US2734484A

US2734484A - Ball point pen

Info

Publication number: US2734484A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb. 14, 1956 J. F. O'SULLIVAN 2,734,484

BALL POINT PEN Filed July 11. 1952 INKENTOR. JbMVA'OJUu/VAA/ BALL POINT PEN John F. OSullivan, Los Angeles, Calif., assiguor to Frawley Corporation, Culver City, Calif., a corporation of California Application July 11, 1952, Serial No. 298,377

Claims. (Cl. 120-42.!)3)

My invention relates generally to writing instruments, and more particularly to a retractable type of ball point pen.

By reason of the ball nose assembly, and the character of the ink used, a ball pointed pen is not susceptible to leakage as is the conventional fountain pen. Furthermore, only the very small outer surface of the ball is covered with wet ink, and may be easily protected by retraction within the pen barrel. For these reasons it is feasible to construct a ball pointed pen with a slidable writing cartridge movable from an extended writing position to a retracted carrying position. This avoids the use of the inconvenient separate cap found on conventional pens, simplifying the construction, and providing a pen which is instantly ready for use.

This invention is concerned with a direct and positive acting operating mechanism for moving the writing cartridge between carrying and writing positions. In general, prior types of operating means have involved complex mechanisms which are subject to frequent breakdowns, and have numerous intricate parts which are expensive to manufacture and diflicult to assemble. An embodiment of my invention has a minimum number of direct acting elements cooperating in such a manner that it is impossible for the pen to jam or skip. The elements are economical to manufacture, and so durable that the pen is substantially trouble-free. In addition, the complete mechanism is easily operated and quite convenient to use.

With the foregoing in mind, it is a major object of my invention to provide an improved retractable ball point pen of simple and durable construction.

Another object of my invention is to provide an improved pen of the class described having an operating mechanism which is conveniently used, and not subject to accidental or unintentional movement.

It is also an object of my invention to provide an operating mechanism having a positive and direct acting operating plunger for urging a writing cartridge into an exposed writing position.

A further object of my invention is to provide simple and positive locking means for holding the writing cartridge in extended position.

An additional object of my invention is to provide a side release button operable to withdraw the writing cartridge, and so disposed that it does not interfere with the use of the instrument nor is it subject to accidental release.

It is a still further object of my invention to provide an operating mechanism having a minimum number of working parts, permitting an easy and rapid assembly.

These and other objects and advantages of my invention will become apparent from the following detailed description of a preferred embodiment thereof, and from an inspection of the accompanying drawings, in which:

Fig. 1 is a side elevation partially in section of a preferred embodiment of my invention;

Fig. 2 is an enlarged partial section of the upper opnited States Patent'O" Patented Feb. 14, 1956 crating mechanism showing the writing cartridge in withdrawn carrying position;

Fig. 3 is a view similar to Fig.2 showing the operating plunger depressed;

Fig. 4 is an enlarged partial section of the operating mechanism showing the writing cartridge in extended position;

Fig. 5 is a cross-section taken along the line 55 of Fig. 4;

Fig. 6 is an inverted perspective view of the locking sleeve; and

Fig. 7 is a cross-section taken along the line 7-7 of Fig. 1.

Referring now the drawings and particularly to Fig. 1 thereof, the numeral 10 designates generally a pen housing or barrel formed as a tapered cylindrical member of conventional configuration. In order to permit installation and replacement of an internal writing cartridge 11, barrel 10 is preferably formed of two-part construction comprising a lower body 12 and an upper cap 13. Body 12 is provided with an enlarged axial chamber 14 having upper threads 15 to take a threaded hub 16 extended downwardly from cap 13. Extended through cap 13 is an axial chamber 18 of somewhat smaller diameter than chamber 14 and opening into the upper end of the latter.

Writing cartridge 11 is formed as an elongated tubular shell which extends through both

chambers

14 and 18 and carries on'its lower end a reduced stem 19 having a ball nose assembly 20 for engagement with the writing paper. The front end of body 12 is open to slidably receive stem 19 in a relatively loose fit, and is formed with an internal shoulder 21 which abuts against the end of the tubular shell of cartridge 11 and limits its outward extension. In this position, stem 19 is projected outwardly from body 12 to expose nose assembly 20 for writing, as shown in phantom outline. The lower intermediate section of cartridge 11 forms an ink reservoir which is in communication with nose assembly 20 through stem 19. As the ball of the nose assembly rotates, it picks up a thin film of ink from the interior of stem 19 and moves it outwardly for transfer to the surface of the writing paper.

Surrounding the lower portion of cartridge 11 is a spring means in the form of a coil spring 24 which is limited in downward movement by engagement at its lower end with the wall of chamber 14. The upper end of spring 24 engages a crimped projection 25 formed on cartridge 11 in such a position as to cause the spring to be compressed when the cartridge has moved downwardly to the writing position. Thus, spring 24 continuously urges cartridge 11 to retract upwardly to a carrying position in which nose assembly 20 is confined within body 12.

In order to move cartridge 11 downwardly to the writing position, I provide an upper operating mechanism which includes an operating plunger 26 having a head 27 which projects outwardly from the top of cap 13 for manual actuation. For ease of assembly I prefer to form cap 13 of built-up construction with a solid plastic core or insert member 28 press-fitted Within an outer metal cover 29. Insert 28 is terminated short of the top of cover 29, and defines an enlarged open space 30 which lies above the upper end of chamber 18. At one side of cover 29 is a spring pocket clip 31 which is secured firmly at its upper end to the wall of the cover, and has a downwardly projecting arm formed with the con ventional balled tip for attaching the pen to the fabric of a pocket, or the like.

Plunger head 27 is slidably fitted within a suitable opening formed in the top of cover 29, and upward movement of the plunger is limited by a stop collar 34 which lies within space 30 and is adapted to abut against the inner wall of the cover when the actuating head is in a raised position. The lower end portion of plunger 26 is slidably fitted within a locking sleeve 35 secured within the top of insert 28 so that the plunger is constrained for sliding movement along the longitudinal axis of the pen. A coil spring 36 surrounds plunger 26 and is seated between the upper end of sleeve 35 and stop collar 34 to urge the plunger upwardly with head 27 in an exposed position.

Extending the entire length of chamber 18 along one side thereof is an offset portion 37, as can best be seen in Figs. 4 and 5. The upper or rear end of offset por* tion 37 is terminated by the end wall of sleeve 35 which forms in effect an internally overhanging locking shoulder or projection 38. Offset portion 37 is smoothly joined to chamber 18 and is of such a cross-sectional size that cartridge 11 may shift laterally away from the axis of chamber 14 into a position beneath shoulder 38. The offset portion 37 may be said to impart an elliptical cross section to the chamber or cause the chamber and its offset portion 37 to be eccentric with respect to the axis of chamber 14 and the axis of the plunger 26. As was previously mentioned, cartridge stem 19 has a relatively loose fit within the lower end of body 12, permitting the top of cartridge 11 to rock freely toward or away from the axis of chamber 18. The external diameter of cartridge 11 is such that it will slide upwardly within sleeve 35 when aligned with the axis of chamber 18. However, when cartridge 11 is offset into portion 37, the top rim of the cartridge bears against shoulder 38 and limits upward movement thereof. When cartridge 11 is positioned beneath shoulder 38, the lower nose assembly 20 is extended outwardly through the bottom of body 12 in writing position.

For the purpose of moving cartridge 11 downwardly into the writing position and shifting it laterally beneath shoulder 38, the lower end or foot of plunger 26 is provided with a pair of laterally spaced

teeth

40 and 41 having bottom surfaces inclined upwardly and outwardly in the direction of shoulder 38. The surface of tooth 40 adjacent shoulder 38 bears upon the corresponding rim portion of the tubular shell of cartridge 11, while the surface of tooth 41 bears upon the opposite rim portion of the cartridge.

With cartridge 11 retracted upwardly into the carrying position as shown in Figs. 1 and 2, thumb pressure upon plunger head 27 moves plunger 26 downwardly, driving the cartridge with it by reason of the engagement of

teeth

40 and 41. During this portion of the movement,

teeth

40 and 41 are both engaged with the rim of cartridge 11, but tooth 40 has contact with the inner edge of the rim wall, and exerts a greater lateral force upon the cartridge than does tooth 41 should there be any slight misalignment or wear of the working surfaces.

After the top of cartridge 11 has passed below shoulder 38, the lateral camming action of tooth 40 forces the cartridge to shift laterally away from the axis of chamber 18 and into offset portion 37. However, the maximum lateral throw which can be exerted by tooth 40 is limited by the thickness of the wall of cartridge 11. After tooth 40 has slipped within cartridge 11, as shown in Fig. 3, tooth 41 continues the camming action and moves the cartridge outwardly further into offset portion 37. Thus the cartridge 11 is shifted laterally a sufficient distance to hook firmly beneath shoulder 38, and nose assembly 29 is locked outwardly into the writing position.

To prevent any accidental dislodgement of cartridge it from beneath shoulder 38 due to the pressure exerted on nose assembly 20 in writing, sleeve 34 is formed with a downwardly projecting lip 43 at the inner edge of shoulder 38. As is best seen in Fig. 6, lip 43 is formed with a straight inner edge and an upwardly tapered outer surface. This tapered outer surface of lip 43 permits the cartridge 11 to be dislodged from beneath shoulder 38 by a straight side thrust, but at the same time prevents accidental sliding movement. In order to hold plunger 26 against rotation within sleeve 34 and maintain

teeth

40 and 41 in the proper position relative to shoulder 38, I provide a small pin or key 44 projected inwardly from the inner surface of the sleeve. Key 44 slides in a keyway 45 extended longitudinally along plunger 26, as is best seen in Fig. 7.

I have thus far described the components of the operating mechanism by which the cartridge 11 is moved downwardly from the carrying position to the writing position. It can also be understood that releasing means must be provided for dislodging cartridge 11 from beneath shoulder 38 so that it can again be moved upwardly to the carrying position under the urging of spring 24. To this end I provide a releasing button 46 extended radially through the side wall of cap 13 into offset portion 37 and spaced downwardly below shoulder 38. Preferably, button 46 is spaced peripherally from pocket clip 31 so that the releasing action is entirely independent of the action of the clip.

Button 46 has a head 47 projecting outwardly through cap cover 29, and is slidably mounted for limited movement in the wall of insert 28 with the inner end being adapted to bear against the side of cartridge 11. To limit the movement of button 46, an enlarged collar 48 is constrained for movement between a reduced journal bushing 49 formed at the inner edge of insert 28, and a reduced opening 50 formed in cover 29. For ease of assembly, button 46 is of such length that it may be moved into insert 28 while cover 29 is pressed on, and is thereafter locked in place by the cover. When cartridge 11 is locked downwardly in the writing position as shown in Fig. 4, button 46 is pushed outwardly so that head 47 is raised from the surface of cover 30. By pressing inwardly on head 47, cartridge 11 is pushed laterally out of offset portion 37 and into alignment with the axis of chamber 18. This, of course, releases cartridge 11 from beneath shoulder 38 and lip 43 so that it is free to slide upwardly within sleeve 35 and into the retracted carrying position.

While I have thus shown and described a preferred embodiment of my invention in detail, variations of design and construction will be apparent to those skilled in the art. Therefore, I do not wish to be limited to the preferred embodiment, except as defined in the appended claims.

I claim:

1. A ball point writing instrument comprising: a barrel having an open front end and an inner axially extending chamber formed with an internal side projection at the rear end thereof; a tubular writing cartridge having an ink reservoir and a ball point assembly, said cartridge being loosely mounted in said barrel for sliding movement from an enclosed carrying position to an exposed writing position extended through said open end, the rear end of said cartridge being rockable away from the axis of said barrel; spring means urging said cartridge toward said carrying position; operating means including an op crating plunger mounted at the rear end of said barrel and constrained for axialsliding movement, said plunger having a foot formed with laterally spaced inclined teeth, one of said teeth engaging the rim of said cartridge adjacent said projection to shift said cartridge away from the axis of said barrel and beneath said projection, and the other of said teeth thereafter engaging the opposite side of the rim of said cartridge for continuing the lateral shifting movement to securely position said cartridge under said projection whereby upon the rearward retraction of said plunger said cartridge is held in writing position; and means for releasing said cartridge from beneath said shoulder for retraction to said carrying position.

2. A ball point writing instrument comprising: a barrel having an open front end and an inner axially extending chamber formed with an offset portion at one side thereof terminated rearwardly by an overhanging shoulder; a tubular writing cartridge having an ink reservoir and a ball point assembly, said cartridge being loosely mounted in said barrel for sliding movement from an enclosed carrying position to an exposed writing position extended through said open end, the rear end of said cartridge being movable laterally from the axis of said barrel to a position within said offset portion; spring means urging said cartridge toward said carrying position; operating means including an operating plunger mounted at the rear end of said barrel and constrained for axial sliding movement alongside said shoulder, said plunger having a foot formed with laterally spaced inclinedteeth, one of said teeth engaging the rim of said cartridge adjacent said shoulder to shift said cartridge away from the axis of said barrel and beneath said shoulder upon forward movement of said plunger, and the other of said teeth thereafter engaging the opposite side of the rim of said cartridge for continuing the lateral shifting movement to securely position said cartridge under said shoulder whereby upon the rearward retraction of said plunger said cartridge is held in Writing position; and a releasing button mounted for lateral sliding movement in said barrel, said button having a head projecting outwardly from the side of said barrel and an inner end for engagement with the side of said cartridge to release said cartridge from beneath said shoulder for retraction to said carrying position.

3. A ball point writing instrument comprising: a barrel having an open front end and an inner axially extending chamber formed with an offset portion at one side thereof terminated rearwardly by an overhanging shoulder, said shoulder having a downwardly projecting inner lip; a tubular writing cartridge having an ink reservoir and a ball point assembly, said cartridge being loosely mounted in said barrel for sliding movement from an enclosed carrying position to an exposed writing position extended through said open end, the rear end of said cartridge being movable laterally from the axis of said barrel to a position within said offset portion; spring means urging said cartridge toward said carrying position; operating means including an operating plunger mounted at the rear end of said barrel and constrained for axial sliding movement alongside said shoulder, said plunger having a foot formed with laterally spaced inclined teeth, one of said teeth engaging the rim of said cartridge adjacent said shoulder to shift said cartridge away from the axis of said barrel and beneath said shoulder upon forward movement of said plunger, and the other of said teeth thereafter engaging the opposite side of the rim of said cartridge for continuing the lateral shifting movement to securely position said cartridge rim outside of said shoulder lip whereby upon the rearward retraction of said plunger said cartridge is held in writing position; spring means urging said plunger toward said rearward retracted position; and a releasing button mounted for lateral sliding movement in said barrel, said button having a head projecting outwardly from the side of said barrel and an inner end for engagement with the side of said cartridge to release said cartridge from beneath said shoulder for retraction to said carrying position.

4. A ball point writing instrument comprising: a barrel having an open front end and an inner axially extending chamber formed with an offset portion at one side thereof; a sleeve fitted within the rear end of said barrel and'having an end providing a shoulder overhanging said offset portion, said end having a downwardly projecting lip at the inner edge thereof'formed with a rearwardly inclined outer surface; a tubular writing cartridge having an ink reservoir and a ball point assembly, said cartridge being loosely mounted in said barrel for sliding movement from an enclosed carrying position to an exposed writing position extended through said open end, the rear end of said cartridge being moveable laterally from the axis of said barrel to a position within said offset portion; spring means urging said cartridge toward said carrying position; operating means including an operating plunger mounted for sliding movement within said sleeve, said plunger having a foot formed with laterally spaced inclined teeth, one of said teeth engaging the rim of said cartridge adjacent said shoulder to shift said cartridge away from the axis of said barrel and beneath said shoulder upon forward movement of said plunger, and the other of said teeth thereafter engaging the opposite side of the rim of said cartridge for continuing the lateral shifting movement to securely position said cartridge rim outside of said sleeve lip whereby upon the rearward retraction of said plunger said cartridge is held in writing position; spring means urging said plunger toward said rearward retracted position; and a releasing button mounted for lateral sliding movement in said barrel, said button having a head projecting outwardly from the side of said barrel and an inner end for engagement with the side of said cartridge to release said cartridge from beneath said shoulder for retraction to said carrying position.

5. A ball point writing instrument comprising: a barrel having an open front end and an inner axially extending chamber formed with an offset portion at one side thereof; a sleeve fitted within the rear end of said barrel and having an end providing a shoulder overhanging said offset portion, said end having a downwardly projecting lip at the inner edge thereof formed with a rearwardly inclined outer surface; a tubular Writing cartridge having an ink reservoir and a ball point assembly, said cartridge being loosely mounted in said barrel for sliding movement from an enclosed carrying position to an exposed writing position extended through said open end, the rear end of said cartridge being movable laterally from the axis of said barrel to a position within said offset portion; a coil spring positioned Within the front end of said chamber and engaging said cartridge to urge said cartridge toward said carrying position; operating means including an operating plunger mounted for sliding movement within said sleeve, said plunger having a foot formed with laterally spaced inclined teeth, one of said teeth engaging the rim of said cartridge adjacent said shoulder to shift said cartridge away from the axis of said barrel and beneath said shoulder upon forward movement of said plunger, and the other of said teeth thereafter engaging the opposite side of the rim of said cartridge forcontinuing the lateral shifting movement to securely position said cartridge rim outside of said sleeve lip whereby upon the rearward retraction of said plunger said cartridge is held in writing position; key means mounted on said sleeve and said plunger for holding said plunger against rotation therein; a coil spring mounted rearwardly of said sleeve and surrounding said plunger for urging said plunger toward said rearward retracted position; and a releasing button mounted for lateral sliding movement in said barrel, said button having a head projecting outwardly from the side of said barrel and an inner end for engagement with the side of said cartridge to release said cartridge from beneath said shoulder for retraction to said carrying position.

References Cited in the file of this patent UNITED STATES PATENTS 2,584,569 Frentzel Feb. 5, 1952 2,587,935 Wall-ace Mar. 4, 1952 2,693,170 Sears Nov. 2, 1954 FOREIGN PATENTS 273,976 Switzerland June 1, 1951