Zig-Zag Ball

This invention relates to a special kind of ball which moves in a zig-zag manner when rolled out on a flat horizontal surface. Such a ball is a toy or a sports requisite. As far as is known, a ball with similar characteristics has never been invented and/or made.

The object of this invention is to provide a ball suitable for an "anti-bowling" game, i.e. a game in which the aim is to roll the ball out in a bowling manner, with the intention to avoid obstacles distributed on a flat surface in front of the player.

The main characteristic of the zig-zag ball according to the invention is that the ball, rolling freely on a flat horizontal surface, travels along a sinusoidal path. This kind of movement is achieved by a mechanism placed inside the ball which causes the center of gravity of the ball to reciprocate in a repeating pattern as the ball rolls. One mechanism for achieving this result consists of a shaft with left and right threads traversing the hollow interior of the ball, a weight slidably supported on the shaft and a pin attached to the weight support which contacts the threads.

The same movement can be achieved by a mechanism consisting of a hollow endless spiral tube with a heavy metal ball running through it, or by a mechanism consisting of a system of balanced levers.

Additional features of the invention will be evident from the following description of a preferred embodiment of the invention, given by way of example only, and by reference to the appended drawing.

FIG. 1 is a vertical radial section view of a preferred embodiment of the ball of the present invention.

Referring to the drawing, the zig-zag ball according to the invention consists of a body 1, in which there is a shaft 2 with a left and right thread 4. A hollow cylinder 6 with a weight 3 and a pin 5 is slipped on the shaft 2. The pin 5 is in contact with the threads 4 engraved in the shaft 2.

While the ball is rolling, the body 1 and the shaft 2 are rotating, but the weight 3 does not permit rotation of the cylinder 6 slipped on the shaft 2. In that way, the weight 3, with the cylinder 6 and the pin 5, is forced to move axially along the shaft 2, from one side to another. When the pin 5 comes to the end of the right thread, it continues following the left thread (and vice-versa), which means that the weight 5, the cylinder 6 and the pin 3 start moving to the other side of the ball. The consequence of that axial movement is an oscillation of the center of gravity of the whole device, from one side to another. That reciprocating oscillation forces the rolling ball to enter left or right turns, which results in a zig-zag movement of the ball.