Patent ID: 8893391

Claim:
A rotary knife comprising: a handle; a rotatable annular blade; and a blade carrier assembly including an expandable blade housing operably coupled to the handle and configured to removably support the blade, said blade housing being movable relative to the handle between a blade-securing condition, in which the blade housing securely supports the blade for rotational operation, and a relatively expanded blade-releasing condition, in which the blade housing permits removal and installation of the blade relative to the blade housing, said carrier assembly including a lever mechanism shiftably mounted relative to the handle and configured when shifted to expand the blade housing from the blade-securing condition to the blade-releasing condition, said lever mechanism engaging the blade housing to move the blade housing from the blade-securing condition to the blade-releasing condition, said blade housing being generally annular in shape and presenting adjacent housing ends that are moved away from one another when the blade housing expands from the blade-securing condition to the blade-releasing condition, said blade housing defining a follower surface, said lever mechanism presenting a cam surface that engages the follower surface when the lever mechanism is shifted in a first direction to thereby cause the housing ends to separate, said lever mechanism being pivotal between open and closed positions, with the lever mechanism moving in the first direction from the closed position to the open position, said blade housing being resiliently expanded when the housing ends are separated by the lever mechanism, such that the blade housing exerts a force against the lever mechanism, said lever mechanism having an over-center position spaced between the open and closed positions, with the force exerted by the blade housing urging the lever mechanism in the first direction when the lever mechanism is positioned between the over-center and open positions, and with the force exerted by the blade housing urging the lever mechanism in an opposite second direction when the lever mechanism is positioned between the over-center and closed positions.