US3769578A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Guard electrode apparatus for boom of insulated aerial device
Assignee: PITMAN MANUFACTURING COMPANY Inc (PITMAN) A CORP OF
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Filing: 1972-04-13
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Granted: 1973-10-30
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Expires: 1992-04-13
Abstract
Abstract Apparatus for measuring leakage current passing through the insulative section of the boom of an aerial device for lifting workmen to an elevated height wherein is provided a conductive element on the outer surface of the insulative section for collecting leakage current passing therethrough, and a grounded conductive shield disposed in electrically insulated, overlying relationship to the conductive element to prevent extraneous ambient electrical currents from reaching the conductive element and being measured.
Inventors
- 👤 J Staley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:41
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/025
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
171 words
Apparatus for monitoring current leakage through the electrically insulative section of a boom of an aerial device, comprising: a conductive band disposed transversely around the outside surface of an insulative section of said boom for collecting leakage current passing through said section; detecting means electrically connected with said band for measuring said boom leakage current; at least one guard conductor disposed in spaced, surrounding, covering relationship to said band, said guard conductor being wider than said conductive band and extending beyond the opposed side marginal edges thereof; an insulative support carried by the boom in supporting relationship to said guard conductor to maintain the latter electrically insulated from said band, said support including a layer of synthetic resinous material disposed between the guard conductor and the band and at least partially incapsulating the guard conductor to protect the latter from mechanical abrasion and damage by external objects; and ground means connected to said guard conductor for electrically grounding the latter whereby said detecting means measures substantially only said boom leakage current.
Claim 2
Dependent Claim
171 words
Apparatus for monitoring current leakage through the electrically insulative section of a boom of an aerial device, comprising: a conductive band disposed transversely around the outside surface of an insulative section of said boom for collecting leakage current passing through said section; detecting means electrically connected with said band for measuring said boom leakage current; at least one guard conductor disposed in spaced, surrounding, covering relationship to said band, said guard conductor being wider than said conductive band and extending beyond the opposed side marginal edges thereof; an insulative support carried by the boom in supporting relationship to said guard conductor to maintain the latter electrically insulated from said band, said support including a layer of synthetic resinous material disposed between the guard conductor and the band and at least partially incapsulating the guard conductor to protect the latter from mechanical abrasion and damage by external objects; and ground means connected to said guard conductor for electrically grounding the latter whereby said detecting means measures substantially only said boom leakage current.
Claim 3
Dependent Claim
55 words
Apparatus as set forth in claim 1, wherein said boom is hollow, and further includes a second conductive band disposed transversely about the inside surface of said boom for collecting leakage current passing through said boom, said detecting means being electrically connected with said first and second bands respectively for measuring said boom leakage current.
Claim 4
Dependent Claim
36 words
Apparatus as set forth in claim 1, wherein said device is mounted on an electrically grounded vehicle body, said ground means electrically connecting said guard conductor with the vehicle body whereby to ground said guard means.
Claim 5
Dependent Claim
32 words
Apparatus as set forth in claim 1, wherein said support layer has a segment between the guard conductor and boom of sufficient thickness to maintain the distance therebetween at about five-sixteenths inch.
Claim 6
Dependent Claim
33 words
Apparatus as set forth in claim 1, wherein said support layer has a groove on the inner surface thereof which is configured and arranged such that the layer does not contact said band.
Claim 7
Dependent Claim
50 words
Apparatus as set forth in claim 1, wherein said guard conductor partially incapsulated by synthetic resinous material is divided into two U-shaped sections, there being means for releasably, mechanically and electrically interconnecting the conductors of said two sections and for securing the latter on the outside surface of said boom.
Claim 8
Dependent Claim
172 words
Guard apparatus for a conductive band disposed transversely around the outside surface of the insulative section of a boom of an aerial device to collect leakage current passing through said section, said apparatus including: a guard conductor disposed externally of said band in surrounding, covering, electrically insulated relationship thereto, said guard conductor being wider than said band and extending past the opposed side marginal edges thereof and being operable to collect extraneous ambient electrical currents not passing through said boom to prevent tHe same from reaching said band; an insulative support carried by the boom in supporting relationship to said guard conductor to maintain the latter electrically insulated from said band, said support including a layer of synthetic resinous material disposed between the guard conductor and the band and at least partially incapsulating the guard conductor to protect the latter from mechanical abrasion and damage by external objects; and ground means connected to said guard conductor for electrically grounding the latter whereby said detecting means measures substantially only said boom leakage current.
Claim 9
Dependent Claim
172 words
Guard apparatus for a conductive band disposed transversely around the outside surface of the insulative section of a boom of an aerial device to collect leakage current passing through said section, said apparatus including: a guard conductor disposed externally of said band in surrounding, covering, electrically insulated relationship thereto, said guard conductor being wider than said band and extending past the opposed side marginal edges thereof and being operable to collect extraneous ambient electrical currents not passing through said boom to prevent tHe same from reaching said band; an insulative support carried by the boom in supporting relationship to said guard conductor to maintain the latter electrically insulated from said band, said support including a layer of synthetic resinous material disposed between the guard conductor and the band and at least partially incapsulating the guard conductor to protect the latter from mechanical abrasion and damage by external objects; and ground means connected to said guard conductor for electrically grounding the latter whereby said detecting means measures substantially only said boom leakage current.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |