[0001] This invention relates to a games racket provided with a vibration-damping assembly.
[0002] Rackets made of metal and/or composite materials lack the inherent vibration-damping
characteristics of wooden rackets. Thus, in the case of metal and/or composite rackets,
additional damping means are desirable.
[0003] Accordingly, the present invention provides a games racket comprising a head for
stringing, a shaft and a handle, together with a throat portion joining the head and
the shaft to each other, in which the throat portion includes one or more vibration-damping
assemblies.
[0004] Preferably, one single vibration-damping assembly is located on the throat portion
at or near to an antinode of vibration of the racket, suitably on the longitudinal
axis of the racket.
[0005] Alternatively, two vibration-damping assemblies are located on the throat portion,
said assemblies being symmetrically placed relative to the longitudinal axis of the
racket.
[0006] In accordance with the present invention, each vibration-damping assembly comprises
a vibrating-member and one or more elastically-deformable mounting-members, said mounting-members
attaching the vibrating-member to the racket whereby said vibrating-member is capable
of free and elastic movement in the direction of an applied vibration.
[0007] Preferably, the direction of vibration is substantially perpendicular to the plane
of the racket stringing.
[0008] The vibrating-member is of a high-density material such as a metal and suitably comprises
a metal rod having a mass of from 5 to 15 g.
[0009] the elastically-deformable mounting-members may be made of natural rubber, a synthetic
rubber or a rubber-like material. A suitable material is the cellular material available
under the Registered Trade Mark SORBOTHANE.
[0010] The present invention will be illustrated, merely by way of example, in the following
description and with reference to the accompanying drawings.
[0011] In the drawings (wherein like reference numerals denote like parts) :
Figure 1 is a schematic view of a racket incorporating a vibration-damping assembly
according to the present invention;
Figure 2 is a section on line II-II of Figure 1.
[0012] The racket, shown generally at 10, comprises a head 11 for stringing (not shown),
a shaft 12 and a handle 13. A throat portion 14 joins the head and the shaft to each
other. A single vibration-damping assembly, shown generally at 20, is located on the
throat portion 14 on the longitudinal axis of the racket.
[0013] Referring now to Figure 2, the throat portion 14 is provided with a hole to receive
a vibrating-member comprising a metal rod 21. The rod is further provided with heads
22 and 23 to locate the rod. The mounting-members comprise two deformable bushes
30 and 31, which permit movement of the rod within the throat portion in response
to applied vibration when the racket is used in play. Movement takes place in the
direction of arrow AA′.
[0014] A vibration-damping assembly 20 according to the present invention was fitted to
one of two otherwise identical metal-framed tennis rackets. The metal rod 21 weighed
7 g and the deformable bushes 30 and 31 were made of natural rubber.
[0015] The rackets were tested for vibration properties under unrestrained conditions and
the vibration damping properties were found to be as follows :
Racket without damper : 19 units
Racket with damper : 23 units
[0016] The figures for vibration damping are calculated as follows :
Vibration damping = log
e (vibration decrement) x 10³
[0017] The higher the figure the better the damping. The vibration properties described
can readily be measured by those skilled in the art.
1. A games racket comprising a head for stringing, a shaft and a handle, together
with a throat portion joining the head and the shaft to each other, characterised in that the throat portion (14) includes one or more vibration-damping assemblies (20).
2. A racket according to Claim 1, characterised in that one vibration-damping assembly (20) is located on the throat portion (14) at or near
to an antinode of vibration of the racket (10), for example on the longitudinal axis
of the racket (10).
3. A racket according to Claim 1, characterised in that two vibration-damping assemblies (20) are located on the throat portion (14), said
assemblies (20) being symmetrically placed relative to the longitudinal axis of the
racket (10).
4. A racket according to Claim 1, 2 or 3, characterised in that each vibration-damping assembly (20) comprises a vibrating-member (21, 22, 23) and
one or more elastically-dependable mounting-member (30, 31), said mounting-members
(30, 31) attaching the vibrating-member (21, 22, 23) to the racket, whereby said vibrating-member
(21, 22, 23) is capable of free and elastic movement in the direction (AA′) of an
applied vibration.
5. A racket according to Claim 4, characterised in that the direction of vibration (AA′) is substantially perpendicular to the plane of the
racket stringing.
6. A racket according to Claim 5 or 6, characterised in that the vibrating-member (21, 22, 23) consists of a high -density material, for example
a metal rod, and in that it has a mass of from 5 to 15 g.
7. A racket according to Claim 4, 5 or 6, characterised in that the elastically-deformable mounting-members (30, 31) are made of material rubber,
synthetic rubber or rubber-like material, for example a cellular material.