US2460323A

US2460323A - Mechanical pencil

Info

Publication number: US2460323A
Application number: US681644A
Authority: US
Inventors: Charles E Wehn
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-07-06
Filing date: 1946-07-06
Publication date: 1949-02-01
Anticipated expiration: 1966-02-01

Description

C E WEHN MECHANICAL PENCIL Flled July 6 1946 Feb 1, 1949 Patented Feb. I, 1949 UNITED STATS FFICE 6 Claims. (Cl. 12018) This invention relates to mechanical pencils, and especially to improvements in the propelling mechanism whereby the lead is advanced.

The object of the present invention is generally to improve and simplify the construction and.

operations of pencils of the mechanical type; to provide a mechanical pencil in which the number of parts employed is reduced to a minimum; to provide amechanical pencil which consists of a barrel section, a point or lead-carrying section, and a propelling mechanism for advancing the lead as it wears away; to provide a propelling mechanism which may be assembled as a complete unit before it is inserted in the barrel; to provide a novel form of anchor mechanism whereby the propelling mechanism is permanently secured after insertion in the barrel; and further, to provide means for imposin a constant frictional resistance on the propelling mechanism to take up Wear and to prevent accidental rotation of the propelling mechanism.

The mechanical pencil is shown by way of illustration in the accompanying drawings in which:

Fig. 1 is a central vertical longitudinal section of the pencil;

Fig. 2 is a side elevation of the propelling unit as it appears before being inserted in the barrel; and

Fig. 3 is a cross-section taken on line III-III of Fig. 1. p

Referring to the drawings in detail, and particularly Figs. 1 and 2, A indicates the point or lead-receiving end of the pencil, B the barrel, and C the propelling or lead-advancin mechanism. The point end is of the usual construction, that is it has a lead-receiving passage 2 formed therein for the reception of a lead 3 which may be inserted from the point or front end or from the rear end of the passage. The point is provided with a threaded extension 4 which screws into the front end of the barrel to permit removal of the point when inserting the lead from the rear. 7

The barrel is cylindrical-shaped in cross section and may be as long as desired. It is threaded internally at the front end to receive the threaded extension of the point A and is otherwise provided with a propeller rod guide and a plurality of keyways 6, the function of which will hereinafter he described.

The propelling mechanism consists of a nut having a rearwardly extending tubular portion 8 with a reduced end 9, a shoulder ill being formed between the main tubular portion and the reduced end 9. Extending through-the nut and the tubular extension is a threaded rod H and formed integral therewith is a pusher rod I2 which extends through the guide 5 and into the lead-receiving passage 2 to engage the lead 3. The rod is flattened as at M and the flattened portion is extended to one side to form a key l5 which extends into one or another of the keyways 8 formed in the inner surface of the barrel. This key secures the rods 5 i' and it against rotation with relation to the barrel and pencil point, but.

permits free longitudinal movement of the rods.

Secured in the rear end of the barrel is a collar it through which the reduced end 9 of the tubular member 8 extends. The shoulder I0 abuts the inner face of the collar and a cap I! abuts the outer face of the collar. The collar will hereinafter be referred to as an anchor member as it is pressed in and permanently secured when inserted in the end of the barrel. The cap I1 is similarly pressed on and is permanently secured on the reduced end 9 of the tubular member, hence the reduced end of the tubular member also functions as an anchor member. The cap l7 serves the function of a rotor. That is, by holding the barrel and rotating the cap, tube 8 and nut 1 are rotated and as the threaded rod I l is held against rotation by the key E5, the pusher rod I2 will be either advanced or retracted depending upon whether the cap is rotated in one direction or the other.

In actual practice it is possible when applying and securing the cap ll that a frictional contact is made between the inner end of the cap and the collar, and similarly between the shoulder Ill and the collar, but such frictional contact would soon wear away and the cap and the nut actuated thereby might rotate so freely as to cause accidental advance or retraction of the pusher rod and lead. To avoid this and at the same time make it possible to take up wear, an annular recess I8 is formed in the collar 56 and a small helical compression spring i9 is inserted therein.

This spring pushes against the inner end of the cap and thus holds the shoulder H} in frictional contact with the collar it, the friction being just sufficient to resist rotation of the cap accidentally. Also, as wear takes place, the spring extends and the friction imposed remains substantially constant.

The pencil as a whole consists of a minimum number of parts which are simple tomanufacture and assemble. The parts forming the propeller unit may be assembled durin manufacture as shown in Fig. 2, and then by inserting this unit into the barrel and pressing the collar 56 into place, assembly is completed and all parts are permanently held against removal from the barrel by the two anchor members, to wit the collar l6 against which the shoulder l6 abuts and the reduced end 9 on which the cap is pressed and secured.

The only metallic parts required are the thread-- such as the cap, the barrel and the point may be made of a suitable plastic or similar material, and while this and other features of the invention have been more or less specifically described and illustrated, it should be understood that changes may be resorted to within the scope of the appended claims and that the materials and finish of the several parts employed may be such as the experience or judgment of the manufacturer may dietate or varying conditions or uses may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a pencil having a barrel section and a point section at its forward end with a lead-receiving passage formed therein, an anchor member secured in the rear end of the barrel, a nut within the barrel, a tubular extension on the nut extending through the anchor member and being rotatable therein, a threaded rod extending through the nut and into the tubular extension, cooperating means on said threaded rod and the barrel securing the threaded rod against rotation with relation to the barrel, a pusher rod forming an extension of the threaded rod and extending into the lead-receiving passage, and means fixed on the outer end of the tubular extension to rotate the tubular extension and the nut to advance or retract the threaded rod and the pusher rod.

2. In a pencil having a barrel section and a point section at its forward end with a lead-receiving passage formed therein, an anchor member secured in the rear end of the barrel, a nut within the barrel, a tubular extension on the nut extending through the anchor member and being rotatable therein, a threaded rod extending through the nut and into the tubular member, cooperating means on said threaded rod and the barrel securing the threaded rod against rotation with relation to the barrel, a pusher rod forming an extension on the threaded rod and extending into the lead-receiving passage, and a cap fixed on the outer end of the tubular extension to rotate the tubular extension and the nut to advance or retract the threaded rod and the pusher rod connected therewith.

3. In a pencil having a barrel section and a point section at its forward end with a lead-receiving passage formed therein, a collar anchored in the rear end of the barrel, a nut within the barrel, a tubular extension on the nut, a reduced end on said tubular extension, a shoulder formed between the reduced end and th tubular member, said reduced end extending through the collar and being freely rotatable therein, said shoulder engaging the inner end of the collar, a threaded rod extending through the nut and into the tubular extension, cooperating means on said threaded rod and the barrel securing the threaded rod against rotation with relation to the barrel, a pusher rod forming an extension of the threaded rod and extending into the lead-receiving passage, and means fixed on the reduced end of the tubular extension to rotate the tubular extension and nut to advance or retract the threaded rod and the pusher rod connected therewith.

4. In a pencil having a barrel section and a point section at its forward end with a leadreceiving passage formed therein, a collar anchored in the rear end of the barrel, a nut within the barrel, a tubular extension on the nut, a reduced end on said tubular extension, a shoulder formed between the reduced end and the tubular member, said reduced end extending through the collar and being freely rotatable therein, said shoulder engaging the inner end of the collar, a threaded rod extending through the nut and into the tubular extension, cooperating means on said threaded rod and the barrel securing the threaded rod against rotation with relation to the barrel, a pusher rod forming an extension of the threaded rod and extending into the lead-receiving passage, a cap fixed on the reduced end of the tubular extension to rotat the tubular extension and nut to advance or retract the threaded rod and the pusher rod connected therewith, and a spring between said collar and said cap for urging said shoulder against said collar.

5. In a pencil having a barrel section and. a point section at itsfo ward end with a lead-.receiving passage formed therein, an anchor member secured in the rear end of the barrel, a. nut within the barrel, a tubular extension on the nut extending through the anchor member and being rotatable therein, a threaded rod extending through the nut and into the tubular extension, cooperating means onsaid threaded rod andthe barrel securing the threaded rod against rotation with relation to the barrel, a pusher rod forming an extension on the threaded rod and extending into the lead-receiving passage, a cap fixed on the outer end of the tubular extension to rotate the tubular extension and the nut to advance or retract the threaded rod and the pusher rod connected therewith, and means 19. imposing friction to resist rotation of the cap and connected members with respect to said anchor member.

6. In a pencil having a barrel section and a point section at its forward end with a lead-receiving passage formed therein, a collar anchored in the rear end of the barrel, said collar having an annular recess therein, a nut within the bar.- rel, a tubular extension on the nut, a reduced end on said tubular extension, a shoulder formed between the reduced end and the tubular member, said reduced end extending through the. collar and being freel rotatable therein, said shoulder engaging the inner end of the collar, a threaded rod extending through the nut and into the tubular extension, cooperating means on said threaded rod and the barrel securing the threaded rod against rotation with relation to the barrel, a pusher rod forming an extension of the threaded rod and extending into the lead-receiving passage, and a cap fixed on the reduced end of the, tubular extension to rotate the tubular extension and nut to advance or retract the threaded rod and the pusher rod connected therewith, and a spring in said annular recess interposed between the cap and the collar, said spring impose ing friction to resist rotation of the cap and connected members with respect to said collar.

CHARLES E. WEHN.

REFERENCES CITED The following-references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,319,039 Bergen Oct. 21, 1919 1,540,920 Berryman June 9, 192:5 2,287,3651 Wehn June 23, 1942