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US3866004A Expired / Lapsed US ⏱️ 0.0 years remaining

Safety control device with obstruction feeler and switch assembly

Assignee: FL Jacobs Co
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Filing: 1973-07-05
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Granted: 1975-02-11
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Expires: 1993-07-05
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Abstract

Abstract The device is fixedly applied in any convenient way to an impact type machine, such as a riveter. This is powered hydraulically or otherwise for its impact stroke through and under the sole and direct control of the electrical circuitry of the device, to the exclusion of any other direct application of power to the machine. The latter has a pivoted sensor control arm operated for a vertical protective swing by foot switchcontrolled electrical solenoid means of said circuitry, the physical mounting of said sensor being such that it cannot complete its protective operation, in a limited space alotted, in the event of a significant obstruction in said space, viz., a finger or hand of an operator present in this danger area. For this purpose, the sensor arm has means to trip a microswitch of the circuitry only upon completing a full, solenoid-operated protective swing, whereupon the microswitch completes an electrical circuit through its power relay, the latter operating, for example, a solenoidtype valve controlling application of hydraulic power to the impact machine. If such full swing is obsructed, the microswitch is not operated, the power relay sub-circuit remains open, and an impact machine operation cannot take place. A signal lamp is wired to a normally closed contact of the microswitch to be instantaneously and momentarily energized as the microswitch is solenoid-operated to make its normal power relay engaging contact; and as this occurs the lamp extinguishes and remains unlit until another foot switch cycle is inaugurated. Otherwise, as in the case of obstruction of the full sensor member stroke, the microswitch remains as normally closed in the absence of its mechanical opening by the safety sensor arm and the signal lamp remains lit to call attention to the condition. The usual foot control switch of the impact machine is wired into the circuitry of the device between a terminal of an electrical power supply and the several parallel microswitch and power relay, microswitch-operating solenoid and auxiliary or accessory subcircuits of the present control circuitry, so that even with the foot switch closed an energizing voltage for the impact machine is applied to the latter only when the microswitch of the device completes the power relay sub-circuit.

Inventors

  • 👤 Norbert Joseph Nawrocki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 16:07
CPC Classifications
F; F16; F16P; F16P3/00; F16P3/02; F16P3/04

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 271 words
An impact or related type machine comprising a reciprocally movable tool part and an electrical operating circuit including a normally opened first switch and a power relay unit in series with said first switch, said power relay unit when energized effective to initiate movement of said tool part, a second switch interposed in said electrical operating circuit between said first switch and said power relay unit, said second switch having first and second positions, said second switch when in said first position opening said operating circuit between said first switch and said power relay unit, a safety control device governing operation of said electrical operating circuit comprising an elongated control arm pivotally mounted for a motion in which an end portion thereof may fully traverse a danger zone in proximity to the path of reciprocation of said tool part and prior to the reciprocation of said tool part, unless interrupted by a zone obstruction, said control device having an electrical safety circuit interposed in said operating circuit between said first and second switches parallel to said power relay unit, said electrical safety circuit being responsive to a signal initiated upon the closing of said first switch, said safety circuit including electrically responsive means connected to said control arm and when energized upon the closing of said first switch effective to swing said control arm through said danger zone unless the movement thereof is obstructed, said control arm after movement through said danger zone being effective to move said second switch to its second position thereby permitting current to flow through said power relay unit to initiate movement of said tool part.
Claim 2
Dependent Claim 271 words
An impact or related type machine comprising a reciprocally movable tool part and an electrical operating circuit including a normally opened first switch and a power relay unit in series with said first switch, said power relay unit when energized effective to initiate movement of said tool part, a second switch interposed in said electrical operating circuit between said first switch and said power relay unit, said second switch having first and second positions, said second switch when in said first position opening said operating circuit between said first switch and said power relay unit, a safety control device governing operation of said electrical operating circuit comprising an elongated control arm pivotally mounted for a motion in which an end portion thereof may fully traverse a danger zone in proximity to the path of reciprocation of said tool part and prior to the reciprocation of said tool part, unless interrupted by a zone obstruction, said control device having an electrical safety circuit interposed in said operating circuit between said first and second switches parallel to said power relay unit, said electrical safety circuit being responsive to a signal initiated upon the closing of said first switch, said safety circuit including electrically responsive means connected to said control arm and when energized upon the closing of said first switch effective to swing said control arm through said danger zone unless the movement thereof is obstructed, said control arm after movement through said danger zone being effective to move said second switch to its second position thereby permitting current to flow through said power relay unit to initiate movement of said tool part.
Claim 3
Dependent Claim 65 words
The machine defined in claim 1 wherein an electrically energizable signaling unit is interposed in said electrical operating circuit parallel to said power relay unit, with said second switch when in said first position permitting said signaling unit to be energized upon closing of said first switch, said signaling unit remaining energized until said relay unit is energized or until said first switch is opened.
Claim 4
Dependent Claim 19 words
The machine defined in claim 2 wherein said electrically energizable signaling unit is in the form of a light.
Claim 5
Dependent Claim 13 words
The machine defined in claim 1 wherein said first switch is manually operable.
Claim 6
Dependent Claim 21 words
The machine defined in claim 1 wherein said first switch is in the form of a manually operable foot type switch.
Claim 7
Dependent Claim 18 words
The machine defined in claim 1 wherein said power relay unit is in the form of a solenoid.
Claim 8
Dependent Claim 18 words
The machine defined in claim 1 wherein said electrically responsive means is in the form of a solenoid.
Claim 9
Dependent Claim 37 words
The machine defined in claim 1 wherein a return spring is interposed in said control device engageable with said control arm for biasing said control arm towards an inoperative position when said electrically responsive means is de-energized.
Claim 10
Dependent Claim 29 words
The machine defined in claim 1 wherein said control arm consists of two elongated parts adjustably secured together to permit the length of the control arm to be varied.
Claim 11
Dependent Claim 35 words
The machine defined in claim 1 wherein said end portion of said control arm has a ring-like member formed thereon through which the tool part moves after said control arm has traversed the danger zone.

References Cited (Backward Citations)

US3129799A Cited
US3315049A Cited
US3487182A Cited
US3554067A Cited
US3818238A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-02-10 1978-08-12 1979-02-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-02-10 1982-08-12 1983-02-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-02-10 1986-08-12 1987-02-11 $7700.00 Window Closed / Lapsed

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