US3667516A

US3667516A - Apparatus for sharpening leads for pencils or the like

Info

Publication number: US3667516A
Application number: US23312A
Authority: US
Inventors: Robert M Grosjean
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-27
Filing date: 1970-03-27
Publication date: 1972-06-06
Anticipated expiration: 1989-06-06

Abstract

A disposable, expendable sharpener for leads and a drive for manipulating and rotating the sharpener are provided. The sharpener includes a bottom wall, side wall, and central truncated cone or hub which are integrally formed of foamed plastic material. A top is provided for the sharpener with an opening for access to a truncated conical abrasive surface in the sharpener. A flexible lip extends from an edge of the top toward the abrasive surface to urge a lead inserted in the opening against the surface. The lip tends to enclose the sharpener to restrict spreading of graphite powder therefrom and also wipes graphite powder from the lead when being sharpened and when removed. The drive for the sharpener includes a gear arrangement which causes the sharpener to move in a circular path and, at the same time, to rotate about its own axis, with a vertical line through the conical abrasive surface of the sharpener being stationary. This line represents the position at which the lead is inserted for sharpening, which is accomplished without need for rotating or otherwise manipulating the lead.

Description

[451 June 6, 1972 United States Patent Grosjean [54] APPARATUS FOR SHARPENING LEADS 924,360 8/1947 France..................................144/288 FOR PENCILS OR THE LIKE Primary E.xaminerAndrew R. Juhasz Assistant Examiner-James F. Coan Attorney-Allen D. Gutchess, Jr.

[72] inventor: Robert M. Grosjean, 4625 Merry Lane,

Toledo, Ohio 43615 Mar. 27, 1970 [57] ABSTRACT.

A disposable, expendable sharpener for leads and a drive for [22] Filed:

21 Appl. No.:

manipulating and rotating the sharpener are provided. The [52] [1.5. Cl........................144/28.l1, 144/287, l44/28.72, sharpener includes a bottom wall, side wall, and central truncated cone or hub which are integrally formed of foamed plastic material. A top is provided for the sharpener with an opening for access to a truncated conical abrasive surface in the sharpener. A flexible lip extends from an edge of the top 3.8, 3.9; 51/181 toward the abrasive surface to urge a lead inserted in the 5s FieldofSearch...................144/28.1

opening against the surface. The lip tends to enclose the shar- References Cited pener to restrict spreading of graphite powder therefrom and also wipes graphite powder from the lead when being shar- UNlTED STATES PATENTS pened and when removed. The drive for the sharpener includes a gear arrangement which causes the sharpener to move in a circular path and, at the same time, to rotate about its own axis, with a vertical line through the conical abrasive surface of the sharpener being stationary. This line represents the position at which the lead is inserted for sharpening, which 3,223,073 Mamin..................................144/28.l 3,398,773 ....144/28.1 2,189,476 ....l44/28.7

8/1968 Dahle 2/1940 3,276,434 10/1966 Siggelko FOREIGN PATENTS OR A CA is accomplished without need for rotating or otherwise manipulating the lead.

Germany..

19 Claims, Drawing Figures Great Britain........................

PATENTEDJUH s 1972 3, 667', 516

sum 1 OF 3 INVESTOR A 055 M msam/ firm/may APPARATUS FOR SHARPENING LEADS FOR PENCILS OR THE LIKE This invention relates to a device for sharpening leads and to a drive mechanism therefor. 4

Various sharpening devices for sharpening points of pencil leads, particularly of the type used by draftsmen, are well known in the art. Heretofore, the sharpeners have been of a permanent type with replaceable sand paper often used to form the abrasive surface of the sharpener. Such sharpening devices have had to be cleaned from time to time, which is a messy operation, particularly because of the powdered graphite collected in the devices. The powdered graphite readily marks any surface with which it comes into contact and smears easily, rendering it difficult to clean. The powder is easily dispersible over a wide area to further render cleaning difficult. Also, during cleaning of the sharpener or replacement of the sand paper, ones fingers are easily soiled whichfurther tends to spread the graphite. In addition to these difficulties, the cleaning operation is also time-consuming, usually requiring to minutes of the draftsmans time.

The sharpening devices as heretofore known have been constructed with open tops which are necessary to admit the lead and enable it to be manipulated in a circle as it is sharpened. With the open top, however, there is an ever present danger of the device being upset with the contents being dispersed.

Heretofore, after the lead was sharpened, it was necessary to remove the powdered graphite therefrom which -was produced during the sharpening. When the lead was cleaned with a rag, the rag would soil other surfaces with which it came into contact. Another common technique for cleaning the lead was to jab it into a block of foam plastic material. In this instance, part of the powdered graphite was simply pushed farther up the lead and, subsequently, could fall on a drawing on which the pencil was used. Part of the remainder of the graphite laid on the surface of the block to readily soil anything with which it came into contact. In any event, the cleaning operation for the lead required another step and additional time for the overall sharpening process.

The present invention relates to a disposable, expendable sharpening device for leads for pencils and the like which overcomes the above difficulties. The new sharpening device is inexpensively made so as to be simply thrown away when desired, as when the abrasive surface becomes worn or the device becomes excessively full of graphite powder and other particles. Consequently, there is nothing to clean, with the resulting danger of spreading of the powder also being eliminated. Further, the sharpening device has a top which encloses a substantial portion of the device with a lip extending inwardly from the top which further closes off the device, rendering accidental dispensing of the contents almost impossible, even though the device may be upset. The resilient lip helps to urge the lead against the abrasive surface during the sharpening operation. The lip also wipes off the lead as it is being sharpened and as it is removed from the sharpener to clean it of the powdered graphite. Hence, when the lead is removed, it is instantly ready for use with no additional cleaning operation usually required.

The new sharpening device also has a power drive which enables the device to move in a manner such that a lead inserted thereinto is sharpened without any circular or rotary movement required at all of the lead. For this purpose, the sharpening device rotates about its own center and at the same time moves in a circular path around an axis which passes through the abrasive surface. To achieve this motion, the sharpener device has a central shaft extending therebelow with a rotatable gear thereon. An arm is rotatably connected to and extends transversely from the central shaft and, in turn, is con I the rotatable gear causes rotation of the central shaft and the device on its own axis as it meshes with and moves in a circular path around the stationary gear.

7 ing device for leads and the like which will not disperse its contents, even if upset.

A further object of the invention is to provide a sharpening device for leads having a resilient lip which urges the lead to be sharpened against an abrasive surface of the device and cleans the lead as it is sharpened and removed.

Yet a further object of the invention is to provide a sharpening device for leads having a drive arrangement for moving the device in a manner such that the lead can be inserted and held stationary when being sharpened.

Still a further object of the invention is to provide a drive arrangement for a sharpening device which causes the sharpening device to move in a circular path and at the same time to rotate about is own axis.

Many other objects and advantages of the invention will be apparent from the following detailed description of preferred embodiments thereof, reference being made to the accompanying drawing, in which:

FIG. 1 is a somewhat schematic, overall view in perspective of a sharpening device and a drive arrangement therefor embodying the invention;

FIG. 2 is an enlarged perspective view of the sharpening device of FIG. 1, taken through a central cross-section thereof;

FIG. 3 is a top view of the sharpening device;

FIG. 4 is a perspective view of a modified sharpening device embodying the invention, taken through a central cross section thereof;

FIG. 5 is a view in horizontal cross section, taken along the line 5-5 of FIG. 4;

FIG. 6 is a view in perspective of the sharpening device shown in dotted lines and the drive arrangement of FIG. 1; and

FIG. 7 is a somewhat schematic top view of the sharpening device and drive arrangement of FIG. 6, illustrating the motion of the device.

Referring to the drawings, and particularly to FIG. 1, a sharpening device for sharpening or pointing leads of pencils and the like is indicated at 10 and is supported and driven by a drive mechanism indicated generally at 12. However, rather than using the drive mechanism, the sharpening device can be held stationary and the lead manually inserted, rotated, and manipulated to effect the sharpening, in a manner known in the an, The sharpening device 10 includes a one-piece lower unit or container indicated at 14 (FIG. 2), preferably molded of a lightweight, low cost foamed plastic material, such as Styrofoam. The lower unit 14 includes a circular bottom wall 16 having an annular upper surface 18, with an integral, central, truncated conical member or hub 20 and an integral, outer side wall 22 of circular cross section. An annular plastic top or cover 24 is suitably supported above the upper edge of the outer wall 22, and extends inwardly to a circular edge 26, stopping short of the truncated conical hub 20. An annular sheet 28 of resilient, flexible material is suitably affixed to the top 24 and projects inwardly therefrom to form a resilient, flexible annular lip 30. The lip 30 has an inner circular edge 32 with a diameter substantially equal to that of the upper end of the truncated conical hub 20, but preferably slightly smaller, to bear'against the surface with light pressure. However, the dimensions are such that when a lead, indicated in dotted lines at 34, is extended vertically into the device 10 and into engagement with an abrasive surface 36, the lip 30 will be deformed downwardly somewhat, and will urge the lead 34 against the surface 36 as the lip tends to return to its original position.

The abrasive surface 36 preferably is formed by a sheet 38 of sand paper which can be affixed directly to the hub 20 by suitable adhesive. If desired, a resilient foam layer 40 can be located therebetween to enable the surface 36 to yield slightly under the pressure of the lead 34 and provide more uniform contact with the lead. Rather than sand paper, the abrasive surface 36 can be achieved by coating the outer surface of the hub 20 with an adhesive and then applying abrasive particles thereto.

The resilient lip 30 not only urges the lead 34 against the abrasive surface 36, but also wipes the lead 34, as it is sharpened and also as it is removed from the device 10. For this purpose, the lead can be rotated slightly as it is raised. Consequently, the lead 34 is fully ready to be used when removed, without the necessity of further wiping ofi the powdered graphite with a rag or'foam block which requires an additional operation. The rag or block can then soil surfaces on which they rest or which come into contact therewith. Further, the graphite is not pushed up on the lead and allowed to remain as is the case when the foam block is used.

.The lip 30 also substantially closes off the device in cooperation with the top 24. Consequently, if the device 10 is upset, graphite powder or other material therein will not be spilled. With the upper wall 24 sloping downwardly and inwardly slightly, the material will tend to be directed away from the contact between the hub and the resilient lip even if turned upside down.

When the abrasive surface 36 is worn to the extent that pointing the lead 34 becomes excessively slow, or should the annular cavity formed by the unit 14 and the top 24 first become excessively full, the device 10 can simply be thrown away without the necessity of being cleaned, eliminating the resulting soiling of surfaces and hands and the concomitant time-consuming clean-up encountered with Sharpeners heretofore known.

Referring now to FIGS. 4 and 5, a modified sharpener embodying the invention is indicated at 42 and includes a lower unit or container 44 and an upper driving and guiding unit or member 46. The unit 44 preferably is molded of lightweight foamed plastic material which is disposable. It includes a circular bottom wall 48, an integral, central, truncated conical member or hub 50, and an integral, outer side wall 52 of circular cross section. A plastic top or cover 54 is suitably affixed to the upper end of the hub 50 as by adhesive and extends outwardly therefrom to a circular edge 56, stopping short of the outer wall 52.

An annular sheet 58 of resilient, flexible material is suitably affixed to the top 54 and projects outwardly from the edge 56 to form a resilient, flexible annular lip 60. The lip 60 has an outer circular edge 62 with a diameter substantially equal to the diameter of the adjacent portion of the outer wall 52 but preferably slightly larger, to bear against the inner surface of the wall with light pressure. The dimensions are designed so that when a lead, indicated at 64, is extended vertically into the device 42 and into engagement with an abrasive surface 66, the lip 60 will be deformed downwardly somewhat and urge the lead against the surface.

The abrasive surface 66 can be formed by a sheet 68 of sand paper which can be affixed directly to the wall 52 by suitable adhesive or which can have a thin resilient foam layer, similar to the layer 40, located between the sand paper sheet 68 and the inner surface of the wall 52. This enables the surface 66 to yield somewhat under the pressure of the lead 64 to provide more uniform pressure on the lead, particularly if the position of the lead relative to the abrasive surface tends to vary as the lead is rotated and manipulated in order to be sharpened. However, the outer wall 52 itself is somewhat flexible and will usually be sufficiently yieldable to provide the desired result without the additional resilient layer. Again, as in the embodiment of FIGS. 1-3, the abrasive surface 66 can be achieved by coating the inner surface of the wall 52 with an adhesive and then applying abrasive particles thereto.

The resilient lip 60 functions similarly to the lip 30, urging the lead 64 against the surface 66. The lip 60 also wipes the lead 64 as it is sharpened and as it is removed from the sharpener 42. Also, the lip edge 62 preferably contacts the surface 66 and closes .off the container 44 to prevent spreading the graphite if the device is upset.

The sharpening device 42 can be driven by mechanism similar to that employed with the device 10. For a less expensive device, however, the plastic driving and guiding unit 46 can be employed. This unit is made of a thin-walled plastic material which may be molded sufficiently inexpensively that the guide unit 46 can be disposed of with the lower unit 44 when desired. However, the unit 46 can be retained and used with another one of the lower units 44.

The unit 46 includes a hollow cap member 70 having a thin outer wall 72 extending downwardly close to the upper end of the outer wall 52 of the lower unit 44. A recess 74 is molded into the cap member 70 and is shaped with a taper to receive the end of a lead holder or pencil, shown in dotted lines at 76. A guide opening 78 in the bottom of the recess 74 receives the lead 64 and directs it into engagement with the abrasive surface 66 and the resilient lip 60. The cap also has an integral central hub 80 extending downwardly and forming a tapered shaft 82 which is rotatably received in a tapered passage or bore 84 in the hub 50 of the lower unit 44. A shoulder 86 is formed between the hub 80 and the shaft 82 and preferably bears against an annular bearing member or washer 88 which is supported on the cover 54 above the hub 50. The lower end of the shaft or axle 82 extends below the lower end of the bore 84 into a shallow recess 90 formed by the lower wall 48 of the unit 44. A push nut 92 engages the lower end of the axle 82 and retains the driving and guiding unit 46 in place with respect to the lower unit 44.

To sharpen the lead 64, it is extended from the holder 76 a suitable amount, in the order of one-half to three-quarter inch, and then inserted through the hole 78 and into contact with the abrasive surface 66. The cap member 70 is then rotated by pushing the holder 76 to cause the lead to be sharpened as it rides around the surface 66.

Referring now more particularly to the overall drive mechanism 12 of FIGS. 6 and 7, a support housing or base 94 contains a small electrical motor connected by a suitable internal gear train to a drive shaft 96 extending upwardly from the base. An arm 98 is affixed to an upper portion of the shaft 96 above the base 94 by suitable set screws 100 engaging the shaft which is positioned in a hole 102 of the arm. At an outer portion of the arm 98, a central shaft 104 is rotatably mounted and extends upwardly to be centrally afiixed in the sharpener l0 and specifically in the hub 20 thereof. To achieve this, the shaft 104 has a shoulder abutting the bottom of the hub 20 and a push nut 105 (FIG. 2) on top of the hub. The sharpener 10 is thus frictionally held on the shaft 104 for rotation therewith. Alternately, the shaft 104 can be affixed in the hub 20 with suitable non-circular projections extending therefrom to provide a better connection between the hub and the shaft. The shaft 104 positions the dispenser with the lower surface of the bottom wall 16 slightly above the arm 98. The shaft 104 also extends downwardly below the arm 98 to a small pinion gear 106 suitably affixed to the shaft. A large stationary gear 108 is mounted on the base 94 concentrically with respect to the drive shaft 96 and is continuously in engagement with the gear 106.

In operation, when the drive shaft 96 is rotated, the arm 98 rotates and moves the sharpener 10 in a circular path, being shown in several dotted line positions in FIG. 7, the center of which path is coaxial with the axis of the shaft 96. During the entire movement of the sharpener 10 in the circular path, the gear 106 meshes with the stationary gear 108 and causes the central shaft 104 of the sharpener to rotate about the axis of the shaft 104 and about the center of the sharpener 10. Consequently, the sharpener 10 moves in the manner illustrated in FIG. 7, moving in the circular path and, at the same time, continuously rotating about its own axis.

The distance between the central shaft 104 and the drive shaft 96 is equal to the distance between the center of the hub 20 and a portion of the conical abrasive surface 36. With this arrangement, the lead 34 can be inserted into the sharpener 10 directly above the shaft 96 so that it will be sharpened without any motion whatsoever of the lead, the axis of the shaft 96 always being stationary. If desired, a guide can be employed in alignment with the shaft 96 to hold the pencil and lead in this position as the sharpener rotates The guide can be supported by a bracket mounted on the housing 94.

The drive arrangement 12 can also be employed for the sharpener 42 with the central shaft 104 mounted in the passage 84 and with the

shafts

104 and 96 spaced slightly farther apart than before, equal to the distance between the axis of the hub 50 and a portion of the abrasive surface 66.

The above drive arrangement provides an effective, yet relatively low-cost, unit which further reduces the time required for sharpening the lead.

Various modifications of the above described embodiments of the invention will be apparent to those skilled in the art and it is to be understood that such modifications can be made without departing from the scope of the invention, if they are within the spirit and the tenor of the accompanying claims.

I claim:

1. A device for sharpening points of leads comprising a container having a bottom wall, a side wall, a central, upwardly extending hub, an abrasive surface, and a top having a circular edge extending toward said abrasive surface with the center of the circular edge aligned with the axis of the hub, means forming a resilient lip extending beyond said circular edge toward said abrasive surface, said lip being effective to engage a lead inserted in said container to urge the lead toward said abrasive surface.

2. A device according. to claim 1 wherein said bottom wall, side wall, hub, and top of said container are made of inexpensive plastic material, whereby said container can be thrown away when desired.

3. A device according to claim 1 characterized by said bottom wall, side wall, and hub being integrally formed.

4. A device according to claim 1 characterized by a shaft extending beyond said bottom wall of said container and being aligned with the axis of said hub.

5. A device according to claim 1 characterized by said abrasive surface being formed by a separate truncated conical sheet of sand paper positioned on said hub.

6. A device according to claim 5 characterized by a layer of resilient material disposed between said hub and said sand paper sheet.

7. A device according to claim 1 characterized by said abrasive surface being formed by a separate sheet of sand paper positioned on said side wall of said container.

8. A device for sharpening leads comprising a container having a bottom wall, a side wall, a central, upwardly extending hub, an upwardly extending abrasive surface, and a top extending toward said abrasive surface in close proximity therewith, said top having an edge terminating short of said abrasive surface to enable a lead to be inserted therebetween, said bottom wall, said hub and said side wall being made of inexpensive, disposable material whereby said device can be thrown away after use.

9. A device according to claim 8 characterized further by a resilient annular lip extending beyond the edge of said top and toward said abrasive surface.

10. A device according to claim 9 characterized by said resilient annular lip being in contact with said abrasive surface.

ll. A device according to claim 8 characterized by said abrasive surface-being on said hub, said top being afiixed to the upper edge of said side wall, and extending inwardly to a circular edge concentric with said hub.

12. A device according to claim 8 characterized further by said abrasive surface being on the inner surface of said side wall, said top being supported on said hub and said edge being circular and concentric with said side wall.

13. A device according to claim 12 characterized further by a rotatable guiding member having an opening positioned above said abrasive surface to receive a lead, and having a shaft extending downwardly therefrom, said shaft being rotatably carried in said hub, in axial ali ment therewith.

14. A device according to claim 8 c aracterized by a shaft affixed in said hub and extending downwardly below the bottom wall of said container, said shaft being in coaxial alignment with the axis of said hub.

15. Apparatus for sharpening points of leads comprising a receptacle having an abrasive surface with a circular cross section, a first shaft extending downwardly from said receptacle and aligned with the axis of said surface, an arm rotatably carrying said shaft and extending transversely thereto, a first gear affixed to said shaft, a drive shaft afiixed to said arm and spaced from and parallel to said first shaft, means for driving said drive shaft, a second gear positioned coaxially with respect to said drive shaft and meshing with said first gear, said drive shaft rotating said arm and moving said first gear around said second gear to move said first shaft in a circular path around the center of said drive shaft and to cause said first shaft simultaneously to rotate on its own axis.

16. Apparatus according to claim 15 characterized by the distance between said first and said drive shafts being equal to the distance between said first shaft and a portion of said abrasive surface.

17. Apparatus for sharpening points of leads comprising a receptacle having a tapered abrasive surface of circular transverse cross section, a shaft extending downwardly from said receptacle and aligned with an axis of said surface, means for rotating said shaft, and means engageable with said shaft for moving said receptacle in a circular path, the center of which extends through said conical abrasive surface.

18. Apparatus according to claim 17 characterized by said means for moving said receptacle in a circular path comprises an arm rotatably connected. to said shaft, and a drive shaft located at the center of the path and afiixed to said arm for moving same.

19. Apparatus according to claim 17 characterized by said means for rotating said shaft comprises a gear affixed to said shaft, and a stationary gear having a center at the center of the circular path of said receptacle and engageablewith said gear at all times as the receptacle is moved in its circular path.

Claims

2. A device according to claim 1 wherein said bottom wall, side wall, hub, and top of said container are made of inexpensive plastic material, whereby said container can be thrown away when desired.

11. A device according to claim 8 characterized by said abrasive surface being on said hub, said top being affixed to the upper edge of said side wall, and extending inwardly to a circular edge concentric with said hub.

13. A device according to claim 12 characterized further by a rotatable guiding member having an opening positioned above said abrasive surface to receive a lead, and having a shaft extending downwardly therefrom, said shaft being rotatably carried in said hub, in axial alignment therewith.

14. A device according to claim 8 characterized by a shaft affixed in said hub and extending downwardly below the bottom wall of said container, said shaft being in coaxial alignment with the axis of said hub.

15. Apparatus for sharpening points of leads comprising a receptacle having an abrasive surface with a circular cross section, a first shaft extending downwardly from said receptacle and aligned with the axis of said surface, an arm rotatably carrying said shaft and extending transversely thereto, a first gear affixed to said shaft, a drive shaft affixed to said arm and spaced from and parallel to said first shaft, means for driving said drive shaft, a second gear positioned coaxially with respect to said drive shaft and meshing with said first gear, said drive shaft rotating said arm and moving said first gear around said second gear to move said first shaft in a circular path around the center of said drive shaft and to cause said first shaft simultaneously to rotate on its own axis.

18. Apparatus according to claim 17 characterized by said means for moving said receptacle in a circular path comprises an arm rotatably connected to said shaft, and a drive shaft located at the center of the path and affixed to said arm for moving same.

19. Apparatus according to claim 17 characterized by said means for rotating said shaft comprises a gear affixed to said shaft, and a stationary gear having a center at the center of the circular path of said receptacle and engageable with said gear at all times as the receptacle is moved in its circular path.