US3752367A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plunger assembly for hand-operated grease gun
Assignee: Individual
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Filing: 1972-06-26
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Granted: 1973-08-14
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Expires: 1992-06-26
Abstract
Abstract A plunger assembly for use in hand operated grease guns which have a cylindrical grease container with a rod extending axially therein and which are adapted for use with both bulk-filled and cartridge-packaged greases; said plunger assembly comprises a cylindrical sleeve with a bore therethrough carrying a sealing ring to provide a sliding, grease-tight seal with said rod, a guide assembly rigidly mounted on said sleeve which receives and secures an annular flexible sealing means with rearwardly extending sidewalls and a plunger cup slidably mounted on said rod which engages said sidewalls in operation to urge them outward by a pivotal flexing action to selectively provide a sliding, grease-tight fit around the outside of the plunger assembly.
Inventors
- 👤 E Sundholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:09
CPC Classifications
F; F04; F04B; F04B53/00; F04B53/14; F16; F16J; F16J1/00; F16J1/005; F16J1/006; F16J1/008; F16J15/00; F16J15/16; F16J15/32; F16J15/3204; F16J15/3208; F16N; F16N3/00; F16N3/10; F16N3/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
304 words
In a hand-operated grease gun of the type having a cylindRical grease container with a rod extending axially therein, said grease gun being adapted for use with both cartridge-packaged greases and bulk-filled greases, the plunger assembly therein which comprises: a. a cylindrical sleeve having a forward end and a rearward end and providing a bore therethrough for slidably receiving said rod; b. a sealing ring carried by said sleeve providing a greasetight seal with said rod; c. a guide assembly rigidly mounted on the forward end portion of said sleeve, said assembly comprising a base plate and a cover plate positioned in a face-to-face relationship and adapted to cooperatively receive and secure an annular flexible sealing means positioned therebetween when said plates are attached to each other, said cover plate having an opening centrally therethrough for receiving and securing said forward end portion of said sleeve, said base plate having an opening centrally therethrough concentric with said opening in said cover plate for slidably receiving said rod; d. engaging means for attaching said base plate and said cover plate in a face-to-face relationship; e. annular flexible sealing means cooperatively received and secured between said plates when attached, said annular sealing means having an annular flexible portion extending rearwardly along the outer edge of said guide assembly; f. a plunger cup slidably mounted on said sleeve, said cup having a base whose transverse dimensions are substantially equal to the transverse dimensions of said cover plate and having outwardly bevelled and rearwardly extending sidewalls concentric with said sleeve such that when said cup base is pushed into a close relationship without touching said cover plate, said sidewalls urge outwardly said rearwardly extending portions of said annular sealing means by a pivotal flexing action to provide a sliding, grease-tight fit around the outside of said plunger assembly.
Claim 2
Dependent Claim
304 words
In a hand-operated grease gun of the type having a cylindRical grease container with a rod extending axially therein, said grease gun being adapted for use with both cartridge-packaged greases and bulk-filled greases, the plunger assembly therein which comprises: a. a cylindrical sleeve having a forward end and a rearward end and providing a bore therethrough for slidably receiving said rod; b. a sealing ring carried by said sleeve providing a greasetight seal with said rod; c. a guide assembly rigidly mounted on the forward end portion of said sleeve, said assembly comprising a base plate and a cover plate positioned in a face-to-face relationship and adapted to cooperatively receive and secure an annular flexible sealing means positioned therebetween when said plates are attached to each other, said cover plate having an opening centrally therethrough for receiving and securing said forward end portion of said sleeve, said base plate having an opening centrally therethrough concentric with said opening in said cover plate for slidably receiving said rod; d. engaging means for attaching said base plate and said cover plate in a face-to-face relationship; e. annular flexible sealing means cooperatively received and secured between said plates when attached, said annular sealing means having an annular flexible portion extending rearwardly along the outer edge of said guide assembly; f. a plunger cup slidably mounted on said sleeve, said cup having a base whose transverse dimensions are substantially equal to the transverse dimensions of said cover plate and having outwardly bevelled and rearwardly extending sidewalls concentric with said sleeve such that when said cup base is pushed into a close relationship without touching said cover plate, said sidewalls urge outwardly said rearwardly extending portions of said annular sealing means by a pivotal flexing action to provide a sliding, grease-tight fit around the outside of said plunger assembly.
Claim 3
Dependent Claim
55 words
The plunger assembly of claim 1 wherein said cover plate has at least one indexing means attached thereto extending rearwardly from said cover plate with at least one slot in said plunger cup base designed to receive said indexing means, thereby preventing said plunger cup and said guide assembly from turning relative to each other.
Claim 4
Dependent Claim
59 words
The plunger assembly of claim 1 wherein said plunger cup sidewalls have at least one locking flange extending rearwardly from the top of said sidewalls, said locking flanges designed to cooperatively engage said grease container to demountably hold at rest said plunger cup so that it does not effectively touch said rearwardly extending portion of said annular sealing means.
Claim 5
Dependent Claim
80 words
The plunger assembly of claim 1 wherein said sealing ring is an O-ring positioned in an internal cylindrical space fashioned in the rearward end of said sleeve, said space having transverse dimensions substantially equal to the external dimensions of said O-ring and having a height dimension greater than the height dimension of said O-ring such that the adjacent outer wall of said sleeve can be crimped to securely hold said O-ring to provide a sliding, grease-tight fit with said rod.
Claim 6
Dependent Claim
19 words
The plunger assembly of claim 1 wherein said engaging means is a series of spot welds between said plates.
Claim 7
Dependent Claim
133 words
In a plunger assembly for use in a hand-operated grease gun which has a cylindrical grease container with a rod extending axially therein and which is adapted for use with both bulk-filled and cartridge-packaged greases, the plunger assembly which includes a cylindrical sleeve with a bore therethrough carrying a sealing ring to provide a sliding grease-tight seal with said rod, a guide assembly rigidly mounted on said sleeve which receives and secures an annular flexible sealing means with rearwardly extending sidewalls and a plunger cup slidably mounted on said rod which engages said sidewalls, the improvement which comprises an annular flexible sealing means whose rearwardly extending sidewalls are urged outwardly by said plunger cup by A pivotal flexing action to selectively provide a sliding, grease-tight fit around the outside of said plunger assembly.
Claim 8
Dependent Claim
133 words
In a plunger assembly for use in a hand-operated grease gun which has a cylindrical grease container with a rod extending axially therein and which is adapted for use with both bulk-filled and cartridge-packaged greases, the plunger assembly which includes a cylindrical sleeve with a bore therethrough carrying a sealing ring to provide a sliding grease-tight seal with said rod, a guide assembly rigidly mounted on said sleeve which receives and secures an annular flexible sealing means with rearwardly extending sidewalls and a plunger cup slidably mounted on said rod which engages said sidewalls, the improvement which comprises an annular flexible sealing means whose rearwardly extending sidewalls are urged outwardly by said plunger cup by A pivotal flexing action to selectively provide a sliding, grease-tight fit around the outside of said plunger assembly.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |