Patent US4266221A successfully refreshed from Google Patents.
US4266221A
Expired / Lapsed
US
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Personnel alarm circuit for industrial machinery
Assignee: Individual
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Filing: 1979-09-20
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Granted: 1981-05-05
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Expires: 1999-09-20
Abstract
Abstract An alarm circuit is interlocked with the start circuit of power driven industrial machinery such as a coal tipple so that before the machinery can be started, an alarm must be energized for a predetermined time to alert personnel that the machine is about to start. In the event that the machinery is not started within a predetermined time after termination of the alarm, or in the event that the alarm has not actually sounded, the whole cycle must be repeated.
Inventors
- 👤 J. C. Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:00
CPC Classifications
F; F16; F16P; F16P3/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
130 words
A safety circuit for use in connection with power driven industrial machinery comprising: a start circuit for the machinery; alarm means; means interlocked with said start circuit disabling operation thereof until said alarm means has been energized for a predetermined time; means responsive to actual operation of said alarm, interlocked with said start circuit disabling operation thereof until said alarm means has actually operated for a predetermined time; manual means for energizing said alarm; means in circuit with said alarm for terminating said alarm after a predetermined time; means responsive to termination of said alarm for enabling said start circuit; and means for disabling said start circuit in the event that the equipment with which it is associated does not start within a predetermined time following termination of said alarm.
Claim 2
Dependent Claim
130 words
A safety circuit for use in connection with power driven industrial machinery comprising: a start circuit for the machinery; alarm means; means interlocked with said start circuit disabling operation thereof until said alarm means has been energized for a predetermined time; means responsive to actual operation of said alarm, interlocked with said start circuit disabling operation thereof until said alarm means has actually operated for a predetermined time; manual means for energizing said alarm; means in circuit with said alarm for terminating said alarm after a predetermined time; means responsive to termination of said alarm for enabling said start circuit; and means for disabling said start circuit in the event that the equipment with which it is associated does not start within a predetermined time following termination of said alarm.
Claim 3
Dependent Claim
35 words
A safety circuit as defined by claim 1 and including fail safe means connected to said alarm means and responsive to open circuit conditions in said alarm means for preventing enabling of said start circuit.
Claim 4
Dependent Claim
24 words
A safety circuit as defined by claim 1 in which said means responsive to actual operation of said alarm is a sound powered relay.
References Cited (Backward Citations)
US3631447A
Cited
US4110742A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-04 | 1984-11-03 | 1985-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-04 | 1988-11-03 | 1989-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-04 | 1992-11-03 | 1993-05-05 | $7700.00 | Window Closed / Lapsed |