Abstract: A manipulator of a compass for drawing a circle or a compass-cutter for cutting an object in circular configuration is provided with a mechanism for transmitting the force from the user's hand only in one direction. With such the construction, a user can smoothly draw a complete circle at 360 degree, or can cut a paper, a cloth and so on in circular configuration, without re-pinching the manipulator during operation, in a manner for a ratchet which is a commercially available tool.

Abstract: A manipulator of a compass for drawing a circle or a compass-cutter for cutting an object in circular configuration is provided with a mechanism for transmitting the force from the user's hand only in one direction. With such the construction, a user can smoothly draw a complete circle at 360 degree, or can cut a paper, a cloth and so on in circular configuration, without re-pinching the manipulator during operation, in a manner for a ratchet which is a commercially available tool.

Abstract: A manipulator of a compass for drawing a circle or a compass-cutter for cutting an object in circular configuration is provided with a mechanism for transmitting the force from the user's hand only in one direction. With such the construction, a user can smoothly draw a complete circle at 360 degree, or can cut a paper, a cloth and so on in circular configuration, without re-pinching the manipulator during operation, in a manner for a ratchet which is a commercially available tool.

Abstract: A cutter knife in which a blade connected to a slider is slidably held in an elongated sleeve member. The slider is provided with a first engagement protrusion and a second engagement protrusion located on a forward end and a backward end in the sliding direction of the slider, one of which is to be inserted into a connection hole of the blade for connecting the slider and the blade. The distance from each of the first and the second engagement protrusions to the inner surface of the sleeve member when the slider is inserted into the sleeve member is smaller than the distance between the connection hole and the back of the blade. This results in biasing the blade back against the inner surface of the sleeve member for protecting the blade edge. When the inserting direction of the slider is reversed, the biasing direction of the blade is also reversed.

Abstract: A cutter knife of which a blade connected to a slider is slidably held in an elongated sleeve member. The slider is provided with a first engagement protrusion and a second engagement protrusion located on a forward end and a backward end in sliding direction of the slider, one of which is to be inserted into a connection hole of the blade for connecting the slider and the blade. A distance from each of the first and the second engagement protrusions to the inner surface of the sleeve member when the slider is inserted into the sleeve member is set smaller than a distance between the connection hole and a back of the blade, and thereby the blade back is biased against the inner surface of the sleeve member for protecting the blade edge. When inserting direction of the slider is reversed, biased direction of the blade is also reversed.

Abstract: A manipulator of a compass for drawing a circle or a compass-cutter for cutting an object in circular configuration is provided with a mechanism for transmitting the force from the user's hand only in one direction. With such the construction, a user can smoothly draw a complete circle at 360 degree, or can cut a paper, a cloth and so on in circular configuration, without re-pinching the manipulator during operation, in a manner for a ratchet which is a commercially available tool.

Abstract: A gripping type of cutter knife wherein a knife blade can be locked into both the retracted and projected positions. This cutter knife includes a locking mechanism of which construction and handling are simple. In this cutter knife, a knife blade is projected by grasping, against spring force, a trigger lever projected from the grip portion of the cutter body. This cutter knife is characterized in that it has a push-type locking mechanism which is selectively held in “unlocking position” wherein the trigger lever is allowed to swing, or “locking position” wherein the swing is prohibited.