US3477792A

US3477792A - Retractable marking pens

Info

Publication number: US3477792A
Application number: US688162A
Authority: US
Inventors: Sidney X Shore
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-12-05
Filing date: 1967-12-05
Publication date: 1969-11-11
Anticipated expiration: 1986-11-11

Description

Nov. 11, 1969 s. X. SHORE RETRACTABLE MARKING PENS Filed Dec. 5, 1967 United States Patent 3,477,792 RETRACTABLE MARKING PENS Sidney X. Shore, 29 Wren Drive, Roslyn, N.Y. 11576 Filed Dec. 5, 1967, Ser. No. 688,162 Int. Cl. B43k 5/16 U.S. Cl. 401-109 6 Claims ABSTRACT OF THE DISCLOSURE A retractable pen includes a cartridge having a bundle of filaments ending in a writing tu-ft. A tube contains the bundle of filaments. The tube is of one diameter where it is slidably guided in a bore at the writing end of the pen barrel. Adjacent the writing tuft, the tube has a reduced diameter portion whose length is several times its diameter. The construction accommodates spreading of writing fluid on the reduced-diameter portion of the tube without danger of transfer to the pen barrel when the writing tip is retracted.

The present invention relates to pens of the so-called marking pen type, and more particularly to retractable marking pens.

For many years, so-called markers have been available for making broad marks, especially signs. Markers have an ink container in the handle, a felt writing wick, and a cap. Compared to usual pens, markers make a very broad line. In recent years markers have been devised having a small bundle of durable filaments as the writing point, such as nylon filaments. As a result, markers have become marking pens. The line made by such a pen is but little heavier than the usual line of a ballpoint pen or a fountain pen.

Marking pens use a form of fluid that reaches the writing tip from a reservoir by capillary action. The reservoir ordinarily cannot be replenished with marking fluid by the user. When the supply of marking fluid is exhausted, the pen is discarded, or, in case the pen has a replaceable refill or cartridge, the refill is replaced when the fluid supply is gone.

Marking pens that used replaceable refills have been available in the retractable form, so that the writing tip can be shifted to a safe position within the pen barrel. The intention is to enable the user to put the pen in his pocket, often the breast pocket of a shirt, without marking the shirt. Unfortunately, only a limited amount of fluid can be loaded into the reservoir of a retractable marking pen, compared to markers that use a protective cap over the writing tip. This is because the fluid often tends to accumulate externally near the writing tip and spread about the tube that supports the porous or multifilament tip. Then, when the tip is retracted, any marking fluid that did spread to the guide tube would be wiped off by the tip of the pen barrel. The tendency of the fluid to spread in this way is avoided by sharply limiting the amount of fluid in the reservoir. Accordingly, the refill must be replaced much sooner than would be needed were there an ample amount of fluid in the reservoir.

An object of the present invention resides in providing an improved retractable marking pen minimizing the foregoing difficulties. More particularly, it is an object of the invention to provide a novel form of retractable marking pen having an ample supply of marking fluid, virtually eliminating the danger of transfer of marking fluid to the tip of the barrel.

In the illustrative embodiment of the invention described in detail below, the writing end of a refill is formed with a tube of limited cross-section to contain 3,477,792 Patented Nov. 11, 1969 the bundle of marking filaments and provide a projecting writing tuft. A larger diameter tube supports the writing end of the refill and is slidably guided in the barrel of the pen. The end portion of the marking pen that is of limited cross-section is several times as long as it is thick. The larger diameter portion provides firm lateral support for the writing end portion of the cartridge, so that the desired pressure can be applied to the writing tip. However, there is clearance from the barrel about the end portion of the refill, and consequently, when the cartridge or refill is being retracted, there is virtually no danger of smutting the end of the barrel with marking fluid.

The nature of the invention including the foregoing objects, novel features and advantages, and others, will be better appreciated from the detailed description of the presently preferred embodiment of the invention shown in the accompanying drawings.

In the drawings:

FIGURE 1 is a lateral view of the presently preferred embodiment of the invention, portions being broken away and shown in cross'section; and

FIGURE 2 is a lateral fragmentary view of a conventional retractable marking pen shown partly in crosssection.

In FI'G. 1, a novel retractable marking pen is shown having a barrel 10 that contains a cartridge or refill, and slidably receives tubular guide portion 12 of the cartridge. Spring 14 biases the cartridge to the retracted position shown. An operating mechanism of any desired conventional design is contained in the upper end 16 of the barrel, and is operable (for example) by pressing button 18 repeatedly. Writing tip 20 is alternately projected to its Writing position (dotted lines) and to its retracted position, in which the Writing tip assumes a protected position within the barrel.

An end portion 22 of the cartridge is a tube, preferably of metal, that tightly contains a bundle of capillary filaments 24 as of nylon, these filaments extending through the larger-diameter tube 12 and into a reservoir 26 of writing fluid. The reservoir may also contain capillary packing.

End portion 22 is a cylinder whose length at least equals its outside diameter, but preferably it is several times its diameter in length. It is at least a few thousandths of an inch smaller in diameter than guide portion 12. Marking fluid in limited amounts may spread onto the reduced-diameter end portion 22 of the cartridge, and yet there is no danger of marking fluid reaching the barrel because of the clearance space between end portion 22 of the cartridge and the slide passage in the barrel.

This construction contrasts with the conventional form of retractable marking pen in FIG. 2, wherein like parts corresponding to those in FIG. I bear corresponding primed numerals. The lower portion 22 of the cartridge is slidable in the bore of barrel 10'. Because of the sliding fit, any coloring that may spread from the writing tuft 20' to the lateral surface of lower portion 22' of the cartridge will be scraped off by barrel. 10'. The coloring thus deposited at the tip of barrel 10 tends to stain clothing. For example, when the marking pen is being put into a shirt pocket of a user, the shirt would be stained by the fluid collected at the tip of barrel 10. All this is avoided in the marking pen of FIG. 1, described above, and yet the performance is not impaired in any way.

Changes in the above-described embodiment of the invention may readily be introduced by those skilled in the art, in such a manner as to utilize the novel concepts above; and therefore it is appropriate to construe the invention broadly in accordance with its full spirit and scope.

What is claimed is:

1. A retractable marking pen including a barrel, a cartridge in said barrel having an extended Writing position and a retracted storing position, said cartridge having a reservoir containing marking fluid and fixed means forming a writing tip having numerous capillary passages therethrough extending from the reservoir, said barrel having a cartridge guiding bore at one end thereof and said cartridge having a tubular guide portion near said writing tip that is slidably guided in said bore, said cartridge having an end portion extending from said tubular guide portion and supporting said writing tip, said end portion being of substantial length and of lesser crosssection than said guide portion so that said end portion of the cartridge has a clearance space around it in the retracted position of the cartridge for avoiding transfer of writing fiuid to the tip of the barrel from the portion of the cartridge adjacent to said writing tip.

2. A retractable marking pen in accordance With claim 1 wherein said end portion of the cartridge is of uniform cross-section and has a length 'at least equal to its diameter.

3. A retractable marking pen in accordance with claim 1 wherein said writing tip is the tuft of a bundle of filaments extending from said reservoir.

4. A retractable marking pen in accordance with claim 1 wherein said writing tip is the tuft of a bundle of filaments extending from said reservoir, and wherein said end portion of the cartridge is a tube whose outside diameter is smaller than the diameter of said guiding portion of the cartridge and said end portion having a length at least equal to its diameter.

15. A retractable marking pen in accordance with claim 1 wherein the length of said end portion of reduced crosssection exceeds greatly its transverse size.

6. A retractable marking pen in accordance with claim 1 wherein said writing tip is the tuft of a bundle of filaments extending from the reservoir, and wherein said end portion of reduced cross-section is considerably greater in length than in its transverse size.

References Cited UNITED STATES PATENTS 3,203,025 8/1965 Schreur 401 19s X 3,361,516 1/1968 Rigondaud 401-198 X FOREIGN PATENTS 1,485,772 5/1967 France.

LAWRENCE CHARLES, Primary Examiner U.S. C1.X.R.