US4131052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drum cam with anti hang-fire feature
Assignee: United States Department of the Army
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Filing: 1977-07-05
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Granted: 1978-12-26
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Expires: 1997-07-05
Abstract
Abstract A drum cam for reciprocating the operating group of an externally powered apon, wherein hang-fire is prevented by transferring the cam follower to a separate cam path when the group is in in-battery position, and the follower dwells until a chambered round has fired before permitting the operating group to recoil.
Inventors
- 👤 Fred J. Skahill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:29
CPC Classifications
F; F41; F41A; F41A7/00; F41A7/08; F41A7/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
A drum cam with anti hang-fire feature, in combination with the operating group of an externally powered automatic weapon, said cam comprising: a drum having a first diagonal groove for moving said operating group forward to in-battery position when a cam follower on said group is positioned in said first groove and said drum is rotating, said drum having a second diagonal groove for moving said operating group rearward to recoil position when a cam follower on said group is positioned in said second groove and said drum is rotating, and means responsive to the recoil of said operating group after firing of a cartridge for moving said cam follower into said second groove.
Claim 2
Dependent Claim
114 words
A drum cam with anti hang-fire feature, in combination with the operating group of an externally powered automatic weapon, said cam comprising: a drum having a first diagonal groove for moving said operating group forward to in-battery position when a cam follower on said group is positioned in said first groove and said drum is rotating, said drum having a second diagonal groove for moving said operating group rearward to recoil position when a cam follower on said group is positioned in said second groove and said drum is rotating, and means responsive to the recoil of said operating group after firing of a cartridge for moving said cam follower into said second groove.
Claim 3
Dependent Claim
105 words
A drum cam in combination with the operating group of an externally powered weapon as set forth in claim 1, said means comprising a depressible cam follower on said operating group, said drum having a circumferential groove, said first diagonal groove being engageable with and terminating in said circumferential groove, said cam follower being responsive to said circumferential groove when said operating group is in forward in-battery position, said circumferential groove having an inclined rear wall whereby recoil from a fired cartridge moves said operating group sufficienty rearwardly to move said cam follower up said ramp and rearwardly into engagement with said second diagonal groove.
Claim 4
Dependent Claim
59 words
A drum cam in combination with the operating group of an externally powered weapon as set forth in claim 2, said depressible cam follower having a spring therebehind to resiliently urge said follower into said grooves and permit depression thereof as said follower is urged up said ramp upon recoil of said operating group when said cartridge is fired.
Claim 5
Dependent Claim
39 words
A drum cam in combination with the operating group of an externally powered weapon as set forth in claim 1 wherein said first diagonal groove spirals forwardly in a direction opposite to the direction of rotation of said drum.
Claim 6
Dependent Claim
37 words
A drum cam in combination with the operating group of an externally powered weapon as in claim 1 wherein said second diagonal groove spirals forwardly in the same direction as the direction of rotation of said drum.
Claim 7
Dependent Claim
54 words
A drum cam in combination with the operating group of an externally powered weapon as in claim 1 wherein in operation the operating group moves forwardly, dwells in in-battery position until a cartridge firing recoils it rearwardly, and said group then moves rearwardly to recoil position while said drum continuously rotates in one direction.
References Cited (Backward Citations)
US4062266A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-25 | 1982-06-26 | 1982-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-25 | 1986-06-26 | 1986-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-25 | 1990-06-26 | 1990-12-26 | $7700.00 | Window Closed / Lapsed |