GB2052277A - Darts - Google Patents

Abstract

The attachment of flights to darts is by means of a flight holder connected to the shaft of the dart as a push fit with interposed 0 rings 18, 20. <IMAGE>

Description

SPECIFICATION Improvements relating to darts This invention relates to darts. One well known problem with darts is that a following dart may encounter the preceding one and cause damage.

Whilst this can be minimised, particularly by providing deflection surfaces, that is arranging so that the surfaces facing the rear of the dart are oblique rather than normal to the axis of the dart, complete avoidance of the problem is considered to the impossible. The object of the present invention is to provide a construction which enables the portions of the dart most likely to suffer damage to be replaced quickly and economically, without introducing penalties in reduced performance.

It is known, for example from Patents No. 516848 and 1516560 to provide a detachable shaft forming a flight holder, but this represents a substantial part of the complete dart, so that if the whole of the shaft and flight holder were to be replaced the expense would be proportionately large, bearing in mind that in sophisticated darts the shaft may be made of titanium or other relatively expensive material.

Moreover, in said Patent 1516560 the parts are "press fitted" together. Fitting by means of a press is necessary in order to ensure that the parts are satisfactorily secured together and that there is no risk of them becoming detached in ordinary use.

Hence, separation of the flight holder for replacement with another one is impossible for the ordinary player.

In accordance with the present invention a flight holder of a dart is connected to a shaft of the dart as an easy push fit of one relative to the other, and with an interposed "0" ring to provide a frictional resistance to separation of the two.

Preferably the flight holder is provided with a blind bore, and the shaft is provided with the 0 ring near its free end which is to engage in that bore, and then the flight holder (together with its flights) can be replaced quickly and economically. It will be noted that a minimum portion of the complete dart is replaced by these means, and in practice it is the flight and the flight holder which are the most vunerable to damage from a following dart.

The 0 ring will provide sufficient frictional resistance to relative movement of the shaft and flight holder to hold the two together in normal usage, but which resistance can be easily overcome by finger pressure.

If preferred two 0 rings can be used, spaced slightly apart along the length of the shaft, so as to ensure that the flight holder is maintained truly co-axial to the shaft; using a single 0 ring could in theory lead to the flight holder being tilted out of true on the shaft, at least to the extent possible to takeup all of the clearance between the shaft and bore per seat a single point. However Applicant has found that a single "0" ring is eminently satisfactory for most purposes.

The 0 ring or 0 rings may be engaged directly in grooves provided on the shaft, or if desired can be located on a thimble which is press fitted to the end of the shaft; the latter is preferred in cases where the shaft is made from a relatively exotic material such as titanium, in minimising the machining necessary to the shaft. Athimble may be machined for example from light alloy and press fitted to the end of the shaft, or possibly secured thereto with the aid of an adhesive.

The flight holder may be generally of the kind shown in Patent 1516560, that is to say being tapered forwardly and rearwardly from a mid point, and provided with a cruciform slot opening rearwardly to receive the flight vanes.

One presently preferred embodiment of the invention is now more particularly described with reference to the accompanying drawings wherein Figure l is an elevation of a complete dart; and Figure2 is an enlarged fragmentary and part sectional elevation of the same.

Referring to the drawings, the dart comprises a spike 10 which is secured to the leading end of a body 12, and a shaft 14 which is secured to the trailing end of the same, for example by being made unitary with a plug 16 which is screwe engaged in said body.

As best seen in Figure 2, the rear end of the shaft 14 is provided with a thimble 16 which is fixed to the end of the shaft and provides a pair of spaced annular grooves each of which receives a corresponding 0 ring 18 20.

Aflight holder 22 has an axial bore opening to its leading end so as to receive the thimble and 0 rings as a gentle push fit. The flight holder has a cruciform slot opening to its rear end, and this receives the actual flight 24.

1. Aflight holder of a dart connected to a shaft of the dart as an easy push fit of one relative to the other, with an interposed 0 ring to provide a frictional resistance to separation of the two.

2. Aflight holder as claimed in claim 1 wherein a pair of actually spaced 0 rings are provided.

3. A flight holder as claimed in claim 1 or claim 2 wherein the 0 ring or rings are provided on the shaft.

4. A flight holder as claimed in claim 3 wherein the 0 ring or rings are located on a thimble which is secured to the shaft.

5. A dart substantially as described with reference to the accompanying drawings.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements relating to darts This invention relates to darts. One well known problem with darts is that a following dart may encounter the preceding one and cause damage. Whilst this can be minimised, particularly by providing deflection surfaces, that is arranging so that the surfaces facing the rear of the dart are oblique rather than normal to the axis of the dart, complete avoidance of the problem is considered to the impossible. The object of the present invention is to provide a construction which enables the portions of the dart most likely to suffer damage to be replaced quickly and economically, without introducing penalties in reduced performance. It is known, for example from Patents No. 516848 and 1516560 to provide a detachable shaft forming a flight holder, but this represents a substantial part of the complete dart, so that if the whole of the shaft and flight holder were to be replaced the expense would be proportionately large, bearing in mind that in sophisticated darts the shaft may be made of titanium or other relatively expensive material. Moreover, in said Patent 1516560 the parts are "press fitted" together. Fitting by means of a press is necessary in order to ensure that the parts are satisfactorily secured together and that there is no risk of them becoming detached in ordinary use. Hence, separation of the flight holder for replacement with another one is impossible for the ordinary player. In accordance with the present invention a flight holder of a dart is connected to a shaft of the dart as an easy push fit of one relative to the other, and with an interposed "0" ring to provide a frictional resistance to separation of the two. Preferably the flight holder is provided with a blind bore, and the shaft is provided with the 0 ring near its free end which is to engage in that bore, and then the flight holder (together with its flights) can be replaced quickly and economically. It will be noted that a minimum portion of the complete dart is replaced by these means, and in practice it is the flight and the flight holder which are the most vunerable to damage from a following dart. The 0 ring will provide sufficient frictional resistance to relative movement of the shaft and flight holder to hold the two together in normal usage, but which resistance can be easily overcome by finger pressure. If preferred two 0 rings can be used, spaced slightly apart along the length of the shaft, so as to ensure that the flight holder is maintained truly co-axial to the shaft; using a single 0 ring could in theory lead to the flight holder being tilted out of true on the shaft, at least to the extent possible to takeup all of the clearance between the shaft and bore per seat a single point. However Applicant has found that a single "0" ring is eminently satisfactory for most purposes. The 0 ring or 0 rings may be engaged directly in grooves provided on the shaft, or if desired can be located on a thimble which is press fitted to the end of the shaft; the latter is preferred in cases where the shaft is made from a relatively exotic material such as titanium, in minimising the machining necessary to the shaft. Athimble may be machined for example from light alloy and press fitted to the end of the shaft, or possibly secured thereto with the aid of an adhesive. The flight holder may be generally of the kind shown in Patent 1516560, that is to say being tapered forwardly and rearwardly from a mid point, and provided with a cruciform slot opening rearwardly to receive the flight vanes. One presently preferred embodiment of the invention is now more particularly described with reference to the accompanying drawings wherein Figure l is an elevation of a complete dart; and Figure2 is an enlarged fragmentary and part sectional elevation of the same. Referring to the drawings, the dart comprises a spike 10 which is secured to the leading end of a body 12, and a shaft 14 which is secured to the trailing end of the same, for example by being made unitary with a plug 16 which is screwe engaged in said body. As best seen in Figure 2, the rear end of the shaft 14 is provided with a thimble 16 which is fixed to the end of the shaft and provides a pair of spaced annular grooves each of which receives a corresponding 0 ring 18 20. Aflight holder 22 has an axial bore opening to its leading end so as to receive the thimble and 0 rings as a gentle push fit. The flight holder has a cruciform slot opening to its rear end, and this receives the actual flight 24. CLAIMS

1. Aflight holder of a dart connected to a shaft of the dart as an easy push fit of one relative to the other, with an interposed 0 ring to provide a frictional resistance to separation of the two.

2. Aflight holder as claimed in claim 1 wherein a pair of actually spaced 0 rings are provided.

3. A flight holder as claimed in claim 1 or claim 2 wherein the 0 ring or rings are provided on the shaft.

4. A flight holder as claimed in claim 3 wherein the 0 ring or rings are located on a thimble which is secured to the shaft.

5. A dart substantially as described with reference to the accompanying drawings.