GB2258157A - Golf training club. - Google Patents

Abstract

A golf training club includes a hinge which comprises male and female members (7 and 8), the female member having two side limbs (12) which are pivoted to the male member on a pivot pin, a spring (21) made of a strip of spring material, having retaining means, is removably secured to the female member at the base between the side limbs, and the male member has projecting hardened spherical surfaces (20) such that when the hinge is assembled the spherical surfaces engage the retaining means in the strip of spring material to hold the hinge in its unhinged position. <IMAGE>

Description

GOLF TRAINING CLUB This invention relates to golf training clubs and more particularly to a hinge for a golf club which is used to practice a golf swing.

Golf training clubs are already known which incorporate a hinge in the club shaft which pivots when the club is incorrectly swung and remains unhinged when the club is swung properly.

These known clubs have the disadvantage that at a point of connection between male and female members of the hinge i.e. the pivot point, the end of the male member wears due to the constant pressure on a ball bearing from a coiled spring within the female member causing the hinge to become loose. The readjustment can only be carried out by a recommended agent or when returned to the manufacturers. The continual adjustment is also known to wear the hinge pivot pin to excess rendering the product inoperative and as the known hinge is a sealed unit, would require to be replaced in total.

An aim of the present invention is to provide an improved hinge for a golf training club which overcomes the above mentioned disadvantages.

According to the present invention there is provided a hinge for a golf training club, comprising a male member and a female member, the female member having two side limbs which are pivoted to the male member on a pivot pin, a spring made of a strip of spring material, having opposing retaining means, being removably secured to the female member at the base between the side limbs, the male member having hardened spherical surfaces projecting from the male member such that when the hinge is assembled the spherical surfaces engage the retaining means in the strip of spring material to hold the hinge in its unhinged position.

Preferably, the strip of spring material is removably secured to the female member by two threaded screws.

Conveniently the pivot pin is a bolt which has a slotted head at one end and a screw thread at its other end which screws into a screw threaded hole in one limb of the female member.

In a preferred construction the male and female members are cylindrical and have longitudinal axial holes formed in their ends to receive machined parts of a golf club shaft.

The present invention also extends to a golf club incorporating a hinge as set forth in the four preceding paragraphs.

Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is an elevational view of a golf club fitted with a hinge according to the present invention; Fig. 2 is an exploded view of the golf club hinge on an enlarged scale; Fig. 3 is an enlarged fragmentary elevation of the golf club hinge in its hinged position; Fig. 4 is a similar view to Fig. 3 with the golf club hinge in its unhinged position; Fig. 5 is a plan view of the hinge shown in Fig. 4; Fig. 6 is an enlarged fragmentary axial section of the golf club hinge; and Fig. 7 is a cross-section of the hinge shown in Fig. 6.

The golf training club illustrated in Fig. 1 comprises a stepped shaft 1 having a hand grip 2 at one end and a club head 3 at the other end. The shaft 1 has a hinge generally indicated at 4 which is located at the lower end of the shaft.

In an example using a five-iron, where the overall length of the shaft including the club head is 1,008 mm, the centre point of the hinge is 162 mm to the hosel and 742 mm to the end of the hand grip. The overall length of the grip may be 252 mm for a 'Trainer Grip' and 270 mm for a 'Standard Grip'. The hinge is positioned so that its pivot axis lies parallel to the club face 5 and its lower edge 6.

An exploded view on an enlarged scale of the club hinge is shown in Fig.2 and comprises a male member 7 and a female member 8. The members are manufactured from a high quality stainless steel and are generally cylindrical in shape, each having an aperture 9 drilled axially of the cylindrical member. These apertures receive the machined ends of the club shaft 1 which are secured in the apertures 9 by an adhesive and locked against rotational movement by a 3 mm rivet (not shown) which passes through a drilled hole 10 in the respective male and female members and the ends of the parts of the shaft 1.

With reference now to Figs. 6 and 7, the female member 8 has two limbs 11 and 12 between which is located a stepped flat-sided projection 13 of the male member 7, the male and female members being hinged together by a stainless steel bolt 14 which has a slotted head 15 to receive a screwdriver at one end and a screw-thread 16 at the other end which screws into a screw threaded hole in the limb 11 of the female member. The bolt 14 passes through a bush 17 of a sintered material providing a self-lubricating pivot surface for the bolt, and through holes 18 formed in the limbs 11 and 12.

Located in a lower stepped portion of the male member is a hole 19 for a 3/16 inch (4.76 mm) ball bearing 20 which is held in a freely rotatable state in the hole 19 by peening the outer edges of the hole over the ball bearing 20. A rectangular U-shaped strip of spring steel 21 is held between the limbs 11 and 12 of the female member in a recess 22 in its base and removably locked therein by two retaining screws 23 which pass through holes in the base of the U-shaped spring and screw into threaded holes 24 in the recess 22. In addition to the holes 18 in the limbs 11 and 12 the female member has two spring tensioning screws 25 which can be adjusted to tension the sides of the U-shaped spring should the spring lose its compression.The sides of the spring have opposing apertures 26 which when the hinge is assembled engage the rotatable ball bearing 20 to retain the hinge in its unhinged position to a preset pressure of 14 lbs per squre inch. Above this pressure the spring pressure is overcome and allows the hinge to pivot.

If after 100,000 swings of the club the spring becomes weak and loses its compression, the spring can be adjusted by screwing in the spring tension screws 25.

Should the spring 21 lose its compression so that it is below 14 lbs per square inch, then it can be easily replaced by unscrewing the bolt 14 separating the male and female members and replacing the spring 21 with a new spring by unscrewing the retaining screws 23.

Figs. 3 to 5 show detailed views of the hinge in its hinged and unhinged positions. The ends of the limbs 11 and 12 of the female member 8 have radiused ends 26 which seat in radiused sides 27 of the male member 7 providing a clearance when the hinge is pivoted.

The positioning of the hinge at the correct location within the shaft 1 of the golf training club provides a perfectly balanced club. If the club is incorrectly swung the hinge pivots, providing the user or teacher with an immediate indication of a fault at that point of the swing enabling the fault to be corrected.

If however, the swing and timing are correct, the hinge remains unhinged enabling the user to hit a regular golf shot. The use of the training club will provide the user wth a training device which, when swung in accordance with the instructions, will enable both the inexperienced and scratch golfers to effect their swing pattern or to fine tune 'groove' the user's existing swing.

Various modifications may be made to the golf training club and improved hinge. For example, the hand grip may be moulded to accommodate the finger grip of the user to correctly position the striking face and lower edge of the club head when taking up a golf stance. The moulded grip will enable the user to gain what is known as the 'Vardon' grip that the majority of professional golfers and teachers recommend.

Although the hinge has been described as being manufactured of stainless steel, it can of course be made of other materials such as a metal alloy or a rigid plastics material.

The rectangular spring strip has been described as being secured to the female member by two screws, but it can be held by a different number of screws.

The hinge has also been described as having drilled apertures to receive the ends of the machined golf club shaft. However, in an alternative construction the ends of the hinge members may be of reduced diameter to be inserted into the hollow ends of the machined golf shaft.

Claims (17)

CLAIMS:

1. A hinge for a golf training club comprising a male member and a female member, the female member having two side limbs which are pivoted to the male member on a pivot pin, a spring made of a strip of spring material, having retaining means, being removably secured to the female member at the base between the side limbs, the male member having hardened spherical surfaces projecting from the male member such that when the hinge is assembled the spherical surfaces engage the retaining means in the strip of spring material to hold the hinge in its unhinged position.

2. A hinge as claimed in Claim 1, wherein the retaining means are apertures in the opposing sides of the strip of spring material.

3. A hinge as claimed in Claim 1 or 2, wherein the strip of spring material is removably secured to the female member by two threaded screws.

4. A hinge as claimed in any of Claims 1 to 3, wherein the pivot pin is a bolt with a slotted head at one end and is screw-threaded at its other end which passes through a hole in one limb of the female member and screws into a screw-threaded hole in the other limb.

5. A hinge as claimed in any preceding claim, wherein the male and female members are cylindrical and have longitudinal axial holes formed in their ends to receive machined parts of a golf club shaft.

6. A hinge as claimed in Claim 5, wherein the male and female members have rivets which pass through the machined ends of the parts of the golf club shaft to hold the shaft against rotation relative to the hinge.

7. A hinge as claimed in any preceding claim, wherein the spring made of a strip of spring material is of rectangular U-shape and is made of spring steel.

8. A hinge as claimed in any preceding claim, wherein the spherical surfaces are formed by a ball bearing made of a hardened stainless steel and is rotatably held in an aperture in the male member by peening the edges of the aperture over the ball bearing.

9. A hinge as claimed in any preceding claim, wherein the limbs of the female member have tension adjusting screws to tension the force of the strip of spring material against the spherical surfaces. ~

10. A hinge as claimed in any preceding claim, wherein the female member has a recess in the base between the side limbs to receive the strip of spring material.

11. A hinge for a golf training club comprising a male member and a female member, the female member having two side limbs wherein a spring loaded latch is located between the male member and the limbs of the female member.

12. A golf club incorporating a hinge as claimed in any preceding claim.

13. A golf club as claimed in Claim 12, wherein the shaft has an overall length of 1,008 mm and the centre pivot of the hinge is 162 mm to the hosel and 742 mm to the end of a hand grip.

14. A golf club as claimed in Claim 13, wherein the hand grip is a training grip with an overall length of 252 mm.

15. A golf club as claimed in Claim 13, wherein the hand grip is a standard grip with an overall length of 270 mm.

16. A hinge for a golf training club substantially as hereinbefore described with reference to and as shown by the accompanying drawings.

17. A golf club for training purposes substantially as hereinbefore described with reference to and as shown by the accompanying drawings.