JPH0453992Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention separates the barrel into an upper barrel and a lower barrel, and uses the relative rotation of the two to enable multiple writing devices housed within the barrel. The present invention relates to an improvement of a writing instrument equipped with a so-called rotary writing body ejection and retraction mechanism in which the body alternately appears and retracts from the lower end opening of the barrel.

"Problems to be solved by the prior art and the present proposal" Conventionally, the shaft cylinder is separated into an upper shaft cylinder and a lower shaft cylinder, and by the relative rotational operation of the two,
Many of the devices in which a plurality of cursive letters housed in a barrel are made to alternately appear and disappear from the opening of the barrel have a basic structure based on the invention disclosed in Utility Model Publication No. 52-40833. . In other words, a cam member consisting of two inclined surfaces of approximately equal length from the center is installed in the upper shaft cylinder by some means, and the cam surfaces of this cam member and the respective cam surfaces are directed toward the upper end of the shaft cylinder. A writing body that is biased and engaged is housed in a sliding case so as to be movable only in the axial direction, and the sliding case is movably mounted inside a cam member.

In this case, if the central part of the cam member is made into a notch-like locking part and the sliding case is made to operate integrally with the lower shaft cylinder, the rotational operation of the lower shaft cylinder or the upper shaft cylinder will cause A writing state or a released state is obtained by alternately engaging and disengaging the writing body that engages with the cam surface of the cam member with the locking portion of the cam member against the biasing force.

However, even with this relatively reasonable approach, there are some problems. First, since the cam member is a separate and independent entity, it is complicated in that consideration must be given to the mounting structure of the cam member to the upper shaft cylinder. Furthermore, even with the mounting structure of the sliding case that is movably mounted within the cam member, it is not so easy to prevent it from coming off the cam member while ensuring its movability.

``Means to solve the problem'' This proposal not only increases the number of parts, but also complicates the workability in the assembly process, which ultimately leads to an increase in costs. The invention is intended to improve a writing instrument equipped with a writing instrument, in which a cam portion having a cam surface with which a writing body engages is formed on the inner wall surface of the upper barrel, and
An annular recess is formed in the sliding case that accommodates the writing body so as to be movable only in the axial direction and is fitted into the upper shaft cylinder by engaging the cam part, and furthermore, the connecting part of the sliding case is formed in the annular recess. is formed into a small diameter irregularly shaped part, and has the same shape as this irregularly shaped connecting part, and
A ring member having a through hole with an inner circumferential diameter larger than the outer diameter and a bent part that engages with the annular recess of the sliding case is connected between the end face of the bent part and the lower shaft cylinder. A means to solve this problem is to fix it to the upper barrel so that a gap is created between it and the end face.

"Operation" According to the present invention, a bent part of the ring member having a larger diameter than the cross-section of the sliding case is formed in the annular recess of the sliding case to create a gap between the end face of the bent part and the end face of the lower shaft cylinder. Furthermore, since the ring member is fixed to the upper barrel, the sliding case containing the writing body that engages with the cam surface on the inner wall of the upper barrel can be easily prevented from detaching from the upper barrel. At the same time, the rotational operation of the sliding case can be maintained reliably, and furthermore, the outer diameter of the engaging portion of the sliding case with the shaft cylinder can be formed to be constant over the entire length in the axial direction. Therefore, even when trying to keep the shaft cylinder itself as slender as possible and also leave as much room as possible in the inner diameter of the upper shaft cylinder, the diameter of the sliding case can be uniformly reduced, so the wall thickness of the upper shaft cylinder can be reduced by a considerable amount. This means that it can be maintained thickly,
It becomes possible to select a more reliable means for fixing the ring member.

"Example" Hereinafter, an example of the present invention will be described based on the drawings.

The barrel 1 is separated into an upper barrel 1a and a lower barrel 1b, and a cam portion 2 for projecting and retracting a writing body is formed on the inner wall surface of the upper barrel 1a. This cam part 2 has a cam surface 2 consisting of inclined surfaces of approximately equal length on both sides with a notch-shaped cursive locking part 2c provided in the center as the center.
It has a and 2b. As described later, a plurality of writing bodies 4 and 5 housed in the sliding case 3 engage with the cam surfaces 2a and 2b.

The writing bodies 4 and 5 housed in the sliding case 3 are urged toward the upper end 1c of the shaft cylinder and are movable only in the axial direction, and an example of their specific structure is as follows. be.

The cursive letters 4 and 5 are provided in the sliding case 3 through a slit portion 6 extending in the axial direction, which is bored in the sliding case 3.
The sliding parts 4a and 5a of the writing body that engage with the cam surfaces 2a and 2b of the cam part 2 are exposed from a and 6b, and the elastic force of the coil springs 7a and 8a always moves the cursive body toward the upper end 1c of the shaft cylinder. It is energized and accommodated. An annular recess 3a is formed in the sliding case 3, and a portion below the recess 3a serves as a connecting portion 3b with the lower shaft cylinder 1b. Sliding case 3
The connection between the connecting portion 3b and the lower shaft cylinder 1b is
It is important that b and 1b can be operated in unison, and the specific means for doing so may be determined as appropriate. Here, a screw-fitting structure is used, but this method is advantageous in that it is relatively easy to separate both 3b and 1b, and the writing bodies 4 and 5 can be easily replaced. .

In addition, in the case of a screw fitting structure, the length adjustment of the screw thread and the cam surface 2a of the cam portion where the writing bodies 4 and 5 engage,
If consideration is given to setting the inclination angle of 2b, the lower shaft cylinder 1b
It has been confirmed through operation experiments during the prototyping process that there is no problem with the alternating appearance and reappearance of the writing fonts 4 and 5 due to the rotating operation. Connecting portion 3b of sliding case 3
The cross-sectional shape in the direction perpendicular to the axial direction is formed into an irregularly shaped part having a small diameter part with respect to the annular recess 3a of the sliding case 3, but here the irregularly shaped part is made into a substantially elliptical shape. There is. The bent portion 9a of the ring member 9 has a through hole portion 10 having the same shape as the irregularly shaped connecting portion 3b of the sliding case 3 and having an inner diameter larger than the outer diameter of the connecting portion 3b. It is inserted into the annular recess 3a of the sliding case 3 through the through hole 10. The bent portion 9a of the ring member 9 that has reached the annular recess 3a of the sliding case 3 bends the abutment portion 9b, which has a larger diameter than the through hole portion 10, into an annular shape by rotating in any direction in the circumferential direction. It can be engaged with the recess 3a.

The bent portion 9a of the ring member 9 that has engaged with the annular recess 3a naturally comes into contact with the sliding case 3, and in this state, the ring member 9 is in contact with the upper shaft cylinder 1.
a by an appropriate means.

The ring member 9 engages its bent portion 9a with the annular recess 3a of the sliding case 3, so that the sliding case 3
Since separation from the upper barrel 1a is prevented, the outer diameter of the engaging portion 3c of the sliding case 3 with the barrel 1 can be made constant over its entire length in the axial direction. Even if the shaft cylinder 1 itself is kept as slender as possible and the inner diameter of the upper shaft cylinder 1a is made to have as much room as possible, the sliding case 3
Since the outer diameter of the upper shaft cylinder 1a can be uniformly reduced, the wall thickness of the upper shaft cylinder 1a can be maintained at a considerable thickness.

Therefore, it is possible to select a more reliable and simple fixing structure for fixing the ring member 9 to the upper shaft cylinder 1a. Furthermore, it is also possible to adopt a fixing structure by screw fitting using an adhesive as a medium.

It is important that the connecting portion 3b of the sliding case 3 and the lower shaft cylinder 1b be connected by appropriate means so that both 3b, 1b can operate together, and both 3b, 1b are preferably connected. As mentioned above, the two should be separably connected, but the point to note in the connection structure of both 3b and 1b is that when both 3b and 1b are connected, the lower shaft cylinder 1
This means that a gap S must be formed between the end surface 1b' of the ring member 9 and the end surface 9a' of the bent portion 9a of the ring member 9.

The ring member 9, which is fixed to the upper shaft cylinder 1a due to the existence of this gap S, engages its bent part 9a with the annular recess 3a of the sliding case, and the sliding case 3 is separated from the upper shaft cylinder 1a. In addition, the rotational operation of the sliding case 3, that is, the rotational operation of the lower shaft cylinder 1b is guaranteed. Note that C in the figure is a clip piece attached to the upper end portion 1c of the shaft cylinder.

"Effect of the invention" As described above, the present invention forms an annular recess in the sliding case whose outer diameter is uniform at the engaging part with the shaft cylinder over the entire length in the axial direction, and in this sliding case, Since the ring member is fixed to the upper shaft cylinder by engaging the bending part with the recess of the sliding case, the bending part of the ring member and Since engagement with the sliding case can be obtained, it is easy to prevent the sliding case from separating from the upper shaft cylinder.In addition, the shaft cylinder itself can be made as slim as possible, and the inner diameter of the upper shaft cylinder can have as much margin as possible. Even if the outer diameter of the sliding case can be reduced uniformly, the wall thickness of the upper shaft cylinder can be maintained at a considerable thickness. Therefore, it has become possible to select a more reliable and simple fixing structure for fixing the ring member and the upper shaft cylinder.

Further, according to the present invention, since the ring member that prevents the sliding case from coming off the upper barrel is fixed to the upper barrel, it serves as a decorative ring to improve the aesthetic appearance of the writing instrument exterior. Furthermore, since the writing body ejecting cam portion may be formed directly on the inner wall surface of the upper barrel, a writing instrument with a simple structure and a reliable rotary writing body ejecting mechanism can be obtained very easily. Summer.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the entire writing instrument according to the present invention, Fig. 2 is a cross-sectional explanatory view showing the relationship between the cam part in the upper barrel and the sliding case, and Fig. 3 is Fig. 1A. Fig. 4 is a front view of the ring member, Fig. 5 is a partial cross-sectional front view showing the outer circumference of the sliding case connecting part, and Fig. 6 is an engagement between the ring member and the sliding case. A partially sectional front view illustrating the state. DESCRIPTION OF SYMBOLS 1... Shaft cylinder, 1a... Upper shaft cylinder, 1b... Lower shaft cylinder, 2... Cam part, 2a, 2b... Cam surface, 3
...Sliding case, 3a...Annular recess, 4, 5...
Cursive, 4a, 5a... Sliding part of cursive, 7a,
8a...Coil spring, 9...Ring member,
9a...Bending part, 9b...Abutting part, 10...Through hole part.

Claims (1)

[Scope of utility model registration request] The barrel is separated into an upper barrel and a lower barrel, and a plurality of writing fonts are urged toward the upper end of the barrel by the relative rotation of the two, and alternately appear and retract from the opening at the lower end of the lower barrel. In this writing instrument, a cam portion 2 for protruding and retracting a writing body formed on the inner wall surface of the upper barrel 1a.
The writing bodies 4 and 5 that engage with the cam surfaces 2a and 2b are housed in a sliding case 3 that operates integrally through the lower shaft cylinder 1b and the connecting portion 3b so as to be movable only in the axial direction thereof, An annular recess 3a is formed on the outer circumferential surface of the sliding case 3, and the connecting portion 3b of the sliding case 3 is formed into a small diameter irregularly shaped portion with respect to the annular recess 3a, and has the same shape as the irregularly shaped connecting portion 3b. The annular recess 3a of the sliding case 3 has a through hole 10 with an inner circumferential diameter larger than its outer diameter.
The ring member 9 formed with a bent portion 9a that engages with the upper shaft tube 1a is inserted into the upper shaft tube 1a so that a gap S is formed between the end surface 9a' of the bent portion 9a and the end surface 1b' of the lower shaft tube 1b. A writing instrument equipped with a rotating writing mechanism that is fixed to a rotating writing body.