US3458267A

US3458267A - Writing instrument

Info

Publication number: US3458267A
Application number: US679077A
Authority: US
Inventors: George G Larson
Original assignee: Eversharp Inc
Current assignee: Eversharp Inc
Priority date: 1967-10-30
Filing date: 1967-10-30
Publication date: 1969-07-29
Anticipated expiration: 1986-07-29

Description

y 9, 1969 5. G. LARSON 3,458,267

V WRITING INSTRUMENT Filed Oct. 50. we?

I INVENTOR GEORGE a. LARSON United States Patent U.S. Cl. 401213 9 Claims ABSTRACT OF THE DISCLOSURE A writing instrument characterized by a barrel forming elongated plastic tube having identical portions of reduced cross section at opposite ends thereof upon which a plug cover and a barrel nose, respectively, are received in telescoping relation, the plug cover being telescoped over the post forming hollow open end and having self-threading features so as to provide passageways between the inside wall of the plug cover and the post when the cover is screwed onto the post, which passageways lead to the exterior of the barrel through slots at the inner end of the cover and provide a vent forming passageway from the interior of the barrel, and the barrel nose having a ball point assembly mounted therein and a snap-on plastic cap.

This invention relates to writing instruments and is more particularly concerned with improvements in a pen structure of the ball point type which includes an open ended elongate ink containing barrel with special provisions for mounting a barrel nose and an associated ball point on one end of the barrel and a plug cover on the other end.

It is a general object of the invention to provide an improved ball point pen structure which can be economically produced for marketing at a relatively low price and which will operate in a satisfactory manner without clogging or drying out of the writing fluid.

It is a more particular object of the invention to pro vide a pen structure which comprises an elongate, open ended barrel forming an ink-containing member with the top forming end thereof vented through passageways between the walls of a hollow end post on the barrel and a telescoping cap, the latter having a self-threading screw on connection with the barrel end post.

It is a further object of the invention to provide a pen structure which comprises an elongated tubular barrel formed of plastic material and housing an ink supply with the barrel being open at the top forming end and having a hollow post which is of reduced diameter and on which a plug cover is screwed in telescoping relation and provided with vent forming passageways which extend to a recess formed in the inner edge thereof above a tapered shoulder at the top of the barrel and which open to the atmosphere.

Another object of the invention is to provide a pen structure which includes a barrel forming tube with end formations of reduced cross section which are identical and which enable a ball point assembly to be mounted on either end formation and a plug cap which may have self-threading, telescoping engagement with either end formation.

These and other objects and advantages of the invention will be apparent from a consideration of the pen structure which is shown by way of illustration in the accompanying drawings wherein:

FIGURE 1 is a perspective view of a pen which embodies the principal features of the invention, the pen being shown to an enlarged scale;

FIGURE 2 is an exploded elevational view to a still larger scale with the pen structure in partly disassembled 3,458,267 Patented July 29, 1969 ice condition, with portions broken away, and with the cap in cross section;

FIGURE 3 is a longitudinal section taken on the line 3-3 of FIGURE 2, to an enlarged scale, showing the screw-on plug cover structure;

FIGURE 4 is a longitudinal section taken on the line 4--4 of FIGURE 2 to an enlarged scale, with the cap Omitted; and

FIGURE 5 is a cross-section taken on the line 5-5 of FIGURE 2, to a still larger scale.

The pen structure 10 (FIGURE 1) which is illustrative of the present invention is a ball point type having an elongate tubular member forming a barrel 11 in which there is an axial compartment 12 (FIGURE 2) adapted to receive a suitable writing fluid. The barrel is symmetrical about a transverse axis and receives at one end a screw on plug cover 1 4 and at the other end the barrel nose 15 in which a writing ball assembly 16 is mounted. The nose 15 has a circumferential rib 17 for cooperation with an internal groove 18 in a cap forming member 26, the marginal portion of which is slit at 21 to provide the cap 20 with a snap-on feature. A spring metal clip 22 having a split mounting sleeve 23 is adapted to be adjustably positioned on the barrel 11 to complete the unit.

The barrel 11 comprises an elongate extruded plastic tube with an internal axial bore 12 forming an ink-receiving compartment. The ends of the tube are machined in an identical manner to provide relatively short lengths or

end portions

24 and 24 or reduced diameter which are connected to the main body of the tube at

external shoulders

25 and 25, the latter tapering in the direction of the longitudinal axis and the ends of the tube at an angle of approximately The barrel nose 15 which, in the illustrated form of the pen, is mounted on the barrel end portion 24, is formed of a suitable plastic with an axial bore 26 terminating at the inner or upper end in a tapered end edge 27 with the taper corresponding to that of the shoulder 25 on the barrel 11 so as to seat thereon, the external diameter at the inner end being less than the corresponding dimension of the barrel body so as to accommodate the cap 20. At the outer end of the nose -15 the bore 26 is reduced in diameter somewhat and tapers at 28 to an inwardly projecting circumferential rib 30 which is spaced inwardly a slight distance from the end of the nose. The bore 26 is provided with a plurality of axially extending ribs 31 for adjusting the fit when the nose is forced onto the barrel end formation 24. The external surface of the nose 15 is tapered somewhat inwardly in the direction of the point receiving end thereof.

The writing ball assembly comprises a metal body or point 32 of truncated cone shape with an axial bore and closed at the tip end by a writing ball 33 of suitable material and having a stem forming portion 34 at the other end. The stem portion 34 is adapted to telescope within the bore 26 of the barrel nose and has an external diameter corresponding approximately to or slightly greater than the internal diameter of the rib 30 SO that the latter fits snugly thereon and forms a ring seal on the stem 34 which prevents leakage.

The plug cover 14, which is formed of a material harder than that of the barrel 11, has an internal bore 35 (FIGURE 3) of greater diameter than the external diameter of the plug forming end section 24' on the barrel 11. The bore 35 is provided with a spiral thread formation 36 of the self-cutting type which enables the cover to be screwed onto the plug 24' and to cut a cooperating thread groove in the surafce of the latter upon initial assembly. The bore 35 is closed at the outer or upper end and at the inner end terminates at the inner edge of a tapered end surface 37 which is adapted to seat on the shoulder 25'. A plurality of circumferentially spaced, relatively shallow venting slots 38 are provided in the surface 37 so as to connect the spaces between the thread formations with the exterior of the pen and provide a passageway from the interior of the barrel 11 to the atmosphere outside of the same. The plug cover 14 has an external rib 40 for cooperation with the' internal groove .18 on the cap member 20 so as to hold the cap on that end of the pen when the point is uncovered for use and the cap 20 is telescoped over the plug cover 14.

The cap 20 is formed of resilient plastic or the like with the margin at the open end slotted at 21 to provide a series of spring fingers having an internal group 18 for snap-on engagement with the external shoulder or rib 17 on the barrel nose 15 and the rib 40 on the plug cover 14. A plurality of radially and axially extending, circumferentially spaced rectangular rib formations 41 of relatively short length are provided at the bottom of the cap which form a seat for the point 32 with the length of the ribs 41 being such as to limit the axial movement of the cap 20 by engaging the end of the plug cover 14 when it is placed thereon and the rib 40 is engaged in the groove .18.

While particular materials and specific details of construction have been referred to in describing the form of the pen structure which is illustrated, it will be understood that other materials and different structural details of an equivalent nature may be resorted to within the spirit of the invention.

I claim:

1. A writing instrument comprising an elongate barrel for housing a writing fluid with the upper end thereof open, said barrel having a portion at its upper end with a reduced cross sectional dimension so as to provide a hollow post formation extending from an external shoulder at the upper end of said barrel, and a plug cover adapted to telescope over said post formation, and said plug cover having an internal thread formation for cutting a cooperating thread groove in said post formation when screwed thereon and providing connecting passageways which are in communication with the interior of said hollow post formation and the exterior of the pen so as to form a vent for said barrel when said plug cover is seated against the external shoulder on the barrel.

2. A writing instrument comprising an elongate barrel for housing a writting fluid, said barrel being characterized by a section of relatively rigid plastic tubing having at its opposite ends substantially identical portions of reduced diameter constituting post formations which are joined to the body of the tube by external shoulder formations, a plug cover recessed to enable it to be telescoped over either one of said end post formations so as to close the one end of the barrel, said plug cover having internal means for connection with said end post formation and forming passageways which are in communication with the interior of said end post formation and the exterior of the pen so as to form a vent for said barrel, a barrel nose also recessed to telescope over either one of said end post formations and having a pen point assembly mounted therein with axial passageways connecting the pen point with the interior of the barrel for passage of the writing fluid.

3. A writing instrument comprising an elongate barrel for housing a writing fluid, said barrel being characterized by a section of relatively rigid plastic tubing having at its opposite ends portions of reduced diameter constituting post formations which are joined to the body of the tube by external shoulder formations, a plug cover adapted to telescope over either one of said post formations so as to close the one end of the barrel, said plug cover having passageways which are in communication with the exterior of the pen so as to form a vent for said barrel, a barrel nose also adapted to telescope over either one of said post formations and having a pen point assembly mounted therein with passageways connecting the pen point with the interior of the barrel for passage of the writing fluid, and said plug cover having an internal bore which is of greater diameter than the external diameter of the post formation and a thread formation in said bore which is adapted to cut a cooperating thread groove on the post formation when screwed thereon.

4. A writing instrument as set forth in claim 3, and said plug cover having its inner end seated on the external shoulder formation where the post formation joins the body of the tube and having recesses in said inner end forming part of said venting passageways.

5. A writing instrument as set forth in claim 2, and said plug cover having an internal bore of greater diameter than the external diameter of said post formation and a male thread formation in said bore which is arranged to cut a cooperating female thread formation on said post formation when screwed thereon, and said thread formations providing when engaged passageways between the inner wall of the plug cover and the outer wall of the post formation which cooperate with slots in the end edge of said plug cover to form the vent for said barrel.

6. A writing instrumentas set forth in claim 2 and said pen point assembly including a truncated cone shaped body with an axial stem formation extending at the larger end which has a cross sectional diameter less than the internal diameter of said barrel nose and telescopes Within 'the outer end of the barrel nose and said barrel nose having an internal shoulder adjacent the outer end thereof which snugly engages in sealing relation the outer surface of said stem formation.

7. A writing instrument as set forth in claim 2 and said barrel nose having an axial bore which is somewhat larger in diameter than the external diameter of the end post formation on the barrel, and axially extending internal ribs in the bore of said barrel nose which engage the external surface of the end post formation so as to insure a tight fit upon assembly.

8. A writing instrument comprising an elongate barrel for housing a writing fluid with the opposite ends having a plug cover and a barrel nose and point assembly, respectively, a snap-on cap having the margin at the open end slotted and provided with an internal groove for selective snap-on engagement with cooperating external ribs pro vided on the barrel nose and the plug cover respectively, and said cap having axially extending, circumferentially spaced ribs in the closed end thereof which provide a seat for the point when the cap is telescoped over'the barrel nose.

9. A writing instrument as set forth in claim 8 and the axially extending ribs in the closed end of said cap being of relatively short length with abutment forming inner ends which are spaced from the end so as to limit the axial movement thereof when the cap is telescoped over the plug cover. and the rib on the cover is engaged in the groove in the cap.

References Cited UNITED STATES PATENTS 2,505,211 4/1950 Schiesel 40l-2l7 2,823,403 2/1958 Whitney 4O l213 2,923,957 2/ 1960 Gentile 401-213 3,282,254 11/1966 Malrn et a]. 401-2l7 FOREIGN PATENTS 484,985 9/ 1953 Italy.

LAWRENCE CHARLES, Primary Examiner