WO1997014476A1

WO1997014476A1 - Short range golf club, ball and course

Info

Publication number: WO1997014476A1
Application number: PCT/AU1996/000645
Authority: WO
Inventors: Warren Peter Hassall; Alan John Hassall
Original assignee: Club Golf Pty. Ltd.
Priority date: 1995-10-16
Filing date: 1996-10-11
Publication date: 1997-04-24
Also published as: AUPN597595A0

Abstract

A short range golf course (10), a large diameter low density golf ball (40) and a large head (50, 52) golf club (90) for use in playing a game of golf in a relatively small area. The golf course (10) has markers (25 to 28) which correspond in colour to the colour of the heads (50, 52) of the golf clubs (90) so that the golfer knows which golf club (90) to use even when the golfer does not recognise the shape and size of the golf clubs (90). The golf ball (40) and the golf club (90) are designed so that they have a feel, when used, which is similar to that of a conventional sized golf ball and golf club.

Description

TITLE

SHORT RANGE GOLF CLUB, BALL AND COURSE

FIELD OF THE INVENTION

The present invention relates to a short range golf club, ball and course particularly, although not exclusively, envisaged for use in the play of a short range golf game.

In the context of the present invention short range means that the length of each golf hole is less than about 240 metres, and more typically between 75 and 170 metres.

The purpose of the short range golf course of the present invention is to decrease the amount of land required for the play of a game of golf from 60 to 80 hectares (150 to 200 acres) down to 5 to 10 hectares (12 to 25 acres). That is to less than about 10% o the land required for a conventional range golf course

The purpose of the golf ball of the present invention is to have a shorter flight path than a conventional golf ball. This is achieved in part by using a larger lower density ball which has a higher wind resistance and a greater ability to absorb the impact of being struck by a golf club.

The purpose of the golf club of the present invention is to give the same feel as a conventional golf club whilst being able to be used with the larger golf ball so that the result is that the golf ball travels a maximum distance of about 100 metres, as compared to the maximum distance of about 240 metres for a conventional golf ball.

BACKGROUND OF THE INVENTION

GOLF COURSE

It is know to provide a long range golf course with compact arrangements of golf holes as typified by US4,928,973 (Perry et al), US5, 163,683 (Oswald). Both achieve this by using a single hole "golf park" with a designated area for teeing off for playing the "long" part of the game of golf, and a separate putting area for playing the "short" part of the game of golf. Separate balls are used in each part and there is no continuity between the long and the short parts of the game. Hence, a disadvantage of each of these golf parks is that the golfer looses the original "feel" of the game of golf because the golfer does not walk around a plurality of golf holes. Also, the number of golfers that can play a game of golf at any one time is limited to the width of the golf park and the number of golfers who can "tee off' at any one time. Further, there is an added problem with golfers loosing sight of their ball and confusing it with the ball of another player.

In US4,726,589 (Grigas) there is shown a compact golf course with a plurality of golf holes arranged in a grid. This allows for golf holes of conventional length to be used on a much smaller area of land. However, the apparatus of the golf game becomes much more complex since shelters and tunnels must be provided so that the golfers can walk between the golf holes and hit the golf ball without risk of being struck by a golf ball hit by another golfer This also takes away the feeling of openness and freedom which golfers experience on a conventional golf course

In US3, 427,030 (Ward) there is shown a miniature golf course having golf holes of about 20 metres in length Ward uses a hollow plastic golf ball for driving along the fairways of the golf holes and a solid golf ball for use in putting out on the golf greens. A disadvantage of Ward is that the feel of striking the golf ball along the fairways is lost because the golf ball is so light and offers very little resistance to the golfers stroke.

The golf course of the present invention allows golfers the freedom of walking about each of a plurality of golf holes as in conventional golf games. Also, play is conducted by separate groups of golfers on each golf hole independently of the other golf holes, except that play flows from one golf hole to the next hole as play is completed at each golf hole as in conventional golf games Hence, the original feel of the game of golf is substantially retained.

GOLF BALL

Golf balls for a short range golf game are typified by US3,427,030 (Ward), US4,776,596 (Noji a), AU77036/87 (Warrick et al), US3,515,389 (Wolfe), US4,676,508 (Dilny) and US4,026,561 (Baldorossi) Typically, these golf balls achieve short range flight by being much lighter than a conventional golf ball, or having a very large loss in momentum as they are struck by the golf club However, the feel of the golf ball is not the same as that of a conventional golf ball.

The golf ball of the present invention has a short range flight whilst having substantially the same "feel" as a conventional golf ball. That is, the response of the golf ball being struck by a golf club is substantially as a golfer would experience with a conventional golf ball - except that the range of travel is much less The feel is achieved by use of low density material to produce a larger dimension ball with a plurality of dimples to maintain grip in the air. GOLF CLUB

Golf clubs for short range games of golf are typified by US3,027,163 (Saatzer) and US4,026,561 (Baldorossi) both of whom discuss the use of large head golf clubs for use with oversized golf balls (larger than 100 mm diameter).

Saatzer suggests the use of a plastic head for the golf club and Baldorossi suggests that the head could be aluminium or any other material. We have discovered that in the search for the same feel as a conventional feel of golf club it is necessary to use a plastic head with a weight added to it to balance the head to the shaft ofthe golf club. We also discovered that a particular construction of head is required in order to withstand the impact forces which are experienced by the head at its connection to the shaft.

SUMMARY OF THE INVENTION

Therefore it is an object of the present invention to provide a short range golf course for use with a short range golf ball and golf club.

In accordance with one aspect of the present invention there is provided a short range golf course for use with a short range golf ball and a plurality of golf clubs of non-conventional shape and size, the short range golf course having a plurality of golf holes arranged adjacent to each other so that play can progress from one golf hole to the next in a continuous sequence, each golf hole comprising a teeing off area, a fairway, a golf green, and a plurality of markers, the markers being located along the length ofthe golf hole, each of the markers differing one from the other in a discernible way, and each of the markers providing an indication as to which one of the golf clubs is best used at that distance from the golf green so as to assist in deterrnining which one of the golf clubs to use at any position along the golf hole for striking the golf ball as close as possible to the golf green and so as to avoid confusion of the golfer in not recognising the shape or size of the golf clubs.

Typically, the markers are distinguishable, one from the other, by their colour.

Typically, the markers are the same colour as the heads of the golf clubs

In accordance with another aspect of the present invention there is provided a golf ball for use in playing a game of golf on a short range golf course with a golf club, the golf ball comprising: an outer skin which is relatively tough and in which is formed a plurality of dimples; and, an inner part which is made of relatively high impact absorbing material so as to reduce the transfer of momentum from the golf club to the golf ball so as to reduce the length of its flight; wherein the density ofthe golf ball is substantially less than that of a conventional golf ball so that a given amount of force applied from the golf club to the golf ball results in the ball having a shorter flight path than a conventional golf ball so as to suit the length of the golf holes ofthe short range golf course.

Typically, the golf ball is larger than a conventional golf ball and has a mass which is substantially the same as that of a conventional golf ball ie between 48 and 55 grams, or more particularly about 52 to 53 grams - so as to give a feel which is similar to that of a conventional size golf ball..

Typically, the relationship between the number of dimples, the diameter ofthe golf ball, the depth of the dimples and the average dimple spacing for the short range golf ball, in order to achieve the desired flight and feel characteristics, is given by the formula: d = kD * t' _ SV_ where k is a constant D is the external diameter ofthe ball t is the depth ofthe dimples

S is the average dimple spacing

Preferably, the distance between the dimples is substantially uniform so as to produce a relatively uniform turbulence around the golf ball. This uniformity is important because of the high drag to mass ratio ofthe golf ball.

In accordance with a further aspect of the present invention there is provided a golf club for use in playing a short range golf game with a large diameter, low density golf ball, the golf club comprising: a shaft; and, a head made of plastics material, the head having a solid hosel and a ferrule for attaching one end of the shaft to the hosel so as to increase the strength of the golf club at the connection between the head and the shaft so that the golf club can withstand the impact associated with striking the large diameter low density golf ball.

Typically, the head of the golf club has a recess for receiving a high density weight means (such as lead shot) for use in balancing the head to the shaft so as to give a conventional feel to the golf club.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the present invention will now be described with reference to the accompanying drawings in which :- Figure 1 is a plan view of a few golf holes of a short range golf course in accordance with the present invention;

Figure 2 is a side view of a golf ball in accordance with the present invention; Figures 3 and 4 are front and rear perspective views of a head of a driving golf club in accordance with the present invention;

Figure 5 is a lower perspective view of a head of a putter golf club in accordance with the present invention; Figures 6 and 7 are cross-sectional side views of a hosel for use with the heads of Figures 3 and 5 respectively; and,

Figure 8 is a side view of a golf club in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTtS. GOLF COURSE In Figure 1 there is shown a part of a short range golf course 10 with golf holes 20 numbered 12 to 16.

Each of the golf holes 20 has a fairway 22, a golf green 24 and a plurality of markers 25, 26, 27 and 28 located along the fairway 22. For convenience markers 25 to 28 have only been shown on golf hole number 14. The golf holes 20 range in length between 60 and 150 metres, and more particularly between 75 and 130 metres. Such lengths correspond to golf holes 20 having par values of between 3 and 5 strokes of a golf club as described hereinafter.

The markers 25 to 28 differ from each other in a discernible manner so that a golfer can identify how far down the fairway 22 he/she is. Typically, the markers 25 to 28 differ in colour. The colour of the markers 25 to 28 is set to match with the colours of heads of golf clubs used in the play of the golf game For example, the markers 25 could be coloured blue, the markers 26 coloured maroon, the markers 27 coloured green and the markers 28 coloured purple. These colours then correspond to colours ofthe heads ofthe golf clubs according to the distance which each of the golf clubs can be used to hit a golf ball. The golf club with a blue head (corresponding to the marker 25 which is the furthest from the golf green 24) being able to hit the ball the furthest distance and the golf club with a purple head (corresponding to the marker 28 which is situated at the golf green 24) being able to hit the ball the shortest distance (for use in putting).

Hence, an inexperienced golfer can identify which golf club to use by the correspondence between the colours ofthe heads ofthe golf clubs and the coloured markers 25 to 28 along the fairways 22. This is important in the context of the present invention because the heads of the golf clubs are much larger than those used in conventional games of golf. So to avoid possible confusion the colour correspondence is required.

The golf holes 20 follow on one to the next in a manner as used in conventional golf courses. That is golf hole 1 to 2 to 3 and so on up to 18 or 36 In the exemplary embodiment golf holes 20 numbered 12 to 16 are shown with walk ways between consecutive golf holes 20.

GOLF BALL In Figure 2 there is shown a golf ball 40 in accordance with the present invention. The golf ball 40 is made from a skin forming polyurethane which is capable of having dimples 42 formed in it. Typically, the golf ball 40 is made using a ratio of 100 40 of I413H polyurethane and VM30 isocyanite with a 3% cross-linker. Also, typically a fluorescent pigment is added as 1.5% by weight. The process of making the golf ball 40 is preferably conducted at 50 °C and left to set for about 5 minutes Once the golf ball 40 is removed from its mould its hard outer layer is pierced so as to release any excess gases which form during the curing process

The result is a golf ball 40 which has a tough outer layer 42 and a resilient inner part The outer Iayer 42 has a plurality of dimples 44 formed in it The "feel" of the golf ball 40 when struck by a golf club (described hereinafter) is intended to be substantially the same as that of a conventional golf ball For this purpose the golf ball 40 has a mass of between 48 and 56 grams, more particularly 52 or 53 grams. However, the diameter ofthe golf ball 40 is about 62 mm so as to provide a much greater resistance in the air and hence to travel shorter distances and so that the golf ball 40 has a much lower density than a conventional golf ball. Typically, the golf ball 40 travels up to about 70 metres maximum distance. Due to the resilience ofthe inner part ofthe golf ball 40 a substantial amount ofthe force ofthe golf club is absorbed by the golf ball 40 without resulting in increased distance of travel of the golf ball 40.

We have determined that in order to achieve the above mentioned characteristics in the golf ball 40 the relationship between the number of dimples, the diameter of the golf ball, the depth of the dimples and the average dimple spacing for the short range golf ball is given by the formula: d = _L___VΛ

where k is a constant

D is the external diameter ofthe ball t is the depth ofthe dimples S is the average dimple spacing In one form the golf ball 40 has a diameter of about 62 mm and carries 62 dimples 44 which are concave and have a diameter of about 8 mm and a depth of about 0.5 mm.

Preferably, the distance between the dimples 44 is substantially uniform so as to produce a relatively uniform turbulence around the golf ball. This uniformity is important because of the high drag to mass ratio ofthe golf ball 40 It is envisage that the mass, the diameter, the material and the dimple pattern and size of the golf ball 40 could be varied. However, by use of the above formula the relationship between these can be kept such that the resultant golf ball has substantially the same feel as a conventional golf ball although with larger size and significantly shorter travel.

GOLF CLUB In Figures 3 and 4 there is shown a head 50 for a golf club The head 50 corresponds to that of a so cailed "iron" for use in hitting the golf ball 40 intermediate distances In Figure 5 there is shown a head 52 for another golf club The head 52 corresponds to that of a so called "putter" And a further head (not shown) is used having the shape of a so called "driver" or "wood" The head 50 and 52 are similar and like numerals denote like parts. The heads 50 and 52 (and that of the wood) are larger than those of conventional golf clubs so as to be able to strike the larger than normal golf ball 40 The heads 50 and 52 are sized so that there is a similar correspondence in size between the heads 50 and 52 and the golf ball 40 as exists between golf balls and golf clubs of conventional size. The heads 50 and 52 are typically made from plastics materials Typically, a polycarbonate is used because of its strength and high impact withstanding ability For example, biophenol A polycarbonate CAS No 25971-63-5 (CAS = Chemical Abstracts Service specification) could be used for the heads 50 and 52 The polycarbonate is manufactured from Biophenol A and diphenyl carbonate or from Biophenol A and phosgene (carbonyl chloride)

Due to the very large size of the plastics material used the process of moulding the heads 50 and 52 must be very carefully controller. We have found that this can be achieved by drying the compounded polycarbonate material for 10 hours at 120 oC prior to injection moulding. Once the material has been injected into the mould it is allowed to cure for about 90 seconds.

Overcoming the difficulties of moulding such a large amount of plastic was also assisted by making cavities 60 in the heads 50 and 52.

The cavities 60 of the head 50 are filled partly or in total with lead shot or the like held in place with a epoxy glue such as Araldite. The lead shot increase the mass of the head 50 and gives is a feel which is similar to that of a conventional golf iron club. The head 50 has mounting holes 62 for receiving a striker plate 64 for covering the cavities 60 The striker plate has legs 66 for insertion into the mounting holes 62 for fixing the striker plate 64 to the head 50 The striker plate 64 can be made of harder material than the rest ofthe head 50 so as to increase the operational life ofthe golf club The heads 50 and 52 each have a hosel 72 and a base 74 The hosel 72 is preferably solid so as to increase the strength of the heads 50 and 52 at their attachment to the rest of the golf club

The cavity 60 of the head 52 is designed to receive a single large weight 76 and does not require a striker plate The weight 76 is held in place wit a sealing strip 78 which closes off the cavity 60 The weight 76 has the effect of giving the head 52 the feel of a conventional golf putter club

The head 50 is attached to the shaft of the golf club with a ferrule 70 (see Figure 6) located over the hosel 72 And the head 52 is attached to the shaft of the golf club with a ferrule 70A (see Figure 7) In order to maintain the strength of the attachment ofthe heads 50 and 52 to the shaft the hosels 72 must be solid Hence holes can not be formed in them to receive the shaft of the golf club Hence it is essential to use the ferrules 70 and 70A to attach the heads 50 and 52 to the shaft. Prior art golf clubs do not have nor require such ferrules since holes can be formed in their hosels and the shaft inserted into the hosel without the risk of the hosel breaking when the golf ball is struck with the golf club The ferrule 70 has an inner bevel 80 for accommodating the hosel 72 of the head 50, whereas the ferrule 70 A has an outer bevel 82 for accommodating the hosel 72 ofthe head 52 The difference between the two head 50 and 52 is that the hosel 72 of the head 50 flares out slightly after its initial cylindrical part and more clearance around the ferrule 70A is desired for the head 52 so as to provide more viewing area for sighting the golf ball when putting

Typically, the hosel 72 of the head 50 has a diameter of about 20 5 mm and the ferrule 70 has a length of about 50 mm and an external diameter of about 24 Typically, the hosel 72 of the head 52 has a diameter of about 19 8 mm and the ferrule 70 A has a length of about 50 mm and an external diameter of about 23 mm In Figure 8 there is shown a golf club 90 comprising a shaft 92, a hand grip 94, one of the heads 50 and 52 and a corresponding one of the hosels 70 and 70A. By the nature of the size weight and density of the head 50, 52 the golf club 90 has a feel which is substantially the same as a conventional golf club It is envisaged that in the play of a game of golf on the golf course 10, a set ofthe golf clubs 90 be used. The set of golf clubs 90 comprising a driver for striking the golf ball 40 a relatively long distance (up to about 70 metres), one or two irons for striking the golf ball 40 shorter distances, and a putter for use on the golf greens 24

IN USE

In use, a golfer selects a golf club whose head 50, 52 matches the colour of the marker 25 to 28 corresponding to his/her location along the fairway 22. The golfer then strikes the golf ball 40 with the head 50 of the golf club 90. Due to the mass and the balance of the golf club 90 and the mass and size and construction of the of the golf ball 40, the striking of the golf ball 40 has substantially the same feel as that of a conventional golf ball and club but the ball travels a much shorter distance

The golfer then chooses another golf club 90 to strike the golf ball 40 again from its landing place again according to correspondence with the coloured markers 25 to 28

The golf course 10, the golf ball 40 and the golf club 90 of the present invention have the advantage that they allow a game of golf which feels and behaves like a conventional long range game of golf to be played on a short range course Hence, the area required for the golf course 10 is greatly reduced Also, the amount of walking is reduced The feel of a conventional long range golf game is achieved by the mass, size, density and balance of the golf club 90 and the size, mass and density ofthe golf ball 40

Modifications and variations such as would be apparent to a skill addressee are considered within the scope of the present invention. For example, other forms of plastics materials could be used for the heads 50 and 52 provided that they are strong enough to withstand the impact of striking the golf ball 40 (and/or the ground - in a miss-hit) Also, other plastics materials could be used for the golf ball 40 provided that it is able to carry the dimples and absorb much ofthe impact of being struck by the golf club 90 so as to travel a relatively short distance The markers 25 to 28 could carry other indicia to indicate the correspondence between the markers 25 to 28 and the appropriate golf club 90 to use at that distance from the golf green 24 For example, the markers 25 to 28 could carry numbers or symbols and the golf clubs 90 carry corresponding numbers or symbols

Claims

CLAHMSThe Claims defining the invention are as follows:

1. A short range golf course for use with a short range golf ball and a plurality of golf clubs of non-conventional shape and size, the short range golf course having a plurality of golf holes arranged adjacent to each other so that play can progress from one golf hole to the next in a continuous sequence, each golf hole comprising a teeing off area, a fairway, a golf green, and a plurality of markers, the markers being located along the length of the golf hole, each of the markers differing one from the other in a discernible way, and each ofthe markers providing an indication as to which one of the golf clubs is best used at that distance from the golf green so as to assist in determining which one of the golf clubs to use at any position along the golf hole for striking the golf ball as close as possible to the golf green and so as to avoid confusion ofthe golfer in not recognising the shape or size of the golf clubs.

2. A short range golf course according to Claim 1, in which the markers differ in their colour and the golf clubs have heads which are coloured to correspond to the colours of the markers so as to indicate the golf club which is best suited for use at a particular distance along the golf hole and from the golf green.

3. A short range golf course according to Claim 1, in which the markers carrying differing symbols and the golf clubs have corresponding symbols so as to indicate the golf club which is best suited for use at a particular distance along the golf hole form the golf green.

4. A golf ball for use in playing a game of golf on a short range golf course with a golf club, the golf ball comprising: an outer skin which is relatively tough and in which is formed a plurality of dimples; and, an inner part which is made of relatively high impact absorbing material so as to reduce the transfer of momentum from the golf club to the golf ball so as to reduce the length of its flight; wherein the density ofthe golf ball is substantially less than that of a conventional golf ball so that a given amount of force applied from the golf club to the golf ball results in the ball having a shorter flight path than a conventional golf ball so as to suit the length of the golf holes of the short range golf course and so that when the golf club strikes the golf ball the golfer experiences a feel which is similar to that of striking a conventional small long range golf ball..

5. A golf ball according to Claim 4, in which the relationship between the number of dimples, the diameter of the golf ball, the depth of the dimples and the average dimple spacing for the short range golf ball is given by the formula. d = _D_____ SV_ where k is a constant D is the external diameter ofthe ball t is the depth ofthe dimples

S is the average dimple spacing

6 A golf ball according to Claim 5, having a diameter of about 62 mm, and having about 62 ofthe dimples, each ofthe dimples being concave and having a diameter of about 8 mm and a depth of about 0 5 mm

7 A golf ball according to Claim 5, having a mass of between 48 and 56 grams

8 A golf ball according to Claim 4, made using a ratio of 100 40 of I413H polyurethane and VM30 isocyanite with a 3% cross-linker.

9. A golf club for use in playing a short range golf game with a large diameter, low density golf ball, the golf club comprising. a shaft; and, a head made of plastics material, the head having a solid hosel and a ferrule for attaching one end of the shaft to the hosel so as to increase the strength of the golf club at the connection between the head and the shaft so that the golf club can withstand the impact associated with striking the large diameter low density golf ball

10. A golf club according to Claim 9, in which the hosel is solid and is devoid of a hole for receiving the shaft.

11 A golf club according to Claim 9, in which the head includes a cavity in which is located a weight means, the weight means being chosen to balance the golf club so that it has a feel similar to that of a conventional golf club used in long range golf