Direction-control device for a tennis-ball shooter

A direction-control device for a tennis-ball shooter comprising a mount plate extending on a Y-Z plane on which two motors are mounted on a first side thereof, said motors respectively driving a first wheel and a second wheel provided on a second side of said mount plate opposite to said first side, which together control a speed and a spinning extent of a tennis ball to be served, said direction-control device comprising:

• a first bar extending along a Z-axis and having two ends secured to said first side of said mount plate;
• a rotatably mounted shaft extending along an X-axis, having a first end engaged to a mediate portion of said first bar and a second end drivably attached to a first driving means, such that said first bar together with said mount plate is pivotable on a Z-X plane about a Y-axis and that said mount plate pivots on a Y-Z plane about said X-axis upon a restricted rotational movement of said first driving means;
• a second bar having a first end attached to said first side of said mount plate and a second end drivably attached to a second driving means, such that said mount plate pivots on said Z-X plane about said Y-axis upon a restricted rotational movement of said second driving means, said second driving means being mounted on a first motor seat which is mounted on said shaft to rotate therewith;
• and
• a third bar having a first end attached to said first side of said mount plate and a second end drivably attached to a third driving means, such that said mount plate pivots on an X-Y plane about said Z axis upon a restricted rotational movement of said third driving means, said third driving means being mounted on a second motor seat which is mounted on said shaft to rotate therewith.