US 3918819 A
Writing implement comprising an outer barrel having a split clamp front end, an inner tube containing a plurality of bullet-like presharpened pencil leads having a ring grooved structure for clamping, a cap screwably mounted in front of the outer barrel to tighten or release the clamp end for holding steady the lead for writing, or to free the lead to be drawn out when the tip is dulled, or pushed into the tube to facilitate carrying. The rear half of the tube may be modified to form a ball pen refill tip, and the rear half of the barrel in turn having a conical shaped end to retain the ball pen tip. The inner tube may also be supported within the center aperture of a radial frame longitudinally disposed within the outer barrel, compartments being formed between radial elements of the frame serving as storage for spare leads.
Description (OCR text may contain errors)
United States Patent 11 1 Liu 1 1 NOV. 11, 1975 l l WRITING IMPLEMENT  lnventor: Hsing-Ching Liu, Taipei.
Taiwan  Assignee: Kent Industrial Corporation, Taipei.
Taiwan [22 Filed: Aug. 22, 1974 121 1 Appl. NO; 499,604
 ABSTRACT Writing implement comprising an outer barrel having a split clamp front end. an inner tube containing a plurality of bullet-like presharpened pencil leads having a ring grooved structure for clamping. a cap screwably mounted in front of the outer barrel to tighten or release the clamp end for holding steady the lead for writing. or to free the lead to be drawn out when the tip is dulled. or pushed into the tube to facilitate carrying. The rear half of the tube may be modified to form a ball pen refill tip. and the rear half of the barrel in turn having a conical shaped end to retain the ball pen tip. The inner tube may also be supported within the center aperture of a radial frame longitudinally disposed within the outer barrel. compartments being formed between radial elements of the frame serving as storage for spare leads.
5 Claims, 13 Drawing Figures U.S. Patent Nov. 11, 1975 3,918,819
WRITING IMPLEMENT FIELD OF INVENTION The present invention relates generally to a writing implement, and more particularly to a writing implement having supplied within an inner tube a plurality of pre-sharpened pencil leads, which are uniquely designed with a ring groove to be held tightly by a clamp formed in the front end of the outer barrel of the implement. The rear half of the inner tube may also be formed as a ball pen refill tip, to give the implement a dual purpose, both as a pencil and a ball pen.
BACKGROUND OF INVENTION Writing implements with pre-sharpened pencil lead such as disclosed in the US. Pat. No. 3,338,215 have been known to have a plurality of lead sections prefabricated by inserting the lead into a cartridge and arranging the cartridges in a barrel. When the case of one cartridge is finished, it is drawn out from the front end of the barrel and tucked into the rear end to squeeze out the tip of a new cartridge of lead next to the one just drawn away. This kind of pre-sharpened or so called non-sharpening pencil, although being one among the best sellers, still has several disadvantages. Firstly, to insert a short stub of pre-sharpened lead into a small cartridge is quite a labor consuming job. Even if an automatic insertion machine is devised, the loss in such a delicate work is high, thereby increasing the cost. Secondly, in case one of the cartridges is lost in the continuous route in the barrel, this would break the whole journal and makes the whole pencil inoperable.
The present inventor has devised the present invention to solve all these problems.
SUMMARY OF INVENTION Therefore, the main object of the present invention is to provide a writing implement with a plurality of ring grooved and pre-sharpened pencil lead stubs which are supplied freely and successively in an inner tube within an outer barrel, whereby with the aid of a split clamp construction at the front end of the barrel actuated by a protruded portion inside an aperture of a cap front there is effected easy clamping and releasing of the lead in the frontmost position without any inference to any other stubs in the tube, once the frontmost dull stub being drawn out, the stub next to it falling freely into position.
Another object of the present invention is to provide a writing implement wherein the said lead stubs are inserted directly into the said inner tube without first having to be pre-fabricated into cartridges, thus eliminating much work and lowering the cost of the implement.
Still another object of the present invention is to provide a writing implement wherein the rear half of the inner tube is formed as a ball pen refill, and the rear half of the barrel becomes a ball pen to provide a dual BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows an exploded perspective view of the outer barrel of a preferred embodiment of the writing implement of the present invention;
FIG. 1A is a longitudinal sectional view showing the detail of the implement in FIG. 1;
FIG. 2 is a longitudinal sectional view of the inner tube of the said implement;
FIG. 3 is a longitudinal sectional view of an inner tube of another embodiment showing the rear half of the tube being a ball pen refill;
FIG. 4 shows a perspective view of the rear end of the outer barrel when the inner tube in FIG. 3 is being adopted;
FIG. 5 shows a longitudinal sectional view of a writing implement serving both as a pencil and a ball pen; FIG. 5A is a modification of the implement in FIG. 5;
FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5A;
FIG. 7 is a cross-sectional view taken along line VII- VII in FIG. 5A;
FIG. 8 is a cross-sectional view taken along line VIII- VIII in FIG. 5A;
FIG. 9 is a sectional view showing the detail of the split clamp in the front end of the barrel;
FIG. 10 is a sectional view showing the cap of the barrel being unscrewed to release the pencil stub in the frontmost position; and
FIG. 11 is a sectional view showing the cap of the barrel being screwed up to cause the clamp to hold tight the lead stub.
DETAILED DESCRIPTION OF EMBODIMENTS Now referring to FIG. 1, the outer barrel of the writing implement of the present invention comprises a barrel 1, a front cap 2, and an eraser assembly 3. The barrel 1 has a cylindrical wall 11, a split clamp formation 12 in the front end, and a male thread 13 for screwing together with a female thread 23 formed at the rear end of the cap 2. The eraser assembly 3 has at its front end a male thread 31 to be fitted into a counter part female thread 14 formed at the rear end of the barrel 1. The eraser retainer 3 has recess 32 to receive an eraser 33 at its rear end.
In FIG. 2 the inner tube 4 has a tubuular wall 41 with bullet-like lead stubs 42 filled therein. In FIG. 1A, the longitudinal sectional detail shows the tube 4 of FIG. 2 being installed within the barrel 1. Referring also to FIG. 5A and FIG. 7, a modification of FIG. 1A is shown wherein the inner tube 4 is retained inside the barrel wall 1 1 within the center aperture 151 of a radial frame work 15 which is longitudinally disposed in the barrel through the full length. Spare lead stubs 42 are stored within the compartments formed between radial elements 152 of the frame 15 and are charged and discharged through rear screw end 14 of the barrel 11.
In FIG. 3 as an alternative the inner tube 4' has its rear half formed into a ball pen refill with a tube wall 41a, ink 43, and a tip 44. The middle of the inner tube 4 is stamped as at 45, to seal the ink in tube 41a. The rest of tube 4 is filling with lead stubs 42. In this case the eraser retainer 3 is not used, and instead the rear end of the barrel 5, as shown in FIG. 4, is screwed on the front half of the barrel 1 by means of thread couple 14-52. The rear end of barrel has a wall 51 and rear aperture 54 to receive the ball pen tip 44.
In FIG. 5A, another embodiment for the ball pen refill is shown. The refill 4la is enlarged in its diameter to hold more ink 43, and is formed separately from the tube 41. The refill 41a is retained on a disc seat 53 in the middle of the barrel where screw threads 14-52 are joined. The cross-section of this part is shown in FIG. 8.
Now, for details of the clamp and cap portions refer to FIGS. 1, 5 and 9. Cap 2 has a conical wall 21 which is not in close contact with clamp wall 12, and a front aperture 22. After cap 2 is screwed onto the barrel 1 by means of thread couple 23-13, the frontmost lead stub 42 will be held tightly by clamp 12 which is actuated by the protruded portion 22a around the inner circumference of aperture 22. The lead tip 421 protrudes out through opening 124 and aperture 22 of the cap. The detailed cross-section of this is shown in FIG. 6.
In FIG. 1, the clamp 12 split is extended as shown at 111. The details of the lead stub 42 and clamp 12 are shown in FIG. 9. The bullet shaped lead stub 42 has a tip 421, a ring groove 422, a rear portion 423, and a base 424. The clamp 12 has a front aperture 124. A projection 123 grips in the ring groove 422 of the lead stub 42. Recess 122 is provided to receive the rear cylindrical portion 423 of the lead stub 42, and a protruded portion 121 retains the base 424 of the lead stub 42. FIG. 9 shows the clamped position.
In FIG. 5, the rear portion of the clamp 12 can be seen. A recess 112 is formed to accept the front end of the tube wall 41. In FIG. 5A, this is further modified in that, around the front end of the tube wall 41, a conical cushion member 113 is provided having its rear end meeting the tips of the stored spare lead stubs 42.
FIGS. 10 and 11 shows, respectively, the releasing and clamping of the clamp when the cap 2 is being screwed loose in FIG. 10 and screwed tight in FIG. 11. Note especially that the protruded inner portion 22a actuates the opening and closing of the clamp 12, instead of wall contact between 21 and 12, so that with the unscrewing just a little bit of the cap 2, the lead 42 is capable of being freely withdrawn.
In using the implement, when the rejection of a dull frontmost lead stub or retraction of the frontmost lead stub to facilitate carrying is desired, hold the implement vertically with the stub tip down and just screw the cap 2 loose. The clamp 12, being made of material such as plastic of resilient property opens naturally to permit the drawing out or pushing in of the stub as shown in the FIG. 10. While in use, the cap is screwed tight to cause the jaw of the clamp to be closed to hold the stub steady.
The above embodiments serve only for illustrative purpose and not by way of limitation, and modifications will become evident to those skilled in the art which will fall within the scope of the attached claims.
1. Writing implement comprising an outer barrel hav- 7 ing a split clamp front end, an inner tube mounted inside the barrel having a plurality of pencil lead stubs therein, each lead stub having a bullet-like body with a tip in front and a ring groove around it and a base, the said clamp end of the barrel having a projection portion in front to engage with the ring groove of the lead stub, the clamp end of the barrel being enclosed by a cap screwed on the barrel, an aperture in front of the cap for the projection of the tip of the frontmost lead. stub in said tube, a protruded portion formed on the inner circumference of the said aperture and disposed to contact the outside clamp wall, whereby when the cap is screwed tight the protruded portion actuates the barrel clamp end to grip the frontmost lead stub for writing and when the cap is screwed loose it permits the barrel clamp end to free the frontmost lead stub for rejection from and retraction into the barrel without hampering the lead adjacent to it. I
2. Writing implement according to claim 1, wherein the rear half of the inner tube comprises a ball pen refill, and the outer barrel comprises front and rear ends threaded together, the rear end of the barrel having a conical end with an aperture through the center to hold the ball pen refill end of the inner tube, whereby said implement is usable both as a pencil and a ball pen.
3. Writing implement according to claim 1, wherein. behind said tube is disposed a separate tube having a larger diameter than the first said tube for holding ink, said separate tube being retained in the outer barrel on a disc seat.
4. Writing implement according to claim 1, wherein the clamp end also has a recess to receive the rear portion of the lead stub and a protruded portion to retain the base of the lead stub to prevent the lead stub from retreating, the rear portion of the clamp end having a recess to accept the front end of the tube wall.
5. Writing implement according to claim 1, wherein.
the inner tube is mounted through a center aperture of a radial frame having radial elements longitudinally disposed in the barrel, compartments being formed between the radial elements of said frame for storage of spare lead stubs, and a conical cushion member is provided at the rear end of the clamp end to meet the tips of the spare lead stubs.