Abstract: The present invention provides a knife with a replaceable blade which is spring-biased in the retracted position. The knife is designed such that the blade can only be extended by exerting a downward force and by turning the handle with respect to an inner housing. The handle has a tab affixed to the inside wall of the handle. The inner housing has an angled slot in its wall adapted to receive the tab. When the blade is fully retracted, the tab rests on the shoulder at the top of the inner housing. A straight downward pressure on the handle causes the tab to engage the shoulder and will not allow the blade to extend. When the handle is rotated, the tab enters the slot and the blade is forced downward. As this occurs, the blade extends through a slot at the bottom of a blade cover. When the blade is removed from the object to be cut, the spring forces the handle to move with respect to the inner housing and causes the blade to retract within the blade cover.

Abstract: The present invention provides a knife with a replaceable blade which is spring-biased in the retracted position. The knife is designed such that the blade can only be extended by exerting a downward force and by turning the handle with respect to an inner housing. The handle has a tab affixed to the inside wall of the handle. The inner housing has an angled slot in its wall adapted to receive the tab. When the blade is fully retracted, the tab rests on the shoulder at the top of the inner housing. A straight downward pressure on the handle causes the tab to engage the shoulder and will not allow the blade to extend. When the handle is rotated, the tab enters the slot and the blade is forced downward. As this occurs, the blade extends through a slot at the bottom of a blade cover. When the blade is removed from the object to be cut, the spring forces the handle to move with respect to the inner housing and causes the blade to retract within the blade cover.