GB2244947A

GB2244947A - Cutting blades

Info

Publication number: GB2244947A
Application number: GB9013285A
Authority: GB
Inventors: Kwok Hung Leung
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-06-14
Filing date: 1990-06-14
Publication date: 1991-12-18
Also published as: JPH04189302A; GB9100636D0; GB2244916A; CN1057181A; GB9013285D0

Abstract

A set of cutting blades, particularly for use in a finger nail-cutting device, comprises an inner cylindrical tube 15 adapted to be rotated within an outer tube 16, which may also be cylindrical and a generally longitudinally extending slot 17, 18 in each tube. At least one edge of each slot is sharpened, the sharpened edges of the two slots cooperating upon rotation of the inner tube to sever material extending through the slots. The width W is 1-2 mms to allow entry of a nail but not of adjacent soft tissue; different sizes may be provided for different nail thicknesses. The tube 15 is rotatable by a motor (12, Fig 1) via gearing (13), in either direction if both edges of the slots are sharpened. to allow left- or right-handed use. In table-mounted form, only one edge of each slot is sharpened and the motor rotates in only one direction. A finger rest (20, Fig 1) and a fan to collect or expel clippings may be provided. <IMAGE>

Description

CUTTING BLADES This invention relates to cutting blades for use in a

cutting device particularly, though by no means exclusively, for human nails, and a cutting device incorporating such blades.

Conventional methods of nail cutting involve the use of nail scissors or nail clippers. Neither can be operated with equal ease ambidextrously. Both are difficult to operate, if at all, by a weak hand, as of an elderley person for example, produce a course finish requiring if desired subsequent use of a nail file and can cause damage to soft tissue adjacent the nail. A further disadvantage_is the often uncontrolled flight of clipped portions of nail which have to be gathered after the cutting operation.

It is an object of the present invention to provide cutting blades and a nail cutting device incorporating same which overcome, at least to some extent, the disadvantages aforesaid.

According to the present invention there is provided a set of cutting blades comprising an inner circular tube adapted to be rotated within an outer tube and generally axially extending slots in each of said tubes, at least one edge of each slot being sharpened, i i the sharpened edges of the two slots cooperating upon rotation of the inner tube to sever material extending through the slot in the outer tube.

The outer tube may also be circular.

Both edges of each slot may be sharpened.

The edges of the slot in the outer tube may be parallel with the longitudinal axis of the tube.

The edges of the slot in the inner tube may diverge outwardly from one another towards one end of the tube.

The slot in the outer tube is sized to permit entry of the edge of a human nail.

One or both of the slots may extend through an end of the wall of its tube.

A nail cutting device may comprise a set of cutting blades as aforesaid.

The device may have a handle to which the outer tube is secured and incorporating drive means for rotating the inner tube.

1 A finger rest may be connected with the handle to aid the introduction of a nail to be cut into the slot in the outer tube.

The drive means may comprise an electrically powered motor connected with the inner tube by gearing.

The inner tube may be drivable at sufficiently high speed that a sweeping arcuate movement of the edge of the nail through the slot in the outer tube results in such multiplicity of cuts as to give a smooth finish to the cut edge.

The drive means may additionally drive a fan to blow air or suck air in through the bore of the inner tube to collect or expel nail clippings therefrom.

Both edges of each slot may be sharpened and the motor drive may be reversible.

The invention will be further apparent from the following description, with reference to the several figures of the accompanying drawings, which show, by way of example only, one form of nail cutting device incorporating cutting blades embodying same.

Of the drawings:- Figure 1 shows a partially cut-away perspective view of the nail cutting device; Figure 2 shows an exploded perspective view of the principal parts of the nail cutting device of Figure 1; Figure 3 shows on an enlarged scale a side view of the outer tube of the set of blades of the device of Figure 1; and Figure 4 shows on an enlarged scale a side view of the inner tube of the set of blades of the device of Figure 1.

Referring now to Figures 1 and 2 it will be seen that the nail cutting device comprises a handle generally indicated at 10 which houses batteries 11, a DC motor 12 and a planetary reduction gearing system generally indicated at 13 as well as an on/off switch 14 for the motor 12 which can be operated to drive the motor in either direction.

The device includes a set of cutting blades comprising an inner circular tube 15 and an outer -R- circular tube 16. Both tubes are of steel. The inner tube 15 which has a sliding fit within the outer tube 16 can be rotated therein at a high speed by the motor 12 via the gearing system 13. The outer tube 16 is fixed relative to the handle 10.

From the open free ends of the inner and outer tubes 15 and 16 extend generally axially aligned slots 17 and 18 respectively part-way into the lengths of the tubes.

The edges of the slot 17 diverge outwardly from one another towards the free end of the tube 15, and both are sharpened.

The edges of the slot 18 are parallel with the longitudinal axis of the tube, and again both are sharpened.

The slot 18 in the outer tube 16 is sized to permit entry of the edge of a human nail but not any adjacent soft tissue. Typically its length L (see Figure 3) will be 11.5 mm and its width W between 1 mm and 2 mm, it being understood that different sizes may be provided and suited for different thicknesses of nail. The wall of the outer tube will have a typical thickness of 0.25 mm.

The slot 17 in the inner tube 15 lies within that portion of the tube 16 provided with the slot 18 and has a length of 14 mm and a width of 3.5 mm tapering to 0.8 mm.

In use the device is held in one hand, and the motor 12 operated in such direction that as the inner tube 15 is rotated the edges of the slot 17 move downwardly over the edges of the slot 18. Each nail on the other hand opposite that holding the device is introduced through the slot 18 in turn and swept therethrough with an arcuate movement. The inner tube rotates at sufficiently high speed to produce a sufficient multiplicity of adjacent cuts as to give a smooth finish to the trimmed edge.

A finger rest 20 is provided adjacent the cutting blades to facilitate the cutting operation.

It will be understood that no manual force is required to effect the cutting action, which is both painless and comfortable.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof as defined by the appended claims.

Thus. for example, the device need not be hand held. It could be table mounted, in which event the motor need drive the inner tube in one direction only and one edge only of each slot need be sharpened.

Again, for example, the motor may drive a fan to blow air or suck air in through the bore of the inner tube to collect or expel nail clippings therefrom, perhaps into a collection compartment.

Claims

1. A set of cutting blades comprising an inner circular tube adapted to be rotated within an outer tube and generally axially extending slots in each of said tubes. at least one edge of each slot being sharpened,the sharpened edges of the two slots cooperating upon rotation of the inner tube to sever material extending through the slot in the outer tube.

2. A set of cutting blades according to claim 1, wherein the outer tube is circular.

3. A set of cutting blades according to claim 1 or claim 2, wherein both edges of each slot are sharpened.

4. A set of cutting blades according to any of claims 1-3, wherein the edges of the slot in the outer tube are parallel with the longitudinal axis of the tube.

5. A set of cutting blades according to any of claims 1-4, wherein the edges of the slot in the inner tube diverges outwardly from one another towards one end of the tube.

6. A set of cutting blades according to any preceding claim, wherein one or both of the slots extends through an end of the wall of its tube.

7. A set of cutting blades according to any preceding claim, wherein the slot in the outer tube is sized to permit entry of the edge of a human nail but not any adjacent soft tissue.

8. A nail cutting device comprising a set of cutting blades according to claim 7.

9. A device according to claim 8 having a handle to which the outer tube is secured and incorporating drive means for rotating the inner tube.

10. A device according to claim 9, wherein the drive means comprises an electrically powered motor connected with the inner tube by gearing.

11. A device according to either claim 9 or claim 10, wherein the inner tube is drivable at sufficiently high speed that a sweeping arcuate movement of the edge of a nail through the slot in the outer tube results in such multiplicity of cuts as to give a smooth finish to the cut edge.

12. A device according to any one of claims 8-11 including a finger rest connected with the handle to aid the introduction of a nail to be cut into the slot in the outer tube.

1

13. A device according to any one of claims 9-12, wherein both edges of each slot are sharpened and the motor drive is reversible.

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14. A device according to any one of claims 9-13, wherein the drive means additionally drives a fan to blow air or suck air in through the bore of the inner tube to collect or expel nail clippings therefrom.

Published 1991 at The Patent Office. Concept House. Cardiff Road. Newport. Gwent NP9 I RH. Further copies may be obtained from Sales Branch. Unit 6. Nine Mile Point. Cwnifelinfach. Cross Keys, Newport. NP I 7HZ. Printed by Multiplex techniques lid. St Mary Cray. Kent.