US 1983920 A
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Dec. 1l, 1934. D, w. PERIN GOLF SWING DEVICE y Filed Jan. 6, 1932 2 Sheets-Sheet l llnllll lill .l l
\ Dec. 11, 1934. D. w, PERIN GOLF SWING DEVICE Filed Jan. 6, 1932 2 Sheets-Sheet 2 i omi MP5? @Wl Patented Dec. 11, 1934 UNITED STATE-S .PATENT OFFICE GOLF 4SWING DEVICE Application January 6,
This invention relates to a golf swing device and has for its primary object to control `the 'completemovement of A,the entire golf `club, ythereby teaching a person using .the device how the `5 proper golf swing feels, and enabling him, through repetition and practice, to acquire a muscle memory of 'the Swing, without -conscious attention to the theory on :his part.
Another object is to make such a device, that will .completely -govern all the movements of the `golf club, without interfering with the fgrip on the `shaft of lthe club, Aor with the yperson .fusing it, :and without interfering with any of the necessary :movements of his body.
A further -object is to :provide means for fad- ,justing such a device, so that it can maintain Ythe corr-.ect swing for persons :of different .sizes with varying `ratios :of length of arms to height etc.; lso that ggolf clubs :of varying lengths and varying angles :between the head and shaft of 'the club vcan be used therein, whereby any person may try out the feeling `of the correct swing Awith Aseveral diiferent designs lof clubs, fand lthus determine the kind .of lclub best suited lto his individuality.
'Other :objects and advantages Awill appear from the .drawings and specifications.
The purpose of fany golf swing, or stroke, -is to apply .the 4.power of the body through y:the 'club v to :the rball in such imanner that the rball will move along -the desired path in space. To accomplish this itis necessary `to have the 'face of the .club .meet the ball `:at predetermined tangles, both verticaland shorizontal, with the horizontal 'projection `of the line rof lmovement .of the ball and :thus determine the :point of contact between 'the ball .and the iclu'b. It is also ynecessary .to have the point on the :face of ,the club which contacts .the ball, moving in a `predetermined. 40 `direction during )contact with v.the .ball and at a -velocity ywhich determines the :length `of the .de- .sired path in lspace along `which the ball :is .to travel.
All the .forces which can be .appliedto the club :to move it, Yare applied 'through vthe hands of the player, and in all correct golf swings, .can 'tbe Aresolved -into :the .following separate forces, first, a force tending to produce Vrotation .ofthe `*club .shaft axially, second, :a force-:tending to produce rotationof the rclub shaft :radiallyabout .an axis which itself Vtravels Ain a'path to describe apart of a :cylindrical Asurface las the swing progresses, third, .ya force tending to produce rota- .fticn vof .the club shaft -radially :about :an axis which 4always lies in a jplane vperpendicular :to
1932, Serial No. 585,011
ythis cylindrical .surface and which is at all times equidistant from the axis of this surface, .and fourth, a force tending to move the first-named axis .in its cylindrical path. This first-named axis is called the pivot axis of the wrists, the second-named axis yis called the shaft-.angle faxis, and the lpoint where the axis of the club vshaft .cuts Ythe .cylindrical surface is called .the pivot point of the wrists .and moves in an arc .called its arc of travel.
These forces vare called into play in all golf swings land, when analyzed, it will appear that the only differences between the longest swing, such as the drive, .and the shortestfstrokesVsuch as the putt, or chip, are changes in .the amount 1 5 .of travel .both backward and forward .of the .pivot point along its arc of swing, changes in the angles of inclination .of the planes of .the swings with the ground, and` changes in .the .amounts of rotations of the shaft, as well `as :20 changes in lthe positions of the pivot point along its arc of travel at which these rotations occur.
In the .drawings herewith, I have illustrated the `device as applied vto teaching the putting stroke. In .putting the planeof the swingis per- .25 `pendicular .to .the ground or, in other words, .the .a-xis of the cylindrical surface is parallel to the ground, the pivot pointhas no ,movement on ,the backswing, the axial rotation of the club shaft ,is ,entirely prevented, the -radial rotation of the :3.0 shaft about the shaft-.angle .axis is prevented, and ythe radial rotation vof the club shaft about Ythe pivot axis .is controlled according to the posi- .tion of the pivotpoint in its arc of travel. Although the drawingsillustrate .a mechanism es- 35 ,pecially adapted to the teaching of the putting stroke, I do not limit myself to this stroke only, Yand while theillustration chosen shows certainrof the possible movements of the club limited, vand others .entirely prevented, all of the possible .40 movements of .the club necessary to the proper .Swing are nevertheless thereby completely controlled and kept in their proper relationships relative to each other, and this illustration covers broadly all of the necessary conditions dis- 45 closed above.
In the drawings;
Fig. 1 shows a side yview of the device embodying one form of this invention with the club in the position assumed at the start of the stroke;
Fig. 2 shows a view of such device as faced by the player, dot and dash lines being employed :to show the arc Aalong which the pivot lpoint of the wrists moves, together with its center line perpendicular to the ground. The solid lines 55 show the device at the beginning of the putting stroke, and the dotted lines show the positions assumed by the moving parts of the device after the pivot axis has progressed on its arc of travel far enough to have the club shaft lie in a plane perpendicular to the ground; and
Fig. 3 is an enlarged section on the line 3 3 of Fig. 1.
The frame of the `device comprises a base l, preferably a casting, and two upright members 2 2. Hinged to the upright members 2 2 are the two telescoping arms 3 3 with horizontal parallel axes 4 4. The length of these arms may be adjusted by set screws 5 5 and the lower ends are connected by a member orv connecting rod 6 having a vertically extendible portion '7 and hinged on horizontal axes 8 8 parallel to the axes 4 4. The height of member 7 above the ground is xed by set screw 9. Since the distance between axes 8 8 is equal to that between the axes 4 4, the arms 3 3 and the member 6 form the familiar four-bar linkage, by means of which each point in member 6 is caused to move in an arc whose radius is equal to the length of the arms 3 3, and the plane through the axes 8 8 will always be horizontal.
The pivot axis 10, indicated on Fig. 1 by a dot and dash line, passes horizontally through the upper end of member '7 and terminates in the club handle at a pivot point 11. A bent arm 12 is carried by a horizontal bearing 13 in the arm 7 and is free to rotate about the pivot axis 10 as a center.
The arm 12 is inclined and terminates in an ear 14, to which a clamp socket 15 is held at an adjustable angle by wing screw 16. The socket 15 is provided with a slotted tapered hole which 'receives the round tapered end and hat shank of a club clamp 17 which consists of two parts shaped to lit the club shaft, joined at the outer ends by a hinge 18 and clamped firmly around the club shaft 20 by a wing screw 19 (see Fig. 3).
Fastened to the rear end of arm 12 is an annular bracket 21, which by means of set screw 22, can be adjusted at any desired angle with respect to the arm 12. An arm 23, carrying a cam roller 25 at its lower end, is slidably mounted in bracket 21 so that its length can be adjusted by a set screw 24.
The roller 25 moves along the upper surface of a cam 26, shown here as an angle-section shaped part of the frame, but it may be adjustably mounted on the uprights 2 2 of the frame in such manner that either end may be raised or lowered. The motion of the arms 3 3 and members 6 toward the right are limited by an adjustable set screw 27 in a bracket 28. An arm 29 keyed to the arm 12 carries a weight 30, which is adjustably fastened to the arm 29 by a set screw 31, and counterbalances the weight of arm 12 together with its club clamp fittings. An extension arm 32 (see Fig. 2) is secured to one of the arms 3, and by means of a sliding weight 33, which is adjustably held to the arm 32 by a set screw 34, counterbalances the weight of all parts carried by the four-bar linkage. The bearing 13 in the arm 7 is movable with the arm 12 along a path 35 which is the periphery of a cylinder from the center of which extends a plane 36 parallel to the arm '7 and perpendicular to the direction line.
tacts the ball, moving in a Straight line in the desired direction throughout the duration of contact between the club and the ball and in order to insure this it is well to have the peint of Contact continue in this direction after the ball has left the club. Moreover in all swings the golf club is rotating about the pivot axis 10 just before contacting with the ball, and during such. contact the pivot axis 10 itself travels along the surface 35 of the cylinder. The only possible way, in view of all these requirements, for a point in the face of the golf club to move along the direction line is for it to start at a point where the pivot axis, in its travel along its cylindrical surface 35, has just passed through the plane 36 through the axis of this surface, which is perpendicular to the desired direction line. At this point the plane containing the club shaft 20 and the pivot axis 10, which plane is rotating downward to the left about the pivot axis, must not yet have reached the position where it will become perpendicular with the desired direction line. The golf club is shown at this point for the putting stroke in solid lines in Fig. 2. In special cases of other golf strokes where it is desirable to have the point of contact between ball and club head moving in a line not parallel to the ground, the reference planes mentioned above will not be perpendicular to the ground, but the principles of motion will be the same. The line of contact between ball and club head cannot continue straight beyond the point where the plane containing the club shaft and the pivot axis becomes perpendicular to the line of contact, which in the case of the putting stroke would mean perpendicular to the ground since the line of contact is parallel to the ground. This position is shown in dot and dash lines in Fig. 2, and obviously any further movement of the pivot axis in its cylindrical path of travel, or any further rotation of the plane containing the club shaft and pivot axis about the pivot axis, will lift the club head away from the ground.
Between the starting position, which can be adjusted to any desired point by wing screw 27, and the second position, shown in Fig. 2, it is necessary that every increment of rotation of the pivot axis about the axis of the cylindrical surface in which it moves, be accompanied by an increment of rotation of the club head about the pivot axis, of such amount that the component of motion of the pivot axis upward away from the desired line of contact, is exactly balanced by the component of motion of the club head downward toward the desired line of motion. This coordination of the two rotations is accomplished in this device by the cam 26, which is so shaped that through roller 25 and arm 23 it limits the rotation of arm 12 and thus limits the rotation of the golf club about the pivot axis in the required manner. This motion could be exactly determined, instead of merely limited, by adding a surface to cam 26 parallel to the surface shown which would act on the top surface of roller 25. This however is unnecessary in the putting stroke since the power is applied to this part of the stroke by the hands of the player in such manner that the forces present will tend to keep the roller in contact with the cam.
The working portion of the cam lies, as shown in Fig. 2, between the plane 36 which is perpendicular to the direction line through the axis of the cylindrical surface in which the pivot axis moves, and the position of the plane through the golf club and pivot axis shown in the dotted lines Cil and iS approximately a straight line. The por- 75 lio message -3 utiono'ithe camto the"1ightof `the"iirst'ne'ntioried ...plane 'is "an are `with 'radius A.equa-1 to, "er greater Fthan, Ithe distance from Vtli'e `pivot axis" to the intersection df 'the cam' by this plane, and jserve's "merely t'o'guideth'e roller onto`th`e workingpor- 'tion'ion 'the"`down-swing. '.Theportion of thecam tothe left 'of 'the se'cond' position'isjcurveddown- .ward and is not incontact with'therllerafter v`the club VApasses beyond fthe second position.
'In operating the illustrated 'devicefthe player stands'in'iront of it 'and Agrasp's th'e upper part 'of the golf club "with his hands. By changing 'the length of the .arms ".3 'withthe 'set screws 5, the ^pivotlpointlll, as the playerswin'gs his arms to 'theleft and back, i.,e."the point where he would naturally ,piv'othis'wrists, follows "anarc oftravel best suited to his length .of arms, breadth 'of shoulders, etc. Then,`by raising o r'loweringlthe member 7 on the member T6 vwiththe 'set screw', and by raising 'or'lowering'the clamp 17 along the club shaft with the setserew 19, `the horizontal pivotaxis 10 isset at .a height above the ground most comfortable 'forhis length of legs, method of standing, etc., so it will pass through his natural pivoting point 11.
The base of the machine is set parallel to the line in the direction of which it is desired to have the ball move, the arm 12 is rotated to the right and the clamp 17 is adjusted along the club shaft until the face of the club is vertical and the bottom edge just clears the ground.
In this position, which is the starting position, the bracket 21 is adjusted on the arm 12 by the set screw 22, and the arm 23 is adjusted in the bracket 21 by the set screw 24, until the roller 25 just touches the cam 26 at the right hand edge of its straight portion, i. e. at the plane 36.
1n making the putting stroke, the ball is placed to the left of the club head in the starting posi- "tion, and the backswing is started by a rotation of the players wrists to the right about the pivot axis. The players arms do not move on the backswing and hence the pivot axis is prevented from any motion to the right by the wing screw The amount of the backswing depends upon how far the ball is to go along its direction line.
The forward swing up to the starting position is merely a reverse of the backswing, the player rotating his wrists to the left about the pivot axis until the club comes back to the starting position. At this point any further independent rotation of the wrists about the pivot axis is prevented by the cam 26 and roller 25 which force the arms of the player to carry the pivot axis to the left in its arc of travel while the rotation of the wrists continues, in such relative amounts that the head of the club follows along the ground in a straight line over the entire distance between the starting position and the second position striking the ball.
The ball has left the club head before reaching the second position, and what happens from there on has no eiect on the flight of the ball. The device is so arranged that after passing the second position the rotations of the arms and wrists are free to continue independent of each other until the momentum of each drifts to a natural stop.
The player may adjust the Wing screw 27 to diierent starting positions for putting various distances and determine the kind of stroke best suited to his individuality.
It is evident that the clamp 17 may be adjusted so that the face of the club will meet the ball at any desired angles both vertical and hori- L'Zorit`al,:"ani""that 'the 'jcoristructional varrangement 'ftheiaxe's willalways `cause'the 'face of the club -t'o "return to' 'theball y`from the back'swing at l these .predterminedanigles. It'isvalso evident that the screwil' 'determinesthe rotation of the clubs'haft about"`the club-shaft axis, which in the case illustrated does not change throughoutthe swing.
V"The round tapered portion vand 'flat shank of clamp 17,-.perni'it 'theplayer to lift the club, with 'the 'clamp 'still tight onit, outof clamp socket `15,fi`f he desires vto fuse"the club to move 'the Aball ba'ck 'to starting `position after 'making a shot, and quickly and leasily return VVit without losing the .adjustment of the clamp on the shaft or of the club-shaft angle by screw .16.
'Thus it can vbe seen, 'from the drawings and ythis specification, that `Ihave 'produced a device, "for use with golf clubs of '-varyinglength and`vary- .ringfanglesbetween shaft and head, by players of varying physical proportions, `to control all 'the .movements of the club ,necessary'to golf swings of varying lengths, whereby the player may acquire muscular skill and develop muscle memory through constant repetition of the act of bringing the club head against the ball at any desired angles and moving in any desired direction.
Various changes in construction can be made without departing from the spirit of my invention.
1. A device of the class described comprising a support, a member mounted lfor movement in a predetermined path relative to said support, clamping means pivotally connected to said member, said clamping means being constructed and arranged to hold the shaft of a golf club in a manner to swing about a transverse axis adjacent to its handle portion, and means associated with said clamping means and member movable in a predetermined path for eiecting coordination between their respective movements whereby to constrain the travel of the head of said club to a predetermined path.
2. A device of the class described comprising a support, a four-bar linkage mounted on said support, clamping means pivotally connected to said four-bar linkage and constructed and arranged to hold the shaft of a golf club in a manner to swing about a transverse axis adjacent to its handle portion, and means constructed and arranged to effect coordination between the respective movements of said clamping means and four-bar linkage tolimit the travel of the head of said club to a predetermined path.
3. A device of the class described comprising a support, a four-bar linkage mounted on said support with its connecting rod in depending position, an upstanding member rigid with said connecting rod, clamping means pivotally connected to said upstanding member, said clamping means being constructed and arranged to hold the shaft of a golf club in a manner to swing about a transverse axis adjacent to its` handle portion, and means associated with said clamping means and upstanding member for effecting coordination between their respective movements whereby to constrain the travel of the head of said club to a predetermined path.
4. A device of the class described comprising a support, a member mounted for movement in a predetermined path relative to said support, a crank arm pivotally connected to said member, clamping means connected to said crank arm, said clamping means being constructed and arranged to hold the shaft of a golf club in position to swing about a transverse axis adjacent to its handle portion, and means connected tol said crank arm to control rotation thereof and thus .effect coordination between the respective movements of said crank arm and member, whereby to restrain the travel of the head of said club to a predetermined path.
5. A device of the class described comprising a support, a rigid member mounted for movement in a predetermined path relative to said support, clamping means rotatably mounted on said member, said means being constructed and arranged to hold a golf club in position to swing about a transverse axis adjacent to its handle portion, and means constructed and arranged to control rotation of said clamping means at a predetermined portion of its path, thereby to effect a resultant movement of the head of said club along av predetermined path of travel.
6. A device of the class described comprising a support, a four-bar linkage mounted on said support, clamping means mounted on said four-bar linkage and rotatable relative thereto, said clamping means being constructed and arranged to hold a golf club in position to swing about a transportion of its path, thereby to eiect a resultant movement of the head of said club along a predetermined path of travel.
7. A device of the class described comprising a support, a four-bar linkage mounted on said support, a crank arm secured to said linkage and rotatable relative thereto, clamping means secured to said crank arm and constructed and arranged to hold a golf club in such position that the axis of rotation oi said arm intersects the longitudinal axis of said club adjacent to its han- DONALD W. PERIN.