US2893352A - Pencil sharpener - Google Patents

Description

July 7, 1959 l.. o. HEDBLOM PENCIL SHARPENER Filed July 28. 1958 IIII VIIIIA JNVENToR.

LAKS 0. HEDBLCM A7 rraRA/EY United Sates Patent PENCIL SHARPENER Lars 0. Hedblom, Detroit, Mich., assign'or of one-half to Larry Atiyeh, Detroit, Mich.

Application July 2s, 195s, serial No. 751,226

s claims. (ci. 1z0- 96) This invention relates to pencil Sharpeners, and more particularly to a pencil Sharpener for draftsmen, engineers or artists.

Heretofore most pencil Sharpeners cut or grind a conical end upon a pencil, including the projecting lead.

It is the object of the present invention to provide a novel pencil Sharpener which will shape the lead in a narrow elongated form of rectangular shape in cross section. v

It is a further object to provide a pencil Sharpener which grinds the Wood covering in the form of a wedge, but grinds the lead as an elongated relatively thin strip of rectangular shape in cross section.

It is a further object to provide a novel and inexpensive pencil Sharpener with a pair of rotatable tubular members, each carrying cutting blade defining discs and wherein the tubes rotate in unison, but are nevertheless supported on oppositely threaded screw means by which the said discs may be manually adjusted with respect to each other and further incorporating means whereby once adjusted, said tubes may be rotated with respect to the pencil Sharpener housing and fixedly retained against longitudinal movement.

These and other objects Will be seen from the following specification and claims in conjunction with the appended drawing in which:

Fig. 1 is a vertical section of the pencil Sharpener.

Fig. -2 is a section taken on line 2-2 of Fig. l.

Fig. 3 is a section taken on line 3-3 of Fig. 2 on a Slightly increased scale.

Fig. 4 is a fragmentary elevational view illustrating the shape of the pencil lead using the present Sharpener.

Fig. 5 is a side view thereof.

It will be understood that the above drawing illustrates merely a preferred embodiment of the invention and that other embodiments are contemplated within the scope of the claims hereafter set forth.

Referring to the drawing, the present pencil Sharpener has a hollow housing including front and rear halves 11-12 suitably secured together at their meeting edges.

Housing half 11 has a forwardly extending ridge 10 on housing half 12. By this construction one die Suicesfor housing halves 11 and 12.

The dome shaped portions of said housing terminate at the front and rear in the upright walls 14. Said housing halves include registering upright end wall elements 13 which are centrally apertured. The above ridges 10 project from the edges of elements 13. Said housing includes the registering horizontal bottom wall elements 15, each of which has an elongated aperture therethrough defining opening `16. A plurality of threaded apertures 17 are also formed through said bottom wa'll elements.

The assembled housing halves are mounted on rectangular support plate 18 which is secured to the respective bottom wall element 15 .of said housing halves by a series of screws 19. Plate 18 and screws 19 maintain the assembled relation of said housing halves.

Plate 18 has additional apertures 8, by which the pencil Sharpener may be mounted and secured upon a table or other support. Said platform or plate has formed therethrough rectangular `aperture 20 in registry with bottom wall aperture 16.

Inwardly directed elongated \bosses 21 in opposed spaced relation are projected downwardly from plate 18 and include the opposed parallel undercut Slots 22. Removable rectangular lbox 23 is positioned directly below plate 18 and includes at its upper open end the elongated laterally extending flanges 24 which slidably project within slots 22 to Support box 23 directly below apertures 16 and 20.

Stop flange 25, Fig. 2 is arranged upon the undersurface o-f plate 18 and limits inward positioning of box 23 so that its upper open end is in registry with apertures 16 and 20.

Semi-circular bosses 26 project inwardly and outwardly respectively from the central edge portions of the respective end wall elements 13 and have formed therein semicircular grooves 27 which supportably receive the outer race of the respective ball bearings 28. These are supportably retained within said bosses upon assembly of housing 11-1213 and 15.

Transverse horizontally disposed sleeve 29 is rotatively journaled through the inner race of one of the ball bearings 28 and has an internal ,bore 30. Said tube has a central reduced portion 31 with a reduced internal bore which is threaded at 32 for threaded engagement with threads 33 of one hand upon elongated shaft 34 which extends through sleeve 29.

A second horizontally disposed tube 36 is aligned with tube 29 and is rotatively journaled within the second ball bearing 28 upon the opposite upright side wall 13 and extends into the interior of said housing.

Said tube Similarly has the internal bore 37 which loosely receives a portion of Shaft 34. Tube 36 also has a reduced sleeve portion 38 with a reduced bore threaded at 39 and in threaded engagement with threads 35 on shaft 34, which threads are of the opposite hand from threads 33 spaced therefrom on said shaft.

Handle 40, Fig. l, terminates in the hub 41 which projects over the outer end of tube 29 and is split upon one side defining the free ends 41 interconnected and secured together fixedly by screw 42. Each of the tubes 29 and 36 at its inner end has an enlarged annular flange 43 which flanges are normally arranged in adjustable spaced relation with respect to each other, but are nevertheless secured together loosely for rotation in unison by the series of headed pins or rivets 44.

Each of the flanges 43 has an annular groove 45 therein adapted to fixedly receive the parallel spaced central portions 53 of the discs 46 for effecting rotation thereof.

The parallel central portions 53 terminate in the diverging outer portions 49 defining the annular groove 50 of wedge-Shape in cross section for the grinding of the tapered portions 69 of pencil 68 as in Figs. 4 and 5.

Each of the said discs throughout its annular portion 49 has a series of circularly arranged angularly inclined slits 47, Fig. 3 by which there are formed a circular series of inclined radial cutting blades 48 which are struck angularly inward from portions of said discs.

As shown in Fig. 2, there are also formed through the central circular portions 53 of said discs a circular series of inclined slits 51 from which are struck angularly inward a series of circularly arranged radial cutting blades 52 whose inner edges are in parallel spaced relation with the corresponding inner edges of a series of similar blades of the other disc.

In other words the central portion of each of the discs 3 has Va `series of struck in blades 52. in parallel spaced relation whereas the diverging portions 49 of said discs have formed therein a series of inwardly struck angular blades 48. The inner cutting edges of blades 48 of the two discs are in acute angular relation to each other respectively.

Blades 52 are adapted to form the rectangular flattened lead portion 70 of Figs. 4-5, whereas the tapered blades 48 form the wedge-shaped wood portions 69 on pencil 68.

The housing halves 11-12 upon assembly define the upright apertured boss 54, the longitudinal bore 55 of which is hexagonal in cross section to cooperatively and guidably receive the similarly shaped pencil 68. Said pencil is projected downwardly through aperture S in the position shown in Fig. 4 to thus define between outting blades 52, the rectangularly shaped sides 70 of the pencil shown in Fig. 5.

The internal shape of boss 54 guides pencil 68, Fig. 4 to the lead cutting position for sharpening. The longitudinal axis of bore 55 is midway of discs 46 so as to correctly center said pencil with respect to the opposed sets of cutting blades 48-52 which project inwardly from the respective discs.

Boss 56, Fig. 1 is of square shape in cross section and projects from one end of shaft 34 beyond the end of ltube 36. Washer 57 has a similarly shaped central aperture for snugly and xedly receiving boss 56, and said washer is secured thereon by screw 60.

The inner annular edge of washer 57 has a series of 'Y inwardly directed notches 58 adapted to cooperatively and retainingly receive a corresponding series of outwardly extending projections 59 on shaft 34 for interlocking washer 57 with tube 36. Accordingly rotation of handle 40 and the attached tube 29 effects rotation in unison of tube 36 as well as attached shaft 34 which extends through both of tubes 29 and 36. Accordingly shaft 34 rotates in unison with both tubes 29 and 36 during normal sharpening operations.

Tube 36 has an annular groove 61 in its exterior surface adapted to receive one edge of grooved retainer plate 62. The upper free end 63 of said plate snugly projects into an undercut groove 64 in the horizontally apertured block 65. Said block is adjustably secured upon the exterior of housing 11-12 by the elongated screw 66 which extends through block 65. Said screw extends through threaded opening 67 in housing wall 13. Block 65 is adjustably secured upon screw 66 by set screw 68.

In operation with retainer plate 62 iixedly mounted as shown on said housing, its lower end retainingly engages tube 36 for preventing longitudinal movement thereof relative to said housing during rotation. Likewise as tube 36 is xedly secured to shaft 34, said shaft is also restrained against endwise movement relative to said housing and with respectto tubes 36 and 29 during normal operation of the pencil' Sharpener.

Should it be desired to adjust the spacing between discs 46, all that is necessary is to disengage washer 57 from tube 36, either by its complete removal on removal of screw 60 or merely by such loosening of screw 60y as will permit longitudinal disengagement of washer 57 from said tube.

Tubes 29--36 are restrained against rotation by holding handle 40 irnmovably, and at the same time retainer plate 62 is disengaged from tube 36; Shaft 34 is rotated by applying a wrench to boss 56. Due to the opposite leads of threads 33-35 this'will elfect simultaneous longitudinal movement of the two discs 46 either towards or away from each other, depending upon the ,direction of lrotation of shaft 34.

Once the desired spacing between said discs is achieved, washer 57 is reassembled to interlock shaft 34 with sleeve 36. Thereafter set screw 68 is loosened and block 65 slid on screw 66 until the depending retainer plate 62 again registers within tube slot 61. At this point the setscr'ew is againtightenedY for anchoring block 65 upon screw66.I

Thereafter manual rotation of handle 40 will effect simultaneous rotation of tubes 29-36, the shaft 34, as well as the xedly attached blade defining discs 46.

Regardless of the adjustment of said tubes and the attached discs, the construction is such that the longitudinal axis of the pencil receiving boss 54 will be midway of discs 46 to assure proper location of the pencil to be sharpened.

In this connection the headed pins 44 loosely engage and interconnect flanges 43 of the respective tubes to permit the above described relative adjustments without interfering with the driving relation between said tubes.

The present construction provides a means of accurately adjusting the spacing between the opposed sets of blades 52 for determining the thickness of the lead as at 70, Figs. 4 and 5. Thus simultaneous micromatic adjustments of discs 46 with respect to each other may be made, after which shaft 34 is secured at its end to tube 36. Accordingly, the Sharpener will cut the predetermined thickness in the lead as at 70 until there has been another adjustment of discs 46, depending upon the needs of the draftsman.

The main advantage of the present Sharpener is to Vdraftsrnen because it eliminates all of the previous effort required to form the lead of the drafting pencil to the `shape shown in Figs.V 4 and 5 Having described myinvention, reference should now be had to the following claims.

I claim:

1. A pencil Sharpener comprising a housing including upright apertured end walls, a pair of aligned tubes each respectively journaled through an end wall and projecting into said housing with their inner ends in adjustable spaced relation, means loosely interconnecting the inner ends of said tubes for rotation in unison, a handle secured to one tube, a pair of spaced discs centrally secured to the inner ends of said tubes respectively, central portions of -said discs being parallel and terminating in diverging outer portions, a circular series of inclined radial blades struck angularly inward from the central portion of each disc, a second circular series Yof elongated inclined radial blades struck angularly inward from the diverging portion of each disc, an apertured pencil receiving boss projecting from said housing with its longitudinal axis midway of said discs, means on said housing retainingly engaging one of said tubes against longitudinal movement, and an elongated shaft extending through said tubes and adjustably secured thereto respectively.

2. The pencil Sharpener of claim 1, and means iixedly securing said shaft to one tube for rotation therewith.

3. The pencil Sharpener of claim 1, said shaft having a pair of oppositely threaded portions in threaded engagement with similar threaded portions of said tubes respectively, whereby rotation of said shaft and at the same time restraining said tubes against rotation effects longitudinal adjustment of said discs relative to each other.

4. The pencil Sharpener of claim l, a boss of square cross sectional shape projecting from one end of said shaft, and a similarly apertured washer positioned over said boss, secured to said shaft, and interlocked with the endV of one tube.

5. The pencil Sharpener of claim 1, annular enlarged flanges on the adjacent inner ends lof said tubes xedly receiving and supporting said discs, said means interconnecting said tubes including a plurality of spaced headed pins loosely extending longitudinally between said anges. j

6. The pencil Sharpener of claim l, said means retainingly engaging one of said tubes including a slotted block, there being an annular groove in an adjacent tube, an upright locking plate with one end anchored :in said block and its other end nested in said annular groove, and a. screw adjustably secured to said block 5 and adjustably threaded through an end wall of said housing.

7. The pencil Sharpener of claim 1, said apertured end walls each including an elongated boss projecting from opposite sides thereof and having an internal annular groove and ball bearing nested in said groove support ably journaling a tube.

8. The pencil Sharpener of claim 1, the inner series of blades respectively extending at an acute angle to the respective outer series of blades.

References Cited in the le of this patent UNITED STATES PATENTS Gerwig Apr. 14, 1942 FOREIGN PATENTS Germany Sept.k 20, 1919 Germany Oct. 31, 1951

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