Utility knife

Claim 1

In a knife comprising a knife blade, an elongated handle having a blade position adjusting recess extending longitudinally along the handle and an interior latching surface adjacent the recess, a blade carrier mounting the blade for slideable movement relative to the handle, said carrier including a latching member cooperating with the latching surface for releasably latching the blade in one of a plurality of selected positions, and an operating member secured to said latching member and adapted for moving the latching member out of engagement with the latching surface and for moving the blade carrier along the handle, the combination wherein said operating member includes a stem portion and an enlarged head portion rotatably mounted on the stem portion, said stem portion having a top shoulder with an integral, inverted frustoconical spindle projecting upwardly therefrom and said head having a complementary frustoconical aperture of substantially the same size, said spindle being nonreleasably positioned within said aperture with said head engaging said spindle and said top shoulder to prevent axial displacement of said head from said spindle while permitting relative rotation therebetween, said head having a width less than the width of said recess to permit movement into and along said recess during movement of the blade between selected positions and a length greater than the width of said recess, said frustoconical spindle and aperture connection permitting rotation of said head into a recess-bridging locked position only when said latching member is positioned within one of said selected latching positions, said head in its recess-bridging locked position cooperating with said handle to prevent depression of said stem and inadvertent unlatching of the latching member for movement of the blade out of its selected position.