US2516938A - Mechanical pencil with screw feed - Google Patents

Description

Aug. 1., 1950 F. M. AIMES MECHANICAL PENCIL WITH SCREW FEED med-Feb. 10, 1950 l H 1 I. H I 1 l I I Q 1 i ,i i a :1

INVENTOR ATTORNEY Patented Aug. 1, 1950 UNITED STATES PATENT OFFICE f MECHANICAL PENCIL WITH SCREW FEED Francis M. Aimee, Maiden Bridge, N. Y.

Application February 10, 1950, Serial No. 143,431

This invention relates to what are generally referred to as mechanical pencils. More particularly, the invention deals with devices of this type and kind having a simple and economical screw mechanism for the positive feeding of a lead in forward and reverse directions, whereby the device can be produced and sold at a very nominal cost and, at the same time, a strong, durable and long-lasting device is provided.

The novel features of the invention will be best understood from the following descriptions, when taken together with the accompanying drawing, in which certain embodiments of the invention are disclosed and, in which, the separate parts are designated by suitable reference characters in each of the views and, in which:

Fig. 1 is a side and sectional View of a pencil made according to my invention diagrammatically illustrating a lead in extended position for use.

Fig. 2 is an enlarged section on the line 2--2 of Fig. 1. i

Fig. 3 is a view similar to Fig. 1 showing another form of construction; and

Fig. 4 is an enlarged section on the line 4-4 of Fig. 3.

In Fig. 1 of the drawing, I have shown a pencil 6 Claims. (Cl. 120-18) comprising a contracted and more or less bulletshaped tip end Ill, an elongated tubular barrel I l and a feed plunger [2. The barrel H has an inwardly spun or fashioned flange end I3 engaging the groove I4 in the tip ill.

The feed plunger 12 has a spiral feed groove l5 engaged by two or more inwardly-pressed keybeads It On the barrel ii to control feed of the plunger 12 by rotation of the barrel with respect to the tip.

Extending from what might be termed the lower end of the barrel, centrally thereof, is a rectangular rod ll which fits in a corresponding rectangular portion [8 of the bore 19 of the tip ll]. At the end of the rod 18 is a spring clip portion 20 for engaging a lead 2| to provide frictional or positive feeding of the lead in the tip ill; the bore 19 of the tip H) has a reduced guide bore 22 at its contracted end for support and slight frictional engagement with the lead 2|, this end of the section being split in accordance with the sectional view of Fig. 4, the latter being specifically applied to Fig. 3, but the tip portion of both forms of pencils shown is, in this respect, the same.

Considering now Fig. 3 of the drawing, here is shown a tip NJ, generally similar to the tip l0, and at l l is shown a barrel, the barrel being coupled with the tip Ill through an intermediate sleeve 23 having a key-engagement with the tip H) as at 24 for free rotation thereon.

The inner end of the sleeve 23, beyond the limits of the tip ID, has an enlarged internally threaded nut portion 25, upon which the barrel l I has a pressed or other firm mounting, so that the sleeve 23 and barrel II will operate as one unit. The bore IQ of the tip Ill is also of rectangular cross-sectional form to key itself with a rectangular rod 26 which differs from the rod l l primarily in being of larger diameter and having corner portions of the rods fashioned to form thread sections 2'! for operative engagement with the threads of the nut 25, so as to feed the bar 26 longitudinally of the tip In in expelling and repelling the lead which is mounted on the clip 28, similar to the clip 20'. The lead is not shown in Fi .3. i

The tip III has a small bore end 22', similar to the bore 22 and, as seen at 29 in Fig. 4. of the drawing, the contracted end of the tip is split so as to provide slight spring properties to this end for supporting engagement with the lead and to compensate for slight variances in diameters of the lead. 1

In both forms of the construction shown, the lead is positively extended or retracted by rota.- tion of the tip and barrel or the sleeve 23 as in Fig. 1, one with respect to the other.

From a standpoint of description, the complete mechanical pencil can be said to comprise a tip end and a barrel end with a plunger moved positively in both directions axially of the tip and, barrel in the feed of a lead supported thereon. In this connection, the rod 26 of Fig. 3 is the plunger, as is also the rod end ll of the plunger l 2. In Fig. 1, the enlarged portion of the plunger has a screw thread or screw feed engagement directly with the barrel, whereas in Fig. 3, this engagement is with the nut portion of the sleeve which is fixed to the barrel.

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

l. A mechanical pencil of the character described, comprising a barrel part and a tip end rotatably coupled with the barrel, 2. plunger mounted in and movable longitudinally of said barrel and tip, said tip having a rectangular bore, the plunger having a rectangular portion engaging the rectangular bore in the tip to key the tip and rectangular portion of the plunger against relative rotation, means for frictionally supporting a lead on the rectangular portion of said plunger, the tip having a contracted reduced bore-end through which a lead is adapted to pass, and cooperating means on the barrel and plunger providing longitudinal movement of the plunger axially of said tip upon relative rotation of the barrel and the tip.

2. A mechanical pencil of the character described, comprising a barrel part and a tip end. rotatably coupled with, the barrel, a plunger mounted inand movable longitudinally of said barrel and tip, said tip having a rectangular bore, the plunger having a rectangular portion engaging the rectangular bore in the tip to key the tip and rectangular portion of the plunger against relative rotation, means for frictionally supporting a lead on the rectangular portion of said plunger, the tip having a contracted reduced bore-end through which a lead is adapted to pass, cooperating means plunger providing longitudinal movement of the plunger axially of said. tip upon relative rotation of the barrel and tip, and said last, named means comprising a spiral groove on the plunger and an indentation on the barrel operatively engaging said groove.

3., A mechanical pencil of the character described, comprising a barrel part and a tip end rotatably coupled. with the barrel, plunger mounted in and movable longitudinally of said barrel and tip, said, tip having a rectangular bore, the plunger having a rectangular portion engaging the rectangular bore in the tip to key the tip and rectangular portion of the plunger against relative rotation, means for frictionally supporting a lead on. the rectangular portion of said plunger, the tip having a contracted reduced bore-end through which av lead. is adapted to pass, coop crating means on the barrel and plunger provid ing longitudinal movement of the plunger axially of said. tip upon relative rotation of the barrel and tip, said last named means comprising a nut portion on the barrel, and thread sections on said plunger operatively en aging said nut portion..

a. A mechanical pencil of the character described, comprising a barrel part and a tip end rotatably coupled With the barrel, a plunger mounted in and movable longitudinally of said barrel and tip, said tip having a, rectangular bore, the plunger having a rectangular portion engagon the barrel and ing the rectangular bore in the tip to key the tip and rectangular portion of the plunger against relative rotation, means for frictionally supporting a lead on the rectangular portion of said plunger, the tip having a contracted reduced bore-end through which a lead is adapted to pass, cooperating means on the barrel and plunger providing longitudinal movement of the plunger axially of said tip upon relative rotation of the barrel and tip, said last named means comprising a nut portion on the barrel, thread sections on said plunger operatively engaging said nut portion, and said nut portion constituting part of a sleeve interposed between the barrel and said tip.

5. A mechanical pencil of the character described, comprising a barrel part and a tip end rotatably' coupled with the barrel, a plunger mounted in and movable longitudinally of said barrel and tip, said tip having a rectangular bore, the plunger having a rectangular portion engaging the rectangular bore in the tip to key the tip and rectangular portion of the plunger against relative rotation, means for frictionally supporting a lead on the rectangular portion of said plunger, the tip having a contracted reduced bore-end through which a lead is adapted to pass, cooperating means on the barrel and plunger providing longitudinal movement of the plunger axially of said tip upon relative rotation of the barrel and tip, and said contracted bore end of the tip being split.

6. A mechanical pencil of the character described, comprising a barrel part and a tip part having a contracted end, the tip part hav ing a rectangular bore extending longitudinally throughout the major portion of the length thereof, said bore terminating at the contracted end of the tip in a small diameter lead guide bore, a plunger movable longitudinally of the barrel part, said plunger having a rectangular portion conforming with and fitting snugly in the bore of said tip to prevent relative rotary movement one with respect to the other, and cooperating means between the plunger and barrel for feeding the plunger longitudinally of the tip upon relative rotation of the tip and barrel.

FRANCIS M. AIMES.

No references cited.

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