JPH0745272B2 - Knock writing instrument including mechanical pencil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a knock-type writing instrument including a mechanical pencil body.
The present invention relates to an improvement in a knock-type writing instrument including a mechanical pencil body in which a large movement amount of a writing body can be obtained by a small pressing amount of a pressing member.

“Problems to be Solved by the Prior Art and the Present Invention” Conventionally, various knock-type writing instruments designed to obtain a large stroke of a writing body with a small pressing amount of a pressing member have been devised and have their own Although many of them are being put to practical use, many of them have a structure in which the engagement action of the cam surfaces of the cam members is the main element, and in this case, the surface contact operation of the cam surfaces is required. Therefore, it was difficult to expect smooth operation due to the frictional resistance between the two.

Further, when the cursive body to be accommodated includes a mechanical pencil body, not only the mechanical movement of the mechanical pencil body itself but also the lead core feeding operation is realized by the pressing action of the pressing member. Consideration of points is an essential issue. In other words, it is a major issue to solve the malfunction of the operation due to the frictional resistance between the cam surfaces and to realize the smoothness of the lead core feeding operation.

"Means for Solving Problems" The present invention is intended to improve the state of the art, and as described in the claims, a fixed guide cam surface provided in the inner cylindrical member. In contrast, the cam surface of the slide cam member that is inclined in the direction opposite to the direction of inclination of the cam surface and that interlocks with the writing body is positioned in an intersecting manner, and the shaft is provided at the end of the guide cam surface of the inner tubular member. A means for solving the problem is formed by forming a slit groove extending in the axial direction and further arranging the pressing cam portion of the pressing member in contact with both contact portions.

[Operation] According to the present invention, the pressing cam portion of the pressing member moves along the guide cam surface, and also moves the cam surface of the slide cam member inclined in the direction opposite to the guide cam surface. The amount of movement in the axial direction of the cam surface of the slide cam member naturally becomes larger than the amount of movement of the pressing cam portion of the pressing member, and the writing material interlocked with this slide cam member presses the pressing member to a smaller amount. It is possible to obtain a large stroke by the amount, and the lead core of the mechanical pencil body can be extended very smoothly by the pressing cam part moving in the slit groove provided at the end of the guide cam surface. To do.

[Examples] Examples of the present invention will be described below with reference to the drawings.

The inner cylinder member 2 mounted in the shaft cylinder 1 has a guide cam surface 2a of a pressing cam portion interlocking with the pressing member formed at the end on the side of the rear end opening 1b of the shaft cylinder, and its inner wall. A long groove 2b extending in the axial direction is formed at. Further, the inner cylinder member 2 is formed with a slit groove 2c extending in the axial direction at the end of the guide cam surface 2a. Reference numeral 3 denotes a slide cam member which has a protruding portion 3b which engages with the long groove 2b of the inner cylinder member 2 and which has a cam surface 3a inclined in a direction opposite to the guide cam surface 2a of the inner cylinder member 2. Further, a pendulum 4 for selecting a writing body and transmitting the pressing force of the pressing member 5 to the writing body is provided at the end opposite to the cam surface 3a. The pendulum 4 moves in accordance with gravity, so that it is easy to face the desired cursive body. The cursive body is a mechanical pencil body H and another cursive body B. Here, a ballpoint pen body is accommodated as the other cursive body B.

As shown in FIG. 2, the mechanical pencil body H has a known structure, and the lead core 13 is fed out by the opening / closing operation of the chuck portion 12 provided integrally with the lead core housing tube 11.

The cam surface 3a of the slide cam member 3 which is housed in the inner cylinder member 2 by engaging the protrusion 3b in the long groove 2b is inclined in the opposite direction to the guide cam surface 2a of the inner cylinder member. As described above, it is important that the cam surface 3a of the slide cam member and the guide cam surface 2a of the inner cylinder member are always in a crossed positional relationship. The inclination angles of the cam surfaces 2a and 3a are preferably set to about 45 degrees, so that as described later in detail, the slide cam member is pressed against the pressing stroke of the pressing member 5. The movement amount is almost doubled, and the smoothness of the operation can be obtained.

Reference numeral 6 is a guide cam surface 2a of the inner cylinder member in the intersecting state.
And the cam portion 3a of the slide cam member, which is in contact with the contact portion P with the cam surface 3a, receives the pushing force of the pushing member 5 protruding from the rear end opening portion 1b of the shaft cylinder, and receives the guide cam surface 2a. Along with the movement, the cam surface 3a of the slide cam member is also moved to move the slide cam member 3 in the inner cylinder member 2 toward the shaft cylinder front end opening 1a. Here, the pressing member 5 and the pressing cam portion 6 are separate bodies, but this has the advantage that the pressing member 5 does not receive the rotational force of the pressing cam portion 6 directly when pressing the pressing member 5. Of course, both may be integrated.

The pushing member 5 always has a built-in pin 7 that springs upward in a direction perpendicular to its axial direction via a coil spring S3. When the writing state is obtained via the pendulum 4, the protrusion projects from the long hole 8 of a predetermined length formed in the barrel 1 to counter the writing pressure in the writing state. Reference numeral 9 denotes a knob member facing the pin 7 projecting from the elongated hole 8, which is exposed from the clip C and is attached in a loose fit shape.

When this knob member 9 that is always located on the pin 7 is pushed toward the center of the barrel 1, the pin 7 is retracted into the barrel 1 and the pushing force of the coil spring S1 causes the pushing member 5 to return.
The cursive body exposed from the barrel 1 is also restored at the same time.

In the figure, 14 is an eraser fitted to the pushing member 5, and 15 is a cover member for protecting the eraser 14. As described above, the locking structure of the writing bodies H and B is realized here by the engagement relationship between the pushing member 5 and the barrel 1, but it goes without saying that other structures may be adopted, for example. A known rotary cam member (not shown) provided with a cam surface (not shown) on the inner wall of the inner cylinder member 2 is engaged with the protrusion 3b of the slide cam member 3 to interlock with and disengage from the cam surface. No.) may be used.

FIG. 1 is a schematic explanatory view of a writing instrument embodying the present invention. A mechanical pencil body H facing a pendulum 4 provided on a slide cam member 3 and another writing body B, for example,
The ball-point pen body is accommodated in the barrel 1 by being urged toward the rear end opening 1b of the barrel by the elastic force of the coil spring S2. As described above, S1 is a coil spring that repels the slide cam member 3 in the direction of the rear end opening 1b of the shaft cylinder, and the repulsive force extends to the pushing member 5, but the pushing member 5
The stepped portion 5a formed on the above contacts the collar portion 1b 'of the rear end opening portion 1b of the shaft cylinder to prevent each member from being separated from the rear end opening portion 1b of the shaft cylinder.

Next, the operation of the present invention will be described based on the development view of FIG.

In order to obtain a writing state of a desired cursive body, for example, a mechanical pencil body H, the pendulum 4 is made to face the mechanical pencil body H and the pressing member 5, that is, the eraser cover member 15 is repulsed by the coil spring S1. When pressed against a force, the pressing cam portion 6 interlocked with this is composed of a guide cam surface 2a provided on the inner cylinder member 2 fixed in the shaft cylinder 1 and a cam surface 3a provided on the slide cam member 3. At the intersection, that is, from the contact point P, the cam surfaces 2a and 3a of the two are moved in the direction of the arrow while simultaneously contacting each other, but the guide cam surface 2a of the inner cylinder member is fixed and the protruding portion 3b of the slide cam member is fixed. Is in the long groove 2b of the inner cylinder member, the pressing cam portion 6 inevitably pushes up the slide cam member 3 in the axial direction thereof toward the shaft cylinder front end opening portion 1a (arrow direction). At this time,
If the inclination angles of the cam surfaces 2a and 3a are set to about 45 degrees, smoother operation can be obtained and the slide cam member 3 can move with respect to the moving amount 1 of the pressing cam portion 6. As described above, the amount L generally doubles.

The inclination angle of the guide cam surface 2a of the inner cylinder member is made gentler than 45 degrees (obtuse angle) and the cam surface 3a of the slide cam member is formed.
If the inclination angle of the guide cam surface 2a is made steeper (acute angle), the amount of movement of the slide cam member 3 is more than twice the amount of movement of the pressing cam portion 6 in the axial direction. is there. With the movement of the slide cam member 3 in the axial direction, the pendulum 4 provided on the slide cam member 3 comes into contact with the mechanical pencil body H and is exposed from the front end opening 1a of the barrel.

When the mechanical pencil body H is exposed from the front end opening 1a of the barrel, the pin 7 of the pushing member projects from the long hole 8 of the barrel to secure the writing state.

When the pin 7 of the pushing member projects from the long hole 8 of the shaft cylinder, the pushing cam portion 6 interlocking with the pushing member 5 is positioned above the slit groove 2c provided at the end portion of the guide cam surface 2a of the inner tubular member. Therefore, if it is desired to feed the lead core 13 of the mechanical pencil body H after obtaining the writing state, the pushing member 5 may be further pushed in that state.

By pushing the pushing member 5, the pushing cam portion 6 moves in the slit groove 2c of the guide cam surface 2a, and the lead core of the mechanical pencil body is accommodated by the movement amount of the slide cam member 3. Press the tube 11. At this time, it goes without saying that the pin 7 of the pushing member moves within the elongated hole 8 of the shaft cylinder by the movement amount of the pressing cam portion 6.

The chuck portion 12 is opened and closed to move the lead core 13 by the forward and backward movement of the lead core housing tube 11 in the axial direction, but only the lead core housing tube 11 moves when the mechanical pencil H is in the writing state. When obtained, the step portion of the outer cylinder 10 of the mechanical pencil body
This is because the outer cylinder 10 is fixed by the contact of the front end step portion 1a 'with the shaft cylinder 10a. The lead core housing pipe 11 is housed in the outer cylinder 10 via the coil spring S4. To release the writing state, the knob member 9 loosely fitted to the clip C may be pressed toward the central portion of the shaft cylinder 1, whereby the pin 7 of the pressing member is retracted into the shaft cylinder 1. Then, the mechanical pencil body H is restored together with the pushing member 5 by the elastic force of the two coil springs S1 and S2.

The other strokes of the cursive body B can be moved in and out by a similar operation to obtain a large stroke of the cursive body B with a small pressing amount of the pressing member 5, but the pressing cam portion 6 moves the slit groove 2c of the guide cam surface 2a. Of course, there is no need to move.

[Advantages of the Invention] According to the present invention, as described above, the cam surface inclined in the opposite direction to the guide cam surface provided on the inner cylinder member is fixed in the inner cylinder member fixedly attached to the shaft cylinder in a cross shape. While accommodating a slide cam member that is tight and movable only in the axial direction, a slit groove is formed at the terminal end of the guide cam surface, and a pressing cam portion that interlocks with the pressing member is formed from the contact points of both. Since it is configured to move along the guide cam surface, the movement of the slide cam member having the cam surface inclined in the opposite direction to the guide cam surface is always larger than the movement amount of the pushing member, and a large stroke is obtained. Therefore, the writing body that interlocks with the slide cam member via the pendulum has a simple structure and can obtain the same amount of movement as the slide cam member while maintaining smooth operability.
Further, since the lead core feeding operation in the writing state of the mechanical pencil body can be performed by moving the pressing cam portion interlocking with the pressing member in the slit groove, the operation can be performed extremely smoothly. It was

[Brief description of drawings]

FIG. 1 is a partially omitted vertical cross-sectional view for explaining a knock-type writing instrument including a mechanical pencil body according to the present invention, FIG. 2 is an explanatory diagram for the mechanical pencil body, and FIG. 3 is a main component of the present invention. FIG. 4 is an exploded perspective view illustrating the operation, and FIG. 4 is an exploded perspective view illustrating the positional relationship among the main constituent elements of the present invention. DESCRIPTION OF SYMBOLS 1 ... Shaft cylinder, 2 ... Inner cylinder member, 2a ... Guide cam surface, 2b ... Long groove, 2c ... Slit groove, 3 ... Slide cam member, 3a ... Cam surface, 3b ... Projection part, 4 ... Pendulum, 5 ... Pushing member, 6 ... Pushing cam portion, 7 ... Pin, 8 ... Long hole, 9 ... Knob member, S1, S2,
S3, S4 ... Coil spring, H ... Mechanical pencil,
B ... Ballpoint pen body.

Claims (2)

[Claims] 1. A knock type writing instrument having a writing body retracting mechanism for retracting a writing end of a writing body from a front end opening of a shaft cylinder by a pressing action of a pushing member protruding from a rear end opening of the shaft cylinder. An inner cylinder member 2 having a long groove 2b extending in the axial direction and having a guide cam surface 2a formed at the end on the side of the shaft cylinder rear end opening 1b is mounted. A slide cam member 3 having a cam surface 3a inclined in the opposite direction to the guide cam surface 2a and provided with a protruding portion 3b engaging in the long groove 2b and a pendulum 4 driven by gravity is provided.
3a is biased and housed in the direction of the rear end opening 1b of the barrel so that the guide cam surface 2a is located in a crossed manner, and further extends in the axial direction at the end of the guide cam surface 2a. A pressing cam portion 6 is formed in the inner tubular member 2 while forming the slit groove 2c and abutting against a contact portion P between the guide cam surface 2a of the inner tubular member and the cam surface 3a of the slide cam member. A mechanical pencil body that is mounted so as to interlock with the pendulum 4 and that accommodates a mechanical pencil body H and other cursive body B that are urged toward the rear end opening portion 1b of the shaft cylinder facing the pendulum 4. A knock-type writing instrument including. 2. A guide cam surface 2a of an inner cylinder member and a cam surface 3a of a slide cam member, which are inclined in mutually opposite directions, are set to have an inclination angle of about 45 degrees. A knock-type writing instrument including the mechanical pencil described in the item.