Patent Application
20180304131
The present invention relates to a grip for a golf club shaft, a method for forming such grip, and a golf club shaft with such a grip formed thereon.
Golf started in the early sixteenth century in Scotland. In the early days of golf and up through the early to mid 1900's, golf putters, which are a type of golf club comprised of a shaft with an upper hand placement portion known as a grip and a lower portion which is connected to a head that strikes a golf ball, have been gripped with a simple leather wrap to offer a gripping surface for wooden shafts and, thereafter, for metal shafts. The leather wrap offered not only a gripping surface, but also provided golfers with a feel for the weight of the putter head as the leather wrap grip was lightweight, thin, and directly connected to the shaft to offer maximum feel for making a golf stroke. In addition to golf putters, such a leather wrap was also used on the grip for other golf clubs.
Over time, with the introduction of new materials to golf equipment, the material for grips for a golf club shaft transitioned from leather to rubber. In addition, grips were made in various shapes and sizes offering golfers a choice in design. Recently, the popularity of over-sized grips for golf putters in particular has risen due to golfers' perceived benefit that such grips offered in eliminating the use of the hands in a golf stroke. Specifically, it is believed that an over-sized grip limits use of the hands which would not disrupt the angle of the putter head when making a stroke so that the face of the putter and ball meet at the desired angle to roll the ball along the golfer's intended line.
However, an over-sized grip for a golf putter has a number of drawbacks. First, the over-sized grip adds weight to the upper portion of the shaft away from the putter head located at the lower portion of the shaft. This disturbs the balance and feel of the putter head for the golfer, which are critical for a golfer in order to control the putter head. If a golfer cannot feel the weight of the putter head when making a stroke, it is difficult for the golfer to control the putter head in a way to roll the ball down the golfer's intended line.
Secondly, the size of an over-sized grip numbs the feel of the hands in a way as to deaden the feel of the ball striking the face of the putter head. This also reduces the sound of the putter head striking the ball. Both feel and sound are important for a golfer to determine if the ball struck the putter head directly in the center of the face of the putter head. Without the proper feel and sound, a golfer has a much harder time knowing if he or she has made solid contact with the ball during the stroke.
Thirdly, the size of an over-sized grip limits the golfer's sense of touch in his or her hand and fingers which adversely affects the golfer's ability to gauge and judge distance when putting. Specifically, golfers use their hands and fingers to relay a sense of touch to the brain. With this sense of touch impaired, it is more difficult for golfers to know how hard to strike the ball to achieve the desired distance of roll. To overcome the shortcomings of an over-sized grip for a golf club shaft in general and for putters in particular, there exists a need to aid golfers in feeling the weight of the head at the lower end of the shaft (i.e., opposite end from the grip), increase the awareness of feel in the hands of a golfer and improve the sound heard by a golfer when the ball strikes the face of the face of the golf club head and increase the sense of touch in the hands and fingers for controlling the distance the ball is rolled off the face of the golf club head.
A first aspect of the invention provides a grip for a shaft of a golf club, the golf club comprising a head provided at a first end of the shaft and a grip provided at a second end of the shaft, the grip comprising an elongate hollow cylindrical sleeve of heat-shrinkable material that is open on each end and adapted to be slidably inserted over the second end of the shaft and an under listing positioned along the second end of the shaft, wherein the sleeve is slidably inserted over the second end of the shaft and the under listing positioned thereon, and shrinks onto the second end of the shaft upon the application of heat. Preferably, the length of the elongate hollow cylindrical sleeve of heat-shrinkable material is approximately ten inches and the under listing provides a substantially flat, non-curved and non-circular surface for a golfer to rest the thumbs when gripping the grip. Preferably, the under listing is adhered onto the second end of the shaft.
A second aspect of the invention provides a method for forming a grip for a shaft of a golf club comprising a head provided at a first end of the shaft and a grip provided at a second end of the shaft, the method comprising positioning an under listing along the second end of the shaft, slidably inserting an elongate hollow cylindrical sleeve of heat shrinkable material that is open on each end over the second end of the shaft and the under listing positioned thereon, applying heat to the sleeve such that the sleeve shrinks onto the second end of the shaft. Preferably, the under listing is adhered onto the second end of the shaft before slidably inserting the sleeve over the second end of the shaft.
Further advantageous aspects of the invention will become apparent to those of ordinary skill in the art upon review of the following description of the embodiments of the invention and with reference to the accompanying drawings.
An embodiment of the invention is now described by way of example and with reference to the accompanying drawings:
Referring now to
Sleeve 20 is open on each end and may be formed by any convenient method, for example wrapping a sheet of suitable material on itself and welding or seaming its edges together to form an elongate hollow cylindrical tube shape. Sleeve 20 can also be formed by first extruding the raw material (pushing raw material for sleeve 20 through a die of the desired cross-section of sleeve 20) followed by expanding the resulting extruded material by blowing air or another suitable gas into the extruded material for the desired length. The length of sleeve 20 may be less than, substantially as long as, or longer than the length of a typical hand placement area of a golf club. Preferably, sleeve 20 is approximately ten inches.
Sleeve 20 is comprised of a thin-walled type material that is sufficiently thin and pliable during the heating stage to substantially conform to the shape of the second end 18 of shaft 12. The inner diameter of sleeve 20 preferably is larger than the width or diameter of second end 18 so as to allow sleeve 20 to be easily slidably inserted over second end 18 of shaft 12.
Referring now to
Under listing 30 is a thin structure with a preferred width, corresponding to the distance separating top longitudinal surface 32 and bottom longitudinal surface 34, of preferably approximately 9 mils to approximately 13 mils. The width W of under listing 30 preferably is sized to cover approximately one quarter (or ninety degrees) of the external surface (circumference) of second end 18 of shaft 12. Under listing 30 can be formed by any convenient method known in the art such as injection molding, extrusion, or three-dimensional (3D) printing.
Preferably, bottom longitudinal surface 34 of under listing 30 has adhesive characteristics so that when under listing 30 is positioned along second end 18 of shaft 12, bottom longitudinal surface 34 of under listing 30 adheres onto the exterior surface of second end 18 of shaft 12. The imparting of adhesive characteristics to bottom longitudinal surface 34 of under listing 30 can be performed using one of many known techniques in the art, such as the application of a liquid glue along the length of bottom longitudinal surface 34 or, preferably, the use of double-sided tape. Preferably, the adhesive characteristics of bottom longitudinal surface 34 are maintained before positioning along second end 18 of shaft 12 by covering surface 34 with a pull-away paper or plastic strip that, when removed, exposes the adhesive bottom longitudinal surface 34.
Referring now to
After positioning under listing 30 along second end 18 of shaft 12, sleeve 20 is slidably inserted over second end 18 of shaft 12 so that it overlays the entire length L of under listing 30. Sleeve 20 can be equal to or greater in length than under listing 30. Preferably, sleeve 20 is longer than under listing 30 by approximately one-half inch with approximately one-quarter inch of sleeve 20 extending beyond the lower portion of second end 18 and approximately one-quarter inch of sleeve 20 extending beyond the upper portion of second end 18 that is pushed into the interior of shaft 12 at butt 19. With sleeve 20 thus positioned, heat is then applied to the external surface of sleeve 20. The heat can be applied from one of many known heat sources known in the art such as a heat lamp, heat gun, or hair dryer. The heat is applied all around the exterior surface of second end 18 of shaft 12 until sleeve 20 shrinks onto the exterior surface of second end 18 of shaft 12 and conforms to the shape of shaft 12 so that sleeve 20 holds itself in position on second end 18 of shaft 12 during use of club 10 by the shrink-wrapping process. A preferred method of applying the heat is the use of a back-and-forth motion along the length of sleeve 20 at a distance from sleeve 20 of between approximately one-half to approximately one inch while rotating shaft 12 so as to heat the entire length of sleeve 20 around the entire exterior surface of second end 18.
Grip 40 is sufficiently thin so that when a golfer grips second end 18 of shaft 12 at grip 40, the golfer can feel the weight of the head at the first end 16 of the shaft, increasing the awareness of feel in the hands of the golfer, with less deadening of sound when head 14 strikes the ball, compared to typical prior art thicker grips.
The invention is not limited to the embodiments descried herein which may be modified or varied without departing from the scope of the invention.
