US 3531115 A
Description (OCR text may contain errors)
Sept- 1970 R. A. ALEXANDER 3,531,115
' BATTING PRACTICE DEVICE Filed Dec. 15. 1966 44 1O INVENTOR. l 6 ROBERT A. ALEXANDER iq- 5 BY WW A TTORNEY United States Patent O US. Cl. 273-26 2 Claims ABSTRACT OF THE DISCLOSURE 'A ball is secured to the end of a line and used for batting practice by swinging the ball in a circular path or by pitching the ball while an end of the line is anchored to the ground. The ball and line have different elastic characteristics and are connected in a manner to prevent differential elongation for unequal stress.
BACKGROUND OF THE INVENTION This invention pertains to apparatus for games, and more particularly to devices for perfecting the playing of the game of baseball.
Baseball is considered the national pastime of the United States and boys learn the game at an early age to compete in the Little League and Pony Leagues. It is difiicult for a boy to get practice batting because of the lack of playground area, insufiicient players to field hit balls, or not enough time when the ratio of batting to fielding is one to ten. To overcome such difiiculties, batting practice devices have been developed which utilize simulated baseballs fixed to the end of a line and swung in a circular path or pitched from an anchor in the ground. A batter and a pitcher can practice with such a device in a limited area and by taking turns, each will gain a great amount of batting practice in a short time. One of the difficulties encountered with these devices is the manner in which the ball is secured to the line. When the ball is swung in a circular path, centrifugal force tends to compress the ball and elongate the line. This tendency for a differential movement between ball and line causes wear therebetween. Also, there is a need for resiliency at the connection when the ball receives the direct impact of the bat and when the line limits the path of travel of the ball. Previous patents show the passing of a cord diametrically through a ball and fastening the cord in a manner so that it can not be drawn back. The cord is in contact with the ball around the sides of the hole and since the cord elongates under tension, there is a tendency for wear about the cord. One method used to eliminate this problem was to pass an elastic cord through a sleeve within the ball, the sleeve being spaced from the cord. This spacing eliminates the tendency for friction wear but the sleeve inhibits the resiliency of the ball.
SUMMARY OF THE. INVENTION A batting practice device in the form of a ball secured to a line with that portion of line passing through the ball prestressed in tension. One form of the invention provides for the connection of a resilient ball to a line which is less resilient. A second form of the invention provides for connecting an elastic line to a ball having less resiliency. Such connections provide resiliency to withstand batting impact and eliminate wear due to differential elongation.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view with a portion in perspective illustrating a batting practice device embodying the present invention.
FIG. 2 is a diagrammatic view illustrating one form of application of the batting practice device.
Patented Sept. 29, 1970 FIG. 3 is a diagrammatic view illustrating a second form of application of the batting practice device.
FIG. 4 is a sectional view through the ball shown in FIG. 1.
FIG. 5 is a sectional view of a ball illustrating a modified form of the invention.
FIG. 6 is a transverse section taken on the line 6-6 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS A batting practice device 10, as shown in FIG. 1, includes a ball 12 secured to a line 14. The ball simulates a baseball or softball and the line is made of light clothes line cord. The end of the line opposite from the ball is connected to a swivel 16 that is fastened to handle 18 by pivot bolt 20. As an optional accessory, a ground anchor 22 can be attached to the handle. The anchor has a stud 24 which fits telescopically into a longitudinal bore, not shown, in the lower portion or the handle. A pin 26 fits through a transverse hole 28 in the handle and a similar hole 30 in the stud portion to lock the anchor to the handle. The anchor includes spikes 32, 34 and 36 for penetrating the ground at spaced positions to hold the practice device in place.
FIG. 4 illustrates the manner in which ball 12 is secured to line 14. This is a resilient ball made of fairly dense sponge rubber and has a diametrical hole 40 positioned therein. The line is threaded through the hole and a first knot 42 is tied in the end of the line. A first stress distributing pad 44 in the form of a neoprene or rubber washer is interposed between the first knot and the ball. A first portion 46 of the line extends through the hole in the ball to a second stress distributing pad 48, interposed between the ball and a second knot 50. A second portion 52 of the line extends outwardly from the second knot to connect with the swivel .16. The resilient ball is compressed between the stress distributing pads since the length L of the first portion of line is less than the diameter D of the ball. The pressure which the compressed ball exerts against the stress distributing pads is transmitted against the knots placing the first portion of the line in tension. The amount of pre-tension stress varies as the ball is compressed and with the resiliency of the ball so the length L should be set to equal the dimension of the ball compressed by centrifugal force.
The batting practice device 10 can be used in two ways for developing the eye of a batter. The first, illustrated in FIG. 2, shows a pitcher 54 holding the handle 18 in his hand and Swinging the ball 12 in a circular path as indicated by the line 56. A batter 58 stands along the circumference of the circular path and swings at the ball as it passes by. Using the batting practice device in this manner, a suitable length of line 14 is about fifteen feet so that the ball travels in a circle having a diameter of about thirty feet. A plurality of batters can stand at points spaced along the circumference of the circle and practice their batting. The pitcher can develop great speed by swinging the ball about his head without a great amount of effort or strain upon his arm. By moving his arm towards the batter, he can cause the ball to travel in the manner of an inside pitch, while drawing his arm towards his body causes the ball to move outside. By raising and lowering the handle or tilting the plane of rotation through which the line passes, the ball can be made to travel for simulating high or low pitches. Centrifugal force tends to push the ball outward against the first stress distributing pad 44, compressing the ball against the pad and putting tension in the line. Since the ball was compressed originally between the stress distributing pads and the first portion of the line was pretensioned therebetween, there is no differential movement due to the 3 centrifugal forces until they exceed the initial compression stress placed in the ball and the tension stress placed in the first portion 46 of the line. Thus, differential movement is reduced and friction Wear is eliminated within the hole 40 so that the life of the ball is prolonged.
A second way of using the batting practice device is shown in FIG. 3. The ground anchor 22, as shown in FIG. 1, is used to secure the handle 18 to the ground 59 midway between a pitcher 60 and a batter 62. The pitcher delivers his pitch to the batter in the regular manner and if the ball 12 passes the batter, it is stopped by the line 14. If the batter hits the ball, it will travel back towards the pitcher and again be stopped by the line. Using the batting practice device in this manner, a length of line of about thirty feet has been found to be desirable. Whenever the line stops the travel of the ball, the force is absorbed by the first stress distributing pad 44 putting the ball in compression and the first portion of the line in tension. The effect of the pre-tensioned stress in the first portion of the line is to balance out the shock stress and eliminate any movement of the ball upon the first portion of the line.
Sometimes it is desirable to use a ball having less resiliency and more weight than the sponge rubber ball 12. A heavier ball is better for throwing, as shown in FIG. 3, and when the batter becomes more experienced, a more realistic impression is felt so that the type of hit made can be determined. Such a ball 12' is shown in FIG. 5, having a resilient core 64 with a layer of string 66 wound about. A cover 68 encloses the ball and a diametrical hole 70 is drilled through the ball. A knot 72 joins the two ends of a length of elastic cord, the bight of which is threaded through a stress distributing pad 74 and has a first portion 76 extending through the hole in the ball and a second portion 78 extending outwardly therefrom. The regular line 14 is tied to the second portion 78 of the cord making it one connected line. The elastic cord is formed of elastic strands with a covering of cloth fabric braided suitably to permit expansion and contraction of the cord. As the cord elongates, the overall width of the strands decrease. Looking now at FIG. 6, the hole 70 has a diameter d and the first portion of line is reduced to fit within that dimension. The second portion of line which extends beyond the ball has an overall width W. The first portion of line extending through the ball is tensioned, reducing the diameter and enabling the line to be pulled through the ball. The second portion of line having been pulled through the ball, extends outwardly therefrom and expands to width W. A second stress distributing pad is unnecessary because the great r width of the second portion of line prevents the tension of the first portion of line from drawing the second portion of line back into the ball. Thus, the pre-tensioning of the first portion of line is maintained. The second portion of line, which is a loop, provides a resilient link to absorb the impact of shock when the line stops the ball. This reduces the shock transmitted from the ball, through the line to the handle 18 and ground anchor 22.
It will be understood that modification and variations of the embodiments of the batting practice device disclosed herein can be resorted to without departing from the spirit of the invention and the scope of the appended claims.
Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:
1. A batting practice device comprising:
a ball with a diametrical hole therein,
a line having a first portion disposed in the diametrical hole and maintained constantly in tension stress between opposite sides of the ball to prevent slippage of the ball thereon, and
a second portion extending from the first portion outwardly from the ball,
said ball being more resilient than the first portion of the line which has a length smaller than the ball diameter, and
means secured to the line on each side of the ball for balancing stress by compressing the ball in proportion to the tension in the first portion of line.
2. A batting practice device comprising:
a ball with a diametrical hole therein,
a line having a first portion disposed in the diametrical hole and maintained constantly in tension stress between opposite sides of the ball to prevent slippage of the ball thereon, and a second portion extending from the first portion outwardly from the ball,
said line being more elastic than the ball and having a width dimension that fits within the diametrical hole only when reduced to a minimum by tension elongation,
said line being formed from a short length of elastic cord looped with end portions tied together forming a knot, and
a stress distributing pad positioned between said knot and one side of the ball,
said first portion of line extending through the diametrical hole between opposite sides of the ball being maintained in tension by the diameter of the hole, and
said second portion of line extending outwardly from the ball forms an unstressed loop having resiliency to absorb the impact of shock.
References Cited UNITED STATES PATENTS 1,646,122 10/1927 Tidwell 27358.5 X 2,547,776 4/1951 Rankin 273-26 3,216,723 11/1965 Galezniak 273-58.5 X
FOREIGN PATENTS 140,131 8/ 1930 England.
RICHARD C. PINKHAM, Primary Examiner T. BROWN, Assistant Examiner US. Cl. X.R. 273-58