US3424535A - Self-feeding pencil - Google Patents

Description

Jan. 28, 1969 K. F. sc`H|scHKow 3,424,535.

SELF FEEDING PENC IL Sheet of:

Filed Oct. 18, 1966 Jan' 28 1969 K. F. scHlscHKow 3,424,535

` SELFFEEDING PENCIL Filed Oct. 18, 1966 Sheet Of 2 United States Patent O Claims ABSTRACT 0F THE DISCLOSURE A self-feeding writing instrument is disclosed in which the elongated marking members are received within the central bore of a clutch guide freely carried within a casing. Lateral clutch plates receive the marking members within the guide and restrict the movement 0f the marking members to the feed direction through the instrument. A clutch jaw responsive to pressure upon the point of t-he writing instrument slides within the clutch plates and `along the marking member therein. Release of the pressure upon the instrument tip permits the clutch guide, plates and jaw to fall toward the Writing tip carrying the manking member into writing position.

This invention relates to self-feeding pencils and more particularly to a pencil which will advance a supply of lead therethrough as required without adjustment by the user.

In my Patent No. 2,866,438, issued Dec. 30, 1958, there is disclosed a self-feeding pencil in which the lead is advanced an amount necessary for writing when required without any action on the part of the user other than the normal writing movements. The lead is initially loaded through the tip of the pencil case and is held therein by a spring-like chuck. However, only one length of lead can be carried within the pencil at a time and writing has to be interrupted when each length of lead is used up. If the pencil is shaken sharply lalong its vertical axis, t-he lead will often feed out of the pencil an undesirable amount. This uncontrolled self-feeding action often results in wasted lead.

Accordingly, it is an object of the present invention to provide a self-feeding pencil which will be free of the shortcomings of prior art devices.

Another object of the present invention is to provide a self-feeding pencil which will accept a large number of leads and continue to advance them through the pencil until they have all been used without the need for loading at the end of each lead.

A further object of the present invention is to provide la self-feeding pencil which will require no attention with respect to its readiness for writing for extremely long intervals of time.

An object of the present invention is to provide a durable trouble-free simplified self-feeding pencil.

Still another object of the present invention is to provide a self-feeding pencil which will not advance the lead except when writing requires it.

A feature of the present invention is its clutch and friction clutch assembly for advancing the lead through the pencil.

Another feature of the present invention is its axial lead path from the magazine to the writing tip.

A further feature of the present invention is its means for gripping the lead as it is fed out of the pencil to prevent breakage.

Still another feature of the present invention is its large lead capacity.

The invention consists of the construction, combination and arangement of parts, as herein illustrated, described and claimed.

Patented Jan. 28, 1969 In the accompanying drawings, forming a part hereof there is illustrated one form of embodiment of the invention, in which drawings similar reference characters designate corresponding parts, and in which:

FIGURE 1 is a View in vertical section of a complete embodiment of the present invention on an enlarged scale.

FIGURE 2 is a fragmentary view partly in vertical section of the writing tip of the pencil taken on line 2-2 of FIGURE l, looking in the direction of the arrows.

FIGURES 3, 4 and 5 are cross-sectional views ta-ken on lines 3 3, 4 4, and 5-5, respectively of FIGURE 2, looking in the direction of the arrows.

FIGURE k6 is a fragmentary View of the writing tip in the lead advancing position with certain parts shown in vertical section and others in dashed lines for the sake of clarity.

FIGURE 7 is a view similar to FIGURE 2 showing the second step in advancing lead through the pencil.

FIGURE 8 is a view similar to FIGURE 7 showing the result of successive steps in advancing lead through the pencil.

FIGURE 9 is a somewhat exploded view of the combined clutch and friction clutch shown in FIGURES l, 2, 7 and 8.

FIGURE l() is a somewhat isometric View of the clutch .guide member shown in FIGURES l, 2, 6 and 7.

FIGURE 11 is a cross-sectional View taken on line 11-11 in FIGURE 6.

The present invention provides a self-feeding pencil in which a quantity of elongated leads are caused to slip one by one from a magazine into an axially slideable clutch mechanism. The clutch mechanism is responsive to the pressure exerted upon the writing tip of the pencil which is forced into the pencil casing, when no lead is projecting from the tip. As the tip moves inwardly it causes the clutch mechanism to slide up along the lead coming from the magazine. When the tip is lifted from the writing surface, the lead and the clutch mechanism which grasps the lead and moves downwardly of the pencil casing. Successive tip movements will bring the lead into writing position thereby pre-venting the tip from being pushed into the casing and causing further lead feed. When the exposed lead is worn down, additional lead will be fed out by the nor-mal action of raising and lowering the pencil tip during writing.

Referring to the drawings and particularly to FIG- URE l, 10 indicates a pencil casing havin-g an upper cap portion 11 and a hollow lower portion 12. Male and female threads 13, 14 -join the two casing portions. When the upper casing portion 1.1 is unscrewed from the lower casing portion 12 there is exposed a magazine chamber 18 to receive a quantity of pencil leads 17. An elongated sleeve 20 is secured, as by press fitting, within the lower casing portion 12. The upper end of lthe sleeve 20 has a funnel shaped plug 21. The plug 21 is provided with a central opening 22 large enough for a single lead 17 to slide therethrough but too small for more than one lead at a time. The tapered upper surface 23 of the plug 21 will always guide a single lead into the opening 22 as the preceding lead is fed through the pencil in the hereinafter more fully described manner. The plug 21 thus forms the bottom of the magazine chamber 1,8.

The lower end of the sleeve 20` is thickened as indicated at 24 to receive a clutch guide member 25, best shown in FIGURE 10. rIhe guide member 25 has a tubular body portion 26, the Walls of which have opposed longitudinal slots 27 and opposed lateral windows 28. A an-ged portion 29 at the top of the guide overlies the thickened portion 24 of the sleeve 20 and moves freely within the sleeve 20.

A clutch assembly 30, best shown in FIGURE 9, is received within the bore 3.1 of the guide 25 and is provided with spaced plate members 32, and a lead receiving jaw 33. The plate members 32 have a substantially semi-cylindrical body portion 34 with a tapered portion 3S interconnecting a thickened body portion 34A with the upper body portion. A lug 36 extends outwardly from the t-hickened portion of each plate and serves to guide `and `maintain the orientation of the clutch as it slides iwithin the guide member 25. The lu-gs 36 are received within the slots 27 of the guide 25.

yEach plate is formed with a tlat inner face 37 into which there is cut an axial groove 38. The -groove 38 is arcuate in cross-section and Imay be provided with knurled or roughened lead engaging surfaces 39. The top of each plate 32 is machined to form a portion of a cone as indicated at 40 so that the lead 17 is guided into the jaw 3.3 as it passes through the plug 21.

The jaw 33 has a washer-like base 41 and two spaced leaf members 42 -extending upwardly therefrom. The jaw 33 is preferably made of steel or bronze havin-g springlike properties and the leaves 42 slightly sprung so as to be further apart at the base 41 than at the top. An axial passage 43 is provided through the jaw 33 extending between the leaves 42 and through the base 41. The passage 43 is of a size which will just penmit the lead 17 to slide therethrough with slight frictional contact. Each leaf 42 is beveled -at its top as shown at 44 to lead the leads 17 into the passage 43.

When the clutch 30 is assembled the plates 32 are disposed on each side of the leaves 42 `and a small coil spring 45, best shown in FIGU-RES 6, 7 and 8, placed between the plates 32 and the base 41 of the jaw 33. The upper portion of the coil spring 45 is fitted loosely around the bottom 34B of the plates 32, and bears against enlarged portion 34A. The lower portion of the coil spring 45 rests upon the base 41 and is positioned by a small stepped portion 46 thereon.

A plurality of small spherical members such as steel balls 47, best shown in FIGURES l and 4, completes the clutch assembly. The balls 47 are slipped into the lateral windows 28 of the guide member 25 and bear against the tapered portion 35 of the plates 33. The balls 47 are retained in place, when the pencil is assembled, by the sleeve 20, as best shown in FIGURE l.

The bottom of the lower casing 12 is tapered as indicated at 48 and its internal bore 49 formed ywith a series of steps to conform to the pencil elements. The rst step 50 from the writing end of the pencil serves as a seat for a flange 5.1 on the writing tip 52. The tip 52 is freely received within the bore 49. The second step 53 is adjacent the base 41 of the clutch.

The flange 51 acts as a stop for the downward movement of the base. The third step 54 lies beneath the guide 2S within the casing 12. The fourth step 55a acts as a stop to position the sleeve 20 ywithin the casing 12. The steps 50 and 55a serve to facilitate the asembly of the pencil by insuring the proper relationship between the parts as they are placed within the casing.

With the pencil assembled as shown in FIGURE l, the operation of the pencil will become clear from an examination of FIGURES 6, 7 and S.

Starting with the condition where leads 17 have been placed in the chamber 18 but there is no lead in the writing tip 52, as shown in FIGURE 2, the writing tip is pushed inwardly of the casing tip 48, as the pencil is brought into contact with the writing surface 56 (see FIGURE 6). As the tip 52 moves into the casing the anged portion 51 of the tip slides the clutch jaw 33 `and the guide 25 upwardly. The coil spring raises the clutch plates 32 which are quickly engaged by the steel balls 47 bearing on the tapered portion 35 to stop the upward travel of the plates. If there is no lead in the jaw 33, the writing tip 52 `moves further into the housing 12, the clutch jaw -33 continues to move upwardly together with the guide 25 until the assembly assumes the condition shown in FIGURE 6, where the balls enter the space 25A above the thickened portion 24 of the slee-ve 20. At this juncture the upward travel of the clutch jaw will have been stopped by the bottom of the casing 12 bearing against the surface 56. The clutch assembly 30, and the leaves 42 are raised .and the clutch plates 32 slightly parted to permit the lead 17 to slide therebetween, and into the bevel 44 of the jaws 33. As the tip 52 is raised from the writing surface 56 it drops, the coil spring 45 is released and returns to its original position thereby allowing t-he clutch assembly 30 to drop to its original position. This cycle is hereinafter called .a fast-feed cycle and occurs when there is no lead between the jaws.

As soon as the lead 17 slips between the beveled surface 44, the roughened surfaces 39 of the plates 32 bear against the lead as the clutch assembly 30 drops into the position shown in FIGURE 7. The balls 47 press the plates 32 against the lead 17 as they fall into position between the sleeve 20 and the tapered portion 35 -of the plates 32.

The feed mechanism then enters what is hereinafter termed normal-feed to advance the lead through the friction clutch jaws 33. Normal feed action begins with the movement of the writing tip 52 into the casing 12 in response to pressure of the pencil upon the writing surface 56. The coil spring 45 is raised lby the flange 41 and in turn raises the clutch plates 32. However, a small upward motion of the plates 32 causes the steel balls 47 to force the plates 32 against the lead 17 and lock the plates 32 in position against upward travel by bearing against both the tapered portion and the inner surface of the fixed sleeve 20.

With the plates 32 and lead 17 locked in place, continued pressure on the writing tip 52 will raise the clutch jaw 33, sliding it between the plates 32 and along the lead 17 until an additional amount of lead enters the jaw 33. The spring will compress to permit this action.

At the end of the upward travel of the tip 52 the pencil is raised from the writing surface 56, whereupon the clutch jaw 33, lead 17 and plates 32, drop to the position as shown in FIGURE 1. It will be apparent that successive raising and lowering of the writing tip 52 will advance the lead 17 through the pencil and out of the bore in the tip 52 to the position shown in FIGURE 8, where it extends suiciently lbeyond the tip 52 for writing purposes.

Once the lead 17 has been fed beyond the tip 52, pressure on the lead as in writing will cause it to lift the plates 32. The steel balls 47 will then bear against the tapered portion locking the plates and lead and permit writing without additional lead feed.

If the lead 17 should wear down or break at the tip 52 so that no lead projects, the tip 52 will slip into the casing 12 to repeat the normal feeding operation. When one length of lead is completely used a succeeding length of lead 17 will have slipped into the clutch jaw 33 from the chamber 18 in the manner described above.

By reason of the large bearing surface of the groove 38 the leads can be held within the pencil during writing without crushing or breaking. The steel balls permit the leads to slip downwardly through the clutch assembly 30 and also apply an even `positive pressure to the clutch plates when they are moved upwardly.

It will be apparent from the foregoing that there has been provided a self-feeding pencil capable of accepting a large number of leads and feeding them successively and continuously through the pencil as writing conditions require. While the description has been confined to the use of lead (graphite) and the device characterized as a pencil it is to be understood that any elongated writing material such as crayon, compacted ink or the like may be substituted without departing from the spirit of the invention.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is:

1. A self-feeding writing device comprising a hollow casing, a tapered writing end on said casing, a chamber to receive elongated marking members, means to lead the marking members individually toward the writing end of the casing, an axially bored cylindrical clutch guide freely carried within the casing, lateral windows in the clutch guide in communication with the axial bore, a plurality of small spherical members carried by the windows and extending partially into the axial bore and partially into the clutch guide bore, a clutch assembly slidable within the clutch guide to receive marking members from the chamber, opposed clutch plates in said clutch assembly disposed adjacent the spherical members, an axially bored writing tip slidably carried in the tapered writing end of the' casing axially movable in said end and extending therefrom, means responsive to axial :movement of the writing tip to activate the clutch assembly, and spring means carried by the clutch assembly to move the clutch plates axially upward in the clutch guide in response to axial movement of the writing tip whereby the clutch assembly will successively grasp and advance the individual marking members through the writing device and out of the writing tip bore.

2. A device according to claim 1 in which the clutch guide is provided with opposed longitudinal slots, the clutch plates are formed with outwardly extending lugs slida-bly received within the slots, and a sleeve is xedly carried within the casing between the spherical members and the casing.

3. A device according to claim 1 in which the clutch assembly includes a clutch jaw comprising a washer-like base, opstanding opposed leaf members on said base and an axial bore to receive the marking members therethrough.

4. A device according to claim 1 in which the clutch plates are provided with a thickened portion connected to the 'body of the plates by a tapered surface, said tapered surface being disposed so as to bear against the spherical members when the plates are urged upwardly in the direction of the marking member chamber.

5. A device according to claim 3 in which the spring means is disposed between the base of the clutch jaw and the clutch plates.

6. A device according to claim 3 in which the clutch plates are substantially hemi-spheric in crossesection, have a substantially flat bearing face disposed against the leaf member and an axial groove in said bearing face for frictional contact with the elongated marking members.

7. A device according to claim 3 in which the opposed leaf members are formed of spring-like material and are slightly sprung apart further at their fixed ends than for the remainder of their length.

8. A device according to claim 1 in which the clutch plates are provided with a thickened portion connected to the body of the plates by a tapered surface, said tapered surface being disposed so as to bear against the spherical members when the plates are urged upwardly in the direction of the marking member chamber and the writing tip is in abutting relationship with the bottom of the clutch assembly.

9. A device according to claim 6 in which the surface of the axial groove of each plate is roughened to increase frictional contact with the marking members.

10. A device according to claim 2 in which the clutch guide and clutch assembly are formed with a funnel-like configuration whereby individual marking members are lead from the chamber into the clutch assembly, and the sleeve is thickened for a portion of its length adjacent the guide windows whereby raising the guide will permit the spherical members to move into the space between the sleeve and the guide to further release pressure on the clutch plates and permit lead to fall therebetween.

References Cited UNITED STATES PATENTS 1,430,204 9/ 1922 Waring 401-53 2,353,177 7/1944 Moore 401-65 1,663,742 3/1928 Wilson 401-66 1,745,658 2/1930 Becker 401-53 2,646,775 7/ 1953 Vierling 401-103 X 2,865,330 12/1958 Swank 401-53 LAWRENCE CHARLES, Primary Examiner.

U.S. Cl. X.R. 401-57

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