US1490245A - Mechanical pencil - Google Patents

Description

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Patented Apr. E5, 1924.

UNETED STATES PATENT OFFICE.

JOHN C. WAHL, OF CHICAGO, ILLINOIS, ASSIG-NOR TO THE WAHL COMPANY, OF

WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

MECHANICAL PENCIL.

Application filed March 29, 1920. Serial No. 369,688.

To all whom it may concern:

Be it known that I, JOHN C. VVAHL. a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Mechanical Pencils, of which the following is a specification.

My invention is an improvement in mechanical pencils and has for its object the provision of an improved feeding action for pencils of this type.

My 'nvention is especially designed to be used in connection with the mechanical pencils disclosed in the patent to Keeran, No. 1,151,016, granted August 24, 1915, and is especially designed to provide .a means of retracting the lead of the pencil in case this lead has been protruded through the tip farther than necessary.

My invention may be best understood by reference to the accompanying drawings, of

which:

Fig. 1 is a sectional view of a pencil equipped with my invention;

F Fig. 2 is a section along the line 2-2 of Fig. 3 is an enlarged viewof the plunger and lead;

Fig. 4 is a detail of the end of the plun- ;Fig. 5 is a section along the line 5-5 of ig. 4; q Fig. 6 is a section along the line 66 of Fig. 1, and

Fig. 7 is a section along the line 7-7 of Fig. 1.

My improved pencil consists of a casing 10 which is provided-with a conical end 11, so dered in which is a tube 12, in which is a thread 13 adapted to receive the tip 14. This tip may be either provided with longitudinal ridges, as shown in the cited patent to Keeran, or may be left smooth. A lead 15 is guided by a rear end of the tube 12 into the tip 14. The tube 12 is made of approximately rectan lar section, as is shown by the section in ig. 7 and serves to prevent the rotation of the plunger 16. which serves to force the lead through the tip. The plun er 16 is rotatably mounted lnto the cross ead 17, which is provided with screw threads 18, preferably of rectangular sec- .tion, which en age in a threaded sleeve 19 secured to the mterior of the pencil casing 10. before noted, the crosshead 18 is which are soldered into a head 24, on which is frictionally mounted the cap or tassee 25. The structure of the magazines and tassee is similar to the structure of these parts shown in the cited patent to Keeran. The plunger 16 at its forward end is provided with a hole 26 and a plurality of slots 27, thus forming a set of prongs 28. Normally these prongs are sprung inwardly, so, as to make the hole 26 slightly smaller. than the end of the lead 15, so that when the lead is inserted in the hole 26 it will be held in said hole by frictional engagement with the prongs 28.

Mounted on the upper end of the tube 12 is a funnel 29, which is rigid with the tube 12 and is supported in the inside of the casing. A second funnel 30 is soldered to the lower ends of the magazines 22 and 23, thus serving to hold them together.

The operation of my improved pencil is as follows:

When it is decided to feed the lead 13 1 through the tip 14, the tassee 25 is rotated,

thereby rotating the crosshead 17 and advancing the plunger 16, which is held from rotation on account of the rectangular section of the tube 12. The lead is thus fed for- It is to be noted that the plunger '30 is provided with a round hole a proximately the diameter of the outside 0 the plunger 16, as shown in Fig. 6, since in order to ad-' vance the. plun er it is necessary that the magazines to w 'ch the funnel 30 is rigidly ggtached be rotated relative to the plunger entire length, it is obvious that this will not be necessary, since it is only necessary to provide a rectangularseetion at the bottom of the funnel 29.

Many departures from and variations may made in the specific structure herein shown without departing from the spiritof my invention, since I claim:

In a mechanical pencil comprising a bar- 20 rel having an internally threaded section therein and being tapered at one end; a tip mounted on the tapered end, and a lead guide tube rectangular in cross section and mounted in the forward end of said barrel," 26

a lead feeding mechanism comprising a crosshead loosely mounted on the rear end of the ilun 'er rectan ular in cross section and enl3 '5 gagingsaid internally threaded section in the barrel, a rotatable means reserve lead magaz1nc ,'for rotating the crosshead within the barreland causing the said plunger to enter the lead guide tube and move forward in a nonrotatable movement thereby ejecting a lead through the tip.

In Witness-whereof I have hereunto subscribed my name.

JOHN C. WA.

including a 30