JPH0251399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a shutter mechanism provided at the tip of a main body of a plunge-and-retract type writing instrument.

[Technical background of the invention and its problems]

Conventionally, the shutter mechanism of plunge-activated writing instruments such as capless fountain pens was developed in 1973.
A structure such as that disclosed in Japanese Patent No. 6265 is known, but all conventional shutter mechanisms including this example have the disadvantage that the structure is complicated, and assembly is troublesome and costly. There was also the problem that it was not possible to achieve complete airtightness in a closed state.

[Purpose of the invention]

This invention was made in order to solve the above-mentioned drawbacks of the conventional art, and its purpose is to provide a plunge-activated writing instrument that has a simple structure, is easy to assemble, and has good airtightness when the lid is closed. The objective is to provide a shutter mechanism.

[Summary of the invention]

In order to achieve the above-mentioned object, the shutter mechanism of the present invention has a tip opening on the inside of the tip of the writing instrument body, the opening diameter of which is brought into close contact with the inner circumferential surface of the tip of the writing instrument body, and a tip opening that is in contact with the inner surface of the main body. The cylinder peripheral side wall part and the cylinder peripheral side wall part which is separated from the inner surface of the distal end of the main body and are inclined at an appropriate angle and intersect with the axis of movement of the writing end of the writing element body, and when the writing end of the writing element body is in the retracted state, writing can be performed. A thin, flexible cap-shaped elastically deformable lid is fitted, which is made up of a cylinder top end that is displaced laterally from the end position, and when the writing end moves forward, the writing end shoulder portion of the elastically deformable lid is fitted. The lid is opened by slidingly contacting the inclined cylinder circumferential side wall portion and deforming the elastically deformable lid into a crescent-shaped cross-sectional shape, and the crescent-shaped elastically deforming lid is resiliently restored by the recessing of the writing end. This feature is characterized in that the lid can be closed by.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings of FIGS. 1 to 6. This embodiment is a writing element body 3 that is operated so that a writing end 2 is protruded and recessed into a writing instrument body 1 from the tip of the body. In the plunge-and-retract type writing instrument incorporating the writing instrument, inside the tip of the writing instrument body 1,
A distal end opening 4 having an opening diameter that is tightly fitted to the distal inner circumferential surface 4a of the main body, a cylindrical circumferential side wall 5 that contacts the distal inner circumferential surface 5a of the main body 1, and a first As shown in the figure, the cylindrical peripheral side wall 6 is inclined at an appropriate angle α (for example, an angle of about 15 degrees) and intersects with the writing end protrusion/retraction movement axis S of the separate writing element 3, and the writing element 3 is A thin and flexible cap-shaped elastically deformable lid 8 is fitted, which consists of a cylinder top end 7 that is displaced laterally from the position of the writing end 2 when the end is retracted, as shown in FIGS. 1 and 2. , the writing end 2
When the writing end shoulder 2a moves forward, the writing end shoulder 2a elastically deforms when the lid 8 moves forward.
The elastically deformable lid 8 is in sliding contact with the inclined cylinder peripheral side wall 6.
The lid is opened by pressing and deforming it into a crescent-shaped cross-sectional shape as shown in FIG. In this embodiment, the elastically deformable lid 8 is a conical cylinder as shown in FIG. 5, which is integrally molded with a flexible elastic material. If the main body 1 is configured as a shaped body and is assembled by dropping it from the rear of the main body 1, or if the main body 1 has a tip having a lid storage space removably screwed onto the tip of a shaft cylinder, the above-mentioned It is assembled by inserting the tip from the opening end with the tip removed.

In addition, the reference numeral 9 shown in FIGS. 1 and 2 is a writing end movement guide piece fitted into the writing instrument main body 1, 10 is a spring that biases the writing element body 3 backward, and 11
is a seal gasket that moves within the main body 1 together with the writing element 3. In order to solve the problem of increase and decrease in internal pressure due to the pumping action of the gasket movement, a protrusion 1a for air release is provided in the main body 1. is provided.

FIG. 7 shows a modified example in which the elastically deformable lid 8 is configured by pressing and deforming the circumferential side wall of the top side of a flexible cylindrical body into a crescent-shaped cross-sectional shape, and bonding the deformed top side end to the inner surface. The same reference numerals are given to the corresponding parts of the conical cylindrical elastically deformable lid 8, and a detailed explanation of the structure will be omitted.

〔Effect of the invention〕

Since the shutter mechanism of the thrust-and-retract type writing instrument of the present invention has the above-mentioned cap-shaped elastically deformable lid fitted inside the tip of the writing instrument body, it has a smaller structure than the conventional fulcrum opening/closing type shutter mechanism. It is simple, easy to assemble, and provides good airtightness when the lid is closed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of essential parts of a plunge-and-retract action type writing instrument equipped with a shutter mechanism according to an embodiment of the present invention in a writing end retracted state (shutter lid closed state), and FIGS. Fig. 4 is a cross-sectional view of the - line and the - line part, and Fig. 4 is a writing state in which the writing end of the writing element protrudes toward the front of the main body (shutter lid open state).
FIG. 5 is a cross-sectional view of the - line portion in FIG. It is an explanatory diagram showing a different configuration aspect. DESCRIPTION OF SYMBOLS 1... Writing instrument body, 2... Writing end, 3... Writing element body, 4a... Inner peripheral surface portion on the tip side of main body, 4...
Tip opening of the elastically deformable lid, 5a...Inner side surface of the tip of the main body, 5...Cylinder peripheral side wall of the elastically deformable lid, S...
Axis of writing end protrusion and retraction movement, 6... Inclined cylindrical circumferential side wall of elastic deformation lid, α... Cylinder circumferential side wall inclination angle, 7...
Cylinder top end, 8...Elastically deformable lid.

Claims (1)

[Scope of Claims] 1. In an openable/closable shutter mechanism for closing an opening at the tip of a thrust-and-retract operating type writing instrument, which incorporates a writing instrument element in the writing instrument body that is operated so that the writing end protrudes from the tip of the main body. , on the inside of the tip of the writing instrument body, a tip opening with an opening diameter that is brought into close contact with the inner peripheral surface of the tip of the main body, a cylindrical side wall that contacts the inner surface of the tip of the main body, and from the inner surface of the tip of the main body. a cylindrical peripheral side wall that is inclined at an appropriate angle and intersects with the writing end protrusion/retraction movement axis of the separate writing element;
A thin and flexible hat-shaped elastically deformable lid consisting of a cylinder top end that is displaced laterally from the writing end position when the writing end of the writing element is retracted is fitted, and when the writing end moves forward, The writing end shoulder portion slides into contact with the inclined cylinder peripheral side wall portion of the elastically deformable lid, and the elastically deformable lid is opened by pressing and deforming it into a crescent-shaped cross-sectional shape;
Further, the shutter mechanism of the thrust-and-contraction type writing instrument is characterized in that the lid is closed by elastically restoring the crescent-shaped elastically deformed lid when the writing end is retracted. 2. The shutter mechanism for a plunge-and-retract type writing instrument according to claim 1, wherein the elastically deformable lid is a conical cylindrical body integrally molded from a flexible elastic material. 3. Claims characterized in that the elastically deformable lid is constructed by pressing and deforming the top peripheral side wall of a flexible cylindrical body into a crescent-shaped cross-sectional shape, and bonding the deformed top side end to the inner surface. A shutter mechanism of the plunge-and-retract operating type writing instrument according to item 1.