US3845953A

US3845953A - Tennis serve training device

Info

Publication number: US3845953A
Application number: US00292907A
Authority: US
Inventors: F Malhas
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-09-28
Filing date: 1972-09-28
Publication date: 1974-11-05
Anticipated expiration: 1991-11-05

Abstract

A tennis serve training device is provided comprising a flexible sack or container for holding one or more tennis balls closed by an elongated longitudinal zipper. The container is swung by a tether attached at one end. The construction herein for closure of the container avoids the opening of such closure due to centrifugal forces in the course of using the device. A handle grip of relatively rigid material for the tether is provided for simulating the handle grip portion of a tennis racquet handle.

Description

United States Patent 11 1 Malhas Nov. 5, 1974 TENNIS SERVE TRAINING DEVICE [76] Inventor: Farouk S. Malhas, 3520 West Pl.

N.W., Washington, DC. 20007 [22] Filed: Sept. 28, 1972 [21] Appl. No.: 292,907

[52] US. Cl 273/29 A [51 Int. Cl A63b 69/38 [58] Field of Search..,. 273/29 R, 26 E, 95 A, 29 A,

[56] References Cited UNITED STATES PATENTS 2,197,977 4/1940 Haplin 273/29 R 2,311,160 2/1943 Dobbelaar 150/11 2,631,629 3/1953 Lee 150/1 2,717,015 9/1955 Berry 150/1 3,143,153 8/1964 Smith....

3,266,464 8/1966 Davis 248/361 A 3,653,660 4/1972 Malhas 273/29 A FOREIGN PATENTS OR APPLICATIONS 839,658 471939 France ..273/95A 49,406 10/1934 Denmark 273/97R Primary Examiner-Anton O. Oechsle Assistant Examiner-Theatrice Brown 5 7] ABSTRACT A tennis serve training device is provided comprising a flexible sack or container for holding one or more tennis balls closed by an elongated longitudinal zipper. The container is swung by a tether attached at one end. The construction herein for closure of the container avoids the opening of such closure due to centrifugal forces in the course of using the device. A handle grip of relatively rigid material for the tether is provided for simulating the handle grip portion of a tennis racquet handle.

9 Claims, 12 Drawing Figures PATENIEDNUV sum 3845;953

sum 1 or 2 I TENNIS SERVE TRAINING DEVICE The present invention is an outgrowth of further development of constructions with which I have experimented, for improving the device shown in my previously mentioned Pat. No. 3,653,660. The patent covers the method of using a swingable weight on the end of a flexible tether in such a manner that when the motion of a proper tennis serve is achieved the tether will remain substantially straight. In the previous construction the weight is in the form of a sack for holding several tennis balls, which provide mass, and wherein the sack is closed by a circumferential zipper. In my own use of this device with students I have found that a problem exists in the loosening of the zipper closure and general weakening of the container circumferentially. I attribute this structural weakening to the centrifugal force which must necessarily be present when the device is swung at high velocity since the tennis balls are impelled radially outwardly within the container and against the outer end. This produces a sufficient stress on the circumferentially disposed zipper as to weaken its holding power and in time rupture it.

As a result of the centrifugal force effect the device shown in my prior patent, while useable for the purpose of the method, was not longlived when put into constant daily use. The present invention solves the problem by using a longitudinally disposed closure in the form of a zipper so that no centrifugal forces are brought to bear across the transverse closing area and it has been found that such arrangement provides a more rugged, more reliable, and longer lasting device.

In addition to the above improvement, experimentation reveals that the overall use of the device is enhanced by the addition of a handle grip for the tether simulating a portion of a tennis racquet handle. Various handle grips are shown in the present application and are advantageously utilized as a means for selectively adjusting the length of the tether to simulate tennis racquet handles of different length.

A detailed description of the invention now follows in conjunction with the appended drawing in which:

FIG. I is an exterior view of an improved version of the device.

FIG. 2 is a view similar to FIG. I showing a handle grip on the tether.

FIG. 3 is a section through 3-3 of FIG. 2.

FIG. 4 is an exterior view of modified handle grip.

FIG. 5 is a section through 55 of FIG. 4.

FIG. 6 is an outer end view of a plurality of containers secured together.

FIG. 7 is a fragmentary side view particularly in section of the plural arrangement shown in FIG. 6.

FIG. 8 is a side view of another form of container.

FIG. 9 is an exploded view partially in section of the container of FIG. 8 and a handle grip.

FIG. 10 is a view in the direction l0l0 of FIG. 9.

FIG. 11 is a fragmentary perspective of another form of the invention utilizing a handle grip for one or more tethers. and.

FIG. I2 is a section through 12-12 of FIG. 11.

Referring to FIG. 1, the construction utilizes a cylindrical sack or container 10 of flexible material, such as vinyl, having an outer end 13 and an inner end 16, both ends preferably dome shaped as shown, and secured as by stitching or cementing at the respective welts 13A and 16A to the body of the container. It will be appreciated that the making of such a flexible container is well within the skill of the art and that details of construction and assembly need not be set forth herein. However, it should be noted that the entire container could be integrally molded of soft polyethelene or other materials by conventionally known method of manufacture for containers.

Regardless of the mode of manufacture of the container it is provided with a longitudinal slit 20 to the sides of which are fastened a zipper device 24. Accordingly, it will be understood that the container may be opened or closed by means of the zipper for insertion or removal of one or more tennis balls 27. I have found for practical purposes that three tennis balls in a vinyl container is entirely suitable for purposes of practicing the method of the invention. A tether for swinging the container may be of any suitable rope or plastic material having a wrist loop 33 to encircle the users wrist, the loop being formed by a clinched ring 35 in a well known manner. In this instance, the tether extends upwardly through a grommet 38 at the inner end of the container, into the container and then outwardly of the container through another grommet 40 to be folded back against itself at its free end and secured by a tightly fitting O-ring 43 of rubber or other suitable material. It will thus be apparent that the length of the tether is adjustable dependent upon how much of the free end 45 is pulled through the grommets and O-ring. The frictional effect of the tether passing through the grommets and the O-ring is thought to be sufficient to hold the tether to any adjusted length for simulating a selected length of tennis racquet handle. However, it will be obvious that the free end 45 may be tied around the tether if necessary.

Referring now to FIGS. 2 and 3 the construction as to the container 10 is identical to that described above and need not be repeated. In this instance the tether 48 is secured to the inner end of the container by passing through a grommet 50 and being knotted at the end 52 or otherwise provided with a clinched ring which cannot pass through the grommet 50.

The tether 48 passes through a central aperture 55 in a handle grip 58 axially bored and then bends upwardly or longitudinally along the handle to fit into a longitudinal groove 60 of the handle grip. A groove 63 is provided substantially circumferentially around the handle grip merging onto groove 60 and a rubber O-ring 65 in groove 63 clinches the rising end of the tether in the groove 63. To increase the frictional grip of the groove 60 and the O-ring it may be provided with a relatively straight side as indicated in FIG. 3. The free end of the tether may be secured to the tether by an O-ring 66. It will be apparent from the foregoing that the tether length may be adjusted as desired by removing the 0- rings and pulling the tether in either direction through the handle grip, and replacing the O-rings.

Referring now to FIGS. 4 and 5, a handle grip is shown for holding a plurality of three tethers such as 48, shown in cross section in FIG. 5, which tethers pass through an axial bore 68 in a handle grip 69, and then will be understood to bend or fold around the outer end of the handle (as illustrated for the tether in FIG. 2) so as to be disposed in respective longitudinal grooves 70 arrayed equiangularly on the exterior of the handle grip. The tethers are secured in respective longitudinal grooves by rubber O-rings 73 in respective circumferential grooves such as 75 in a manner similar to the gripping effect of O-ring 65 of FlG. 2. Accordingly, the handle grip shown in FIGS. 4 and 5 can be used for 1, 2, or 3 containers to be swung simultaneously. Preferably all of the tethers would be adjusted to the same length in the manner described for the handle of FlG. 2.

Referring now to FlGS. 6 and 7, another mode of securing a plurality of containers is illustrated wherein the outer ends of the containers 80 are provided with central grommets 82 and an elastic ring 85 is provided with hooks 88 suitably curved to fit into respective grommets 82 thereby hooking all three containers together. The tethers (not shown) for such containers may be as shown in FIG. 1 with wrist loops or they may be gathered in a handle grip shown in FIGS. 4 and 5.

Referring now to F165. 8 through 10 the container 92 in this instance is closed at its outer end 92 and open at its inner end 95. The container is of sufficiently soft material, for example, cloth or suitable plastic, and provided with parallel pairs of grommets 98 spaced along the length of the container. The tether 102 can be passed through any pair of opposed grommets to bring together the'open end of the container trapping tennis balls therein whereby the container may be, in effect, lengthened or shortened dependent upon the number of tennis balls desired to be used for purposes of the invention.

In this instance the tether is doubled and threaded through slanting

slots

105 and 106 of a handle grip 109 wherein the angularity of the slots frictionally grips the doubled tether to hold the tether length to any selected simulated racquet handle length. If need be, the number of angular slots may be increased to positively insure frictional gripping. The two sides of the tether are held together by a rubber O-ring 112 adjacent the inner end of the container in order to insure maintenance of closure.

Attention is now invited to FIGS. 11 and 12 showing yet another form of handle grip for holding one or more tethers. in this instance a simple cylinder 115, which may be a plastic tube, encompasses three tethers 30, the loops 33 of which come out below the handle grip for encircling the wrists of the user. The hand of the user would grasp the cylindrical handle grip in simulation of grasping a tennis racket handle. The tethers are simply passed through the tube, loop ends first.

in all of the foregoing modifications, it will be understood that a selection of materials is available for the sacks as well as the handles and tethers. For example, suitable soft plastics or even woven materials can be used for sacks and tethers while the handles may be of wood, plastic or-light weight metal such as aluminum and of any desired contour simulating the shape of a tennis racquet handle.

What is claimed is:

1. A tennis serve training device comprising an elongated closed end hollow container transversely dimensioned for holding only a single row of alined tennis balls to effect a predetermined weight, a single tether secured to an end of said container extending axially thereof for swinging said weighted container in an arc to simulate the movement of a tennis racquet in a serving movement wherein centrifugal force effects a longitudinal tension in said container; said container having a longitudinal side opening for inserting and removing tennis balls and a closure means for said opening extending longitudinally therealong to retain tennis balls in said container and being thus disposed to preclude tension due to centrifugal force from acting in a direction tending to open said closure means.

2. A device as set forth in claim 1, said container being of flexible material and said closure means being a zipper.

3. A device as set forth in claim 1, including at least one additional identical device, and a grip handle having passage means for receiving and securing said tethers and simulating a portion of a tennis racquet handle.

4. A device as set forth in claim 3, said handle grip having means to secure said tethers at a selected distance from said containers to effect a simulated tennis racquet handle of selected length.

5. A tennis serve training device, as set forth in claim 1, and a handle grip to which said tether is secured and simulating the handle grip portion of a tennis racquet.

6. A device as set forth in claim 5, and adjusting means to secure said tether at predetermined distances from said container to simulate tennis racquet handles of selective length.

7. A device as set forth in claim 5, said handle grip being tubular, said tether passing therethrough at one end and having a wrist loop extending therefrom at the other end.

8. A device as set forth in claim 5, and adjusting means to secure said tether at predetermined distances from said container to simulate tennis racquet handles of selective length, said handle grip being tubular, said tether passing therethrough at one end and having a wrist loop extending therefrom at the other end.

9. A device as set forth in claim 8, including at least one additional identical device having the tether thereof passing through said handle grip and having a wrist loop adjacent said first mentioned wrist loop.