Patent Application
20240060754
The present invention relates to a dart shaft.
Darts for use in the popular target sport typically comprise multiple individual components which are connectable together to form a complete assembled dart. A typical assembled dart comprises, in order from front to rear: a dart point (or tip), a dart barrel, a dart shaft, and a flight.
The dart shaft, which can also be referred to as a dart stem, can affect the speed, stability and angle of entry of the dart into the target dartboard.
Some dart shafts consist of one continuous portion. Other dart shafts comprise two separate portions which are connectable together. One particular known dart shaft of this type comprises a metal portion which connects to the dart barrel in an assembled dart, and a plastic portion which connects to the flight in the assembled dart. The plastic portion comprises an externally threaded projection at one end, which is engageable with an internally threaded bore of the metal portion. Thereby, the two shaft portions can be screwed together to form a complete dart shaft.
An advantage of the two-part shaft design is that a player can replace one of the two shaft portions without replacing the other. For instance, the overall dart shaft can be lengthened by exchanging a relatively short metal shaft portion with a longer metal shaft portion whilst using the same plastic portion, or different coloured portions could be swapped in. Therefore, the dart can be customised to the player's preferences without needing to replace the whole dart shaft.
However, when a dart comprising the two-part dart shaft described above falls onto a hard surface, e.g. due to a player dropping the dart or the dart bouncing off a dartboard onto a hard floor, then the plastic portion of the dart shaft is prone to snapping. The player must then replace the plastic portion, which is costly and inconvenient. Moreover, the externally threaded projection of the plastic portion may become lodged inside the metal portion when the plastic portion snaps, meaning the metal portion may also need to be replaced.
It is therefore desired to provide a dart shaft which is durable and does not need to be frequently replaced.
The present invention provides a dart shaft, comprising: a first shaft portion formed of metal, the first shaft portion having a first end for connection to a dart barrel and a second end comprising a first threaded portion; and a second shaft portion, the second shaft portion having a first end for connection to a flight and a second end comprising a second threaded portion; wherein the first threaded portion is externally threaded and the second threaded portion is internally threaded, and wherein the first and second threaded portions are configured to engage with each other to releasably connect the first shaft portion and the second shaft portion together.
The invention is based in part upon a recognition by the inventors that the known dart shaft described previously has a weak point at the base (or root) of the externally threaded part of the plastic shaft portion. This makes the shaft more likely to break upon impact with the floor due to the weakness of the plastic under the stresses endured. With the dart shaft of the present invention, since the externally threaded portion is formed of metal rather than plastic, the externally threaded portion is stronger and thus less likely to break. The invention therefore provides both the utility of a two-part dart shaft in relation to exchangeability of the individual shaft portions, whilst achieving strength and durability of the assembled dart shaft.
The first shaft portion may be formed of one or more different metals. Preferably the first shaft portion is formed of aluminium or an aluminium alloy. Aluminium and its alloys are relatively lightweight and strong, as well as low cost. Other example metals may include tungsten.
The material of the second shaft portion is not particularly limited. The second shaft portion may preferably comprise plastic, since plastic is lightweight and may provide balance in an assembled dart compared to the metal portion. The plastic may comprise nylon, polycarbonate or a carbon compound. The second shaft portion may alternatively comprise metal or another material. The second shaft portion may comprise a combination of two or more materials.
The first shaft portion and/or the second shaft portion may have an elongate shape. The elongate shape may have an external length to width ratio of at least 1.5 to 1, or at least 1.7 to 1, or at least 2 to 1. The external length may be an end-to-end length of the respective portion that is externally exposed when the dart is fully assembled.
The first shaft portion and/or the second shaft portion may have a substantially circular cross-section.
The first shaft portion may comprise a grip portion. The grip portion may be for allowing a player to better grip a dart comprising the dart shaft, relative to a smooth surface.
The grip portion may comprise a plurality of grooves or protrusions extending circumferentially around an external surface of the first shaft portion. The grooves or protrusions may extend along at least 50% of an external length of the first shaft portion, or along at least 60% or at least 70% of the external length of the first shaft portion. The grooves or protrusions may increase friction between the dart shaft and the player's fingers to thereby improve grip.
The first end of the first shaft portion may comprise a third threaded portion for engaging with a fourth threaded portion of a dart barrel. The third threaded portion may be an externally threaded portion for engaging with an internally threaded fourth threaded portion of the dart barrel. For example, the third threaded portion may have a 6 mm 2BA thread, which is a common thread used for dart barrels.
Alternatively, the third threaded portion may be an internally threaded portion for engaging with an externally threaded fourth threaded portion of the dart barrel. In some embodiments the first end of the first shaft portion may be configured to connect to the dart barrel via a different type of connection than a screw connection, such as snap-fit or friction fit, and the first end may be configured accordingly.
A typical flight comprises one or more fins, usually three or four fins, which have a flat shape. The first end of the second shaft portion may comprise one or more slits for receiving the fins of a flight. The one or more slits may extend from a tip of the second shaft portion along the second shaft portion in an axial direction. The axial direction may be the direction of the axis of the dart shaft. The number of slits preferably corresponds to the number of fins of the flight to be connected, e.g. if the flight comprises four fins then four slits may be provided. The slits may be arranged rotationally symmetrically around a central axis of the second shaft portion to improve balance of the assembled dart.
The dart shaft may comprise one or more washers. The dart shaft may comprise a first washer arranged around the second shaft portion for securing the flight thereto, for example by applying a compressive force to close the one or more slits. A second washer may be provided around the first shaft portion, so as to be located between the first shaft portion and the dart barrel in an assembled dart to provide cushioning between the components.
There may also be provided a dart comprising a dart point, a dart barrel, a dart shaft as described in accordance with the first aspect, and a dart flight; wherein the dart barrel is connected to the first end of the first shaft portion and the dart flight is connected to the first end of the second shaft portion.
Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which:
A dart shaft 1 according to an embodiment of the invention will be described with simultaneous reference to
The first shaft portion 2 is formed of metal, and specifically aluminium, and the second shaft portion 4 is formed of plastic, and specifically nylon.
A first end 6 of the first shaft portion 2 is for connection to a dart barrel 32 (shown in
A second end 10 of the first shaft portion 2 comprises a first threaded portion 12 which is externally threaded. The first threaded portion 12 is visible in
A second end 14 of the second shaft portion 4 comprises a second threaded portion 16 which is internally threaded. Again, the second threaded portion 16 is visible in
The second threaded portion 16 of the second shaft portion 4 is shown more clearly in
The first and second threaded portions 12, 16 are configured to cooperate to connect the first and second shaft portions 2, 4 together to form an assembled dart shaft 1 as shown in
Referring again to
The first end 8 of the second shaft portion 4 comprises four slits 20 (only one of which is visible in the Figures). The slits are for receiving the flight. The slits extend from a tip of the first end 8 of the second shaft portion 4 in an axial direction along the length of the dart shaft 1.
The first shaft portion 2 comprises a grip portion 24. The grip portion 24 comprises a plurality of radial grooves extending around an external surface of the first shaft portion 2.
The first shaft portion 2 comprises a washer 24 arranged thereon for location between the dart barrel (not shown) and the dart shaft 1 when the dart shaft 1 is connected to the dart barrel.
The second shaft portion 4 comprises a washer 26 arranged thereon for securing the flight to the dart shaft 1 when the dart shaft 1 is connected to the flight.
A complete assembled dart 28 is shown in
The dart point 30 is connected to a first end of the dart barrel 32.
The first end of the first shaft portion 2 is connected to a second end of the dart barrel 32. Specifically, the third threaded portion 18 of the first shaft portion 2 is engaged with an internally threaded bore of the dart barrel 32.
The flight 34 is connected to the first end of the second shaft portion 4.
