Patent US3764213A successfully refreshed from Google Patents.
US3596718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Torque control system
Assignee: Gardner Denver Inc
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Filing: 1969-07-02
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Granted: 1971-08-03
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Expires: 1989-07-02
Abstract
Abstract A control system for a torque producing power tool such as a nutsetter, screwdriver, or the like. The control system includes an electromechanical transducer which operates on the principle of a linear variable differential transformer. The transducer, in part, comprises the final drive spindle of the tool and is thereby in close proximity to the fastener being tightened. An electrical signal is produced by the transducer which is proportional to the torsional motive force applied to the drive spindle. The control system includes switching devices operable in response to a predetermined signal from the transducer to shut off the power supply to the tool and actuate various system condition indicators.
Inventors
- 👤 Charles Dennis Fish
- 👤 Ronald B Schildt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:43
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/14; B25B23/145; B25B23/1456
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
A control system for a torque producing tool, said tool comprising: motor means operable to produce a torsional motive force; drive means operable to be driven by said motor means to transmit said torsional motive force to a workpiece; supply means operable to be in communication with said motor means for delivering motive energy to operate said motor means; means operable to shut off said supply of motive energy to said motor means; said control system comprising; signal producing means interposed in said drive means between said motor means and said workpiece operable to produce an electrical signal proportional to the torsional motive force imposed on said drive means by said motor means; and, control means including a control circuit operable to receive said electrical signal from said signal producing means and in response to a predetermined electrical signal magnitude actuate said shutoff means to shut off the supply of motive energy to said motor means.
Claim 2
Dependent Claim
156 words
A control system for a torque producing tool, said tool comprising: motor means operable to produce a torsional motive force; drive means operable to be driven by said motor means to transmit said torsional motive force to a workpiece; supply means operable to be in communication with said motor means for delivering motive energy to operate said motor means; means operable to shut off said supply of motive energy to said motor means; said control system comprising; signal producing means interposed in said drive means between said motor means and said workpiece operable to produce an electrical signal proportional to the torsional motive force imposed on said drive means by said motor means; and, control means including a control circuit operable to receive said electrical signal from said signal producing means and in response to a predetermined electrical signal magnitude actuate said shutoff means to shut off the supply of motive energy to said motor means.
Claim 3
Dependent Claim
56 words
The invention set forth in claim 1 wherein: said control circuit is operable in response to receiving a first predetermined signal magnitude to actuate said shutoff means to shut off the supply of motive energy to said motor means and said control circuit includes first indicator means operable to indicate the actuation of said shutoff means.
Claim 4
Dependent Claim
40 words
The invention set forth in claim 2 wherein: said control circuit includes second indicator means operable in response to a second predetermined signal magnitude to indicate a torsional motive force exceeding the torsional motive force producing said first signal magnitude.
Claim 5
Dependent Claim
26 words
The invention set forth in claim 1 together with: recording means operable to record the magnitude of said electrical signal produced by said signal producing means.
Claim 6
Dependent Claim
26 words
The invention set forth in claim 1 wherein: said signal producing means comprises an element of said drive means between said motor means and said workpieces.
Claim 7
Dependent Claim
25 words
The invention set forth in claim 5 wherein: said signal producing means comprises the drive element of said tool which is engaged with said workpiece.
Claim 8
Dependent Claim
41 words
The invention set forth in claim 1 wherein: said signal producing means comprises an electromechanical transducer operable in response to a torsional motive force imposed on said drive means to produce an electrical signal having a magnitude proportional to said force.
Claim 9
Dependent Claim
16 words
The invention as set forth in claim 7 wherein: said electromechanical transducer comprises a differential transformer.
Claim 10
Dependent Claim
78 words
The invention as set forth in claim 1 wherein: said motor means is pressure fluid operated and includes a motor inlet passage, said energy supply means comprises a source of pressure fluid, said shutoff means comprises valve means interposed between said motor means and said supply means and operable in response to a predetermined electrical signal from said control means to shut off said supply of pressure fluid to said motor means and vent said motor inlet passage.
References Cited (Backward Citations)
US2867117A
Cited
US3276250A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |