US 2019224 A
Description (OCR text may contain errors)
Oct. 29, 1935. E. HESS SWIMMING PRACTICE APPARATUS 3 Sheets-Sheet 1 Filed Feb. 10, 1835 lnveniozw: 27 ErFzy-wd Hess, 6 ra nn-w Oct. 29, 1935. E. HESS SWIMMING PRACTICE APPARATUS Filed Feb. 10, 1933 3 Sheets-Sheet 2 Ina/anion. Erhc; z dfss, 7 diffs Oct. 29, 1935. E. HESS 2,019,224.
SWIMMING PRACT I CE APPARATUS Filed Feb. 10, 1933 3 Sheets-Sheet 3 fave-77,2?) r.- .E'rhard Hes-s Patented Oct. 29, 1935 UNITED STTS Claims.
This invention relates to machines for instruction in the practice of swimming, being intended more particularly, though not exclusively, for instruction in what is known as the crawl (or 51 "sometimes the American crawl) stroke in which the hands of the swimmer pass each through a substantially vertical orbit at the side of the body. In this movement the hands are extended forward in alternation, sweeping downwardly and back- 'Iwardly, the feet being kicked up or down in alternation and coordinately with the movement of the hands and arms.
In this machine provision is preferably made so that not only are the movements of the hands and feet guided and coordinated to conform to the correct execution of the stroke so that the swimmer learns by practice instinctively to perform such movements, but the mechanism is operated by the muscular power of the swimmer himself so as to develop and train the muscles which primarily come into play in executing this stroke;
The invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.
In the drawings:-
Fig. 1 is a side elevation of a machine embody- 20 ing one form of the invention;
Fig. 2 is a plan view of the machine shown in Fig. 1;
Fig. 3 is a plan of the driving connections between one of the hand straps and the driven sprocket" on a somewhat enlarged scale;
Fig. 4 is a cross-sectional elevation on the line 4-4 in Fig. 3;
Fig. 5 is a rear elevation of the machine shown in Figs. 1 and 2;
Fig. 6 is a side elevation of one form of load imposing device associated with the intermediate driven sprocket wheel; and
Fig. 7 is a partial end elevation of the parts shown in Fig. 6 on an enlarged scale and looking in the direction of the arrow in Fig. 6.
Referring to the drawings and to the embodiment of the invention there shown for the purpose of illustration, the apparatus is mounted upon a light but strong portable frame, preferably consisting of angle irons, and comprising primarily a. pair of spaced, upright members I! and I3 connected at their bottom ends by the member l5 and somewhat below their upper ends by the horizontal member I! forming one side 55.; (herein the left-hand side) of the frame. Associated with this are corresponding upright members I9 and 2!, with a similar lower connecting member and an upper connecting member 23, forming the opposite or right-hand side of the fram'e, leaving an intervening space in which 5 the subject, hereinafter referred to as the swimmer, is positioned.
The bottom connecting members are prolonged at their rear to provide, in conjunction with uprights 25 and Zl and cross-connecting members 10 29, 3! and 33, a smaller extension of the frame for supporting certain of the operating parts at the rear thereof. At the front the opposite sides of the frame are connected at the bottom by the cross-connecting member 35. 35
Fixedly secured to upright frame members 36 and between the two sides of the frame is a body rest or table 31 adapted to support the body of the swimmer and on which he lies prone and face downward, his legs extending rearwardly over 20 the two separate leg boards 39, the latter being hinged to the rear edge of the body rest or table 3! so as to be freely movable up and down with relation thereto and provided each at its rear end with a foot rest or holder M adapted to re- 25- ceive the toes of the swimmer and hold the feet and legs in fixed position on the leg' boards, so that movements imparted to the latter are adapted to direct the movements of the swimmers legs. extending through the slot 33 in the leg board so as to be adjustable for persons of different leg lengths.
Each leg board has journaled on its under side a cam roll 45 riding on its own cam M, the two cams being secured to a common cam shaft 59 journaled in bearings supported by the rearwardly extending and upwardly inclined frame ment bers 5|. The two cams M are set apart and are preferably designed to provide a uniform 4O rising and falling movement for the leg boards. To guide the swimmers hands and arms in the proper orbit there is provided at each side of the frame and rigidly secured th reto a closed, guiding trackway 53 of the shape best shown in Fig. 1, 45 where it will be seen that it comprises an upper, substantially horizontal portion merging into a lower portion which conforms to the arc of a circle. The trackways thus present guides Which define in each case a non-circular orbit lying in a substantially vertical plane at each side of the swimmer. This trackway herein consists of a continuous, relatively thin strip of metal but of generally rectangular cross-section, there being 55 Each foot holder M is fastened by a bolt 30 two similar guiding trackways, one for the right arm and another for the left arm.
Mounted to run easily and with slight friction on the trackway is a small, light guide frame comprising the grooved rollers 55, 55 (Fig. 3) engaging the opposite convex edges of the tracking strip, the rollers being journaled in the plate 5'! which holds them in fixed relation to the trackway but is pivotally secured to the sliding connecting rod 59 through which the machine is driven by the movement of the swimmers arms. The arm propelling mechanism for the two opposite sides of the machine is substantially the same and one only need be described. 7
Means are provided to permit the swimmer to grasp and simultaneously move the two connecting rods 59, and for this purpose there is attached to each rod a holding strap 6| adapted to encircle and be fastened about the palm of the hand, allowing the hands to remain open in executing the arm stroke. Each strap has a swivel attachment to its connecting rod by means of a bolt secured in a threaded hole in the connecting rod, a spaced series of holes being provided so that the position of the strap may be adjusted to suit the reach of the individual.
The forward and downward movement of the swimmers hand acts through the connecting rod 59 to rotate a shaft 63 journaled in bearings on theframe member I! (the right-hand shaft being journaled on the frame member 23), the axis of this shaft being aligned in close approximation to the shoulder of the swimmer about which the sweep or full movement of the arm takes place and coinciding substantially with the center of the arc to which the lower run of the guiding trackway conforms.
On the shaft 63 is mounted a sprocket wheel 65 driven through a compensating mechanism, later described, and acting in turn to impart the necessary movement to the foot board cam M. Since the radial distance between the shaft 63 and the trackway 53 varies at different points in the orbital movement of the hand, the connecting rod 59 is mounted for sliding movement in the two opposite arms of the crank member 61 (Fig. 3), which latter is fixedly secured to the shaft 63. The result is that as the hand sweeps forward along the upper horizontal run of the trackway toward the downwardly extending part thereof, the connecting rod slides outwardly in its crank arm increasing the eifective radius or leverage, and as it moves back on the horizontal run of the trackway it slides into the crank arm decreasing its effective radius or leverage.
The two opposite sprocket wheels 65 are connected each by a sprocket chain to drive sprocket wheels 68 fixed on opposite ends of the intermediate shaft 69, the latter journaled in bearings secured on the upright frame members 25 and 21, the shaft 69 in turn having fixedly secured to it the larger intermediate sprocket wheel H connected by a sprocket chain to drive the smaller, rear sprocket wheel 13 secured to the foot-board cam shaft 49 for turning the foot-rest cams 41.
The two roller guide frames occupy positions at all times 180 apart with relation to the. axis of the shaft 63. The sprocket wheels 65 and 68 are of the same size so that the shaft 69 and sprocket wheel ll make one complete revolution for each complete cycle of arm movement. The intermediate sprocket wheel H is herein three times the diameter of the sprocket wheel 13, so that for each complete cycle of arm movement the cams 41 each complete three revolutions, enforcing three beats or complete reciprocations of each leg board or an aggregate of six beats for the two legs of the swimmer, the movements of the two legs being opposite to each other and in alternation. This provides the leg movement ordinarily 5 used in the American crawl stroke, but by replacing the intermediate sprocket wheel H or the cam shaft sprocket wheel 13 with wheels of different sizes, the number of beats for each cycle of arm movement may be varied as desired 10 During the forward movement of one guiding frame, for example, the left-hand frame, on the horizontal run of trackway, and until it reaches the arc-shaped portion thereof, the other or righthand guiding frame is traveling on the arc-shaped 15 portion and at a relatively greater linear velocity than the first or left-hand frame. Accordingly, the movement of the right-hand shaft 63 driven thereby tends to accelerate with relation to the movement of the companion or left-hand driving 10 shaft. To prevent the acceleration in the movement of one shaft from interfering with the simultaneous retardation of the movement of the other shaft, a lost motion orcompensating driving connection (Figs. 3 and 4) is provided between each It" shaft and its driven sprocket wheel 65, both of which, it will be recalled, are chain-geared to the same intermediate driving shaft 69.
For this purpose the sprocket wheel 65 is loose on the shaft 63 but is provided with a pin 15 posltioned eccentrically andextending laterally from the inside face of its hub. The pin 15 projects into a recess 11 formed in the opposing face ofa collar 19 fixedly secured to the shaft 63. When the shaft 63 is rotated the collar and pin serve as the driving connection for the sprocket wheel. The recess Tl, however, permits the pin to move therein and the shaft 63 on one side of the ma chine to lag behind its sprocket wheel when the shaft on the opposite side is accelerated by the 0 travel of its guiding frame over the arc-shaped. portion of the trackway.
This not only relieves any binding action in the gearing connection between the two shafts 63, but automatically transfers the load of driving 45 the apparatus to the arm which is executing the downward, backward and upward sweep, present ing an increased resistance thereto, while relieving from any substantial load the other arm which is being extended forwardly. This simu- 50 lates the conditions in actual swimming, where the downward and backward sweep of the arm is the movement through which propulsive power is imparted to the stroke against the resistance of the water, while the subsequent forward move- 55 ment of the arm is merely intended to reposition the hand for repeating the power stroke.
If desired, means may be provided additionally to impose an artificial load on the arm movement when executing the first part of the downward and backward sweep where somewhat more resistance is encountered in performing the. stroke in the water than in the finishing part of the sweep. As illustrative of such means. (see Figs. 6 and 7) there is shown as secured to one: OS face of the intermediate sprocket wheel H two oppositely positioned and spaced segmental brake: shoes 8|, in the path of the periphery of which there lies a curved spring 83 adapted to. exert a frictional drag on the sprocket wheel when the 7 shoe passes thereover. The free end of the spring rests slidably in a yoke 85 supported between the frame members 5|. The result is that as one arm of the swimmer sweeps down over the first part of the arc-shaped portion of the trackway, one 7 of the shoes engages with and passes over the spring, adding somewhat to the resistance encountered by the movement of the arm, this additional resistance being relieved during the time the arm performs its upward sweeping movement, but a similar and similarly timed resistance being imposed on the other arm when the other segmental shoe passes over the spring 83. It will be observed that the radial distance from the center of the sprocket Wheel to the periphery of each brake shoe is greater near the middle of the shoe and decreases somewhat toward each end, the result being that the effort required to be exerted by the swimmer in the execution of the power stroke first increases and then decreases in close simulation to the effort called for in executing the stroke in the water.
The operation of the apparatus will be readily understood from the foregoing. To operate the machine, the swimmer lies face downward on the table, placing each foot in the respective foot rest and placing each hand in the hand strap provided. Adjustment may be made in each case to accommodate the stature of the swimmer. By pushing the roller guiding frames forward and around the trackway the driving mechanism is set into operation, causing the legs to move up and down in the desired ratio and in coordination with the movement of the arms.
This not only provides a beneficial exercise and a means for teaching the novice the correct stroke, with perfect coordination of the movement of the legs and arms, but also a means for perfecting the stroke and keeping in practice where swimming facilities are not available, and at the same time develops the muscular power required for performing the stroke.
While I have herein disclosed and described for the purpose of illustration one specific embodiment of the invention, it is to be understood that this is illustrative only and that extensive deviations and changes may be made in the apparatus herein illustrated, all within the scope of the claims and without departing from the spirit of the invention.
1. In an apparatus for instructing in the crawl stroke of swimming, the combination with means for supporting the body of the swimmer in prone position, of means for directing the movement of the two hands alternately first forward and then downward and backward in a substantially vertical plane, and mechanism driven by the movement of said hands, said mechanism having means to present a greater resistance to the downward movement of each hand than to the forward movement thereof.
2. In an apparatus for swimming instruction, the combination with means for supporting the body of the swimmer in prone position, connections for attaching to the apparatus the legs and arms of the swimmer, mechanism for guiding and coordinating the movements of the arms and legs, means for driving said mechanism through the muscular power of the swimmer, and means for imposing a different load on the swimmer for different parts of the swimming stroke.
3. In an apparatus for swimming instruction, the combination with means for supporting the body of the swimmer in prone position, of a noncircular guiding trackway defining an orbit for each hand of the swimmer, means adapted to be secured to each hand of the swimmer for guiding said hand along said trackway, a driving member connected to be rotated by the movement of each hand through said orbit, a driven member for each driving member, said driven member being interconnected to maintain the hands in fixed relationship one to the other, and a lost motion connection between each driving and driven member.
4. In an appartus for swimming instruction, the combination with means for supporting the body in prone position, of a non-circular guide for directing the movements of each hand of the swimmer in an orbital path in alternation first forwardly and then downwardly and backwardly, a driving member connected to be driven by the movement of each hand at a varying rate of speed in different parts of the orbital path, a driven member, and a lost motion connection between the driving and driven member.
5. In an apparatus for swimming instruction, the combination with means for supporting the body of the swimmer in prone position, of a guide for each hand defining a non-circular orbit, mechanism driven by the joint movement of said hands, and a lost motion driving connection between each hand and the said driving mechanism.