Grip for sport clubs
US 2704668 A
Description (OCR text may contain errors)
March 22, 1955-' T. S. PARK, SR
GRIP FOR SPORT CLUBS 2 Sheets-Smm l Filed Aug. 22, 1949 Gttomeg March 22, 1955 T. s. PARK, sR
GRIP FOR sPoRT cLuBs 2 Sheets-Shee. 2
Filed Aug. 22, 1949 Gttorneg United States Patent O GRIP FOR SPORT CLUBS Tracy S. Park, Sr., Houston, Tex., assignor to Tracy S. Park, Jr., Bellaire, Tex.
Application August 22, 1949, Serial No. 111,698
3 Claims. (Cl. 273-81) This invention relates to improvements in the construction of sport clubs and particularly golf clubs, and is more particularly directed to improvements in the construction and mounting of the hand-gripping portion of such sport clubs and golf clubs.
This invention is an improvement upon the invention described, disclosed, and claimed in my Patent No. 2,115,119, issued April 26, 1938.
The hand-gripping section of sport clubs, such as golf clubs, tennis rackets, baseball bats, fishing rods, lacrosse bats, hockey sticks, all have the feature in common that it is desirable that the gripping surface have a high frictional resistance in the hands, even though they should be wet, as they may be due to immersion in water or due to perspiration. In clubs such as tennis rackets and golf clubs, baseball bats and hockey sticks it is also desirable that the grip be somewhat resilient so that part of the shock of impact may be taken up in the grip and not be transmitted entirely to the hands. This is particularly true in the case of golf clubs.
As is well known to players of golf, it is highly important, in order to obtain a proper swing, that the relationship of the club to the fingers during the back swing and the forward swing and follow through remain unaltered. Any relative movement of the club in respect to the hands as a result of any slippage between the fingers will impair the perfection of the swing and produce unsatisfactory results. It is therefore particularly important that the golf grip surface be highly frietional in character, so that there be no tendency for the golf club to slip in the hand even though it be Wet as it often is from perspiration.
While it is advantageous that the golf club grip have some resilience so that the impact of the club base against the ball be not transmitted as shock to the wrists, there is another aspect of this property which is of extreme importance and which has not been achieved in the prior art clubs; it is that somewhat intangible property known as feel.a For proper back swing and follow through, it is recommended that the club be gripped with the thumb of the right hand and the index and second fingers of the right hand in the proper gripping position. This permits of snap through when the club head swings in the forward swing and follow through occurs. The degree of pressure generated by the lingers on a club grip is known as feel Many players find that with a hard, substantially nonresilient grip, the control of the pressure and its adjustment is diliicult to obtain. Many players prefer a hard but still somewhat resilient grip.
The rubber fabric grip described in my said aforementioned patent has been highly successful in presenting a non-slipping surface, and due to the fact that the rubber has some little resilience when molded and positioned on the club head, some degree of feel is obtained.
I have devised a new grip for such clubs which is particularly useful in the case of golf clubs in which the surface of the grip is provided with finger-locating sections whereby the proper and desirable grip is obtained by placing the lingers in the spaces provided on the surface of the grip.
In one form of my new sport club grip particularly useful for golf clubs the feel is enhanced by stretching that portion of the golf club grip which is encompassed by the ngers in their normal golf club gripping ICC position for play. I am, however, also able to modify the resilience so as to obtain different degrees of resilience to satisfy the idiosyncrasies of the players who desire a harder grip. This is accomplished by molding a sleeve of rubber or other elastomer. The sleeve is then positioned upon the sport club, as, for example, the golf club shaft in such manner as to locally distort portions of the sleeve to increase the diameter of the outer surface at localized portions on the outer surface spaced in a direction longitudinal of the sport club, so as to place such portions under tension. This is accomplished by forming such localized portions of the grip with an internal diameter less than the diameter of the sport club at such portions when the golf club is in position. The golf club then distends or puts a radial pressure upon the grip at such portion, causing the rubber sleeve to stretch and increase in its outer diameter at such localized portion and placing the rubber in tension at such portion. The rubber under tension feels as though it is more resilient than the rubber which is under compression or is not stressed. The stressed portion is thus increased in resilience while the unstressed portion has a lesser resilient feel of the original rubber.
Another advantage of this procedure and of the grip thus formed is that the distended rubber grips the golf club strongly and thus permits of an improved bonding of the golf club to the grip. I may also employ the invention of my said Patent No. 2,115,119 to cause the outer surface of the grip to have positioned thereon in longitudinal lines spaced around the circumference of the outer surface cord or fabric to give alternate but parallel fabric and rubber lines.
I have thus devised a golf grip sleeve formed of rubber or other elastomer which may, if desired, have fabric lines on its surface, having a conical outer surface and protuberances positioned on the inner surface and having local areas of lesser internal diameter than the diameter of said sleeve, said protuberances being spaced longitudinally of said sleeve, and these may be formed with grooves on the exterior of the sleeve. In one form the said grooves are spaced to be opposite the said protuberances and in another form between said protuberances. When such sleeves are positioned on the golf club, the portions of the golf grip adjacent the protuberances form convex bulges on the exterior of the golf club grip.
These and other objects of my invention will appear more clearly from the further description thereof taken together with the drawing, in which Fig. 1 shows one form of the grip positioned upon a golf club;
Fig. 2 is a section showing the position of one form of the grip in its mold when being manufactured;
Fig. 3 is a fragmentary partial section of the grip shown in Fig. 2 after removal from the mold;
Fig. 4 is a magnified section of the surface of the golf grip of Fig. 3; t
Fig. 5 is a fragmentary section taken on line 5-5 of Fig. 4;
Fig. 6 is a partial section of the golf grip of Fig. 3 installed upon a golf club;
Fig. 7 is a section showing the position of another form of the grip in the mold when being manufactured;
Fig. 8 is a fragmentary section of the grip shown in Fig. 7; and
Fig. 9 shows the form of grip of Figs. 7 and 8 mounted on a golf club.
First describing the form of grip shown in Figs. l-6, inclusive; a split mold 1 having a conical interior 3, preferably one in which the inner periphery at any sectional plane is circular and formed with circumferential ridges 2 spaced apart at a distance of about or, to wit, the distance between the fingers of a normal hand, is employed in forming the grip of my invention. While I have shown the ridges 2 as circumferential they may be positioned spirally at a pitch equal to about said finger spacing. I prefer, however, to use the circumferential ridges correspondingly spaced.
An internal mandrel 9 is provided of generally conical nature corresponding in slope to the slope of the inner surface 5 of the mold and has spaced ridges 10. The mandrel between the ridges is concave, as shown at 11, and conical at its end 9a.
A woven or knit tube of fabric is slipped over the mandrel 9 to t snugly thereover. A trapezoidal sheet of uncured rubber 8 is then placed over the fabrlc tube and the longitudinal edges abutted over the mandrel so as to form a cone of uncured rubber over the mandrel. The rubber cone is then covered by fabric. Various fabrics as indicated may be used. If a knit tube is employed it is slipped over the rubber so as to hug the outer conical surface throughout its longitudinal length; or if a fabric strip is employed it is cut into a trapezoidal shape and positioned over the rubber so as to form a conical fabric layer conforming to the shape of the rubber cone. Thus, for example, I may employ the fabric referred to in my said Patent No. 2,115,119. It is convenient to coat the side of the fabric which is to overlie the rubber with a rubber cement to assist in the final molding operation.
I prefer to employ a fabric so woven or knit that there are cord or yarn portions which align themselves in longitudinal lines, there being a depression or space between the said longitudinal lines into which the rubber may protrude, as will be described below. Many forms of fabric can be made which give this result. Thus, a fabric composed of relatively closely spaced cord or yarn with widely separated and sparsely arranged Woof or fill of much finer cord or yarn. Such fabric is used in forming tires and is illustrated as one of the forms of fabric which may be employed in said Patent No. 2,115,119. The fabric is arranged so that the cords run longitudinally of the grip. If a ribbed knit fabric is employed, the fabric is arranged so that the ribs run longitudinally of the grip and the spaces between the ribs, being depressed below the ribs, are filled with and covered by rubber to give longitudinal lines of cord, i. e., yarn, as will be further described below.
The mandrel is then placed in one half of the mold so that the ridges 10 and 2, whether spiral or circumferential, are preferably positioned opposite each other. When the split mold is assembled over the mandrel and the ends closed by the end closures 6 and 7 and subjected to heat and pressure, the rubber sheet is cemented together at its edges and the fabric is fused to the surface of the rubber; and the rubber conforms to the mold and the mandrel, forming convex protuberances circumferentially of the inner surface of said rubber sleeve 13 of the radius of curvature of the concave portion 11 of the mandrel and spaced at equal intervals longitudinally of said sleeve, and with a concave portion 12 positioned between the convex portions corresponding to the radius of curvature of the convex ridge 10. The radius of curvature of the convex portion 13 of the grip is greater than the radius of curvature of the concave portion 12.
The outer surface of the molded grip is conical at 14 corresponding to the slope of the conical portion 5 of the mold, and with an outer periphery at any section which is circular and has a concave circular depression 15 corresponding to the circular ridge 2 of the mold. If the ridges are spiral the depression 15 will be spiral. The preferred form is to use circular ridges 2 to form circular depressions 15. The concave portion 12 and the depression 15 are positioned opposite each other. These provide for a thickness of rubber which is less than the thickness of rubber between the convex portion 13 and the outer surface 14 of the rubber sleeve. It will be observed that as illustrated the grooves 12 are between the convex portion 13 and these convex portions are thus spaced longitudinally of the sleeve at the interval of said grooves 12.
The mold is then separated and the mandrel and the molded sleeve removed from the mold. The sleeve may then be stripped from the mandrel, the convex portion 13 distending to permit the ridges 12 to pass through the sleeve. The resultant sleeve is shown in Fig. 3 and it will be seen that it has an exterior smooth conical surface 14 equal to the conical surface 5 and the interior convex portion 13 alternating with the concave portion 12. The internal diameter of the sleeve of the convex portion 13 is less than that of the concave portion 12. The fabric 2 is cemented and glazed over with the rubber due to the molding operation, and this is equally tjue for the fabric 16' positioned on the exterior of the s eeve.
The overow rubber at the seam is trimmed by grinding the seam smooth. The exterior glaze of rubber is removed by a grinding operation. This is conveniently done by placing the molded rubber grip, after the excess rubber present at the seam has been removed, onto a mandrel which is rotated by a motor at high speed. A piece of emery cloth is then held against the rotating surface and advanced longitudinally of the rotating grip. By regulating the degree of pressure and the number of passes the amount of rubber and fabric removed may be controlled. I prefer merely to abrade the outer surface of the grip sufficiently to remove the glaze over the fabric, produce a smooth conical surface, and to roughen the fabric material. I do not desire to cause the fabric to stand above the rubber surface in ridges or to cause the rubber to stand in ridges above the fabric. The generally conical outer surface of the molded grip before grinding makes for easy and uniform removal of the outer surface to give a relatively smooth outer conical surface interrupted by the circumferential groove 15 or similar spiral grooves, if such are used.
In this manner the outer layer of glazing rubber is removed and a portion of the fabric is ground away to reveal fabric arranged in longitudinal lines, as shown at 16, between which are positioned lines of rubber at the surface of which substantially no fabric is present. By grinding away a portion of the cord as well, any tilamentary material employed in constructing material, that is, yarn or twine or whatever other equivalent filamentary used in forming the fabric will be roughened to improve the gripping action. If the twine, cord or yarn is twisted, the surface of the cord or yarn will appear to consist of a series of short cord portions illustrated at 17', all lying parallel and aligning themselves in the longitudinal line 17. Other patterns defining the fabric lines will be obtained, depending on the nature of the cord or yarn and the weave or knit pattern employed.
The surface of the grip is generally smooth in that the surface of the rubber and the exterior surface of the cord are upon substantially the same surface. The fabric does not protrude above the rubber to give ridges. The portion of the grip in the depression 1S formed by the circular or spiral groove will generally not be ground away.
The molding of the rubber so that the surface 14 is conical permits of the abrasion action to reach all portions of the surfaces between the depressions 15. The interior of the grip has the convex portion 13 formed by the concave depressions 11 of the mandrel intermediate the concave grooves or depressions 12 formed by the ridges 10 of the mandrel which are opposite the grooves 15 on the exterior of the sleeve formed by the ridges 2 of the mold. The thickened portions are reduced or necked down at their ends to form the grooves 12 and 15.
The sleeve may then be mounted upon the sport club, as, for example, a golf club, in the usual manner by using the usual rubber cement which is now generally employed in mounting rubber golf grips on golf clubs. The club is pushed through the sleeve into position. Since the external diameter of the golf club is larger than the internal diameter of the sleeve at the convex portions 13 and approximates the internal diameter of the sleeve at the concave portions 12, the distension of the rubber at the portions 13 occurs with substantially none or only minor distension at the portions 12. The rubber cement is squeezed out between the surface 13 and the surface of the club forming a thin film of cement with a thicker film of cement at the positions 12 where there is substantially none or only minor distension. The shaft is thus gripped strongly at 13 and cemented in place with thicker cement portions appearing at 23 at the position of concavities 12.
It will be observed that the distension of the convex portions 13 causes the portion 14 to bulge out as shown at 21, and this occurs at each convex portion 13 so that the resultant golf grip is in the form of a series of circumferential protuberances having generally the shape of the surface of a torus, although the exact form of the curve is not as important as that there shall be annular rings of rubber, preferably convex, which are radially distorted and in tension with alternating con cave portions between the convex portions. The intermediate grooves 12 need not be in tension and preferably are under little or no tension, so that the rubber may be distorted and tensioned at the convex portions as indicated, and separated by concave grooves 20 positioned in the concave portions. The grooves are positioned at the portion corresponding to portion 15 in the molded structure as shown in Fig. 3.
The portions 21 are spaced apart, as described above, in such manner that when gripped each linger of the hand is on one of the bulges 21. The bulges 21 are under radial tension resulting in an increased resilience and the feel to which reference has been made.
The form shown in Figs. 7-9 is formed by displacing the mandrel one-half the distance between the ridges in the mold so that the ridges in the mandrel instead of being opposite the ridges in the mold are between the said ridges. The parts corresponding to the parts shown in Figs. 1-6, inclusive, appearing in Figs. 7-9 bear an additional prime number.
The split mold 1 is the same as mold 1 and the mandrel 9 is the same construction as 9, having a conical end portion 9'a and spaced ridges 10 and concave sections 11.
The rubber and fabric or other textile material described in connection with the previous form are placed on the mandrel in the same manner as described above. The rubber covered mandrel is placed on the mold with the concave portion 12', corresponding to 12, being positioned between the ridges 2 and equally spaced therefrom instead of opposite the ridges 2 as in the previous form. The mandrel is closed and the rubber cured as before. The cured rubber sleeve on the mandrel again conforms to the mold and mandrel, forming convex protuberances 13 on the inner surface of the sleeve of the radius of curvature of the concave portion 11 of the mandrel and spaced at equal intervals longitudinally of the sleeve and with concave portions 12 corresponding to the radius of curvature of the convex ridges As described in connection with the previous form the radius of curvature of the convex portion 13 is greater than the radius of curvature of the concave portion 12'. The outer surface of the molded grip is conical corresponding in slope to the conical inner surface 5 of the mold 1' with a circular peripheral section. It has a conical circular depression 15' corresponding to the ridge 2". As previously stated for the previous form, if the ridge is spiral, the depression 15 is spiral.
I prefer, as previously, to employ circular ridges 2" to form circular grooves 15'. The ridge 2" is positioned centrally of the concave portion 11 and intermediate between the ridges 10. This is the only substantial diiference between the two forms of molded sleeves. Externally they appear substantially the same, and internally the convex and concave portions are displaced longitudinally, as compared with the form of Figs. 2 to 6, inclusive, one-half the interval between the circular ridges on the mold surface.
The sleeves are finished in exactly the same manner as in the case of the form of Figs. 2-6, inclusive, and are mounted on the club in the same manner. When mounted on the club a substantially different configuration of the external surface of the grip is obtained, as is illustrated in Fig. 9.
It will be observed that the grooves 15' are at the crown of the convex portions instead of in the concave portion between the crown of the adjacent convex portions, and the position of the grip between the grooves instead of being circumferential and convex are circumferential and concave. The convex portions 21 have circumferential grooves 20' positioned at the crown of the bulge, as described above. Between the grooves are concave portions 21a which thus form the finger receiving grooves instead of the bulges 21 of the previous form. Each of these grooves is spaced as described above at the normal finger spacing determined by the spacing of the grooves 12 and 2".
The exterior surface of the grip in both forms is, as described above, composed of longitudinal lines formed of the aligned cord portions each separated by parallel lines of revealed rubber, with substantially no rubber glazing over the abraded surface of the fabric. This cord formulation is obtainable by various expedients which have been used in the practice and may be also employed in the construction of this grip. Thus, basket weave or stockinette material or fabric material such as illustrated in my said Patent No. 2,115,119 may be employed. Other types of fabric formed of cord, yarn, twine, thread or other textile filaments formed of cotton, wool or synthetic plastics or other equivalent textile material may be employed for such purpose, as will be understood by those skilled in the art.
The surface is a slip-resistant surface due to the fabric exterior and to the fact that rubber lines are positioned between fabric lines with few, if any, fabric lines at the surface crossing the rubber lines or circumferentially of the grip. The exterior is, however, smooth so that the grip, being non-slip, is not rough and will not injure the players hands when gripped.
While I have described a particular embodiment of my invention for the purpose of illustration, it should be understood that various modifications and adaptations thereof may be made within the spirit of the invention as set forth in the appended claims.
1. A sports club grip suitable for installation on a sport club shaft which comprises a hollow rubber sleeve having alternate thick and thin portions along its length, the thick portions comprising, when viewed in longitudinal cross-section of the sleeve, protuberances within the interior of the sleeve, the thin portions being the necked down ends of the thick portions, the structure being such that on applying the sleeve to a shaft having a diameter larger than the inner diameter of the sleeve the protuberances are, due to the necked down portions, exed outwardly and the outer surface of the sleeve opposite the protuberances becomes tensioned; the thick portions of said sleeve being approximately the average finger width of a user.
2. The grip of claim l wherein the thick and thin portions are arranged circularly around the sleeve.
3. The grip of claim 1 wherein the thin portions have an inside diameter such that on application to a shaft small channels are formed between the sleeve and the shaft at such thin portions.
References Cited in the ile of this patent UNITED STATES PATENTS 631,648 Lockwood Aug. 22, 1899 1,638,454 Papin Aug. 9, 1927 2,115,119 Park Apr. 26, 1938 2,171,382 Wettlaufer Aug. 29, 1939 FOREIGN PATENTS 17,338 Great Britain 1909