Patent GB-1193397-A (GB)
Title: Improvements in and relating to an Apparatus for Throwing Objects
Inventor: HURLIMANN PAUL
IPC: A63B69/40
Filed: 1968-11-13
Abstract: 1,193,397. Apparatus for throwing balls and other objects. P. HURLIMANN. 13 Nov., 1968 [21 Nov., 1967], No. 53931/68. Heading A6D. An apparatus four throwing objects, e.g. tennis balls, to a practising player, or clay pigeons for target shooting practice, comprises a rotary throwing means including wall means forming a spiral guideway having an inlet and an outlet, the inlet being positioned nearer the axis of rotation of the throwing means than the outlet, drive means for rotating the throwing means about the axis so that an object inserted through the inlet into the guideway is accelerated and driven through the guideway to the outlet by centrifugal force, closure means for closing the outlet, and actuating means operable to render said closure inoperative to permit passage of the object through the outlet. As shown in plan view in Fig. 1 and in side view (taken in the direction of the arrow III in Fig. I), in Fig. 3, a throwing means includes a circular wall 6 having an outlet 20, a pair of lateral walls 3 and 4 abutting the lateral edges of the circular wall 6 and a spiral wall or guideway I the lateral edges of which abut the end walls 3 and 4. An inlet 19 in lateral wall 3 opens into an inner portion of the guideway I and the outer end of the guideway is located in the region of the outlet 20 Which is laterally bounded by the walls 3 and 4 and circumferentially bounded by the axially extending edges of circular wall 6. The throwing means is rotated about an axis 22 by a drive shaft 7 secured to the lateral wall 4. The shaft 7 is mounted for rotation in a support 9 and has an end portion 73 projecting from the same and carrying a pulley 14. Support 9 is fixedly mounted on a tubular support 10 which is secured to a box plate 11. A fixed vertical supporting shaft 12 has a flange 13 and passes through suppart means 11, 10, 9 so that the same can be turned about the vertical axis of the shaft 12 together with shaft 7 and the throwing means 1 to 6 carried by the same. Pulley 14 on the free end of shaft 7 is driven by motor 18, through motor pulley 16 and V- belt 15. The rate at which the throwing means 1 to 6 is rotated is infinitely variable between predetermined limits since pulley 16 is in two parts one of which can be axially displaced against the action of a spring 80 on motor shaft 17. When the throwing means 1 to 6 is rotated in the direction of the arrow A, and a tennis ball is inserted through the inlet 19, the ball is driven by the action of the centrifugal force in guideway Ia along the spiral wall I to the outlet 20 which is normally closed by closure means 21. A control mechanism is described whereby the closure 21 is automatically opened when the outlet 20 is in different predetermined angular positions corresponding to different angles of elevation of the trajectory of the thrown ball. A second automatic mechanical control means is described for continuously and automatically varying the rotary speed of 'the throwing means 1 to 6, a third device for cyclically varying the azimuth angle of the throwing means, and a fourth device for controlling the rate at which balls are fed by gravity into the inlet 19 of the throwing means from a magazine.