초록 ▼

A retractable knife includes an elongate handle and a blade holder slidingly mounted within the handle for sliding movements between a retracted position and an extended position. The blade holder is configured for receiving. A manually operable blade lock is formed on the holder and including a rel

A retractable knife includes an elongate handle and a blade holder slidingly mounted within the handle for sliding movements between a retracted position and an extended position. The blade holder is configured for receiving. A manually operable blade lock is formed on the holder and including a release member rotatably mounted on the blade holder. The release member having a first portion projecting beyond the handle and positioned to be actuated by a finger of a user while holding the handle. A second portion is movable with the first portion between a locking position in which the second portion is received with a notch of a blade and a releasing position in which the second position is removed from the blade notch to a position outside the notch of the blade. A spring normally rotates the release member to move the second portion to the locking position. Actuation of the release member by the finger of the user to overcome the spring moves the second portion to the releasing position and releases the blade.

대표청구항 ▼

1. Retractable knife comprising an elongate handle defining a handle axis; a release button mounted for movements along said handle axis; a blade holder slidingly mounted within said handle responsive to actuation of said release button for sliding movements along said handle between a retracted pos

1. Retractable knife comprising an elongate handle defining a handle axis; a release button mounted for movements along said handle axis; a blade holder slidingly mounted within said handle responsive to actuation of said release button for sliding movements along said handle between a retracted position and an extended position in which at least a portion of said blade holder extends beyond said handle and having an upper edge, receiving means within said blade holder for receiving at least a portion of a blade provided with one edge formed with a cutting edge and opposing edge formed with a notch; and a manually operable blade lock formed on said portion of said blade holder and comprising a release member rotatably mounted on said blade holder, said release member having a first portion on said blade holder and mounted to be actuated by movement of a finger of the same hand of a user holding said handle along a direction substantially parallel to said handle axis, and a second portion mounted on said first portion for movements with said first portion between a locking position in which said second portion is received within a notch of a blade and a releasing position in which said second portion is removed from the blade notch to a position beyond the notch of the blade, said release member being substantially in the form of a disc having an axis of rotation substantially normal to said handle axis and rotatably mounted on said blade holder for rotation about said release member axis of rotation, said first portion at least partially projecting above said upper edge of said blade holder to always be exposed for engagement by the user in both said blade locking and blade releasing positions when said release member is actuated while said blade holder is extended along said handle axis beyond said handle at a position spaced from said release button in the direction of the blade to be removed, and biasing means for normally moving said release member to move said second portion to said locking position, whereby actuation of said release member by the finger of the user to overcome said biasing means moves said second portion to said releasing position for releasing the blade so that it can be withdrawn from said receiving means. 2. Retractable knife as defined in claim 1, wherein said release member comprises a circular disc. 3. Retractable knife as defined in claim 2, wherein said first portion comprises an arc of said disc that projects beyond said upper edge of said blade holder. 4. Retractable knife as defined in claim 3, wherein said first portion is provided with gripping means for enhancing friction when gripped by a finger of a user seeking to rotate said disc against the action of said biasing means. 5. Retractable knife as defined in claim 4, wherein said gripping means comprises a non-smooth edge along said arc. 6. Retractable knife as defined in claim 1, wherein said second portion is fixedly mounted on said first portion. 7. Retractable knife as defined in claim 1, wherein said blade holder is received within a longitudinal space or gap within said handle with little clearance, facing surfaces of said blade holder and handle being polished to minimize sliding friction. 8. Retractable knife as defined in claim 7, further comprising a lubricant at said facing surfaces to reduce sliding friction. 9. Retractable knife as defined in claim 1, further comprising a blade holder lock on said blade holder having a gripping portion extending beyond said handle to be engageable by the thumb of a user and for selectively locking said blade holder against movements between said extended and retracted positions and releasing said blade holder for movement from one of said positions to the other. 10. A knife as defined in claim 1, wherein said handle has first and second handle portions, said handle portions being connected to each other in spaced relationships to form a space between said handle portions and a generally open periphery including a front aperture, a rear aperture, a top aperture and a bottom aperture; a utility blade; andsaid blade holder being configured to cover at least a portion of said utility blade, wherein said blade holder is telescopically movable relative to the handle through said front aperture between an extended position and a retracted position. 11. The knife of claim 10, further including a button configured to move the blade holder between the extended position and the retracted position, wherein said button extends through said top aperture. 12. The knife of claim 11, wherein said button is configured to move along said top aperture as said blade holder moves between said extended position and said retracted positions. 13. The knife of claim 10, wherein said handle includes an track formed on an internal surface thereof and said second handle portion include a corresponding track on an internal surface thereof parallel to said internal track on said first handle portion. 14. The knife of claim 13, wherein said blade holder includes at least one pin member configured to slide in said tracks as said blade holder moves between the extended and retracted positions. 15. The knife of claim 13, wherein said tracks include a front indent proximate to said front aperture and a rear indent proximate to said rear aperture. 16. The knife of claim 13, wherein said button is movable between an extended blade holder locking position and a retracted blade holder releasing position and wherein said button is normally biased in the extended locking position. 17. The knife of claim 13, wherein the button includes a protrusion member that interacts with said front indent to lock said blade holder in the extended position and said rear indent to lock the blade holder in the retracted position. 18. Retractable knife comprising an elongate handle; defining a handle axis: a release button mounted for movements along said handle axis; a blade holder slidingly mounted within said handle responsive to actuation of said release button for sliding movements relative to said handle between a retracted position and an extended position in which at least a portion of said blade holder extends beyond said handle and having an upper edge, receiving means within said blade holder for receiving at least a portion of a blade provided with one edge formed with a cutting edge and opposing edge formed with a notch; and a manually operable blade lock formed on said portion of said blade holder and comprising a release member rotatably mounted on said blade holder, said release member having a first portion on said blade holder and mounted to be actuated by movement of a finger of the same hand of a user holding said handle along a direction substantially parallel to said handle axis, and a second portion mounted on said first portion for movements with said first portion between a locking position in which said second portion is received within a notch of a blade and a releasing position in which said second portion is removed from the blade notch to a position beyond the notch of the blade, said release member being substantially in the form of a disc having an axis of rotation substantially normal to said handle axis and rotatably mounted on said blade holder for rotation about said release member axis of rotation, said first portion at least partially projecting above said upper edge of said blade holder to always be exposed for engagement by the user in both said blade locking and blade releasing positions when said release member is actuated while said blade holder is extended along said handle axis beyond said handle at a position spaced from said release button in the direction of the blade to be removed, and biasing means for normally moving said release member to move said second portion to said locking position, said blade holder being received within a longitudinal space or gap within said handle with little clearance, facing surfaces of said blade holder and handle being polished to minimize sliding friction, whereby actuation of said release member by the finger of the user to overcome said biasing means moves said second portion to said releasing position for releasing the blade so that it can be withdrawn from said receiving means. 19. Retractable knife as defined in claim 18, further comprising a lubricant at said facing surfaces to reduce sliding friction. 20. Retractable knife comprising an elongate handle; defining a handle axis: a release button mounted for movements along said handle axis; a blade holder slidingly mounted within said handle responsive to actuation of said release button for sliding movements relative to said handle between a retracted position and an extended position in which at least a portion of said blade holder extends beyond said handle and having an upper edge, receiving means within said blade holder for receiving at least a portion of a blade provided with one edge formed with a cutting edge and opposing edge formed with a notch; and a manually operable blade lock formed on said portion of said blade holder and comprising a release member on said blade holder, said release member having a first portion rotatably mounted on said blade holder and mounted to be actuated by movement of a finger of the same hand of a user holding said handle along a direction substantially parallel to said handle axis, and a second portion mounted on said first portion for movements with said first portion between a locking position in which said second portion is received within a notch of a blade and a releasing position in which said second portion is removed from the blade notch to a position beyond the notch of the blade, said release member being substantially in the form of a disc having an axis of rotation substantially normal to said handle axis and rotatably mounted on said blade holder for rotation about said release member axis of rotation, said first portion at least partially projecting above said upper edge of said blade holder to always be exposed for engagement by the user in both said blade locking and blade releasing positions when said release member is actuated while said blade holder is extended along said handle axis beyond said handle at a position spaced from said release button in the direction of the blade to be removed, and biasing means for normally moving said release member to move said second portion to said locking position, said handle having a thickness or width in a direction normal to said axis that is approximately 0.5″, whereby actuation of said release member by the finger of the user to overcome said biasing means moves said second portion to said releasing position for releasing the blade so that it can be withdrawn from said receiving means. 21. Retractable knife as defined in claim 20, wherein said blade holder has a thickness or width in said normal direction that is approximately 50% of said width of said handle. 22. Retractable knife as defined in claim 21, wherein said width of said blade holder is approximately 3/16″. 23. Retractable knife as defined in claim 20, wherein said knife defines an axis and has a longitudinal length along said axis of approximately 4.5″ in said retracted position of the blade. 24. Retractable knife as defined in claim 23, wherein said knife has a longitudinal length along said axis of approximately 6.25″ in said extended position of the blade. 25. Retractable knife as defined in claim 20, wherein said knife defines an axis and the longitudinal length along said axis in said retracted position of the blade is within the range of 35-45% of the longitudinal length in said extended position of the blade. 26. Retractable knife comprising a generally slim elongate handle having an upper edge generally proximate to the thumb of a user when held during normal use; defining a handle axis: a release button mounted for movements along said handle axis; a blade holder slidingly mounted within said handle responsive to actuation of said release button for sliding movements relative to said handle between a retracted position and an extended position in which at least a portion of said blade holder extends beyond said handle and having an upper edge, receiving means within said blade holder for receiving at least a portion of a blade provided with one edge formed with a cutting edge and opposing edge formed with a notch; a manually operable blade lock formed on said portion of said blade holder and comprising a rotatably mounted release member mounted on said blade holder, said release member having a first portion on said blade holder and mounted to be actuated by movement of a finger of the same hand of a user holding said handle along a direction substantially parallel to said handle axis, and a second portion mounted on said first portion for movements with said first portion between a locking position in which said second portion is received within a notch of a blade and a releasing position in which said second portion is removed from the blade notch to a position beyond the notch of the blade, said release member is substantially in the form of a disc having an axis substantially normal to said handle axis and rotatably mounted on said blade holder for rotation about said axis of rotation, said first portion at least partially projecting above said upper edge of said blade holder to always be exposed for engagement by the user in both said blade locking and blade releasing positions when said release member is actuated while said blade holder is extended along said handle axis beyond said handle at a position spaced from said release button in the direction of the blade to be removed, and biasing means for normally moving said release member to move said second portion to said locking position, said handle being formed with a gap or slot along at least a portion of said upper edge; and a release button extending above said upper edge and coupled to said blade holder, whereby actuation of said release button by the thumb of the user to slidingly move said blade holder while holding said handle slidably moves said blade holder between said retracted and extended positions.