JP3785138B2 - mechanical pencil - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical pencil in which a sleeve constituting a core feeding mechanism is locked and fixed to a shaft cylinder.
[0002]
[Prior art]
Conventionally, in a mechanical pencil in which the sleeve has not been fixed to the core feeding mechanism, the locking portion for restricting the front end of the moving range of the chuck ring is formed by a step portion formed on the inner periphery of the shaft tube or the tip. Therefore, in order to obtain a constant core feed amount, it is necessary to increase the processing accuracy of the shaft cylinder or the tip tool and accurately regulate the mounting position of the core feeding mechanism with respect to the shaft cylinder or the tip tool. There was an inconvenience. (For example, see Patent Document 1)
[0003]
Also , when inserting from the rear of the shaft cylinder to set the core feeding mechanism, the directionality could not be ignored and could not be easily assembled, which made the internal structure of the shaft cylinder very complicated. . (For example, see Patent Document 2)
[0004]
Furthermore, the rear portion of the sleeve, so were not provided with a guiding means of the fixing and the lead tank of the barrel, it can not be performed reliably fixed to the barrel a short distance (length), always lead tank Since the tip of the sleeve is not held in the sleeve, the chuck spring does not operate reliably and the knocking operation is not stable. That is, a locking piece for fixing the sleeve to the shaft cylinder protrudes from the rear outer wall of the sleeve, and the sleeve is dropped into the shaft cylinder from the rear, and the locking piece is formed on the inner wall of the shaft cylinder. When passing through the annular rib, the inner diameter of the locking piece portion is increased so as not to come into contact with a member attached to the sleeve member in order to reduce or deform the diameter. On the other hand, in order to securely hold the chuck attached to the sleeve, the chuck retaining spring, the lead tank, etc., the tip of the lead tank is positioned forward of the locking piece (the portion with the larger inner diameter) of the sleeve. It was necessary to extend the entire length of the sleeve member. (For example, see Patent Document 3)
[0005]
Prior art document information related to the invention of this application includes the following.
[Patent Document 1]
Japanese Utility Model Publication No. 58-39913 (column 3, line 9 to line 24, column 5, line 14 to line 21, FIG. 1)
[Patent Document 2]
JP-A-8-192595 (columns 13-15, FIGS. 2, 5, 6)
[Patent Document 3]
JP 2000-233594 A (columns 24 to 26, FIGS. 1 and 2)
[0006]
[Problems to be solved by the invention]
Therefore, the present invention eliminates the above-mentioned conventional inconveniences, and since the sleeve is used for fixing the mechanism, when the set of the mechanism is inserted from the rear of the shaft cylinder, the locking piece of the sleeve is fixed. The purpose of this invention is to provide a mechanical pencil that can ignore the directionality because it is provided on the inner wall of the shaft cylinder and can be easily assembled, thereby making the internal structure of the shaft very simple. To do.
[0007]
Further, according to the present invention, the rear portion of the sleeve, with reliably perform the fixing to the shaft tube at a short distance because the fixing and syntan click guiding means of the shaft tube are formed, always lead tank An object of the present invention is to provide a mechanical pencil having a stable knock operation since the chuck spring works reliably because it can be held in the sleeve.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a mechanical pencil according to the present invention is a mechanical pencil comprising a shaft cylinder and a core feeding mechanism that is provided in the shaft cylinder and feeds a core in a core tank, and a sleeve constituting the core feeding mechanism. Is fixed to the shaft cylinder by the locking means.
[0009]
Further, the mechanical pencil of the present invention includes a shaft tube, a core tank that slides inside the shaft tube by operating means, a core feeding chuck that is directly or indirectly connected to the tip of the core tank, From a chuck ring loosely fitted to the chuck, a sleeve locked to the shaft cylinder by the locking means and provided with a chuck spring between the chuck, and a tip having a step portion with which the chuck ring abuts on the inner wall Become.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a mechanical pencil according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a rear end knock type mechanical pencil structure which is a mechanical pencil according to an embodiment of the present invention. In the figure, the shaft cylinder 1 includes a front shaft 2 and a rear shaft 3, and the front shaft 2 and the rear shaft 3 are configured to be detachable from each other by, for example, screwing or the like. A flange 21 having a step is provided on the outer periphery of the rear portion of the front shaft 2 between the front end surface of the rear shaft 3 and a rear end surface of a grip cover 14 described later.
[0011]
Further, a core tank 4 filled with a writing core is slidably provided inside the shaft cylinder 1. In the tip mounting portion of the lead tank 4, a writing lead feeding chuck 5 is press-fitted and fixed. A chuck ring 51 is loosely fitted on the chuck portion at the tip of the chuck 5. Further, a rear end portion of the lead tank 4 is formed with a large-diameter receiving portion 41 in which an eraser feeding mechanism described later is set. A locking protrusion 42 that locks to the rear shaft 3 is provided on the outer wall portion of the receiving portion 41.
[0012]
Further, a sleeve 6 having an inner flange 62 is provided outside the chuck 5 at a position slightly spaced from the tip. A chuck spring whose rear end is in contact with the lead tank 4 is mounted in the sleeve 6 and always urges the chuck 3 and the lead tank 4 backward. Further, a packing 8 for holding a writing core is provided in front of the chuck 3 so as to be slidable in a tip 9 attached to the shaft cylinder 1 by screwing.
[0013]
On the other hand, the way section after the lead tank 4, Eraser feeding mechanism is relatively non-rotatably attached to the shaft tube 1 with respect to the knock body 11 located at the end of the eraser mechanism The eraser is fed out by rotating the head of the knock middle shaft 10 that is relatively rotatable.
[0014]
In addition, the code | symbol 13 in the figure is the clip 13 provided with the O-ring-shaped attachment part 131. FIG. Further, the grip portion of the front shaft 2 is covered with a grip cover 14 that is usually made of rubber or soft synthetic resin.
[0015]
Next, the sleeve that is a feature of the present invention will be described in detail with reference to FIGS. The sleeve 6 is composed of a cylindrical main body 61, and an inner flange 62 (FIG. 4) is formed on the inner periphery slightly behind from the front end of the cylindrical main body 61. And it is made thin gradually from the base part of this inner flange 62 toward the front end edge, and the inclined surface 63 (FIG. 4) is formed. The inclined surface 63 makes the operation of the chuck ring 51 as a guide means smooth.
[0016]
On the other hand, at the rear end portion of the cylindrical main body 61 of the sleeve 6, the locking pieces are bent as four locking means that are bent outward at equal intervals of 90 ° and extended rearward from the rear end of the cylindrical main body 61. 64 is provided. A first inclined surface portion 65 extending radially outward from the base portion of these locking pieces 64 and a corner portion 67 via a flat portion 66 at the rear end of the first inclined surface portion 65. Is formed.
[0017]
Further, a second slope portion 68 is formed at the rear portion of the locking piece 64 and extends radially inward toward the rear. Further, the rear end of the second inclined surface portion 68 has a rear end surface 69 perpendicular to the axis. When the sleeve 6 is assembled into the front shaft 2, the locking piece 64 is bent inward to facilitate the assembly. Further, a holding piece 6b is formed between the split grooves 6a as holding means for holding and guiding the small-diameter tip portion of the core tank 4 slidably.
[0018]
Such mechanical pencil, core by inserting the rear or kidnapped catcher click spring 7 into the sleeve 6, then inserting the chuck 5 and the chuck ring 51 from the front, coupling the chuck 5 and the lead tank 4 at its rear end Assemble the feeding mechanism. Then, the core feeding mechanism can be assembled into the front shaft 2 from the rear and assembled by a simple operation of attaching the tip 8 and the rear shaft 3.
[0019]
In particular, the attachment of the sleeve 6 will be described. The inner flange 62 on the inner periphery of the front portion of the sleeve 6 serves as a stopper for receiving the chuck ring 51 and the large-diameter chuck portion formed at the front end of the chuck 5. Yes. On the other hand, the rear portion of the inner flange 62 plays a role of a stopper for receiving the tip of the chuck spline ring 7. Further, the rear portion of the sleeve 6 has four locking pieces 64, and these locking pieces 64 are in contact with and engaged with the annular rib 22 formed on the inner periphery of the front portion of the front shaft 2. It has been stopped. If the front portion of the annular rib 22 is an upright wall as shown in the drawing, the engagement with the corner portion 67 of the engagement piece 64 in the sleeve 6 is in surface contact, so that it is reliable.
[0020]
And since the front end surface of such a sleeve 6 is contact | abutted and latched to the internal peripheral step part 91 of the tip 9, the sleeve 6 is fixed between the tip 9 and the front shaft 2 after all. In particular, since the corner portion 67 is formed in the locking piece 64 of the sleeve 6, the corner portion 67 is locked to the annular rib 22 in the front shaft 2, and the sleeve 6 is securely fixed. . In such a state, the sleeve 6 always slidably holds and guides the tip of the lead tank 4 by the holding piece 6b, thereby enabling a smooth knocking action.
[0021]
The operation of the mechanical pencil according to the embodiment of the invention will be described below. First, when performing normal writing, when the rear end of the knock body 10 is knocked, the lead tank 4 is advanced against the chuck spring 7. Therefore, the chuck 5 connected to the lead tank 4 is also advanced. During the advancement process of the chuck 5, the chuck ring 51 loosely fitted to the chuck 5 comes into contact with the engaging portion of the inner wall of the tip 9 and comes off from the chuck 5, and the chuck 5 is released. As a result, the writing core is dropped and moved forward by its own weight.
[0022]
When the knocking is finished, the chuck 5 is retracted by the biasing force of the chuck spring 7. In this retreating process, the chuck ring 51 is fitted into the chuck 5 and the chuck 5 is closed, so that the writing core is held and writing is possible.
[0023]
Further, when the lead in the lead tank 4 runs out, the eraser feeding mechanism unitized from the shaft cylinder 1 can be removed, and the writing lead can be easily loaded into the lead tank 4. If necessary, the eraser can be easily fed out from the rear end of the mechanical pencil by a rotating operation.
[0024]
In addition, although the mechanical pencil by embodiment of the said invention demonstrated the thing of a rear end knock type, this invention is applicable also to a side knock type etc., and the form of a knock is not ask | required. Further, the present invention can also be applied to a case where the core tank is directly knocked without using the eraser feeding mechanism.
[0025]
【The invention's effect】
Since the present invention is configured as described above, since the sleeve is for fixing the mechanism, when the mechanism set is inserted from the rear side of the shaft cylinder, the directionality can be ignored and can be easily incorporated. There is an effect that the internal structure of the shaft can be created very easily.
[0026]
Further, according to the present invention, since the locking portion of the shaft tube and the core tank pressing piece are formed at the rear portion of the sleeve , the sleeve member with a short distance (length) can be securely fixed to the shaft tube. The In other words, by securing a portion that does not increase the inner diameter between a plurality of locking pieces of the shaft cylinder provided behind the sleeve, the chuck, chuck retaining spring, core tank, etc. mounted in the sleeve are held. Can have. Therefore, the knocking operation can be stabilized with a short sleeve member without extending the entire length of the sleeve member. Furthermore, since the lead tank can be held in the sleeve at all times, the chuck spring works reliably, so that the knock operation is stabilized.
[0027]
Furthermore, according to the present invention, since the sleeve has the locking piece , the attachment position of the core holding mechanism with respect to the shaft cylinder has an effect of not affecting the core feed amount.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a mechanical pencil according to an embodiment of the present invention.
FIG. 2 is a front view of the mechanical pencil of FIG.
FIG. 3 is an enlarged front view of the mechanical pencil sleeve of FIG. 1;
4 is a longitudinal sectional view of the sleeve of FIG. 3;
FIG. 5 is a bottom view of the sleeve of FIG. 3;
6 is a plan view of the sleeve of FIG. 3. FIG.
[Explanation of symbols]
1 Shaft cylinder 2 Front shaft 21 flange
22 annular rib 3 rear shaft 4 core tank 41 receiving part 42 locking protrusion 5 chuck 51 chuck ring 6 sleeve 61 cylindrical body 62 inner flange 63 inclined surface 64 locking piece (locking means)
65 First slope portion 66 Flat portion 67 Corner portion 68 Second slope portion 69 Rear end face 6a Split groove 6b Holding piece (holding means)
7 Chuck spring 8 Packing 9 Tip 91 Inner peripheral step 10 Knock center shaft 11 Knock body 111 Spiral groove 12 Slider 13 Clip 131 Mounting portion 14 Grip cover

Claims (3)

In the mechanical pencil comprising a shaft cylinder and a core feeding mechanism that is provided in the shaft cylinder and feeds the core in the core tank, and a sleeve constituting the core feeding mechanism is fixed to the shaft cylinder by a locking means. The sleeve is made of a cylindrical body, and an inner flange is formed on the inner circumference slightly behind from the front end of the cylindrical body. The inner end of the sleeve body of the sleeve is outwardly spaced at equal intervals. Is provided with a locking piece that is bent rearward and extends rearward from the rear end of the cylindrical body, and the locking piece extends from the base toward the rear in a radial outward direction, The first slope has a flat portion from the rear end toward the rear, and the rear end of the flat portion has a corner portion, and extends radially inward from the corner portion toward the rear. A second slope portion is formed, and the second slope portion is formed. End has a rear end face of the axis perpendicular, and the split groove on both sides of the locking piece is formed respectively, and provided with a circular rib which the locking member is locked to the barrel inner wall Mechanical pencil characterized by   2. The mechanical pencil according to claim 1, wherein the sleeve further includes a holding piece for slidably holding the core tank between the split grooves formed on both sides of the locking piece.   The mechanical pencil according to claim 2, further comprising an eraser feeding mechanism that also serves as a knock function at the rear of the lead tank.

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