A training javelin design has been published in the present inventor and applicant's registered RSA design No. 92/1056. Reference is made to the two sheets of drawings which are attached to that design rezistration.

The present invention relates to the structural design and to the methods of manufacture of training javelins of this general kind.

It is well recorded that the throwing ofthe Olvmpic specification javelin must be done under tightly controlled safetv conditions as the descending javelin is lethal to human beings as has been testified by media reports. This problem has been a factor contributing to a rather low level of introduction of javelin throwing training at schools. for example. This in turn militates against the development of the sport and its expansion world-wide.

These considerations led to the development of the training javelin of the general concept that may be gathered from the aforementioned design registration and since then a measure of acceptance of this concept of training javelin can be achieved.

The manufacturing techniques used in the manufacture of the javelin have resulted in restraints on production volumes. These techniques have included the use of low pressure injection moulding techniques and an integral construction which have, for example. been used up until now to mould the javelins.

The low pressure injection moulding technique results in a low rate of manufacture of javelins as well as there being a high rate of rejection of javelins so manufactured due to. inter alia. misalignment of the moulds. trapped air bubbles in the final product and so on.

Further to this. the chemical from which the javelins are manufactured in the low pressure moulding technique results in the javelins (and therefore. more importantly the nose components) being relativelv hard. This results in a two fold disadvantage in that firstly. the nose area of the javelin tends to degrade after the javelin has been thrown and impacted with the ground a few times. and secondly, in such a relativelv hard form.

the javelin may still hurt someone whom it collides with in full flight.

A need exists for a training javelin that is easier and cheaper to manufacture that does not include the abovementioned disadvantages.

Accordingly there is provided a training javelin structure which includes a nose component. a shaft component and a tail component which are connectable together to form the training javelin structure.

The components may have mechanical interlocking formations to permit interconnection of the nose and shaft components and the shaft and tail components.

Typically. the mechanical interlocking formations are in the form of a spigot and socket arrangement.

Usually the mechanical interlocking formations are in the form of a screw threaded male portion matingly engaging a complementanr female portion.

The components mav be connectable together bv the application of a bonding agent.

The nose component of the training javelin structure may have a hollow space within the nose component. Typically the hollow space is of conical shape tapering > towards a free end of the nose component.

The hollow space included in the nose component improves the elastomeric compressibilitv of the nose therebv resulting in both a safer training javelin and a longer lasting javelin with the nose now being more resistant to breakage on impact with the ground after having been thrown.

The tail component may include a generally elongate body and fins which are arranged spirallv along at least a part of the length of the body to induce rotational movement of the javelin structure in flight. Typicallv the spiral angle is in the range of 1" to 15" Preferablv the spiral angle is 3° The fins may be removablv attachable to the body Typically. the generally elongate body is provided with grooves for receiving complementary formations on the fins.

The fins may be bonded to the body by means of a suitable bonding agent. such as a contact adhesive or plastic cement. Likewise the fins may be welded to the body.

The training javelin structure may include at least one whistle on any component whereby a whistling sound is produced by the flight of the lavelin.

The shaft component may have a hand grip formation. The shaft component ma',' include a light source. for example a globe. The light source may be solar powered or it may be powered bv means of batteries included in the shaft component of the javelin.

The light source and batteries are preferablv accommodated in a substantially shock- proof compartment in the shaft component to prevent damage to the light source and/or batteries upon impact of the training javelin with the ground.

The shaft component may include a translucent (or transparent) area through which the light source may be viewed.

The weight balance of the assembied training javelin preferably is selected bv attention to the relative weights of the component parts which have been described.

The training javelin structure components may be of a suitable svnthetics plastics material.

The invention extends to a method of production of a training javelin as described above. including the steps of high speed high pressure injection moulding of each of the components and assembling the components by hand or robotic means.

The method may include adding decorative and/or proprietary decals and/or logos subsequently or before assembly to the components The javelin may be decorated with paint which may be applied before or during manufacture. i.e. before use. or the javelin may be individuallv decorated with paint by a user thereof In this respect the javelin may be supplied in kit form, the kit including the javelin (either in component form or pre-assembled) as well as paint and/or decals for individual decoration of the javelin by a user thereof Colour may also be included in the polvmer formulation used for moulding.

The invention will now be described with reference to the following non-limiting illustrations in which: Figure 1 is an isometric projection of the training javelin: Figure 2 is an elevation of the shaft component of the training javelin; Figure 3 is a cross-sectional elevation of the shaft component: Figure 4 is an elevation of the nose component of the training javelin: Figure 5 is a cross-sectional elevation of the nose component: Figure 6 is an elevation of the tail component: Figure 7 is a cross-sectional elevation of the tail component: and Figure 8 is an elevation of one of the three tail fins.

In Figure 1 the tail component 10 is connected to the shaft component 11 which is connected to the nose component 12. Three fins 13. 14 and 15 are locked in grooves 16 in the tail component Each fin has integrally at its base a strip 17 which is slid into the matching groove in the tail component. Although the grooves are aligned with the longitudinal centre line of the javelin the fins are inclined on the strips at 30 to the longitudinal centre line. This gives optimal rotation of the javelin during flight. As shown in Figures 2 and 3. the shaft component includes on one end. a neck 18 including a collar 19 for mechanical interlocking with a reciprocal formation 25 on the nose component (see Figure 5) of the training javelin. The shaft component 11 further includes on a second end thereof internal screw threads at 20 which can screw onto external screw threads at 21 on the tail component (see Figures 6 and 7). A hand grip 22 is provided on the shaft component. and the shaft tapers to a narrower size near the nose The nose 12 has a hollow space 23 in it which tapers to a narrower size near the end 24 The formation 25 which receives the formations 18. 19 on the shaft component are shown in Figures 2 3 and 5.

Figures 6 and 7 show the tail component 10 with external threads 21 and grooves 16 (one is seen) for the fins.

Figure 8 shows one of the three fins 13. 14 and 15. The fins include whistles located therein. A prong 26 and a catch 27 anchor the fin in the groove 16. in each case.