US 1713812 A
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y 1929. G. E. BARNHART 1,713,812
METHOD OF MAKING GOLF CLUB SHAFTS Filed Dec. 13 1926 I l I Callborujea bfare Woe ur e Z. 30 )wAar-Z 4 TTOQNEY Patented May 21, 19 29 umrsn STATES PATENT OFFICE.
GEORGE E. B RNHAR T; or PASADENA, CALIFORNIA.
METHOD OF MAKING GOLF-CLUB SHAFTS.
Application filed December 13, 1928 Serial No. 154,468.
Although my present invention is entitled as relating more particularly to the shafts or handles of golf clubs, it should be understood that this invention may be regarded. as
other shaping of the same by swaging dies;
but Ihave discovered. that very superior results may be obtained if a taper-drawing 20 or a taper drawing and rolling operation, or
the like, is conducted subsequently to a carb'onization. One notable effect of this sequence of operations is the compacting of a metallic wall of the article incidentally to the production and/or concentration of fiber therein, in such manner as to obviate any tendency toward spongine'ss in the final product, and the crystalline structure of the high carbon case or skin formed upon the metal is drawn down or so drawn and rolled as to be compacted into the main body of the metal in a manner favorable both to the appearance of the finished product and to the toughness and/or resiliency of the same.
Aiming at the production of golf club shafts and /or other structural elements from comparatively inexpensive seamless or jseam tubing purchased under a specification prescribing a low carbon content thereof, I find that, by proceeding in the novel manner above referred to, carbonizing before drawing, IIcan produce golf club shafts of high quality. Using my method, even socalled steam tubing-such as may be produced, by bending and welding, from a sheet metal, or otherwise obtained at a very moderate cost, makes very satisfactory articles; and my invention may accordingly be regarded as relating to the production high quality structural elements from either seamless or seam tubing, having the proper carbon or alloy content before drawing, the seam tubing being entirely satisfactory for most uses, although much less expensive; and, as hereinafter described, my invention may also be regardedas relating to drawn struc-' i'indicated bythe line 22 of Fig. 1,-this in Fig. 1.
.respectively to Figs. 1, 2 an 3, but suggesting tural elements pr0ducib1e by the mentioned stages, and more particularly to units which are not only tapered but provided with walls of uniform thickness or with walls which are thlckest in a region of minimum outside di- .ameter.
Where seam tube is used, alloy 01' special carbonstcel may be usedsaid alloy containmg metals such as vanadium, nickel or molybzlentum, together with the desired carbon conen A Other objects of my invention may be best appreciated from the following description of an illustrative embodiment thereof, taken in connection with the appended claims and the accompanying drawings, in which Fig. 1 is intended merely to represent, in elevation, a part of a seamless tubular unit or stock suitable for use in the production of golf club shafts or other structural units, by
my novel process.
Fig. 2 is a cross'sectional view which may be regarded as taken in such a plane as that :view being however; intended primarily to symbolize, by a showing of small approximate circles withina wall area, the effects of a carbonization of a tube such as is shown Fig. 3 is a-view comparable to Fig. 2, but intended to symbolize the effects of a drawing subsequent to a carboniza'tion,-the crystal or grain structure of the metal being here represented as smaller and a production of fiber by drawing, and the change in the physical characters, being suggested by minute crosses or Xs.
Figs. 4, 5 and 6 are views-corresponding the use of a so-called seam tubing, rather than seamless stock, in the production of a structural unit by steps including a carbonization and a subsequent drawing.
Fig. 7 is a View showing a structural unit within my invention as embodied in'a golf club,walls of said unit being substantially uniform in'thickness and parts being broken Referring to the details of that specific embodiment of my invention chosen for purposes of illustration, a seamless tubing 11 or a seamltubing 11' (see Figs. 1 and 4) (with an incidental increase in the thickness and crystallization in the walls vthereof). During the carbonization a granular or crystallized condition tends to be developed in the exposed surfaces of the tube, somewhat as indicated (with diagrammatic exaggeration) at 12, 12 in Figs. 2 and 5. a
Subsequently to the mentioned carbomzation (in which it should be understood that an alloy steel, such as a low carbon steel containing nickel, vanadium, or molybdenum, or the like, may be employed) I sub ect the mentioned tubes to a drawing or to a' combined rolling and drawing operation, preferably producing a taperthis drawing being so executed as to effect an incidental compacting of the hard outer case of carbonized metal with the soft inner core of low carbon metal, at the same time producing an elongation of fibers therein,son1ewhat as suggested by Xs at 13 and 13, Figs. 3 and 6, and de creasing the size of the grain or crystal formation somewhat as diagrammatically indicated at 12 and 12 The figures last mentioned,may be regarded as corresponding approximately to cross sections taken respectively as indicated by the line 33 of Fig. 7
' and by the line 6'6 of Fig. 8.
' As illustrated in Fig. 7, in case a structural unit, formed in the general manner indicated, is intended for use as a golf club shaft 14, it ma have a substantially uniform wall, even t ough it be provided with a constriction 15 having a downwardly-tapered head-carrying enlargement 16 therebelow; and a head or plate 17, provided with a cooperating socket element 18, may be secured thereto by means such as a mere drive fit and/or a transverse rivet or tapered pin 19; but I also show, in Fig. 8, a structural unit in the form of a golf club shaft 14', which is formed from a stock having a longitudinal seam 20 (which may have been formed, in advance ofthe described operations, by autogenous welding or the like); and, although this structural unit may have the same external configurationas that illustrated in Fig. 7, and either the same or a different alloy composition and fibrous structure resulting from carboniza-.
tion before drawing, said drawing must be understood to have been so executed as to ter; and said drawin or rolling and drawing operation may also be so executed as to produce a downward thinning of a downwardlydiminishing portion adapted to fit within a socket 18, shown as retained by a taper r pin 19',
It should be understood that structural units formed in the described general manner may be either thickest or thinnest in a region of minimum outside diameter, or of substantially uniform wall thickness throughout; and that units formed in the described manner may be used for any desired structural-or other purpose,my description of thesteps of my process as applied to the production of golf club shafts being merely illustrative; and although, for the sake of completeness, I show the shaft 14 as provided not only with a head or plate 17 but with an external grip 21, and also with a cap'button 22 constituting a closure at the upper end thereof (either or both of the last mentioned elements being advantageously formed from a composition such as bakelite and/or from a wrapping of fabric impregnated with such a composition) the features last referred to may be regarded as immaterial to my described method of producing metallic structural units.
Although I have herein described alternative embodiments of my invention, it should be understood not only that the stages set forth may be used in the production of hoe handles, masts or the like, but that various features thereof may be independently employed and also that additional modifications might be devised, by those skilled in the arts to which this case relates, without involving the slightest departure from the spirit and scope of my invention, as the same is indicated above and in the following claims,- in which the term drawing should be understood as including those operations in which a drawing action is accomplished by means which have also a rolling effect.
I claim as my invention:
A method of producing a metallic shaft which comprises: carbonizing a suitable steel tube; and subsequently subjecting the same to operations which include a drawing and a consequent production of fiber concentration in a region having a diminished diameter,
In testimonyv whereof, I have hereunto set my hand at Los Angeles, California, thisfith day of December, 1926.
' GEORGE E. BARNHART.