US 3874663 A
A toy ball capable of increasing its own spin velocity so as to achieve a sharply curving trajectory involving a pair of weights mounted in a tube extending from wall to wall inside the ball. Springs urge the weights toward the center of the ball while cords attached to the weights extend outside the ball so the weights may be held in an extended position while throwing the ball.
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Description (OCR text may contain errors)
United States Patent 1191 Kahle TOY BALL  Inventor: William J. Kahle, Rt. 3 Box 12A,
Athens, Minn. 55040  Filed: Jan. 2, 1974 211 App]. No.1 429,486
[ Apr. 1, 1975 1,371,704 3/1921 Miller 273/128 CS FOREIGN PATENTS OR APPLICATIONS 108,100 '7/1917 United Kingdom 273/63 E Primary Examiner-George J. Marlo Attorney, Agent, or Firm-Charles A. Johnson [5 7] ABSTRACT A toy ball capable of increasing its own spin velocity so as to achieve a sharply curving trajectory involving a pair of weights mounted in a tube extending from wall to wall inside the ball. Springs urge the weights toward the center of the ball while cords attached to the weights extend outside the ball so the weights may  References Cited be held in an extended position while thl'OWlllg th 1,156,143 10/1915 Hyatt 273/63 F 1,188,488 6/ I916 Rehor 46/50 4 Claims, 2 Drawing Figures 12 31 3O 2 14 2 'IYY 1:: 27
28 s.) I 1 29 l9 TOY BALL BACKGROUND OF THE INVENTION It is well known in the prior art that a ball can be caused to curve in flight if it is given a spin when thrown. The amount of spin and, thus, the curve imparted to the ball is dependent upon the skill of the thrower. If a way could be found to increase the spin of the ball the curving effect would be enhanced. My invention accomplishes this end by providing a mechanism within the ball to increase its rate of spin automatically after it leaves the hand of the thrower. As a consequence, whatever the degree of skill of the thrower it will be substantially increased by using the invention herein described.
SUMMARY OF THE INVENTION Briefly, the operation of my new inventive ball utilizes the principle of the conservation of angular mo mentum. A mechanism is contemplated for changing the distribution of mass within the ball so as to concentrate it near the center after the ball is thrown. This necessitates a corresponding increase in spin velocity for the ball in order to maintain the angular momentum constant. The change in distribution of mass is achieved by mounting weights in a tube extending from wall to wall through the center of the ball. Suitable springs are connected to urge the weights towards the center of the ball. During throwing, the weights are held outward near the periphery of the ball by means of small cords or strings attached to the weights which cords extend out through the surface of the ball to be held in place by the thrower. After the ball is released the springs internal to the ball move the weights to the center and increase the spin and the curving effect. It may be seen therefore that it is an object of my invention to provide a toy ball having a surprisingly large capacity for curving in flight. Further objects and advantages will become apparent upon consideration of the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional view of the ball of my invention showing the weights pulled by means of cords to their maximum radial positions.
FIG. 2 is a second cross sectional view of the ball of my invention showing the final rest position of the weights as assumed after the ball is thrown.
DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2 it may be seen that the ball of my invention comprises a hollow spherical shell having a hollow cylindrical tube 12 positioned inside extending from one wall to the opposite wall generally through the center of the ball. Both spherical shell 10 and cylindrical tube 12 may be molded from a suitable plastic in a manner well known to those skilled in the art. Tube 12 is provided with a pair of slots 14 extending in from the right side of the tube in the drawings to a position close to the middle of tube 12. In FIG. 1 only the rearmost of slots 14 is visible. On the left half of tube 12 a pair of slots 16 are formed similar to slots 14 except in positions rotated 90 degrees about the axis of tube 12. Slots 14 and 16 provide guide paths for a pair of weights 18 and 19 which are adapted to slide along the length of tube 12. Weight 18 is provided with a pair of guide tabs 20 and 22 extending downwardly and upwardly slots 16. Weight 19 is provided with a similar pair of tabs 21 although only one tab 21 is shown in the drawings. Tabs 20, 21 and 22, extending outside of the slots, provide suitable anchoring points for a spring mechanism connected to urge both weights toward the center of tube 12. The spring mechanism for weight 19 is omitted in the drawings for clarity. Weight 18 is provided with a rubber band 24 extending from tab 20 around the right end of tube 12 and back to tab 22 so as to provide a strong force urging weight 18 towards the center of tube 12. A similar rubber band is mounted around the opposite end of tube 12 and connected to the tabs 21 extending from weight 19 so as to likewise urge the weight 19 towards the center of tube 12. In the rest position weights l8 and 19 assume the position shown in FIG. 2 with tabs 20, 21 and 22 resting against or near the ends of their respective slots 14 and 16.
Each weight has a cord connected to it allowing the thrower to hold the weights in their maximum radius positions. In the drawing the cord for weight 18 is shown as a cord 27 extending outside the spherical shell 10 through a hole 29 and back through a hole 31 and thence out again through a hole 32 where it wraps around the ball and is terminated by a tab 35. The cord 26 for weight 19 extends out through a hole 28 back into the ball through a hole 30 and out again through hole 32 also connecting to securing tab 35. The thrower grasps the ball in a conventional manner and throws it imparting a spin to it as would be done in throwing any conventional curve ball. The weights, however, are held in their extreme outward positions by pressing the fingers against securing tab 35 and holding it in the position shown in FIG. 1. After the ball and the tab 35 are released the weights slide to the center of tube 12 and the ball, under the action of rubber band 24 and the other rubber band not shown. This causes cords 26 and 27 to travel inward pulling tab 35 to the position shown in FIG. 2. As mentioned before, the change of mass distribution caused by weights 18 and 19 moving to the center of the ball causes an increase in spin in accordance with the principle of conservation of angular momentum thus increasing the curve of the trajectory dramatically.
In the preferred embodiment it is contemplated that the outer spherical shell 10 and tube 12 may be constructed from a relatively lightweight plastic whereas weights l8 and 19 could comprise, for example, lead. The ball of the preferred embodiment is also intended to approximate the dimensions of a baseball. With these constructional materials and the dimensions specified it has been found that the ball, after it is released will increase its spin more than three times over thus causing a very substantial increase in the curve of the trajectory. Another variation involves pulling only one weight out while throwing so as to create a temporary imbalance and erratic behavior in the flight of the ball. Still another alternative embodiment is one in which the weights are urged outwards towards the pheriphery of the ball and the cordsare reversed in direction so that the weights are held near the center during throwing. This causes the ball to dramatically decrease its spin velocity thus making it easier to throw a knuckle ball. As can be seen, there are many possible variations on the structure of my invention which do no depart from the spirit and scope thereof and thus we intend to be limited only to the appended claims.
l. A toy ball having the capability of changing its own spin velocity comprising a generally spherical outer shell and having apertures therein; an elongated tubular passageway mounted inside said outer shell and ex tending generally from one side of said outer shell through the center of said spherical outer shell and to the other side of said outer shell; movable weight means slidably located in said tubular passageway for altering the angular velocity of said outer shell according to changes of position of said weight means in said tubular passageway; spring means in cooperation with said weight means for urging said weight means towards a position at a first predetermined radius from the center of said outer shell; and tensioning member means connected to said weight means and extending outside said outer shell through said apertures for permitting a thrower to displace said weight means from said predetermined radius position to a second predetermined radius position and hold the weights in the displaced position while throwing the ball, the release of said tensioning member means and the movement of said weight means causing said alteration of angular velocity.
2. The ball of claim 1 in which said first predetermined radius position of said weight means is proximate the center of said ball.
3. The ball of claim 2 in which said tubular passageway is formed from atube extending from wall to wall inside said outer shell and further includes guide slots therein extending from the wall of the sphere to the center thereof; and said weight means comprise a pair of weights in said tube, each of said pair having tab means extending through an associated one of said guide slots for coupling to said spring means.
4. The ball of claim 3 in which said tensioning member means comprises individual cord means fastened to each weight, each of said cord means arranged for passing along said tubular passageway and through said apertures in said outer shell.