Grip assembly and method

A grip for an apparatus having a shaft comprises an elongate hollow sleeve adapted to be slidably inserted on to the shaft and is shrinkable upon the application of heat at a preselected temperature range so that the sleeve contracts and surroundingly attaches to the shaft. A tubular member is adapted to be slidably inserted over the sleeve such that the sleeve and the tubular member together form an easily attachable grip. In a further aspect of the invention the sleeve and/or the tubular member are provided with an adhesive. The adhesive may take the form of a two part curable adhesive such as an epoxy. One of the parts is applied to the outer surface of the sleeve and the other part is applied to the interior surface to the tubular member such that the parts mix upon sliding of the grip sections upon one another. In another embodiment of the invention, the two part adhesive is applied to either the exterior of the sleeve or the interior of the tubular member. One of the parts is encapsulated within rupturable microcapsules such that when the respective grip sections slide over one another, the microcapsules rupture, resulting in mixing of the epoxy components and the formation of an integral grip upon curing of the epoxy.

FIELD OF THE INVENTION 
This invention relates generally to the field of hand grips for use on tool 
and recreational equipment shafts and more particularly to grips employed 
on golf clubs. 
BACKGROUND OF THE INVENTION 
Grips are found on virtually every type of hand tool, sport rackets and 
clubs. Each of the foregoing therefore requires an grip to be provided at 
the time of sale and often, if the equipment is frequently used, the grip 
must be replaced. 
The grip that is provided when the product is purchased new is often 
applied with sophisticated and expensive molding equipment. However, when 
a replacement grip is applied by the consumer, it can be a time consuming 
and messy process which yields less than optimal results. For example, the 
grip portions of tennis rackets and baseball bats are often wound with a 
sticky gauze material to reinforce an existing grip. In addition, another 
replacement grip is disclosed in U.S. Pat. No. 5,419,031 to McLendon which 
teaches a golf club grip that is shipped to the consumer in an inside out 
state. The grip is placed on the shaft and is unrolled on the shaft by the 
consumer. Another golf grip is disclosed in U.S. Pat. No. 5,258,088 and 
provides for a solvent to be sprayed on to the club shaft. The grip 
assembly is coated with a layer of resin over the interior surface thereof 
such that when the grip is slid on to the shaft, the resin is dissolved 
into a glue that secures the rod inside the sleeve. After insertion of the 
rod into the sleeve and after the setting of the glue, the rod and the 
sleeve are incorporated into a unitary golf grip assembly. Thus, it will 
be seen that the foregoing grips are not without their inherent drawbacks 
and deficiencies. 
In view of the foregoing, it would therefore be of commercial value to 
provide a grip system which overcomes the drawbacks and deficiencies of 
the prior art grips. 
Accordingly, it is an object of the present invention to provide a grip 
that may be easily inserted onto a shaft for both original and replacement 
grips. 
Another object of the present invention is to provide an improved grip 
which, once attached, may be easily removed. 
Yet another object of the present invention is to provide an improved grip 
which is inexpensive. 
A still further object of the present invention is to provide an improved 
grip which is simple to manufacture. 
SUMMARY OF THE INVENTION 
The foregoing objects are accomplished by providing a grip for an apparatus 
having a shaft. The grip comprises an elongated hollow sleeve adapted to 
be slidably inserted on to the shaft and is shrinkable upon the 
application of heat at a preselected temperature range so that the sleeve 
contracts and surroundingly attaches to the shaft. A tubular member is 
adapted to be slidably inserted over the sleeve such that the sleeve and 
the tubular member together form an easily attachable grip. 
In a further aspect of the invention the sleeve and/or the tubular member 
are provided with an adhesive. The adhesive may take the form of a two 
part curable adhesive such as an epoxy. One of the parts is applied to the 
outer surface of the sleeve and the other part is applied to the interior 
surface to the tubular member such that the parts mix upon sliding of the 
grip sections upon one another. 
In another embodiment of the invention, the two part adhesive is applied to 
either the exterior of the sleeve or the interior of the tubular member. 
However, one of the parts is encapsulated within rupturable microcapsules 
such that when the respective grip sections slide over one another, the 
microcapsules rupture, resulting in mixing of the epoxy components, 
whereby an integral grip is formed upon curing of the epoxy.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
While the present invention will be described more fully hereinafter with 
reference to the accompanying drawings, in which particular embodiments 
are shown, it is to be understood at the outset that persons skilled in 
the art may modify the invention herein described while still achieving 
the favorable results of this invention. Accordingly, the description 
which follows is to be understood as a broad teaching disclosure directed 
to persons of skill in the appropriate arts and not as limiting upon the 
present invention. 
Referring more specifically to the drawings, it will be noted that the grip 
is illustrated as being mounted on the end of a generic shaft S. The 
present invention is intended to broadly include any type of grip, 
including, but not limited to golf grips, baseball bats, rackets (tennis, 
racquetball, bad mitten, cricket, squash, table tennis, etc.), bicycle 
handle bars as well as all types of tools having a grip. Notwithstanding 
the foregoing, specification which follows make reference to a golf grip, 
however, this is for ease of description and readability only and is not 
to be inferred as limiting upon the invention. 
Referring now particularly to FIGS. 1a and 1b, the grip generally indicated 
at 10 is mounted on a shaft S. The grip 10 comprises a sleeve 20, a 
tubular member 50 and an optional end cap 90, as will be more fully 
explained hereinbelow. 
The sleeve 20 is an elongate, hollow member having an outer surface 22 and 
an inner surface 24. The sleeve 20 is adapted to be slidably inserted on 
to the end of shaft S. The sleeve 20 is fabricated from a polyolefin and 
is shrinkable upon the application of heat at a preselected temperature 
range. The polyolefin employed in the present invention is designed to 
shrink at temperatures between about 55 degrees C. and about 90 degrees 
C., somewhat lower than current shrink wrap material. The foregoing 
temperature range was selected as conventional hand held hair dryers found 
in most homes operate at this temperature and the consumer can perform the 
necessary operation themselves without having to purchase any additional 
supplies or equipment. The unique property of polyolefins is that it is 
molded to the finished configuration and is then expanded to a greater 
diameter with super heated compressed air. It is then rapidly cooled and 
remains in this new shape. After shrinking, the sleeve remains pliant and 
conforms to the shape of the shaft. The chemistry and characteristics of 
polyolefins are well known to those skilled in the art and a detailed 
discussion thereof is not deemed necessary. As employed in the present 
invention, the sleeve 20 may be molded or extruded (depending on whether 
the fins, to be discussed hereinbelow are uniform or tapered). 
The grip 10 illustrated in FIG. 1a comprises an inner sleeve 20, a tubular 
member 50 and an end cap 90. It will be noted that this embodiment differs 
from those others illustrated herein in that no channels or fins are 
required. Referring now to FIG. 1b, the sleeve is illustrated as having a 
plurality of spaced fins 26 extending along its longitudinal axis on the 
exterior surface thereof. It will be noted that the fins in the embodiment 
illustrated in FIG. 2 are uniform in height and the fins illustrated in 
FIG. 3 are tapered in height, being taller at one end than the other. 
A tubular member 50 is provided and is adapted to be slidably inserted over 
the sleeve 20. The tubular member 50 may include a plurality of spaced 
channel means 52 positioned in corresponding relation to the fins 26, such 
that when the tubular member 50 is slidably inserted over the sleeve, the 
respective fins 26 and channels 52 are in contacting mating relation. In 
order to accommodate shafts of varying diameter with a single grip system, 
the tubular member may be provided with a plurality of expansion pleats 54 
(best illustrated in FIG. 6) which operate to increase the circumference 
of the interior diameter of the tubular member as needed. The expansion 
pleats 54 are positioned adjacent at least one of the channels 52 and 
extend along the length thereof. The pleats 54 operate in much the same 
manner as conventional pleats found in connection with other items, such 
as clothing, i.e., they stretch upon the application of force thereto. It 
will be noted that the sleeve 20 does not require expansion pleats as the 
shrink wrap process ensures a tight fit between the sleeve 20 and the 
shaft S. 
As many types of grips are subjected to high impact impulse type forces, 
such as a hammer striking a nail, or a golf club striking a golf ball, 
additional grip strength is sometimes required. This additional strength 
is provided by gluing the sleeve 20 and the tubular member 50 together. A 
two part curing adhesive such as an epoxy adhesive 70 (having parts A and 
B) is used. One part of the epoxy 70 (part A) is applied to the outer 
surface of the sleeve 20 and the other part (part B) is applied to the 
inner surface of the tubular member 50. It is necessary for the respective 
parts A and B to remain separated until the grip 10 is assembled at which 
time the epoxy parts are mixed by the action of the tubular member 50 
sliding over the sleeve 20 and the epoxy cures thereby bonding the sleeve 
20 and the tubular member 50 together. 
In an alternate embodiment, the two parts of the epoxy adhesive are applied 
together to either the exterior of the sleeve 20 or the interior of the 
tubular member 50, preferably on the fins 26 or channels 52. However, in 
order to prevent premature curing of the epoxy, one of the parts is 
encapsulated in rupturable microcapsules 60 (FIG. 15). Upon insertion of 
the tubular member 50 over sleeve 20, the pressure of the surfaces sliding 
over each other causes rupture of the microcapsules, mixing of the 
adhesive constituent parts and subsequent curing thereof. 
The microcapsules can range in size from about one micron to about one 
thousand microns, depending upon the particular application. The 
microcapsules are formed according to conventional methods, well known to 
those skilled in the art. The reader is referred to any one of the 
following texts for additional information on the fabrication of 
microcapsules: 
Books on Microencapsulation 
1. Vandergaer, J. E., Ed: Microencapsulation: Processes and Applications. 
Plenum Press, New York, 1974. 
2. Gutcho, M. H.: Microcapsules and Microencapsulation Techniques. Noyes 
Data Corp., Park Ridge, N.J. 1976. 
3. Ranney, M. W.: Microencapsulation Technology, Noyes Development Corp., 
Park Ridge, N.J., 1969. 
4. Kondo, A.: Microcapsule Processing and Technology. Marcel Dekker, Inc., 
New York, 1979. 
5. Nixon, J. R.: Microencapsulation. Marcel Dekker, Inc., New York 1976. 
In yet another embodiment of the invention, a hot melt adhesive is applied 
either to the fins 26 (FIG. 1a) or in the channels 52. Once the tubular 
member 50 is in the proper position over the sleeve 20, a heat gun (such 
as a hand-held home hair dryer) is employed to melt the adhesive and to 
bond the respective sleeve and tubular member together, thusly forming an 
integral grip. It will be noted that in the foregoing embodiment as well 
those mentioned hereinabove wherein adhesive is applied to either the fins 
and/or the channels, that the depths of the channels on the tubular member 
are slightly lower than the height of the fins on the sleeve. This allows 
the sleeve 20 to be internally coated with the epoxy where part B is 
encapsulated and suspended in part A. 
The top of the tubular member is open and a separate cap 90 pressure locks 
into the tip of the grip and is secured in place by means of the adhesive, 
previously described. 
With respect to golf club shafts in particular, they will vary in diameter 
between manufacturers, but are normally tapered, being narrower at the 
head end of the club and wider at the grip end. In accordance with the 
present invention, the sleeve 20 will shrink to accommodate any size 
shaft. By including expansion pleats 54 in the tubular member 50, it too 
will accommodate any variations in diameter. Once the tubular member 50 is 
pulled up over the sleeve, the epoxy will seep into the pleats and will 
aid in securing the tubular member to the sleeve. 
When attaching the grip to a shaft, the tubular member 50 is first slipped 
over the shaft S and thereafter, the sleeve 20 is also slipped over the 
end of the shaft S so that the end of the sleeve is flush with the end of 
the shaft. Then heat is applied to the sleeve with the heat gun to shrink 
wrap the sleeve 20 about the shaft. Next, the tubular member 50 is slid 
back down toward the end of the shaft and over the sleeve so that the 
respective fins 26 and the channels 52 are in alignment with one another 
and further, such that the tubular member 50 overlies the sleeve. 
Thereafter, if appropriate, heat is again applied to the tubular member 
about its circumference in order to melt the hot melt adhesive 70 and to 
fuse the sleeve and tubular member together. In the event a two part 
adhesive is employed, no further action is required in order to fuse the 
sleeve 20 and the tubular member 50 together. Lastly, if required, the end 
cap 90 is placed on the end of the tubular member 50 and adhesive 70 that 
has been forced toward the end of the shaft S is employed to hold the end 
cap 90 in place. 
The foregoing embodiments and examples are to be considered illustrative, 
rather than restrictive of the invention, and those modifications which 
come within the meaning and range of equivalence of the claims are to be 
included therein.