| 主权项 |
1. A self-loading utility knife comprising: an elongate handle having an internal chamber generally defining an axis and an upper edge extending along a predetermined length of said axis, one end of said handle being a remote end formed with a generally flat aperture suitable for the passage of an active blade with clearance and a notch in said upper edge proximate to said flat aperture and the other end of said handle being a proximate end, said generally flat aperture defining a cutting plane extending through said handle along said axis; a blade-holder slidably mounted within said chamber for movements in directions along said axis between an extended position and a retracted position, said blade holder being adapted to secure a single active blade for movement through said aperture when said blade holder is in said extended position; a blade-holder release button generally arranged along said cutting plane and coupled to said blade holder, said release button having an outer portion that is located exteriorly of said handle, said release button being slidingly movable relative to said handle along said predetermined length to cause said blade holder to move to selected positions between said retracted position and said extended position, said handle being provided to one side of said cutting plane with a blade compartment open to said chamber and arranged at a predetermined position along said axis between said remote and proximate ends and generally dimensioned and configured in the shape of said active blade for receiving a plurality of stacked spare blades arranged generally parallel to said cutting plane so that the spare blades in said blade compartment are shifted transversely relative to said axis into said chamber, said blade holder being provided with a recess having a depth no greater than the thickness of one blade and shaped to correspond to at least a portion of a blade closest to said proximate end to allow at least a portion of a single blade to be received in a retaining relationship within said recess to cause the blade received within said recess to follow the movements of said blade holder; an access cover on said handle for selectively opening and closing said blade compartment for insertion or removal of spare blades; biasing means provided on said access cover for biasing blades within said blade compartment inwardly in the direction of said blade holder when said access cover is in its closed position; locking means for selectively maintaining said access cover in closed or open positions; and a blade releasing means on said blade holder wherein when said blade holder is in the extended position the blade releasing means is located in said notch above a portion of the upper edge defined by the notch such that the blade releasing means will release a blade from the blade holder when a user's thumb draws the blade releasing means rearwardly towards the proximate end of the handle, and when the blade holder is in the retracted position the blade releasing means is located entirely below the portion of the upper edge not defined by the notch, said blade holder only receiving a single blade within said recess, said blade holder being movable to a position juxtaposed to said blade compartment when said blade holder is in a predetermined retracted position in registry with said recess, whereby after an active blade has been removed through said flat aperture said biasing means are caused to automatically move a spare blade along a direction transversely to said axis into said recess for movement to an operative position through said flat aperture when said blade holder is moved to said extended position and movement of said blade holder and release of a blade in said extended position can be implemented through a one handed operation. |
