US2868170A - Retractable mechanism of pinch yoke type - Google Patents

Description

1959 w. B. SPATZ 2,868,170

RETRACTABLE MECHANISM OF PINCH YOKE TYPE Filed Oct. 14, 1953 2 Sheets-Sheet 1 29 u PVILTEQ B. SPA 3 RETRACTABLE MECHANISM OF PINCH YOKE TYPE Walter B. Spatz, Los Angeles, Calif, assignor, by mesne assignments, to Paper Mate Manufacturing Company, Culver City, Calif a corporation of Delaware Application October 14, 1953, Serial No. 385,973 2 Claims. (Cl. 120-42113) This invention relates to writing instruments especially of the ball point pen type and more particularly relates to an improved mechanism for extending and retracting the writing element of such instruments.

It is now quite feasible to construct a ball point writing instrument with a writing element movable from an extended writing position to a retracted carrying position. Such an instrument is not generally subject to leakage,

avoids the use of an inconvenient separate cap, and may be conveniently carried with its writing element retracted and instantly readied for use.

The prior art discloses a rather large number of mechanisms directed toward providing suitable extending and retracting mechanisms for ball point writing instruments, but in general such mechanisms are subject to a number of persistent disadvantages which are inherent or characteristic of all such types of mechanisms. Thus, in general it is necessary to provide an operating mechanism which involves a rather complex device to he compacted into a relatively small confined space. Such a device must necessarily include rather tiny and intricate parts. In most prior types of retracting mechanisms these parts have been numerous, delicately related and attached to each other, expensive to manufacture, and very difiicult to assemble. As a natural and expected consequence the parts may wear out, or become distorted or misaligned, to cause the mechanism to jam, become difficult to operate, or even break down completely. Accordingly, a suitable retracting mechanism involving a minimum number of direct acting elements economical to manufacture, capable of being easily assembled into a device which is easy to operate, positive and dependable in operation and sufficiently rugged to withstand the hard use of a large number of operations without failure, is much to be desired.

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

It is another object of the invention to provide an improved retracting mechanism for writing instruments which is easy to operate, conveniently used, positive and dependable in operation, and sufficiently rugged to withstand the hard use of a large number of operations without failure.

It is another object of the invention to provide an operating mechanism for Writing instruments having a positive and direct acting means for urging a writing element into an extendedwriting position.

It is a further object of the invention to provide an operating mechanism for writing instruments having a simple direct acting and positive locking means for holding a writing element in an extended position.

It is a still further object of the invention to provide an operating mechanism having a minimum number of sirn-' ple relatively rugged working parts permitting of easy and rapid assembly and capable of withstanding hard use.

It is a further object of the invention to provide a re tracting mechanism for writing instruments operable by ICC means of a carrying clip at the upper end of the writing instrument.

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

Fig. 1 is an elevational view partly in section of my retractable writing instrument.

Fig. 2 is an enlarged longitudinal sectional view of the upper case showing the operating clip released and the writing element in its normal retracted position.

Fig. 3 is a transverse section through IIIIIII of Fig.

Fig.4 is a transverse section through IV-IV of Fig. 2.

Fig. 5 is a transverse section through VV of Fig. 2.

Fig. 6 is a transverse section through VI-VI of Fig. 2.

Fig. 7 is a sectional View of the upper case, similar to .Fig. 2, showing the operating clip depressed and the writing element in full extended position.

Fig. 8 is a sectional view of the upper case, similar to Fig. 2, showing the operating clip released and the Writing element extended in normal writing position.

Fig. 9 is a sectional view of the upper case similar to Fig. 2, showing the operating clip depressed and the writing element retracted.

In general, the invention contemplates the provision of a mechanism for extending and retracting the writing element in ballpoint pen type writing instruments, to be used in conjunction with awriting instrument wherein the writing element is movable axially into retracted and projected positions, and wherein spring means normally biasing the writing element into retracted position are provided. The mechanism of 'the invention includes a sleeve carried by the upper end of the writing element provided with a lug extending laterally and annularly around its wall, a push rod which is movable longitudinally and laterally with respect to the sleeve, a pinch yoke resiliently biased into a sleeve grasping position, suitable upwardly pinch yoke grasps it. The writing element is retracted.

when the push rod is again urged longitudinally downward and cams on the camming surface of the upper case into engagement with the sleeve grasping portion of the pinch yoke releases its grasp and allows the writing unit to retract under its normal bias.

Referring now to the drawings the reference numeral 10 generally designates a writing instrument. which is one embodiment of the invention. 10 includes a writing element 11 having an upper inkcarrying cartridge 12, and a lower ink dispensing tube- .13. The tube 13 is provided at its extreme lower end 14, with a socket to retain a ball point 115. The cartridge 12 may be encased in a sleeve 16, having a lip portion 17. to limit its downward motion on the cartridge 12, and a lug portion 18, for a purpose to be more particularly explained.

The writing element 11 is preferably slidably supported in housing consisting of a lower case portion 19 with a downwardly directed port 20, through which the extreme lower end 14 of the writing element 11 may be projected, and an upper case portion 21 which may include a slotted outer shell 22, and an inner body member 23. The lower case 19 and the upper case 21 are preferably adapted to be screw threaded together so 1 that they may be disengaged to permit replacement of V the writing element 11.

The writing instrument a The writing element '11 is biased upwardly into retracted position by a retracting spring 24 positioned between the case 19 and the elementll.

The body member 23 is preferably a substantially cylindrical molded member which may be press fittedinto the outer shell 22 to form the upper case portion 21. The member 23 may be, provided with an axial bore 25 having upwardly and downwardly directed openings 26 and 27 respectively. At the upper end of the member 23 the opening 26 may be considerably widened.

Within the widened upper portion of the axial bore 25, a downwardly directed shoulder 28 may be formed to contact the upper end of the writing element 11 and arrest its upwardly biased movement. For a purpose to be moreparticularly illustrated an offset channel or groove 29 may be provided adjacent and communicat ing with the axial bore 25 and two radial slots or wells 30, 31 maybe provided in the outer wall of the member 23.

Operating means may comprise a normally upwardly biased member movable axially of the case and extend ing from the upper case portion 21. Such means may comprise a plunger 32 provided with an upstanding pin 33, the pin extending upwardly through opening 34 formed in the upper end of the upper shell 22. Although a clip may be attached to the case 21 in any suitable manner, the drawings illustrate an embodiment wherein the clip 35 is attached to the pin 33, as by threads or a press fit, and is movable therewith. The plunger 32 is provided with a conical lower end loosely fitting into axial bore 25 of body member 23 and is connected to a push rod or operating arm 36 extending downwardly adjacent the writing unit 11.

The operating arm of push rod 36 may be provided with a ported portion 37 encircling the pin 33 and downwardly extending rectilinear portions 38 and 39 connected by a curved or inclined camming portion 40. The lower end of the push rod 36 may be provided with a spatulate portion 41 having a concave face facing the writing element. The push rod extends through the offset channel slot or groove 29 formed in body member 23 adjacent and communicating with the axial bore 25. The opposite end 42 of the push rod 36 is bent downwardly as shown and is preferably wider than slot 43 in the upper case, thereby closing said slot. Upward bias is imparted to the operating means by a return spring 44 surrounding the lower end of the plunger 32 and bearing against the upper end face of the body member 23 and the ported portion 37 of the push rod 36.

Means are provided for holding the writing implement 11 in projected writing position. Such means comprise a pinch yoke in the form of a substantially planar annular member 45 provided with a blade portion 46, the end of the blade being firmly attached to the body member 23 as by means of the anchor 47. The entire pinch yoke is made from resilient material, the annular portion being bent to occupy a plane at less than 90 to the axis of the writing cartridge and the blade or tongue. The annular portion includes non-parallel spaced faces providing an aperture slightly larger than the diameter of the cartridge or writing unit or of the sleeve 16 carried thereby, the spaced faces receiving therebetween the writing unit and normally grasping the unit. In the event the ink reservoir of the writing unit is of metal, the sleeve 16 need not be employed, since the lug 18 may be formed integral with the cartridge; since the pinch yoke in its operative position actually grasps cartridge 12 and some cartridges are made of resinous or plastic materials which are readily indented and deformed, the metallic sleeve 16 is preferably used in order to prevent deformation or impairment of the cartridge.

Means are provided to guide and control lateral motion to push rod 36 so as to permit the spatulate end 41 to contact lug 18 upon depression of the pin 33 (when the writing unit is retracted) and thereby move the writing unit into projecting position, and upon a second depression of the pin 33 to cause the end of the push rod 36 to contact the pinch yoke and release its grip upon the writing unit, thereby allowing biasing spring 24 to retract the writing unit. Such means may comprise a guide surface, camming wall, or inclined camming shoulder 48 formed in the outer wall of groove 29 of body portion 23, such camming shoulder cooperating with camming portion 40 of the push rod 36. It will be noted that rectilinear portion 38 of the push rod is yieldably urged laterally against the wall of groove 29 by reason of the resilient pressure of end 42 against the inner wall surfaces of case 21 adjacent slot 43, but as long as camming portion 40 is in contact with the outer wall of groove 29 above shoulder 48 the spatulate end 41 will engage lug 18 of the writing unit.

Operation of the retractable writing instrument is as follows: when the writing instrument is in a carrying or retracted condition, its parts are positioned as shown in Fig. 2. The writing element 11 is fully retracted under the influence of the retracting spring 24. Pin 33, plunger 32 and clip 35 are in up position and the push rod 36 is against the wall of the body member 23, with its spatula-shaped end 41 near to engagement with the lug 18.

When pin 33 or plunger 32 is depressed, push rod 36 moves longitudinally and compresses the return spring 44. Simultaneously, as it moves longitudinally, the push rod 36 engages lug 18 and moves the writing element into fully extended position as shown in Fig. 7.

As soon as plunger 32 or clip 35 is released, the spring 44 is able to extend and return the plunger 32 and the push rod 36 to the positions shown in Fig. 8. However, the writing element is held in projected writing position through the pinching action of the annular member 45 on the sleeve 16. Moreover, due to the inclination of the annular member 45 with respect to the sleeve 16, its pinching action becomes more pronounced with any retracting tendency of the writing element. The positions of the parts when the writing element is fully extended are shown in Fig. 8.

Upon the next depression of the clip 35, the push rod 36 again is caused to move longitudinally, but this time the camming portion 40 of the push rod 36 slides over the camming shoulder 48 of the body member 23 and guides the spatula-shaped end 41 laterally outwardly beyond lug 18 and into aligned engagement with lip 49 of annular member 45 as shown in Fig. 9. By this action, the annular member 45 is sprung open and caused to release its grip on the sleeve 16, and under the influence of the retracting spring 24, the writing element 11 retracts.

When the operating clip is released the plunger 32 and the push rod 36 are returned to their normal fully retracted positions shown in Fig. 2.

It will be noted that the usual type of clip includes a number of small parts and a leaf spring which yieldingly presses the clip toward the outer surface of the shell or case of the writing implement. In the embodiment illustrated, the clip 35 may be a simple solid one-piece element, some lateral yield being imparted to the lower or free end of the clip by the resiliency of the operating arm 36 and end 42 as they bear against the groove and inner surface of the shell.

Having fully described my invention, it is to be under stood that I do not wish to be limitedto the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. In a writing instrument including an upper case portion provided with an upper body portion therein, said upper body portion having an axial bore adaptable to slidably receive the upper end portion of a writing unit, and a longitudinal groove adjacent said bore: a writing unit carrying a lug, said writing unit extending into the 5 axial bore; an axially movable, upwardly biased actuating member extending from the upper end of the case portion; an actuating arm attached to said actuating member and extending downwardly through said groove, said actuating arm being resiliently biased laterally away from the writing unit and lug thereon; means on the upper body portion for positioning said actuating arm proximate to said writing unit when said arm is in retracted position for alignment and engagement of said arm with 7 said lug at a predetermined portion of its travel in said groove to move the writing unit longitudinally with it for projection of the unit; and a longitudinally extending resilient blade provided with a virtually transversely extending pinch yoke at one end, the other end of said blade being fixed in the upper case portion, said pinch yoke grasping said writing unit to resist upward movement of the writing unit therethrough, said writing unit being upwardly biased into retracted position and said pinch yoke extending laterally of the axis of the writing unit a greater distance than said lug and disposed below said lug, said positioning means at another portion of travel of said arm permitting said arm to move laterally outwardly for passing over and beyond said lug for engagement of the actuating arm with the pinch yoke to release the grasp of the pinch yoke upon the writing unit to permit upward travel of the unit into retracted position.

2. In a writing instrument including an upper case portion provided with an upper body portion therein, said upper body portion having an axial bore adaptable to slidably receive the upper end portion of a writing unit, and a longitudinal groove adjacent said bore: an upward-; ly biased writing unit extending into the axial bore and provided with a lug; an upwardly biased actuating member extending from the upper end of the case portion and axially movable with respect thereto; an actuating arm attached to the actuating member and extending downwardly through said groove alongside said writing unit, said actuating arm being resiliently biased laterally away from the writing unit and lug thereon; means on 6 the upper body portion for positioning said "actuating arm proximate to the writing unit when the arm is in retracted position for alignment and engagement of said arm with said lug at a predetermined portion of its travel in said groove to move the writing unit longitudinally with it for projection of the unit; and a resilient blade extending longitudinally along said writing unit and provided with a transversely extending pinch yoke at one end, the other end of the blade being fixed in the upper case portion, said pinch yoke having an inclined position relative to the axis of the writing unit to grasp the writing unit to resist upward movement of the writing unit therethrough, said positioning means on the upper body portion at another portion of travel of said "arm cooperating with said arm to guide said arm int-o engagement with said pinch yoke for moving said yoke out of said inclined position to release said writing unit for movement thereof into retracted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,726,011 Ziegler Aug. 27, 1929 2,500,439 Tursky Mar. 14, 1950 2,505,267 Weber Apr. 25, 1950 2,514,610 Schweitzer July 11, 1950 2,526,268 Perraud Oct. 17, 1950 2,584,569 Frentzel Feb. 5, 1952 2,692,580 Kahn et al. Oct. 26, 1954 2,715,888 Liguori Aug. 23, 1955 FOREIGN PATENTS 53,926 Germany Oct. 10, 1890 2,838 Great Britain of 1896 934,235 France Jan. 10, 1948 608,084 Great Britain Sept, 9, 1948 964,025 France Ian. 18, 1950 809,514 Germany July 30, 1951 814,568 Germany Mar. 11, 1952

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