The present invention relates to golf putters, and particularly an alignment aid in the custom fitting of golf putters to the requirements of individual users, where either left or right handed, and as a teaching tool.

It is important that a golf putter, whose purpose is to propel a golf ball along the ground of a prepared surface, referred to as a green, provides a consistent strike and thus imparts consistent momentum to the golf ball.

This momentum is transferred from the golf putter to the golf ball by the movement of the putter head when swung by the golfer. It is a requirement that this momentum be transferred consistently to the golf ball for a given force of impact, as otherwise a variable amount of momentum will be transferred, causing the golf ball to be propelled a variable distance.

Certain other characteristics are also desirable, particularly that the golf putter should not twist in the hands as the golf ball is struck. If the point of contact is away from the "sweet spot" of the golf putter, the putter head, which is disposed at right angles to the intended line of the golf ball, will twist away from the intended line of the golf ball and the golf ball will not be propelled in the correct direction. The "sweet spot" is normally found by tapping the face of the putter head when the golf putter is held in the finger tips at the end of the grip and the golf putter hangs vertically downwards. If the putting face is tapped near the toe or heel on conventionally-balanced golf putters, then the putting face will twist in one of the respective directions. If the putting face does not deflect off axis when so tapped, then the "sweet spot" has been found.

It is also desirable to provide that the "sweet spot" of the golf putter is in line with the shaft of the golf putter, as this configuration minimizes the possibility of twisting.

Good putting is possible only if the golfer has a good putting technique based on good putting mechanics. In order to have a solid, repetitive putting stroke, the golfer's eyes should be over the golf ball and the golfer's hands need to be below the shoulders, and, in order to meet these requirements, the golf putter should be made such as to fit the physical characteristics of the golfer precisely.

Complying with these principles allows a golfer to move his/her hands and the putter head along the intended line of the golf ball towards and past the hole, thereby allowing the putter head to stay at right angles to that line for as long as possible.

The fitting device of the present invention has been developed to enable golf putters to be custom fitted to golfers, in particular to be made to the correct length and to have the correct lie. The lie is defined as the angle between the putter head and the shaft. If the lie angle is too small, the golfer will find it difficult to position the putter head under his/her eyes without the toe of the golf putter being raised from the ground. Conversely, if the lie angle is too great, then the heel of the putter will be raised from the ground. In both instances, hitting the ground with either the heel or the toe of the golf putter before hitting the golf ball, would result in the golf putter being twisted off the intended line of the golf ball and the golf ball being propelled dramatically off line.

Furthermore, in order to ensure that the shaft of a golf putter is of the correct length, an adjustable shaft is provided which allows the eyes of the golfer to be positioned over the golf ball and the hands of the golfer to be positioned below his/her shoulders. The lie angle can then be adjusted to ensure that the head of the golf putter is flat to the ground.

It is an aim of the present invention to allow for custom fitting of golf putters to golfers, in which both the length of the golf putters and the lie angle of the golf putters can be configured to suit the golfers.

In one aspect the present invention provides a golf putter, comprising: a head assembly which includes a putting head which has a striking face, and at least one alignment beam generator unit which includes an alignment beam generator for generating an alignment beam; and a shaft assembly which comprises a shaft which is connected to the head assembly and a grip unit by which a user grips the fitting device.

In one embodiment the golf putter is a golf fitting putter.

In one embodiment the at least one alignment beam is projected forwardly of the striking face of the putting head.

In one embodiment the at least one alignment beam is projected substantially perpendicular to the striking face of the putting head. In one embodiment the at least one alignment beam is projected through the striking face of the putting head.

In one embodiment the putting head includes at least one fitting and each alignment beam generator unit includes a counterpart fitting, by which the at least one alignment beam generator unit is removably fitted to the putting head.

In one embodiment the fittings comprise screw fittings.

In one embodiment the at least one fitting on the putting head includes a through bore through which the respective alignment beam is projected.

In one embodiment the at least one fitting on the putting head includes a window element which closes the through bore.

In one embodiment the alignment beam generator comprises a laser pointer.

In one embodiment the at least one alignment beam generator unit includes a switch which is actuated to actuate the alignment beam generator when the at least one alignment beam generator unit is operably fitted to the putting head.

In one embodiment the at least one alignment beam generator unit is screw fitted to the putting head, and the switch is actuated/de-actuated by rotation of the at least one alignment beam generator unit.

In one embodiment the head assembly includes first and second alignment beam generator units for generating first and second spaced alignment beams.

In one embodiment the first and second alignment beam generator units are located towards opposite ends of the striking face of the putting head.

In another aspect the present invention provides a golf putter system, comprising: the above-described golf putter; and an alignment screen which includes at least one alignment mark onto which the at least one alignment beam is projected.

In one embodiment the alignment screen comprises first and second spaced alignment marks. In one embodiment the alignment marks are provided by a horizontal line and first and second spaced vertical lines.

In a further aspect the present invention provides a method of fitting a golf putter using the above^described golf putter system.

In a still further aspect the present invention provides a method of training a golf putting stroke using the above-described golf putter system.

In yet another aspect the present invention provides an alignment beam generator unit for fitting to a putting head of a golf putter, wherein the alignment beam generator unit comprises a housing which includes a fitting for fitting to a counterpart fitting of the putting head and an alignment beam generator housed within the housing.

In one embodiment the alignment beam generator unit includes a switch which is actuated to actuate the alignment beam generator when the alignment beam generator unit is operably fitted to the putting head.

In one embodiment the alignment beam generator unit is screw fitted to the putting head, and the switch is actuated/de-actuated by rotation of the alignment beam generator unit.

In one embodiment the alignment beam generator is a sliding fit within the housing, and the housing includes an internal flange which is configured to actuate the switch when the alignment beam generator is biased into the housing on fitting the alignment beam generator unit to the fitting of the putting head.

In another embodiment the housing and the alignment beam generator are provided as a single, fixed integral unit.

In one embodiment the alignment beam generator comprises a laser pointer.

Preferred embodiments of the present invention will now be described hereinbelow by way of example only with reference to the accompanying drawings, in which:

Figure 1 illustrates a rear view of a golf fitting putter of a golf putter fitting system in accordance with a preferred embodiment of the present invention; Figure 2 illustrates a front view of the golf fitting putter of Figure 1;

Figure 3 illustrates one side view, in part section, of the golf fitting putter of Figure 1;

Figure 4 illustrates the other side view, in part section, of the golf fitting putter of Figure 1;

Figure 5 illustrates a plan view of the head assembly of the golf fitting putter of Figure 1;

Figure 6 illustrates an enlarged view of detail A in Figure 5;

Figures 7(a) to (d) illustrate, in enlarged scale, front, rear, plan and vertical sectional views of the boss member of the golf fitting putter of Figure 1;

Figure 8(a) illustrates a side view of the alignment unit of the golf fitting putter of Figure 1;

Figure 8(b) illustrates an enlarged view of detail B in Figure 8(a);

Figure 8(c) illustrates a longitudinal sectional view of the alignment unit of Figure 8(a);

Figure 9 illustrates a part-sectional rear view of the shaft assembly of the golf fitting putter of Figure 1;

Figures 10(a) and (b) illustrate the steps in adjusting the length of the golf fitting putter of Figure 1;

Figures ll(a) to (c) illustrate the steps in re-configuring the golf fitting putter of Figure 1 between the left-handed and right-handed configurations;

Figure 12 illustrates a rear view of the golf fitting putter of Figure 1 in a left- handed configuration;

Figure 13 illustrates a rear view of the golf fitting putter of Figure 1 in a right- handed configuration; Figures 14(a) to (d) illustrate, in enlarged scale, front, rear, plan and vertical sectional views of a boss member in accordance with one embodiment of the golf fitting putter of Figure 1; and

Figure 15 illustrates a front view of an alignment screen of a golf putter fitting system in accordance with a preferred embodiment of the present invention.

The golf putter fitting system comprises a golf fitting putter 1 and an alignment screen 2 for use with the golf fitting putter 1.

The golf fitting putter 1 comprises a head assembly 3, and a shaft assembly 5 which is connected to the head assembly 3 and by which a user grips the golf fitting putter 1.

The head assembly 3 comprises a head unit 7 to which the shaft assembly 5 is connected, a lie angle indicator 11, in this embodiment an angular scale, which is attached to the head unit 7, in this embodiment by screws 15, such as to enable measurement of the lie angle of the head unit 7 relative to the shaft assembly 5, and first and second alignment beam generator units 13, 13 for generating alignment beams AB, in this embodiment laser beam pointers, which are attached to the head unit 7, as will be described in more detail hereinbelow.

Referring to Figures 3 to 7, the head unit 7 comprises a head member 17, which includes a striking face 19 which is used to strike a golf ball, a coupling element 21, in this embodiment a cylindrical projection, which extends rearwardly from the head member 17, in this embodiment at a central position along the length thereof, and first and second fittings 23, 23, in this embodiment at positions towards the opposite ends of the head member 17, for receiving respective ones of the first and second alignment beam generator units 13, 13, such as to provide a pair of spaced, parallel alignment beams AB, and a boss member 25 which is connected to the shaft assembly 5 and movably coupled to the head member 17, such as to allow for adjustment of the lie angle of the head member 17 relative to the shaft assembly 5.

In this embodiment the fittings 23, 23 each include a through bore 26 through which the respective alignment beam AB is projected, and a window element 27 which closes the through bore 26 and is flush with the striking face 19 of the head member 17. In this embodiment the window element 27 is formed of sapphire glass and has a diameter of 5 mm and a thickness of 3 mm. In this embodiment the fittings 23, 23 are screw fittings to which the alignment beam generator units 13, 13 are screw fitted. In an alternative embodiment the fittings 23, 23 could be push fittings to which the alignment beam generator units 13 are push fitted.

In this embodiment the coupling element 21 includes a screw-threaded bore 28 for receiving a screw-threaded shaft 49 of a locking member 48, as will be described in more detail hereinbelow.

In this embodiment the boss member 25 includes front and rear faces 31, 33, where the front face 31 is configured such as to abut a rear surface of the head member 17, a recess 35, in this embodiment a cylindrical recess, which is disposed in one, the front face 31 thereof and is of complementary shape to the coupling element 21 at the rear of the head member 17, such that the boss member 25 is rotatable relative to the head member 17 in a first vertical plane, which is substantially parallel to the striking face 19 of the head member 17, thereby enabling adjustment of the lie angle of the head member 17 relative to the shaft assembly 5, and a clearance aperture 37 which extends through the rear face 33 in correspondence with the screw-threaded bore 28 in the coupling element 21, such as to allow the screw-threaded shaft 49 of the locking member 48 to extend therethrough.

In this embodiment the boss member 25 further includes a bore 41, in this embodiment a cylindrical bore, which is disposed in the upper end thereof for fixedly receiving the lower, distal end of the shaft assembly 5.

In this embodiment, as particularly illustrated in Figures 8(a) to (c), the alignment beam generator units 13, 13 each comprise a housing 42 which is fitted to a respective one of the fittings 23, 23, and an alignment beam generator 43 which is housed, here as a close sliding fit, within the housing 42, such as to provide for the generation of an alignment beam AB which is centred on the longitudinal axis of the housing 42. In an alternative embodiment the housing 42 and the alignment beam generator 43 could be provided as a single integral unit.

In this embodiment the housing 42 includes an elongate cavity 44 in which the alignment beam generator 43 is housed, here as a close slideable fit, such as to ensure the centring of the alignment beam generator 43 on the longitudinal axis of the housing 42. In this embodiment the cavity 44 includes an internal flange 45 which is configured to actuate a switch 47 of the alignment beam generator 43 when the alignment beam generator 43 is biased into the cavity 44 on fitting the housing 42 to one of the fittings 23 of the putter head 17.

In this embodiment the housing 42 includes a fitting 46, here a screw fitting, at one, the forward, end thereof which is counterpart to the fittings 23, 23 of the putter head 17, by means of which the housing 42 is fitted to the putter head 17.

In this embodiment, as particularly illustrated in Figure 8(c), the alignment beam generator 43 includes a switch 47 in a surface thereof, here a lateral surface thereof, which is actuated by engagement with the internal flange 45 within the cavity 44 of the housing 42 when the housing 42 is fitted to one of the fittings 23, 23. With this configuration, the alignment beam generator 43 can in this embodiment be switched on and off simply by rotating the housing 42, thereby avoiding the need to remove the alignment beam generator units 13, 13 from the putter head 17.

The head unit 7 further comprises a locking member 48 for locking the boss member 25 in a desired angular position relative to the head member 17. In this embodiment the locking member 48 comprises a screw-threaded shaft 49 which extends through the clearance aperture 37 in the rear face 33 of the boss member 25 and is threadedly engaged with the screw-threaded bore 28 in the coupling element 21, a knob 50 which is attached to one, the rear, end of the screw-threaded shaft 49, such as to provide for rotation of the screw-threaded shaft 49, and a biasing element 51 which is located about the screw-threaded shaft 49 at the forward end of the knob 50, such as to bias the boss member 25 against the rear surface of the head member 17.

In this embodiment, referring particularly to Figure 6, the biasing element 51 comprises first and second washers 52, 53 and a spring 55, in this embodiment a spring washer, which is disposed between the washers 52, 53, such as to bias apart the washers 52, 53 and thereby promote the frictional engagement between the rear surface of the head member 17 and the front face 31 of the boss member 25.

In another embodiment the biasing element 51 could be formed from a resilient material, such as a rubber material. In an alternative embodiment the biasing element 51 could be replaced by a spacer element which acts frictionally to engage the forward end of the knob 50 and the rear face 33 of the boss member 25.

With this configuration, through operation of the knob 50, the locking member 48 can be loosened to allow the lie of the shaft assembly 5 to be set relative to the head member 17 and subsequently tightened to lock the boss member 25, and hence the shaft assembly 5 as connected thereto, to the head member 17, such as to fix the lie angle of the shaft assembly 5 relative to the head member 17.

Referring particularly to Figures 3 and 4, the shaft assembly 5 comprises a shaft 61, one, the lower, end of which is connected, in this embodiment fixedly connected, to the bore 41 in the boss member 25, and a grip unit 63 which is disposed to the other, upper end of the shaft 61 by which a user grips the golf fitting putter 1.

The shaft 61 includes first and second oppositely-directed axial slot sections 65, 67 which extend axially along a length of the shaft 61 at one, the upper, end thereof, and are configured captively to receive a locking element 83 of a grip locking member 75 when the grip unit 63 is in a respective one of a left-handed or right-handed configuration, as will be described in more detail hereinbelow.

Referring to Figure 9, the shaft 61 further includes a circumferential slot section 69, in this embodiment semi-circular, which interconnects the first and second axial slot sections 65, 67, in this embodiment at the upper ends thereof, such as to allow the locking element 85 of the grip locking member 75 to be moved selectively between the first and second axial slot sections 65, 67, and thereby enable the grip unit 63 to be moved between the left-handed and right-handed configurations.

In this embodiment the shaft 61 further includes a graduated scale 71, here marked in the imperial scale of inches which is still the measurement of choice in the golf industry, though it will be understood that any measurement unit could be employed. In this embodiment the graduated scale 71 enables the required length of the shaft 61 to be determined without recourse to the use of any other measuring device.

The grip unit 63 comprises a grip member 73, which is slideably mounted to the shaft 61 such as to be movable axially therealong, and a grip locking member 75, which is operable to allow for locking of the grip unit 63 in a desired position relative to the shaft 61.

The. grip member 73 includes a bore 77 which receives the shaft 61 and a collar 79, which is disposed to one, the lower, end of the grip member 73 and includes a screw-threaded through bore 81, which receives a locking element of the grip locking member 75, as will be described in more detail hereinbelow.

In this embodiment the grip locking member 73 comprises a screw-threaded, locking element 83 which is threadedly engaged with the screw-threaded bore 81 in the grip member 73, and a knob 85 which is attached to one, the outer end of the locking element 83, such as to provide for rotation of the locking element 83 and frictional engagement between the distal end of the locking element 83 and the shaft 61, such as to lock the grip unit 63 in a desired position axially relative to the shaft 61. In this embodiment the distal end of the locking element 83 can be formed of a material having a low coefficient of friction, such as a plastics material,, so as to facilitate, when desired, the free movement of the locking element 83 within the axial and circumferential slot sections 65, 67, 69.

With this configuration, as illustrated in Figures 10(a) and (b), through operation of the knob 85, the grip locking member 75 can be loosened to allow the position of the grip unit 63 on the shaft 61 to be set to a desired height, and subsequently tightened to lock the grip unit 63 to the shaft 61, such as to fix the effective length of the shaft 61, in terms of the separation of the head member 17 from the grip member 73.

Also, as illustrated in Figures ll(a) to (c), this configuration allows the grip unit 63 to be set to either one of a left-handed or right-handed configuration. This is achieved by first loosening the grip locking member 75, through operation of the knob 85, and raising the grip unit 63 to the uppermost position on the shaft 61, such that the grip locking member 75 is drawn to the upper end of the one of the axial slot sections 65, 67, in which position the locking element 83 of the grip locking member 75 is located at the circumferential slot section 69 in the shaft 61. The grip unit 63 is then rotated through 180 degrees about the shaft 61, such that the grip locking member 75 is in a position corresponding to the upper end of the other one of the axial slot sections 65, 67. The grip unit 63 is then lowered, such that the locking element 83 of the grip locking member 75 passes down the other one of the axial slot sections 65, 67. The position of the grip unit 63 can then be adjusted on the shaft 61, and the grip locking member 75 subsequently tightened to lock the grip unit 63 to the shaft 61, such as to fix the effective length of the shaft 61, in terms of the separation of the head member 17 from the grip member 73. Figures 12 and 13 illustrate the configuration of the golf fitting putter 1 for left-handed and right-handed fitting, respectively.

In one embodiment, as illustrated in Figures 14(a) to (d), the golf fitting putter 1 allows for adjustment of the loft angle of the shaft 61 relative to the putting face 19 of the head member 17.

In this embodiment the boss member 25, instead of including a bore 41 in which the distal end of the shaft 61 is fixedly connected, further comprises a pivotable support coupling 91 to which the distal end of the shaft 61 is connected, such as to allow for adjustment of the loft angle of the shaft 61 relative to the putting face 19 of the head member 17.

In this embodiment the support coupling 91 comprises a support element 93, here a pair of parallel, opposed supporting arms 95, 97 which extend from the upper end of the boss member 25, and a connector element 99 which is pivotally coupled between the supporting arms 95, 97 about a pivot 101, where the ends of the pivot 101 are located in respective ones of the supporting arms 95, 97.

In this embodiment the connector element 99 comprises a first, lower section 105 which is of a square section and configured to be a tight interference fit between the supporting arms 95, 97, such as to require the application of a predetermined force to cause the pivoting of the connector element 99 relative to the supporting arms 95, 97, and a second, upper section 107, here of a cylindrical section, over which the distal end of the shaft 61 is fitted.

In this embodiment the boss member 25 further includes a loft angle indicator 109, here an angular measurement scale, for measuring the loft angle of the shaft 61 relative to the putting face 19 of the head member 17. In this embodiment the loft angle indicator 109 is attached to the support element 93.

In a further embodiment, the golf fitting putter 1 allows for adjustment of the offset of the shaft 61 relative to the putting face 19 of the head member 17, for example, through the use of spacer elements.

In this embodiment the alignment screen 2, here in the form of an upstanding plate, includes two spaced alignment marks 121, 123, as defined by a horizontal line and two spaced vertical lines, which represent the required alignment of the golf fitting putter 1 and are intended to be aligned with the alignment beams AB generated by the alignment beam generator units 13, 13 of the golf fitting putter 1. Where the alignment beams AB are not aligned with the alignment marks 121, 123, either horizontally or vertically, the lie and/or loft of the head member 17 of the golf fitting putter 1 is adjusted as described hereinabove to provide the required alignment of the golf fitting putter 1.

Finally, it will be understood that the present invention has been described in its preferred embodiments and can be modified in many different ways without departing from the scope of the invention as defined by the appended claims.

For example, although the fitting system of the present invention is described in relation to a golf fitting putter 1, the fitting system also has application in relation to fitted putters, where the user can check his/her alignment of the fitted putter and as a teaching aid. In fitted putters, the fittings 23, 23 of the putter head unit 7, to which the alignment beam generator units 13, 13 are fitted, normally have weights fitted thereto, and these weights are removed to allow fitting of the alignment beam generator units 13, 13.

Further, in one modification the bore 77 of the grip member 73 can be formed of a material of a low coefficient of friction, such as a plastics material, so as to facilitate the free movement of the grip unit 63 over the shaft 61. Alternatively, the bore 77 of the grip member 73 could include one or more annular elements of such a material.