US4302877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single spring double lockblade folding knife
Assignee: WR Case and Sons Cutlery Co
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Filing: 1980-05-12
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Granted: 1981-12-01
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Expires: 2000-05-12
Abstract
Abstract A foldable knife is provided having two lock blades each of which or both of which simultaneously may be locked in their open position against movement in either direction about their respective pivots. A separate locking member and tumbler is provided for each blade but only a single spring is utilized to operate both locking members and urge them toward their locked position.
Inventors
- 👤 Thomas D. Hart
- 👤 David J. Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:58
CPC Classifications
B; B26; B26B; B26B1/00; B26B1/02; B26B1/04; B26B1/042
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
80 words
In a foldable knife having a handle and two blades pivoted to the handle for movement to and from open and closed positions, the improvement comprising: (a) a locking member for each of said blades mounted in tandem to said handle for movement to and from locked and unlocked positions; each of said members mounted on separate spaced-apart pivot means and (b) a single spring mounted in said handle for urging both of said locking members toward their locked position.
Claim 2
Dependent Claim
80 words
In a foldable knife having a handle and two blades pivoted to the handle for movement to and from open and closed positions, the improvement comprising: (a) a locking member for each of said blades mounted in tandem to said handle for movement to and from locked and unlocked positions; each of said members mounted on separate spaced-apart pivot means and (b) a single spring mounted in said handle for urging both of said locking members toward their locked position.
Claim 3
Dependent Claim
48 words
The knife of claim 1, in which each of said locking members has a tumbler, and each of said tumblers in the closed position of its respective blade bearing against a portion of the blade for maintaining the blade in closed position under the force of said spring.
Claim 4
Dependent Claim
49 words
The knife of claim 2, in which each of said blades has a tumbler receiving notch, and each of said blades when in its open position receiving the tumbler of its respective locking member within its tumbler receiving notch to prevent movement of said blade relative to said handle.
Claim 5
Dependent Claim
45 words
The knife of claim 3, in which each of said locking members has a manually operable lock release for moving its respective tumbler out of its locking engagement with its respective notch upon manual operation of said lock release against the urging of said spring.
Claim 6
Dependent Claim
35 words
The knife of claim 4, in which each of said locking members is a lever pivoted in said handle, and in which said tumblers and said lock releases are integral portions of their respective levers.
Claim 7
Dependent Claim
57 words
The knife of claim 1, in which each of said locking members has a tumbler, each of said blades has a tumbler receiving notch, and each of said blades when in its open position receiving the tumbler of its respective locking member within its tumbler receiving notch to prevent movement of said blade relative to said handle.
Claim 8
Dependent Claim
45 words
The knife of claim 6, in which each of said locking members has a manually operable lock release for moving its respective tumbler out of its locking engagement with its respective notch upon manual operation of said lock release against the urging of said spring.
Claim 9
Dependent Claim
35 words
The knife of claim 7, in which each of said locking members is a lever pivoted in said handle, and in which said tumblers and said lock releases are integral portions of their respective levers.
Claim 10
Dependent Claim
39 words
The knife of any one of the preceding claims, in which said spring is elongated, said spring is pivoted adjacent its center in said handle, and each of the ends of said elongated spring bears against a locking member.
References Cited (Backward Citations)
US988068A
Cited
US1341153A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-30 | 1985-06-01 | 1985-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-30 | 1989-06-01 | 1989-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-30 | 1993-06-01 | 1993-12-01 | $7700.00 | Window Closed / Lapsed |