Laser marking of molded hand grips

A method is provided for marking a molded hand grip such as a golf grip (100) with specialized information such as a personalized signature. The method utilizes a laser marking device (50) that is operative to provide an optical beam (8) having power and optical wave length characteristics effective to vaporize a continuous groove or trench and/or adjacently positioned dots in a target region ("R") on the hand grip to which beam (8) is exposed. The marked grip is then removed from device (50) and a selected colorant (16) such as paint or ink of desired color is then deposited in the marking that is preferably bondable to the desired extent to the material from which the hand grip is molded after which any excess colorant is then removed to provide the finished hand grip having the specialized information marked thereon.

This invention relates generally to a method for marking molded hand grips 
and more particularly to a method for laser marking already molded hand 
grips with specialized information such as insignia, logomarks, brand 
names, personalized signatures and the like. 
BACKGROUND OF THE INVENTION 
Many hand grips and most golf hand grips are currently being made by a 
molding process and any design or marking desired on the outside of the 
grip must be designed into the mold so that the marking is in the form of 
a depression or groove in the resultant molded product outer surface into 
which a suitable paint is then characteristically applied with any excess 
being removed such as by wiping, buffing or sanding. 
Such process however, would be extremely costly and limited in versatility 
in cases where individualized marking is desired since special molds would 
have to be made to satisfy individual customer request. 
Surprisingly, no one prior to the present invention had thought to utilize 
laser technology for marking specialized information on already molded 
hand grips so that either or both the manufacturer and distributor could 
provide such specialized marking in response to individual customer 
request. 
Although laser marking devices have been available in the market place for 
many years, they have not heretofor been employed to mark information on 
already molded hand grips. 
Informative descriptions of commercially available laser devices can be 
found for example in "Proceedings of the Society of Photo-Optical 
Instrumentation Engineers" (SPIE) in Volume 86, pp. 23-29, 1976, in an 
article by M. J. Weiner entitled "PRODUCT MARKING WITH NA: YAG and 
C0.sub.2 LASERS" and in Volume 247, pp. 18-23, 1980 in an article by 
Ronald L. Hansen entitled "EODYMIUM YTTRIUM ALUMINUM GARNET (Nd: YAG) 
LASER MARKING SYSTEMS". 
Although the above described SPIE articles are replete with information 
concerning electronic circuitry associated with the respective devices and 
their ability to mark by vaporizing adjacently positioned dots or 
continuous grooves or tunnels in metal, plastic and rubber materials, no 
one heretofor had thought to apply such laser technology to mark already 
molded hand grips with personalized information such as insignia, brand 
names, logomarks, signatures and the like which would otherwise be 
extremely impracticable where such had to be accomplished by engraving the 
molds. 
An example of a laser cutting device for tape controled cutting is 
disclosed in U.S. Pat. No. 4,469,930 the disclosure of which is 
incorporated herein by reference. An example where a laser device is used 
to engrave printing copper plate is disclosed in U.S. Pat. No. 4,516,496, 
the disclosure of which is incorporated herein by reference. An example of 
laser cutting tire treads in blank prototype blocks is disclosed in U.S. 
Pat. No. 4,564,737, the disclosure of which is incorporated herein by 
reference. 
None of the above patents however, singularly or in any combination with 
the above described SPIE articles disclose or suggest the marking method 
of the present invention. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide a method for 
marking information on an already molded hand grip. 
It is another object of this invention to mark an already molded hand grip 
with personalized information such as insignia, brand names, logomarks, 
personalized signatures and the like. 
It is a more particular object of this invention to provide a method 
employing a laser device for marking information on already molded hand 
grips.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS 
A molded hand grip in the form of a golf hand grip 100 is provided in step 
(a) of FIG. 1. Golf grip 100 also is a molded grip that is to be marked by 
the method of the present invention. 
Golf grip 100 has designs such as Chevrons 2 and the arrow 4 molded into 
its outer surface for common distribution in the market place. Golf grip 
100 has an end cap 6 secured to its end that itself may contain markings 
for common distribution in the market place. 
Golf grip 100 also has a region referenced by the letter "R" that is the 
target region to be marked with specialized information by the method of 
the invention. 
Golf grip 100 is molded from a laser vaporizable material that is vaporized 
by a laser marking device 50 such as shown in step (b) of FIG. 1. Golf 
grip 100 is preferably molded from a material selected from the group of 
materials consisting of thermoplastic elastomers and rubber materials 
having durometer and toughness and gripping characteristics attractive for 
conditions under which the game of golf is apt to be played. 
Examples of thermoplastic elastomers suitable for golf hand grips include 
lower durometer block copolymers sold under the "KRATON" trademark by 
Shell Chemical Company. Rubber compositions suitable for golf grips 
applications include natural rubber, synthetic polymers or combinations of 
both compounded with plasticizers, stabilizers, U.V. inhibitors and other 
additives well known to those skilled in the art of rubber hand grip 
materials. 
A laser marking device 50 is provided in step (b) in FIG. 1 as previously 
described. Device 50 is operative to provide an optical beam having power 
and optical wave length characteristics effective to vaporize the selected 
hand grip material in a marking form having the breadth and depth desired. 
Device 50 is operative to receive and mark specialized information on a 
target region exposed to the laser beam of which the personalized 
signature "Tracy" is an illustrative example. 
The information to be marked may be received by device 50 in a variety of 
forms such as by typing or by means of tape or by means of a parallel 
stylus marking system by which the laser beam tracks the stylus movement 
as directed by intermediate electro-mechanical interconnections. 
Device 50 may for example be of the programmable type that stores the 
information to be marked on the hand grip in memory which is then retrieve 
in response to a command signal that is referenced in step (b) by the 
numeral "C". 
As shown in step (b) of FIG. 1, when the laser is activated by command 
signal "C", a laser optical beam 8 is produced that impinges upon a 
reflective optical positioner 10 that is operable to move in at least the 
plane perpendicular to the beam to provide the marking desired by 
vaporizing a continuous groove or trench having the breadth and depth 
desired in the target material to which the laser beam 8 is exposed. 
Device 50 may include a "Q" switch that is operative to turn laser beam 8 
on and off at a selected rate to create a pulsed signal that in 
combination with either the beam movement in the plane perpendicular to 
the beam creating what is known in the laser marking trade as "dots" that 
are adjacently positioned and are used in many marking applications. 
In some instances, the marking device may provide a stationary optical beam 
8 and the target itself is caused to traverse across the beam in a manner 
operative to enable the beam to mark the product with the desired 
information. 
In yet another variation, a mask 14 having the information to be marked cut 
the therethrough may be inserted between laser beam 8 and the target 
region such that the beam casts an image of the information to be marked 
on the target and which then proceeds to vaporize the material beneath the 
image to the breadth and depth desired. 
In yet a further variation, the marking produced by the laser device may be 
a combination of both a continuous groove or trench and adjacently 
positioned dots. 
Thus, numerous variations may be employed to laser mark a target region 
such as region "R" of golf grip 100 exposed to laser beam 8 in step (c) 
with information desired such as by traversing the optical beam across the 
target region or by traversing the target region across the optical beam 
or by traversing both the beam and the target relative the other either 
continuously to mark the target region material with a continuous groove 
or trench or by employing a "Q" switch or equivalent operative to pulse 
the laser beam to mark the target region material with adjacently 
positioned dots in a manner providing the marking desired. 
The laser produced dots and/or grooves providing the marked information 
created in step (c) are then at least partially filled with a selected 
colorant in step (d) such as a paint or ink in contrasting color to the 
color of golf grip 100 by means such as paint brush 18. Colorant 16 has 
the desired color and is preferably bondable to the extend desired to the 
selected material for which golf grip 100 is molded. 
Any excess colorant in the marked target region of golf grip 100 is then 
removed such as by wiping and/or sanding, and/or buffing the surface of 
region "R" such as illustrated by rotary buffing wheel 20 in step (e) of 
FIG. 1 that then provides the resulting golf grip 100 having the 
personalized signature "Tracy" marked thereon.