Abstract: Disclosed is a blade snap-off holder which enables a safe, easy and smooth operation for snapping off a blade tip of a cutter knife. The holder has an insertion opening on its wall. A tip of a knife blade inserted through the opening is received in a groove of a rotary member located inside the holder. The rotation axis of the rotary member extends substantially parallel to the score of the knife blade. When the rotary member is rotated and a bending force is applied to the tip of the knife blade, the blade tip received in the groove of the rotary member can be snapped off. A user only grasps this holder in one hand and rotates the operation lever with a finger, and then a blade tip can be snapped off cleanly and easily without any subtle control of a force.

Abstract: A rotary cutting mat of the present invention has a base plate and a rotary mat, which can be rotated relative to each other. The rotary mat is provided with a shaft member projected from a reverse side thereof. The base plate is provided with a receiving portion, which rotatably receives the shaft member of the rotary mat. Since the rotary mat is simply placed on the base plate with the shaft member being inserted in the receiving portion, there is no need of a rivet for connecting the rotary mat and the base plate. Thus, the constitution on the mat is simplified and the surface of the mat can be maintained flat without any buried rivet head in the mat.

Abstract: In the safety cutter knife provided, a blade slide holding a blade is rotated in the direction nearly perpendicular to the longitudinal center line of the housing of the cutter knife by virtue of a reaction force from a work material when the cutting edge of the blade extended from the housing is pressed into the work material while the blade slide and the actuator slide are located at the extended position. With this rotation of the blade slide, the engagement between the blade slide and the actuator slide is released, such that the blade slide with the blade can return automatically from the extended position to the retracted position by virtue of the energizing force of a spring when the blade is released from the work material.

Abstract: A cutter knife for making slash-quilts is provided, which has a plurality of guide members having different width dimensions. Further, a plurality of slits are formed between each of the guide members and the casing of the cutter knife, in each of the slits a blade edge is exposed. Since one cutter knife is provided with a plurality of guide members having different widths, the one cutter knife can be widely used for making a variety of slash-quilts having different pitch widths between stitch lines, without need for exchanging the guide members. A user can select one guide member having a suitable width dimension for a certain pitch width between the stitch lines, and insert the selected guide member between the stitch lines of a quilt. Then, the user pulls the cutter knife backward to himself, or pushes it forward to cut the quilt, and the slash-quilts is made.

Abstract: A cutter knife with a blade extendable from and retractable into a cutter knife body by operating a slider. The cutter knife body has a plurality of engagement indentations formed alongside a slit. The slider has a spring member with an engagement head which is engageable with one of the engagement indentations. When an external force is directly applied to the blade in an advancing direction, the blade is inhibited from sliding out, because the distal side of the engagement head comes into contact with the distal end wall of the engagement indentation. When a predetermined external force is directly applied to the blade in a retracting direction, the blade can be withdrawn and held inside the cutter knife body by this external force, because an escapee is provided to the proximal end wall of each engagement indentation, or to the proximal side of the engagement head.

Abstract: A cutter knife which allows the blade to be drawn out of or withdrawn into the cutter knife body by operating the slider. The cutter knife body has a plurality of engagement indentations formed at regular intervals alongside a slit extending in a longitudinal direction. On the other hand, the slider has a spring member provided with an engagement head which is to be engaged with one of the engagement indentations. When an external force is directly applied to the blade in the advancing direction of the blade, the blade is inhibited from sliding out, because the distal side of the engagement head comes into contact with the distal end wall of the engagement indentation.

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.