US1969085A - Automatic lead pencil - Google Patents

Description

Aug. 7, 1934.

A. LEISTENSCHNEIDER ET AL AUTOMATIC LEAD FENG IL Filed Dec. 14, 1932 2 Sheets-Sheet 1 enters w M all 1 1 Aug- 7, 1934 A. LEls'rENscHNlDr-:R r-:r AL 1,969,085

AUTOMATIC LEAD PENCIL Filed DBC. 14, 1932 K 2 Sheets-Sheet 2 F. ...WM

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Patented Aug. 7, 1934 i UNITED STATES AUTOMATIC LEAD PENCIL August Leistenschneider and Konrad Kressel, Dusseldorf, Germany; said Kressel assigner to said Leistenschneider Application December 14, 1932, Serial No. 647,152 In Germany December 19, 1931 15 claims. (cl. 12o-17) v The invention relates to an automatic lead pencil in which the lead is heldwithin the nose of the pencil by a grasping device, which is actuated by a clamping ring, and joined with an inner tube operable by the cap of the pencil. `The existing automatic lead pencils of this sort are very uncertain in operation, as the spring clamping devices weaken quickly and then fail to function properly or else fail to release the lead and draw it back again. The rigid or jointed grasping devices connected to the pushing tube often cause the lead to break. Furthermore the loose grasping rings stick to the clamping device easily, so that the lead when once moved forward is drawn back again when the cap is released. Usually the inner parts cannot be cleaned at all, or only in a very complicated way which cannot be done by the ordinary person. Taken together these disadvantages cause most automatic pencils to fail and become useless'after brief use.

, The above mentioned disadvantages are avoided in the invention by having the grasping device free to move laterally relative to the pushing member. This aords the advantage that the device can adjust itself freely and automatically to the position of the lead determined by the remainder of the mechanism, whereby breakage of the lead is avoided. v A further improvement is attained by a grasping device consisting of two or more loose parts, freely movable relative to one another and to the pushing member, and which can likewise take -hold of the lead readily. Since, on the one hand, a certain grasping pressure is necessary to hold the lead,- and on the other hand too high apres- 4sure on a small surface of the lead would result in pinching off the latter, the grasping members are so constructed as to clamp the lead with relatively large cylindrical surfaces. The loose grasping members are kept suitably independent and free to move at one end, in a recess or other part of the pushing member, whereby extensions over-lapping the pushing member insure that the individual grasping members are always in the correct position for the entry of the leads. A short distance beyond the above described grasping or pushing device an additional spring grasping means for the lead can be arranged to grip the lead especially during the return motion of the pushing member, in order to prevent the leads from being drawn back and thereby to guarantee a positive grasp of the pushing member, especially at the breaks in the row of leads.

The grasping ring *is controlled by a special spring which `returns it to its normal position after the grasping device has been released. whereby premature clamping of the grasping device is positively prevented. The latter has a tubular extension in the direction of the pencil point, the diameter of which is Isuitably smaller than that of the ring, and whichcontrols the action of the grasping members'at its end. The advantage is thereby obtained, of being able to locate .the grasping member near the point of the pencil. vThe end consists of Itwo parts, a springy, stepped inner part and an. outer rigid nosepiece as a retainer for the inner looselyplaced part, so that the elasticity cannot be overstrained and cannot weaken. Furthermore, the outer nose surrounds the inner part in such a Way that Athe inner part is held in a central position. In addition, lthe grasping device is thereby held in the proper position in the nose, whereby lead breakage is positively prevented. The stepped, springy end-piece is provided with a recess, in which -the loose parts of the open grasping device are-free to move. By unscrewing the outer nosepiece, the entire mechanism for feeding the leadl can be taken apart and thus cleaned easily. Finally, special stops are provided, which prevent the empty grasping device from being drawn too far into the grasping ring, on the one hand, and prevent the grasping members from jamming in the nosepiece, on the other. 85

To -these and other ends the invention resides in certain improvements andcombinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Figs. 1-3 show an embodiment of the invention in an automatic pencil, drawn in longitudinal section on a large scale, with various posi-.- tions of the movable parts.

Fig. 4 shows a detail greatly enlarged, While Figs. 5-8 show other arrangements of grasping devices.

In the barrel 1 of the pencil, which may be made of any desired material, a tube 2 is xed into which a sliding sleeve 3 is introduced to receive the reserve leads.- The upper rim 4, made springy by slotting the sleeve 3, catches in the grooves 5, 6 of the cap 7, with which the latter engages successively when put on over the springy nm.

The cap 7 could also be attached by screwing it on or in any other suitable marmer. The sleeve 3 is connected to a hollow guide 8, to which the inner tube 9 is fastened. The parts 9, 3

. the lower rim of the tube 2 and? are pressed upward by a helical spring 10, which is located between the guide 8 and a sleeve 11 surrounding the inner tube 9. From the sides of the sleeve 11 tongues 12 are sprung inward, projecting through slots 13 in the inner tube 9 and rest with their ends against the lead 14 in the tube 9. The sleeve 11 rests on another sleeve 15 which catches by a projection 16 under the top with an inner shoulder Vwall 17. This serves, in case there is no lead in the pencil, as upper stop for a sleeve 18, sliding within the sleeve l5 and xed to the lower end of the inner tube 9; in the sleeve 18 4is held the grasping device for the lead 14, consisting of several, in the example three, longitudinal members 19, 20. The parts 19, are perfectly loose and independent ofveach other and engage in a recess 22 of the sleeve 18 with their upper, ringshaped ends 21, so that they are free to move laterally. Small projectionsr 23 of the parts 21 rest on a projecting rim 24 on the end of the inner tube. The grasping device is provided at its upper end with funnelshaped extensions 25 and 26, whereby the entry of the lead 14 is facilitated. The lower end has likewise an extension 27. Between the extensions 26 and 27 cylindrical grasping suryfaces 51 are arranged, the length of which is `Chips of lead cannot at least 1.5 times the diameter of the lead. To press the grasping device 19, 20 together, an axially movable grasping ring 28 is provided, which has a tubular extension 30 engaging with a grasping cone 29 over the conical end of the grasping members 19, 20. As a result of this arrangement the actual grasping means is placed as near as vpossible tothe point of the pencil. The end consists of two parts, a springy, slotted and stepped inner part 31 and a rigid outer nosepiece` 32, which retains the` former loosely-held part '31, so that its elasticity is not overstrained and cannot weaken. This part 31. is relatively long and very lightly springy, being slit longitudinally into two or `more tongues which are spaced slightly inwardly from the inner surface of the surrounding nosepiece 32, by a distance so small that it does'not appear in the drawings. impede the elastic action and are easy to remove upon removal of the nosepiece 32 and the part 31. Further,'the nosepiece 32 surrounds the part 31 in such a way, that the latter is held tightly in a central position when the nosepiece is screwed on to a thread 33 on the tube 2, whereby the grasping device is also guided and breakage of the lead 14 is prevented. The part 31 is fixed, after screwing on the nosepiece 32, between the shoulder 16 of" the sleeve 15 and a projection 34 of the nosepiece. Further the shoulder 16 serves also as upper stop for the grasping ring 28 which is pressed upward by a spring 35, while the shoulder 36 of the part 31 acts as the lower stop. Instead of the pressure spring a .tension spring can also be arranged. The extension 30 of grasping ring 28 slides in the cylindrical space 37 of the part 31 and prevents the springv 35 from entering this space. The spring 35 ls fixed. to the grasping ring 28 and therefore cannot be lost when the parts are disassembled. l

The action is as follows: Y

In the position of the parts shown in Fig. 1,

the grasping members 19, 20 are shoved upward by the spring 10 acting on the pushing tube. They are thereby pressed together by the grasping ring 28-30 and hold the lead 14 tightly clamped, since as a result of' ther'lateral freedom of movement,

2, and is provided at the grasping parts can grip the lead with their entire cylindrical surface. the sleeve 15, as already mentioned, serves as the-upper stop for the grasping ring 28, while, when the graspingdevice is empty, the sleeve 18 is drawn upward by the spring 10 to the stop 1'7. By pressing down the cap '7 the inner tube 9 with the grasping members 19, 20 and with them the grasping ring 28-30 is brought into the position shown in Fig. 2, whereby the 'lead' 14 is pressed forward the distance 38. The grasping ring 28-30 then rests on the stop 36. On further downward movement of the cap 'l the grasping members 19, 20 are pushed out of the grasping ring 28-30 the latter immediatelysnaps back by means of the spring 35 into-its normal position (see the dotted position 'of the ring in Fig. 2). The members 19, 20 are now quite loosely movable by themselves and release the lead 14 positively in every case. f

The portion of part 31, which surrounds and continuously presses on the lead, thereby prevents the lead from falling out. When the cap '7 is again released all parts return to the original position shown in Fig. 1, in which the lead is again gripped by means of the grasping members 19, 20 and the ring 28-30.

return the combined gripping action of the elastic portion 50 and the elastic tongues 12 of the sleeve l1 prevent the lead 14from being drawn back. The latter remains in is then held by means of the grasping members 19, 20. Pressure against the point of the lead increases the clamping. The further ladvance of the lead is obtained by again pressing the cap '7. The lead can easily be pushed back when the cap and grasping device are in the lowest position, since then theelastic tongues 12 are also opened by the cam surfaces 39 on the upper ends of the slots 13. The shoulder 1'7, as mentioned, prevents the grasping members from being drawn too far into the ring' 28--30 when the grasping device is empty, while the grasping members 19, 20 are prevented from being pressed too far forward into the space 37 of the nosepiece by the sleeve 18 meeting the ring 28 and with it, the projection 36; thus the grasping device cannot strike the elastic part 31, 'and possibly be damaged, When the lead 14 is used up, the grasping members 19, 20 cannot fall together, because their projections 23 overlap the projecting rim 24 of the tube 9. vA contraction of the upper opening of the grasping device, whereby the entrance of the lead could be hindered, is thus prevented.

When the nosepiece 32 is unscrewed; all movable parts for feeding the lead are made accessible and can then be inspected and cleaned easily.

As shown'in' Figs. 5 and 6 a modification of the upper grasping device may consist of elastic tongues 40, fixed to the tube 2 which project through slots 41 `of the inner tube 9 and hold the lead 14 fast. A clamping ring 42 serves to press the tongues 40 together and is controlled by the ringshaped stops 43, 44 of the tube- 9.

As shown in Figs. 7 and 8, the elastic tongues 45 are released when the inner tube is in upperposition by a ring 46, which is controlled by stops 47, 48 on the inner tube 9.

We claim:

1. In an automatic lead pencil, the combination of a casing, means adapted to grip a leadprotruding through the nose of the pencil, a tubular pushing member for containingthe lead and'operable The shoulder 16 of iand thereby released so that the advanced position andfrom the exterior of the pencil, and a plurality of grasping members each loosely connected substantiallly at its rear end to the tubular pushing member so as to allow free movement in all lateral directions through a limited range between sail grasping means and said pushing member.

2. In an automatic lead pencil, the combination of a casing, a tubular pushing member operable from the exterior of the pencil, and means for grasping and advancinga lead relatively to said casing, said means embodying an annular member and a plurality of freely and independently movable elongatedgrasping fingers, sad grasping fingers being loosely connected to said pushing member for lateral movement relatively thereto in any direction.

3. In an automatic lead pencil, the combination of a casing, a tubular pushing member, means to grip a lead protruding through the nose of the pencil, and grasping means embodying a springactuated annular member, and a plurality of independent grasping members, which are connected to the pushing member so as to allow free lateral movement between said grasping members and said pushing member.

4. In an automatic lead pencil, the combination with a casing, a tubular pushing member, and lead grasping means operatively connected to saidv pushing member,- of an annular member controlling clamping and releasing action of said grasping means and movable back and forth within said casing, stop means positively limiting movement of said annular member in both directions, and a spring acting on said annular member tending to move it to normal position after the grasping means has been released.

5. In an automatic lead pencil, the combination with a casing, a pushing member, and lead grasping means operatively connected to said pushing member, of an annular member movable back and forth within the casing and carrying a tubular extension which controls clamping and releasing action of said grasping means, and a spring acting on said annular member and arranged on the exterior of said tubular extension.

6. In an automatic leadpencil, the combination with a casing, a pushing member, and means adapted to grip a lead protruding through the nose of the pencil, of grasping means operatively connected to said pushing member and embodying one or more grasping members each extending a material distance along and having a bearing of substantial area on the pencil lead, an annular member controlling action of said grasping members, and spring means for actuating said annular member, said grasping members having portions standing in loose contact with the pushing member and adapted to hold said grasping members in proper position for feeding lead through said grasping means while permitting said grasping members to move freely to a limited extent in any transverse direction.

7. In an automatic lead pencil the combinaof a casing, a tubular pushing member, means operatively connected to said pushing member for grasping a lead and advancing it forwardly, said means embodying a plurality of grasping members and an annular member movable back and forth to control action of said grasping members, and a member having an elastic portion adapted to grip the lead protruding through the nose of the pencil, said last named member extending rearwardly from said nose and constituting a stop for limiting movement of said annular member in one direction.

3 8. An automatic lead pencil comprisinga casing and means adapted to force a leadl forward relatively to said casing, said means embodying a pushing member mounted for backward and forward movement within said casing, one or more grasping members operatively connected to said pushing member, an annular member controlling action of said grasping members and also mounted for movement backward and forward within said casing, spring means tending to move said annular member in one direction, stop means acting on said annular controlling member to limit its motion, and additional stop means acting on said pushing member and allowing the latter to travel over a somewhat greater distance than said annular controlling member. 9. In an automatic lead pencil the combination of a casing, a pushing member operable from the exterior of the pencil, means operated'by said pushing member for grasping and advancing a lead, elastic means adapted to grip the lead, and a jacket extending over said elastic means, to hold it in proper position and attached to the casing.

10. In an automatic lead pencil, the combination of a casing, and means adapted to protrude a lead through the nose of the pencil, said'means including a pushing member operable by hand from the exterior of the pencil, and grasping means operatively connected to said pushing member for grasping and advancing the lead, said grasping means including a plurality of fingers each extending a material distance along and having a bearing of substantial area on the pencil lead, each of said fingers being connected to the pushing member so as to allow free lateral movement of said fingers to a limited extent in all directions transversely of the pencil.

11. A lead pencil comprising a casing, operating means accessible from the exterior of said casing and capable of backward and forward reciprocation, a plurality of grasping fingers each loosely hung at one end on said operating means for bodily movement therewith in both directions and mounted for movement toward and away from a pencil lead and also in a lateral direction at right angles to said movement toward and away from a lead, and means effective upon a backward reciprocation of said operating means to clamp said fingers upon said lead and to maintain said fingers clamped thereon during a part of a subsequent forward reciprocation so that said lead may be advanced thereby relatively to said casing.

12. A lead pencil comprising a casing, operating means accessible from the exterior of said casing and capable of backward and forward reciprocation, a plurality of grasping fingers each loosely hung substantially at its rear end on said operating means for limited universal movement including movement toward and away from a pencil lead, said fingers having portions tapered to increase in external size in a direction from the rear ends of the fingers toward their forward ends, a clamping member extending around said fingers for cooperation with said tapered portions, resilient means normally tending to move said clamping member toward said rear ends of said fingers and abutment means rearwardly of said clamping member for Contact therewith when said ngers and operating means are drawn rearwardly, so that such rearward movement will tend to move said tapered portions through said clamping member to clamp said fingers on said pencil' lead.

13. A lead pencil comprising a casing, operating means accessible from the exterior of said casing and capable of backward and forward reciprocation, a plurality of grasping fingers operatively connected to said operating means and mounted for movement toward and away from a pencil lead,.said fingers having portions tapered to increase in external size in a direction from the rear ends of the fingers toward their forward ends, a clamping member extending around said x advanced to their forwardposition so that said fingers for cooperation with said tapered portions, resilient means tending to move said clamping member in a direction rearwardly of said fingers, abutment means rearwardly of said clamping member for contact therewith so that rearward movement of said operating means and said ngers will tend to move. said tapered portions through said clamping member to clamp said fingers on said pencil lead to enable advance of said lead upon subsequent forward movement of said operating means and fingers, and abutment means forwardly of said clamping member for contact therewith when said operating member and said fingers are moved forwardly to a pre'- determined extent, to shift said clamping member along said tapered portions in an unclamping I direction to release said fingers from said lead.

14. A lead pencil comprising a casing provided with a tapered forward end having a hole through which a lead may project, operating means accessible from the exterior of said casing and capable of backward and forward movement relatively to the casing, a plurality of lead grasping members each loosely connected adjacent its rear end to said operating means to move backward and forward therewith and capable of free movement in all lateral directions through a limited range, said members extending from said rear ends forwardly/along the pencil lead and having near their forward ends external suri vfaces tapered to expand in a direction towar said forward ends, said forward ends projectin into the tapered forward end of the casing whe said operating means and grasping members ar grasping members grasp the lead relatively close `to its projecting end, a clamping member surrounding said grasping members and movable back and forth along them for cooperation with said tapered surfaces to clamp said grasping` members onto saidl lead, and resilient means tending to move said clamping member in an unclampin'g direction along said grasping members.

l5. An automatic lead pencil comprising a casing having a nose at its forward end, a tubular pushing member operable from the exterior of the casing,`and means for grasping a lead and advancing it relatively to said casing and protruding it through said nose, said means embodying an annular member and a plurality of freely and independently movable grasping members, each of said grasping members being loosely hung substantially at its end remote from said nose. on said pushing member for lateral movement relatively thereto in any direction.

y AUGUST LEISTENSCHNEIDER.

KONRAD KRESSEL.

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