US 1457710 A
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v J. M. MwDoNALD ARM LOCK FOR GOLF PLAYERS Filed March 1o, '1922 2 Sheets-Sheet l `June5, 1923. Y 1,457,710
J. M. MaCDONALD ARM LOCK FOR GOLF PLAYERS Filed March 10, 1922 2 Sheets-Sheet 2 A vwantoz,
Patented June 5, 1923,
i Unirse! s.
.AMEs MAXWELL MACDONALD, 0E iiAsfi.1 ,oEANerE` NEW JERSEY. lf I AEM Look` EOE-Gom* PLAYERS.
Application med March 1o, i922.' serial No. `542,59a
Y v To all whom tima concern:
' Be it knownthat ,JAMES M. MACDONALD, a citizen of the United States of America, residing at East Orange, in the county of 5 Essex, and State of NewV Jersey, have invented certain new and useful Improvements in Arm Locks for Golf Players, of which the following is a full, clear, and eXactdescription. j
The-invention.` which forms the subject of this application for Letters Patent is an appliance designed as an aid, particularly for beginners, but also for eri-ing adepts, in the teaching of correct form in the game of golf. In this game oneof the mostessential pointsy in the art of addressing and ,striking the ball, particularly with the wooden clubs, is technically known as the follow through. That is to say, the stroke is not of the nature ofahammer blow or the swing of a baseball' bat,fbut in order that the club shall doits full work, it must, after impact of itsface with the ball, be carried lthrough `its full stroke, or otherwise.the 'pathof the ball will not be true nor its travel complete.
j This follow through is accomplished only when the arm in the course ofthe stroke is` straightened out and kept straight until the full stroke or swing is completed. If before or after-.impact the arm is bent the proper stroke is not accomplished and it is not only a matter of considerable. difficulty forv beginners tov learn and practice this, but even old and skilful players are very apt to fall into ,the fault of not following through tothe inevitable detriment of their game.
I have devised a mechanical attachment for the arm of la player which I term' an arm lock, and which is so constructed and 40 operated by the playerl in the movement of his arm asto lock the arm` in its extended or straightened position once it is brought to such position in the course of the stroke. The device comprises what may be termed a supporting saddle `attached `to the arm above and below the elbow, and a locking element which comes 'into play when the arm is'straightened and preventsthe bending of the arm until means are operated that unlock saidelement. The device thus not .V only serves to show the player when his accompanying drawings.r j
stroke is suchy astosecure" the prope r"fol V low through? butv induces'him to make such strokes. whether he intends'to 'orknot.`v My improved arml lockis .shoi'zvnjV in the Eig, i is a View in perspective ortica@- vice showing the manner in which it is' 3,13.-
tached to the arm of the player. j
Fig. 2 is ajlongitudinal section `of thej ydevice the parts in thev position occupied by them when the arm is Afully bent.
Fig. 3 is a horizontal section of thedevice l' on the lline 8 3 of Fig. 2,1 looking down ward, or in the direction ofthe arrow. Fig. 4 is a longitudinal section of thel 'de+y -vice showing the parts .in the position they occupy when the arin` is `straight and the locking device has .beenf rendered effective.` Fig. 5 is asimilar view showing the operation of the means for unlocking theksaid locking means. v
Fig; l6 is a section on-fthe line 6 6 4of Fig.2. I i .v
Fig. 7 yis a sectionfon ytheliiie 7--7'of The device kcomprises essentially two ele-` iirst named being adapted to beI strapped'to the arm just above, the Vother to the arm just 3 or 'similar` meansbeing employed for this vments or'plates l and 2,'hinged together, the
purpose. In applying the dev'ice the plate 2 is first strapped l,after it is adjusted in' position on the forearm with4 the elbow down andthe hinge- 4 contiguous to the elbow joint or knuckle.' The plate l' is then strapped to the biceps and when the attachmentis secure, the `device will always lock yas' soon as the arm` is straightened and prevent it Vbeing bent until it is unlocked. j
To accomplish this result a tubular member'5` is hinged to the. member-2 and a rod or bar Gis 'hinged or pivotedto 'the member l and works in the tube` When the armis straigfhtened the rod is vdrawn out nearly to the end of the tubey 5, or into the A positiony shown in Fig. y. u
The tube 5, mai ly for convenience of manufacture, containsfa'smaller tube 7, and
is made in two parts, one part 8 being adaptedV to yslide overthe, inner p'artf7`but keyed y 80 below the elbow, any suitable rform of 'straps of the thereto by a pin or screw 9, that enters a longitudinal slot 10 in the tube 7. The said movable part 8 also carries a relatively thin plate 1l which slides in a slot 12 in the under side of the tube 7 an'd extends to or slightly beyond a shoulder 13 formed by the end of tube 7 and a wider groove extending only partially through the wall of the part 8.
Normally, therefore, the rod 6, under the movements of the arm slidesback and forth in the inner part or tube 7, but when the arm is straightened the pivoted rod drops and engages the shoulder 13, which locks it and prevents its return into thel tube 7 and hence prevents the arm from being bent.
I To unlock the device the part y8 is grasped between the fingers and thumb and moved awayy from the stationary part 5 with the result that, the ybevelled end of the plate 11 raises'h the rod into' line with the bore Y art 7 and permits the arm to be bent, yIn Fig. 5' the parts are shown in the position they occupy after the rod has been raised by thepart 8 and passed back a certain distance in the part 7. After the device has been unlocked in this way the part 8 is pushed back to the position shown in Fig. 4', and it is held in this position by meansV of a spring 14. n
For steadying the device and adding greater strength it is desirable to' secure to one member, as for example 2, a socket tube 15, and to pivot to the other member a bar or rod 16 containing a slot 17 through which passes a pin 18 secured to the tube or socket 15.V
Perhaps they majority of players do not hold the arms straightened to full length in addressing the ball. In such cases they would not be locked by this device, until by the force of the stroke or swing the arm is momentarily forced straight. In such cases itvwould not be locked until this happened, which would give the player the benefit of the full follow. i
In case, however, that the player straight ens his arms inV addressing the ball, then themovable part 8 should be `drawn back, which will prevent the device from locking. But by centrifugal force the part 8 during the stroke would be thrown back to normal position, which willvallow the device to lock the moment the arm becomes straight. In addition to the described functionlof a locking device a timing means for the backward stroke is employed. This con'- sists in a metal ball 19 contained in the otherwise empty end of the inner tube 7 and restrained in its movements, due to gravity by two stops 20. Should the club bel swung back quickly, the ballv will be held against its forward stop and give no evidence of displacement, but a slow backward stroke', coming to a full momentary stop, as is taught by professionals, will permit the ball to fall upon the upper or rear stop, the clicking due to the impact being distinctly audible.
Se fai' as my information goes, this device is new of` its kind and is not therefore limited to the specific construction shown and described. For example, other means than those shown may be employed to lock the device when the arm is fully extended, and other means may be employed for unlocking the same. The device may be worn over or un'dera sweater 0r other article'of clothing. y
A Having now described my invention, what I claim is l. An arm lock forl golf players, comprising in combination two parts or elements adapted for attachment to the biceps and forearm respectively, and hinged together, and locking means' for holding the saine in fixed relative position operating upon their change of relative position diie to straightening of the arm to full length.
2. An arm lock for golf players, com# prising in vcombination two platesrwith da' hinged connection between them, and adapted to be secured to the biceps and the fore arm respectively. a part pivotally connected prising in combination two platesfwithv `a l hinged connection between them and adaptd ed to be secured to the biceps and forearm respectively, a tubular member carried by one plate, a pivoted ,rodv attached to the other and movable in said tube, and a fixed stop in the tubular member with which said rod engages to .lock the two plates in fixed relation whenA by the straightening` out of the arm they have undergone a predetermined relative movement.
4' An Mm 100k for golf playera coinf i prising in combination two plates hinged together and adapted for attachment to the biceps andv the forearm respectively, a tube carried by one plate, a rod pivoted to the other and sliding in said tube, a notch being provided in the bore of one tube with which the end of said rod comes in engag'el ment when by the straightening of the arm the two plates have undergone a Apredetermined relative movement. r
5. An arm lock for golf players, coin-y prising in combination two plates hii'i'ged together and adapted for attachment to`- the biceps and the forearmre'spectively, a tube carried by one plate, a rod pivoted to the other and sliding in said tube, av fixed stop 1,457,710 l k3 t.
inthe tube with which the end of the rod movableby gravity between lxedstops .in engages after a predetermined relative` said tube, and adapted. to givev audible eviV` movement of the two plates, and a movable `plate carried in or by said tube for lifting In testimony whereof vI hereto afx my 5 said rod out of such engagement.'-v signature.v Y vv f 6.9111 arm lock for golfl players compaging a tube in combination with a bau JAMES MAXWELL MACDONALD l dence of its impact with one of said stops. 10