US3836265A

US3836265A - Isposable mechanical pencil assembly

Info

Publication number: US3836265A
Application number: US00360070A
Authority: US
Inventors: M Kapilow
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-26
Filing date: 1973-05-14
Publication date: 1974-09-17
Anticipated expiration: 1991-09-17

Abstract

A disposable mechanical pencil includes a tubular barrel having a forward tapered end through which the lead is adapted to project. A tube which receives this lead is disposed interiorly of the barrel and in substantially concentric relation therewith. This tube is generally U-shaped with a forward pinched end for resiliently engaging the lead and preventing it from falling out of the tube. The rear end of the tube includes a laterally projecting arm which engages with inner surfaces of the barrel and cooperates therewith in centering the tube within the barrel. A carrier including a forward end within the tube in engagement with the lead acts to shift the lead forwardly out of the barrel when a laterally projecting handle is manually actuated. The handle is adapted to move through aligned slots in both the barrel and the tube and also serves as an indicator for the amount of lead remaining within the tube. The carrier is provided with a resistance means in the form of a bend, surfaces of which engage the interior of the tube thereby preventing the lead from being pushed back into the tube under normal writing pressure.

Description

[ DISPOSABLE MECHANICAL PENCIL ASSEMBLY [76] Inventor: Marvin Kapilow, 8 Sound Rd, Rye,

The portion of the term of this patent subsequent to Nov. 13, 1990, has been disclaimed.

22 Filed: May14, 1973 21 Appl. No.: 360,070

Related US. Application Data [63] Continuation-in-part of Ser. No. 257,357, May 26,

1972, Pat. NO. 3,771,882.

[ Notice:

[52] US. Cl. 401/80, 401/82 [51] int. C1 B43k 21/06 [58] Field of Search 401/80, 82-84, 401/109] 12 [56] References Cited UNITED STATES PATENTS 1,508,171 9/1924 DOlier 401/80 1,891,682 12/1932 Meyer 401/84 2,029,731 2/1936 Maurer 401/83 2,314,777 3/1943 Farrington 401/84 X 3,070,069 12/1962 Ruden 401/111 3,265,201 8/1966 Edwards 401/84 3,771,882 11/1973 Kapilow 401/80 1*0ept. 17, 19%

427,562 6/1967 Switzerland 40l/l ll [5 7] ABSTRACT A disposable mechanical pencil includes a tubular barrel having a forward tapered end through which the lead is adapted to project. A tube which receives this lead is disposed interiorly of the barrel and in substantially concentric relation therewith. This tube is generally U-shaped with a forward pinched end for resil iently engaging the lead and preventing it from falling out of the tube. The rear end of the tube includes a laterally projecting arm which engages with inner surfaces of the barrel and cooperates therewith in centering the tube within the barrel. A. carrier including a forward end within the tube in engagement with the lead acts to shift the lead forwardly out of the barrel when a laterally projecting handle is manually actuated. The handle is adapted to move through aligned slots in both the barrel and the tube and also serves as an indicator for the amount of lead remaining within the tube. The carrier is provided with a resistance means in the form of a bend, surfaces of which engage the interior of the tube thereby preventing the lead from being pushed back into the tube under normal writing pressure.

16 Claims, 6 Drawing Figures ll DISPOSAIBLIE MECHANICAL PENCIL ASSEMBLY REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 257,357 filed May 26, 1972 now US. Pat. No. 3,771,882 granted Nov. 13, 1973.

SUMMARY OF THE INVENTION A principal object of this invention is to provide a disposable mechanical pencil having the advantages and attributes of the pencil disclosed in the above referenced patent application and further one that is more simple in construction and easier to assemble at reduced costs without sacrificing reliability or efficient operation. Futher objects and advantages will become apparent from the following detailed description which is to be taken in conjunction with the accompanying drawing illustrating somewhat preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawing:

FIG. I is an elevational view of a mechanical pencil assembly in accordance with the present invention;

FIG. 2 is an enlarged fragmentary longitudinal sectional view taken along the line 2-2 of FIG. 1 showing the interior and operating mechanism of the assembly;

FIG. 3 is a fragmentary longitudinal sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along the line 44 of FIG. 3;

FIG. 5 is an enlarged fragmentary sectional view of the forward tip of the pencil barrel and associated forward end of the carrier and lead; and

FIG. 6 is a cross-sectional view taken along the line 6--6 of FIG. 2 showing the relationship between the rear end of the carrier and the interior of the barrel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated mechanical pencil assembly 10 includes an outer barrel or shell 12 having a rear end 14 defined also by raised projection 15 and a tapered forward end 16. The forward end 16 terminates in a reduced opening 18 which is of uniform diameter throughout and cooperates in preventing the lead from wobbling when most of it has already been consumed. The barrel may be fabricated of low cost material and in the successful application of the invention, it has been molded of polystyrene. In this connection the reduced tapered end 16 of the pencil includes three equally spaced recesses 26 formed from the male die of the mold which is provided with corresponding outwardly projecting ribs. These ribs mate with surfaces of the female die to take weight off the tip of the male die. In this manner, damage or breaking of the male die is significantly reduced. Of course the ribs may project from the female die with equally effective results. The barrel I2 is also provided with a longitudinally extending slot 28, the purpose of which will be discussed in detail shortly. This slot 28 extends into aligned recess 29 in the raised projection 15.

A conventional eraser may be disposed in the rear open end 14 of the barrel 12. This eraser is preferably solvent cemented in place. Suitable solvents include methyl-ethyl-ketone, methylene chloride, trichlorethylene and ethylenedichloride. The eraser cooperates in holding the tube 30 in the barrel l2 and as will be evident shortly the eraser 20 and tube 30 serve as a stop for one another and both operate to self-locate each other in relationship to the barrel 112.

The lead 24 is supported interiorly of the barrel l2 by the tube 30 which may be formed of worked sheet metal having the indicated cross-sectional configuration shown in FIG. 4. Towards this end, the tube is U- shaped over a major portion of its length and defines a longitudinally extending slot 32 aligned with slot 28 in the barrel 112. The forward end 34 of the tube 30 is centered as a result of the inter-engagement with the inner surface 36 to properly align the lead 24 in the opening 118. As indicated in the drawing tube end 34 is defined by a bending or working the opposed marginal edges towards one another thereby permitting the tube at this end to grip the opposed surfaces of the lead in a resilient manner as a result of the springiness of the sheet metal. In this manner the lead 24 is frictionally engaged thereby preventing it from unintentionally falling out; and in effect renders the pencil drop-proof in that should the lead break, the pencil remains operational. The back end of the tube 30 is centered interiorly of the barrel 18 as a result of the inter-engagement of the inner surfaces of the barrel and the laterally projecting arm 38. As shown this arm 38 engages with the inner end of the eraser 20 in attaining the self-location of the tube 30 and eraser 20 as discussed in the above.

A carrier 40 is employed to push the lead 24 out through the opening 118 for writing purposes. Towards this end, carrier 40 includes a forward end 42 in engagement with the rear end of the lead 24. The carrier 40 which may be of metal also includes an intermediate bend 44 enabling surface of the carrier to engage with internal surfaces of the tube 30 in providing sufficient frictional resistance to prevent the lead from being pushed back into the tube through the opening 18 under ordinary writing pressure. In the event normal writing pressure is exceeded and to minimize breakage of the lead tip, the frictional resistance is overcome and the lead will retract together with the carrier within the tube 30. The rear end of the carrier 48 includes an arm or handle 46 which projects laterally through the slot 32 of the tube 30 and the slot 28 of the barrel 12. This handle may be grasped or engaged by a finger to urge the carrier 40 forwardly and consequently the lead 24 out through the opening I8. As will be appreciated, the position of the handle 46 is also an indication of the amount of lead present in the tube 30. The forward portion 44 of the carriage is sufficiently long to not only permit substantially complete consumation of the lead but to enable the forward end of slot 28 to move rearwardly so that it will not be in the zone of the barrel 12 that is ordinarily grasped by the fingers when writing. Similarly, the handle 46 will not be in this zone when the lead is all consumed.

The rear of barrel I2 also includes a pocket clip 48 which is most advantageously molded integrally on the barrel 12. It will be noted that clip 48 does not include any undercuts and possesses a configuration predominantly of straight lines. As a result, a cam operated split mold is not necessary for molding and consequently a parting line is not present. In addition, it is found that by controlling the shrinkage of the clip 48, and particularly its thicker base, the clips free end will shift closer to the outer surface of barrel 12.

As explained and illustrated in detail in the above referenced application, the mechanical pencil of this invention also contemplates cooperating structure which permits self-aligning of the assemblied tube 30 and carrier 40 in the barrel 12. In this connection the outer terminal end of handle 46 conveniently rides in the recess 29 and upon further insertion eventually passes into and projects out of the aligned slot 28. Thereafter the eraser 20 is mounted in place to center and locate the tube 30 within the barrel 12 as previously described.

As the lead 24 is consumed, the handle 46 is urged forwardly to expose more lead. The user need only retract carrier 40 and then push lead 24 back into barrel 12 when the pencil is not used or when carried in the pocket. This preserves the lead tip and prevents it from being accidentally broken. Also, the inside of the pocket will not be marked or damaged by the exposed lead tip. When the lead 24 is fully expended the user need only disg'ard the entire assembly because of the relatively low cost and need only acquire another pencil with a full length of lead 24. In this connection there has been found that considerably more writing time is provided by the pencil of this invention when compared with a wooden pencil, because essentially all of the lead is used. Whereas this is not so with the wooden pencil because lead is wasted through repeated sharpenings and when this pencil becomes too short, it is disgarded.

Thus, several aforenoted objects and advantages are most effectively attained, although a single somewhat Y preferred embodiment of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

What is claimed is:

1. A disposable mechanical pencil assembly comprisa tubular barrel having a rear end and a tapered forward end having a reduced opening through which writing lead is adapted to project;

a tube for receiving the lead disposed concentrically within the barrel, the forward end of the tube being centered by the taper of the forward end, and centering means centering the rear end of the tube within the barrel, the forward end of the tube including means of reduced cross-section relative to the remainder of the tube for resiliently gripping the lead for cooperating in retaining the lead in the tube; and a carrier slidably disposed in the tube for forcing the lead forwardly out through the forward opening of the barrel whereby all of the lead in the tube can be consumed and resistance means formed by surfaces of the carrier and internal surfaces of the tube for preventing retraction of the lead under ordinary writing pressure, the carrier including a manually graspable handle projecting outwardly through the barrel and serving as an indicator of the amount of lead in the tube, and both the barrel and the tube being provided with aligned slots through which the handle is adapted to travel. 2. The invention in accordance with claim 1, wherein the rear end of the tube includes a laterally projecting arm for cooperating with the adjacent interior surfaces of the barrel in centering the rear end ofthe tube within the barrel.

3. The invention in accordance with claim 2, wherein an eraser projects outwardly from the rear end of the barrel and engages with the arm to cause self-location of both the eraser and the tube in relation to the barrel.

4. The invention in accordance with claim 3, wherein the eraser is solvent cemented to the interior surfaces of the barrel by a material selected from the group con,- sisting of methylethylketone, methylene chloride, trichlorathylene and ethylenedichloride.

5. The invention in accordance with claim 1, wherein the tube being formed of sheet material bent intermediate its ends into a substantially U-shaped crosssectional configuration with the marginal side edges thereof defining the tube slot.

6. The invention in accordance with claim 5, wherein the marginal side edges of the forward end of the tube are further worked and bent towards one another in defining the means of reduced cross-section.

7. The invention in accordance with claim 1, wherein the reduced opening includes a substantially cylindrical portion of predetermined length for minimizing wobbling of the lead when only a relatively small part thereof is not consumed.

8. The invention in accordance with claim 1, wherein the rear end of the barrel includes an outer projection having an inner recess which is aligned and communicates with the slot of the barrel, said recess cooperating in self aligning the tube and associated carrier when these parts are assembled.

9. The invention in accordance with claim 8, wherein the internal diameter of the barrel plus the depth of the recess approximately equals the distance from the tip of the handle to the distal side of the tube.

10. The invention in accordance with claim 1, wherein the resistance means includes an intermediate bend for frictional engagement with the associated interior faces of the tube.

11. The invention in accordance with claim 1 wherein the barrel is of one-piece integral construction.

12. The invention in accordance with claim 11, wherein the barrel is plastic and a pocket clip is integrally molded as part of the barrel and the clip is defined primarily by straight line construction and the entire barrel with clip is free from any parting line formed by a split mold.

13. The invention in accordance with claim 1, wherein the barrel is plastic and the tube and carrier are metal.

14. The invention in accordance with claim 1, wherein the resistance means when exceeded permits the lead to be retracted in the barrel.

15. The invention in accordance with claim 1, wherein the carrier is of predetermined length so that the forward end of the slot of the barrel and consequently the handle are rearwardly of the zone of the barrel normally grasped by the fingers of the user during writing while permitting substantially a major portion of the lead to be consumed.

16. The invention in accordance with claim 1, wherein the barrel is of molded plastic material and the tapered forward end includes spaced slots caused by a pin of either a male or female mold engaging surfaces of the other mold to prevent breakage of the pin during molding.

Claims

1. A disposable mechanical pencil assembly comprising: a tubular barrel having a rear end and a tapered forward end having a reduced opening through which writing lead is adapted to project; a tube for receiving the lead disposed concentrically within the barrel, the forward end of the tube being centered by the taper of the forward end, and centering means centering the rear end of the tube within the barrel, the forward end of the tube including means of reduced cross-section relative to the remainder of the tube for resiliently gripping the lead for cooperating in retaining the lead in the tube; and a carrier slidably disposed in the tube for forcing the lead forwardly out through the forward opening of the barrel whereby all of the lead in the tube can be consumed and resistance means formed by surfaces of the carrier and internal surfaces of the tube for preventing retraction of the lead under ordinary writing pressure, the carrier including a manually graspable handle projecting outwardly through the barrel and serving as an indicator of the amount of lead in the tube, and both the barrel and the tube being provided with aligned slots through which the handle is adapted to travel.

2. The invention in accordance with claim 1, wherein the rear end of the tube includes a laterally projecting arm for cooperating with the adjacent interior surfaces of the barrel in centering the rear end of the tube within the barrel.

4. The invention in accordance with claim 3, wherein the eraser is solvent cemented to the interior surfaces of the barrel by a material selected from the group consisting of methylethylketone, methylene chloride, trichlorathylene and ethylenedichloride.

5. The invention in accordance with claim 1, wherein the tube being formed of sheet material bent intermediate its ends into a substantially U-shaped cross-sectional configuration with the marginal side edges thereof defining the tube slot.