US2460345A

US2460345A - Ball point pen

Info

Publication number: US2460345A
Application number: US636790A
Authority: US
Inventors: Francis E Gruber
Original assignee: Brown & Bigclow
Current assignee: Brown & Bigclow
Priority date: 1945-12-22
Filing date: 1945-12-22
Publication date: 1949-02-01
Anticipated expiration: 1966-02-01

Description

` INVENTOR FRANCIS E. GRUBER BY @i ,M44 TORNEY F. E. GRUBER BALL PO INT PEN Feb. 1, 1949.

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Patented Feb. 1, 1949 BALL POINT PEN Francis E. Gruber, St. Paul, Minn., assigner to 'i Brown et Bigelow, St. Paul, Minn.

Appunti@ December 22, 1945, serial No. 636,790

' This invention relates to a fountain pen Wherein the rink used therein is of a, viscousfnature and tends to travel through the ink chamber by capillary. attraction tothe writing tip. The writing tip is in the form of'a ball which rotates in a socket. The viscous ink is picked up by the writing ball and carried by capillary attraction from the reservoir onto the ball and from the ball to the surface on which the pen is writing.

A feature resides in providing` aunit ink reservoir of a tubular nature, the body of the reservoir being in the form of helical coils of hollow tubing and to the forward end of the unit I attach the writing. endof the pen which supports the ball bearing freely rotatable inY a socket on" the extreme outer end of the unit.

A feature resides inproviding a fountain pen with a replaceable ink chamber unit and writing end which are connected=together as a complete unit and which may be replaced with a new unit whenever it is desired. The ink used in my pen is not of the freely iiowing type like that ordinarily used in fountain pens employing a pen point. The ink is of a viscous nature with a surface tension so as to be attracted by capillary action causing the ink to travel toward the smaller opening in the chamber while atmospheric air is admitted to the larger or rear end of the unit. It is desirable that a complete volume of ink extend into the writing tip and it is irnportant that the ink contact the bali without air space between the ball and the ink. The iiow of the ink is limited by the surface tension and the ball acts to enhance the trave1 of the ink to the writing tip as the ink is used up in writing.

With a pen of this character, the writing cperation is smooth and free on all sides so that the pen may be rotated into any position. The writing of my pen may be characterized as being smooth and free like the writing with a pencil. The ball bearing writing tip rolls freely over the surface being written upon and discharges the ink onto the surface in a smooth line.

A feature resides in providing a propelling and repelling means for the ink unit and/writing tip which is adapted to be operated by rotating the rear end of the pen which operates a screw core member threaded to the inner surface of the coils of the ink reservoir and thus the ink reservoir and writing tip as a unit are propelled into writing position or withdrawn into the casing of the pen so as tc conceal the writing end of the pen without need of a cap for covering the writing end when the pen is not in use.

These features together with other details and 3 Claims. (ci. 12o-42.03)

' objects of the invention will be moreY fully. and

clearly hereinafter set forthinthe specification and claims.

Figure 1 illustrates a longitudinal section throughmypen. f I g Figure 2 is a similar view to Figure 1 with a portion ofthe pen 4casing broken away and a portion of the ink reservoir illustratedin section with the rear end of the pen. I

The pen A is formed with an outer casinghaving Aa removable writing tip H3, a barrel portion! i, and a rotatable end cap member it. The clip it is mounted on thecap i2 by thehead it which is threaded at i5 tothe cap l2. H

The head I2is adapted 4to be held rotatable -to the rear end of the barrel il by the spring sleeve it which operates between the collars carried by the head i2 and which provides a frictional engagement with the inner sleeve ll'in the rear end of the casing or barrel I I. j Y- a v/ The head l2 is provided with an extended core member i8 which is formed with threads i9 on the inner end of the same. The end it and the threads I 9 are rotated when the cap l2 is rotated. The cap l2 is formed with an elongated sleeve 2G which rotates with the cap and the clip I3 and at the same time the threads IS are rotated.

The ink reservoir unit B is formed by a hollow tubular member 2l which is formed with a series of coils 22, the forward end of the tube 2i is connected to the writing tip 23 and in the eX- treme forward end of the writing tip E3 I mount a ball bearing 2t which is the writing end of the unit B and which rotates freely in the writing tip 23.

The ink reservoir unit B is removable with the writing tip `23 and the ball 2B so that a new unit B may be inserted in the casing of the barrel ii whenever it is desired.

The hollow tubular reservoir B is adapted to be i'llled with a viscous ink having a surface tension which allows the ink to be extended through the small passageway 25 in the writing tip 23 to the ball 2t. When the unit B is filled with the ink the last two or three coils at the rear of the same are left empty to provide an air chamber in the rear end of the ink unit B which allows for expansion of the ink without the same oozing from the chamber. The rear end 26 of the coils 22 extends out longitudinally as illustrated in Figures 1 and 2 and is adapted to contact the rib 21 formed on the inner sleeve l'i to hold the unit B against rotation in the barrel l i. The threads I9 engage the coils 22 so that when the head I2 3 is rotated and the unit B is held against rotation by the rib 21, the entire unit B with the writing tip 25 and ball 24 is moved longitudinally for- WardV or backward Within the casing of the pen A.

When the writing ball 24 and the unit B are in the position illustrated in Figure 1, the pen A is in operative position with the ball 24 exposed out of the writing end I of the casing of the pen.

When the pen is not desired for `use the cap l2 may be rotatedk to operate the threads i 9 to draw the unit B into the barrel or casing of the pen A as illustrated in Figure 2. This operation conceals the Writing ball 24 in the tip lll.

The viscous ink used in my pen is of a nondrying nature, therefore a cap is not required for the pen, however, it is desirable that the pen ball 24 be drawn into the Vtip end 10 so as to protect the user of the pen from getting inl: onto articles when the pen is not in use.

The unit B is moved in its entirety with the writing ball 24`by turning Ythe cap l2k which causes the threads I S tomove the unit B forward or backward as may be desired. Figure 2 shows the unit B retracted into the barrel of the pen A and with the writing ball 24 protected Within the tip l0. The alternative form illustrated in Figure 3 shows the outer part of the tube 28 threaded at 29 so as to engage with the threaded collar 30 when the cap I2 is rotated.

I claim:

1. A fountain pen comprising an ink unit formed of a hollow tube, a series of coils formed inthe body of said ink reservoir adapted to provide the main part of the reservoir, a tubular ior- 4Ward end projecting Vas a-portion oisaid ink-unit, Va ball Writing tip mounted in the forward end of said ink reservoir unit, a casing for enclosingsaid unit and adapted to support the same 'slidable therewithin, a rotatable cap for the `rear of said casing, and a threaded core member operated by said cap to threadedly engage said ink unit to move the same longitudinally in said casing to conceal or expose said writing ball on the forward end of said ink reservoir unit.

2. A fountain pen including a casing, a replaceable ink unit, said casing being separable to permit a new ink unit to be inserted therein, said ink unit being formed of a hollow tube with the body portion thereof formedinto a series of helical coils positioned adjacent eachother, the rear end of said unit being open to the outer atmosphere, the forward end of said unit having a writing ball rotatably anchored therein, and means for moving said ink unit in said casing to expose and conceal said writing ball by a threaded engagement of said helical coils.

3. `A fountain pen including a casing, a removable ink unit supported within said casing, said ink unit being formed of a hollow tube, a series of coils formed in said tube adjacent each other to form the main Abody portion of said. unit, a writing ball bearing :anchoredon the forward ,end of said unit and threaded core means for engaging the rear of said unit to move said unit bodily backward or forward within said casing.

FRANCIS E. GRUBER.

REFERENCE S CIT ED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Great Britain Dec. 4, 1945