Patent US3917941A successfully refreshed from Google Patents.
US3917941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lamp guard
Assignee: Woodhead Industries LLC
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Filing: 1974-10-17
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Granted: 1975-11-04
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Expires: 1994-10-17
Abstract
Abstract A lamp guard for protecting the lamp bulbs of hand lamps, trouble lamps, stringlights and the like is disclosed, wherein two flexible annular enclosure members, having tapered sides and molded from a transparent or translucent material, such as a synthetic polymer, are locked together by interengaging threads on the two members, and prevented from pulling apart by an annular retainer. An annular groove on one member receives an annular rib on the other, thereby forming a ''''tongue and groove'''' type of connection, wherein threads on one face of the rib engage similar threads on the adjacent wall of the groove, and the depths of the threads are greater than the clearance between the rib and the internal walls of the groove, whereby when a compressive force is applied to a side of the guard in the area of the connection between the two enclosure members, which would tend to pull the members apart at a point substantially 90* from the point where the force is applied and crush the guard, the threads of the tongue and groove construction together with the annular retainer will hold them together and prevent crushing.
Inventors
- 👤 Tony Trevithick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:34
CPC Classifications
F; F21; F21V; F21V15/00; F21V15/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
150 words
A lamp guard comprising, a. a first enclosure member formed of a flexible material adapted to have a lamp mounted therein, and having a circular inner end portion, b. a second enclosure member also formed of a flexible material and having a circular inner end portion cooperating with said first enclosure member to form the completed guard, c. the outer end of at least one of said members having a smaller diameter than the inner end thereof, d. an axially extending annular groove around one of said members adjacent the inner end thereof having inner and outer walls, e. an axially extending annular rib around the other of said members having inner and outer faces thereon and received within said annular groove of said one member, and f. means removably securing said members together including interengaging threads on a wall of said groove and on a face of said rib.
Claim 2
Dependent Claim
150 words
A lamp guard comprising, a. a first enclosure member formed of a flexible material adapted to have a lamp mounted therein, and having a circular inner end portion, b. a second enclosure member also formed of a flexible material and having a circular inner end portion cooperating with said first enclosure member to form the completed guard, c. the outer end of at least one of said members having a smaller diameter than the inner end thereof, d. an axially extending annular groove around one of said members adjacent the inner end thereof having inner and outer walls, e. an axially extending annular rib around the other of said members having inner and outer faces thereon and received within said annular groove of said one member, and f. means removably securing said members together including interengaging threads on a wall of said groove and on a face of said rib.
Claim 3
Dependent Claim
32 words
A lamp guard, as defined in claim 1, wherein the threads in said groove are on the inner wall thereof and the threads on said rib are on the inner face thereof.
Claim 4
Dependent Claim
23 words
A lamp guard, as defined in claim 1, wherein said enclosure members are provided with a plurality of axially extending circumferentially spaced openings.
Claim 5
Dependent Claim
25 words
A lamp guard, as defined in claim 1, wherein the axial length of said rib is substantially equal to the axial depth of said groove.
Claim 6
Dependent Claim
56 words
A lamp guard, as defined in claim 1, wherein the depth of said interengaging threads is greater than the clearance provided between the faces of said rib and the walls of said groove, thereby to prevent separation of said members when pressure is applied to the guard causing flexing thereof in the area of said threads.
Claim 7
Dependent Claim
171 words
A lamp guard comprising, a. a first annular and flexible enclosure member adapted to have a lamp mounted therein, and having a circular inner end portion, b. a second annular and flexible enclosure member also having a circular inner end portion cooperating with said first enclosure member to form the completed guard, c. both of said enclosure members having tapered surfaces with the inner ends thereof having a greater diameter than the outer ends thereof, d. an axially extending annular groove having inner and outer walls around one of said members adjacent the inner end thereof, e. an axially extending annular rib around the other of said members having inner and outer faces thereon and received within said annular groove of said one member, and f. interengaging threads on a wall of said groove and a face of said rib to removably secure said members together, g. the depth of said interengaging threads being greater than the clearance between the face of said rib and the adjacent wall of said groove.
Claim 8
Dependent Claim
171 words
A lamp guard comprising, a. a first annular and flexible enclosure member adapted to have a lamp mounted therein, and having a circular inner end portion, b. a second annular and flexible enclosure member also having a circular inner end portion cooperating with said first enclosure member to form the completed guard, c. both of said enclosure members having tapered surfaces with the inner ends thereof having a greater diameter than the outer ends thereof, d. an axially extending annular groove having inner and outer walls around one of said members adjacent the inner end thereof, e. an axially extending annular rib around the other of said members having inner and outer faces thereon and received within said annular groove of said one member, and f. interengaging threads on a wall of said groove and a face of said rib to removably secure said members together, g. the depth of said interengaging threads being greater than the clearance between the face of said rib and the adjacent wall of said groove.
Claim 9
Dependent Claim
25 words
A lamp guard, as defined in claim 6, wherein said annular groove is on said first member, and said rib is on said second member.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |