US2184529A

US2184529A - Mechanical pencil

Info

Publication number: US2184529A
Application number: US297241A
Authority: US
Inventors: Lucifer J Most
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-09-30
Filing date: 1939-09-30
Publication date: 1939-12-26
Anticipated expiration: 1956-12-26

Description

Dec. 26, 1939. L. J. Mos-r MECHANICAL PENCIL FiledSept. 30, 1959 INVENTOR luif- Most. WM

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atented Elec, 2S, i939 STATES PATENT orrica 5 Claims.

My invention relates to mechanical pencils of the type in which the lead is an instrumentality of the pencil mechanism.

The object of the invention is to provide leads that will interlock in the means for feeding the lead and thereby provide a continuity of feed.

In my allowed application Serial No. 279,072, iiled June 14, 1939, allowed July 21, 1939, I have disclosed a pencil with prismatic leads which is the shape most suitable for leads whose average diameter in cross-sectional area is less than 115th of an inch. For leads having in cross-section diameters larger than gth of an inch the shape may be either cylindrical or oval, and therefore not necessarily prismatic, as the guides in such larger diameters can be easily made to suit the cross-section of the larger diameter of either oval or circular shaped leads in cross-section.

In the appended drawing forming part or' this application, Figure 1 is a fragmentary vertical section on line I-I, Figure 2, showing a pencil embodying my invention.

Figure 2 is an enlarged cross-section on line 2 2, Figure 1.

Figure 3 is an enlarged cross-section of a pencil having an oval shaped lead guide, and thereore, oval shaped lead in cross-section, and

Figure 4 is a perspective view of a lead oval in cross-section.

Referring to the drawing, 5 is a barrel which is provided with a customary tip 5 terminating at the lead outlet with a threaded bore 7. Positioned within the barrel and revolving relatively thereto is a magazine 8 having a lead guide 9 of circular cross-section extending through the bore lil of the tip and leading to the threaded bore l.

The magazine is provided with an outer bead Il bearing against a ring I2 secured within the barrel, and with the bearing of the end of the lead guide 9 on the bottom of the bore I0, the

magazine is prevented from longitudinal dis.

placement in the barrel. The magazine carries an eraser I3 and a cap Id by which the magazine may be turned in the barrel. The leads I5 for the pencil in this particular case are cylin drical and are circular in cross-section similar to the lead guide 9. To prevent the lead from turning in the guide the lead is provided with a keyway I6 which is engaged by protuberances I1 formed in the guide preferably near the ends thereof.

Each of the leads has its ends cut on a bias, that is to say, forming slopes Ie which are at an angle with the axis of the lead. When a lead is fed through the threaded bore 'l of the tip by the turning of the magazine, the upper end of slope I8 of a lead I5 passes from the magazine into the guide 9 when another lead I5 will enter into the guide 9 following the lead which is already in the guide. If the two slopes I8 of the contacting leads do not meet properly at the time, they will travel that Way toward the threaded bore l' until the lower lead I5 passes substantially into the threaded bore 'l when it will remain stationary, while the lead above it will be turned by the guide 9 which turns with the magazine. This brings the slope I8 thereof in register with the upper slope I8 of the lower lead I5 positioned in the threaded bore 'I of the tip, as shown in Figure 1. In consequence of this engagement, the lower portion of the lead I5 will turn when the upper lead I5 above it is turned by the magazine through the guide 9. This engagement of the contacting slopes of the leads insures the expulsion of the lead section engaged in the threaded 20 bore l.

In Figure 3, the lead barrel 5f has the lead magazine 8 provided with a lead guide 9' which is circular exteriorally but oval interiorally, that is, the passage I0' of the lead guide is oval in 25 cross-section to engage a lead I5' of similar crosssection. In this arrangement no keyways in the lead proper are necessary since the lead will not turn in the lead guide, although it is free to move longitudinally due to its shape.

Figure 4 illustrates in perspective a lead as shown in the cross-section of Figure 3.

In lieu of forming a. keyway, as shown in the leads of Figures 1 and 2, a flat surface in lieu thereof could be provided which will answer the same purpose. It is self-evident that the lead guide will have corresponding flat surfaces to engage the lead and prevent it. from turning while permitting it to move longitudinally thereof.

The fact that the lower lead when entirely in the threaded bore 1 remains stationary but the lead above it will turn until the two slopes meet, does not necessitate an exact cutting of the slope or relatively to the configuration of the lead used.

Although the description and drawing refer to a threaded tip mechanism, it is obvious that a threaded member for the lead may be located at any other portion in the barrel or tip using the lead described, that is, a lead having the ends cut on a bias.

I claim:

1. In a mechanical pencil, a. lead, means for feeding the lead, and means for preventing the lead from turning while permitting the lead to move longitudinally thereof, said leads having its ends cut on a. bias.

2. A lead for a mechanical pencil having its ends cut on a bias.

3. In a mechanical pencil, a combination of a lead having its ends cut on a bias, and a guide for lead which permits said lead to move longitudinally but prevents it from turning therein.

4. A lead for mechanical pencil having sloping ends.

5. A lead for mechanical pencil having sloping 5 ends lying in substantially parallel planes.

LUCIFER J. MOST.