GB2205788A

GB2205788A - A pencil sharpener

Info

Publication number: GB2205788A
Application number: GB08714444A
Authority: GB
Inventors: Sven Wisting
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-06-19
Filing date: 1987-06-19
Publication date: 1988-12-21
Also published as: GB8714444D0

Abstract

A pencil sharpener includes a stored energy device into which mechanical energy is transferred manually, the energy either being released to a sharpening device at a given instant or when sufficient energy has been stored, or being transferred continuously to the sharpening device, thereby providing a comparatively smooth supply of energy to the sharpening device. In the embodiment shown, the stored energy device comprises an inertia motor (3) which incorporates a flywheel. Energy is imparted to the flywheel from a drive wheel (4) by rolling the wheel over a surface (6). The stored energy is then released via drive shaft (10) which rotates the sharpener (12). <IMAGE>

Description

PENCIL SHARPENERS This invention relates to pencil sharpeners.

It is difficult, when using a hand held pencil sharpener, to keep the relationship between the pencil and the sharpener steady and their relative rotation even, so that the pencil is sharpened smoothly.

The present invention provides an arrånger-nt that is easily operated and that provides even sharpening of a pencil.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a side view of a pencil sharpener.

Fig. 2 is a cross-section on the line II - II of Fig. 1 taken in the plane of the paper, Fig. 3 is a perspective view of the sharpener shown in Fig. 1, in use, Fig. 4 is a cross-section through a part of a modified pencil sharpener arranged in co-operation with a drive strip, Fig. 5 is a perspective view of the arrangement shown in Fig. 4, in use, and Fig. 6 is a diagrammatic cross-section through yet another embodiment.

Referring to the drawings, there is shown a casing 1 of a plastics material which has a thickened portion 2 supporting an inertia motor 3. A drive wheel 4, having an edge 5 which provides a high level of friction with a surface 6, has a portion which extends through an aperture 7 in the casing 1. The wheel 4 is coupled, via an axle 8 with a gear, indicated at 9, of a gear train of the inertia motor 3.

The inertia motor 3 is of a well know type in which energy, which is transmitted from the drive wheel 4 via a gear train, is stored in a flywheel and then released via a second gear train to an output shaft 10. The output shaft 10 is attached to one end 11 of a pencil sharpener 12 having a blade 13. At its other end 14, the pencil sharpener 12 is rotatably supported by a collar 15.

The collar 15 is itself supported by a curved arm 16 which extends from the casing 1. Inertia motors are commonly used for driving wheeled toys and since the inertia motor 3 may be of any known type its detailed construction is not described.

A cover 18, which is made of a clear plastics material, clips on to the casing 1, as shown at 19. A hole 21 is provided in the cover 18 in line with the end of the pencil sharpener 12 and a pencil, indicated at 22, is able to pass through the hole 21 into the sharpener 12.

The sharpener 12 is rotated by a user who holds the casing 1 in one hand and moves the arrangement over the surface 6 with the portion of the wheel 4 which extends through the aperture 7 in contact with the surface 6, so that the wheel 4 is rotated to cause energy to be stored in the flywheel in the inertia motor. It may be necessary to pass the wheel 4 over the surface 6 more than once in order to store the required amount of energy.

The energy may be released from the flywheel via the second gear train into the output shaft 10 either automatically when a given speed is reached, or by the shifting of the gear train by the user, who operates a button or lever (not shown) to engage the second gear train with the spinning flywheel. At this point, the sharpener is caused to rotate and the pencil 22 may be inserted through the hole 21 into the sharpener 12 and be sharpened.

Fig. 3 illustrates the action described above, with the casing 1 being held against rotation in the user's hand 24, and being moved in the direction of the arrow 25, the drive wheel 4 being rotated against the surface 6 in the direction of the arrow 26, and the pencil 22 being arranged for insertion in the direction of the arrow 27, via the hole 21 in the cover 18, into the sharpener 12.

In Figs. 4 and 5, there is shown a modified arrangement in which the drive wheel 4 has a toothed edge 29 which cooperates with a toothed rack 31 on a strip 32 which is placed on a table top 33 and is located on the table top 33 by a portion 34 of the strip 32 which extends around edge of the top 33.

The sharpener 12 is rotated, in the way described above, by rotating the wheel 4 in the direction of the arrow 26 upon the movement of the casing 1 in the direction of the arrow 25, as a result of the engagement of the toothed edge 29 of the wheel 4 with the toothed rack 31.

The use of the strip 32 protects the table top 32 against the marking which might otherwise occur, due to the action of the wheel 4 on the surface of the table top 32.

Referring to the embodiment shown in Fig. 6 in which similar parts to those previously described are given the same numerals, there is shown a diagrammatic illustration of a pencil sharpener including a casing 1 with, at one end, a detachable clear plastics cover 18. The cover 18, provides, as in the previous embodiments, a receptacle for shavings from the pencil sharpener 12. At the other end there is a cover 35, which is removable in order to obtain access two batteries, indicated at 36, a small electric booster motor 37 and a clutch 38. Extending through an aperture 7 in the casing 1, there is a drive wheel 4 which has a high friction edge 5 and is mounted on a shaft 39.Also mounted on the shaft 39 and rigid with the wheel 4 are a gear wheel 41, which forms the first gear in a train indicated at 42, and a gear wheel 43, which has teeth 44 which are accessible through the aperture 7.

The gear wheel 41 is coupled to a flywheel 45 via the gear train 42 which includes gear wheels 46 and 47 mounted on a shaft 48 and a gear wheel 49 which is mounted on a shaft 51. The shaft 51 also carries the flywheel 45 and extends to the clutch 38.

The gear wheel 43 is coupled to one end of the pencil sharpener 12 via a gear wheel 52, which is mounted upon a shaft 10. The pencil sharpener 12 is carried at its other end for rotation within a collar 15 in a similar way to the arrangements previously described.

The sharpener of Fig. 6 may be operated in a similar way to the arrangements previously described. Thus by pushing or drawing the arrangement over a surface in such a way that the drive wheel 4 is in contact with the surface and is rotated, the flywheel 45 is rotated via the gear train 42, and energy is stored in the flywheel 45. At the same time, the pencil sharpener 12 is rotated via the gear wheels 43 and 52 and, when the drive wheel 4 is no longer driven by being pushed or drawn over a surface, energy stored in the flywheel 45 is transferred via the gear train 42 and the gear wheels 43 and 52 from the flywheel 45 to the sharpener 12, in order to maintain the pencil sharpener 12 in smooth rotation.

Should additional energy be required to boost the rotation of the sharpener 12, the booster motor 37 may be coupled to the batteries 36, by means not shown, and be energised via the clutch 38 to drive the shaft 51 which carries the flywheel 45.

It will be understood, that, in the embodiment of Fig. 6, the flywheel 45 and the pencil sharpener 12 are directly and continuously coupled to the drive wheel 4.

In the embodiment of Fig. 6, there is provided an alternative means for manually driving the wheel 4 to that of engaging the wheel 4 on the surface of a table. The gear wheel 43 has flanges 54 and the teeth 44 of the gear wheel 43 may be engaged with teeth which stand up from a strip corresponding to strip 32 of Figs. 4 and 5 arranged on the surface of a table, in order to drive the wheel 4.

The flanges 54 guide the gear wheel 43 along the strip in this arrangement.

It is appreciated that, although the invention has been described, by way of example, with reference to particular embodiments, variations and modifications may be made.

For example, the casing may be other than egg-shaped, although the egg shape is particularly convenient for holding in the hand. Furthermore, a rotary movement may be imparted to the sharpener by means other than that shown. In one modification, the casing is not moved over a surface. A recoil mechanism, employing a cord which is pulled out of the casing is used in place of drive wheel 4 to cause the inertia motor and the sharpener 12 to rotate. Furthermore, the sharpener 12 need not be of the type employing a blade. The stored energy device or inertia motor may rotate a sharpener that operates by grinding, rather than cutting with a blade as in the embodiments described, or it may rotate a pair of rotatable helical cutters of well-known type.

It will also be understood that, in embodiments in which the sharpener is effective when rotated only in one direction, a ratchet and pawl mechanism may be incorporated in order to ensure that the sharpener may rotate only in the required direction.

Although in the embodiment described only one arm 16 is used to support the collar 15, it will be appreciated that more than one arm 16 may be used, or the sharpener 12 could be supported at one end only.

The transparent cover 18 enables the user to see when shavings from the pencil sharpener need to be emptied, and acts as a container for the shavings.

In use, the arrangements described are normally pushed along the co-operating surface in a direction away from the user. The strip 32, which clips over the edge of a table top, makes this method of operation particularly easy.

In any of the embodiments described a clutch may be employed in order to enable the drive to the sharpener 12 to be coupled and decoupled from the remainder of the drive mechanism, as required.

In the embodiment of Fig. 6 the gear trains and the flywheel are coupled to the sharpener 12 via a shaft 10 which passes through a seal in a wall in order to isolate the drive mechanism from the shavings. In the other embodiments the flywheel and gear train are in a sealed unit.

In yet another embodiment the store of energy is not provided by an inertia motor or flywheel, but by a coil spring which is wound-up my means of a key, the clockwork motor providing the source of stored energy which may be applied directly via a gear train to the sharpener 12 or via a flywheel.

It will also be understood that energy may be supplied to the stored energy device by means of a cord which is pulled by the user, not only as a part of a recoil mechanism, but directly, with the cord being wound around a pulley wheel by the user before it is pulled.

The sharpener described above employs energy, which is obtained and stored in one embodiment without the use of a separate source of power, such as mains or batteries.

It employs power provided by the user. It is, therefore, independent and cheap to operate and may be-used anywhere and provides a source of power which provides even torque.

Claims

1. A pencil sharpener including a stored energy motor device, means to transfer energy to and store energy in the device and means for transferring energy stored in the device to means for sharpening a pencil.

2. A pencil sharpener as claimed in claim 1 including a flywheel in the device for storing the energy.

3. A pencil sharpener as claimed in either claim 1 or claim 2 including a wheel arranged to be rotated in order to generate energy to be transferred to and stored in the means for storing energy.

4. A pencil sharpener as claimed in claim 1 in which the stored energy device is a clockwork motor.

5. A pencil sharpener as claimed in any one of the preceding claims including a gear train for transferring energy to the device.

6. A pencil sharpener as claimed in claim 4 or claim 5 in which the gear train for transferring energy to the device is also used to transfer energy from the stored energy motor device to the means for sharpening a pencil.

7. A pencil sharpener as claimed in any one of the preceding claims including a clutch in the means for transferring energy stored in the device to the means for sharpening a pencil.

8. A pencil sharpener substantially as described herein with reference to Figs. 1 to 3, Figs. 4 and 5 or Fig. 6 of the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS 1. A pencil sharpener including a stored energy motor device, means to transfer energy to and store energy in the device and means for transferring energy stored in the device to means for sharpening a pencil.

4. A pencil sharpener as claimed in any one of the preceding claims including a clockwork motor for storing energy.

5. A pencil sharpener as claimed in any one of claims 1 to 3 including a battery and an electric motor for storing and generating energy.

6. A pencil sharpener as claimed in any one of the preceding claims including a gear train for transferring energy to the device.

7. A pencil sharpener as claimed in claim 6 in which the gear train for transferring energy to the device is also used to transfer energy from the stored energy motor device to the means for sharpening a pencil.

8. A pencil sharpener as claimed in any one of the preceding claims including a clutch in the means for transferring energy stored in the device to the means for sharpening a pencil.

9. A pencil sharpener substantially as described herein with reference to Figs. 1 to 3, Figs. 4 and 5 or Fig. 6 of the accompanying drawings.