A speed-control knife structure with straight in-and-out motion, comprising:
- a housing, having an internal space in an interior thereof, a cutout on an end face of the housing and a blade exit on a side of the housing, wherein the internal space communicates with the cutout and the blade exit;
- an inner blade holder, installed in the internal space, wherein the inner blade holder has both ends assembled to the housing and is provided with a track hole extending from a top end to a bottom end of the inner blade holder;
- an upper guide plate, installed in the internal space and spaced from the track hole of the inner blade holder, wherein the upper guide plate is cut with a slide channel that corresponds to and communicates with the cutout and includes a control part that corresponds to the cutout and partially extends out of the cutout and becomes exposed from the housing;
- a knife assembly, including a blade and a sliding block, wherein (i) a part of the sliding block is slidably disposed in the track hole, while another part of the sliding block protrudes out of the track hole toward the upper guide plate, (ii) the blade is disposed on one side of the inner blade holder and opposite to the part of the sliding block that protrudes, (iii) the blade has one end assembled to the sliding block and the other end facing the blade exit, and (iv) the sliding block is movable along a profile of the track hole to drive operable extension and retraction of the blade through the blade exit;
- a push control member, having a part disposed in the internal space and another part protruding from the housing, wherein the push control member is located between the upper guide plate and the sliding block, allowing an axle pin to penetrate through the blade, the sliding block and the push control member, and when the upper guide plate moves toward the blade exit, the upper guide plate contacts the part of the push control member protruding from the housing during the movement, indirectly driving movement of the sliding block along the track hole;
- two push blocks, each detachably interlocked to the upper guide plate, located between both ends of the slide channel, and having a part interlocked within the slide channel and another part protruding downward from the upper guide plate into a gap between the upper guide plate and the inner blade holder, wherein an elastic member is installed within the slide channel and has both ends hooked onto the two push blocks, respectively;
- and
- a trigger clip, disposed between the sliding block and the upper guide plate, allowing an axle rod to penetrate through the blade, the sliding block and the trigger clip, wherein the trigger clip is configured to pivot relative to the axle rod and has a part interlocked to an end of the track hole when the blade has not yet moved toward the blade exit;
- wherein the control part is configured to drive the upper guide plate to move toward the blade exit, pushing the push block near the blade exit and the push control member by the upper guide plate;
- when the push block is pushed and moved, the elastic member is pulled, which generates elastic force, and simultaneously, the push control member is pushed and thus indirectly drives the blade to move and the trigger clip disengages from the track hole and pivots;
- and the elastic force of the elastic member then instantly pulls the push block located far from the blade exit to allow the push block to push the sliding block, thereby the blade quickly protruding from the blade exit.