Abstract: A tennis ball retrieving and propelling device for placement on a surface having a ball delivery tube and a carrousel type ball retriever positioned below the ball delivery tube for receiving balls to be pneumatically transported to the ball delivery tube. The delivery tube is provided with a mechanism for constricting the effective cross sectional area thereof. The mechanism is provided with a releasing element for releasing the constriction to permit a ball to be pneumatically propelled through the tube. The mechanism includes a section of flexible tubing attached to the delivery tube, a cable surrounding the flexible tubing and a device attached to the cable for tensioning and releasing the cable to restrict and release a ball traveling through the flexible tube. The balls are pneumatically retrieved and propelled from the propelling device. The propelling device has elements for controlling the speed, azimuth and elevation of a ball delivered therefrom.

Abstract: A tennis ball retrieving and propelling device for placement on a surface having a ball delivery tube and a carrousel type ball retriever positioned below the ball delivery tube for receiving balls to be pneumatically transported to the ball delivery tube. The delivery tube is provided with a mechanism for constricting the effective cross sectional area thereof. The mechanism is provided with a releasing element for releasing the constriction to permit a ball to be pneumatically propelled through the tube. The mechanism includes a section of flexible tubing attached to the delivery tube, a cable surrounding the flexible tubing and a device attached to the cable for tensioning and releasing the cable to restrict and release a ball traveling through the flexible tube. The balls are pneumatically retrieved and propelled from the propelling device. The propelling device has elements for controlling the speed, azimuth and elevation of a ball delivered therefrom.