WO1998018400A1

WO1998018400A1 - A training javelin

Info

Publication number: WO1998018400A1
Application number: PCT/US1997/020295
Authority: WO
Inventors: Thomas Alan Petranoff
Original assignee: Thomas Alan Petranoff
Priority date: 1996-10-31
Filing date: 1997-10-31
Publication date: 1998-05-07
Also published as: JP2000510025A; AU5172198A

Abstract

The invention provides a training javelin structure. The javelin structure has a nose component (12), a shaft component (11) and a tail component (10). Mechanical interlocking formations (19, 25), such as a spigot-socket arrangement, are provided on the components for interconnecting the components. The components are made of a resilient synthetic plastic material.

Description

A TRAINING JAVELIN

This invention lies in the field of javelins, that is javelins which are used in sporting events and relates in particular to a training javelin useful in the training of javelin throwing, particularly in regard to juvenile trainees

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 registration

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 of the Olvmpic specification javelin must be done under tightK controlled safetv conditions as the descending javelin is lethal to human beings as has been testified bv 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 mav 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 a a 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 first K 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 relatively hard form, the javelin mav 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 mav have mechanical interlocking formations to permit interconnection of the nose and shaft components and the shaft and tail components

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

Ijsuallv the mechanical interlocking formations are in the form of a screw threaded male portion matingfv engaging a complementary female portion

The components mav be connectable together bv the application of a bonding agent The nose component of the training javelin structure mav 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

^ς The hollow space included in the nose component improves the elastomeπc compressibility of the nose thereby 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

10 The tail component may include a generally elongate bodv and fins which are arranged spirallv along at least a part of the length of the bodv to induce rotational movement of the javelin structure in flight Typically the spiral angle is in the range of 1 ° to 1 ° Preferably the spiral angle is 3°

l ^ς The fins mav be removably attachable to the bodv Typicallv the generally elongate bodv is provided with grooves for receiving complementarv formations on the fins

The fins mav be bonded to the body bv means of a suitable bonding agent such as a contact adhesive or plastic cement Likewise the fins mav be welded to the bodv 0

The training javelin structure mav include at least one whistle on any component wherebv a whistling sound is produced bv the flight of the javelin

The shaft component may have a hand grip formation The shaft component mav ^ include a light source for example a globe The light source mav be solar pow ered or it mav be powered bv means of batteries included in the shaft component of the javelin The light source and batteries are preferably accommodated in a substantial 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 0

The shaft component may include a translucent (or transparent) area through which the light source may be viewed The weight balance of the assembled training javelin preferably is selected by attention to the relative weights of the component parts which have been described.

The training javelin structure components may be of a suitable synthetics 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 individually 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 polymer 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

Fi ure 8 is an elevation of one of the three tail fins. In Figure 1 the tail component 10 is connected to the shaft component 1 1 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 3° 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 1 1 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 narrow er size near the nose The nose 12 has a hollow space 23 in it which tapers to a narrow er 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 show s one of the three fins 13. 14 and 1 5 The fins include whistles located therein A prong 26 and a catch 27 anchor the fin in the groove 16. in each case

Claims

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

A training javelin structure as claimed in claim 1 in which the components have mechanical interlocking formations to permit interconnection of the nose and shaft components and the shaft and tail components

A training javelin structure as claimed in claim 2 in which the mechanical interlocking formations are in the form of a spigot and socket arrangement

Λ training javelin structure as claimed in claim 2 or claim 3 in which the mechanical interlocking formations are in the form of a screw threaded male portion matinglv engaging a complementarv female portion

A training javelin as claimed in anv one of the preceding claims in which the components are connectable together bv the application of a bonding agent

A training javelin structure as claimed in any one of the preceding claims in which the nose component has a hollow space within the nose component

Λ training javelin structure as claimed in claim 6 in which the hollow space is of conical shape tapering towards a free end of the nose component

A. training javelin structure as claimed in any one of the preceding claims in which the tail component includes a generally elongate body and fins which are arranged spirallv along at least a part of the length of the bodv to induce rotational movement of the javelin structure in flight A training javelin structure as claimed in claim 8 in which the spiral angle is in the range of 1° to 15°

A javelin structure as claimed in claim 9 in which the spiral angle is 3°

A training javelin structure as claimed in anv one of claims 8 to 10 in which the fins are removably attachable to the body

A training javelin structure as claimed in any one of claims 8 to 1 1 in which the generallv elongate bodv is provided with grooves for receiving complementary formations on the fins

A training javelin structure as claimed in anv one of claims 8 to 12 in which the fins are bonded bv means of a suitable bonding agent to the bodv

A training javelin structure as claimed in any one of claims 8 to 13 in which the fins are welded to the bodv

training javelin structure as claimed in anv one of the preceding claims including at least one whistle on anv component wherebv a whistling sound is produced bv the flight of the lavelin

Λ training javelin structure as claimed in anv one of the preceding claims in which the shaft component has a hand grip formation

A training javelin structure as claimed in anv one of the preceding claims, in which the shaft component includes a light source accommodated in a substantially shock-proof compartment in the shaft component

A training javelin structure as claimed in claim 17 in which the shaft component includes a translucent portion A training javelin structure as claimed in any one of the preceding claims, in which the components are of a suitable synthetics plastics material

A method of production of a training javelin as claimed in any one of the preceding claims, 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 as claimed in claim 20, including adding decorative and/or proprietary decals and/or logos subsequently or before assembly to the components

A training javelin structure, substantially as herein before described and illustrated

A method of production of a training javelin, substantially as herein before described