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US 4,523,379 AGranted
Knife with retractable sheath
AssigneeTekna
InventorsRalph F. Osterhout, John D. Burr, Eric R. Larson
Life of this patent
Estimating the term…
Abstract
A safety utility knife includes a handle, a blade fixed to the forward end of the handle, and a retractable sheath which is received within the handle. A mechanism is provided for automatically retracting the sheath within the handle by depressing a single button at the rear of the handle.
Claims19
An implement comprising:
- a handle having a hollow interior with an opening at one end;
- a tool fixedly attached to the handle at the opening;
- a sheath slidably mounted within the hollow interior of the handle to reciprocate between an extended position where said sheath covers the tool and a retracted position where the tool is exposed;
- a compressible elastic member disposed between the sheath and the tool so that said elastic member is relaxed when the sheath is fully retracted and compressed when the sheath is extended;
- and
- means for releasably securing the sheath in its fully extended position, whereby when the sheath is released, the elastic member will extend and impel the sheath into the interior of the handle.
3 more elements
A safety knife comprising:
- an elongate handle having a hollow interior with openings at each end;
- a knife blade fixedly secured in one opening of the handle by at least one post, the periphery of the blade being spaced apart from the interior wall of the opening;
- a protective sheath having four side walls and being open at either end, said sheath having slots in a pair of opposite side walls, which slots are received on the post to allow the sheath to slide between an extended position where the knife blade is fully covered and a retracted position where the sheath is fully received within the handle;
- and
- means for retracting the sheath from its fully extended position to its fully retracted position.
2 more elements
Dependencies are inferred from the claim text.