JP3757395B2 - Writing instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a writing instrument in which a refill is projected and retracted from a tip end of a shaft cylinder by a rotating cam mechanism, and particularly relates to a writing instrument in which the rotating cam mechanism can be easily and reliably incorporated into a shaft cylinder.
[0002]
[Prior art]
The rotating cam mechanism of the writing instrument is composed of a normal outer cam, as shown in Japanese Utility Model Publication Nos. 63-37270, 64-17790, Japanese Utility Model 4-89391, Japanese Utility Model 4-23028, Japanese Utility Model 7-45355 and others. It consists of a rotating cam and a knock cam. The outer cam has a longitudinal groove arranged in an annular shape and is fixedly provided in the shaft cylinder, and the rotating cam is formed at a protrusion engaging with the longitudinal groove of the outer cam and at the tip of the longitudinal groove of the outer cam. The knock cam has a cam surface that engages with the cam surface and is rotatably provided. The knock cam has a projection that engages with the longitudinal groove of the outer cam and a cam surface that engages with the cam surface of the rotary cam. It is provided to be movable. Then, as is well known, when the refill is urged rearward by an elastic member and the knock cam is advanced in the axial direction against the elastic member, the rotating cam rotates and alternates between a forward position and a backward position. The refill provided in front of the rotary cam moves, and thus the writing tip protrudes from the base provided at the tip of the shaft tube or is immersed in the base.
[0003]
The rotary cam mechanism is generally configured as described above. However, the inner surface of the cam housing is provided separately from the shaft cylinder so that the outer cam is fixedly formed in the shaft cylinder. Various configurations are known in which an outer cam is formed on the inner cylinder and the cam housing is inserted into the shaft tube and fixed. Conventionally, in order to fix such a cam housing body in the shaft tube, a recess is provided in the shaft tube by an undercut so that the housing body can be engaged, screwed, press-fitted, or metal parts. Or press fit.
[0004]
However, indentations, screwing, press-fitting, and the like due to undercuts as described above tend to cause problems such as whitening and cracking, and the assembly work is often troublesome.
[0005]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a writing instrument in which the rotating cam mechanism as described above can be easily and reliably provided in the shaft cylinder.
[0006]
[Means for Solving the Problems]
According to the present invention, in a writing instrument in which a refill is caused to appear and disappear by a rotating cam mechanism including an outer cam, a rotating cam that rotates in the outer cam, and a knock cam that moves the rotating cam in the axial direction, A cam set incorporating a rotating cam and a knock cam is provided, and a claw piece is formed on the peripheral surface of the inner body that houses the cam set so as to be swingable. A hooking portion that can be protruded is provided, an outer body is attached to the outside of the inner main body, the claw piece is pressed inward, and the cam set is moved into the inner main body by the hooking portion protruding inward. The writing instrument characterized by having been fixed is provided, and the said subject is solved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Various structures have conventionally been proposed as specific configurations of the rotating cam mechanism. As described above, the rotating cam mechanism basically includes an outer cam, a rotating cam, and a knock cam. One example is shown in FIG. Has been. In the figure, an outer cam (1) is formed in a cam housing (3) provided with a shoulder portion on the outer periphery and having this as a locking portion (2), and vertical grooves (4) having different depths are annularly formed. The cam surface (5) is formed in the front part of this vertical groove (4). The rotating cam (6) has a protrusion (7) that engages with the longitudinal groove (4) and a cam surface (8) that engages with the cam surface (5) when moved to the forward position. The cam housing (3) is rotatably inserted. The knock cam (9) has a protrusion (10) that engages with the longitudinal groove (4), and a cam surface (11) that engages with the cam surface (8) of the rotating cam (6) at the tip. Have.
[0008]
The rotating cam (6) and the knock cam (9) are assembled into the storage body from the front of the cam storage body (3) to form a cam set (12). At this time, an appropriate protrusion (not shown) can be formed in the storage body so that the rotating cam (6) and the like do not easily come out forward, and the knock cam protrudes rearward from the cam storage body (3). As shown in FIG. 3, a knock (13) is fitted to the shaft portion of (9) by press fitting or the like.
[0009]
The inner body (14) for housing the cam set (12) is made of a plastic material or a metal material, and is formed in a cylindrical shape slightly longer than the outer body (15) in FIG. A substantially U-shaped cut groove (16) is formed in the upper and lower ends, and one or a plurality of claw pieces (17) are provided so as to be elastically swingable. At the tip of the claw piece (17) is formed a raised portion (18) that slightly protrudes outward from the circumferential surface of the middle main body, and a latching portion (19) that can project into the middle main body is provided on the inner side. It has been. Further, an inner protrusion such as a rib (20) is formed on the inner surface of the inner body (14), screws (21) and (22) are provided at the front end and the rear end, and a large diameter portion ( 23) is provided.
[0010]
The outer body (15) is made of a plastic material, an elastomer material, a metal material, a wood material, etc., has an inner diameter substantially inscribed on the outer periphery of the middle body (14), and has a screw (24) provided on the rear part. Although it is connected to the middle main body (14) by screwing to the screw (22), it can also be connected by press fitting, uneven engagement or other appropriate connecting means.
[0011]
Thus, to assemble the writing instrument, first, the outer cam (1), the rotating cam (6) and the knock cam (9) are assembled to form a cam set (12), and the knock (13) is placed at the rear of the knock cam. Fit. Next, the cam set (12) is inserted into the middle main body from the rear side of the middle main body (14), and the tip is brought into contact with an inward projection such as the rib (20). Then, when the outer main body (15) is covered from the front of the middle main body (14) and connected to the middle main body, the claw piece (17) protrudes inward and the hooking portion (19) becomes the cam housing (3 The cam set (12) is fixed in the inner main body (14). Thereafter, a refill (26) such as a ballpoint pen refill fitted with a spring (25) may be inserted into the middle main body (14), and the base (27) may be attached to the front end of the middle main body (14). The connection between the base (27) and the inner main body (14) is screwed in the embodiment shown in the figure, but may be connected by connecting means such as press-fitting and concave-convex engagement. Further, by attaching the base to the middle body, the outer body (15) is clamped and fixed between the mouthpiece (27) and the large diameter portion (23) of the middle body (14), and the screws (22), ( 24) may be omitted.
[0012]
In the above embodiment, the latching portion (19) of the claw piece (17) is engaged with the latching portion (2) of the cam housing (3), but the latching portion has various shapes, The cam set can be fixed by providing a concave / convex groove on the peripheral surface of the storage body (3) to engage the latching portion, or by providing a vertical groove into which the latching portion enters. It is also possible to prevent rotation (not shown).
[0013]
In the above embodiment, the outer main body is covered over almost the entire length of the inner main body. However, the outer main body may be covered only on the rear part from the portion corresponding to the outer periphery of the inner main body provided with the claw pieces. . In this case, for example, as shown in FIG. 5, a step portion (28) is formed in the middle main body (14), and the outer main body (15) is moved from the rear of the middle main body (14) until it hits the step portion (28). What is necessary is just to insert and connect with a middle main body by uneven | corrugated engagement (29), screw engagement, etc.
[0014]
【The invention's effect】
The present invention is configured as described above, and an outer cam, a rotating cam and a knock cam are incorporated to form a cam set, the cam set is inserted into the inner body, and the inner body is covered with the outer body. since so as to fix the pawl provided with the cam set to move to the intermediate body inwardly, middle and outer body regardless of the undercut and pressed method as the method of fixing the conventional rotating cam mechanism The cam set can be fixed easily and reliably simply by covering the main body, there is no risk of inconvenience such as whitening or cracking, and the assembly is easy and economical.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a cam set portion.
FIG. 3 is a half sectional view of the assembled state.
4A and 4B are enlarged views, and FIG. 4A is a front view of the rear portion of the middle main body, and FIG.
FIG. 5 is a half sectional view showing another embodiment.
[Explanation of symbols]
1 Outer cam 3 Cam housing 6 Rotating cam 9 Knock cam
12 Cam set
13 Knock
14 Middle body
15 Outer body
17 Nail pieces
27 base

Claims (3)

In a writing instrument in which a refill is projected and retracted by a rotating cam mechanism including an outer cam, a rotating cam that rotates within the outer cam, and a knock cam that moves the rotating cam in the axial direction, the outer cam is formed on the inner surface of the cam housing. pawl swingably circumferential surface of the body in which to provide a cam set to form the engagement portion on the outer periphery of the write-the cam receiving member assembled the rotating cam and knocking cam to the cam housing body, housing the cam set An inward projection is formed on the inner surface so as to contact the front end of the cam housing body, and a protruding portion protruding outward and a latching portion capable of protruding inward are provided at the tip of the claw piece, An outer body is mounted on the outer side of the middle body, the claw piece is pressed inward, the hooking portion protruding inward is locked to the locking portion, and the cam set is fixed in the middle body. Writing instrument characterized by having done.   The writing instrument according to claim 1, wherein the outer main body is sandwiched between a large-diameter portion formed at a rear end of the middle main body and a base attached to a front end of the middle main body.   The writing instrument according to claim 1, wherein the outer body is mounted rearward from a portion corresponding to the outer periphery of the nail piece of the middle body.

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