GOLF SWING TRAINING DEVICE
United States Patent 3767204
A device for teaching, learning or practicing a correct golf swing comprising: a first member fixedly mounted parallel to and behind a line across the golfer's hips; a sliding member mounted on the first member for sliding along the first member in the direction of the target in response to movement of the golfer's thighs in the downswing; a pivoting member mounted on the sliding member which includes a pair of thigh rests which receive the backs of the golfer's thighs and an adjustable rod which restrains it and the sliding member from sliding toward the target until the golfer's thighs achieve a predetermined amount of pivot in the backswing and thereafter releases it and the sliding member to slide along the first member in response to the lateral movement of the golfer's thighs in the downswing.
US Patent References:
Golf practice device
Hara - July 1956 - 2755091
Hip movement training device for golfers
Sheldon et al. - November 1965 - 3215438
Golfer's head movement restraining device rendered non-restraining at ball impact
Mackniesh - June 1967 - 3325169
Golf practice device
Hara - July 1956 - 2755091
Hip movement training device for golfers
Sheldon et al. - November 1965 - 3215438
Golfer's head movement restraining device rendered non-restraining at ball impact
Mackniesh - June 1967 - 3325169
Application Number:
05/290795
Publication Date:
10/23/1973
Filing Date:
09/21/1972
View Patent Images:
Export Citation:
Primary Class:
International Classes:
A63B69/36; A63B69/00; A63B69/36
Field of Search:
273/183,188,189,190,191,192,187
Primary Examiner:
Marlo, George J.
Claims:
I claim
1. Apparatus for improving a golfer's swing comprising:
2. The apparatus according to claim 1 including:
3. The apparatus according to claim 1 wherein:
4. The apparatus according to claim 1 wherein:
5. The apparatus according to claim 4 wherein:
6. The apparatus according to claim 4 wherein:
7. An apparatus for improving a golfer's swing comprising:
8. The apparatus according to claim 7 wherein:
1. Apparatus for improving a golfer's swing comprising:
2. The apparatus according to claim 1 including:
3. The apparatus according to claim 1 wherein:
4. The apparatus according to claim 1 wherein:
5. The apparatus according to claim 4 wherein:
6. The apparatus according to claim 4 wherein:
7. An apparatus for improving a golfer's swing comprising:
8. The apparatus according to claim 7 wherein:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for teaching, learning and practicing a correct golf swing.
2. Description of the Prior Art
A correct golf swing is a complex series of inter-related movements which is strived for by many but achieved by only few. The motions requried to perform a correct golf swing are not secret--many articles have been written describing them. However the only way for a golfer to master these motions is to first get the "feel" of them and then practice them until they become "grooved" into his or her muscle memory.
The moving parts of the swing--the backswing and downswing--are the hardest to get the "feel" of and "groove" and it is these parts which the beginner and novice golfer usually never master even with repeated lessons and practice. The device of this invention is intended as a teaching and practice aid which will enable a golfer to develop a feel for a proper backswing and downswing and to repeat the same with consistency during practice. Although it also promotes a proper stance this unique device is primarily concerned with maintaining balance throughout the swing, ensuring a full turn by the upper body in the backswing, and forcing the golfer to start the downswing with a lateral slide of the lower part of the target side of the body.
SUMMARY OF THE INVENTION
The novel golf swing aid of this invention is mounted in a fixed position behind the golfer and thus is not a visual ditraction. It has minimum contact with the golfer's body; the only two points of contact being the backs of the golfer's thighs. Therefore it leaves the upper body and arms completely unrestricted during the swing. It operates in response to the pivoting of the thighs (primarily the one farthest from the target) in the backswing and the lateral slide of the thighs toward the target in the downswing. The device is adjustable to the varying degrees of turn required for different shots and thus may be used for practicing shots with all clubs from the driver to the wedge.
The device of this invention comprises four basic parts: a first member mounted in a fixed position generally parallel to and behind a line across the golfer's hips; a sliding member mounted on top of the first member for sliding along the first member in the direction of the target; a pivoting member mounted on the sliding member which pivots in a plane approximately parallel to the plane of the golfer's thighs and has a pair of thigh rests attached to its top and is equipped with means which restrains it and the sliding member from movement toward the target until the golfer's thighs achieve a predetermined amount of pivot in the backswing and thereafter releases it and the sliding member to slide along the first member in response to the lateral slide of the golfer's thighs during the initial part of the downswing.
The entire device is inclined at a downwardly angle such that it promotes a proper stance with the knees flexed. Also, since the thigh rests are aligned in the direction of the target the golfer's stance must be essentially "square" to the target. The golfer "sits" on the device with the backs of the thighs resting firmly on the thigh rests. The thighs must remain in solid contact with the rests during all phases of the swing; otherwise the device will fail to operate. This contact requirement provides the "feel" by which the golfer realizes whether or not the swing is proper. Because the golfer is "seated" on the device the weight is distributed evenly from front to back which promotes proper balance throughout the swing. Since only a predetermined amount of thigh turn during the backswing will release the pivoting member the golfer must make a full backswing before starting into the downswing, and because the device will only slide laterally toward the target the downswing must be initiated by a lateral slide of the lower portion of the target side of the body toward the target.
If used consistently the aid of this invention will enable the golfer to learn to achieve a full body turn in the backswing and return smoothly to the ball using proper leg action. The device prevents the golfer from "hitting from the top," swaying, transferring weight to the toes and not transferring weight to the target side during the downswing. In doing this it promotes proper balance, rhythm and timing.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate a portable model of the golf swing aid of this invention. In these drawings the device is set up for a right-handed swing. The target side is the left side as shown in FIG. 1 and the non-target side is the right side as shown in FIG. 1. Referring to these drawings:
FIG. 1 is an isometric, rear view of the golf swing device of this invention;
FIG. 2A is a miniaturized, front, elevational view of the device of FIG. 1 showing the position and operation of the device during the backswing;
FIG. 2B is a miniaturized, front, elevational view of the device of FIG. 1 showing the position and operation of the device during the downswing;
FIG. 3 is a plan view of the top portion of the device along line 3--3 of FIG. 1;
FIG. 4 is a rear, elevational view of the portion of the device shown in FIG. 3;
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 4; and
FIG. 6 is a partial sectional view taken along line 6--6 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated in FIG. 1, the device is supported on a tripod stand, generally designated 1, comprising legs 2, 3 and 4 and a crossbar 5 between legs 2 and 4. The three legs join at a cylindrical collar 6 with legs 2 and 4 being welded to the outer surface of collar 6 and leg 3 being slidably received within it. Leg 3 has a longitudinal line of holes 7 and collar 6 has a removable pin 8 extending through it in line with holes 7 whereby the height of the device may be adjusted by sliding leg 3 within collar 6 and inserting pin 8 into one of holes 7. A strut 9 extends between leg 3 and the target side of the device to provide further stability.
It is important that base 1 provide a solid support for the device and keep it from wobbling during use. In nonportable models of the device it may be desirable to imbed the tripod legs in the ground or mount the device on a fixed body such as a partition or wall.
Referring to FIG. 1, the stationary member of the device, on which the other members pivot and slide as described above, is elongated channel bar 13 which is mounted on top of collar 6 channel-side down at a downwardly incline which is approximately the incline of the golfer's thighs when the golfer takes his stance (roughly in the range of 25° to 35° to the horizontal). Since the remainder of the device is positioned essentially parallel to bar 13, the entire device is so inclined. Bar 13 is acentrally mounted on collar 6 parallel to a line across the golfer's hips (approximately horizontal) with its long end toward the target. As seen in FIGS. 1, 3 and 4, a sliding member, generally designated 14 is mounted on top of channel bar 13. Sliding member 14 includes a flat plate 15 and lugs 16, 17, 18 and 19 attached at the respective ends of each side thereof. Each of these lugs has a roller 20 journaled within it which rolls against an outer side of one of flanges 21, 22 of channel bar 13 (FIGS. 4, 5) and a second roller 23 mounted at the bottom of its inner side which rolls against the bottom of one of the flanges 21, 22. Rollers 20, 23 enable sliding member 14 to slide smoothly along channel bar 13 with minimum friction. The connecting member (not shown) between strut 9 and the target end of bar 13 acts as a stop to prevent member 14 from sliding off the target end of bar 13. Stud 24 extending up through the non-target end of bar 13 acts as a stop at that end.
A pivoting member, generally designated 25, is attached to the non-target end of the top of plate 15. As illustrated in FIGS. 4 and 5 pivoting member 25 is attached to plate 15 by a shaft 26 and includes a generally cylindrical head 30 rotatably mounted on top of shaft 26 and an elongated flat bar 31 attached to the top of head 30. A pair of thigh rests 32, 33 are attached to the top of bar 31 by brackets 34, 35 respectively. Brackets 34, 35 are constructed to permit the rests to pivot about pins 36, 37 thereof to accommodate the stances of different golfers. Bar 31 is counterweighted with counterweight 38 to balance it when it is in the position as shown in FIG. 1.
Pivoting member 25 is a critical part of the device since it is the member which keeps the device from operating unless triggered by a proper body turn in the backswing. Pivoting member 25 forces the golfer to make a proper body turn because it is constructed to restrain sliding member 14 until the golfer's thighs (which turn with the hips and shoulders) achieve a predetermined degree of turn and then release. When sliding member 14 is restrained the golfer cannot initiate a lateral slide toward the target with the lower part of the target side of the body and thus cannot downswing effectively. Referring to FIG. 6 the means by which this restrain and release are achieved are arm 39 attached horizontally to the rear, non-target side of head 30 substantially parallel to bar 31, threaded bolt 40 which is received through a threaded bore in the non-target end of arm 39 at right angles thereto and stud 24.
The operation of the device is as follows: after its height is adjusted as described above, it is set in the position shown in FIGS. 1, 3 and 4 with sliding member 14 slid all the way to the non-target end of bar 13 and pivoting member 25 horizontal with bolt 40 seated on the non-target side of stud 24. When bolt 40 is so seated, pivoting member 25 and sliding member 14 are restrained from horizontal movement toward the target. The golfer then takes a stance in front of the device fitting the backs of the thighs against thigh rests 32, 33. Rests 32, 33 will pivot about pins 36, 37 somewhat to accommodate the golfer's stance but the golfer's thighs must be firmly seated against the rests with the knees flexed slightly and the back bent forward slightly. The golfer will thus be forced to take an essentially square stance with the weight properly distributed between the heels and balls of the feet ready to begin the backswing.
As the golfer begins the backswing the thighs must remain in contact with the thigh rests 32, 33 in order to cause pivoting member 25 to pivot clockwise as shown by the arrows at the left sides of FIGS. 1 and 3. This is also illustrated in FIG. 2A in which the golfer is approximately at the top of the backswing and pivoting member 25 has turned substantially from horizontal. Referring to FIG. 6 as head 30 of pivoting member 25 (in response to the body turn in the backswing) rotates the shank of bolt 40 will swing clear of stud 24 thereby releasing pivoting member 25 and sliding member 14 to slide along bar 13 in the direction of the target. If the rotation of head 30 is not great enough to swing the shank of bolt 40 clear of stud 24 (which would be caused by a poor turn) member 25 will remain locked in place preventing any sliding of member 14 and pivoting member 25 toward the target. This will prevent the golfer from making an effective downswing and thus abort the swing. The extent to which head 30 must be rotated to release member 25 and member 14 may be varied by changing the position of bolt 40. By tightening it (causing its shank to be moved to the right as seen in FIG. 6) the required extent of rotation may be increased. Such settings of bolt 40 will be used for practicing drives, fairway wood shots and long iron shots. By backing off bolt 40 (moving the shank to the left as seen in FIG. 6) the required extent of rotation may be decreased. These settings will be used for mid-iron and short iron shots.
During the backswing the device also keeps the golfer from swaying away from the target. The golfer cannot sway because the thighs are resting solidly against the thigh rests and pivoting member 25 and sliding member 14 are not capable of sliding away from the target on bar 13 because of stud 24.
Assuming the golfer has made a sufficient body turn in the backswing to release pivoting member 25 (that is the shank of bolt 40 has swung clear of stud 24) the device is in position for the golfer to begin the downswing. As described above the downswing is initiated by a lateral move of the lower target side of the body toward the target while keeping both knees flexed. This movement maintains the coiling and muscle tension in the upper body which ultimately leads to maximum club head speed through the hitting area. It is incorrect to start the downswing with downward movement of the hands and arms--commonly called "hitting from the top". If the golfer initiates the downswing with the hands and arms the leg farthest away from the target will carry the bulk of the golfer's weight causing the knee of that leg to straighten. This will cause the thigh of that leg to lose solid contact with the thigh rest and thus prevent the golfer from sliding pivoting member 25 and sliding member 14 toward the target on bar 13. Only by staying in balance and starting the downswing with a lateral slide of the lower portion of the target side of the body will the proper motion of the device be achieved. Any jerkiness in the downswing caused by initiating the downswing with the hands and arms will be accentuated by the device, thus making this fault quite apparent to the golfer.
If the golfer transfers weight forward to the toes or straightens either knee or both knees at the beginning of the downswing the thighs will lose solid contact with the thigh rests and the sliding of pivoting member 25 and sliding member 14 along bar 13 toward the target will be impaired.
The device also prevents spinning the hips in the downswing. Spinning of the hips is usually a result of hitting from the top or transferring weight to the toes. Since such spinning is led by the hip closest to the target and would take place in a horizontal plane running generally perpendicular to bar 13, bar 13 being in a fixed position will prevent such spinning.
FIG. 2B shows the position of the machine when the golfer's downswing is nearing the hitting area. As illustrated pivoting member 25 has returned to horizontal and has slid substantially toward the target with the vertical axis of the golfer's body well behind the ball. As the downswing continues pivoting member 25 and sliding member 14 will continue to slide toward the target end of the device until the golfer begins the followthrough after hitting the ball.
After the swing is completed sliding member 14 is slid back to the non-target end and the shank of bolt 40 is replaced around the non-target side of stud 24 thereby putting the machine in position to be used again. The golfer may so replace the shank of bolt 40 by merely reaching behind himself or herself and need not step away from the device.
Various modifications may be made to the embodiment described above without affecting its mode of operation or the result achieved thereby. For instance other types of bases which attach to the fixed member of the device at more than one point could be employed. Likewise, in place of the restraint-release means described above, cog or gear mechanisms could be incorporated in the rotating head 30 and a dial on the face of head 30 used to vary the required degree of thigh turn. Also, various spring return devices may be used in place of counterweight 38. Such modifications and others are within ordinary mechanical skill and are intended to be within the scope of the following claims.
1. Field of the Invention
The present invention relates to a device for teaching, learning and practicing a correct golf swing.
2. Description of the Prior Art
A correct golf swing is a complex series of inter-related movements which is strived for by many but achieved by only few. The motions requried to perform a correct golf swing are not secret--many articles have been written describing them. However the only way for a golfer to master these motions is to first get the "feel" of them and then practice them until they become "grooved" into his or her muscle memory.
The moving parts of the swing--the backswing and downswing--are the hardest to get the "feel" of and "groove" and it is these parts which the beginner and novice golfer usually never master even with repeated lessons and practice. The device of this invention is intended as a teaching and practice aid which will enable a golfer to develop a feel for a proper backswing and downswing and to repeat the same with consistency during practice. Although it also promotes a proper stance this unique device is primarily concerned with maintaining balance throughout the swing, ensuring a full turn by the upper body in the backswing, and forcing the golfer to start the downswing with a lateral slide of the lower part of the target side of the body.
SUMMARY OF THE INVENTION
The novel golf swing aid of this invention is mounted in a fixed position behind the golfer and thus is not a visual ditraction. It has minimum contact with the golfer's body; the only two points of contact being the backs of the golfer's thighs. Therefore it leaves the upper body and arms completely unrestricted during the swing. It operates in response to the pivoting of the thighs (primarily the one farthest from the target) in the backswing and the lateral slide of the thighs toward the target in the downswing. The device is adjustable to the varying degrees of turn required for different shots and thus may be used for practicing shots with all clubs from the driver to the wedge.
The device of this invention comprises four basic parts: a first member mounted in a fixed position generally parallel to and behind a line across the golfer's hips; a sliding member mounted on top of the first member for sliding along the first member in the direction of the target; a pivoting member mounted on the sliding member which pivots in a plane approximately parallel to the plane of the golfer's thighs and has a pair of thigh rests attached to its top and is equipped with means which restrains it and the sliding member from movement toward the target until the golfer's thighs achieve a predetermined amount of pivot in the backswing and thereafter releases it and the sliding member to slide along the first member in response to the lateral slide of the golfer's thighs during the initial part of the downswing.
The entire device is inclined at a downwardly angle such that it promotes a proper stance with the knees flexed. Also, since the thigh rests are aligned in the direction of the target the golfer's stance must be essentially "square" to the target. The golfer "sits" on the device with the backs of the thighs resting firmly on the thigh rests. The thighs must remain in solid contact with the rests during all phases of the swing; otherwise the device will fail to operate. This contact requirement provides the "feel" by which the golfer realizes whether or not the swing is proper. Because the golfer is "seated" on the device the weight is distributed evenly from front to back which promotes proper balance throughout the swing. Since only a predetermined amount of thigh turn during the backswing will release the pivoting member the golfer must make a full backswing before starting into the downswing, and because the device will only slide laterally toward the target the downswing must be initiated by a lateral slide of the lower portion of the target side of the body toward the target.
If used consistently the aid of this invention will enable the golfer to learn to achieve a full body turn in the backswing and return smoothly to the ball using proper leg action. The device prevents the golfer from "hitting from the top," swaying, transferring weight to the toes and not transferring weight to the target side during the downswing. In doing this it promotes proper balance, rhythm and timing.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate a portable model of the golf swing aid of this invention. In these drawings the device is set up for a right-handed swing. The target side is the left side as shown in FIG. 1 and the non-target side is the right side as shown in FIG. 1. Referring to these drawings:
FIG. 1 is an isometric, rear view of the golf swing device of this invention;
FIG. 2A is a miniaturized, front, elevational view of the device of FIG. 1 showing the position and operation of the device during the backswing;
FIG. 2B is a miniaturized, front, elevational view of the device of FIG. 1 showing the position and operation of the device during the downswing;
FIG. 3 is a plan view of the top portion of the device along line 3--3 of FIG. 1;
FIG. 4 is a rear, elevational view of the portion of the device shown in FIG. 3;
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 4; and
FIG. 6 is a partial sectional view taken along line 6--6 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated in FIG. 1, the device is supported on a tripod stand, generally designated 1, comprising legs 2, 3 and 4 and a crossbar 5 between legs 2 and 4. The three legs join at a cylindrical collar 6 with legs 2 and 4 being welded to the outer surface of collar 6 and leg 3 being slidably received within it. Leg 3 has a longitudinal line of holes 7 and collar 6 has a removable pin 8 extending through it in line with holes 7 whereby the height of the device may be adjusted by sliding leg 3 within collar 6 and inserting pin 8 into one of holes 7. A strut 9 extends between leg 3 and the target side of the device to provide further stability.
It is important that base 1 provide a solid support for the device and keep it from wobbling during use. In nonportable models of the device it may be desirable to imbed the tripod legs in the ground or mount the device on a fixed body such as a partition or wall.
Referring to FIG. 1, the stationary member of the device, on which the other members pivot and slide as described above, is elongated channel bar 13 which is mounted on top of collar 6 channel-side down at a downwardly incline which is approximately the incline of the golfer's thighs when the golfer takes his stance (roughly in the range of 25° to 35° to the horizontal). Since the remainder of the device is positioned essentially parallel to bar 13, the entire device is so inclined. Bar 13 is acentrally mounted on collar 6 parallel to a line across the golfer's hips (approximately horizontal) with its long end toward the target. As seen in FIGS. 1, 3 and 4, a sliding member, generally designated 14 is mounted on top of channel bar 13. Sliding member 14 includes a flat plate 15 and lugs 16, 17, 18 and 19 attached at the respective ends of each side thereof. Each of these lugs has a roller 20 journaled within it which rolls against an outer side of one of flanges 21, 22 of channel bar 13 (FIGS. 4, 5) and a second roller 23 mounted at the bottom of its inner side which rolls against the bottom of one of the flanges 21, 22. Rollers 20, 23 enable sliding member 14 to slide smoothly along channel bar 13 with minimum friction. The connecting member (not shown) between strut 9 and the target end of bar 13 acts as a stop to prevent member 14 from sliding off the target end of bar 13. Stud 24 extending up through the non-target end of bar 13 acts as a stop at that end.
A pivoting member, generally designated 25, is attached to the non-target end of the top of plate 15. As illustrated in FIGS. 4 and 5 pivoting member 25 is attached to plate 15 by a shaft 26 and includes a generally cylindrical head 30 rotatably mounted on top of shaft 26 and an elongated flat bar 31 attached to the top of head 30. A pair of thigh rests 32, 33 are attached to the top of bar 31 by brackets 34, 35 respectively. Brackets 34, 35 are constructed to permit the rests to pivot about pins 36, 37 thereof to accommodate the stances of different golfers. Bar 31 is counterweighted with counterweight 38 to balance it when it is in the position as shown in FIG. 1.
Pivoting member 25 is a critical part of the device since it is the member which keeps the device from operating unless triggered by a proper body turn in the backswing. Pivoting member 25 forces the golfer to make a proper body turn because it is constructed to restrain sliding member 14 until the golfer's thighs (which turn with the hips and shoulders) achieve a predetermined degree of turn and then release. When sliding member 14 is restrained the golfer cannot initiate a lateral slide toward the target with the lower part of the target side of the body and thus cannot downswing effectively. Referring to FIG. 6 the means by which this restrain and release are achieved are arm 39 attached horizontally to the rear, non-target side of head 30 substantially parallel to bar 31, threaded bolt 40 which is received through a threaded bore in the non-target end of arm 39 at right angles thereto and stud 24.
The operation of the device is as follows: after its height is adjusted as described above, it is set in the position shown in FIGS. 1, 3 and 4 with sliding member 14 slid all the way to the non-target end of bar 13 and pivoting member 25 horizontal with bolt 40 seated on the non-target side of stud 24. When bolt 40 is so seated, pivoting member 25 and sliding member 14 are restrained from horizontal movement toward the target. The golfer then takes a stance in front of the device fitting the backs of the thighs against thigh rests 32, 33. Rests 32, 33 will pivot about pins 36, 37 somewhat to accommodate the golfer's stance but the golfer's thighs must be firmly seated against the rests with the knees flexed slightly and the back bent forward slightly. The golfer will thus be forced to take an essentially square stance with the weight properly distributed between the heels and balls of the feet ready to begin the backswing.
As the golfer begins the backswing the thighs must remain in contact with the thigh rests 32, 33 in order to cause pivoting member 25 to pivot clockwise as shown by the arrows at the left sides of FIGS. 1 and 3. This is also illustrated in FIG. 2A in which the golfer is approximately at the top of the backswing and pivoting member 25 has turned substantially from horizontal. Referring to FIG. 6 as head 30 of pivoting member 25 (in response to the body turn in the backswing) rotates the shank of bolt 40 will swing clear of stud 24 thereby releasing pivoting member 25 and sliding member 14 to slide along bar 13 in the direction of the target. If the rotation of head 30 is not great enough to swing the shank of bolt 40 clear of stud 24 (which would be caused by a poor turn) member 25 will remain locked in place preventing any sliding of member 14 and pivoting member 25 toward the target. This will prevent the golfer from making an effective downswing and thus abort the swing. The extent to which head 30 must be rotated to release member 25 and member 14 may be varied by changing the position of bolt 40. By tightening it (causing its shank to be moved to the right as seen in FIG. 6) the required extent of rotation may be increased. Such settings of bolt 40 will be used for practicing drives, fairway wood shots and long iron shots. By backing off bolt 40 (moving the shank to the left as seen in FIG. 6) the required extent of rotation may be decreased. These settings will be used for mid-iron and short iron shots.
During the backswing the device also keeps the golfer from swaying away from the target. The golfer cannot sway because the thighs are resting solidly against the thigh rests and pivoting member 25 and sliding member 14 are not capable of sliding away from the target on bar 13 because of stud 24.
Assuming the golfer has made a sufficient body turn in the backswing to release pivoting member 25 (that is the shank of bolt 40 has swung clear of stud 24) the device is in position for the golfer to begin the downswing. As described above the downswing is initiated by a lateral move of the lower target side of the body toward the target while keeping both knees flexed. This movement maintains the coiling and muscle tension in the upper body which ultimately leads to maximum club head speed through the hitting area. It is incorrect to start the downswing with downward movement of the hands and arms--commonly called "hitting from the top". If the golfer initiates the downswing with the hands and arms the leg farthest away from the target will carry the bulk of the golfer's weight causing the knee of that leg to straighten. This will cause the thigh of that leg to lose solid contact with the thigh rest and thus prevent the golfer from sliding pivoting member 25 and sliding member 14 toward the target on bar 13. Only by staying in balance and starting the downswing with a lateral slide of the lower portion of the target side of the body will the proper motion of the device be achieved. Any jerkiness in the downswing caused by initiating the downswing with the hands and arms will be accentuated by the device, thus making this fault quite apparent to the golfer.
If the golfer transfers weight forward to the toes or straightens either knee or both knees at the beginning of the downswing the thighs will lose solid contact with the thigh rests and the sliding of pivoting member 25 and sliding member 14 along bar 13 toward the target will be impaired.
The device also prevents spinning the hips in the downswing. Spinning of the hips is usually a result of hitting from the top or transferring weight to the toes. Since such spinning is led by the hip closest to the target and would take place in a horizontal plane running generally perpendicular to bar 13, bar 13 being in a fixed position will prevent such spinning.
FIG. 2B shows the position of the machine when the golfer's downswing is nearing the hitting area. As illustrated pivoting member 25 has returned to horizontal and has slid substantially toward the target with the vertical axis of the golfer's body well behind the ball. As the downswing continues pivoting member 25 and sliding member 14 will continue to slide toward the target end of the device until the golfer begins the followthrough after hitting the ball.
After the swing is completed sliding member 14 is slid back to the non-target end and the shank of bolt 40 is replaced around the non-target side of stud 24 thereby putting the machine in position to be used again. The golfer may so replace the shank of bolt 40 by merely reaching behind himself or herself and need not step away from the device.
Various modifications may be made to the embodiment described above without affecting its mode of operation or the result achieved thereby. For instance other types of bases which attach to the fixed member of the device at more than one point could be employed. Likewise, in place of the restraint-release means described above, cog or gear mechanisms could be incorporated in the rotating head 30 and a dial on the face of head 30 used to vary the required degree of thigh turn. Also, various spring return devices may be used in place of counterweight 38. Such modifications and others are within ordinary mechanical skill and are intended to be within the scope of the following claims.