CA1231734A - Swing frequency balancing of golf clubs - Google Patents
Swing frequency balancing of golf clubsInfo
- Publication number
- CA1231734A CA1231734A CA000422500A CA422500A CA1231734A CA 1231734 A CA1231734 A CA 1231734A CA 000422500 A CA000422500 A CA 000422500A CA 422500 A CA422500 A CA 422500A CA 1231734 A CA1231734 A CA 1231734A
- Authority
- CA
- Canada
- Prior art keywords
- frequency
- club
- irons
- woods
- resonant frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
ABSTRACT.
Golf clubs for an individual golfer are provided as a matched set wherein the vibration frequency of the irons are set to a first predetermined common frequency, and that of the woods to a second predetermined common frequency. The preferred swing vibration frequency comprises the natural vibration frequency of a club when the shaft is secured at the normal grip position, so as to simulate the natural vibration mode of the club when being swung by the golfer. In the case of the irons, the preferred frequency normally lies in the range of 280 to 325 cycles per minute (CPM), and in the case of the woods the selected swing vibration frequency normally lies in the range of 250-280 CPM. The determination of the ideal swing vibration frequency for an individual is usually done on a trial basis using a number of club sets wherein each set is matched but unmarked, and selection is made on the basis of personal preference. Alternatively, using the particular club from the players bag for which a strong preferences is expressed, the swing vibration frequency thereof is measured, and the other clubs frequency balanced thereto, for the irons and for the woods, the frequency for the irons being held to an accuracy of about 2 cycles per minute, similarly for the woods.
Golf clubs for an individual golfer are provided as a matched set wherein the vibration frequency of the irons are set to a first predetermined common frequency, and that of the woods to a second predetermined common frequency. The preferred swing vibration frequency comprises the natural vibration frequency of a club when the shaft is secured at the normal grip position, so as to simulate the natural vibration mode of the club when being swung by the golfer. In the case of the irons, the preferred frequency normally lies in the range of 280 to 325 cycles per minute (CPM), and in the case of the woods the selected swing vibration frequency normally lies in the range of 250-280 CPM. The determination of the ideal swing vibration frequency for an individual is usually done on a trial basis using a number of club sets wherein each set is matched but unmarked, and selection is made on the basis of personal preference. Alternatively, using the particular club from the players bag for which a strong preferences is expressed, the swing vibration frequency thereof is measured, and the other clubs frequency balanced thereto, for the irons and for the woods, the frequency for the irons being held to an accuracy of about 2 cycles per minute, similarly for the woods.
Description
~23~73~
This invention is directed to methods of selecting a preferred golf club swing vibration frequency for an indi-vidual, and balancing the clubs of the set to that frequency;
and to the thus matched set of clubs.
Much effort and ingenuity has been directed to impro-ving the game of golf, and one dominant area has been the quality and kind of irons and woods used.
United States patent N0.~,070,022 Braly, Jan.24th,1978 teaches a method of providing a set of clubs wherein`the f're-quency of vibration of each of the shafts per se is controlled by selection, such that for a given club number the predetermined shaft frequency will be in accord with a predetermined chart wherein the plot of shaft frequency with shaft length conforms with a straight line graph having a selected gradient. The determination of frequency of vibration for each shaft involves the substitution of a standard predetermined test weight for the club head~ securing the club by the remoted shaft end, and oscillating the weighted end.
Braly then teaches the provision of classified club heads having a predetermined weight-to-club number gradient, for attachment to his frequency selected sha~ts.
The resultant set of gradient matched clubs obtained by this process of controlling shaft frequency and head weights in predetermined linear gradient relationships generally provides a set of irons or woods varying in swing vibration frequency by about 40 cycles per minute.
British Patent N0.1286255 August 23rd,1972 Kilshaw teaches a method of mathmatically matching golf clubs to a common frequency. However, in practice, as taught by Kilshaw at Page ~ line 55, practical testing demonstrated an accuracy of plus or minus 3 to 5 percent, giving a variation in frequency somewhere between 18 and 30 cycles per minute.
~231 73~
In accordance with the presen-t invention it has been discovered that as the individual player and his or her clubs constituted a functioning combination, it is necessary to determine an optimum relationship between the individual swing and the swing vibration characteristics of his or her clubs.
Accordingly, this necessitated measuring the only determinable portion of the human/club system equation, namely the vibra~tion frequency of the club, taken in the mode in which it is used, by determining natural frequency of oscillational vibration in the as-gripped condition, (i.e. the swing vibration frequency).
To that end, based on the grip generally practiced by most players, a zone of the shaft 3" from the shaft end is selected as the grip point, and club frequency is measured on that basis, with the club clamped at that point.
It will be understood that there is no formula to offer the public, in attempting to systematize anything as subjective as a golfer and his clubs. However, it is felt that certain discussions of the facts and factors involved will at least clarify some of the problem to be solved.
It is postulated that for an average golfer the difference between success enjoyed with his "best" club and the less successful use of other clubs, including his "worst" club arises at least in part due -to the relative attitude of the club-face as it impacts the ball. Presuming that the ball is cor-rectly addressed by the club face, prior to initiating the back-swing, and assuming that the golfer will achieve with practice a certain statistical repeatability of swing, then the primary factor which would consistently create change in the dynamics of the system during the approximately 115 of a second of the down swing might well be elastic deformation and recovery of the club under the swing acceleration forces.
It is noteworthy that the time of swing, of about 1/5 of a second, is the cycle time for a 300 CPM periodici-ty.
3~73~
Standard production golf clubs have variation in the natural frequency of the club set of about 20-50CPM, and in the Braly system the variation in club frequency is systematized.
In the case of Kilshaw the variation is about 18 to 30 CPM.
A large number of ~tests have been carried out using clubs manufactured to a 1 CPM accuracy, wherein it was found that after using a number of "blind" clubs of a frequency unknown to the player~ about 80% of the players tested would pick for themselves a preferred "set" wherein the frequencies for the individual clubs would be within a range of about 5 CPM.
By arbitrarily selecting a frequency from this much narrowed range of frequencies, in as ra-tional a fashion as possible, and balancing all of the assembled irons to within about one cycle per minute of the selected irons frequency it has been found that a consistent improvement in handling has been commonly experienced. In the case of the woods a lower value of swing frequency results. It must be said that any thing which focusses the attention of the golfer, particularly something which appears scientifically based will doubtless have a beneficial influence to a noticeable extent, due to the subjectivity of the situation. However, the extent of improve-ment, and the duration for which the improvements have been noted in making use of uniform matched clubs appears to indicate a more-than-subjective result is present in using the uniformly matched clubs balanced to a single swing frequency in accordance with the present invention.
It is to be noted that the physics of the "swing" of a golf club also involves the weight of the club head, which brings into play the practice of "weighting", wherein the mass of the club head is adjusted by applica-tion of additional weight, sometines to the head, as by taping, or the insertion of additional weights within the shaft. This again is a subjective matter, to the preference of the individual player. It will be understood that in controlling club frequency, a change in club ~3~L734 weighting has some effect on the true club frequency.
A further variable factor which affects the frequency of a club is that of shaft characteristic both as to stiffness and point of flexure.
It will be understood that in order to practice the teachings of the present invention it is necessary to be using a club shaft having the capability of yielding the desired club swing frequency. It may be that shafts that are too stiff or too flexible cannot be brought within the desired club swing-frequency characteristic.
It is to be further noted that the balancing of all of the clubs to a selected frequency is further complicated by the fact that the length of iron clubs generally vary inversely with the number of the club, in order of one half inch(~") per numbered club.
The method herein disclosed provides a frequency adjusting proceedure wherein the effects of shaft length variation are duly allowed for, and a comparatively rapid balancing proceedure is made available, The plus or minus 1 CPM
accuracy permitting the achievement of frequency variation as low as 2 CPM.
The present invention employs a machine for rapidly and accurately deter~ning the swing frequency of a club, thereby permitting rapid and accurate frequency adjustment of individual ones of a set of clubs to a predetermined frequency, or frequencies. This frequency measurirg device is common in the art and does not form part of the present invention.
The present invention thus provides a method a measuring the swing frequency of a golf club having a head and a shaft, comprising the steps of securing the club in a fixture adjacent the end of the shaft remote from the headl having the fixture located along the shaft a predetermined distance from the head commensurate with the usual length of a standard shaft, q~3173~
less the space required for the hand grip of a user, displacing the club head from the neutral axis of the shaft, and releasing the head so as to vibrate the club at the natural frequency of the club, and measuring the frequency of club vibration as the swing frequency.
Having measured the swing frequency in the fashion indicated, the swing frequency of the elub is adjusted, by the steps of removing the club head, reducing the length of the shaft by removing a shaft p-ortion abutting the head, re-attaching the head, repositioning the shaft in the holding fixture to provide the predetermined extent of shaft projection as formerly, and re-measuring the frequency.
It will be understood that in order to practice the method it is necessary to commence with an over-length shaft, having a portion of the shaft handle end projecting beyond the clamping device, whereby the club may be selectively stiffened by shortening the relative length of the more flexible, thinner lower end, until such time as the desired frequency is achieved.
In order to minimize errors in frequency determination it is best that compensating weights for the appropriate swing weight for the finished club is always present. Usually, these weights are within the shaft end, and their presence exerts a certain effect on the value of club swing frequency.
In carrying out an operation upon a club in order to achieve a predetermined frequency with the accumulation of experience it is found -that approximate frequency change effect per unit length of shaft shortening becomes known, and according-ly, in order to achieve a predetermined frequency change, the necessary shaft shortening can be approximately calculated, thereby reducing the number of operations necessary to complete the desired frequency adjustment.
A golf club swing frequency measuring device is pro-vided having a clamp to receive a handle portion of the club in ~23~73~
secured relation therein, and frequency measuring means~for measuring a club lateral oscillation mode having a frequency in the range of about 200 to 400 CPM
The frequency measuring device which has been found satisfactory comprises an infra red light source directed towards the club shaft, with a light`receiver positioned to receive the infra red light from the source, as modulated by thé club shaft, when oscillating.
One embodiment is arranged wherein a beam of light crosses above the shaft, when at rest, whereby the light beam is broken as the shaft vibrates. The beam detector includes means for measuring the time betweenl light ~lses~ which is inverted so as to provide a read-out as shaft frequency.
An alternative embodiment is provided wherein the light beam is reflected by the convex shaft surface, so that the receiver receives a pulsating beam as the shaft oscillates at its natural frequency, each time the shaft passes through the null position. Again~ these light pulses are timed and inverted to provide a read out of shaft frequency.
Certain embodiments of the invention are described, reference being made to the accompanying drawings, wherein;
Figure 1 is a schematic general view showing the subject frequency measuring device, and Figure 2 illustrates three types of club head.
Referring to Figure 1 the arrangement 10 includes an adjustable mounting clamp 12 by means of which a club 14 may be suspended by handle portion 16. The distance from the clamp 12 to the club head comprises the regulation length for the desired club, less the approximately 3 inches of upper handle length where the players hand grip would extend to. The frequency detector 18 has an infra red lamp 20 sending a beam across the top (or bottom) of the shaft, to a receiver 22.
Electrical output from the receiver 22 passes to time measuring device 24, which includes an inverter, the output of which ~L23~734 corresponds to club frequency, and is connected to digital read out display 26.
The display 26 thus provides a direc-t read out of club frequency, in terms of cycles per minute. ~
Referring to Figure 2, it will be seen that club type 30 is for a unitised shaft7 having a weight 32 therein for compensating the club swing weight. Club 34 has an over hosel shaft, again with swing compensa-ting weight 36.
The tapered shaft head 38 is no-t well adapted for practicing the presen-t invention, since the small end of a tapered shaft cannot be cut to adjust the frequency of the club.
The equipment in accordance with the present invention permits frequency balancing to about 0.4% or one CPM accuracy at a nominal frequency of 300 CPM, which is a typical midrange figure for irons.
This 1 CPM variation is in contrast with the more usual range of frequency~-v~r-a-~io~of 20-50CPM for most makes of standard irons.
The results achieved by a great many golfers are very gratifying, acknowledging the subjective nature of the end product, i.e. the plàyer and his/her player-matched clubs.
A most important aspect of the present invention is the capability of manufacturing a replacement club to duplicate a known original, the replacement having a substantially identical club, having the same swing frequency as that of the club being replaced, without need of making reference physically to the original club. Thus, given the swing weight, shaft characteristic and swing frequency for an original club, the club can be substantially precisely duplicated elsewhere.
Accordingly, the present invention. by providing a method for accurately manufacturing individual clubs to a predetermined swing frequency, makes it economically.reasonable to provide sets of test clubs for "blind" testing individual players, to accurately determine the particular swing frequency that appears best suited to the specified individual. Upon ~23~73~
making this subjective determination, the present invention further provides -the capability of economically and accurately manufacturing a set of clubs tailored to the requirements of the individual in terms of respective shaft lengths and swing weights, and having substantially ~the same predetermined swing frequency for each of the iron clubsj and substantially the same (lower) predetermined swing frequency for each of the wood cl~bs.
This invention is directed to methods of selecting a preferred golf club swing vibration frequency for an indi-vidual, and balancing the clubs of the set to that frequency;
and to the thus matched set of clubs.
Much effort and ingenuity has been directed to impro-ving the game of golf, and one dominant area has been the quality and kind of irons and woods used.
United States patent N0.~,070,022 Braly, Jan.24th,1978 teaches a method of providing a set of clubs wherein`the f're-quency of vibration of each of the shafts per se is controlled by selection, such that for a given club number the predetermined shaft frequency will be in accord with a predetermined chart wherein the plot of shaft frequency with shaft length conforms with a straight line graph having a selected gradient. The determination of frequency of vibration for each shaft involves the substitution of a standard predetermined test weight for the club head~ securing the club by the remoted shaft end, and oscillating the weighted end.
Braly then teaches the provision of classified club heads having a predetermined weight-to-club number gradient, for attachment to his frequency selected sha~ts.
The resultant set of gradient matched clubs obtained by this process of controlling shaft frequency and head weights in predetermined linear gradient relationships generally provides a set of irons or woods varying in swing vibration frequency by about 40 cycles per minute.
British Patent N0.1286255 August 23rd,1972 Kilshaw teaches a method of mathmatically matching golf clubs to a common frequency. However, in practice, as taught by Kilshaw at Page ~ line 55, practical testing demonstrated an accuracy of plus or minus 3 to 5 percent, giving a variation in frequency somewhere between 18 and 30 cycles per minute.
~231 73~
In accordance with the presen-t invention it has been discovered that as the individual player and his or her clubs constituted a functioning combination, it is necessary to determine an optimum relationship between the individual swing and the swing vibration characteristics of his or her clubs.
Accordingly, this necessitated measuring the only determinable portion of the human/club system equation, namely the vibra~tion frequency of the club, taken in the mode in which it is used, by determining natural frequency of oscillational vibration in the as-gripped condition, (i.e. the swing vibration frequency).
To that end, based on the grip generally practiced by most players, a zone of the shaft 3" from the shaft end is selected as the grip point, and club frequency is measured on that basis, with the club clamped at that point.
It will be understood that there is no formula to offer the public, in attempting to systematize anything as subjective as a golfer and his clubs. However, it is felt that certain discussions of the facts and factors involved will at least clarify some of the problem to be solved.
It is postulated that for an average golfer the difference between success enjoyed with his "best" club and the less successful use of other clubs, including his "worst" club arises at least in part due -to the relative attitude of the club-face as it impacts the ball. Presuming that the ball is cor-rectly addressed by the club face, prior to initiating the back-swing, and assuming that the golfer will achieve with practice a certain statistical repeatability of swing, then the primary factor which would consistently create change in the dynamics of the system during the approximately 115 of a second of the down swing might well be elastic deformation and recovery of the club under the swing acceleration forces.
It is noteworthy that the time of swing, of about 1/5 of a second, is the cycle time for a 300 CPM periodici-ty.
3~73~
Standard production golf clubs have variation in the natural frequency of the club set of about 20-50CPM, and in the Braly system the variation in club frequency is systematized.
In the case of Kilshaw the variation is about 18 to 30 CPM.
A large number of ~tests have been carried out using clubs manufactured to a 1 CPM accuracy, wherein it was found that after using a number of "blind" clubs of a frequency unknown to the player~ about 80% of the players tested would pick for themselves a preferred "set" wherein the frequencies for the individual clubs would be within a range of about 5 CPM.
By arbitrarily selecting a frequency from this much narrowed range of frequencies, in as ra-tional a fashion as possible, and balancing all of the assembled irons to within about one cycle per minute of the selected irons frequency it has been found that a consistent improvement in handling has been commonly experienced. In the case of the woods a lower value of swing frequency results. It must be said that any thing which focusses the attention of the golfer, particularly something which appears scientifically based will doubtless have a beneficial influence to a noticeable extent, due to the subjectivity of the situation. However, the extent of improve-ment, and the duration for which the improvements have been noted in making use of uniform matched clubs appears to indicate a more-than-subjective result is present in using the uniformly matched clubs balanced to a single swing frequency in accordance with the present invention.
It is to be noted that the physics of the "swing" of a golf club also involves the weight of the club head, which brings into play the practice of "weighting", wherein the mass of the club head is adjusted by applica-tion of additional weight, sometines to the head, as by taping, or the insertion of additional weights within the shaft. This again is a subjective matter, to the preference of the individual player. It will be understood that in controlling club frequency, a change in club ~3~L734 weighting has some effect on the true club frequency.
A further variable factor which affects the frequency of a club is that of shaft characteristic both as to stiffness and point of flexure.
It will be understood that in order to practice the teachings of the present invention it is necessary to be using a club shaft having the capability of yielding the desired club swing frequency. It may be that shafts that are too stiff or too flexible cannot be brought within the desired club swing-frequency characteristic.
It is to be further noted that the balancing of all of the clubs to a selected frequency is further complicated by the fact that the length of iron clubs generally vary inversely with the number of the club, in order of one half inch(~") per numbered club.
The method herein disclosed provides a frequency adjusting proceedure wherein the effects of shaft length variation are duly allowed for, and a comparatively rapid balancing proceedure is made available, The plus or minus 1 CPM
accuracy permitting the achievement of frequency variation as low as 2 CPM.
The present invention employs a machine for rapidly and accurately deter~ning the swing frequency of a club, thereby permitting rapid and accurate frequency adjustment of individual ones of a set of clubs to a predetermined frequency, or frequencies. This frequency measurirg device is common in the art and does not form part of the present invention.
The present invention thus provides a method a measuring the swing frequency of a golf club having a head and a shaft, comprising the steps of securing the club in a fixture adjacent the end of the shaft remote from the headl having the fixture located along the shaft a predetermined distance from the head commensurate with the usual length of a standard shaft, q~3173~
less the space required for the hand grip of a user, displacing the club head from the neutral axis of the shaft, and releasing the head so as to vibrate the club at the natural frequency of the club, and measuring the frequency of club vibration as the swing frequency.
Having measured the swing frequency in the fashion indicated, the swing frequency of the elub is adjusted, by the steps of removing the club head, reducing the length of the shaft by removing a shaft p-ortion abutting the head, re-attaching the head, repositioning the shaft in the holding fixture to provide the predetermined extent of shaft projection as formerly, and re-measuring the frequency.
It will be understood that in order to practice the method it is necessary to commence with an over-length shaft, having a portion of the shaft handle end projecting beyond the clamping device, whereby the club may be selectively stiffened by shortening the relative length of the more flexible, thinner lower end, until such time as the desired frequency is achieved.
In order to minimize errors in frequency determination it is best that compensating weights for the appropriate swing weight for the finished club is always present. Usually, these weights are within the shaft end, and their presence exerts a certain effect on the value of club swing frequency.
In carrying out an operation upon a club in order to achieve a predetermined frequency with the accumulation of experience it is found -that approximate frequency change effect per unit length of shaft shortening becomes known, and according-ly, in order to achieve a predetermined frequency change, the necessary shaft shortening can be approximately calculated, thereby reducing the number of operations necessary to complete the desired frequency adjustment.
A golf club swing frequency measuring device is pro-vided having a clamp to receive a handle portion of the club in ~23~73~
secured relation therein, and frequency measuring means~for measuring a club lateral oscillation mode having a frequency in the range of about 200 to 400 CPM
The frequency measuring device which has been found satisfactory comprises an infra red light source directed towards the club shaft, with a light`receiver positioned to receive the infra red light from the source, as modulated by thé club shaft, when oscillating.
One embodiment is arranged wherein a beam of light crosses above the shaft, when at rest, whereby the light beam is broken as the shaft vibrates. The beam detector includes means for measuring the time betweenl light ~lses~ which is inverted so as to provide a read-out as shaft frequency.
An alternative embodiment is provided wherein the light beam is reflected by the convex shaft surface, so that the receiver receives a pulsating beam as the shaft oscillates at its natural frequency, each time the shaft passes through the null position. Again~ these light pulses are timed and inverted to provide a read out of shaft frequency.
Certain embodiments of the invention are described, reference being made to the accompanying drawings, wherein;
Figure 1 is a schematic general view showing the subject frequency measuring device, and Figure 2 illustrates three types of club head.
Referring to Figure 1 the arrangement 10 includes an adjustable mounting clamp 12 by means of which a club 14 may be suspended by handle portion 16. The distance from the clamp 12 to the club head comprises the regulation length for the desired club, less the approximately 3 inches of upper handle length where the players hand grip would extend to. The frequency detector 18 has an infra red lamp 20 sending a beam across the top (or bottom) of the shaft, to a receiver 22.
Electrical output from the receiver 22 passes to time measuring device 24, which includes an inverter, the output of which ~L23~734 corresponds to club frequency, and is connected to digital read out display 26.
The display 26 thus provides a direc-t read out of club frequency, in terms of cycles per minute. ~
Referring to Figure 2, it will be seen that club type 30 is for a unitised shaft7 having a weight 32 therein for compensating the club swing weight. Club 34 has an over hosel shaft, again with swing compensa-ting weight 36.
The tapered shaft head 38 is no-t well adapted for practicing the presen-t invention, since the small end of a tapered shaft cannot be cut to adjust the frequency of the club.
The equipment in accordance with the present invention permits frequency balancing to about 0.4% or one CPM accuracy at a nominal frequency of 300 CPM, which is a typical midrange figure for irons.
This 1 CPM variation is in contrast with the more usual range of frequency~-v~r-a-~io~of 20-50CPM for most makes of standard irons.
The results achieved by a great many golfers are very gratifying, acknowledging the subjective nature of the end product, i.e. the plàyer and his/her player-matched clubs.
A most important aspect of the present invention is the capability of manufacturing a replacement club to duplicate a known original, the replacement having a substantially identical club, having the same swing frequency as that of the club being replaced, without need of making reference physically to the original club. Thus, given the swing weight, shaft characteristic and swing frequency for an original club, the club can be substantially precisely duplicated elsewhere.
Accordingly, the present invention. by providing a method for accurately manufacturing individual clubs to a predetermined swing frequency, makes it economically.reasonable to provide sets of test clubs for "blind" testing individual players, to accurately determine the particular swing frequency that appears best suited to the specified individual. Upon ~23~73~
making this subjective determination, the present invention further provides -the capability of economically and accurately manufacturing a set of clubs tailored to the requirements of the individual in terms of respective shaft lengths and swing weights, and having substantially ~the same predetermined swing frequency for each of the iron clubsj and substantially the same (lower) predetermined swing frequency for each of the wood cl~bs.
Claims (5)
1. A matched set of golf clubs selected from the group of at least 3 irons or at least 2 woods, each club in said set having a different club head weight and a club length progressively shorter with increasing head weight, the resonant frequency of each said club being within 0.4% of a preselected resonant frequency for said set of golf clubs when physically measured by a frequency measuring instrument.
2. A matched set of golf clubs as defined in claim 1 wherein said set comprises at least 3 irons and said preselected resonant frequency is in the range of 280 to 325 cycles per minute, measured when each said club is clamped 3 inches from its handle end.
3. A matched set of golf clubs as defined in claim 1 wherein said set comprises at least 2 woods and said preselected resonant frequency is in the range of 250 to 280 cycles per minute, measured when each said club is clamped 3 inches from the handle end.
4. A method of providing a golfer with a set of golf clubs composed of at least 3 irons having a preselected resonant frequency matched with the golfer comprising, subjecting said golfer to a "blind" test using irons of different resonant frequencies to select from said irons of different resonant frequencies an iron thereby to determine said preselected resonant frequency, individually matching the resonant frequency of each of said at least 3 irons of said set within 0.4% of said preselected resonant frequency by individually testing the frequency of each iron of said set and adjusting its frequency until the measured frequency of each said iron of said set is within 0.4% of said preselected resonant frequency when physically measured by a frequency measuring instrument.
5. A method of providing a golfer with a set of golf clubs composed of at least 2 woods having a preselected resonant frequency matched with the golfer comprising, subjecting said golfer to a "blind" test using woods of different resonant frequencies to select from said woods of different resonant frequencies an wood thereby to determine said preselected resonant frequency, individually matching the resonant frequency of each of said at least 2 woods of said set within 0.4% of said preselected resonant frequency by individually testing the frequency of each wood of said set and adjusting its frequency until the measured frequency of each said wood of said set is within 0.4% of said preselected resonant frequency when physically measured by a frequency measuring instrument.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US35472082A | 1982-03-04 | 1982-03-04 | |
| US06/354/720 | 1982-03-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1231734A true CA1231734A (en) | 1988-01-19 |
Family
ID=23394632
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000422500A Expired CA1231734A (en) | 1982-03-04 | 1983-02-28 | Swing frequency balancing of golf clubs |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1231734A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7886572B2 (en) | 2006-02-23 | 2011-02-15 | Harpham Neil A | Method for calibrating a backlash impulse device in a sport implement |
-
1983
- 1983-02-28 CA CA000422500A patent/CA1231734A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7886572B2 (en) | 2006-02-23 | 2011-02-15 | Harpham Neil A | Method for calibrating a backlash impulse device in a sport implement |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5879241A (en) | Matched set of golf clubs and method of producing the same | |
| US4070022A (en) | Matched golf shafts and clubs | |
| US4674324A (en) | Golf club swing-weighting method | |
| US6719648B1 (en) | Precise fit golf club fitting system and golf shaft selection methods and apparatus | |
| US5616832A (en) | System and method for evaluation of dynamics of golf clubs | |
| US5318296A (en) | Matched sets for golf clubs having maximum effective moment of inertia | |
| CA1277967C (en) | Calculator for determining frequency matched set of golf clubs | |
| CA1317751C (en) | Method for producing frequency matched sets of composite golf club shafts | |
| US7758446B2 (en) | Golf club shaft tuner | |
| US7056225B1 (en) | Method of making a single flex matched set of golf clubs | |
| US4954198A (en) | Method of fabricating golf clubs and assembly of tubes for forming clubs obtained by the method | |
| Hocknell et al. | Engineering ‘feel’in the design of golf clubs | |
| US4090711A (en) | Golf club shafts including vibratory means | |
| US5608160A (en) | Balancing golf clubs to a common period of oscillation by balancing such clubs to a common equivalent pendulum length | |
| EP0166561A2 (en) | Games racket | |
| US4634124A (en) | Vibration damped sports racquet | |
| CA1231734A (en) | Swing frequency balancing of golf clubs | |
| US5722899A (en) | Method for making a matched set of golf clubs utilizing frequency conversion values | |
| US5763770A (en) | Design of golf clubs with node line mapping | |
| US5417108A (en) | Method for dynamically balancing golf clubs on a conventional swing weight scale using radius of gyration as the controlling parameter | |
| CA2370802A1 (en) | System for optimization of golf clubs | |
| US5792946A (en) | Pendulum length balancing of golf clubs including graphite shafted golf clubs | |
| JP2020075120A (en) | Device for adjusting series of golf clubs and series of golf clubs thus adjusted | |
| US4599898A (en) | Method and apparatus for testing ball striking rackets | |
| US4635935A (en) | Audible-physical coordination racket |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |