[ 0044 ] fig1 illustrates an instrumented golf club system 2 comprising an instrumented golf club 10 , an interface mechanism 18 and a computing or data processing means 28 . the instrumented golf club 10 comprises a grip 12 , a shaft 14 , a club head 16 , a first plurality of strain gauges 20 located on the exterior 25 portion of the shaft 14 proximate the butt end 27 , and a second plurality of strain gauges 21 located on the exterior 25 portion of the shaft 14 proximate the tip end 26 , as further described below . data measured by the first plurality of strain gauges 20 and second plurality of strain gauges 21 is transferred from the instrumented golf club 10 to the computing means 28 via the interface mechanism 18 . the interface mechanism 18 comprises a connection plug 18 a and a serial interface device 18 b . the connection plug 18 a has a plurality of pins 19 for connection to a plurality of receptors ( not shown ) within the shaft for electronically communicating data from the instrumented golf club 10 to the data processing means 28 . when connected , the interface mechanism 18 provides external power to the instrumented golf club 10 . the data that is collected by the instrumented golf club 10 is transferred to the computer means via the interface mechanism 18 . the golf club head 16 may be any type of conventional club head since the strain gauges 20 and 21 are located on the shaft 14 . in a preferred embodiment , the club head 16 is composed of composite material such as disclosed in u . s . pat . no . 6 , 248 , 025 , filed on dec . 29 , 1999 , entitled composite golf club head and method of manufacturing , and which pertinent parts are hereby incorporated by reference . however , those skilled in the pertinent art will recognize that other materials , such as titanium , titanium alloys , stainless steel , amorphous metals , persimmon and the like , may be used for the club head without departing from the scope and spirit of the present invention . regardless of the material chosen for the club head , the golf club 10 , when combined with the circuitry and electronic elements , should approximate the weight of a standard golf club . the club head 16 is preferably a driver . however , the club head may be a fairway wood , an iron ( 1 - iron through 9 - iron ), a wedge ( lob , sand , pitching and approach ) or a putter . the shaft 14 may be anywhere from 35 inches for a wedge to 50 inches for a driver , and is preferably composed of a graphite material . however , the shaft may also be composed of steel titanium , or a bi - material . the shaft 14 has a wall 22 that defines a hollow interior 23 . the shaft 14 has an interior surface 24 and an exterior surface 25 . the shaft 14 has a tip end 26 in proximity to the club head 16 and a butt end 27 , opposite the tip end 26 . the shaft 14 also having an opening 31 to the hollow interior 24 located at the butt end 27 . the shaft 14 generally tapers in its diameter from the butt end 27 to the tip end 26 . [ 0049 ] fig2 is a top perspective view of the club head 16 , comprising a top 30 , a heel region 32 , a face 34 , a toe region 36 , a rear region 38 and a ribbon 40 . a right - hand coordinate system is used , and is illustrated by the designation of the x , y and z axes in fig2 . the x axis is oriented vertically ( at address position ) from a soleplate 54 ( as shown in fig3 ) to the top 30 of the club head 16 . the y axis is oriented horizontally ( at address position ) from the toe region 36 to the heel region 32 . the z axis is oriented horizontally ( at address position ) from the face 34 to the rear region 38 . [ 0050 ] fig2 a is an illustration showing a first bending plane 49 , and a second bending plane 51 , wherein , the central axis of the shaft 14 ( not shown ) defines the intersection line of the first bending plane 49 , and the second bending plane 51 . the first bending plane 49 is aligned with the face 34 of the club head 16 , and the second bending plane 51 is at a 90 ° angle , or orthogonal , to the first bending plane 49 . [ 0051 ] fig3 illustrates the golf club shaft 14 of the instrumented golf club system 2 comprising a first plurality of strain gauges 20 consisting of a set of three rosette groups 20 a , 20 b , 20 c ( in phantom ) located on an exterior 25 butt end 27 of the shaft 14 for providing axial and strain measurements during a golf swing . additionally , a second plurality of strain gauges 21 consisting of a set of three rosette groups 21 a , 21 b and 21 c ( not shown ) are shown located on the tip end 26 of the shaft 14 for providing axial and strain measurements during a golf swing . a circuit board 46 is located within the hollow interior 24 of the shaft and is comprised of a memory circuit 48 for storing strain measurements , a power control circuit 50 , a first signal conditioning circuit 52 for the first plurality of strain gauges 20 , a second signal conditioning circuit 54 for the second plurality of strain gauges 21 , and a serial communication circuit 56 . in a preferred embodiment , the circuit board 46 is located approximately 10 ″ down the shaft . however , one skilled in the art would understand that the location of the circuit board 46 is not critical and that placement could be varied to accommodate weight adjustments in different club types . locating the electronics within the shaft helps to further protect the instrumentation from shock loadings that electronics mounted on the club head typically experience upon impact of the golf club with a golf ball . an internal power source 58 is also positioned within the shaft to provide power supply to the circuit board 46 as well as to the first and second plurality of strain gauges 20 and 21 respectively . an led 60 is located on the exterior 25 of the shaft 14 to notify the user that the instrumented golf club system 2 is powered up and to signal upon each successive hit that a triggering event has occurred . [ 0055 ] fig4 is a view of a segment of the instrumented golf club system 2 , as defined by the area iv - iv in fig1 and shows a first plurality of strain gauges 20 . this first plurality of strain gauges are located on the exterior circumference of the shaft at a position proximate the butt end and comprising a set of three rosette groups . the first strain gauge group 20 a , the second strain gauge group 20 b , and the third strain gauge group 20 c ( in phantom ). individual strain gauges are comprised of a triple element having a central axial gauge and right and left crossing shear gauges such that when grouped the nine strain gauges from six wheatstone bridges . a first plurality of wires 62 is used to connect the first plurality of strain gauges 20 to the circuit board 46 . at a triggering event , such as the golfer ” s swing , each strain gauge input receives a signal referred to by a channel numbered ( 0 - 11 ). each channel number references a recorded variable , such as butt bend , butt shear , tip bend and tip shear for each strain gauge . the first plurality of wires 62 connect the individual strain gauge groups 20 a , 20 b and 20 c to the circuit board 46 by first connecting to the circuit board 46 and then running along the interior portion 24 of the golf club shaft 14 , exiting the shaft 14 via an exit hole 100 located below the butt end 26 of the shaft 14 and connecting with the individual sets of strain gauge groups 20 a , 20 b and 20 c located on the exterior 25 butt end 27 of the shaft 14 . the shaft 14 has an opening 64 at the butt end 27 . the shaft 14 has a hollow compartment for placement of a power supply therein , electronic circuitry , sensors , and necessary wiring . a cap 76 is used to cover the hollow compartment of the shaft 14 . in a preferred embodiment , the power supply is a battery tube 78 containing at least a first battery 80 . the battery 80 provides internal power for the instrumented golf club 10 . preferably , a protective casing is located within the shaft 14 for placement of the battery 80 . the shaft electronic circuitry board 46 , which may be one or two boards , includes the internal memory device 134 , a non - volatile buffer memory , a main microprocessor 136 , power control circuitry 120 , signal conditioning circuitry 121 for the strain gauges in the butt end 27 of the shaft 14 , signal conditioning circuitry 122 for the strain gauges in the tip end 26 of the shaft 14 , serial communication circuitry 124 , filter circuitry 126 for the strain gauges , and an analog to digital converter circuitry 128 . the shaft electronic circuitry board 46 is a typical power circuitry board . the placement of all of the electronics in the shaft 14 , as opposed to the club head 16 , allows for the use of multiple club heads 16 in order to analyze a golfer &# 39 ; s swing for different clubs . further , the components in the shaft 14 are modular , and thus are easily replaceable if damaged . such replacement is performed via the opening . a second plurality of strain gauges is also located at the tip end 26 of the golf club shaft 14 . this second plurality of strain gauges 21 are located on the exterior circumference of the tip end of the shaft comprised of a set of three rosette groups being a mirror image of the strain gauges located at the butt end of the shaft . the first strain gauge group 21 a , the second strain gauge group 21 b and the third strain gauge group 21 c . the individual strain gauges are comprised of a triple element having a central axial gauge and right and left crossing shear gauges such that the rosette groups from six wheatstone bridges . a second plurality of wires 63 is used to connect this second plurality of strain gauges 21 to the circuit board 46 . at a triggering event , such as a golfer &# 39 ; s swing , individual strain gauge inputs receive a signal referred to by a channel numbered ( 0 - 11 ). each channel number references a recorded variable , such as butt bend , butt shear , tip bend and tip shear for each strain gauge pair . a second plurality of wires 63 connects the strain gauge groups 21 a , 21 b and 21 c to the circuit board 46 by first connecting to the circuit board 46 and then running along the interior 24 portion of the golf club shaft 14 , exiting the interior 24 of the shaft 14 via a second exit hole ( not shown ) located below the butt end 26 of the shaft 14 and running along the length of the exterior 25 of the shaft 14 to connect with the second plurality of strain gauge sets 21 a , 21 b and 21 c located on the tip end 26 of the shaft . this second plurality of wires 63 connecting the second plurality of strain gauges 21 from the tip end 26 of the golf club shaft 14 are preferably glued to the exterior of the golf club shaft 14 , however , the second plurality of wires 63 may also be affixed to the shaft 14 by any other means including mechanical , that are commonly used in the art . [ 0064 ] fig5 is a view of an individual strain gauge group 20 a as arranged about the circumference of the exterior of the shaft 14 of the instrumented golf club 10 of the present invention . six independent strain gauge elements are needed to make essential measurements in order to calculate the six independent forces and moments . these six individual elements are axial force ( px ), transverse shear forces ( vy ) and ( vz ), bending moments ( my ) and ( mz ) and torsion ( tx ). fig6 is a view of these forces acting upon a typical strain gauge of the present invention . data obtained from the independent forces and moments acting on the shaft at the tip end 26 and butt end 27 are computed from the strain data received via the sets of strain gauges and from the information obtained relative to the shaft stiffness matrix at each location . these stiffness matrices are obtained using experimental or analytical techniques well known in the art . once obtained , the values are entered into the computer program and the data is converted from strains and bends to loads and moments . the relationship between the strain , stiffness and force / moment is illustrated in fig7 . [ 0066 ] fig8 is a flow chart illustrating the steps of operation of the instrumented golf club ( as shown in fig1 ) of the present invention . the entire flow chart is shown in two sections , fig8 a and 8b . prior to initial use it is necessary to load the programming software into the instrumented golf club . first , at step 202 , the computer program is activated at the computer . the club is then connected to the computer via a probe and at step 204 inquiry of the club status is displayed . in the event , as in step 206 , the display indicates that communication between the club and the computer is off - line , the user should verify the connection of the interface mechanism between club and computer . when the status indicates as in step 208 that the communication is on - line , the user should select load round from the club . at step 210 , data is then transferred from the club through the interface to the computer processor . once the data is transferred , at step 212 the engineering menu may be enabled by typing ctr - alt - e . the user will then be asked at step 214 to set the triggering protocol for the club . at step 216 verification of the real time clock is performed and at step 218 , the probe is removed from the club and installation of the battery pack is performed . in fig8 b once the probe has been removed and the battery pack installed , at step 220 an led located on the shaft 14 indicates that the swing analysis program has been activated and that the club has been powered up for use . at step 222 , the led indicates that the program is ready for a triggering . at step 224 , the golfer swings the club . the swinging of the club indicates to the strain gauges that a triggering event has occurred , and at step 226 the led will display the occurrence of this triggering event . at step 228 , the data received by the strain gauges with respect to the bending and shear moments will be stored in a non - volatile rom memory . at step 230 , the user may reconnect the interface mechanism between the instrumented golf club and the computer in order to facilitate the download of information from the club to the computer for processing . at step 232 , data from both the first plurality of strain gauges 20 and the second plurality of strain gauges 21 is downloaded to the processing unit . the processor at step 234 then calculates the six independent forces and moments from the strain gauge measurements . the forces and moments are then used to determine an appropriate shaft flex profile for an individual golfer at step 236 . [ 0074 ] fig9 comprises sample initial data values when the instrumented golf club 10 is in a ready state , before the triggering event of the golf swing and impact with the golf ball has occurred . the top of fig9 indicates the values of the calibration constants at various locations along the shaft used in calculating the values for the data obtained during the collection of the sample data . the first twelve columns indicate the values of the twelve strain gauge channels received from the pairs of strain gauges located either on the tip end or the butt end of the club . the next six columns indicate the calculated values of the six independent forces and moments for the strain gauges located on the butt end of the shaft and the last six columns indicate the calculated values of the six independent forces and moments for the strain gauges located on the tip end of the shaft . [ 0075 ] fig1 and fig1 illustrate sample displays of data collected from a portion of a typical golf swing of the instrumented golf club 10 illustrating the calculated forces and moments both before impact and after impact on the butt end 27 of the shaft 14 ( fig1 ) and tip end 26 of the shaft 14 ( fig1 ). the data is collected from the channels and then converted to values in terms of forces and moments . these forces and moments are displayed in graphical representation and identified as axial force ( px ), bending moments ( mz ) and ( my ), transverse shear forces ( vy ) and ( vz ) and torsion ( tx ). once the raw data is collected , the information can be used to generate information to allow the proper shaft flex to be determined for an individual golfer . it is understood that a person of ordinary skill in the art of computer programming can create a program that will take the raw data , and manipulate the data such that the characteristics of the golf club during the golfer &# 39 ; s swing can be pictorially displayed in a more useful , informative and user friendly manner . this will provide the golfer with useful feedback beyond just the physically measured numerical data . a similar procedure can be used in golf club design , for example , to improve the club head geometry , select materials for the club head or shaft , or help locate weighting material within the club head . furthermore , various tabular , graphical , or other visual formats can be used to display this raw data , including synchronization of the data with a camera for highlighting the golfer &# 39 ; s swing area of maximum club head acceleration , hand rotation and shaft bending stress . in addition , data from an individual golf swing or golf club design can be plotted against golf ball launch data associated with that golf swing or design , so that changes can be suggested to improve distance and accuracy . further , the data may be used to design a golf club that is appropriate for a specific type of golfer , or even for an individual golfer . various shafts may be utilized in the testing to determine which type of shaft may be appropriate for a specific type of golfer . the shafts may vary in length , thickness , flexibility , and the like . one example would have a golfer swing each type of shaft to determine which one was appropriate for that specific type of golfer . various club heads also may be utilized in the testing to determine which type of club head may be appropriate for a specific type of golfer . the club heads may vary in material composition , mass , weight placement ( e . g . center of gravity purposes ), and the like . as above , one example would have a golfer swing each type of club head to determine which one was appropriate for that specific type of golfer . alternatively , the data may be used to determine an appropriate club head for a specific type of golfer . from the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof , and other embodiments illustrated in the accompanying drawings , numerous changes , modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims . therefore , the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims .
a diagnostic golf club system having a diagnostic golf club , an interface means and a computing means is disclosed herein . the diagnostic golf club includes a plurality of sensors , an internal power supply , and a non - volatile memory for capturing data relating to a golf swing . the interface means is capable of transferring data from the diagnostic golf club to the computing means for processing the data and presenting the data in a useful and informative format . the data may be used to determine a shaft flex profile for a particular golfer .