Abstract: A writing instrument comprises a refill disposed slidably along the axial direction in an outer cylinder, a rotating cam set provided in the vicinity of the rear portion of the refill, a weighting balance placed in the vicinity of cam bar of the rotating cam set, a spring member for energizing rearwards the refill, and a knocking portion for operating the cam bar of the rotating cam set. According to the above construction of the writing instrument, when the writing instrument is shaken with force exceeding a certain level, gravity balance functions to project and retract the refill from the outer cylinder, while the refill may also be projected and retracted by knocking motions of the knocking portion.

Abstract: A lead propelling mechanism for a mechanical pencil includes a lead chuck, a ring fitted loosely about the chuck for tightening its head, a sleeve having a front end contacting the ring, and an elastic member having a front end bearing on the front end of the sleeve and a rear end held by a shoulder formed on the outer surface of the chuck adjacent to its rear end. The mechanism is very easy to assemble and join to a lead holding tube in the pencil. The rear end of the elastic member bears against an adjacent end of the tube to urge the ring to tighten the head of the chuck, when the chuck is inserted into the tube.

Abstract: A mechanical pencil reduced in the number of the component parts and facilitating the assembling work, comprising an outer cylinder, a replaceable lead cartridge, a tip member including a cushion member capable of contracting according to writing pressure that works on the lead so that the lead is retracted into the tip member when an excessive writing pressure works on the lead to prevent the breakage of the lead, and a lead feeding mechanism which is constructed within the tip member prior to the connection of the tip member to the outer cylinder.

Abstract: A mechanical pencil is constructed of (a) a decorative barrel to be held by a user; (b) a lead-feeding mechanism disposed within the decorative barrel; (c) a lead guide connected to the lead-feeding mechanism; and (d) a lead-containing cartridge having an outer diameter substantially equal to the inner diameter of the decorative barrel and held detachably in the decorative barrel. The mechanical pencil according to the present invention can be continuously used by simply replacing a used-up cartridge with a fresh cartridge containing a plurality of writing leads. Thus, it is unnecessary, different from conventional mechanical pencils, to insert a fresh supply of writing leads one by one into the mechanical pencil. Since a user is not required to touch writing leads directly, his hands are not smeared.

Abstract: A push-button type writing instrument is constructed of a refill received within a barrel slidably in the axial direction, a writing part receiving mechanism provided at a forward end portion of the refill, and sealing means provided with the writing part receiving mechanism for sealing a writing part. Owing to the provision of the sealing means, the ink of the writing instrument is kept free from evaporation and flow while the writing part is received within the barrel.

Abstract: A holder for spare lead comprises a hollow cylindrical holder body, said holder having an open end portion and a longitudinal groove formed on the inner wall along the axial direction of the holder body for locating only a suitable number of leads to a position from which the leads are taken out, and a cap body frictionally and rotatably mounted on the one end portion of the holder body. The cap body has an opening to dispense the spare lead from the groove.

Abstract: A knock type sharp pencil provided in its outer cylinder with a core holding mechanism composed of an inner cylinder coaxially arranged in the outer cylinder, a lead chuck inserted in the inner cylinder and including a chuck portion projecting out of the front end of the inner cylinder, a chuck ring inserted between a flange portion of the inner cylinder and the chuck portion of the lead chuck, a core case provided at its rear end with a knock portion and connected to the rear end of the lead chuck, and a spring means arranged in the inner cylinder and inserted between the flange portion of the inner cylinder and the front end portion of the core case, the spring means urging the core case backwardly.

Abstract: An automatic pencil which comprises a pointed end cap made of a synthetic resin material into which a lead pushing-out mechanism consisting of a lead chuck fixed to a lead container, a chuck ring externally fitted onto the lead chuck and a spring is inserted, a cushion stopper on the outer periphery of which and at one end thereof engaging projections are integrally formed so as to oppose to a plurality of engaging holes circumferentially provided around an open edge of the pointed end cap, and an outer tube into which the outer periphery of the backward end of the aforesaid pointed end cap is inserted to combine them with each other and, as a consequence, the resultant automatic pencil has a simple construction, so that it can easily be assembled.

Abstract: A clip for writing utensils such as a sharp pencil or the like comprising a clip piece including a pair of opposed insertion arms, said insertion arms being inserted into receiving grooves provided in side surfaces of a clip base formed integral with a holder of the writing utensil.

Abstract: A cutter knife comprising a band-shaped blade, a tubular holder for supporting said blade to make it movable in the axial direction thereof, an operating member for locating said blade at any desired position, and means for securing said operating member to any desired position with respect to said holder, said means including a series of engagement surfaces formed in said holder and located in a plane extending in a direction substantially perpendicular to the direction of movement of said operating member and a lug formed in said operating member and releasably engageable with one of said engagement surfaces.

Abstract: An automatic pencil employing axial movement of a lead piece guide and a lead piece chucking mechanism. After a length of protruding lead rod is used up, the lead piece guide is caused to retract in the same amount as the wearing away of the lead rod. By pressing the tip of the lead rod against another object, the lead rod is caused to move back with the chucking mechanism. After the rod is retracted until the tip aligns with the tip of the guide, the rod and lead piece guide will be moved back. The rod will then advance when the holder is moved away from the object while the lead piece guide will be left in the retracted position due to a large friction between the friction member and the guide means. By this operation, the rod is protruded from the guide at substantially equal length to the stroke of the retracting movement.

Abstract: A writing instrument includes a holding outer tube to be held by the user and a lead rod holding means, said lead rod holding means being provided in said holding outer tube and movable relative to said outer tube. The writing instrument has a lead rod feeding means; an engaging member for holding said lead rod holding mechanism at a position where a lead rod guiding pipe engages with an engaging surface formed on said holding outer tube when said lead rod guiding pipe advances to a position projected from said holding outer tube by pressing said lead rod holding means; and a push button provided for pushing said engaging member to release the engagement with said surface.