US2333876A - Mechanical pencil - Google Patents

Description

Patented Nov. 9, 1943 MECHANICAL PENCIL Fred P. Moore, Chicago, Ill., assignor to Eversharp, Inc., Chicago, 11]., a corporation or Dela- Application January 19, 1942, Serial No. 427,219

4 Claims.

This invention relates to mechanical pencils and finds particular utility in mechanical pencils oi the type wherein the lead is fed step by step to the writing point from a magazine by depressing a button or feed actuating member which projects from the upper or rearward end oi the pencil barrel.

One of the objects of the invention is the provision of a construction which will permit the barrel to be made entirely 01' one of the suitable so-called plastic materials, such as pyroxylin, and with thin walls, without requiring a metallic liner to reinforce or stiflen it, and at the same time provide eil'ective stiffening support for such a barrel and a secure mounting for a clasp or clip provided for retaining the pencil in the pocket of a garment or the like.

Another object is the provision of a construction which obviates the likelihood of inadvertent operation of the lead feeding mechanism in instances where pressure is applied to the operating button when pushing the pencil down to engage the clasp or clip with the hem of the pocket.

Other objects include the provision or a construction in which the entire mechanism, including the clip, may be mounted in and removed from the barrel as a unit and wherein they are all securely retained in proper operative relationship when so mounted.

Yet another object is the provision of a construction wherein the retention oi the clip is very secure and the barrel is relieved of the stresses imposed on the clip mounting in the operation of springing the clip into retentive engagement with the hem oi the pocket.

Other and further objects and advantages of the invention will be pointed out or indicated hereinafter, or will be apparent upon an under.- standing oi? it or use of it in actual practice.

For the purpose of aiding in explanation of the invention, I show in the accompanying drawing, and hereinafter describe, one form in which it may be embodied. It is to be understood, however, that this particular construction is presented merely by way example and that the invention may be embodied in other forms without departing from the scope of the appended claims.

In said drawing,

Fig. 1 is a side view of a pencil embodying the invention, the barrel being shown in longitudinal section and various other parts being broken away to show features or the construction;

' Fig. 2 is a perspective view oi the upper end of the barrel illustrated in Fig. 1 but on a larger scale; I

Fig. 3 is a side elevational view of the upper end portion of the assembly shown in Fig. 1, but on a larger scale and as viewed from. the lefthand side 01' Fig. 1, the eraser holder being shown in a position inverted from that shown in Fig. 1; and

Fig. 4 is a partial cross section on line 4-4 of Fig. 3.

The nature of the invention will be most quickly ascertained from the following description of the illustrative embodiment shown in the drawing.

The barrel i0 is adapted to be made oi. a suitable plastic material, pyroxylin, for example, and is of tubular form, aflording a bore 01' suitable diameter for accommodation of the lead handling mechanism. It may be slightly tapered at its lower end portion, and in its upper end portion is provided with a narrow slot Illa leading into the bore and extending from the open upper end of the barrel. Not all details of the lead handling mechanism are shown in the drawing but it is to be understood that it represents mechanism of the step-by-step lead feeding type, for example, such as is more fully disclosed in the U. S. patent to Stenersen No. 2,158,991. In so far as here illustrated, the mechanism includes a magazine tube Ii adapted to contain a plurality'oi lead sticks and a guide tube I 2 into which the lead sticks are fed one aiter another from the magazine and in which they are guided to a clutch l4 wherein the lowermost lead stick is gripped and by which it is moved forwardly in the lead feeding operation to project it at the writing point 0! the tip IS. The guide tube i2 is reciprocably mounted in a sleeve II which has a shouldered portion seating on an internal shoulder lflb'of the barrel, in which position the lower end portion of the sleeve projects beyond the lower end of the barrel and is screw threaded at lib for the screwing on of the tip l5. When screwed into place, the upper end of the tip abuts the lower end 01 the barrel and securely clamps the shouldered portion of the sleeve ii against the seating shoulder lflb, thus fastening said sleeve in the barrel. Although reciprocable in the sleeve IS, the guide tube I2 is secured against withdrawal upwardly therefrom and as the guide tube is fastened immovably to the magazine tube H, the entire mechanism is secured as a unit within the barrel. A helical spring I! is compressed between the upper end or the sleeve I! and the lower end of the magazine, 50 that it normally retains those parts in the relationship shown. In the upper end of the magazine tube is reversibly mounted an eraser holder I! in which is retained an eraser l9, and the upper portion of the magazine tube is formed with inwardly projecting shoulders 20 and 2| of which the first mentioned affords a rest or stopping abutment for the eraser holder when the latter is in the position shown in Fig. 1, the shoulder 2i likewise forming a rest or stopping abutment for the eraser holder when it is in the inverted position, viz., with the eraser housed within the magazine tube. In either of said positions of the eraser holder, it or the eraser projects beyond the upper end of the barrel to function as a push button or actuating member. By manually push ing the projecting portion into the barrel, the

magazine tube II and guide tube i2 are moved downwardly against the pressure of spring I! and by such operation the lowermost lead stick is fed forwardly by the clutch l4. Upon release of the pressure from the actuating member, the shifted parts are returned to their normal position.

The bore of the barrel and the diameter of the magazine tube II are such that the latter lies close to the bore wall, but without fitting so tightly as to interfere with their relative reciprocatory movement, and by virtue of their relationship,

the magazine tube functions as a stifiener for l the barrel, limiting its deflection, particularly along its mid portion. Consequently, the barrel may be made with comparatively thin walls.

A clasp or clip 22, which may be of conven- V tional form, is provided for the customary purpose of clasping the pencil to a portion of a garment pocket or the like, in order to hold it upright and prevent its falling out. Instead of being attached to the barrel, as' has been generally the case, or to a separately removable cap, this clasp is attached to the upper portion of the magazine tube. The clasp is formed with a slender shank portion which at its lower end terminates in a bulb or detent portion 220, and at its upper end it is formed with a mounting portion comprising flanges 22b extending from opposite side margins of the shank and each car.- rying a pair of tangs Me. The magazine tube is slotted to permit insertion of these tangs through it, and they are then bent inwardly against the inner surface of the tube to fasten the clasp to it. In the locations where the tangs overlap the inner surface 'of the tube, the latter is embossed outwardly, as at Ila, to afford depressions in which the bent-over tangs seat so that their inwardly presented surfaces are flush with the inner surface of the magazine tube. As thus mounted on the magazine tube, the clasp is a part of the mechanical unit assembly.

This assembly, comprising magazine tube. ll, clasp .22, guide tube l2, spring i1, sleeve I8 and clutch, is inserted in the barrel through the upper end thereof, the clasp mounting being positioned in slot Hia of the barrel, and when the tip I5 is screwed onto the lower end of sleeve IS, the entire mechanical unit including the clasp is held in operative assembly with the barrel.

, When thus assembled, the shank of the clasp ex.-

tends longitudinally along the barrel and the detent member 22a rests in contact with the outer wall of the barrel.

The slot Illa is somewhat longer than the clasp -mounting 22b, so the latter may slide downwardly in the slot when the push button is deprased to perform the lead feeding operation. When the parts are in normal position, the lower portion of the slot is covered and concealed by the clasp shank.

It will be seen that by virtue of this construction the clasp has a very secure mounting on the magazine tube, which may be made of metal having the requisite tensile strength and stiffness, permitting the tangs Me to be very tightly clenched and affording a suitably strong anchorage even though the parts may be small. Consequently, the stresses which are imparted to the clasp securing means when the shank is sprung away from the barrel by intrusion of a thick layer of fabric between them, are surported by the metallic tube II, the relatively tender thinwalled barrel thereby being relieved of all such stresses. This likewise provides a much more stable mounting for the clasp than would be the case if it were mounted on the barrel, and the effectiveness of the gripping action of theclasp is thereby rendered more certain and permanent.

I claim:

1. In a mechanical lead pencil, a tubular barrel, lead feeding means mounted therein and having a part which is reciprocable longitudinally in the barrel and an actuating part projecting beyond the upper end of the barrel for operating manually to effect the lead-feeding operation, and

a clasp secured to said longitudinally reciprocable part independently of said actuating part and reciprocable therewith relative to the barrel, said clasp including a part disposed exteriorly of the barrel and extending alongside the same in position to press an interposed article against the side of the barrel.

2. A mechanicalpencil having a tubular barrel provided with a slot extending longitudinally from its rearward end, a lead propelling member reciprocable longitudinally within the barrel and having a manually operable actuating part extending beyond the rearward end thereof, and a clasp affixed to said longitudinally reciprocable lead propelling member and reciprocable therewith relative to the barrel, said clasp extending through said slot and having a portion disposed exteriorly of and alongside the barrel for cooper ation therewith to grip an interposed article.

3. In a mechanical pencil. the combination with a tubular barrel and a lead-feeding member reciprocable longitudinally therein, of a clasp affixed to the lead-feeding member within the barrel and reciprocabletherewith relative to thebarrel,'and a manually operable actuating part engaged with the lead-feeding member and projecting through the rear end of the barrel, said clasp having a portion disposed exteriorly of the barrel and alongside the same in position for cooperation with the barrel to grip an interposed article.

4. In a mechanical pencil, a structure as specifled in claim 3 and wherein the barrel is provided with a longitudinal slot through which the clasp extends and which accommodates longitudinal movement of the clasp relative to the barrel and the lead-feeding member and clasp are removable as a unit from the barrel.

FRED P. MOORE.

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