US2078728A - Rebound check for golf club shafts - Google Patents

Description

4 Lard April 27, 1937. A. E. LARD REBOUND CHECK FOR GOLF CLUB SHAFTS Filed Nov. 30, 1936 Patented Apr. 27, 1937 REISSUED UITED STATES PATET OFFICE REBOUND CHECK FOR GOLF CLUB SHAFTS Allan E. Lard, Washington, D. 0.

Application November 30, 1936, Serial No. 113,510

13 Claims. (Cl. 273-80) This invention relates to tubular steel-shafted 20 inches from the small end of the shaft. The golf clubs, and particularly to clubs of the irons dowel may be made tapered and then slitted as type. It is a well known fact that steel-shafted indicated at i in Figures 2 and 3, with a thin irons tend to impart to the fingers, upon imslitting saw, for example one .009 inch thick, to

5 pact with the ball, an unpleasant or stinging senwithin 2 inches of the small end, the dowel being 5 sation which is not present in the hickory shaft. trued up circularly, or it may be made of two This undesirable feature in the steel shaft is due half-round inch sections 15 and 16, as shown to the excess speed of the rebound or reaction in Figure 5, the head ends of which are glued Vibration of the steel shaft over hickory, and partogether for a distance of about 2 inches as at l I ticularly to the first rebound after impact of the and then turned to fit in the internal wall, the 10 blade with the ball. Said impact flexes the steel half-rounds being pinned together to facilitate shaft backwardly and an almost instantaneous rethe turning operation, said pins being subsequentj bound occurs, and it is the force and speed of this ly withdrawn.

rebound or its re-action rebound or rebounds By either method of construction the dowel is l5 that cause the aforesaid unpleasant or stinging formed approximately 20 inches long having two sensation. prongs 5 and 6, 18 inches long extending up from The main object of this invention is to eliminthe small end, both prongs having opposing flat ate this objectionable feature in the steel golf faces which bear on each other and have a relashaft. tively sliding movement under the fiexure and In the drawing which accompanies and forms rebound of impact. 20 a part of the following specification and through- About one inch from the upper end of one of out the several figures of which the same charthe prongs, of either construction, for example acters of reference have been employed to desthe prong 6 in Figure 2, is sawed 01? with a saw ignate identical parts, 1 of an inch in width and the sawed-off section Figure 1 is a view in elevation of the front side I is glued to the opposite prong, in its original 25 of a steel golf club. relation to the same, and additionally secured Figure 2 is a longitudinal section through the with tight-fitting wood pegs 8 dipped in glue. shaft showing the vibration absorbing member There is now a space of 1 inch (width of the in its maximum state of displacement, the shaft saw) between the end of the short prong 6 and p. being in rectilinear position, said member being its sawed-off section 1. A rubber half-disk 9 30 slit. is provided, about inch thick in its relaxed t Figure 3 is a similar view to Figure 2 the lower state. The dowel is flexed backwardly to the expart being omitted and the shaft being shown in tent of the maximum fiexure of a full shot and it the flexed position upon impact with the ball is preferably steamed and set in this bowed posishowing the rubber vibration absorber in relaxed tion. The backward flexing of the dowel in- 5 position. creas the t; inch wide space or slot to about Figure 4 is a cross section taken along the line inch in width by the relative sliding movement 4-4 of Figure 2. which takes place between the flat abutting sur- Figure 5 is a longitudinal section showing a faces of the prongs 5 and E5. The rubber half- .40 modified form of dowel, made from two half disk is inserted in said space or slot while the round sections. latter is thus spread, the thickness of the rubber Figure 6 is a cross section taken along the line being about the same width as the slot while the 6-5 of Figure 5. latter is in extended position. The diameter of Figure 7 is a cross section through a modified the rubber half-disk 9 is made slightly less than .45 form of vibration absorber, and the diameter of the half-round end of the short Figure 8 is a plan View of the same. prong 6 to provide room for the displacement of Referring now in detail to the several figures, the rubber half-disk as shown at 9a in Figure 3.

the numeral i represents in general a tubular In that form of the invention shown in Figures tapered steel golf shaft, about 36 inches long, of 5 and 6, the two half-round sections of the dowel .50 the usual type having a midiron 2 attached theremay be hollowed out as indicated at H) to within to. A light wooden dowel 3 preferably of pine about 2 inches of the top. This reduces the and about 20 inches long is turned to fit the inweight. When two halves are employed the ho1- ternal wall of the shaft l, a slight tolerance belowing is a fast manufacturing operation. ing left for a purpose hereinafter described, the In either form of the invention, the split dowel .55 dowel extending for a distance of approximately is inserted in the tubular steel shaft with the convex side of the half-disk 8 toward the front and it is pushed into the shaft so as to make a snug fit with the inner Wall of the shaft, but not so tight as to prevent-the abutting faces of the split from sliding-relative to one another. The dowel preferably terminates at the end of the shaft and is retained in place by a circumferential crimp l9 pressed into the shaft and entering the wood. After the dowel has been steamed and set in bowed shape as described it acquires an inherent stress when forced into the shaft which provides an additional resistance to the rebound. The shaft is inserted in the hosel of the head 2 in such a manner that the rubber half-disk faces in the direction of that side of the head which contacts the ball, and is pinned with the usual rivet II. Since, at the time the assemblers receive the tubular shaft the dowel is concealed therein,it is essential that the shaft'be marked in some way so that the shaft can be secured to the head in proper relation with respect to the front or disk side and the striking face. The front or disk side may be readily indicated by a V-notch 52, Figure 1, or other suitable index, filed in the upper end of the shaft, the leather grip being partly removed to show the same.

Upon impact with the ball the shaft is flexed backwardly as in Figure 3 and an almost instantaneous rebound occurs as before stated. This rebound is checked by the end l3 of the short prong 5 with its piston-like action, moving against the rubber half-disk and forcing said disk into its displaced position against a thin rubber sock l8 drawn over the dowel to prevent the same rattling against the wall of the shaft in the event the dowel should shrink. This rubber sock also provides rubber which can be displaced. The normal length of the sock is about 10 inches and is stretched to cover the length of the entire dowel. When the shaft on its first rebound attains its normal straight position, the rubber half-disk is flush with the outside surface of the dowel and therefore pressing against the sock l8. Rubber, while displaceable under pressure, is incompressible, so that whatever rebound is still in the shaft in excess of that which was checked by the resistance of the rubber half-disk to displacement, is now further checked by the displacement of the sock l8 in contact with the half-disk. All rebounds, reactions or vibrations after impact are, therefore checked, thus reducing or nullifying the former vibrations of the steel shaft.

Figures 7 and 8 show that instead of employing a solid piece of rubber for the half-disk, I may substitute a cloth covered rubber bag It filled with air, preferably slightly compressed and sealed. The end thrust of the short prong 6 compresses the air in the bag and thus checks the rebounds of the shaft in play, the internal wall of the shaft and the slot l3 forming a container for said bag.

As has been previously stated, the Wooden dowel should be inserted firmly in place in the steel shaft, but not with sufficient pressure to prevent the flat faces of the split dowel from sliding against one another.

The present invention does not confine the construction of the dowel to wood. I may employ any suitable composition material or metal, such as aluminum. Neither is it essential that the shaft be tapered for if desired, a shaft and dowel that are not tapered may be employed.

While I have in the above disclosure described What I believe to be the preferred and practical forms of my invention, it will be understood to acting to check the rebounds of said golf shaft in play, said split member being provided with a recess expansible in width under fiexion of said member and flexed backwardly to receive said rubber bumper.

2. In a golf club, a tubular steel golf shaft, a

, split member inserted in said shaft, said member having two prongs having relative sliding,

movement under fiexions of said shaft, a rubber bumper between said prongs, said prongs coacting through the intermediary of said bumper to check the rebounds of said shaft in play.

3. In a golf club, a tubular steel golf shaft, a split member inserted in said shaft, one of the parts of said member defined by said split comprising a prong with a piston-like movement relative to the other part of said member, a resisting rubber element between the parts of said split member and Which the end portion of said prong impacts, acting to check the rebounds of said shaft in play, said rubber element being provided with room for limited displacement under end pressure from said prong.

4. In a golf club, a tubular steel golf shaft, a two-piece member inserted in said shaft, one of the pieces of said member comprising a prong with a piston-like movement, a resisting rubber element which the end portion of said prong impacts acting to check the rebounds of said shaft in play, said rubber element being provided with room for limited displacement under pressure.

5. In a golf club, a tubular steel golf shaft, a two-piece member inserted in said shaft, one piece of said member constituting 2. prong with a piston-like movement, a flexible bag of air between the end of said prong and the other part of said member acting to check the rebounds of said shaft in play.

6. In a hollow resilient golf club shaft, a rebound check extending through a substantial length of said shaft and making firm contact with the surface thereof, comprising a member of circular cross section longitudinally divided by a split of no width, from a point a short distance from the end of the member adjacent the head of the club to a. point a short distance from the end of said member remote from the head of said club, and being transversely divided adjacent the end of said split remote from said head and to one side of said split, by a slot of appreciable width, the said split and slot dividing said member into long and short prongs having their proximate ends in confronting relation, and coacting as a piston and an abutment, moving within the range of the Width of said slot under variations in the relative sliding movement of said prongs produced by bound and rebound of said shaft, and a rebound checking element confined in said slot.

7. In a hollow resilient golf club shaft as claimed in claim 6, a layer of rubber between said member and the interior wall of said shaft.

8. In a hollow resilient golf club shaft as claimed in claim 6, said..member being hollow at some distance below the diametrical plane of said slot. 4

9. In a hollow resilient golf club shaft as claimed in claim 6, said rebound checking element comprising a flexible capsule filled with air.

10. In a hollow resilient golf club shaft as claimed in claim 6, the member of circular cross section being made of wood.

11. In a hollow resilient golf club shaft as claimed in claim 6, the member of circular cross section being made of wood steamed and set into a bowed shape with its convex side facing the same direction as the convex side of said rebound checking element and inserted in said shaft with its convex side facing the front of said shaft whereby an inherent rebound-resisting stress is set up in said member.

12. In a hollow resilient golf club shaft as claimed in claim 6, the member of circular cross section extending to a point adjacent the lower end of said shaft, the metal of the latter near said end being crimped circumferentially into the substance of said member for holding it in place.

13. In a hollow resilient golf club shaft as claimed in claim 6, including a rubber sock on said member forming a thin rubber layer between said member and the inner wall of said shaft, against which the rebound checking member presses in the course of its displacement, displacing the rubber of said sock.

ALLAN E. LARD.

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