GB2085740A

GB2085740A - Darts

Info

Publication number: GB2085740A
Application number: GB8028639A
Authority: GB
Original assignee: DURRO FLIGHTS Ltd
Current assignee: DURRO FLIGHTS Ltd
Priority date: 1980-09-04
Filing date: 1980-09-04
Publication date: 1982-05-06

Abstract

A dart stem 1 has a readily scissile portion at its proximal end and can be attached to a dart barrel in its normal or any truncated condition obtained by cutting all or part of said portion from the stem. A flight can be attached to its distal end via slots 2. <IMAGE>

Description

SPECIFICATION Improvements in and relating to darts The present invention relates to the game of darts and provides a truncatable dart stem, a kit of parts including said stem for assembly into a dart, and a dart incorporating said stem in a normal or truncated condition.

In the game of darts, hand-thrown pointed mis siles, namely darts, are launched individually at a circular target, namely a dartboard, delineated cir cumferentially and radially into arcuate zones of assigned numerical value surrounding central inner and outer bullseyes, also of assigned numerical value. The darts are used in sets ofthree and each dart comprises a barrel which is gripped when throwing the dart and from which the point extends for penetrating the dartboard. A shaft or stem extends rearwardly (with respect to the point) of the barrel and carries, or is adapted to carry, a flight.

Often, the proximal end of the stem is externally threaded forthreadable engagement in a threaded bore in the barrel thereby permitting replacement of the stem.

The length of the stem affects the aerodynamics and balance of the dart. Thus, a player often requires to adjust the length of the stem to accommodate a personal preference orto improve the aerodyanmics and/or balance of the dart. In order to meet this requirement in darts having separable stems, a selection of stems or stem sections of predetermined different lengths can be provided (see, for example, U.K. Patent Specifications Nos. 1509198 and 1556806). However, this solution is not entirely satisfactory in that (a) increased costs are incurred in manufacturing the stems or stem sections of different lengths; (b) a player must purchase and transport a selection of stems or stem sections in order to be able to adjust the dart length when required; and (c) adjustment is only available in the increments by which the stem or stem section lengths differ.

It has been proposed, for example in U.K. Patent Specification No. 1556806, to provide a telescopic arrangement whereby small adjustments in the length of the dart can be made by varying the extent to which the proximal end of the stem extends into a bore in the barrel. In this connection, the term "barrel" is used in this specification to include a combination of the hand-gripping body of the dart together with any adaptor necessary to attach the stem to that body. Said telescopic arrangement can only accommodate small adjustments in the length of the dart and have been proposed as an addition to, and not substitute for, selection of a stem of appropriate length.

It is an object of the present invention to provide means for adjusting the length of a dart without having to resort to the manufacture of stems or stem sections of different lengths and/or the provision of a telescopic arrangement between the stem and bar rel. This object has been achieved by the use of a dart stem which is adapted to be truncated by cutting from a normal length to a desired truncated length.

According to a first aspect of the present invention, there is provided a dart stem having a readily scissile portion at its proximal end and carrying or adapted to carry a flight at its distal end, said stem also having attachment means extending uniformly over the length of said portion for attachment to a dart barrel, the arrangement being such that the dart stem is in its normal condition or in any truncated condition obtained by cutting all or part of said portion from the stem.

According to a second aspect of the present invention, there is provided a kit of parts for assembly into a dart, said kit comprising a dart barrel and a dart stem, the dart stem having a readily scissile portion at its proximal end and carrying or adapted to carry a flight at its distal end, said stem having attachment means extending uniformly over the length of said portion for attachment to the dart barrel, the arrangement being such that the dart stem can be attached to the said barrel with the stem in its normal condition or in any truncated condition obtained by cutting off all or part of said portion from the stem.

According to a third aspect of the present invention, there is provided a dart comprising a dart barrel having attached thereto a truncated dart stem, said stem having been obtained by cutting off all or part of a readily scissile portion at the proximal end of a longer dart stem adapted to be attached to said barrel in said longer condition.

The stem can be made of any suitable material but preferably is made of plastics, for example polycarbonate. The entire stem can be readily scissile or, more usually, onlythe required portion at its proximal end. Preferably, the flight is not formed integrally with the stem but the stem is provided at its distal end with means for receiving the flight. Suitably, said means for receiving the flight is constituted in known manner by a cruciform arrangement of longitudinally extending slots.

The attachment means by which the stem is attached to the barrel can be constituted by an external thread extending about the readily scissile portion or a threaded bore extending axially through said portion. In these cases, the barrel will have respectively an internally threaded bore or an externally threaded portion to cooperate with the stem.

However, it is preferred that the attachment means should be constituted by a non-threaded bore adapted to be a press-fit about a rearwardly extending pin protruding from the barrel. Particularly in the case of a blind bore, it is preferred that a plurality of axially extending ridges should protrude into the bore to facilitate gripping of the pin whilst permitting exhaust of air displaced by insertion of the pin into the bore.

The barrel can be formed as an integral element incorporating means cooperating with the attachment means of the stem. Alternatively, the barrel can comprise an adaptor for connecting the stem to a main body portion of the barrel. An adaptor will usually be required when a preferred stem having an unthreaded bore as described above is to be used in conjunction with a barrel body of conventional design. Such conventional barrel bodies usually have a threaded bore to receive the threaded end of a conventional stem and accordingly the adaptor will be provided with a threaded end to be received in said bore.

The following is a description, by way of example and with reference to the accompanying drawings, of preferred embodiments of the three aspects of the present invention. In the drawings: Figure 1 is a longitudinal section through a truncatable dart stem in accordance with a preferred embodiment of the present invention; Figure 2 is an end view of the stem of Figure 1 from the left-hand end of Figure 1; Figure 3 is a side view of an adaptor for use with thetruncatablestem of Figure 1; Figure 4 is a side view of the truncatable stem of Figure 1 mounted on the adaptor of Figure 3; Figure 5 is a side view showing the truncatable stem of Figure 1 with a dart barrel to which it is to be attached; and Figure 6 is a side view of an assembled dart including the barrel and stem of Figure 5.

Referring first to Figures 1 and 2, a truncatable stem generally indicated at 1 is formed of plastics, for example polycarbonate. The stem is formed with a cruciform arrangement of slots 2 at its distal end to receive flight 3 (see Figure 6). A blind bore 4 extends axially into the stem from its proximal end. Four circumferentially spaced and axially extending ridges 5 protrude into the bore 4. The proximal end of the stem has a planar outer rim 6 from which a frustoconical surface 7 converges to the bore 4.

The nature of the plastics material and the relative dimensions of the bore 4 in the stem 1 are selected so that the portion ofthe stem 1 along which the bore 4 extends is readily scissile. Thus, the stem 1 can be truncated by cutting off any desired length from its proximal end. If desired, axially spaced markings can be provided on the surface of the stem 1 to indicate predetermined distances from the rim 6.

In an alternative arrangement to that shown in Figure 1, a plurality of axially spaced circumferentially extending grooves can be provided in the stem 1 over the proximal end portion thereof to provide lines of weakness at which the stem can readily be cut.

The bore 4 and lugs 5 are uniform along the proximal end portion of the stem. Accordingly, a pin of predetermined diameter can be push-fitted into the bore 4 when the stem 1 is in its normal condition or any truncated condition.

The stem 1 can be connected to a conventional dart barrel having a threaded bore in the end thereof by means of an adaptor 8 (see Figure 3}. The adaptor comprises a frustoconical body portion 9 from which a pin 10 extends to be a push-fit in the bore 4. The adaptor 8 is provided at its forward end with a threaded portion 11 adapted to be received in the threaded bore of the dart barrel (not shovel.

Instead of using an adaptor 8, a barrel 12 (see Figure 5) can be provided which is formed integrally with a pin 1 0a for press-fitting in the bore 4.

The adaptor 8 conveniently is formed of metal, for example, aluminium. The barrel 12 can also be formed of metal, for example brass tungsten or nickel silver.

The length ofthe assembled dart (see Figure 6) can be truncated as required by cutting off an appropriate length from the proximal end of the stem 1 when the stem is separate from the barrel 12. The length of the dart can be predetermined by cutting the stem to length before assembling the dart. Alternatively, the dart can be assembled and subsequently the stem can be readily removed whilst a required portion is cut from it in order to truncate the length ofthe dart.

It will be appreciated that the invention is not restricted to the particular embodiments described above but that numerous modifications and variations can be made without departing from the scope of the invention.

Claims

1. A dart stem having a readily scissile portion at its proximal end and carrying or adapted to carry a flight at its distal end, said stem also having attachment means extending uniformly over the length of said portion for attachment to a dart barrel, the arrangement being such that the dart stem can be attached to the said barrel when the stem is in its normal condition or in any truncated condition obtained by cutting all or part of said portion from the stem.

2. A dart stem as claimed in Claim 1 which is made of plastics.

3. A dart stem as claimed in Claim 2 wherein the plastics is polycarbonate.

4. A dart stem as claimed in any one of the preceding Claims wherein the entire stem is readily scissile.

5. A dart stem as claimed in any one of claims 1 to 3 wherein only the said portion at the proximal end is scissile.

6. A dart stem as claimed in any one of the preceding Claims wherein the stem is provided at its distal end with means for receiving the flight.

7. A dart stem as claimed in claim 6 wherein said means for receiving the flight comprises a cruciform arrangement of longitudinally extending slots.

8. A dart stem as claimed in any one of the pre- ceding Claims wherein said attachment means is constituted by an external thread extending about the readily scissile portion.

9. a dart stem as claimed in any one of Claims 1 to 7 wherein said attachment means is constituted by a threaded bore extending axially through said portion.

10. A dart stem as claimed in any one of claims 1 to 7 wherein said attachment means is constituted by a non-threaded bore adapted to be a press-fit about a rearwardly extending pin protruding from the dart barrel.

11. A dart stem as claimed in Claim 10 wherein the said bore is blind and a plurality of axially extending ridges protrude into the bore to facilitate gripping of the pin whilst permitting exhaust of air displaced by insertion of the pin into the bore.

12. A dart stem as claimed in Claim 1 and substantially as hereinbefore described with reference to and as shown in Figures 1 and 2.

13. A kit of parts for assembly into a dart, said kit comprising a dart barrel and a dart stem, the dart stem being as claimed in any one of the preceding Claims.

14. A kit of parts as claimed in Claim 13 and substantially as hereinbefore described with reference toP and as shown in Figure 5.

15. A dart comprising a dart barrel having attached thereto a truncated dart stem, said stem having been obtained by cutting off all or part of a readily scissile portion at the proximal end of a longer dart stem adapted to be attached to said barrel in said longer condition.

16. A dart as claimed in Claim 15 wherein said longer dart stem is claimed in any one of Claims 1 to 12.

17. A dart as claimed in Claim 16 wherein the dart barrel is formed as an integral element incorporating means cooperating with the attachment means of the stem.

18. A dart as claimed in Claim 15 or Claim 16 wherein the dart barrel comprises an adaptor for connecting the stem to a main body portion of the barrel.

19. A dart as claimed in Claim 15 and substantially as hereinbefore described with reference to and as shown in Figure 6.