Abstract: An input pen is capable of being held in any one of input pen holding parts, respectively having different shapes, of various personal digital assistants. The input pen has a barrel, and stopping members fitted in opposite end parts of a metal tube. An elastic member is placed between the stopping members so as to push the stopping members outwardly. The metal tube is fitted in openings formed in the barrel. When the input pen is inserted into an input pen holding part of the personal digital assistant, the stopping members, properly projecting exteriorly through the openings of the barrel, are pressed against an inner surface of the input pen holding part. Thus, the input pen will not move even if there is a space between the barrel and the inner surface of the input pen holding part.

Abstract: A pen cylinder has at its front end a front input member made of a synthetic resin and at its rear end a rear input member made of a soft elastic material such as rubber. When performing an input operation onto a hard panel or an input operation of fine letters, an accurate input is achieved by using the front input member of synthetic resin provided on the front end of the pen cylinder. When performing input onto a soft panel or pointing input, an input free from damage to the panel is achieved by using the rear input member composed of soft elastic material.

Abstract: A input pen for a portable information processing terminal device with an input tip (12) biased axially forward by pressure applied thereto by a return spring (13). The pressure applied to the input tip (12) is optionally adjustable. A front barrel 10 is detachably attached to a front portion of a barrel (1). The input tip (12) is axially slidably inserted in the front barrel 10. The return spring 13 extended in the front barrel (10) applies pressure to the input tip (12) so as to bias the input tip (12) forward.

Abstract: In an input pen for transmitting to a tablet 19 information of variation in writing pressure as well as information of designated positions, a joint 10 is mounted on the rear end of a shaft a writing tip 12. A movable magnetic core 9 is attached to the joint 10. A push rod 13 is passed in the pen body in such a manner that longitudinal position of the push rod is controllable, with a resilient member 11 interposed between the push rod 13 and the joint 10. Longitudinal position of the push rod 13 is adjusted in order to control the load upon mounting of the resilient member 11. It is thus possible to control the load upon mounting of the resilient member 11 biasing the writing tip 12 forward by adjusting the position of the push rod 13, whereby the resilient member 11 can be mounted constantly under a predetermined load independently of variation in dimensions of components. A reliable detection of writing pressure applied to the writing tip 12 by operator's hand is therefore made possible.

Abstract: A writing instrument with an input member for pressure-sensitive handwriting at one end, and a removable writing pen on the opposite end of a cylindrical body. A single cap of a diameter smaller than that of the cylindrical body may cover either the writing pen or the input member. The diameter of the cap is smaller that the diameter of the cylindrical body to lessen the chance of it being inadvertently dislodged.

Abstract: A longitudinal opening window (1B) is formed a: a rear end portion of a cylindrical casing (1) of a mechanical pencil. At the rear end of the cylindrical casing (1), an eraser holder (12) is disposed in such a way that it can move forward and rearward for a predetermined distance. At the rear end of the eraser holder (12), a rubber eraser (13) is mounted. At the front of the eraser holder (12), a cylindrical small diameter front portion (12B) is provided. On the outside of the small diameter front portion (12B) is disposed a stop portion (12D) protruding outwardly on a resilient piece (12C). The stop portion (12D) engages with the opening window (1B). The rear end of a lead reservoir (10) connected to the rear portion of a chuck (7) extends to the inside of the small diameter front portion (12B). When the cylindrical casing (1) is shaken, a weight (11) surrounding the lead reservoir (10) moves forward, thereby causing the chuck (7) to move forward.

Abstract: In a mechanical pencil, a tubular lead reservoir is connected to the rearward end of a lead chuck. A cylindrical weight is fitted slidably around the lead reservoir and is adapted to strike against the chuck to open the same to allow forward feed of the lead when a forward shake is applied to the pen barrel. In order to prevent forward feed of the lead as a result of unintended forward shake while carrying the pencil, a slider disposed rearwardly of the lead reservoir has a radially outwardly extending engagement projection which is adapted to slidably engage either a longitudinal guide slot in the pen barrel or a lateral slot circumferentially and rearwardly extending in the pen barrel. When the engagement projection is in engagement with the lateral slot, the chuck is caused to take an advanced position in which the chuck is open so that a forward stroke cannot feed the lead forward.

Abstract: A mechanical pencil has a body with a lead storage chamber defined therein for housing spare lengths of lead, and a tubular lead guide receiving a length of lead and coaxially mounted in the body so as to partly protrude outwardly from its writing end. During writing or marking, the lead guide gradually retracts into the body against the force of a return spring with the wear of the lead received therein and, when the pencil is moved off the writing surface, it is held in place by a locking mechanism until a preselected wear point is reached, then it is sprung back to its normal position. Disposed intermediate the lead storage chamber and the lead guide, a chuck coacts with an internally tapered socket for gripping the lead against displacement away from the writing end of the body.

Abstract: A mechanical pencil with automatic lead feed has a clamping mechanism for clamping a lead in such a manner that it holds the lead steadily against rearward movement but easily permits the lead to move forwardly. A lead tube is fixed at its rear end to the front end of a housing to guide and protect the lead. A sensor is slidably held in the front end of the housing and extends along the lead tube to sense the wear of the lead during writing. A lead advancing mechanism is actuated by the sensor and has a holder for frictionally holding the lead and an elastic member for urging the holder forwardly.

Abstract: A lead-feeding mechanism comprising a lead reservoir, a connector, and a chuck in a mechanical pencil is held by a front spring in a normal rear position, at which the chuck is clamping a lead piece, but when a forward shake is imparted to the pencil, a weight collides forwardly with the lead-feeding mechanism and pushes the same forward, counter to the force of the spring, whereupon the chuck feeds the lead piece through a specific distance then releases the same, the lead-feeding mechanism being subsequently returned by the spring to the normal position, where the chuck again clamps the lead piece at a new position thereof.