US2100007A - Mechanical pencil - Google Patents

Description

Nov. 23, 1937. P. s. HAUTON MECHANICAL PENCIL Filed Feb. 24, 1933 N m R Y U ,ME mm FN Q R E 1 o W 4. n lim 5 I RNA m 1 P .3 0 @MN h\ 8% I; @b\ Q Q\ 8\\ Patented Nov. 23, 1937 2,10otn1 UNITED STATES PATENT OFFICE MECHANICAL PENCIL Paul S. Hauton, Atlanta, Ga.

Application February 24, 1933, Serial No. 658,355

2 Claims.

This invention relates to mechanical pencils and has more special reference to pencils in which the lead holding member travels the entire length of the pencil so that a lead substantially as long as the pencil may be used.

comprehensively stated, the invention aims to provide a simplified mechanical pencil which is so balanced and constructed as to afford writing ease and correct finger position. In order to achieve writing ease, the portion of the pencil remote from the writing end should be as light as possible and to accomplish this in a pencil in which the lead holder travels substantially the entire length of the pencil is one of the objects of the invention. While my copending application Serial No. 644,612, discloses an auxiliary sleeve of resilient material adapted to be slipped over the end of the pencil for promoting ease and correctness of finger grip, the present invention aims to utilize the auxiliary sleeve as a manually operable shell or casing part for driving one of the lead moving members and forming a pencil having a smooth exterior except for an annular protuberant portion in the region of the exposed lead guide tip. In order to maintain the flexible resilient sleeve in shape to withstand the finger pressure exerted thereon during the writing operation, a stiffening sleeve is utilized which, however, not only stiffens the resilient member but also affords a drive connection to one of the lead moving members'and locks an exposed writing tip in place. In this manner, a mechanical pencil is achieved which affords writing comfort, which has a simplified construction at the Writing end and which requires such a small space for the driving and aligning locking arrangement that the appearance of the pencil is not impaired.

While one embodiment of the invention is shown in the drawing accompanying this application and forming part thereof, it is to be understood that such embodiment is merely illustrative of the underlying principles of the invention so as to aiford a clear understanding thereof to those skilled in the art and is not intended as limiting the invention to the specific form disclosed therein.

In said drawing:

Fig. 1 is a vertical section through a mechanical pencil made according to the present invention.

Fig, 2 is an outside view of the same, and Fig. 3 is a section of Fig. 1 on the line 3-3. Referring now more in detail to the illustrathe free end'of the helically wound strip in place. This helix encloses a rotatable slotted feed tube ll, presenting a slot Ila on one side which is closed off near the writing end of the pencil to stop the travel of one of the longitudinally moving wings of the pencil holder, as will be described hereafter. This feed tube ll just clears and forms a sliding fit with the inner edge of the helical thread of the surrounding barrel, but as the latter is rigidly supported by the outer shell of the pencil stem while the feed tube is fixedly connected with the writing tip, both are movable in relation to each other in the same way as the writing tip is movable in relation to the outer shell of the stem, 1. e., they can be rotated around their common axis in relation to each other, as will be hereafter more fully explained. Theouter shell or barrel of the pencil is formed by a conically tapered tube l2, preferably of some light weight material such as paper, thin sheet metal or the like, the taper running toward the top of the pencil, as Figs. 1 and 2 indicate. The extremities I21; and l2b, however, are spun or pressed out into straight cylindrical ends to form seats for cylindrically formed members l3 and I4. Member I3 is a bushing or spacer, driven flush with the edge l2c of the inner end. 12a of the shell and having its interior end l3a contracted so as to form a tight fitting collar around the helix l0, fixedly supporting the latter and keeping it in axial alignment with the shell 12. Intothe straight end portion Hi), the cap I4 is inserted. This cap is preferably a spun metal thimble with a bead Ma formed around it to serve as a stop or shoulder abutting the end of the shell l2. The annular hollow space l5 between the outer shell and the helix l0 may, if desired, be utilized as a magazine for loose pencil or crayon bars and the inserted inner sleeve of the thimble below the bead may, with a slight modification of the parts concerned (not shown) providing a second support to the former. At any rate, said helix and the shell constitute a rigid fixed combination. In axial alignment therewith, but manually rotatable in relation thereto is provided the writing end, indicated in its entirety by l6. This end comprises essentially two parts; the point or lead guide tip Ilia and the finger grip sleeve Mb. The former part is essentially a conical frustum, preferably made of metal, axially perforated in suitable manner to enclose the members presently to be described. The taper of the front end of this guide tip is advantageously eased ofl toward a cylindrical extremity, as shown in Fig. 1, to provide a handy and slender writing tip from which the lead protrudes. the broad base l6c of the conical frustum abuts the holder in such a way that the abutting exterior surfaces of the holder and the guide tip form a fiush even conical mantle. The holder is a resilent member with which the fingers of the writer contact. The front end of the holder, which as aforesaid, first forms a conical continuation of the guide tip, is restricted at a short distance further up by a polygonal surface 16' intersecting with the lower circular cone l6a, its taper running in the opposite direction and forming an obtuse angle with the first named taper. The top part of the holder is cylindrical and runs flush into the cylindrical portion i2a of the shell l2, above described. The outer form of the holder, as illustrated, forms an annular stop or protuberant portion to prevent the fingers from slipping toward the point and to prevent the pencil from rolling as described in my copending application Serial No. 644,612. It was pointed out before that the writing tip l6, which carries the slotted feed tube II is in rotatable connection with the shell I! which, as shown, rigidly holds the internally threaded helix It) in position, thereby bringing these two parts I0 and II into similar respective motive relation, and these connecting means will now be considered in detail. Where the cylindrical part of the holder l6b abuts the shell portion lZa and the bushing l3, there is interposed an anti-friction washer ll of suitable material, whose outer rim is flush with both surfaces of shell l2 and holder I617. The bore of the non-metallic holder I 6b has an inner stiffening lining I! which protrudes at both ends. The upper protruding sleeve l8a forms a loose fit around the helix I 0 and projects into the clearance space between the bush ing l3 and the tubing of the helix. The lower protruding .end of the sleeve 3b is contracted into a smaller tube nozzle and is tightly fitted or driven into the lead guide tip Ma. The slotted feed tube ll, formerly described, is swaged over at its bottom end llb, and this swaged over rim is firmly clamped between the lower edge of the sleeve I81) and a shoulder or oifset in the bore which perforates the point or guide tip I Go. In

this way, a firm yet dismountable connection is effected between the writing tip it and the feed tube. telescoped into the threaded helix ID, as formerly described. The remaining members of the pencil controlling mechanism are the winged lead holder H which is adapted to ascend or descend inside theinner spiral thread of the helix III by means of a wing l9a, projecting through the slot in the feed tube H and engaging with the thread Ma; furthermore, the ejection or follower pin 20, slidably mounted within said feed tube and provided with a wing or lug 20a, projecting likewise through the tube slot and engaging with the thread. The threaded tube or helix l0 terminates, as in the formerly described invention, short of the closed, portion of the slotted tube H and alsobefore the lining I8 is contracted, so as to provide a clearance where the wing of the lead holder I! may disengage from the thread and be arrested in its longitudinal downward movement while the ejector pin propels the stub end of the lead out of the lead holder. It will be observed that members l2 and I 6 form relatively rotatable juxtaposed manually operable members, the member l2 driving the helix and the member l6 driving the lining member or sleeve l 8, which also aflords an interlocking connection to the slotted tube II and holds the tip |6a in place.

I claim:

1. A mechanical pencil combining an exposed tip, lead moving means comprising a threaded helix, a member having a longitudinal slot concentrically arranged therewith and rotatable relatively thereto, a lead engaging member having a wing engaging the helix with means comprising relatively rotatable members for enclosing the lead moving means, a tubular member snugly fitted within one of the relatively rotatable members and locking with the tip, and a bushing between one of said members and the helix to lock the two together, the bushing having a tubular portion spaced from the helix to provide clearance for receiving the end of the tubular member.

2. A mechanical pencil comprising a tip having a lead guide orifice, lead moving means comprising a threaded helix, and a slotted member, means comprising relatively movable exterior members arranged end to end for housing and driving the lead moving means, a cylindrical liner fitting the inside of one of the exterior members and extending beyond the end of said member and into the other exterior member and having a reduced lower cylindrical end for seating and locking with the slotted member beyond the end of said one exterior member, and a tapered tip having a friction fit on the said reduced end of the liner and abutted against the opposed end of the said one exterior member.

PAUL S. HAUTON.

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