JP4670312B2 - mechanical pencil - Google Patents

Description

  The present invention relates to a mechanical pencil that feeds a lead, and more particularly, to a mechanical pencil in which a knock member that operates a lead feeding means is arranged on a side surface of an intermediate portion of a shaft cylinder.

Conventionally, an axial rack is formed on the side surface of the chuck that holds the pencil lead, the chuck is slidably accommodated in the shaft cylinder, and the chuck collar and the step on the inner surface of the shaft cylinder A spring that presses the chuck in the direction of the tail end is stretched between them, and a clamping ring whose axial movement range is limited by a step on the inner surface of the shaft tube is fitted to the chuck, and the shaft tube The fan-shaped gear that meshes with the rack is held by a shaft attached in a direction perpendicular to the shaft cylinder, and the fan-shaped gear is attached to the inner surface of a cover that is attached to the side surface of the shaft cylinder so as to move in a direction perpendicular to the axis. 2. Description of the Related Art There is known a feeding mechanism pencil that is provided with the ends of arms protruding from gears facing each other.
Actual Kosho 52-15864.

However, in the above-described conventional technology, it is necessary to align the sector gear and the rack at the time of assembly, and time is spent on the assembly, resulting in poor productivity. That is, the fan gear and the rack must be aligned and assembled in consideration of the position where the lead is not extended when not in use and the state where the lead is extended when in use, that is, the position of both. There wasn't.
In addition, since the cover and the arm of the sector gear are in contact with each other, the sector gear and the rack must be aligned and assembled while taking into consideration the pressing operation amount of the sector gear by the cover, further reducing the productivity. It was.

According to the present invention, a rotating body that rotates parallel to the axis is disposed on the side surface of the intermediate portion of the shaft cylinder so as to be exposed from the surface of the shaft cylinder, and the core feeding means is operated by the rotating operation of the rotating body. The mechanical pencil has at least a lead feeding means comprising a slide member, a chuck body that is press-fitted in front of the slide member to grip and release the lead, and a chuck ring that opens and closes the chuck body. The sliding member is formed with an engaging projection, the rotating body is formed with a cam blade, and the cam blade of the rotating body is brought into contact with and pressed against the engaging projection of the sliding member, The gist is that the chuck body is advanced, and the lead is advanced by advancement of the slide member and the chuck body.

According to the present invention, a rotating body that rotates parallel to the axis is disposed on the side surface of the intermediate portion of the shaft cylinder so as to be exposed from the surface of the shaft cylinder, and the core feeding means is operated by the rotating operation of the rotating body. The mechanical pencil has at least a core feeding means comprising a slide member, a chuck body that is press-fitted in front of the slide member to grip and release the core, and a chuck ring that opens and closes the chuck body. The sliding member is formed with an engaging projection, the rotating body is formed with a cam blade, and the cam blade of the rotating body is brought into contact with and pressed against the engaging projection of the sliding member, Since the chuck body is advanced and the lead is advanced by the advancement of the slide member and the chuck body, the positioning of the rotating body and the core supply means is extremely high. It can be done easily, as a result, it is possible to provide a mechanical pencil with excellent productivity.

  The operation will be described. By rotating the rotating body in one direction, the lead feeding means moves back and forth to feed the lead.

A first example will be described with reference to FIGS. The rear portion of the shaft cylinder 1 is a core tank portion 2 having a substantially octagonal cross section, and a cap 3 is detachably fitted into the rear end opening. The clip 3 is integrally formed with the cap 3, but it may be formed of a separate member and fixed to the cap 3 by means such as press fitting. The cap 3 is always fitted at a fixed position with respect to the circumferential position of the shaft tube 1, and a rotating body to be described later is always positioned on the extension line of the clip. This prevents a sense of incongruity caused by the clip during the lead feeding operation.
On the other hand, the tip member 5 is detachably attached to the front end portion of the shaft tube 1 by means such as screwing, but may be fixed by means such as press fitting. Inside the tip member 5, a core detent member 6 made of a rubber-like elastic body that prevents retraction of the lead core is arranged by means such as press fitting, but a rib or the like is integrated with the inner surface of the tip member 5. By forming the rib, the rib may be used as a core detent portion. Further, an abutting step portion 7 is formed on the inner surface of the tip member 5 to restrict the forward movement of the chuck ring described later. Further, a core protection tube 8 made of stainless steel or the like is press-fitted and fixed to the tip of the tip member 5, but the core protection tube 8 may be integrally formed with the tip member 5. By providing the core protection tube, the visibility of the core during writing is improved.

Further, a core feeding means 9 is arranged inside the intermediate portion of the shaft tube 1 so as to be movable back and forth. The lead feeding means 9 will be described in detail. The lead feeding means 9 includes a lead receiving member 10 for separating a plurality of leads stored in the lead tank 2 one by one, a slide member 11 press-fitted in front of the lead receiving member 10, and a slide thereof. The chuck body 12 is configured to grip and release the core press-fitted in front of the member 11, and the chuck ring 13 is configured to open and close the chuck body 12. The core receiving member 10, the slide member 11, The chuck body 12 and the like are urged rearward by an elastic member 14 such as a coil spring.
Here, the core receiving member 10 has an octagonal shape that is substantially the same as the cross-sectional shape of the core tank 2, and engaging projections 15 that engage with a rotating body (to be described later) are formed on both side surfaces of the slide member 11. Although formed, the engaging projection 15 is formed with an inclined surface 16 rising toward the right side in FIG. 1 (FIG. 3). The engaging protrusion 15 has an inclined surface 16 in this example, but may be an arcuate curved portion, an engaging protrusion having a circular cross section, or a cross section. May have a plate shape such as a square or a rectangle.

On the other hand, a window hole 17 is formed in an intermediate portion of the shaft cylinder 1, and a rotating body 18 is disposed in the window hole 17 in a state of being exposed from the shaft cylinder 1. The rotating body 18 is rotatably supported on a rotating shaft J fixed to the shaft cylinder 1, but is disposed so as to straddle the slide member 11. That is, although it is constituted by two rotating bodies 18, it may be constituted by one rotation. In consideration of rotational operability and rotational stability of the rotating body, the rotating body 18 is composed of two rotating bodies 18. The rotating body 18 is composed of a disk portion 19 located on the outside and a cam blade 20 that is integrally formed on the inside of the disk portion and abuts against the inclined surface 16 of the engaging projection 15 of the slide member 11. in the present embodiment the cam blades 20 are formed five radially, may be a four without being limited to此, it may be a six. Incidentally, the lead feeding amount is increased by reducing the number of cam blades 20, and on the contrary, a fine lead feeding amount can be obtained by increasing the number of cam blades 20. What is necessary is just to select suitably according to a use condition, for example, when a core diameter is generally 0.5 mm, it can extend many, and it should just be able to extend less when a core diameter is 0.2 mm thin like drawing. The front surface of the cam blade 20 is formed in an arc shape (arc portion 21), but may be an inclined surface or a simple plate shape. However, it is preferable to use the arc portion 21 because the feeding operation force is light at first and gradually becomes heavier.
In this example, the window hole 17 is formed for each rotating body 18, that is, divided into two, but may be connected to form one window hole. However, it is preferable to form each of them in consideration of the appearance and the lateral vibration of the rotating body 18. Alternatively, the rotating shaft may be integrally attached to the rotating body 18 so as to be rotatably attached to the shaft cylinder 1. The cost of parts is reduced and the assembly is improved.
Further, in this example, the rotating body 18 is formed from the disk portion 19, but it may be a polygonal shape such as a hexagonal shape or a decagonal shape. It is good also as a shape. Also, the upper circumferential edge of the disk portion 19 may be covered with a rubber-like elastic body, or knurled or non-finished, so that it can be prevented from slipping on the finger, improving operability and improving appearance. To do.

Next, the operation will be described. When the rotating body 18 is rotated in the clockwise direction, the cam blade 20 of the rotating body rotates and the engaging protrusion 15 is advanced while pressing the inclined surface 16. At this time, the slide member 11 and the chuck body 12 also move forward against the elastic force of the elastic member 14. As the chuck body 12 moves forward, the lead is unwound, and eventually the chuck ring 13 comes into contact with the contact step 7 to expand the chuck body 12 and release the lead. When the rotating body 18 is rotated about 45 degrees, the cam blade 20 is detached from the inclined surface 16 of the engaging protrusion 15. At this moment, the slide member 11 and the expanded chuck body 12 are retracted and returned by the elastic member 14. Here, if the rotating body 18 is further rotated, the above-described operation, specifically, the lead feeding operation is repeated . Thus, by rotating the rotating body 18, the cam blade 20 and the engaging protrusion 15 are intermittently engaged and released, and the lead is drawn out. That is, the cam blade 20 is not always in contact with the inclined surface of the engaging protrusion 15 but is in contact / engagement only when the core is extended, and after the extension, the engaging protrusion 15 (inclined surface 16). You are leaving.

  Here, in the present invention, since the lead feeding operation is performed by rotating the rotating body 18, for example, it is said that the lead feeding due to an unexpected pressing operation when the mechanical pencil is inserted into a pocket or the like is prevented. It also has the effect. That is, even if a pressing operation is applied to the rotating body 18 from the outside of the pocket, the lead is not drawn out.

The longitudinal half sectional view of the present invention. FIG. 2 is a front longitudinal half cross-sectional view of the main part of FIG. 1. FIG. 3 is a sectional view taken along line AA in FIG. 2. The principal part perspective view of FIG. The principal part perspective view of FIG.

DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Core tank part 3 Cap 4 Clip 5 Tip member 6 Core detent member 7 Contact step part 8 Core protection tube 9 Core feeding means 10 Core receiving member 11 Slide member 12 Chuck body 13 Chuck ring 14 Repelling member 15 Engagement protrusion 16 Inclined surface 17 Window hole 18 Rotating body 19 Disk part 20 Cam blade 21 Arc part

Claims (4)

A rotating body that rotates parallel to the axis line is disposed on the side surface of the middle part of the shaft cylinder in a state exposed from the surface of the shaft cylinder, and a mechanical pencil in which the core feeding means is operated by the rotating operation of the rotating body. The lead feeding means comprises at least a slide member, a chuck body that is press-fitted in front of the slide member to grip and release the lead, and a chuck ring that opens and closes the chuck body, and the slide member An engaging protrusion is formed on the rotating body, a cam blade is formed on the rotating body , and the sliding member and the chuck body are moved forward by abutting and pressing the cam blade of the rotating body against the engaging protrusion of the sliding member. A mechanical pencil that pushes out the lead by advancing the slide member and the chuck body. The mechanical pencil according to claim 1, wherein the rotating body can rotate in only one direction. The mechanical pencil according to claim 1 or 2, wherein the rotating body and the core feeding means are intermittently engaged and disengaged. The cam blade of the rotating body or the engagement surface of at least one of the engagement protrusions of the core feeding means is formed by bending or inclining. Mechanical pencil.

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