Tennis practice device having pneumatic ball projector

Claim 1

A tennis game practice device comprising the combination of a simulated tennis court approximately 70 feet long and 30 feet wide and an air-powered tennis ball projecting machine for projecting tennis balls onto said tennis court; a tennis net positioned transversely of said court and placed approximately 20 feet from one end of said tennis court; crowning of said court along its longitudinal axis such that its center portion is approximately 6 inches higher than its sides; gutters adjacent each side of said tennis court which gutters slope downward towards said one end 20 feet from said net at a grade of approximately 33/4 percent, said gutters curving near said one end 20 feet from said net so that they come together to form a generally horizontal ball return conduit at a lowermost point of said court; enclosure means for preventing substantially all tennis balls hit by a player from leaving the court; a wall at said end 20 feet from said net having a slot therethrough and an image of target areas impressed thereon, said target areas simulating various points on a conventional tennis court; said tennis ball projecting machine having an aimable barrel extending through said slot in said wall for projecting tennis balls through said slot to selected areas of said tennis court; said barrel having means attached thereto for selectively imparting and varying spin and speed to a projected ball; a generally vertical riser having one of its ends coupled to said generally horizontal conduit; said aimable barrel being coupled to the other end of said riser by flexible means; air jet means coupled to said conduit, said riser and said barrel for projecting tennis balls therethrough; said tennis ball projecting machine being provided with timing means whereby operations of said machine are timed for automatically delivering balls to a player at selected time intervals; barrel elevating means for vertically adjusting said barrel; barrel traverse means for adjusting the horizontal direction in which balls are projected; said means coupled to said barrel for imparting vertical and horizontal spin to a projected ball; a ball projecting machine control center coupled to said machine; power means for transmitting power to said tennis ball projecting machine; a motor driven ball delivery timing rotor connected to the ball projecting machine for delivering balls from said conduit to said barrel at a pre-determined rate of delivery; an elbow having one of its ends coupled to said conduit and having its other end coupled to one end of said riser; a riser air jet solenoid valve switch triggered by said rotor for releasing air from said jet means coupled to said conduit for propelling balls from said conduit through said elbow and into said riser; and an elbow coupled between said riser and said barrel, one end of said barrel being coupled to one end of said elbow by said flexible means and the other end of said elbow being rotatably coupled to the other end of said riser.