US3397938A - Absorbent nib writing device - Google Patents

Description

Aug. 20, 1968 D. Jur-:1.55

ABSORBENT NIB WRITING DEVICE Filed Feb. s, 196e .QR w @l INVENTOR DAV/D JUELSS 8V @ya MM Q A TORNEY United States Patent O 3,397,938 ABSORBENT NIB WRITING DEVICE David Juelss, Brooklyn, N.Y., assignor, by mesne assignments, to Walter E. Heller & Company, Inc., New York, N .Y., a corporation of Delaware Filed Feb. 8, 1966, Ser. No. 525,993 2 Claims. (Cl. 401-198) ABSTRACT F THE DISCLOSURE This invention is directed to a marking pen in which the tapered tip section of the ybarrel is fitted with a snap-in nib-containing adapter positioned within an axial bore of the tip and is provided with an annular shoulder intermediate its ends, abutting the end of the tip section, and a shallow compressible annular bead that abuts an internal annular shoulder of the tip to lock the nib adapter in place. A threaded cap covers the nib end of the pen and serves as an outer seal, while a deep skirted thin-Walled internal fitting carried within the cap is frictionally engaged over the tip section to form an inner seal.

The invention This invention relates to new and useful improvements in fluid ink writing devices and more particularly seeks to provide a novel marking pen having an improved absorbent nib construction and a sealing device carried within the cap to prevent drying of ink through the nib when the marking pen is not in use.

Marking pens consist essentially of an ink reservoir and a projecting felt or nylon filament wick of uniform cross-section. Such pens in the past have been subject to certain deficiencies such as a tendency for the wicks or nibs to be driven back into the reservoir during use and for the ink either to dry on the nib or to evaporate too rapidly when not in use, due to inadequate sealing against exposure to the open air.

Marking pens constructed in accordance with this invention overcome those deficiencies and provide other improvements as well.

Therefore, an object of this invention is to provide a marking pen including a barrel having an external sealing abutment and a screw-on cap adapted to be brought into sealing enga-gement with the barrel abutment and being provided with an internal seal adapted to snugly engage that portion of the barrel enclosed by the cap.

Another object of this invention is to provide a marking pen of the character stated that includes a novel nib construction and a mounting adapter therefor.

Another object of this invention is to provide a marking pen of the character stated in which the nib includes a tip portion of relatively large diameter firmly seated in a recess in its mounting adapter and a long stem portion passing through an axial bore in the adapter and having a diameter substantially less than that of the tip portion.

Another object of this invention is to provide a marking pen of the character stated in which the nib is fabricated from molded plastic and in which the 'writing or marking characteristics can be predetermined by properly selecting the type of plastic and the size of its -beads and porosity to be molded.

A further object of this invention is to provide a marking pen of the character stated which is of all plastic construction except for the cap and clip which can optionally be made of other materials such as metal.

With these and other objects in view, the nature of which will become more apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.

3,397,938 Patented Aug. 20, 1968 In the drawings:

FIG. 1 is a longitudinal section of an assembled marking pen constructed in accordance with this invention;

FIG. 2 is a fragmentary longitudinal section showing a chisel type nib;

FIG. 3 is a fragmentary longitudinal section showing a modified form of nib adapter; and

FIG. 4 is an end elevation of the adapter of FIG. 3.

Referring to the drawings in detail, the invention as illustrated is embodied in a marking pen fabricated from molded plastic and includes an elongated Ibarrel S provided at its open end with a cylindrical recess 6 into which is fitted the cylindrical end `of a tapered tip section 7 having a shoulder 8 which abuts against the end of the barrel. A tight fit is assured either by adhesive or by friction or ultrasonic welding so that the barrel and tip section become, in effect, an integral unit. The tip section 7 carries a core 9 of ink-absorbent material that extends into the barrel 5 and terminates adjacent the closed end thereof and serves as an ink reservoir,

The tapered end of the tip section 7 is provided with an axial bore for receiving and retaining a snap-in nib adapter generally indicated 10` which includes a cylindrical -body 11 that fits in the bore of the tip section and is provided at its inner end with a shallow compressible annular bead 12 that engages with the face of the tip section at the inner end of the fbore. The nib adapter is also provided with an abutment shoulder 13 that mates with a corresponding shoulder formed on the end of the tip section 7.

The free end of the adapter 10 is provided with an axial recess having a generally frusto-conical base which together `define a nib seat extending into open communication with an axial Ibore 14 having a diameter substantially less than that of the axial recess.

A preferred form of nib for normal writing or marking is clearly shown in FIG. l of the drawings and includes a stem 15 having a diameter slightly less than that of the bore 14 of the adapter sufficient to provide capillary ow of ink toward the tip end and a length sufficient to extend from the base of the nib seat to a position where a portion of the stem is embedded in the adjacent end of the ink reservoir 9 which is cellulose acetate or similar cellulose material. The other end of the stem terminates in an enlarged portion 16 configured to closely conform to the shape of the nib seat and is provided at its outer end with a conical tip 17. This large terminal diameter end provides greater strength to resist angular pressure and further increases desk life by creating a reserve reservoir at the tip so that quick start-up is provi-ded even after long periods of non-use. Both the nib 17 and tip 10 provide easy assembly by merely forcing them into the end of the unit from the outside.

Nibs constructed in accordance with this invention are preferably fabricated from molded fluorocarbons, e.g., Teflon (Du Pont trademark for polytetrafluoroethylene) for fine writing or from molded polyethylene for soft smooth medium writing, although other plastics also may be used.

Writing characteristics of the finished nibs are determined in advance by such things as selection of the type of plastic, the size of the plastic beads used for molding and the density and porosity of the ultimate molded plastic. It is, of course, necessary that the plastic produced be of a generally porous or foraminous nature, i.e., have contiguous ow spaces, to provide for the capillary flow of ink therethrough.

It will be appreciated that since the stem 15 of the nib is smaller in diameter than the enlarged portion 16 and the enlarged portion 16 is firmly engaged within the nib seat, it is impossible for the niby to be driven back into the body of the adapter under conditions of use.

Also, it should be noted that uniform controlled flow of ink from the reservoir to the tip 17 is effected through the use of nibs and adapters produced in accordance with this invention.

The tip section 7 is provided with the usual vent 18 to assure a smooth flow of ink and to automatically compensate for temperature or pressure changes in the atmosphere both within and without the pen.

, A screw cap generally indicated 19, having the usual metal clip 20, covers the nib end of the marking pen when not in use and its normally open end lits closely around a portion of the barr-el and abuts against a shoulder 21 formed on the outside of the barrel to form a tight outer seal.

A tight inner seal between the cap and the tip section 7 is effected through the use of a titting generally indicated 22 formed from a molded tlexible plastic such as polyethylene. The tting 22 is provided with a thick end 23 having a shallow annular bead 24 frictionally engaged with the inner surface of the cap to securely retain it in position. A deep skirt 25 having tapered wall thi-cknesses extends from the end 23 and terminates in a thin end portion 26 having a near feather edge. The length of the skirt 25 is such that when the screw cap 19 is fully engaged over the barrel 5 the thin end portion 26 has become frictionally engaged with the outer surface of the tapered tip section 7 and has been slightly ared thereby to form a tight inner seal to prevent ink from drying on the nib and to cover the vent 18.

The inner seal is a very important aspect of the invention alone or in combination with the outer seal to make a double seal. The exibility of the inner seal makes it particularly effective in preventing ink evaporation.

In FIG. 2 of the drawings there is illustrated another form of nib having a chisel-type tip 27, instead of the conical tip 17, for use where broad writing, coloring or underlining is desired. In this style of nib it is preferable to use molded polyethylene in its fabrication although other plastics may also be used. The nib is shown abutting the felt reservoir 29 rather than penetrating as shown in FIG. 1, because generally the felt is diicult to penetrate.

An alternate venting arrangement is shown in FIGS. 3 and 4 of the drawings in which the nib seat portion of the nib adapter is provided with a plurality of longitudinally extending grooves 28 formed around the periphery thereof and extend into open communication with the axial `bore of the adapter.

It is, of course, to be understood that variations in arrangements and proportions of parts may be made within the scope of the appended claims.

-I claim:

1. In a marking pen; a barrel containing an ink reservoir and having a tapered tip section provided with an axial nib adapter-receiving bore terminating at its inner end in an annular abutment shoulder; and a snap-in nibcontaining adapter positioned within said adapter-receiving bore and having an annular shoulder intermediate its ends and abutting the end of said tip section and a shallow compressible annular bead adjacent its inner end and abutting the inner shoulder of said adapter-receiving bore whereby to securely lock said nib adapter in place; said nib adapter being provided with a nab seat defined by a distal axial recess extending into open communication with a proximal axial bore having a diameter less than that of said axial recess; said unit adapter also being provided with a contiguously process molded plastic nib 'fitted within said nib seat and being provided at one end with a tip projecting beyond the associated end of said nib adapter and at its other end with a steam having a diameter suiciently less than the diameter of said proximal axial bore to provide a capillary space therebetween and a length suicient to be operatively associated with an ink reservoir contained within said barrel.

2. The marking pen of claim 1 additionally including a cap enclosing said nib-containing end of said tapered tip section and threadably engaged over said barrel to form an outer seal, said cap being provided with a deepskirted internal fitting having a thin-walled open end frictionally engageable over said tapered tip section whereby to form an inner seal around the nib-containing end of said tapered tip section.

References Cited UNITED STATES PATENTS 2,782,438 2/ 1957 Wittnebert et al. 15--537 XR 3,145,412 8/1964 Levy l558l XR 3,233,275 2/1966 Hansen et ai. 15-563 3,278,976 10/1966 Ward 15--563 FOREIGN PATENTS 416,295 9/ 1934 Great Britain.

494,991 ll/ 1938 Great Britain.

985,592 3/ 1951 France. 1,3 84,182 11/1964 France.

ROBERT W. MICHELL, Primary Examiner.

UNITED STATES PATENT GFFICE CERTIFICATE OF CORRECTION `Patent No. 3,397,938 August 20, 196s David Juelss It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shovm below:

In the heading to the printed specification, lines 4 and 5, "Walter E. Heller Company, Inc. New York, N. Y.,

a corporation of Delaware" should read Venus Pen Pencil Corporation, New York, N. Y., a corporation of New York Column 4, line 2l, "steam" should read stem Signed and sealed this 13th day of January 1970.

(SEAL) Anest:

Edward M. Fletcher, J r. Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

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