US3083969A

US3083969A - Long-handled, swingable driving instrument

Info

Publication number: US3083969A
Application number: US98374A
Authority: US
Inventors: Jr Claud H Bills
Original assignee: AXALINE GOLF CO
Current assignee: AXALINE GOLF CO
Priority date: 1961-03-27
Filing date: 1961-03-27
Publication date: 1963-04-02
Anticipated expiration: 1980-04-02

Description

3,083,969 Patented. Apr. 2, 163

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3,083,969 LONG-HANDLED, SWHNGABLE DRIVING INSTRUMENT Ciaud H. Bills, In, South Gate, Galif, nssignor to Axalme Golf Company, Sherman Galrs, Caiif., a corporation of California Fiietl Mar. 27, 1961, Ser. No. 93,374 Qlaims. (Cl. 273-80) The present invention relates to a long-handled, swingable driving instrument in which the handle or shaft is especially designed to control the flexing thereof when the instrument is swung.

A golf club, for example, is a driving instrument having a long handle or shaft, with a manual gripping means affixed to one end thereof and a driving head aflixed to its other end. As the golf club is swung the handle or shaft flexes or bends. Although this flexing or bending action cannot be visually observed it nevertheless has been successfully studied by means of high speed cameras operating at a rate of several hundred frames per second. The precise nature of .the flexing or bending action that takes place in the handle or shaft not only affects the driving power which the driving head is capable of imparting to a golf ball but may also affect the precision of the direction or aim of the thrust imparted to the golf ball.

According to the present invention a novel shaft construction is provided which permits individual design for optimum flexing or bending characteristics.

Another feature of the invention is the provision of means for absorbing unwanted shaft vibrations which occur while the golf club or other instrument is being swung.

With reference to golf clubs in particular, the types of construction heretofore known and used have involved a relatively small shaft diameter at its lower end, where the driving head is attached, and a relatively large diameter at its upper end where the gripping means is attached. There are a number of excellent reasons for this arrangement. The small diameter of the bottom end of the shaft minimizes wind resistance, which is considered to be necessary. The larger diameter of the upper end the shaft more readily fits the hand of the player. Furthermore, the golf club is in a sense comparable to a whip, and whips are traditionally of largest diameter at their handle end, hence the golf club simply would not look right if it had its largest diameter at the outer end.

So far as known to the applicant there has never been and dissatisfaction with conventional golf club construction, nor has any need been recognized for a new type of shaft or handle construction in a long-handled, swingable driving instrument. Apparently it has been commonly believed that conventional golf clubs have been yielding all the performance that such devices are inherently capable of yielding, and so far as the applicant is advised, he is the first to reach a diiferent conclusion.

One object of the invention, therefore, is to provide means for precisely con-trolling the flexing or bending action of a swingable handle or shaft.

Another object of the invention is to provide means for absorbing or damping upwanted vibrations that occur during the flexing or bending of a swingable shaft as it is being swung.

A further object of the invention is to provide a golf club capable of driving a ball much further than golf clubs heretofore available.

in accordance with the invention a hollow handle or shaft is integrally formed of metal, preferably a relatively light metal such as aluminum. The wall thickness of the 2 hollow shaft is made uniform throughout the length of the shaft, except that in a specific portion of the length of the shaft the wall thickness is reduced. Flexing or bending of the shaft then tends to be concentrated in the portion of its length having the reduced wall thickness.

A preferred feature of the invention is to form the reduced wall thickness of the metal in such a way as to avoid any discontinuity. That is, both the exterior and interior surfaces of the shaft are smoothly continuous surfaces, with the wall thickness changing gradually at both ends of the reduced thickness portion of the shaft.

Another feature of the invention, in its preferred form, is the inclusion in the hollow interior of the metal shaft of a very small quantity of foamed plastic material. This material breaks the interior of the shaft into distinct cells or pockets to an extent suificient to disrupt pressure waves that tend to develop in the air cavity within the shaft. Vibrations originating at various points in the shaft structure are therefore dissipated near their point of origin without an opportunity for an oscillatory or recirculating action.

With regard to golf clubs in particular, in accordance with the invention the old practice of making the shaft smaller at its lower end, to which the driving head is afiixed, is still followed. However, it is recognized that this type of construction normally tends to produce maximum flexing or bending of the shaft in its smallest diameter portion adjacent its lower end. in accordance with the invention it is also recognized that, although the smallest diameter portion needs to be at the lower end of the shaft, the maximum flexing action needs to be elsewhere. More specifically, the maximum flexing action needs to occur somewhere in the middle portion of the shaft. By utilizing a hollow metal shaft which tapers in diameter from its upper end to its lower end, and providing a reduced wall thickness in the middle region of the shaft length, a golf club of superior driving capabilities is achieved.

The objects and advantages of the invention will be more fully understood from the following description in conjunction with the accompanying drawing, in which:

FIGURE 1 is a side view, partially in cross-section, of a golf club in accordance with the invention;

FIGURE 2 is a longitudinal cross-sectional view of the golf club shaft;

FIGURE 3 is a longitudinal cross-sectional view of an alternate form of the shaft;

FIGURE 4 is a longitudinal cross-sectional view of still another form of the shaft in accordance with the in vention.

Referring now to the drawing, the golf club of FIG- URE 1 is seen to include an elongated tapered shaft A having a driving head B rigidly attached to its small or lower end, and a gripping handle C rigidly attached to its large or upper end. The shaft A is hollow and is filled with a quantity of foamed plastic material D.

In each of its forms as shown in FIGURES 2-4, inclusive, the shaft A has an exterior surf-ace 11 whose shape corresponds rather precisely to a truncated cone. The shaft A has a substantially uniform wall thickness throughout its length, except for a particular portion of its length in which the wall thickness is reduced.

At the lower or small end of the shaft the interior Wall surface 15 is both concentric to and parallel with the exterior surface 11. During a portion of the shaft length the wall thickness gradually reduces, the interior Wall surface 16 during this portion of the shaft length being concern tric to the exterior surface 11 but not parallel thereto. At the point of minimum wall thickness the interior wall surface 17 is both concentric to and parallel with the exterior surface 11. During the next portion of the shaft length the wall thickness increases, the interior surface being designed as 18. At 19 the interior surface is again parallel with the exterior surface, and normal wall thickness has been resumed.

It will be seen that in FIGURE 2 the diminished wall thickness occupies only a small portion of the shaft length, immediately above the driving head B. In FIGURE 3 the diminished wall thickness also commences above the driving head B and extends about twice as for, although by no means the entire length of the shaft. In FIGURE 4 the diminished wall thickness extends substantially the entire distance between the inner extremities of the driving head B and gripping handle, C.

The reason for the different lengths of the flex point of the shaft,,as shown in FIGURES 2-4, is to accommodate the needs of different players. Thus the short flex point shown in FIGURE 2 is adapted to a professional golfer having a powerful driving stroke, while the long flex point illustrated in FIGURE 4 is adapted to the average lady golfer.

In the embodiments of the invention as illustrated herein, the shaft A is integrally formed of aluminum with a basic wall thickness of 0.050 inch. Where the wall thickness is reduced its minimum value is 0.030 inch. Both the exterior and interior surfaces of the shaft are made smoothly continuous throughout the shaft length so as to provide a gradual wall thickness change at each end of the reduced wall thickness portion.

In assembling the complete golf club of FIGURE 1 the interior of the shaft is filled with foamed plastic material. A fraction of an ounce of solid plastic material is placed inside the hollow shaft, two or three drops of liquid catalyst are added, and the plastic material then foams up so as to fi-ll the entire shaft interior. Thereafter the open end of the shaft is closed by attaching the gripping handle C. If the plastic filler were not used the performance of the club would be adversely affected by vibrations in the shaft, and on striking the ball there would be an abnormal hollow sound. However, the plastic filler eliminates the hollow sound; the user may not even know that his club has a hollow shaft, and the mechanical vibrations induced by swinging the shaft are dissipated without adverse effect.

The invention has been described in considerable detain in order to comply with the patent laws by providing a full public disclosure of at least one of its forms. However, such detailed descripjtion is not intended in any way to limit the broad features or principles of the invention, or the scope of patent monopoly to be granted.

I claim:

1. A long-handled-swingable driving instrument comprising an elongated integrally formed hollow metal shaft; gripping means affixed to one end of said shaft; and a driving head affixed to the other end of said shaft; said shaft having a substantially uniform wall thickness throughout its length except for a portion of its length in which the wall thickness is reduced, the exterior and interior surfaces of said shaft being smoothly continuous and providing a gradual wall thickness change at each end of said reduced thickness portion; whereby during swinging of said instrument the maximum flexing of said shaft occurs in said reduced wall thickness portion there of.

2. A driving instrument as claimed in claim 1 in which the interior of said shaft contains a quantity of foamed plastic material.

3. A golf club shaft comprising an elongated metal tube having a relatively largediameter upper end adapted for attachment of hand-gripping means thereto and a relatively small-diameter lower end adapted for attachment of a golf club head thereto, said shaft being of tapering diameter throughout its length and having a substantially uniform wall thickness at both its ends, a portion of the mid-section of said shaft having a reduced wall thickness whereby the maximum bending of said shaft occurs in said reduced-wall-thickncss portion thereof rather than in the minimum diameter portion at the lower end of said shaft, the shaft outer surface corresponding rather precisely to a truncated cone while the shaft inner surface is smoothly curved throughout the length of said reduced-wall-thickness portion.

4. An instrument as claimed in claim 1 wherein said metal is aluminum.

5. A golf club shaft as claimed in claim 3 wherein said metal is aluminum.

References Cited in the file of this patent UNITED STATES PATENTS 2,085,915 MaCCalhlrn July 6, 1937 FOREIGN PATENTS 465,414- Great Britain May 5, 1937

Claims

1. A LONG-HANDLED-SWINGABLE DRIVING INSTRUMENT COMPRISING AN ELONGATED INTEGRALLY FORMED HOLLOW METAL SHAFT; GRIPPING MEANS AFFIXED TO ONE END OF SAID SHAFT; AND A DRIVING HEAD AFFIXED TO THE OTHER END OF SAID SHAFT; SAID SHAFT HAVING A SUBSTANTIALLY UNIFORM WALL THICKNESS THROUGHOUT ITS LENGTH EXCEPT FOR A PORTION OF ITS LENGTH IN WHICH THE WALL THICKNESS IS REDUCED, THE EXTERIOR AND INTERIOR SURFACES OF SAID SHAFT BEING SMOOTHLY CONTINUOUS AND PROVIDING A GRADUAL WALL THICKNESS CHANGE AT EACH END OF SAID REDUCED THICKNESS PORTION; WHEREBY DURING SWINGING OF SAID INSTRUMENT THE MAXIMUM FLEXING OF SAID SHAFT OCCURS IN SAID REDUCED WALL THICKNESS PORTION THEREOF.