AU676750B2 - Sporting apparatus - Google Patents

Description

SPORTING APPARATUS This invention relates to a golf club putter.

This invention has a particular application to a golf club putter, as defined by the rules of golf.

The term "fairway" throughout this patent application shall refer to that part of the golf "course" other than the putting green.

A tremendous amount of 'fairway' club design is constantly being undertaken, W'ith the object of driving the ball longer distances and with greater directional control. By comparison, there does not seem to be very much scientific thought applied to the golf club putter, or, the engineering concepts are sadly lacking. There is a vast difference between the fairway club stroke and the putt stroke. One strives for distance and the other demands a short but exact distance. So far, a putter has been regarded and constructed as a 'one iron'. That is, a modified fairway club, which is most inappropriate for the putting green. The fairway stroke demands as much force as the player can produce. By contrast the putt stroke calls for a very delicate and well controlled movement.

A putter has only TWO facts to be considered in its design:-- 1. The line of travel (of the ball). The direction of momentum.

i: 2. An exact length of travel or distance (of the ball) MASS times VELOCITY FORCE.

Hence, just the right amount of force in the right direction is all that is required.

The invented putter addresses these, by introducing a substantially more flexible shaft together with a specially shaped head, the weight of which is related to the shafts flexibility.

Although it possesses extremely good, in fact exceptional feedback characteristics, the resonate feedback, is not what the object of the proposed invention is about, but could be claimed as an added benefit.

Feedback is what happens after the ball is struck (to late to do anything).

25 The purpose of the proposed invention is to give more or greater control over the putt stroke, before the ball is struck, It is believed that to "feel" the forces at work during a putt stroke, would give the player the information to judge the direction and intensity of the stroke which players are not receiving with existing putters, ""To clarify the OBJECT of my proposed invention, the foregoing, will describe the characteristics of the currently used golf club implements, which by contrast, relate to this application.

To consider the 'fairway clubs and how they perform during the stroke action, we could take what may be regarded as a 'rigid' shaft driver and during the swing observe a peripheral head speed of approx 100 mph. At this speed, the shaft of the driver can deflect in the vicinity of 50 mm during the stroke. No doubt a steel shaft will deflect less, and a graphite a bit more. High speed photography will show up the shafts deflection as well as the ball impact, where the ball can be observed being taken from zero velocity to somewhere near 100mph, all in the fraction of a second.

mmi 2 During this time, the ball remains in contact with the club face and is subject to some considerable stress. Sometimes sufficient stress, to disintegrate the ball.

Engineering science would say a rigid shaft attached to a solid head having as much mass as a golfer could swing would produce the greatest force to propel the ball the greatest distance.

But that only takes into account the golfer and the club. To take the ball into account, its design is determined by rule parameters, the result being, it can only take so much force.

Therefore, fairway clubs have to include in their design, a shock absorbing component, to absorb the shock, at the point of impact, and assist the ball overcome its inertia of zero to accelerated speeds in the fraction of a second.

This is why cast iron driver heads are NOT used, and wooden or more modem plastic composition heads are used with varying degrees of success, as they soften the impact, but maintain the speed. Another way of softening the impact is to incorporate some flexibility into the shaft. This has the effect of allowing the head to momentarily stop when it comes in contact with the ball and at the same time allow the upper part of the shaft maintain its 100 mph velocity. As the ball overcomes inertia and accelerates, we may now become aware of the shafts flexible design, the art of which is to have the head end of the shaft catch up with the grip or "butt" end speed, by the time the ball leaves the head. Now it should be quite obvious that too much flexibility will result in the i ball not keeping up with the upper butt end speed of the shaft and at the opposite end of the scale a too rigid shaft will result in excess stress upon the ball which will dissipate the force intended.

20 Shaft design must also take into account the oval or sometimes wide face of the club head which could result in the ball being struck off the 'toe', centre or 'heel' of the club face. Played off the toe or heel results in a tumrning moment in the shaft. (referred to in the game as 'torque')This then becomes another factor in the design of a fairway club, or more specifically, the shaft.

For optimum performance, fairway shaft design today has to include S: 25 1) a small controlled amount of deflection, to deflect at a certain point, or along an area of the 2) shaft, 2) and be able to resist a tuming moment.

t A tremendous amount of design is constantly being undertaken, resulting in no doubt many S o patents being submitted, pertaining to 'fairway' club design. All have the object of driving the ball longer distances with improved directional control.

An example of shaft design, such a patent would be:-- Fundamental Golf Co application No:- 41729 93 Date:- 02 07 93 These patents are about the structure, arrangement and type of fibres used to produce a point of flexibility or a type of flexibility in the shaft. But above all else, all existing patents are directed towards achieving the greatest possible distance after striking the ball. That is:- they are designed for'fairway' play. All the shafts of these clubs, are regarded as rigid.

3 We know that most materials flex (stress), some to a minute degree others to a very obvious degree. Golf club players regard their clubs to have rigid shafts, i.e. if they are held horizontally, they appear to be rigid, even when swung from side to side they still appear to be rigid.

They may "whip" when wung vigorously, but any flexibility detected would be small enough to be disregarded.

All putters made today will tolerate a 100 mph peripheral sw'ng and strike a golf ball to drive it in the same manner as a fairway 'iron' or club. A gimmick often performed by 'pro' golfers for the amusement of the crowed. Which tends to prove a point, that all putters used today are modified fairway clubs. The shafts are the same, and the heads are modified.

The proposed invented putter has been designed exclusively for the requirements of the putt stroke, on the putting green. The shaft of this putter will n.ot tolerate the momentum, generated by a 100mph peripheral swing or anyth; g like it. The reason for this being is, that it has a very flexible shaft.

Although shaft flexibility has been considered in other previous fairway club designs, the amount is very much smaller, and for different reasons, than what I have incorporated in the S: proposed invented putter. None seem to have set any parameters. Because of the very low 0 peripheral speed used in a putt stroke, a fairway type shaft used in a putter can only be regarded as rigid, even in the longest of putts. That is, without the 100 mph momentum, or in a static state they 20 are rigid. They would be better described as deflecting under the force, and that would be a substantial force, of momentum and impact, rather than flexible, i By contrast the amount of flexibility in the invented putter is so great that if held horizontally, gravity acting upon the head, will show a noticeable deflection of about 38 mm.

By contrast the amount of flexibility in the invented putter is such that a relatively short putt :0 o0 25 stroke will deflect the putter shaft, if moved too quickly, (say 5 to 10 mph) By contrast the amount of flexibility in the invented putter is such that any attempt to use it as a l'tee' off or fairway club would break the shaft, or more likely flex to the extent of striking the player at the end of the stroke.

The concept of introducing a very flexible shaft to the mechanics of putting, between the S 30 head and the grip, results in;-- The shaft isolates all other mass beyond the head, leaving only the mass of the putter head.

The shaft indicates the swing alignment or direction of momentum of the head.

The shaft responds by flexing to the mechanics of the stroke action.

It encourages a pendulum like swing being the preferred movement of the putt stroke.

Its this flexing response that provides the player with the "feel" to the stroke.

It would be logical to assume that to reduce the variables in the 'force' formula, to constants would be desirable for performance enhancement, or assist player concentration. If 'force' is what moves the ball the desired distance, then all that has to be considered is the mass and velocity components.

To consider the 'mass' of the putt stroke, the head has to be a fixed 'constant', (governed by the rules of golf). However, should a rigid shaft putter be used, then a degree of mass from the shaft and the arms of the player must also be included. The amount of arm mass being determined by the degree of firmness to which the player grips the shaft.

By adopting the stroke swing, of pivoting the shoulders about the spine, will have the effect of including the arms in the mass. Hence the mass is very much a variable and depending upon the firmness of grip and whether the stroke action is pivoted from the shoulders or the wrists, or a combination of, then the total mass becomes a very difficult amount to be determined.

The invented putters very flexible shaft will isolate all other mass from or beyond the head mass. This makes the head mass constant. There could be a small amount of mass from the flexible shaft, but at the same time it would be insignificant and still constant.

It might be better said that the flexible shaft allows only the head mass to effect the mass x velocity formula. By "allows" we mean, if the player keeps the shaft straight during the stroke then they know that no other forces are operating, just the head weight.

20 If the mass is constant, then all that is left is the velocity. This can be controlled by "letting the headweight do the work". The rule being;a short backswing for a short putt, and a long backswing for a long putt. (Refer; figure 6.) Hence, by determining the distance of the putt (length of ball travel) and relating it to the backswing distance will determine the velocity. Velocity is hard to determine, backswing distance is much easier. By using a flexible shaft and keeping it straight, the backswing ,istance will be directly related to the velocity. i.e. only gravity acting upon the head mass. This makes the velocity much easier to determine as the backswing distance and shaft are visible.

*In effect, the player applies force through the grip to initiate the backswing stroke. At the top of the backswing, the player applies no further force but allows the headweight and a pendulum action to do the work. Should the player inadvertently apply force either positively or negatively,push or hold back) then the shaft is sufficiently flexible to visibly show a deflection. Thus the player now has the facility to observe a straight shaft and know that only the headweight is doing the work.(FIG 6).

The same rules of pendulum action and relating backswing distance could be applied to the rigid shaft putters, but the player has no idea of their inadvertently applying extra force or holding TR back on "letting the headwork do the work". The flexible shaft shows this up.

3A4,

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The proposed flexible shaft enables the player to distinguish between the necessary movements to correctly execute a putt stroke, and the unnecessary movements that would detract from a correct stroke. If the player keeps the shaft straight, then the necessary movements to hole the ball will occur. If the shaft deflects, then unnecessary movements are taking place, most likely resulting in not holing the ball.

We therefore have visible information before the ball is struck and a tactile response after.

Unlike the Driver or fairway 'power' stroke, the putt stroke exerts a barely perceptible amount of force, in particular a short putt is so small it is difficult to detect.

A trial backswing with the invented flexible shaft putter will give the player a much more realistic "feel" of the headweight, as the response can be seen and felt. All movements with the flexible shaft putter will visibly show gravity acting upon the mass of the head.

The head bounces around as though it is hanging off a strip of rubber, the effect gives the player the 'feel' of weight, which allows much better judgement of how much of this weight, to apply to the ball, especially for the short putts.

This very flexible shaft will show up putt stroke swing errors. The club head can be swung up :i and down a line on the ground at a speed which allows the shaft to flex. The object of this is to S match the line on the head with a line on the ground. The flexing shaft will immediately respond to S the players swing or stroke movements, and display the direction of momentum. This could be in the form of the head moving in a figure 8 patten, or the line on the head could turn or run off the line on the ground, the flexing shaft tends to exaggerate the players stroke action.

S° Its this flexing which enables the player to correct and perfect their swing or stroke alignment. The invented putter responding to the players stroke action.

o The amount of flexibility can be one of choice but the choice is best within a range, which 25 must be related to the headweight. To determine the flexibility, a blank shaft is fixed in a horizontal position at the grip or butt end. It is restrained on top at the butt end and restrained underneath S 250mm from the butt end (grip length). with the 'tip' (head end) at zero, a 500 gram weight is suspended from the tip, being 800 mm from the butt end, and the deflection recorded.

C.

The most suitable range would be between a 30 mm deflection to a 150 mm deflection measured in a vertical plane.

To address the mechanics of putting, the design rule would be:a heavy head attached to a low deflection shaft a light head attached to a high deflection shaft Trials soon determine the most suitable combination between these parameters.

I

The flexible shaft, having made the head mass constant and gravity acting upon the head mass being constant, enables a backswing distance to control the velocity. These constants are maintained by keeping the shaft straight. This must give the player far more control of the putt stroke than with a rigid shaft. The player now has a fixed mass and a controlled velocity, which should result in a far more consistent putt stroke.

One object of the very flexible shaft, is to encourage players to adopt the well recognised pendulum like swing for the putt stroke. When using the flex shaft putter, a player endeavours to keep the shaft straight, and by doing so, i.e. not letting it flex, a pendulum like swing is achieved.

In addition to a pendulum like swing, the only mass striking the ball is the headweight, the highly flexible shaft isolates any other form of mass, such as the shaft or arms of the player.

In addition to the flexible shaft, the head has been designed to provide an even amount of mass behind the face together with a centre rear projection. As the putt stroke is a very small, short and gentle stroke, there does not seem to be any reason for the putter "face" to be any bigger than the ball. However the preferred size would be 35 mm high x 60 mm wide, with a loft angle chosen from a vertical line, between 0 to 3 degrees, sloping from the bottom edge of the face, to the top edge toward the rear, which should be ample.

A wider face is to be avoided so as to prevent the ball being played off the furthest point of i the face, from the player, (the "toe") or the closest point of the face, to the player, (the "heel"). A ball played off the extreme ends of the toe or heel of the putter face, will create turning moments.

20 Resisting these turning moments is a problem in shaft design. There is no physical advantage in purposely playing off the toe or heel of a putter. Some golfers believe that there is. For consistent play the ball is best played off the centre face at all times. If a ball is played off the toe or heel, the player will 'feel' the turning moment in the grip. When using the current rigid shaft putter with a long face, the only way a player can get any 'feel' is to play off the toe or heel. Playing off toe, centre or 25 heel does not seem to encourage consistent play.

However the invented putter, having a flexible shaft gives the player far more feel for the pq ,t S° headweight control. Thus to play off the centre at all times will achieve more consistent control.

A ball played off the toe or the heel will generate a turning moment in the shaft, which is not desirable. However, a club head, having a face width of 60 mm or less, and a rear projection of 0 a 30 sufficient mass, will help resist the inertia of the turning moment, created by the ball striking the toe or heel of the putter face, thus maintaining the direction and momentum of the club head. It is evident, that unlike the fairway strokes, where the ball stays with the face of tl., club head for a very short time, the putt stroke results in the ball leaving the club head face instantly, being of a low velocity impact.

Therefore should the ball be piayed off the toe or heel of this particular desi' putter head, by the time a turning moment takes effect and alters the club head face direction, the ball will have left and thus its line of travel will not be affected.

As the club head face is relatively narrow compared to putter heads in use today, trying to square off the face to the line could be more difficult and an added mental process. A line has been added to the top surface of the putter head, starting from the top centre of the face, extending to the rear extension and square to the face. This line can be matched to the line of ball travel on the ground.

The head would be better regarded as a "suspended" head, the flexible shaft acting more like a string lie' holding the head, rather than a head fixed to a rigid shaft. Therefore, the mass of the club head should be greater than the mass of the ball, sufficient to not noticeably affect the inertia of the club heads momentum, when striking the ball.

Head weights between 300 grams and 450 grams seem to satisfy this requirement.

Whichever weight is chosen, the weight of this head has to be related to the shafts flexibility.

Trials and preference determine the amount of flexibility of the shaft which is in turn affected .i by the weight of the head. One such sample would be a 400 gram head attached to a shaft that has a deflection of 45 mm, (when tested by the 500 gram weight as previously described).

To demonstrate the accuracy of the pendulum action using the invented putter, having the function of the flexible shaft combined with the headweight and shape, that it is adequate and S 20 superior to the rigid shaft, can be demonstrated by the use of a mechanical testing device.(FIG 6) The p:oposed putter head can be suspended (without the shaft) by two strings from each side of the head. The suspending strings being angled outward in a slight V' shape) from the head, to be attached at the top to a horizontal fixed bar, approximately 1200 mm above the arass.

The bar height is adjusted so that the head will just clear the grass (or carpet) when swung, 25 the whole arrangement being set up to represent the stroke action of a player.(see FIG 6) The head is steadied and a golf ball is placed in front of it. The head can then be drawn backwards to a fixed point then released. The head will hit the ball and make the ball travel (2 or 3 metres) to a point on the ground.

This operation can be repeated as many times as you like and providing the ball is placed in the same position each time and the head drawn back to the same position each time then the ball will travel the same distance to the same spot each time The back swing distance can also be tested by moving the fixed point closer to the ball (a short backswing) to give a shorter distance of ball travel. By moving the fixed point further away from the ball a long backswing), to give a longer distance of ball travel. Refer FIG 6.

II 8 When tested on the string pendulum, the proposed head design will allow the ball to be struck off the toe or the heel of the face, without affecting the alignment. This observation confirms that the ball leaves the head instantly, i.e. before the turning moment affects the inertia of the head momentum, and altering the face geometry (square to the line of travel).

It therefore can be concluded that the flexible shaft design does not have to resist a turning moment, resulting from a ball impact with this type of head design.

Apart from contravening the rules, string instead of a shaft would not be very practical.

However, a shaft with a substantial amount of flexibility, conforming to the rules of golf, will achieve the same effect as the string, and combined with the head design creates a putter with performance characteristics far more appropriate to the mechanical requirements of putting.

For longer or uphill putts, backswing distances may not be enough to effect the ball travel to the hole. Once backswing control is achieved on the shorter putts, a small amount of force can be applied to the backswing, deflecting the invented putter shaft to get the distance. Even though the shaft deflects, it will not detract from the accuracy demanded.

In fact the player will get a much better 'feel' of the headweight force with the flexing shaft, *j enabling a much greater stroke control than ever experienced from a rigid shaft putter.

The shaft can be made of fibre glass, carbon fibre, steel, plastic or any other suitable material that will be strong enough for general handling and for the most extreme force likely to occur when executing the putt stroke. As the shaft has to be equally flexible all around (360 20 degrees, to comply with the rules of golf) its preferred shape should be circular. Along the length, it can be parallel or tapered, the butt end should be a tube at least 250 mm long, having a diameter size to suit a standard grip and be of rigid construction, to accommodate a grip for the player to hold **the putter assembly. The remainder of the shaft should be constructed out of suitable material, •assembled in such a manor as to be flexible, and the tip end strong enough to suitably fasten the 25 putter head to.

One form of the invention is hereby described with reference to the accompanying drawings in which:- FIG. 1 Shows the putter club assembly in 'side elevation'.

FIG. 2 Shows a 'plan view' of the putter head.

FIG. 3 Shows a 'face elevation' of the putter head.

FIG. 4 Shows a flexible shaft having the least amount of deflection claimed.

FIG 5 Shows a flexible shaft having the greatest amount of deflection claimed.

FIG. 6 Shows a mechanical testing, pendulum device.

Rjz 9 Description of the preferred embodiment;-- Referring to the figures 1, 2, and 3, a putter assembly includes a handle, 1, being a standard grip attached to the rigid, butt end of the shaft, the shaft, 2, being a flexible portion, the tip of which is connected to the head, 4, by a hosel, 3, the head, 4, having a top face with an alignment groove, 5, set at 90 degrees to the front face, 6, a front face, 6, having a degree of loft, 8, the shaft socket or hosel, 3, being set to one side of the groove, 5, at an angle, 7, to suit the player.

Referring to figure 4, a blank flexible shaft, 2, not having grip or head attached, is fi:ed in a horizontal position at the rigid, 250 mm long butt end, 1, by restraining the top at the end, 6, and underneath 250 mm from the butt end, 7, leaving the tip end free to suspend a 500 gram weight, the s fts deflection, 4, being measured vertically at 30 mm, being the minimum amount of deflection required for this putter assembly.

Referring to figure 5, a blank flexible shaft, 3, not having a grip or head attached, is fixed in a horizontal position at the rigid, 250 mm long butt end, 1, by restraining the top at the end, 6, and underneath 250 mm from the butt end, 7, leaving the tip end free to suspend a 500 gram weight, the shafts deflection, 5, being measured vertically at 150 mm, being the maximum amount of deflection required for this putter assembly.

Referring to figure 6, is a labelled diagrammatic view of a putter head, suspended by two strings from a bar secured at a height of 1200 mm above the ground, the side elevation demonstrating;- the pendulum action of the backswing, the backswing distance, its relationship with S 20 the ball distance, that a rigid shaft is not necessary, its consistent accuracy in holing the ball.

SoThe object of the invention is to distingui.h between the mechanical concepts of fairway club design and putting club design, to create the invented putter, enabling improved putting performance for the golf player. In a preferred embodiment of the invention, the mechanical o •concepts are addressed by selecting a shaft, made to deflect a required amount when tested with a 25 500 gram weight, then attaching a purpose designed head of known weight to this shaft.

S"With the foregoing in view, this invention in one aspect resides a light impact club assembly e including:a club head attached to an elongated tubular shaft having a club head secured to the tip end, with the opposite butt end comprising a grip. The shaft having a uniform flexible zone, between the head and the grip, the degree of flexibility, being determined by fixing a blank shaft in a horizontal position at the grip or butt end, with a restraining point on thr top of the butt end together with a restraining point underneath the shaft 250 mm from the butt end, having the tip horizontally disposed, is strained from normal unstrained attitude at zero, to deflect, an amount between 30 mm and 150 mm measured vertically, under the influence of a 500 gram weight suspended from a point at the tip end, being 800 mm from the butt end.

7T& RAZ/ If Ljj 0 The club head, having a flat striking face width no greater than 60 mm and a head weight selected between 300 grams to 450 grams, to have the head mass evenly distributed behind the face, to also include a centre rear projection all of which to be smoothly radiusd.

The combined head and shaft assembly, having the shaft deflection related to the headweight by selecting it from a scaled ratik,, extending from; a larger headweight attached to a shaft with a smaller deflection, to a smaller headweight attached to a shaft with a larger deflection, and the top surface of the club head being generally flat, includes a shallow grooved, printed or painted line, extending from the top centre of the face, to the centre rear of the projection, being degrees to the face, being parallel to the line of ball travel, set to one side of the line to suit a right or left handed player, a hosel or hole being of suitable size to attach the shaft, is set from a vertical plane, at an angle between 11 degrees to 20 degrees toward the player, the angle selected to suit the players size and stance.

The said shaft can be made 900 mm in length, from which it would be cut to a length to suit the player, the flexibility of which must be uniform in circumference and determined from an 800 mm portion of the 900 mm blank shaft. The flexibility being selected from a deflection range between 30 mm and 150 mm, measured vertically when fixed at the butt end and supporting a 500 gram weight at the tip end.

The said putter club head will have a striking face width, no greater than 60 mm and a loft angle, selected between 0 degrees and 3 degrees from a vertical plane, sloping from the bottom 20 edge of the face, to the top edge toward the rear.

A club assembly having a grip attached to the butt end of the shaft, the grip area of the shaft being rigid for the length of the grip and of suitable size to accommodate the grip. The whole club assembly having a preferred flexibility to headweight ratio consisting of a 400 gram head being S attached to a shaft having a 45 mm deflection, wherein the flexibility will be of such magnitude as to 25 provide a satisfactory response by deflecting sufficiently, to inform the player of any unnecessary movements to the stroke requirements of putting.

"Player performance and response with the invented putter, will determine the preferred headweight and shaft flexibility. Trials would indicate learner preference to a more flexible shaft and the more experienced players a less flexible shaft.

A putter, having a preferred head weight of 400 grams attached to a shaft having a flexibility of 45 mm deflection, determined by previously described methods, would be the most preferred combination to give a player tangible, manifest feedback and response to improve the player's performance.

It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as claimed in the following claims.

Claims (9)

1. A golf club implement including:- a club head; and an elongated tubular shaft having a club head secured to the tip end, with the opposite butt end comprising a grip; and the shaft having a uniform flexible zone between the head and the grip; and the said shaft will have a degree of flexibility, which will be determined by fixing a blank shaft in a horizontal position at the grip or butt end, witl- a restraining point on the top of the butt end together with a restraining point underneath the shaft 250 mm from the butt end, having the tip horizontally disposed, is strained from normal unstrained attitude at zero, to deflect, an amount between 30 mm and 150 mm measured vertically, under the influence of a 500 gram weight suspended from a point at the tip end, being 800 mm from the butt end and the club head having a flat striking face width no greater than 60 mm; and having a head weight selected from a range between 300 grams to 450 grams; and i the head having an evenly distributed mass behind the face, including a centre rear projection all smoothly radiusd; and having the shaft deflection related to the headweight by selecting it from a scaled ratio, extending from; a larger headweight attached to a shaft with a smaller deflection, to a smaller headweight attached to a shaft with a larger deflection; and the top surface of the club head being generally flat, includes a shallow grooved, printed or painted line, extending from the top centre of the face, to th3 centre rear of the projection, being 90 degrees to the face, being parallel to the line of ball travel; and having a hosel or hole incorporated on the top surface of the head, set to one side of the line to suit a right or left handed player, the hosel or hole being of suitable size to attach the shaft, set from a vertical plane, at an angle between 11 degrees to 20 degrees toward the player, the angle selected to S suit the players size and stance.

2. A club assembly as claimed in claim 1, wherein said shaft is the shaft of a golf club putter, which will hce its flexibility determined by using an 800 mm portion of a 900 mm shaft, fro, n which the shaft is cut to a length to suit the player.

3. A club assembly as claimed in any one of the preceding claims, wherein said shaft is made to have a uniform deflection, selected from the range between 30 mm and 150 mm, measured vertically, determined by, a blank shaft restrained horizontally over 250 mm at the butt end, 800 mm from which has a 500 gram weight suspended from a point on the shaft, to produce the selected deflection.

4. A club assembly as claimed in any one of the preceding claims, wherein the butt end of the shaft will be a rigid tube at least 250 mm long, having a diameter size to suit a standard grip for the _player to hold the putter assembly.

A club assembly as claimed in any one of the preceding claims, wherein the headweight is related to the shaft deflection measurement, the headweight being selected from a weight between 300 grams to 450 grams.

6. A club assembly as claimed in claim 1, wherein the club head face will have a fiat striking face the width of which will be no greater than 60 mm set at a loft angle between 0 degrees to 3 degrees from a vertical plane, sloping from the bottom edge of the face, to the top edge towa;d the rear.

7. A club as ombly as claimed in any one of the preceding claims, wherein the preferred flexibility of a club assembly, will have a 400 gram head attached to the tip end of a shaft havin9 a deflection of 45 mm, as determined in previous claims.

8. A club assembly as claimed in any one of the preceding claims, wherein the shaft flexibility is determined by attaching a head of a selected weight to a shaft having a selected deflection, the selected weights and deflections being within the scaled ratio parameters set in claim 1.

9. A club assembly as claimed in any one of the preceding claims, wherein the flexibility will be of S• such magnitude as to provide, bL* not detract from, a satisfactory response by deflecting sufficiently, to inform the player of any unnecessary movements to the stroke requirements of putting. A club assembly as substantially hereinbefore described with reference to any one of the accompanying drawings. DATED THIS EIGHTEENTH DAY OF DECEMBER 1996. Lawson GIDDENS L0 O:\C °oo °•I ~ro•F ABSTRACT A light impact golf club putter assembly, including a -lub head, a handle assembly including shaft means connecting said handle portion to said club head, and feedback means providing discernible feedback of the club head movement to the user. Ir a preferred embodiment of the invention the shaft means is sufficiently flexible to deflect visibly under the influence of a force applied through the grip, by the player, and gravity acting upon the inertia of the club head mass, the different forces acting upon the flexible shaft to make it deflect sufficiently for the player to visibly distinguish between the necessary movements to correctly execute a putt stroke, and the unnecessary movements that would detract from a correct stroke. The club head mass being selected from a weight range between 300 grams and 450 grams, the said shafts deflection, measured by fixing the shafts butt end horizontally, a 500 gram weight suspended 800 mm from the butt end, vertically displaces the tip end from the horizontal, to enable a shaft to be selected from E ,nge between 30 mm and 150 mm, the head and shaft components of the invented putter club assembly, being selected by a weight to deflection ratio respectively. 7 .c I iI I