodes, at least one of which is movable, a workpiece being positioned therebetween, the expansion, melting and solidification of the workpiece during a weld cycle causing variations in electrode separation, comprising; a. means for producing an output potential proportional to electrode separation, b. analog recorder means for recording said potential proportional to electrode separation, c. first and second storage means for storing potentials proportional to electrode separation, d. differential amplifier means and e. mode switch means for selectively interconnecting said first and second storage means, said means for producing an output potential and said differential amplifier means to selectively produce a potential at the output of said differential amplifier means proportional to either i. the varying separation of said electrodes during the portion of a welding cycle when the workpiece expands, ii. the varying separation of said electrodes during the entire weld cycle or iii. the varying separation of said electrodes between the point of maximum expansion and the end of the welding cycle.
Claim 2
Dependent Claim
177 words
A weld monitor system for tracking the separation between a pair of welder electrodes, at least one of which is movable, a workpiece being positioned therebetween, the expansion, melting and solidification of the workpiece during a weld cycle causing variations in electrode separation, comprising; a. means for producing an output potential proportional to electrode separation, b. analog recorder means for recording said potential proportional to electrode separation, c. first and second storage means for storing potentials proportional to electrode separation, d. differential amplifier means and e. mode switch means for selectively interconnecting said first and second storage means, said means for producing an output potential and said differential amplifier means to selectively produce a potential at the output of said differential amplifier means proportional to either i. the varying separation of said electrodes during the portion of a welding cycle when the workpiece expands, ii. the varying separation of said electrodes during the entire weld cycle or iii. the varying separation of said electrodes between the point of maximum expansion and the end of the welding cycle.
Claim 3
Dependent Claim
94 words
The weld monitor of claim 1 further comprising; a digital voltmeter with recording means coupled to the differential amplifier and switch means for energizing said recording means at the end of a welding cycle, whereby there is recorded a potential proportional to either, the difference between electrode separation at the null point and at the maximum expansion point, the difference between electrode separation at the null point and at the end of the welding cycle or the difference between electrode separation at the maximum expansion point and at the end of the welding cycle.
Claim 4
Dependent Claim
45 words
The weld monitor of claim 2 further comprising, digital pulse counter means, voltage sensor means for indicating when the output from said differential amplifier reaches a predetermined potential and switch means responsive to said indication from said voltage sensor means for disabling said counter means.
Claim 5
Dependent Claim
59 words
The weld monitor of claim 3 further including a zero voltage circuit for indicating when the separation between the electrodes returns to the initial position assumed at the beginning of a weld cycle and switch means responsive to the output of the zero voltage circuit for disabling the counter means when the electrode separation returns to the initial position.
Claim 6
Dependent Claim
96 words
The weld monitor of claim 1 wherein said mode switch means comprises first and second movable contacts coupled to first and second inputs of said differential amplifier means, a first pair of fixed contacts coupled respectively to the first and second storage means, a second pair of fixed contacts coupled respectively to said second storage means and to the output of said means for producing a potential proportional to electrode separation and a third pair of fixed contacts coupled respectively to said first storage means and said output of the means for producing a proportional potential.
Claim 7
Dependent Claim
71 words
The weld monitor of claim 5 wherein said first and second storage means Comprise respectively first and second capacitors, said capacitors being coupled to the output of said means for producing a potential proportional to electrode separation through a diode, further including switch means for charging said second capacitor at the beginning of a weld cycle and subsequently blocking the further charging thereof during the remaining portion of the weld cycle.
Claim 8
Dependent Claim
21 words
The weld monitor of claim 6 wherein said means for producing a potential proportional to electrode separation comprises a differential transformer.
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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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |