JPS59239Y2 - Shape pencil - Google Patents

Description

[Detailed description of the invention] This invention relates to a mechanical pencil that prevents the lead pipe from flying out during disassembly or assembly adjustment.

Conventionally, when the cap is removed due to core jamming, etc., or when the cap is inserted at the final stage of assembly, the core may be removed due to the elastic force of the spring inserted inside or the inclination of the outer cylinder during operation. The problem was that the pipes would pop out.

In particular, with mechanical pencils equipped with overpressure buffer springs, the spring always urges the lead pipe in the forward direction, so the lead pipe always pops out, which reduces work efficiency during assembly and adjustment. This was the cause of a significant decline.

This idea prevents the core pipe from popping out by forming a bulge on the core pipe that is latched to the latching portion of the cushion spring, and also drills a groove in the latching portion that corresponds to the bulge. It is an object of the present invention to provide a mechanical pencil in which the core pipe can be taken out as necessary, especially during assembly and adjustment.

An embodiment of this invention will be described below with reference to the drawings.

Figure 1 is a longitudinal cross-sectional view of the mechanical pencil according to this invention.
FIG. 2 is an enlarged cross-sectional view of the bulging portion, and FIGS. 3 and 4 are enlarged cross-sectional views of the locking portion.

The outer cylinder 1 has a cap 2 screwed onto its tip, a core pipe 3 housed inside so as to be movable in the axial direction, and an annular cushion spring member projecting inward from the inner wall. A locking portion 4 for locking is arranged.

The tip of the lead chuck 5 inserted into the tip of the core pipe 3 passes through the center hole of a chuck ring 6 with a U-shaped cross section that tightens the lead chuck 5. It faces the front end of the sleeve 7 which is axially movable within the sleeve 1 .

This sleeve 7 is urged forward in its moving direction by a cushion spring 8 inserted between a locking portion 4 for locking a cushion spring protruding from the outer cylinder 1, and The pipe 3 is urged in the backward direction by a knock spring 9 inserted between the pipe 3 and the sleeve 7.

Further, on the outer circumferential portion of the core pipe 3 located a little rearward from the locking portion 4 of the outer cylinder 1, there is a bulge extending outward to prevent the core pipe from popping out, as shown in FIGS. 1 and 2. A pair of 10 is formed.

This bulging portion 10 is easily formed by crushing the core pipe 3 at two places as shown in the second figure, and the position where the bulging portion 10 is formed is determined by the above-mentioned knocking operation. Any suitable position behind the locking portion 4 of the outer cylinder 1 may be used as long as it is within the range of movement of the core pipe 3 and within the range where there is no problem even if the tip of the core pipe 3 protrudes.

On the other hand, the locking portion 4 for locking the cushion spring may be connected to the through hole 11 of the core pipe 3 as shown in the third figure, or connected to the outer periphery of the through hole 11 as shown in the fourth figure. A pair of grooves 12 corresponding to the bulged portion 10 are bored in a part,
It is formed so that it can be extracted from the outer cylinder 1 only when the bulged portion 10 faces the position of the groove 12.

Therefore, the locking portion 4 of the outer cylinder 1 functions as a locking portion of the cushion spring 8 and also functions to prevent the core pipe 3 from popping out.

In the present invention, when the cap 2 is removed from the outer cylinder 1, the inclination of the outer cylinder 1 at the time of removal, especially the elastic force of the cushion spring 9 that biases the core pipe 10 in the forward direction via the sleeve 7. , the core pipe 3 tries to fly forward, but since the bulging part 10 of the core pipe 3 is locked by the locking part 4, the outer cylinder 1
There is no risk of it flying out.

Moreover, when it is desired to take out the core pipe 3 as necessary, the bulging part 10 of the core pipe 3 is inserted into the groove 1 of the outer cylinder 1.
After appropriately rotating the core pipe 3 to a position opposite to the core pipe 3, the core pipe 3 can be pulled out as it is.

As described above, according to this invention, it is possible to reliably prevent the lead pipe from flying out when disassembling or assembling the mechanical pencil.
In particular, it is possible to obtain a mechanical pencil with excellent practical effects such as improved working efficiency, which allows the core pipe to be taken out as necessary during assembly and adjustment.

Incidentally, the present invention is not limited to this embodiment, and any writing instrument in which there is a risk of the core pipe coming out during disassembly or assembly, such as mechanical pencils and ballpoint pens in which the cushion spring 8 for cushioning excessive writing pressure is not inserted, may be used. Applicable to

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of the mechanical pencil according to this invention.
FIG. 2 is an enlarged cross-sectional view of the bulging portion of the core pipe, and FIGS. 3 and 4 are enlarged cross-sectional views of the locking portion. 1... Outer tube, 2... Cap, 3... Core pipe, 4...
...Locking part, 5... Lead chuck, 6... Chuck ring, 7... Sleeve, 8... Cushion spring, 9... Knock spring, 10... Swelling part, 11. ...Through hole, 12...groove.

Claims (1)

[Scope of utility model registration request] A core pipe 3 is housed in an outer cylinder 1 so as to be movable in the axial direction, and a node chuck 5 is connected to the tip of the core pipe 3.
a snub 7 that is movable relative to the outer cylinder 1 while in contact with a chuck ring 6 that tightens the sleeve; a knock spring 9 that is inserted between the sleeve 7 and the core pipe 3; A locking portion 4 protruding from the outer cylinder 1 holds and supports the rear end of the cushion spring 8 that is engaged with the cushion spring 8, a groove 12 provided in the locking portion 4, and a groove 12 provided in the locking portion 4. A mechanical pencil comprising a bulge 10 formed in a part of the core pipe 3 at the rear and engages with the locking part 4 via the groove 12.