referring now to fig1 to 4 , there is shown a damping device 1 for incorporation into a golf club 2 , which is a putter in this embodiment . the damping device 1 is an insert that includes an anchor element 3 and a damping element or frequency filter 4 that are interconnected by a rigid aluminium rod 5 . the anchor element 3 is in the form of a brass sleeve in this embodiment that is removably mounted to a first end of the rod 5 and that has a larger diameter than the rod 5 . the anchor sleeve 3 includes a pair of spaced grooves 30 with an o - ring 31 received in each groove 30 . the use of brass provides a relatively heavy component adjacent the head ( not shown ) of the putter 2 . the device 1 is therefore configured to maintain the position of the centre of gravity of the putter 2 despite the addition of the damping device 1 . in this embodiment , the device 1 is configured such that the overall weight , or dead weight , of the putter 2 is increased by approximately 100 grams , but the centre of gravity of the putter 2 is in the same position as it was prior to fitting the device 1 . the damping element 4 is also in the form of a composite sleeve in this embodiment that is removably mounted to the rod 5 adjacent a second end thereof and also has a larger diameter than the rod 5 . the composite sleeve 4 includes a base sleeve 40 with a spiral wrapped foam layer 41 adhered thereto . the foam layer 41 is formed of a foam strip with a high bond self adhesive and an anti stretch mesh on one side thereof . the configuration of the foam layer 41 is selected to provide optimum damping , which is discussed in more detail below . the rod 5 includes a recess 50 at its first end on which the anchor sleeve 3 is mounted and an externally threaded portion 51 at its second end for cooperation with an insertion tool ( not shown ). the rod 5 also includes a pair of grooves 52 adjacent the second end each of which receives a respective o - ring 53 for fastening the damping sleeve 4 therebetween . the rod 5 further includes a lock means to lock the anchor sleeve 3 to the rod 5 . the lock means includes a ball 54 received within a transverse hole 55 in the rod 5 adjacent the first end and a grub screw 56 that engages an threaded axial hole 57 in the second end of the rod 5 and that intersects with the transverse hole 55 . the grub screw 56 has a tapered end such that tightening of the grub screw 56 causes the ball to ride up the transverse hole 55 toward the anchor sleeve 3 to secure it in place . in use , the shaft 20 is first cleaned using a 410 barrel cleaning brush ( not shown ) to remove any dirt , rust , burrs or the like . the damping device 1 is then fitted into the shaft 20 of the putter 2 such that the anchor sleeve 3 is anchored in a lower , straight portion of the shaft 20 , preferably at or adjacent the centre of gravity of the putter 2 , while the damping sleeve 4 contacts an upper portion of the shaft 20 remote from the centre of gravity . the rod 5 therefore spans the centre of the shaft 20 . this may be accomplished using a bespoke tool ( not shown ) that cooperates with the threaded end 51 to allow a fitter ( not shown ) to insert the device 1 into the open end of the shaft 20 . it is also possible to use a small amount of grease ( not shown ) to facilitate insertion of the anchor sleeve 3 into the shaft 20 . it has been observed that the damping device 1 of the invention remains secured properly despite the use of such grease . the tool ( not shown ) is used to force the device 1 into the shaft 20 and preferably includes a graduated scale ( not shown ) indicating the depth of the device 1 within the shaft 20 . it is envisaged that the fitter ( not shown ) would be provided with instructions as to what depth is required for the particular golf putter 2 being fitted . in use when the putter 2 strikes a golf ball ( not shown ), the vibrations transferred from the head ( not shown ) of the putter 2 to the shaft 20 are then transferred into the rod 5 , which oscillates in both a longitudinal direction ( i . e . resulting in small transverse oscillations ) and in a twisting direction along the shaft 20 . the damping device 1 is configured such that these oscillations are partially absorbed by the damping sleeve 4 to reduce and / or regulate the vibrations , for example the amplitude and / or the frequency of the vibrations , running up the shaft 20 and into the golfer &# 39 ; s hands . it has been observed that this arrangement also effectively increases the area of the sweet spot when the device 1 is configured and positioned correctly . more specifically , if the foam layer 41 is too dense the vibrations will travel from the shaft 20 to the anchor sleeve 3 through the rod 5 through the damping element 4 and back into the shaft 20 with little effect . moreover , if the foam layer 41 is not dense enough , the oscillations that pass into the rod will not be absorbed properly . the density of the foam layer 41 should therefore be selected to provide optimal damping whilst avoiding these two extremes . this is achieved by providing a damping sleeve 4 based on the specific design of the putter 2 , wherein the degree of interference fit between the damping sleeve 4 and the putter 2 is preselected to achieve the desired result . referring now to fig5 to 12 , there is shown a damping device 100 and installation tool 200 according to a second embodiment of the invention , which is similar to the damping device 1 of the first embodiment wherein like references depict like features that will not be described further . the damping device 100 according to this embodiment differs from that of the first embodiment in that the anchor element 103 is in the form of a split collet 130 filled with an elastomeric material , urethane rubber , and the damping element 104 includes a foam layer wrapped directly on the rod 105 and retained thereon by a pair of ferrules 140 and encased in shrink wrap to prevent damage or catching of the resilient material or layer when the device 100 is installed or removed . the elastomeric material enables repeated and / or resilient compression of the collet 130 , thereby permitting the device 100 to lock into a greater tolerance of shaft diameters . the anchor element 103 is secured to the rod 105 by a threaded engagement ( not shown ) and extends beyond the end of the rod 105 to reduce the rigidity with which the rod 105 is secured and cantilevered to provide a further damping effect . the damping device 100 also includes an optional damping extension 110 including a first end 111 with an internal thread for threaded engagement with the threaded portion 51 and , a second end with a further threaded portion 151 and a further damping element 114 similar to the damping element 104 of the damping device 100 . the installation tool 200 includes a shaft part 201 , a movable adaptor 202 and a locator element 203 . the shaft part 201 includes an elongate rod 210 with a first end carrying a handle 211 and a second end 212 with an internal thread for cooperation with the threaded portion 51 of the device 100 or of the threaded portion 151 of the damping extension 110 . the movable adaptor 202 includes a locator knob 220 and a hollow threaded body 221 with a collar 222 at one of its ends . the locator knob 220 has a central hole with an internal thread that cooperates with the thread of the body 221 for fine tune adjustment . the collar 222 of the threaded body 221 includes a threaded hole 223 that receives a wing screw 224 for abutting and securing to the rod 210 of the shaft part 201 . the locator element 203 is substantially cuboid in shape with a channel 230 , 231 along an opposed two of its sides . a first channel 230 is configured to receive an outer portion of the shaft 20 of the putter 2 , while the second channel 231 is configured to receive and locate the damping element 104 . in use and with reference to fig1 to 12 , the threaded end 51 of the damping device 100 is secured to the second end 212 of the shaft part 201 of the installation tool 200 . the locator element 203 is then placed at the desired location on the shaft 20 and the damping element 104 is located in the second channel 231 of the locator element and the installation tool 200 is adjusted such that the base of the locator knob 220 abuts the top of the shaft 20 . preferably , the top of the grip on the shaft 20 is removed and it is also envisaged that the kit of the invention may be provided with a cap that may carry a logo or the like . the device 100 is then inserted and forced into position until the bottom of the locator knob 220 abuts the top of the shaft 20 . the wing screw 224 is then loosened and the movable adaptor 202 is pushed up the shaft part 201 and the handle 211 is turned to unscrew the second end 212 from the threaded portion 51 of the device 100 and the installation tool 200 is retracted . it will be appreciated by those skilled in the art that several variations are envisaged without departing from the scope of the invention . for example , the configuration of the device 1 , e . g . the choice of materials and / or geometry of the elements 3 , 4 and / or rod 5 , may be selected to increase the dead weight by more or less than 100 grams , for example by 25 or 35 or 50 grams or even 150 grams or more . additionally or alternatively , the configuration of the device 1 , e . g . the choice of materials and / or geometry and / or position of the device 1 and / or elements 3 , 4 and / or rod 5 , may be selected to move the centre of gravity of the putter 2 if this is required and / or desirable . advantageously , the rod 5 may comprise a composite or carbon fibre material . it will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and / or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein .
a golf club comprising a shaft , a head and a damping device . the damping device includes an anchor element and a damping element interconnected by a rigid rod . the anchor element is anchored within the lower section of the shaft that has a substantially constant diameter such that the damping element is in contact with an internal surface of the shaft to dampen vibrations therein .