Patent ID: 6886257

Claim:
A knife comprising: a handheld housing having a front end and a rear end, the housing serving to accommodate several blades therein, each blade having a notched section, the front end having an opening; a slidable pushing mechanism disposed on the housing and including an activating section and a moving section, the activating section outward protruding from the housing and being manually movable between the front end and the rear end, the activating section being manually engageable with the housing, whereby the pushing mechanism can be fixed in a first position or a second position of the housing, the moving section being connected with the activating section and positioned inside the housing, whereby when the pushing mechanism is positioned in the first position, the moving section is adjacent to the blades for engaging with the notched section and pushing one of the blades to the second position and protruding the blade from the front end through the opening thereof; a resilient section disposed on inner side of the housing, whereby when the pushing mechanism is positioned in the first position, the resilient section serves to transversely push the blades toward the moving section; and a releasing mechanism transversely reciprocally movably disposed on the housing, when the pushing mechanism is positioned in the second position, the releasing mechanism serving to push the moving section to release the blade from the moving section, whereby the blade can be pulled out from the opening of the front end, said knife being characterized in that a pair of guide rails spaced from each other by a certain distance are disposed in the housing between the front end and the rear end, a slide block being disposed on the moving section; each guide rail has a transverse bent section between the first and second positions of the housing, the bent section being obliquely bent toward the resilient section; the slide block is transversely slidably disposed on the moving section and positioned between the guide rails, the slide block having a sliding section and an insertion section; the sliding section is disposed on two opposite sides of the slide block for abutting against the guide rails, whereby after the slide block passes through the bent section, the slide block is displaced in a transverse direction of the housing; and the insertion section is disposed on the slide block corresponding to the notched section, whereby when the slide block is displaced, the insertion section is inserted into the notched section by different depths for engaging with one of the blades.