[0027] Referring to FIGS. 2 and 3, a first embodiment of a golf club head in accordance with the present invention comprises a body 1, at least one vibration-absorbing member 2 (three in this embodiment), and at least one adjusting member 3 (three in this embodiment). The body 1 is a body for an iron club head. The body 1 is engaged with a striking plate 11 and includes a back cavity 12 and at least one compartment 13 (three in this embodiment). The body 1 can be engaged with the striking plate 11 by welding, brazing, insertion, or screwing. The striking plate 11 has a front side for striking golf balls. Alternatively, the body 1 and the striking plate 11 can be integrally formed with each other, with the striking plate 11 being a striking face of the body 1 for striking golf balls.
[0028] The back cavity 12 is defined in a rear side of the body 1. The rear side of the striking plate 11 is thus exposed. Each compartment 13 is defined in a lower portion of the rear side of the body 1 and includes a rearward-facing opening (not labeled). Each compartment 13 is delimited by a portion of the rear side of the striking plate 11. Preferably, each compartment is delimited by an area of the rear side of the striking plate 11 that is opposite to the sweet spot or the residual vibration concentrating area, such as the heel or toe of the rear side of the striking plate 11. Further, each compartment 13 is preferably cylindrical and includes an inner threading 131 in an inner periphery delimiting the compartment 13.
[0029] As illustrated in FIGS. 2 and 3, each vibration-absorbing member 2 is bonded to a perimeter wall delimiting the compartment 13 or slidably received in the associated compartment 13. Preferably, each vibration-absorbing member 2 is in intimate contact with the associated portion of the rear side of the striking plate 11.
[0030] Each vibration-absorbing member 2 includes a bladder 21 defining a gas chamber 22 therein. The bladder 21 is made of an elastomeric material such as rubber, polyurethane (PU), thermoplastic elastomers, or high-molecular elastomeric resins. The elastomeric material preferably has a hardness between Shore A 10 and Shore D 30. The gas chamber 22 defined in the bladder 21 is sealed, with an appropriate amount of gas being filled into the gas chamber 22 to a pressure not less than the atmosphere.
[0031] Each adjusting member 3 is preferably a screw with an outer threading 31 and a slot 32 for engaging with a screwdriver or the like. The outer threading 31 of each adjusting member 3 is threadedly engaged with the inner threading 131 of the associated compartment 13. A golfer may use a screwdriver or other tool to drive adjusting member 3, moving the adjusting member 3 toward or away from the associated vibration-absorbing member 2, thereby adjusting the pressing force exerting on the rear side of the striking plate 11 by the vibration-absorbing member 2 and thereby adjusting a compressed amount of the vibration-absorbing member 2.
[0032] During hitting of a golf ball by the golf club head, the golf ball comes in contact with the striking plate 11 at the first stage, results in maximum deformation of the striking plate 11 at the second stage, and leaves the striking plate 11 at the third stage. During each stage of the golf ball, the striking plate 11 deforms rearward and creates a stress pressing against each vibration-absorbing member 2, resulting in continuous compression of each vibration-absorbing member 2. The volume of each vibration-absorbing member 2 changes accordingly.
[0033] As mentioned above, an appropriate amount of gas is contained in the gas chamber 22, allowing easy elastic compressive deformation when each vibration-absorbing member 2 is subjected to a stress. Namely, at the first stage of the golf ball mentioned above, the striking plate 11 begins to elastically deform and imparts a smaller stress to each vibration-absorbing member 2, and this stress gradually increases to allow rapid momentary compression of each vibration-absorbing member 2. Thus, the golf club head in accordance with the present invention avoids each vibration-absorbing member 2 from overpressing against the striking plate 11 at the first stage, prolonging the contact time between the golf ball and the striking face 11 while assuring the overall striking effect.
[0034] At the second stage mentioned above, the striking plate 11 reaches its maximum deformation and creates the maximum stress that compresses the gas cushion 2 to the maximum extent. Each vibration-absorbing member 2 bears the striking plate 11 and further prolongs the contact time between the golf ball and the striking plate 11, further improving the direction controllability and striking accuracy of the golf ball.
[0035] At the third stage mentioned above, the stress from the striking plate 11 gradually reduces to zero. In response, the volume of each vibration-absorbing member 2 rapidly resumes its original value. Thus, after the golf ball has been stricken, although a part of momentum is not imparted to the golf ball and thus results in residual vibrations of the striking plate 11, the vibration-absorbing members 2 in intimate contact with the rear side of the striking plate 11 effectively absorb the residual vibrations and thus improve the gripping comfort.
[0036] Referring to FIG. 3, as mentioned above, each adjusting member 3 can be turned to adjust the pressing force exerting on the rear side of the striking plate 11 by the vibration-absorbing member 2 and to adjust the compressed amount of the vibration-absorbing member 2. Thus, before hitting a golf ball, if an adjusting member 3 is turned to press against the associated vibration-absorbing member 2 to a greater extent, the associated vibration-absorbing member 2 is pre-loaded with a pre-loaded stress and pre-pressed to a smaller volume. Thus, the associated vibration-absorbing member 2 presses against the striking plate 11 to a greater extent and thus has a higher vibration-absorbing capacity. On the other hand, if the adjusting member 3 is turned to press against the associated vibration-absorbing member 2 to a smaller extent or to be in loose contact with the associated vibration-absorbing member 2, a larger buffering space is provided between the associated vibration-absorbing member 2 and the striking plate 11, or a loose contact is provided between the associated vibration-absorbing member 2 and the striking plate 11. Thus, the associated vibration-absorbing member 2 does not overpress against the striking plate 11 and thus has a lower vibration-absorbing capacity while assuring the striking effect, prolonging the contact time between the golf ball and the striking plate 11, improving the direction controllability, and improving the striking accuracy of the golf ball.
