US3289639A

US3289639A - Retractable writing instrument

Info

Publication number: US3289639A
Application number: US434414A
Authority: US
Inventors: Charles K Lovejoy
Original assignee: Scripto Inc
Current assignee: Scripto Inc
Priority date: 1965-02-23
Filing date: 1965-02-23
Publication date: 1966-12-06
Anticipated expiration: 1983-12-06
Also published as: GB1030568A; SE312282B; NL6512633A; CH439012A; DE1269540B; ES316802A1; BE672732A

Description

Dec. 6, 1966 c. K. LOVEJOY RETRACTABLE WRITING INSTRUMENT 4 Sheets-Sheet 1 Filed Feb. 23, 1965 .1 L K 8 mm r a h C NM @N QW WW MNQ ATTORNEY Dec. 6, 1966 c. K. LOVEJOY RETRACTABLE WRITING INSTRUMENT 4 Sheets-Sheet 53 Filed Feb. 23. 1965 Charles K. Lovejy A TTOR N F Y Dec. 6, 1966 c. K. LOVEJOY 3,289,639

RETRACTABLE WRIT ING INSTRUMENT Filed Feb. 23, 1965 4 Sheets-Sheet 5 INVENTOR Charles K. Love 0y ATTORNEY Dec. 6, 1966 c. K. LOVEJOY 3,239,539

RETRACTABLE WRITING INSTRUMENT Filed Feb. 25, 1965 4 Sheets-Sheet 4 I NV ENTOR Charles K. Lovejoy w /jfia 11 1 ATTOR N EY United States Patent 3,289,639 RETRACTAFLE WRITING INSTRUMENT Charles IQ. Lovejoy, Atlanta, (2a., assignor to Scripto, Inc., a corporation of Georgia Filed Feb. 23, 1965, Ser. No. 434,414 2 (Ilaims. (Cl. 120-4203) The present invention relates to writing instruments and more particularly to one in which the writing element may be moved alernately between projected and retracted positions.

The essence of this invention deals with the mechanism that accomplishes the movement of the writing element between projected and retracted positions and with releasable latching at each position. The operation of the mechanism of the present invention is accomplished by successive depressions of a plunger member that extends from the rear of the writing instrument. The mechanism consists of two moving parts, the plunger and the latch member which cooperate with the interior configuration of the rear barrel portion of the writing instrument.

T he present mechanism is an outgrowth of the mechanisms that are disclosed and claimed in the following US. patents: US. Patent No. 2,930,354 to Lockwood, U.S. Patent No. 2,930,355 to Bollerup, US Patent No. 2,930,356 to Liguori and US. Patent No. 3,062,191 to Van Haltern et a1. All of the above enumerated patents, as well as the present application, are assigned to a common assignee. Each of these prior art mechanims, as well as that of the present invention, is characterized by a rocking latch that is adapted to move longitudinally within the barrel of the writing instrument and rock transversely in a longitudinally plane. Each latch member is a floating member confined Within the rear barrel portion of the writing instrument.

The mechanism of the present application differs from the previous rocking latch mechanisms in that the shoulder portion of the latch extends as opposed projections in a plane that is substantially perpendicular to the plane in which the latch rocks. Furthermore, the barrel latch shoulders that the latch member engages are positioned outwardly of and adjacent to the plane in which the latch member rocks. In addition, a given shoulder portion of the latch member engages a barrel latch shoulder at both the projected and retracted positions.

One of the main advantages'of the mechanism of the present invention is that when it is engaged at either of its alternate positions, its restraining lugs are in contact with two oppositely arranged forwardly facing barrel latch shoulders that lie substantially in the same transverse plane. Therefore, the rearwardly directed shear load exerted by the return spring of the writing element and the rearwardly directed force developed when the writing element is in contact with a Writing surface are distributed over two areas, thereby allowing the use of a softer, hence more economical plastic, such as butyrate, for molding the rear barrel portion of the writing instrument.

Secondly, the mechanism of the present invention is adapted for automatic assembly due to the fact that the plunger and latch can be hopper-fed since the plunger is a solid of revolution and the interior configuration of the rear barrel portion orients the latch for proper leadin and snap-in retention.

It can be readily seen that a Writing instrument embodying the present invention requires a minimum of parts that are of simple construction. Furthermore, economy of assembly is realized due to the fact that the mechanism of the present invention, as well as the other cooperating parts of the Writing instrument are adaptable for automatic assembly.

These and other features and advantages of my invention will be apparent from the following description of a presently preferred embodiment thereof taken in conjunction with the attached drawings wherein:

FIG. 1 is a longitudinal cross-sectional view of a writing instrument embodying the propel/repel mechanism of the present invention;

FIG. 2 is an enlarged partial longitudinal cross-section of the upper portion of the writing instrument showing the propel/repel mechanism positioned with the writing unit in retracted position;

FIG. 3 is an enlarged partial longitudinal cross-section of the upper portion of the writing instrument showing the propel/repel mechanism with its latch member shifted to a position for engaging the forward facing barrel latch shoulders;

FIG. 4 is an enlarged partial longitudinal cross-section of the upper portion of the writing instrument showing the propel/repel mechanism with its latch member engaged with the forward facing barrel lat-ch shoulders to position the writing unit at its projected position;

FIG. 5 is an enlarged partial longitudinal cross-section of the upper portion of the writing instrument showing the propel/repel mechanism with its latch member being disengaged from the forward facing barrel latch shoulders to allow retraction of the writing instrument;

FIG. 6 is an enlarged front elevational view of the latch of the present invention;

FIG. 7 is an enlarged side elevational view of the latch of the present invention;

FIG. 8 is an enlarged top plan view of the latch of the present invention;

FIG. 9 is a cross-sectional view taken along the line 99 in FIG. 6;

FIG. 10 is an enlarged elevational view of the plunger of the present invention;

FIG. 11 is a cross-sectional view taken along the line 11-11 of FIG. 10;

FIG. 12 is an enlarged longitudinal cross-sectional view of the upper barrel portion with the latch and plunger components of the mechanism removed;

FIG. 13 is a transverse cross-section taken along the line 13-13 of FIG. 12;

FIG. 14 is a transverse cross-section taken along the line 14-14 of FIG. 12;

FIG. 15 is a transverse cross-section taken along the line 15-15 of FIG. 12; and

FIG. 16 is an enlarged partial cross-section taken along the line 1616 of FIG. 12.

Referring to FIG. 1, my improved writing instrument 10 includes a forward barrel portion 12 having a main central bore 13 formed therein, and a writing tip aperture 14 of reduced diameter at its forward end. Within the central bore 13 there is formed a rearwardly facing spring seating shoulder 16. A writing unit 18 is slidably disposed within the main central bore 13 and has formed at its forward end a forwardly facing spring seating shoulder 20. Disposed between the rearwardly facing barrel shoulder 16 and the forwardly facing shoulder 20 which is formed on the writing unit 18, there is positioned a spring 22 which normally urges the writing instrument .10 rearward toward retracted position. At the rear of the forward barrel portion 12, external screw threads 24 are formed on the outer surface thereof. A rear barrel portion 26 is removably fitted to the forward barrel portion 12 by threaded engagement, the external threads 24 of the forward barrel portion 12 engaging internal, interrupted screw threads 28 that are formed in the forward interior portion of rear barrel portion .26. The interrupted portions of the internal screw threads 28 provide latch lead-in tracks 29, the function of which will be described later in detail. On the exterior portion of the rear barrel 31 portion 26 there is attached a clip 30 which is clinched in position in the customary manner.

Referring to FIG. 12, the internal configuration of the rear barrel portion 26 is clearly illustrated. It is seen that a plurality of longitudinally extending lead-in spears 32 are arranged at equally spaced intervals within the interior of rear barrel portion 26, each being positioned rearwardly of and aligned with a threaded section of the interrupted screw threads 28. While FIG. 12 shows only one half of the rear barrel portion 26 which contains two lead-in spears, the mating section is a mirror-like image which likewise contains two lead-in spears, bringing the total to four equally spaced spears 32. It should be noted that the lower lead-in spear 3-2 is elongated at 34, and its adjacent spear in the mating section (no-t shown) is likewise elongated. The purpose of this is to facilitate assembly which will be described later. Arranged between each pair of adjacent lead-in spears 32 are latch orientation and retention ridges 35. Each of these ridges 35 slopes rearwardly toward one of the latch guide channels 40.

Referring to FIG. 16, the configuration of the latch retaining ridge 35 is shown as having a forwardly facing surface 36 that is substantially perpendicular to the interior wall of the rear barrel portion 26, and a rearwardly facing surface 37 that is inclined to the interior surface of the rear barrel portion 26.

Referring to FIG. 14, it will be seen that there are four latch guide channels 40 disposed within the interior of the rear barrel portion 26, each of which terminates in a forward facing shoulder 41. Each pair of oppositely disposed guide channels 41) is arranged in a plane which is perpendicular to the other, both planes being offset from the longitudinal axis of the barrel. At the forward por tion of each guide channel 40 there is formed a forwardly facing barrel latch shoulder 42 which is adjacent said channel and disposed on the opposite side of the longitudinal axis of said writing instrument. Along each leadin spear 32 there is formed a longitudinally extending, inwardly projecting rib 43 that begins rearwardly of the latch retention ridge 35 and forwardly of the barrel latch shoulder 42, and the rib 43 extends rearwardly to a position that is past the most rearward position that the latch will occupy in its retracted position. The function of these inwardly projecting ribs 43 is to prevent rotation of the latch member about the longitudinal axis thereof.

It should be noted in FIG. 12 that the outer edge 42' of each forward facing latch shoulder 42 is rearward of the inner edge 42" of said latch shoulder 42. This affords an outwardly extending, rearwardly slanted surface for the barrel latch shoulder 42 that greatly facilitates maintaining engagement between the latch member 60 and the barrel latch shoulder 42. Also, in the preferred embodiment one of the two opposed latch shoulders that constitute mating sections is disposed a slight distance forward of the other which is positioned opposite thereof. By this minor variation (not shown) one of the latch shoulders is made the master shoulder while the other is the slave shoulder, thereby facilitating movement of the latch into and from engagement with said latch shoulders. The interior of the rear barrel portion 26 is further formed with a forwardly facing, angled plunger retention shoulder 44 that is disposed forwardly of the plunger aperture 46.

Referring now to FIGS. 6 through 11, structural details of the latch and plunger members are shown. FIGS. and 11 show the plunger member construction generally denoted by the numeral 50 as having an external operating tip portion 52 and an intermediate portion 53 of enlarged diameter. At the juncture of the external tip portion 52 and the intermediate plunger portion 53 there is a rearwardly slanting shoulder 54 for abutting the plunger retention shoulder 44 to define the plungers most rearward position. At the forward portion of the plunger 50 there is an enlarged stabilizing ring portion 55, the forll ward portion of which includes a forwardly facing contact area 56. In the forward portion of the plunger 50 there is formed a comically-shaped forwardly facing latch rocking relief recess 58. A metallic plunger cup 59 may be fitted on the operating tip portion 52 for decorative effect.

Referring now to FIGS. 6 through 9, it will be seen that the lat-ch member 60 of the present invention is of a [generally saddle-like configuration having a main body portion 61, the rear portion of which is provided with a rearwardly facing, transverse contact area 62. This contact area is in the form of a strip that extends across the smaller breadth dimension of the latch. Outwa'rdly of, and on opposite sides of, the rearwardly facing transverse contact area strip are disposed forwardly extending leg portions 64 having, at the outer side of each leg 64, transversely extending restraining lugs 66. It should be noted that the rearward surfaces of these restraining lugs 66 are angled upwardly and outwardly for cooperation with the angled barrel latch shoulders 42. The forward portion of the main body portion 61 of latch 60 is formed with an axial portion 68 that is in rockable engagement with the rear of the writing unit 18. Each of the corners of the latch 60 is notched at 70 to receive therein barrel ribs 43 for cooperative functioning to prevent rotation of the latch 60 within the rear barrel portion 26.

To further insure that the restraining lugs 66 will remain in engagement with the barrel latch shoulders 41 and 42 the clearance that exists between the writing element 18 and each forwardly extending leg 64 is less than the linear distance of engagement between each lug 66 and the barrel latch shoulders 41 and 42. This provides a construction that makes it impossible for accident-a1 unlatching due to inward movement of the legs due to axial stresses.

The present mechanism may be manually assembled by dropping the plunger cup 59 and the plunger 50 into the rear barrel portion 26, then inserting the latch into the rear barrel portion so that lugs 66 travel in guide tracks 29 and between lead-in spears 32, into contact with latch retention ridge 35 where the lugs ride rearwardly along the face 36 until they abut a lead-in spear 32, whereupon the lugs 66 are snapped over ridge 35 for retaining the latch within the rear barrel portion 26. The forwardly extending legs 64 are sufficiently elastic to allow for sufficient inward movement for the lugs 66 to move over the ridge 35.

For automatic assembly the components of the pen are assembled at successive stations mounted around the periphery of a dial (or wheel) which indexes periodically. Two pre-assembly operations are performed prior to assembly at the dial, i.e., attaching the clip to the cap and placing the spring on the refill cartridge. All parts at the dial are fed automatically from hoppers to the various stations with the exception of the cap/clip sub-assernbly which is loaded small-end-down into a receiving nest by an operator at the initial or loading Station #1.

Subsequent operations are as follows:

Station #2: Drop two parts into the cap at this station, the plunger cup first and then the plunger.

Station #3: Probe for presence of plunger.

Station #4: Position latch over the cap and push it into place with an air-operated plunger designed to assure proper orientation.

Station #5: Probe for presence of latch.

Station #6: Deposit a band over the large end of the cap.

Station #7: Insert cartridge and spring into the cap (spring end up).

Station #8: Drop a barrel over the refill (pointed end up).

Station #9: Screw the barrel into the cap.

Station #10: Eject finished pen downward through th nest.

Operation In peration, the latch member 60 is disposed to float freely within the rear barrel portion 26 and to follow a particular operating motion therein by reason of the interaction of actuating forces imposed thereon by depression of the related plunger member 50 in opposition to the rearward biasing force applied through the writing unit 13 by the spring 22, and in relation to the rocking and latching arrangement of the latch member 60 with respect to the rear barrel portion 26 as is described in detail below.

Assuming that operation starts with the latch member 60 in retracted position as indicated in FIG. 2, the oppositely disposed, transversely extending latch lugs 66 are engaged with the oppositely disposed forwardly facing stop shoulders 41 formed at the rear of latch guide channels 49; and, the rearward fopce applied through the writing unit 18 has caused two notched corners 70 of the latch 60 to bear against the ribs 43 and the inner wall of the rear barrel portion 26.

Upon the subsequent depression of the plunger member 50 for shifting the writing unit 18 to the projected position, as shown in FIG. 3, operating contact of the plunger member 50 with the latch member 60 is such as to cause a first forwardly facing plunger contact area 56 to engage the outer edge of the rearwardly facing latch contact area 62 that is on the side of the latch that is abutting the inner wall of the rear barrel portion 26 and thereby induce a clockwise couple on the latch 60 to cause the lugs 66 to swing under, and into engagement with, the forwardly facing barrel latch shoulders 42 when the forward extremity of latch guide channels 40 are cleared. The projected position is shown in FIG. 4 with the force of spring 22 acting through the writing element 18 to urge the opposite two notched corners 76 of latch 60 to bear against opposite ribs 43 and the opposite inner wall of rear barrel portion 26. It can be seen that the conically-shaped recess 58 of the plunger 50 affords the necessary clearance between the plunger 50 and the latch 60 to allow rocking of the latch in its movement into and out of engagement with the barrel latch shoulders 42.

Return of the writing element 18 is accomplished in a similar manner. Referring to FIGS. 4 and 5, it will be seen that, when the plunger 50 is again depressed, a second forwardly facing plunger contact area 56 contacts the opposite outer edge of the rearwardly facing latch contact area 62 that is now abutting the opposite inner wall of rear barrel portion 26 and the opposing forces exerted through the plunger 50 and the writing element 18 create a counter-clockwise couple that causes the latch lugs 66 to swing out of engagement with the barrel latch shoulders 42 and into position for rearward movement in guide channels 40 toward the retracted position shown in FIG. 2.

It can be readily seen that the latch member of the present unit is adapted both to move longitudinally within the barrel and to rock transversely therein, being fulcrumed for rocking on the rear of the writing element 18, and being further fulcrurned at its forward and rearward position about forwardly facing barrel latch shoulders 41 and 42 through the engagement therewith of latch lugs 66. The latch member 66 in fact accomplishes dual latching at both projected and retracted positions due to its having two lugs 66 that engage two pairs of

shoulders

41 and 42.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise, except as defined in the appended claims.

What is claimed as invention is:

l. In a writing unit comprising a barrel having a forward end and a rearward end, a depressi'ble plunger located at said rearward end for movement within said barrel, a writing element biased rearwardly within said barrel and slidably disposed therein to shift longitudinally between projected and retracted positions with respect to said forward end, and a laterally rockable and longitudinal movable latch member disposed Within said barrel rearwardly of said writing unit and forwardly of said plunger, said latch member having a rearwardly facing contact area and a longitudinally spaced shoulder portion, said barrel having a shoulder positioned therein for re leasably engaging said shoulder portion of said latch and pivoting said latch thereabout to position said writing element at projected position, said plunger having a forwardly facing cont-act area disposed in opposing operative relation to said latch member contact area and being engageable with said latch member upon successive plunger depressions for laterally rocking said latch member alternately in opposite directions for engaging and disengaging said latch shoulder portion with said barrel shoulder portion; the improvement comprising said latch having its shoulder portion formed as two laterally extending projections each being disposed on opposite sides of said latch in a plane that is substantially perpendicular to the plane in which said latch rocks.

2. In a writing instrument, the improvement of claim 1, characterized further in that said barrel shoulder consists of two oppositely disposed transversely spaced forwardly facing portions that lie in a plane that is substantially perpendicular to the plane in which the latch member rocks.

References Cited by the Examiner UNITED STATES PATENTS 2,930,355 3/1960 Bolleru-p -42.03

FOREIGN PATENTS 1,075,981 2/1960 Germany.

LAWRENCE CHARLES, Primary Examiner.

Claims

1. IN A WRITING UNIT COMPRISING A BARREL HAVING A FORWARD END AND A REARWARD END, A DEPRESSIBLE PLUNGER LOCATED AT SAID REARWARD END FOR MOVEMENT WITHIN SAID BARREL, A WRITING ELEMENT BIASED REARWARDLY WITHIN SAID BARREL AND SLIDABLY DISPOSED THEREIN TO SHIFT LONGITUDINALLY BETWEEN PROJECTED AND RETRACTED POSITIONS WITH RESPECT TO SAID FORWARD END, AND A LATERALLY ROCKABLE AND LONGITUDINAL MOVABLE LATCH MEMBER DISPOSED WITHIN SAID BARREL REARWARDLY OF SAID WRITING UNIT AND FORWARDLY OF SAID PLUNGER, SAID LATCH MEMBER HAVING A REARWARDLY FACING CONTACT AREA AND A LONGITUDINALLY SPACED SHOULDER PORTION, SAID BARREL HAVING A SHOULDER POSITION THEREIN FOR RELEASABLY ENGAGING SAID SHOULDER PORTION OF SAID LATCH AND PIVOTING SAID LATCH THEREABOUT TO POSITION SAID WRITING ELEMENT AT PROJECTED POSITION, SAID PLUNGER HAVING A FORWARDLY FACING CONTACT AREA DISPOSED IN OPPOSING OPERATIVE RELATION TO SAID LATCH MEMBER CONTACT AREA AND BEING ENGAGEABLE WITH SAID LATCH MEMBER UPON SUCCESSIVE PLUNGER DEPRESSIONS FOR LATERALLY ROCKING SAID LATCH MEMBER ALTERNATELY IN OPPOSITE DIRECTIONS FOR ENGAGING AND DISENGAGING SAID LATCH SHOULDER PORTION WITH SAID BARREL SHOULDER PORTION; THE IMPROVEMENT COMPRISING SAID LATCH HAVING ITS SHOULDER PORTION FORMED AS TWO LATERALLY EXTENDING PROJECTIONS EACH BEING DISPOSED ON OPPOSITE SIDES OF SAID LATCH IN A PLANE THAT IS SUBSTANTIALLY PERPENDICULAR TO THE PLANE IN WHICH SAID LATCH ROCKS.