US2287894A - Mechanical pencil - Google Patents

Description

June 30 1942. '.1. P. LYNN MECHANICAL PENCIL Original Filed June 15',r 1938 lli. A

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Patented June 30, 1942 UNITED STATE s PATENT OFFICE MECHANICAL PENCIL John l. Lynn, Chicago, Ill., assgnor to Dur-- Lite Pencil Company, Melrose Park, Ill., a corporation of Delaware Continuation -of application Serial No. 213354 June 15, 1938. This application October 10,

1941, Serial No. 414,398

cil construction of the type which feeds or` (ci. 12o-11) propels the lead by a step-by-step movement, as 1 by a pumping action exerted on a movable member carried in the upper end of the pencil.

It is an object of this invention to provide a novel pencil of the type referred to, in which the movable pumping or actuating member mounted in the upper end of the pencil is removable therefrom and is capable of being inserted into operative position withv either of its ends innermost, whereby the actuating member referred to is adapted to constitute not only the pumping -member for actuating the lead feeding mechanism, but is also adapted to form an auxiliary part of the pencil, such as, for instance, an eraser thereof, or an eraser magazine or .lead magazine as may be desired in any particular case.

In the pencil of this invention, however, the pumping or actuating member may be entirely removed from the pencil, in which event the lead feeding mechanism will not be accessible for operation while the pumping or actuating member itself is made readily available to present an eraser or a magazine, as may be the case, foruse by or accessibility to the operator. Furthermore, the pumping or actuating `member is' adapted to be inserted into .an upper chamber in the pencil arid in the inserted position to coact by abutment or similar engagement with the associated part of the pencil` mechanism, whereby the pumping movement of the actuating' member will be Ventirely imparted to the lead feeding mechanism for the advancement of leads in a manner characteristic of this type of feeding mechanism.

It is also contemplated that the pumping or actuating member may be inserted with either end innermost, or, in other words, it is intended that the actuating member be reversible, end

. for end, and in either position be adapted to have coacting engagement with the associated pencil mechanism whereby it functions in the pumping or'lead advancing action with equal facility in. either position. When the actuating member is formed as an eraser,'the reversibility permits one end thereof to be provided with a decorative cap for the pencil and the other end to hold an eraser, with the result thatl either the eraser or the decorative cap may be positioned outermost-as may be desired by the operator.

opposite direction.

The fun nature of this invention win be betlized in the construction shown in Figure l, and

here illustrated as eraser assembly.

Figure 3 is an elevational view, partly in cross section, of the pencil shown in Figure 1,- illustrating the same construction but with the pumping or actuating member inserted in reverse position. v

Figure 4 is a cross sectional view taken on the line 4--4 of Figure 2.

Figure 5 is a cross sectional view taken on the line 5-5 of Figure 1.

Figure 6 is a side elevational view of a threaded stem and head-piece utilized in an eraser assembly which constitutes the actuating member i1- lustrated in Figure 2; and

Figure 7 is a side'elevational View of an eraser and' cap member utilized in the assembly constituting the actuating member shown in Figure 2.

By referring to the drawing, and particularly Figure 1 thereof, it will be noted that the form of the invention illustrated comprises a pencil having a body 20 composed of a metallic tube 2| and a finishing sleeve or tube 22, which preferably may be formed of a decorative material such as pyroxylin, molded resin, or any other material suitable for this purpose.

'I'he lower end of the tube 2| tapers inwardly, as shown in Figure l, and terminates in a cylindrical end portionv 23 of reduced diameter, and the outer finishing tube tapers likewise. Fixed within the reduced portion 23 of the metallic tube 2| is a guide block member 24, preferably provided with a shoulder 25 disposed in abutment with the inner tapered surface of the tube 2| so as to hold the guide block against movement 'a propelling and repelling in the direction of the tip of the pencil but permits the guide block` to be withdrawn in the The guide block further has a shoulder-21 adjacent itsupper end to provide a seat for the coil spring 28 disposed thereabove. The lower end of the block projects beyond the end of the .tube 2| andis preferably threaded to form an attachment for the pencil tip 29. The tip is recessed in the manner shown and is preferably provided with slots 30 at its lower end 3i to provide a pair of fingers to press inwardly in a manner to frictionally grip the lead forthe purpose well understood in connection with this type lofipencil.

The Yguide block 24 is provided with a recess 32 and afguide bearing 33 adjacent its top. Disposed within the guide bearing 33 is ancelongated clutch member 34 which is substantially cylindrical in cro'ss section and extends from a point well above the guide block down through the bearing 33 to a point below the end of the guide block and into the upper recess of the tip 29. This clutch is slotted as at 36, adjacent its lower end to form a plurality of fingers which are normally sprung outwardly and which are provided with gripping teeth 31 on their inner surfaces. The clutch ngers are further constructed with outer surfaces which assume a tapered or inclined position when the fingers are sprung outwardly to their normal positions. The

magazine for spare leads and also as a part of the actuating mechanism for pumping the lead during the lead feeding operation.

The upper end of the tube 50 extends upwardly to a point adjacent the upper end of the pencil,

but terminates within the body of the pencil, or,

, in other words, below the upper edge of the pencil body. The upper' end ofthe lead magazine tube 50 is shown at 52 in Figure 1, and is of such construction that it forms an abutment for engagement with a cooperating abutment 50 or BI of the pumping or actuatingmember 62.

clutch member is hollow, as illustrated in Figure 1, end has an internal bore of asize to accom-` modate a writing lead 40 which is caused to feed and pass therethrough during the operation of the pencil.

On the outer surface of the elongated clutch is a small ange 4I, or other suitable abutment, which is adapted lto engage the upper shoulder 42 on the inner surface of the guide block 24 so as to prevent further upward movement of the clutch member when no lead' is disposed between the clutch fingers.

Mounted within the recess provided in the guide block 24 and thetip 29 is afloating sleeve v#I3 which has an internal diameter at its upper portion of suflicient size to `freely pass over the flange 4I, and is of such length that it is permitted to have a limited movement within the recess in which it is located. The sleeve 43 is so constructed that its internal diameter is smaller than the diameter of the bottom of the leadgripping clutch when the ngers thereof are in expanded'position, so that when the clutch member is forced into the sleeve 43, the lowr end of the sleeve will engage the outer tapered surfaces of the clutch fingers and cause the fingers to be moved inwardly in a manner to firmly grip the lead disposed therebetween.

The upper end of the clutch member is threaded, as at 45, and is attached to a lead guide block 46. This block is provided with a shoul- As particularly shown in Figure 1, the actuating member here illustrated is an eraser assembly which is inserted in the upper end of the I pencil, that is, in a manner to occupy the space above the upper end 52 of the lead magazine tube 5U, and in such manner that its lower end 60 engages the upper end 52 of the magazine tube, so that the eraser assembly serves as a means extending outwardly beyond the end ofthe pencil for receiving the manual pumping action and to, in turn. impart the same to the lead magazine tube and thence to the guide block 46 and clutch member 34.

In the form here illustrated, the lower end of the lead magazine is provided with a circular bead 55 which may be rolled into the metallic tube 50 or otherwise formed therein and which provides an annular support or seat for engaging the stored leads 'a short distance above the lower ends thereof. The actionof this support is best illustrated in Figure 1, wherein a new piece of lead 56 is shown in the magazine awaiting subsequent use after the lead 40 has been advanced to a point where its upper end passes below the funnel portion 49 ofthe lead guide block 46. The circular bead 55 prevents the leads 56 from becoming positioned flatly against the sides of the lead magazine and, by virtue of its location near the bottom of the magazine, causes der Hand a hub 48, the latter of which forms l a seat for the upper end of the coil spring 28. The guide block 46 is further provided with a threaded recess providing an attachment for the upper end ofthe clutch members34. The

upper surface of the lead guide block is prefer-y ably provided with a tapered recess 49 which forms a base for a lead magazine of funnel-like shape, which, in cooperation with the means hereinafter described, will assure an accurate feeding of the lead `pieces in succession, one after the other, into the upper endof the clutch tube. It will be noted that the clutch member 34, which is centrally bored to receive the lead, presents its" upper end at the base of the funnel-like `memberywhereby an unobstructed passage is provided for automatically feeding by gravity the leads into the upper end of the clutch member. The --leadguiding block'46 has attached to its outer surfaceametallic-tube 50, which is connected thereto by any suitable means, such as by punch marks 5l. This tube is slidably positioned within the body tube 2| and serves as a ing movement. This structure eliminates the necessityfor excessive shaking or other haphazard attempts to feed the leads.

With this understanding of the above construction, it will be apparent that when the'lead 40, projecting from the lower end ofthe pencil,

-becomes sufciently short to require feeding, the

' upper end of the eraser or actuating mechanism y of the spring 28. .The downward movement of.

62:may be pumped downwardly, preferably by the thumb of the operator, and then permitted to return to its normal position under the influence the actuating or eraser mechanism 52, carried in the top portion of the (pencil, is imparted to the upper end of the magazine tube by the contact between shoulders and 52, with the re'- sult that, the lead guide block 46 is also moved downwardly against the action of the spring 23 and carries with it the clutch member 34, which, by virtue of the constricting action of the sleeve 43, is in tight holding engagement with the lead disposed between the clutch fingers.

Further, as the clutch member moves down wardly, the sleeve 43 is -caused to move down-- wardly also, due to its tight frictional engagement with the tapered portions of the clutch fingers. A s shown in Figure 1, there is an adequate space-in the recesses of the tip 29' to accommodate the clutch and the sleeve 43 in their lowermost positions, but it is to be observed that after the parts have been moved downwardly a predetermined distance the lower end of the sleeve 43 will engage the shoulder B3 provided in the recess of the tip 29, with the result that downward movement of the sleeve 43 is arrested. However, the space in the tip is nevertheless adequate to permit a further downward movement of the clutch member 34, whereby the continued downward thrust causes the clutch member to free itself from the lower end of the sleeve 43 and to move down into position where the spring ngers of the clutch member are free to expand` under the influence of their nonnal resilience:

and to thereby release their grip on the lead.

It will be observed that the downward movement thus effected has caused the lead to move downward bodily with the clutch member against the friction at the outer end of the tip. This movement of the lead is so adjusted that ,its degree of advancement is just sumcient to lengthen the lead the desired amount to renew the available leads for writing purposes.

Upon the release of the actuating member 62,

the magazine tube, lead guide block, clutch and l sleeve are all caused to return to their upper positions by the action of the spring 28, so that upon such release the pencil parts are promptly restored to their lnormal positions. In such normal position, it will be apparent that the sleeve 43 rides upwardly in advance of the tapered -portions of the clutch ngers and continues such upward movement until its upper end abuts the shoulder 42 of the block member 24, which abut- -ment causes the sleeve to come to rest and the clutch ngers to bewedged into the sleeve in a manner to cause the clutch fingers to grip upon the lead atI a new portion thereof.

The clutch mechanism is now in tight engagement with the lead and is, therefore, ready for the next successive downward thrust of the actuating member when the lead is to be advanced. During the return movement, when the clutch is out of engagement with the lead, the

lead is tightly held by the friction gripping ngers at the tip end of the pencil. During the use of the pencil for writing purposes, the lead is not only held by friction at the endl of the -pencil, but is also held against inward movement by the holding action of the clutch itself. It will be apparent that as the particular lead is advanced a number of times through a succession of step-by-step movements, that its end will ultimately become disposed below the-funnel portion 49 of the lead guide block, after which a new lead, held in the magazine in a position tilted toward the lead feeding opening, will automatically feed itself by gravity into the lead-receiving opening, with the result that all of the leads 1 stored in the magazine will'automatically be fed successively, one after the other, until the lead magazine is exhausted.

This type of pencil is capable of holding a relatively large number of leads, and as they are fed successively and entirely automatically the -supply of lead lasts an extremely long time'.

The actuating member may be of any suitable' construction, but as above pointed out, it is in. tended that it be freely removable from the cated above the upper end of the lead magazine and, being removable and reversible, it may be constructed in the form of an eraser which, in turn, may be of usual construction or some special construction, such as that illustrated here.

The illustrated form comprises an eraser which is best illustrated in Figures 2, 4, 6 and 7,'from which it will be noted that the assembly comprises a threaded screw 10 which is permanently attached to a head 1|. drilled and inserted over the screw memberwith the screw end enlarged, as at 12, in the opening 'portions 11 which-fit within the groove 13 of the head, whereby the sleeve is held against axi'al displacement, while at the same time being free to rotate on the head.

Preferably, a cap member18 having a domed or other decorative end 19 is tted over the knurled ange 14 and rlxedly attached thereto. The depending portion 80 of the cap 18 is of such diameter that it forms a continuaton of the cylindrical surface of the tubular body portion 15,

^ from which it will be apparent that the eraser assembly may be inserted into the upper chamber of the pencil with either end innermost. It

will further be apparent that the eraser assembly which constitutes the pencil actuating member may be entirely withdrawn from the pencil by an endwise pull thereof, and when it is so removed the tube 15 may be held in the fingers of one hand while the cap 80 is turned by the other hand, and that such operation will produce a relative turning movement between the tubular body 15 and the screw 10.

Disposed within the tubular body 15 is an l elongated eraser 8| having a central opening 82 chamber in the upper portion'of the pencil lo- 'I5 therein. This eraser has one end fitted in a cap 83 which has acentral screw threaded opening 84 at the top for threaded engagementswith the screw 10. The 'cap further has spring fingers 85 for tightly gripping the eraser, whereby the eraser is held against axial and rotational movement relative to the 'cap member. Furthermore, the spring fingers 85, by virtue of their construction, are caused to project slightly outwardslight frictional drag on the interior of the cylindrical body 15.

The construction described is such that although the 'eraser is not positively held against rotation in the body tube 15, vit will, nevertheless, resist such rotationdue to the frictional action of the spring fingers 85, whereby the turning of the cap 18 with reference to the body 15 will cause the eraser to be projected from the tubular body or drawn into the tubular body, depending upon the relative direction of rotation. Furthermore, when the eraser is turned vinto the tube to the maximum extent possible, the parts will not strike or bind in such manner as might strip the threads of the screw, but, instead, the eraser will turn bodily in the holding tube and thus avoid all damage to the device. y

The opening 82 in the eraser is at all times The head is preferablyl sufii'ciently free lto accommodate the screw without interference. Preferably the openingB! in the eraser does not extend all the way through, l

but this is immaterial because the eraser functions in a satisfactory manner irrespective of whether it is or is not provided with a central hole.

It will thus be apparent thatwhen the eraser i wears down it may be Withdrawn from the end of the pencil and the cap thereof may be turned relative'to the body to cause it to project from the body a suiiicient amount to enable it to be readily used again. If desired, the eraser may be retracted into the body of the tube or. it may be left in its adjusted position.

From the above description it willr be noted that the eraser assembly or other actuating member is capable of being reversed in position so that the cap member IB is inside .of the pencil and the end of-the eraser projects beyond the end of the pencil. When in this iposition, the

ing thrust in exactly the same manner as -when the eraser assembly is in reverse position.

What is claimed is: v

A mechanical pencil having, in combination, lead feeding means at the lower portion thereof and an upper chamber, a lead magazine slidably i mounted in said chamber and having its upper position in said chamber by frictional engageend of the eraser is presented in a manner to be used in the customary way, but at the same time the eraser assembly is stillapable of functioning as the actuating member for the lead feeding mechanism. In suchposition, the outer edge 6I of the cap 80 abuts the upper end 52 of the V,lead magazine tube so as to transmit the operatment with the inside walls of said chamber, and being removable from said chamber by an end- Wise pull but being reversible in saidchamber end to .end for actuating said pencill in either position thereof, and said actuating. means iurtherA having a spacevtherein adapted to house an eraser. JOHN P. LYNN.

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