Mechanical pencil

Details Mechanical pencil Mechanical pencil

1986-03-14

1987-12-22

Scanlan, Jr., Richard J.

Coating implements with material supply

Solid material for rubbing contact or support therefor

Including means to advance material

401 67, 401 94, B43K 2116

Patent

active

047143657

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

This invention relates to a knocking type mechanical pencil, and particularly to a mechanical pencil which can accomplish lead-feeding operation by way of knocking and in addition, can project a lead from a lead guide merely by pushing the lead against the surface of paper or the like, thus rendering writing possible to perform.


BACKGROUND

In case of performing writing by a mechanical pencil, the length of a lead projected from the end of a lead guide is limited to a substantially predetermined amount beyond which the lead is liable to be broken, and when the length of such projection is reduced due to the wear or the like during writing, it is necessary that for example, a button or the like provided at the rear end of a lead pipe is knocked to thereby deliver the lead of the desired length.
However, since this lead-feeding operation is not carried out unless the writing operation is discontinued, there gives rise to a problem in that the writing efficiency is deteriorated.


DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a solution of these problems noted above with respect to prior art. An object of the invention is to provide a mechanical pencil wherein a slider engaging a lead and an outer tube with different frictional resistances is provided for effecting lead-feed by a delivery mechanism other than a general knocking operation, whereby the end of a consumed lead is pressed against or released from a surface of paper or the like to thereby project the lead from a lead guide by an amount corresponding to backward movement of the slider. The lead-feeding may be easily performed merely by pressing operation without changing the grip of the outer tube.


BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of essential parts showing one embodiment of a mechanical pencil having a slider member in accordance with the present invention;
FIG. 2 is a sectional view of the whole structure of the pencil;
FIG. 3 is a sectional view of the whole structure of the pencil according to a further embodiment;
FIG. 4 is a perspective view of a slider member;
FIG. 5 is a side view of a slider member;
FIG. 6 is a front view of a slider member;
FIG. 7 is a sectional view taken on line A--A of FIG. 5;
FIG. 8 is a longitudinal sectional view of another embodiment;
FIG. 9 is a plan view, partly broken away, of the embodiment of FIG. 8;
FIG. 10(a) is a perspective view of a stopper portion;
FIG. 10(b) is a perspective view of another stopper portion;
FIG. 11 is a longitudinal sectional view of another embodiment; and
FIG. 12 is a plan view, partly broken away, of the embodiment of FIG. 11.


BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described with reference to the drawings.
In FIGS. 1 and 2, reference numeral 1 designates an outer tube which can be gripped by a hand, the outer tube 1 having a fore means 2 provided integrally therewith. It is to be noted that the fore means 2 can be one separated from the outer tube 1 as shown in FIG. 3.
A lead pipe 3 is coaxially inserted into the outer tube 1, and a lead chuck 4 is connected to the end of the lead pipe 3. A receiving member 5 is detachably fitted in the rear end of the lead pipe 3 to accommodate an India rubber 6 therein. The end of the lead chuck 4 extends through the center of a chuck fastening ring 7, and the rear end of the chuck fastening ring 7 is opposed to a flange 8a at the front portion of a cushion sleeve 8 which is axially movable within the outer tube 1. The cushion sleeve 8 is formed of a resilient member such as deformable polyacetal or other resiliently deformable resilient members, the cushion sleeve 8 being formed into a cylindrical configuration as a whole, and the cushion sleeve 8 is provided at the rear end with a stopper portion 8c which projects outwardly from the outside diameter of a body 8b. The body 8b is provided with a cut 8d and provided at the rear end with an axially extending cut 8e so that the stopper portion 8c may generate a suitabl

REFERENCES:
patent: 3864046 (1975-02-01), Butka
patent: 4358210 (1982-11-01), Hashimoto et al.
patent: 4360280 (1982-11-01), Sekiguchi et al.
patent: 4362410 (1982-12-01), Hashimoto
patent: 4371277 (1983-02-01), Kageyama et al.
patent: 4382706 (1983-05-01), Hashimoto et al.

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