US3115869A - Pencil sharpener - Google Patents

Description

Dec. 31, 1963 A. H. FREEMAN PENCIL SHARPENER Filed June 29, 1961 2 Sheets-Sheet 1 T6 DJQW M3 6170 by Dec. 31, 1963 A. H. FREEMAN PENCIL SHARPENER Filed June 29, 1961 2 Sheets-Sheet 2 T6 1 UmA" A03 Alia/wag United States Patent at El 3,115,869 PENCIL SHARPENER Arthur II. Freeman, Broekport, N.Y., assignor to General Electric Company, a corporation of New York Filed June 29, 1961, Ser. No. 126,623 3 Claims. (Cl. 120--95) This invention relates to pencil sharpeners, and more particularly to an electric pencil sharpener adapted to support and automatically feed the pencil being sharpened into the sharpening mechanism.

The general object of the invention is to provide an improved electrically powered pencil sharpener in which the pencil being sharpened is supported therein and is automatically rotated and advanced into the sharpening mechanism as sharpening proceeds.

Briefly stated, in accordance with one aspect of my invention I provide a pencil sharpener including a motor driven abrasive disk mounted for rotation on a horizontal axis, and pencil guiding means adjacent the disk and offset with respect to a vertical plane passing through its axis. The pencil guiding means is so arranged that a pencil may be supported in a generally vertical but slightly inclined position with its lower end in contact with a portion of the disk which moves downwardly during rotation so that a continuous downward force is exerted on the pencil by both the disk and the force of gravity. A resilient multi-fingered rotary member arranged to contact the pencil and rotate it about its longi tudinal axis is positioned adjacent the pencil guide and is connected by gearing to the sharpener motor.

The subject matter which I regard as my invent-ion is particularly pointed out and distinctly claimed in the concluding portion of this specification. My invention, however, both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view of a pencil sharpener embodying my invention, some of the parts being broken away to show details of construction;

FIG. 2 is a fragmentary cross-sectional view taken along the line-22 in FIG. 1;

FIG. 3 is a cross-sectional view taken along the line 3-3 in FIG. 2, some of the parts being broken away;

FIG. 4 is a perspective view showing certain parts of the sharpener; and

FIG. 5 is a perspective view showing another part of the sharpener.

Referring to the drawings, the numeral 1 designates the casing of an electric pencil sharpener having there-in an electric motor 2 including a horizontal shaft 3 upon which is mounted a knife sharpening Wheel 4 and a pencil sharpening disk 5. It will be understood that wheel 4 and disk 5 are mounted on opposite ends of shaft 3 and that these members are independent in the sense that either may be used to perform its intended function independently. The knife sharpening elements of the sharpener shown in FIG. 1 form no part of the present invention and need not be further described.

Motor 2 is mounted on a base plate 6 which is suitably secured to casing 1 by screws or other suitable fasteners (not shown). Base plate 6 includes a vertical portion 7 and a laterally extending end portion 8 arranged to support certain elements of the pencil sharpening mechanism of my invention, which will now be described.

Disk 5 is suitably secured to the end of shaft 3 by means of. a pair of cooperating nuts 9 and 10 threaded on the end of the shaft so that these parts rotate together. Disk 5 is provided with a flat abrasive surface on the side thereof facing motor 2. Preferably the abrasive surface of the disk is composed of tungsten carbide particles cemented in place, but it will be understood that any abrasive surface suitable for sharpening ordinary wooden pencils may be utilized. In order to support a pencil in contact with the abrasive face of disk 5, I provide guide means for supporting and guiding the pencil, including a guide bushing 11 having a mounting flange 12 secured to base plate portion 8 by a pair of screws 13. Guide bushing 11 includes a generally tubular portion 14 and a conical portion 15, and is arranged to support a pencil in a generally vertical position although it is inclined slightly so that the pencil is actually supported at a slight angle with respect to the plane of disk 5. As best shown in FIGLZ, a portion of guide bushing 11 is cut away on a vertical plane parallel to disk 5 so that a pencil supported in the bushing rests in contact with the abrasive surface of the disk. At the upper end of the guide bushing there is mounted an adjusting cap 16 which may be manually rotated with respect to the bushing and includes an offset pencil receiving opening 17; this cap is provided so that the angle between the longitudinal axis of the pencil and the plane of disk 5 may be adjusted with precision. It will be understood that this is a factory or service type adjustment which, once made, need not ordinarily be reset.

As shown in FIG. 3, guide bushing 11 is offset with respect to a vertical plane passing through the axis of rotation of disk 5. Further, the direction of this offset is toward the peripheral portion of disk 5 which moves downwardly during normal rotation, the direction of rotation being counter-clockwise as viewed in FIG. 3. Thus, in addition to the force of gravity which tends to feed a pencil being sharpened downwardly, a downward component of force is exerted on the pencil by the abrasive surface of disk 5. In this manner the pencil is continuously fed into the sharpening mechanism and need not be held or otherwise supported during sharpening operations.

Rotation of abrasive disk 5 also imparts a lateral component of force to the pencil tending to rotate it about its longitudinal axis, but it is desirable to provide a more positive means of assuring rotation of the pencil. Accordingly, I provide a resilient rotary member 18 positioned adjacent guide bushing 11 and arranged to contact the pencil and rotate it about its longitudinal axis. Rotary member 18 is secured to a vertical shaft 19 supported at its upper end by a bearing surface formed in base plate portion 8 and at its lower end in a bearing surface formed in bracket 21} secured to portion 7 of the base plate. Also secured to shaft 19 for rotation therewith is a worm wheel 21 arranged to mesh with a worm gear 22 carried by and co-axial with motor shaft 3. Thus, resilient rotary member 18 is positively rotated by motor 2 but at a considerably reduced speed by virtue of the speed reduction provided by gears 21 and 22. The direction of rotation of rotary member 18 is such that the force it applies to pencil is in the same direction as the rotary force component applied to the pencil by abrasive disk 5. In order to permit pencils to be easily inserted in the sharpening mechanism and to eliminate the need for close tolerances in positioning rotary member 18 with respect to guide bushing 14 and disk 5, I provide radially extending resilient fingers 23 on the periphery of the rotary member. During rotation of rotary member 18 fingers 23 pass through an opening 24 in guide bushing 11 and in doing so apply a force to the barrel of the pencil tending to rotate it about its own axis as previously described. The gaps between adjacent fingers 23 are such that a pencil may be easily inserted into sharpening position, and if it should happen that one of the fingers is in the position shown in FIG. 4 before the pencil is inserted, the

obstructing finger will be moved out of the way immediately upon energization of motor 2.

In order to collect the wood and pencil lead particles removed during sharpening operations, I provide a removable receptacle 25 releasably secured below the sharpening mechanism. Receptacle 25 is shaped so that it may slide upwardly within the end portion of easing 1 between its end wall 26 and vertical portion '7 of the base plate 5 and is secured therein by a spring catch 27 arranged to cooperate with projection 28 on the base plate. It will of course be understood that the sharpener which has been described is provided with an electric power cord (not shown) connected in circuit with motor 2 and that a suitable electric switch (not shown) is connected in the motor circuit. A sliding switch control 29 may be provided for actuating the switch between oil and on positions.

In operation, it will be understood that the improved sharpening mechanism of my invention functions to support and automatically feed a pencil during sharpening operations, and that once the pencil is inserted in guide bushing 14 nothing further need be done by the operator until the pencil has been sharpened and is ready for removal from the sharpener.

While I have illustrated and described a specific embodiment of my invention, I do not desire the invention to be limited to the particular construction disclosed and I intend by the appended claims to cover all modifications within the true spirit and scope of my invention.

What I claim is:

l. A pencil sharpener comprising a disk mounted for rotation on a horizontal axis, said disk having a flat abrasive surface on one side thereof, motor means for rotating said disk, and guide means for supporting a pencil of conventional size in contact with said abrasive surface, said guide means being offset from a vertical plane passing through the axis of rotation of said disk on the side of said plane where movement of the portion of said disk contacting said pencil is downward, said guide means including a generally tubular portion positioned so as to support said pencil with its longitudinal axis in a generally vertical position but slightly inclined with respect to the plane of said disk, the diameter of said tubu lar portion being greater than the diameter of said pencil so that the pencil is freely movable therein and the force of gravity and the movement of said disk cooperate with each other to position the pencil in contact with said disk and the rate of sharpening is controlled automatically as a function of the force of gravity and the rotational forces imparted by said disk.

2. A pencil sharpener comprising a disk mounted for rotation on a horizontal axis, said disk having a fiat abrasive surface on one side thereof, motor means for rotating said disk, guide means for supporting a pencil of conventional size in contact with said abrasive surface, said guide means being offset from a vertical plane passing through the axis of rotation of said disk on the side of said plane where movement of the portion of said disk contacting said pencil is downward, said guide means including a generally tubular portion positioned so as to support said pencil with its longitudinal axis in a generally vertical position but slightly inclined with respect to the plane of said disk, the diameter of said tubular portion being greater than the diameter of said pencil so that the pencil is freely rotatable therein, and a resilient rotary member adjacent said guide means arranged to contact said pencil and rotate it about its longitudinal axis, and means connecting said motor means in driving relation with said rotary member.

3. A pencil sharpener comprising a disk mounted for rotation on a horizontal axis, said disk having a flat abrasive surface on one side thereof, motor means for rotating said disk, guide means for supporting a pencil of conventional size in contact with said abrasive surface, said guide means being offset from a vertical plane passing through the axis of rotation of said disk on the side of said plane where movement of the portion of said disk contacting said pencil is downward, said guide means including a generally tubular portion positioned so as to support said pencil with its longitudinal axis in a generally vertical position but slightly inclined with respect to the plane of said disk, the diameter of said tubular portion being greater than the diameter of said pencil so that the pencil is freely rotatable therein, a rotary member having a plurality of radially extending resilient fingers adjacent said guide means, said guide means having an opening therein through which said fingers extend so as to engage said pencil during rotation thereof and rotate t .e pencil about its longitudinal axis, and means connecting said motor means in driving relation with said rotary member.

References Cited in the file of this patent UNITED STATES PATENTS 715,849 Oliver Dec. 16, 1902 995,764 Bertram June 20, 1911 2,614,534 Rocks Oct. 21, 1952

Claims (1)

1. A PENCIL SHARPENER COMPRISING A DISK MOUNTED FOR ROTATION ON A HORIZONTAL AXIS, SAID DISK HAVING A FLAT ABRASIVE SURFACE ON ONE SIDE THEREOF, MOTOR MEANS FOR ROTATING SAID DISK, AND GUIDE MEANS FOR SUPPORTING A PENCIL OF CONVENTIONAL SIZE IN CONTACT WITH SAID ABRASIVE SURFACE, SAID GUIDE MEANS BEING OFFSET FROM A VERTICAL PLANE PASSING THROUGH THE AXIS OF ROTATION OF SAID DISK ON THE SIDE OF SAID PLANE WHERE MOVEMENT OF THE PORTION OF SAID DISK CONTACTING SAID PENCIL IS DOWNWARD, SAID GUIDE MEANS INCLUDING A GENERALLY TUBULAR PORTION POSITIONED SO AS TO SUPPORT SAID PENCIL WITH ITS LONGITUDINAL AXIS IN A

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