GB2195565A - Dart point sharpener and shaft roughener - Google Patents

Abstract

A body unit (a) has a central hole (b) for receiving the shaft (c) of a dart, initial insertion of the dart shaft causing its point to abut mid-way against an angled and resiliently mounted abrasive element (e) so that rotation of one relative to the other will abrade the point and gradually sharpen it. Continued rotation, whilst the shaft is further progressively inserted and gradually withdrawn, will cause the abrasive element, which is radially loaded by resilient means (f), to lift, pivot and pressurably adjust to the increasing diameter and changing contour of the shaft causing it to be totally abraded from the sharp point to the shaft's major diameter, thereby roughening the surface area which penetrates a dart board, improving its retention ability. <IMAGE>

Description

SPECIFICATION Dart point sharpener and shaft roughener The shafts of darts are processed with a high quality smooth surface which, whilst excellent for dart board penetration, is.not conducive of retention. Additionally, dart points frequently need to be sharpened.

This invention relates to a means for resharpening the point and also of roughening part of the length of the shaft in order to increase its ability to be retained, once thrown into a dart board.

In particular, it relates to a device which can be resiliently applied to the dart point and shaft by hand rotation of it or of the dart, ensuring even application of a roughened periferal surface from the point extending along the shaft for a distance equivalent to a dart's normal depth of penetration into a dart board.

TERMS OF REFERENCE Figure 1 DART-The parts of the dart referred to in this application are shown and identified.

Figures 2 and 3 ABRASIVE MEANSThe abrasive means may be any of the sections shown in Fig. 2 and may be made from: Solid abrasive materials or bonded abrasive particles.

* Metals or plastics material shapes faced with abrasive particles on the operating faces.

* Hardened steel shapes with file-like serrations, or saw-like teeth on the operating faces.

They may be used singly or applied in multiples as shown in Fig. 3.

Figure 4 RESILIENT MEANS-May be a metal or plastic spring clip, or a short length of rubber tubing Figure 5 ABRASIVE UNIT-When the abrasive means is assembled and retained by resilient means in a body unit.

I now describe a preferred design for achieving the sharpening and roughening process with reference to the drawings of the abrasive unit shown in Fig. 5.

The body unit (a) has a central hole (b) to freely receive the dart shaft (c), and a slot (d) to receive an abrasive means (e) retained by a circlip (f) fitted into a periferal retaining groove (g) which is so positioned as to allow the abrasive means to respond to the contour of the progressively inserted dart shaft whilst rotation is taking place. Views A, B and C show how the point then the shaft contour is abraded, sharpening the former and roughening the latter for a predetermined length controlled by the barrel abutting the end of the body unit. when the dart may be rotatably or directly withdrawn.

The abrasive means (e) referred to in this preferred design is of rectangular metal sec- tion with its operative face coated with abrasive particles.

HAND HELD OUTER CASE The abrasive unit is inserted into an outer case which may be provided in various forms including the purely functional and those that are longer than is functionally required to allow for descriptive shaping and decoration.

Three typical shapes are shown in Fig. 6 to all or some of which a clip or ring may be fitted to facilitate personal attachment.

Figure 7 ROTATABLE CASE-A case extended in the form of an arm (h) to allow an additional parallel hole which freely receives and rotates on a pivot pin (i) secured (j) into a wall-mounted plate (k) enabling the arm to be rotatably swung in a clockwise or anticlockwise direction by the hand held dart whilst the shaft is progressively inserted and removed.

1. A dart point sharpener and shaft roughener consisting primarily of an abrasive unit (Fig. 5) which houses a radially slidable abrasive means (Figs. 2 and 3) retained by inward pressure applied to it at a narrow mid-way point from the resilient means (Fig. 4) permitting some pivotability, and which is mounted in line with and angularly across and closing a central hole which containably receives the shaft of a dart, such that when this is partially inserted and contained, its sharp end makes contact mid-way along the inclined abrasive face (Fig. 5A) when rotation of one relative to the other in either direction will cause the point to be abraded and sharpened, and when the dart shaft is further inserted will cause the abrasive means to lift radially and pivot bringing its full length into potential abrasive use and enabling it to adjust to the increasing diameters and changing contour of the shaft, lying tangentially on all curved faces presented to it (Fig. 5B and C) where it swells from the sharp point to the major parallel diameter, so that if relative rotation continues whilst the shaft is progressively inserted and then gradually withdrawn, total abrasion of the shaft surface will be achieved and the shaft thereby roughened.

2. A dart point sharpener and shaft roughener as claimed in Claim 1 in which the abrasive means is a single abrasive block, abrasive faced block (Figs. 283) or either used with a packer.

3. A dart point sharpener and shaft roughener as claimed in Claim 1 in which the abrasive means comprises two or more abrasive pieces or abrasive faced pieces (Figs. 2 & 3).

4. A dart point sharpener and shaft roughener as claimed in Claims 1 and 2 or Claims 1 and 3 where the abrasive unit is contained in an outer casing of a decorative nature or descriptive form (Fig. 6 typifies).

5. A dart point sharpener and shaft rough

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Dart point sharpener and shaft roughener The shafts of darts are processed with a high quality smooth surface which, whilst excellent for dart board penetration, is.not conducive of retention. Additionally, dart points frequently need to be sharpened. This invention relates to a means for resharpening the point and also of roughening part of the length of the shaft in order to increase its ability to be retained, once thrown into a dart board. In particular, it relates to a device which can be resiliently applied to the dart point and shaft by hand rotation of it or of the dart, ensuring even application of a roughened periferal surface from the point extending along the shaft for a distance equivalent to a dart's normal depth of penetration into a dart board. TERMS OF REFERENCE Figure 1 DART-The parts of the dart referred to in this application are shown and identified. Figures 2 and 3 ABRASIVE MEANSThe abrasive means may be any of the sections shown in Fig. 2 and may be made from: Solid abrasive materials or bonded abrasive particles. * Metals or plastics material shapes faced with abrasive particles on the operating faces. * Hardened steel shapes with file-like serrations, or saw-like teeth on the operating faces. They may be used singly or applied in multiples as shown in Fig. 3. Figure 4 RESILIENT MEANS-May be a metal or plastic spring clip, or a short length of rubber tubing Figure 5 ABRASIVE UNIT-When the abrasive means is assembled and retained by resilient means in a body unit. I now describe a preferred design for achieving the sharpening and roughening process with reference to the drawings of the abrasive unit shown in Fig. 5. The body unit (a) has a central hole (b) to freely receive the dart shaft (c), and a slot (d) to receive an abrasive means (e) retained by a circlip (f) fitted into a periferal retaining groove (g) which is so positioned as to allow the abrasive means to respond to the contour of the progressively inserted dart shaft whilst rotation is taking place. Views A, B and C show how the point then the shaft contour is abraded, sharpening the former and roughening the latter for a predetermined length controlled by the barrel abutting the end of the body unit. when the dart may be rotatably or directly withdrawn. The abrasive means (e) referred to in this preferred design is of rectangular metal sec- tion with its operative face coated with abrasive particles. HAND HELD OUTER CASE The abrasive unit is inserted into an outer case which may be provided in various forms including the purely functional and those that are longer than is functionally required to allow for descriptive shaping and decoration. Three typical shapes are shown in Fig. 6 to all or some of which a clip or ring may be fitted to facilitate personal attachment. Figure 7 ROTATABLE CASE-A case extended in the form of an arm (h) to allow an additional parallel hole which freely receives and rotates on a pivot pin (i) secured (j) into a wall-mounted plate (k) enabling the arm to be rotatably swung in a clockwise or anticlockwise direction by the hand held dart whilst the shaft is progressively inserted and removed. CLAIMS

1. A dart point sharpener and shaft roughener consisting primarily of an abrasive unit (Fig. 5) which houses a radially slidable abrasive means (Figs. 2 and 3) retained by inward pressure applied to it at a narrow mid-way point from the resilient means (Fig. 4) permitting some pivotability, and which is mounted in line with and angularly across and closing a central hole which containably receives the shaft of a dart, such that when this is partially inserted and contained, its sharp end makes contact mid-way along the inclined abrasive face (Fig. 5A) when rotation of one relative to the other in either direction will cause the point to be abraded and sharpened, and when the dart shaft is further inserted will cause the abrasive means to lift radially and pivot bringing its full length into potential abrasive use and enabling it to adjust to the increasing diameters and changing contour of the shaft, lying tangentially on all curved faces presented to it (Fig. 5B and C) where it swells from the sharp point to the major parallel diameter, so that if relative rotation continues whilst the shaft is progressively inserted and then gradually withdrawn, total abrasion of the shaft surface will be achieved and the shaft thereby roughened.

2. A dart point sharpener and shaft roughener as claimed in Claim 1 in which the abrasive means is a single abrasive block, abrasive faced block (Figs. 283) or either used with a packer.

3. A dart point sharpener and shaft roughener as claimed in Claim 1 in which the abrasive means comprises two or more abrasive pieces or abrasive faced pieces (Figs. 2 & 3).

4. A dart point sharpener and shaft roughener as claimed in Claims 1 and 2 or Claims 1 and 3 where the abrasive unit is contained in an outer casing of a decorative nature or descriptive form (Fig. 6 typifies).

5. A dart point sharpener and shaft rough ener as claimed in Claims 1 and 2 or Claims 1 and 3 where the abrasive unit is contained in an outer casing specifically designed to be orbitally rotated by a hand held dart around a wall mounted spindle (Fig. 7 typifies).

6. A dart point sharpener and shaft roughener substantially as described herein with reference to Figs. 1-7 of the accompanying drawings.