Patent ID: 8701293

Claim:
A knife comprising: a blade having first and second cutting edges located at opposite ends of the blade, an elongated handle having two opposing sides and including a cavity, an elongated slot and first and second opposing ends, one side of the handle having a first locking recess located at a first locking point, and a first lock-release button supported by the handle and being accessible to a user, and the handle having a second locking recess located adjacent the slot and at a second locking point; a shuttle affixed to the blade and slidable within the cavity between the first and second opposing ends, the shuttle including: a first locking tab that is biased to engage with the first locking recess when the shuttle moves into alignment with the first locking point, and an arm that projects through the slot, the arm being accessible to the user during use of the knife and also being slidable within the slot, the arm being linearly displaceable with respect to the handle between a locked orientation and a released orientation, the arm including a second locking tab sized and shaped to engage with the second locking recess when the arm moves into alignment with the second locking point, and a spring bias that forces the second locking tab towards engagement with the second locking recess when the arm is located at the second locking point, the engagement of the first locking tab with the first locking recess and the engagement of the second locking tab with the second locking recess immobilizes the shuttle and blade with respect to the handle until the first lock-release button and the second lock-release button are simultaneously depressed, depressing the first lock-release button disengages the first locking tab from said first locking recess and depressing the second lock-release button disengages the second locking tab from the second locking recess to allow sliding movement of the blade with respect to the handle; the location of the first lock-release button being stationary with respect to the handle regardless of the location of the shuttle within the handle; the first locking tab engages said first locking recess at the same time that the second locking tab engages the second locking recess when the shuttle slides to a point between the two opposing ends and the cutting edges are disposed within the housing.