US2738768A - Pencil pointer - Google Patents

Description

March 20,1956 Y R. P. JOHNSON 2,738,768

PENCIL POINTER Filed Jan. 8, 1953 IN VEN TOR.

United States Patent PENCIL POINTER Robert P. Johnson, Monroeville, Ind. Application January 8, 1953, Serial No. 330,270

14 Claims. (Cl. 120-96) This invention relates to an improved pencil pointer. More specifically, it relates to a pencil pointer which is power driven and which is automatically started by the insertion of a pencil to form a perfect conical point on the pencil.

An object of the invention is to produce a pencil pointer which is simple and eflicient in its operation.

Another object of the invention is to provide an electrically driven pencil pointer which will be started by the insertion of a pencil.

Yet another object of the invention is to provide a pencil pointer which employs an abrasive member which is rotated to point the pencil.

Still a further object is to provide a pencil pointer which retains all of the material which is removed from the pencils and which is easily emptied.

A further object is to provide a novel magnetic means for holding the abrasive member in operative position. Still another object of the invention is to provide an abrasive member which is inexpensive and readily replaceable.

These and other objects will become apparent from a study of this specification, and the drawings which are attached hereto, made a part hereof and in which:

Figure 1 is a perspective view of the pencil pointer showing the pencil receiving opening and the cover.

Figure 2 is a sectional view taken on a vertical plane which includes the longitudinal axis of the pencil receiving opening.

Figure 3 is an elevation of the switch and switch actuator.

Figure 4 is a plan view of the magnet and disc driving nut.

Figure 5 is a side view of the mechanism of Figure 4.

Figure 6 is a plan view of the armature and abrasive member showing the driving nut in dashed lines.

Figure 7 is an edge view of the armature and abrasive member assembly.

Figure 8 is a modified form of member.

Referring now to Figure 1, the numeral 1 represents a case which is preferably of die cast metal. The case comprises a lower compartment 3 which houses the motor 5 and switch 7, and an upper compartment 9 which houses the abrasive mechanism and holds the material which is abraded.

A transparent cover 11 which is preferably of plastic material rests upon shoulders such as 13. A knob 15 is fixed to the cover to facilitate its removal and replacement.

The electric motor 5 is of small horsepower and relatively high speed and is mounted on the case by means of screws 19 and spacers 20. I prefer to use a ,4 H. P. motor operating at 2700 R. P. M. The shaft 21 of the motor projects through an opening 23 in the wall 25 which separates the two compartments.

The motor shaft has mounted on it, within the comarmature and abrasive partment 9, a shouldered mandrel 27 which has its small diameter threaded as at 29 to form a screw. A circular magnet 31 is pierced centrally to receive the screw and a hexagonal nut 33 mounted on the screw holds the magnet against the shoulder. The mandrel is held on the shaft 21 by a set screw 35.

An abrasive member, indicated by numeral 37, comprises a disc or armature of magnetic material such as thin sheet steel which has a D-shaped hole 39 formed at its central axis. This hole is so formed that it circumscribes the hexagonal nut 33 except on one side where it lies parallel to and in contact with a flat on the nut. In this way the nut drives the disc which is held against displacement axially of the shaft 29 by the magnet.

The disc may have cemented to it a disc 41 of emery or sand paper or cloth as shown in Figure 7 or it may have abrasive material 43 cemented directly to it as shown in Figure 8.

A cylindrical bore 45 is formed in the case. The longitudinal axis of the bore is directed so as to intersect the mutual axis of shaft 21 and screw 29, and at an angle of ninety degrees plus approximately half of the cone or apex angle of the point desired on the pencils to be sharpened by the disc, thus as a pencil is urged axially toward the disc, the portion of the pencil in contact with the abrasive will be removed and as the pencil is rotated 360 degrees about its axis, the end of the pencil will be pointed into a perfect cone. In other words, the longitudinal axis of the pencil intersects the plane of the abrasive disc at an angle which is substantially one half the desired apex angle of the conical point.

The switch 7 is mounted on the side of the case by bolts 47 and has the free end of its actuating lever 49 fitted with a yoke 51 provided with a pin 53 on which is rotatably mounted a concaved roller 55. The axis of the roller is disposed transversely of and below the axis of the bore 45. The roller 55 partially projects through a recess 57 which intersects the bore and obstructs the path of a pencil which enters the bore so that When a pencil is inserted, the roller will be pushed aside and its lever 49 will be depressed to close the switch 7 which is normally open.

The switch is connected to one terminal of the motor by wire 59 and to one wire 61 of the power cord 63. The other terminal of the motor is connected to the other wire 65 of the cord.

The case has a plug 67 fitted in a hole which enters the compartment 9 from the side approximately in line with the set screw 35 in one of its positions so that a tool can be inserted to actuate the screw.

The compartment 3 is closed by a bottom plate which is provided with pads 69 of rubber or other yieldable material at its corners. Screws 71 are provided to hold the plate in place.

- Operation The cord 63 which is provided with the usual plug 73 is connected with a receptacle. Whenever a pencil is inserted in the bore 4-5, it closes the switch 7 which starts the motor 5. The pencil is inserted further until it'contacts the now rotating disc. The pencil is now rotated through 360 degrees while in contact with the disc and the lead of the pencil is shaped into a cone.

As the pencil is withdrawn, it releases the roll 55 and the switch 7 opens to deenergize the motor.

To empty the receptacle 9, the cover 11 is merely removed and the device is inverted over a waste basket or other receptacle.

To replace the abrasive disc, the operator merely inserts a pencil point under a side of the disc, slips the point under the disc and into the center hole, which enables him to pull the disc off of the magnet without getting black lead on his fingers.

The disc projects beyond the periphery of the magnet as shown in Figure 2 to facilitate the removal and replacement of the disc.

It is obvious that various changes may be made in the form, structure and arrangement of parts without departing from the spirit of the invention. Accordingly, applicant does not desire to be limited to the specific embodiment disclosed herein primarily for purposes of illustration; but instead, he desires protection falling fairly within the scope of the appended claims.

What I claim to be new and desire to protect by Letters Patent of the United States is:

1. A pencil pointer comprising a permanent magnet, means for rotating said magnet about an axis, an armzn ture supported by the magnet and having an abrasive surface disposed normal to the axis of rotation, a pencil guide, means for supporting said guide adjacent said surface, said guide having a bore, the longitudinal axis of said bore being directed so as to intersect said surface.

2. A pencil pointer comprising a permanent magnet, means for rotating said magnet about an axis, an armature supported by the magnet and having an abrasive surface disposed normal to the axis of rotation, a pencil guide, means for supporting said guide adjacent said surface, said guide having a bore, the longitudinal axis of said bore being directed so as to intersect said surface at an angle to the surface which is substantially one half the desired apex angle of the point on the pencil.

3. A pencil pointer comprising a permanent magnet, means for rotating said magnet about an axis, an armature supported by the magnet and having an abrasive surface disposed normal to the axis of rotation, means releasably connecting said armature to be positively driven by said rotating means, a pencil guide, means for supporting said guide adjacent said surface, said guide having a bore, the longitudinal axis of said bore being directed so as to intersect said surface.

4. A pencil pointer comprising a permanent magnet, means for rotating said magnet about an axis, an armature supported by the magnet and having an abrasive surface disposed normal to the axis of rotation, a pencil guide, means for supporting said guide adjacent said surface, said guide having a bore, the longitudinal axis of said bore being directed so as to intersect said surface, said magnet rotating means comprising a motor, a switch connected to control the motor, a switch actuator including a roller disposed to extend into said guide means in the path of a pencil to be displaced thereby, said actuator when displaced serving to close said switch, said roller being supported on said actuator for rotation about an axis transverse to the axis of said guide.

5. A pencil pointer comprising a magnet, means for rotating said magnet about an axis including a motor having a shaft, a nut for holding the magnet on the shaft, an armature having an abrasive surface normal to the axis of rotation, said armature including means interfitting with said nut for the transmission of torque from the nut to the armature.

6. A pencil pointer comprising a magnet, means for rotating said magnet about an axis including a motor having a shaft, a nut for holding the magnet 011 the shaft, an armature having an abrasive surface normal to the axis of rotation, said armature comprising a disc, abrasive means fixed to the disc in a plane normal to the axis of rotation, said disc having a non-circular axial perforation for interfitting with the nut for transmission of torque from the nut to the disc.

7. The structure of claim 6 wherein the abrasive means comprises a sheet of material coated with abrasive ma terial of said sheet being fixed to the disc.

8. The structure of claim 6 wherein the abrasive means comprises abrasive material fixed directly to a surface or" the disc.

9. A pencil pointer comprising a case, means defining a first downwardly open chamber forming a base for the case and a second upwardly open chamber, said chambers being separated by a wall, a perforation in the wall, a motor mounted on the case in said first chamber and having a shaft extending through and substantially sealing said perforation, said shaft terminating in a driving clutch member, a magnet mounted on said shaft in said second chamber, abrasive means including an armature and a driven clutch member, said magnet serving to support said abrasive means and to hold said clutch members in driving engagement, and means for guiding a. pencil into intersecting relation with said abrasive means.

10. A pencil pointer comprising a case, means defining a first downwardly open chamber and a second upwardly open, refuse accumulating chamber, said chambers being separated by a wall, a perforation in the wall, a motor mounted on the case in said first chamber and having a shaft extending through and substantially sealing said perforation, said shaft terminating in a driving clutch member, a magnet mounted on said shaft in said second chamber, abrasive means including an armature and a driven clutch member, said magnet serving to support said abrasive means and to hold said clutch members in driving engagement, means for guiding a pencil into intersecting relation with said abrasive means, and a removable cover for said second chamber.

ll. A pencil pointer comprising a case, means defining a first downwardly open chamber and a second upwardly open chamber, said chambers being separated by a wall, a perforation in the wall, a motor mounted on the case in said first chamber and having a shaft extending through said perforation and substantially sealing said perforation, said shaft terminating in a driving clutch member, a magnet mounted on said shaft in said second chamber, abrasive means including an armature and a driven clutch member, said magnet serving to support said abrasive means and to hold said clutch members in driving engagement, means for guiding a pencil into intersecting relation with said abrasive means, a switch mounted in the first chamber for controlling the motor, and an actuator for said switch including means extending into said guide means for operation by a pencil inserted therein to close the switch.

12. A pencil pointer comprising a case, means for supporting a motor in said case, said motor having a shaft, a circular magnet mounted on said shaft, said magnet and shaft being coaxially arranged, a disc armature mounted on said magnet, abrasive means carried by the disc, axially engageable clutch means carried by said shaft and disc, said clutch means being held in en gagement by the attractive forces exerted by the magnet on said armature, and pencil guide means on said case for guiding a pencil in a path which intersects the path of the abrasive means.

13. A pencil pointer comprising a case, means for supporting a motor in said case, said motor having a Shaft, a circular magnet mounted on said shaft, said magnet and shaft being coaxially arranged, a disc armature mounted on said magnet, said disc having a greater diameter than said magnet to facilitate the separation of the disc and the magnet, abrasive means carried by the disc, axially engageable clutch means carried by said shaft and disc, said clutch means being held in engagement by the attractive forces exerted by the magnet o said armature, and pencil guide means on said case for guiding a pencil in a path which intersects the path of the abrasive means.

14. A pencil pointer comprising a case, means for supporting a motor in said case, said motor having a shaft, a circular magnet mounted on said shaft, said magnet and shaft being coaxially arranged, a disc armature mounted on said magnet, abrasive means carried by the disc, axially engageable clutch means carried by 5 6 said shaft and disc, said clutch means being held in en- References Cited in the file of this patent gagement by the attractive forces exerted by the mag- UNITED STATES PATENTS net on said armature, penci? guide means on said case for guiding a pencil in a path which intersects the path 1353966 lorenz a of the abrasive means, and means defining a receptacle 5 6182 ardner for said magnet and disc to receive and hold the material 16 stratford June 1937 removed by the abrasive means 2,243,490 Walker y 27, 1941 v 2,266,269 Romeiser Dec. 16, 1941 2,360,928 Beechlyn Oct. 24, 1944 10 2,662,353 Bergman et a1 Dec. 15, 1953

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