US3892146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric control for an electric motor operated nut fastening tool
Assignee: Shibaura Mechatronics Corp
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Filing: 1974-08-28
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Granted: 1975-07-01
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Expires: 1994-08-28
Abstract
Abstract An electric motor operated nut fastening tool is disclosed which is adapted for use with a removably mounted nut setting adaptor. An electric control circuit is provided for running the motor forward to tighten the nut. The nut is driven until the motor armature current increases to a predetermined amplitude, thereby causing the control circuit to reverse the motor and release the nut from the adaptor.
Inventors
- 👤 Hiroshi Yasoshima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:09
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/0078; B25B21/00; B25B23/14; B25B23/147; H; H02; H02P; H02P25/00; H02P25/02; H02P25/10; H02P25/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
173 words
A nut fastening tool adapted for use with a nut setting adaptor, comprising: a body portion enclosing said nut fastening tool, said body portion adapted to have said nut setting adaptor removably mounted thereon, a reversible electric motor for driving said nut setting adaptor mounted in said body portion, a manual switch for energizing said motor; and, an electric control circuit coupled to said motor for controlling the operation thereof, said control circuit including a forward driving circuit and a reverse driving circuit, at least a pair of thyristors, one of which is used for switching said forward driving circuit on and off, and the other of which is used for switching said reverse driving circuit on and off, said control circuit further including means responsive to a predetermined forward driving current flowing through said motor for controlling said thyristors to switch said forward driving circuit off and said reverse driving circuit on; whereby a nut is tightened by said fastening tool and then automatically released from nut setting adaptor when completely tightened.
Claim 2
Dependent Claim
173 words
A nut fastening tool adapted for use with a nut setting adaptor, comprising: a body portion enclosing said nut fastening tool, said body portion adapted to have said nut setting adaptor removably mounted thereon, a reversible electric motor for driving said nut setting adaptor mounted in said body portion, a manual switch for energizing said motor; and, an electric control circuit coupled to said motor for controlling the operation thereof, said control circuit including a forward driving circuit and a reverse driving circuit, at least a pair of thyristors, one of which is used for switching said forward driving circuit on and off, and the other of which is used for switching said reverse driving circuit on and off, said control circuit further including means responsive to a predetermined forward driving current flowing through said motor for controlling said thyristors to switch said forward driving circuit off and said reverse driving circuit on; whereby a nut is tightened by said fastening tool and then automatically released from nut setting adaptor when completely tightened.
Claim 3
Dependent Claim
66 words
A device according to claim 1, wherein said electric control circuit further includes: a UJT oscillator circuit adapted to operate in synchronism with the frequency of an A.C. voltage supply, and said UJT oscillator circuit coupled to one of said thyristors for applying gating signals thereto, said ocsillator terminating its output in response to a predetermined peak value of the forward driving current of said motor.
Claim 4
Dependent Claim
45 words
A device according to claim 2, in which said control circuit further includes: an auxiliary thyristor which turns on in response to a predetermined voltage of said forward driving current of said motor and keeps said UJT oscillator off until said manual switch is opened.
Claim 5
Dependent Claim
61 words
A device according to claim 3, in which said control circuit further includes: means for detecting the forward driving current level of said motor, means for generating a reference current; and, means for comparing the detected forward driving current with said reference current to turn on said suxiliary axuiliary when said forward driving current becomes substantially equal to said reference current.
Claim 6
Dependent Claim
40 words
A device according to claim 3, in which said control circuit further includes: a second UJT relaxation oscillator which starts its oscillation in response to the turning on of said auxiliary thyristor thereby to effect reverse rotation of said motor.
Claim 7
Dependent Claim
110 words
A device according to claim 1, wherein said nut setting adaptor includes: a nut socket for receiving a nut therein for fastening, a tubular member removably mountable on one end of said tool body and fixable thereto so as to surround said nut socket, said tubular member being provided with a pair of wing members radially extending from opposite edge portions of said tubular member, said wing members being adapted to take a position engaged with adjacent bolt-nut assemblies during the tightening of a nut located between said bolt-nut assemblies, whereby said nut setting adaptor bears against a reaction force occuring upon the tightening of said nut to be fastened.
Claim 8
Dependent Claim
57 words
A device according to claim 4, wherein said current reference generating means includes: a potentiometer coupled to a constant D.C. voltage supply, whereby a variable current reference is obtained from said potentiometer for adjusting the gating of one of said pair of thyristors to turn one of said thyristors off at a desired level of motor torque.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |