Shock Absorbing iron head

An iron type golf club head has a cavity in a back and a continuous recess extending into the top surface, toe and a portion of the sole along the perimeter of the club head. The recess and a back wall of the cavity are spaced from the front striking surface to provide a front striking surface of a general uniform thickness. A vibration damping material is inserted in the recess.

FIELD OF THE INVENTION 
The present invention relates to an iron golf club having a shock absorbing 
head and a construction to achieve an enlarging effect of the sweet spot. 
BACKGROUND OF THE INVENTION 
It is known in the industry that a golf club head joined to a shaft can 
transmit vibrational energy up the shaft to the player when the club head 
strikes a ball. These vibrations can be distracting to players as well as 
effecting the accuracy of the strike. Various vibration dampers have been 
proposed to eliminate this vibrational effect on the player. 
U.S. Pat. No. 5,277,423 issued to Artus discloses a rigid tubular sleeve 
made of a visco-elastic material having a predetermined thickness and 
slidably connected to the shaft. The sleeve on the shaft serves as a 
vibration damping device by absorbing the energy released during the 
strike of a ball and converting it into heat. 
Other means to dampen the vibrational energy of a golf club is to 
incorporate the visco-elastic material directly adjacent the surface of 
the club head wherein the damping material is located closer to the source 
of vibration. U.S. Pat. No. 5,290,036 issued to Fenton et al. discloses 
such a iron golf club wherein a vibration dampening material is set in the 
back cavity of the iron head. A problem that can be encountered with this 
damping location is that the damping material could also dissipate the 
energy of the striking ball and thereby diminish the efficiency of the 
hit. 
Additionally, it was known in the industry to provide a perimeter weighted 
iron golf club head having a rear cavity in an attempt to provide a golf 
club head that improves off-center hits. Such iron heads are configured to 
redistribute the weight on the head, or to provide a uniform striking 
surface to maximize the performance of an off-center hit as well as an 
on-center hit. 
U.S. Pat. No. 5,046,733 issued to Antonious provides a peripheral or 
perimeter weighted iron golf club head having a second peripheral weight 
member adjacent the first peripheral weight member to maximize off-center 
hits of the ball. 
U.S. Pat. No. 5,282,625 issued to Schmidt et al. discloses a reconfigured 
iron head that achieves lateral sweet spot enlargement by providing 
undercuts at the toe and heel that extend outwardly from the rear cavity. 
SUMMARY OF THE INVENTION 
It is the object of the invention to provide an improved iron head having 
vibration damping means incorporated in the head such that it does not 
result in a loss of accuracy or efficiency when striking the ball. It is 
further another object of the invention to provide an iron head 
configuration that provides an enlarging effect of the sweet spot. It is 
also an object of the invention to provide an iron golf club set having 
these benefits that is easily manufactured. 
The aforementioned objectives are accomplished by providing an iron golf 
club head having a front face and back surface, wherein the back surface 
has a forwardly extending rear cavity that is located directly behind the 
front face. The golf club head further comprises a top surface, a toe, a 
sole, and heel, which together define the perimeter of the iron head. A 
recess is provided along the perimeter of the iron head that extends along 
the top surface, toe and sole of the club head. The recess is positioned 
along the perimeter of the club head at a predetermined distance from the 
front face such that the front face has a known thickness. The recess is 
further cut to a depth such that it ends proximate to the rear cavity. As 
a result, the front face has a consistent thickness essentially over its 
entire surface to effect an enlargement of the sweet spot. 
In addition, a vibrational damping means is incorporated into the iron head 
by inserting a viscoelastic polymer into the peripheral recess of the iron 
head. The damping effect of the polymer enforces the sweet spot 
enlargement by deadening the iron so that if the ball is hit off center, 
the of the ball does not significantly change. The damping means does not 
extend over the entire surface of the front face as in the prior art so 
that the damping means does not deaden the energy of the ball when struck 
by the iron golf club. 
Other objects, advantages and applications of the present invention will 
become apparent to those skilled in the art when the following description 
of the best mode contemplated for practicing the invention is read in 
conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1-5, the current invention is a perimeter weighted iron 
golf club head 10. The golf club head 10 has a front striking surface 12 
and a back wall 14. It further has a perimeter 16 defined by a top surface 
18, a toe 20, a bottom surface or sole 22 and a heel 24. The back wall 14 
has a forwardly directed cavity 26, in which an inner wall surface 28 of 
the cavity 26 is essentially parallel with the front striking surface 12. 
An upper wall 30 of a cavity is essentially parallel to the top surface 
18. The top surface 18 is essentially a flat wide surface having a width 
(W) dimension of approximately 0.25 mm, and remains a constant width from 
the heel 24 to the toe 20. 
The toe 20, as seen in FIG. 3, has a mass 32 at the sole 22 that 
progressively decreases to a uniform thickness (W) as it extends up to the 
top surface 18. The heel 24, as seen in FIG. 4, has a smaller mass 33 at 
the sole 22 that decreases to the thickness (W) the top surface 18. 
Along the perimeter 16 of the iron club head 10 starting proximate to the 
heel 24 on the top surface 18 is a recess 34 along the top surface 18 and 
extending continuously around the toe 20 and continuing along the sole 22. 
The recess 34 ends at a point on the sole 22 spaced from the heel 24 of 
the golf club head 10. In the preferred embodiment, the recess has side 
walls 35a, 35b that are parallel to each other. As seen in FIGS. 2 and 5, 
the recess 34 extends to a depth within the iron head 10 proximate to the 
cavity 26 whereby a bridge 36 joins the front striking surface area 12 to 
the back wall area 14 along most of the perimeter 16 of the golf club head 
10. As can be seen in FIGS. 3 and 5, the recess 34 is spaced from the 
front striking surface 12 at a distance consistent throughout its entire 
length around the perimeter 16. It is apparent from FIG. 5 that the recess 
34 is spaced from the front striking surface 12 at a distance equal to the 
distance that the inner cavity wall 28 is spaced from the front striking 
surface 12. The recess 34 is angled to correspond to the angle of the 
front striking surface 12 so that the recess 34 is parallel with the front 
striking surface 12. In this manner, it is evident to see that the front 
striking surface 12 has a uniform thickness over most of its surface, an 
exception being at the portion where the bridge 36 connects the front 
striking surface 12 with the back wall 14 portion. Providing an 
essentially uniform thickness for the striking surface 12 allows for an 
enlarged sweet spot effect. The bridge is ideally a thickness of 
approximately 2.0 mm to provide adequate support for connecting the 
striking surface 12 and the back wall 14, but yet providing a maximum 
uniform thickness of the striking surface 12 over a greater portion of the 
surface area of the striking surface. 
To provide a damping means to the golf club head 10, a visco-elastic 
material 38 having a high damping coefficient is inserted within the 
entire area of the recess 34, so that the damping material 38 is flush 
along the perimeter 16 of the golf club head 10. Typical visco-elastic 
materials that can be used are butyl rubber and other synthetic 
elastomers. The placement of the damping material 38 extending along the 
perimeter 16 of the golf club head 10 remedies problems encountered in the 
prior art. In the prior art when the visco-elastic material 38 was placed 
adjacent to the front striking face 12, excessive absorption of the energy 
from the ball impact was often observed resulting in a loss of efficiency. 
Having the damping material 38 along the perimeter 16 of the golf club 
head 10 minimizes the surface area of the striking surface 12 having ball 
impact with the damping material 38, but will effectively dampen the 
vibration to the player. In the preferred embodiment, the width of the 
recess 34 and thereby the thickness of the visco-elastic material 38 is 
approximately 5.0 mm, although the thickness may vary. 
Providing an outer perimeter recess 34 to effect an enlarged sweet spot on 
the front striking surface 12 provides an economic advantage over the 
prior art. The positioning of the recess allows the recess 34 to be cast 
in the golf club head 10 during the manufacturing process rather than cut 
into the cavity 34 afterwards as done in the prior art. The visco-elastic 
material 38 can then be easily inserted into the recess 34 with 
appropriate and conventional adhesives. 
While the invention has been described in connection with what is presently 
considered to be the most practical and preferred embodiment, it is to be 
understood that the invention is not to be limited to the disclosed 
embodiments but, on the contrary, is intended to cover various 
modifications and equivalent arrangements included within the spirit and 
scope of the appended claims, which scope is to be accorded the broadest 
interpretation so as to encompass all such modifications and equivalent 
structures as is permitted under the law.