Abstract: The present invention provides an animal feeder comprising a hopper and a feed tray into which feed is gravity fed from the hopper. The hopper has an inverse funnel shape to prevent feed jams. The feeder is formed from two halves with a metering gate that meters the feed fed from the hopper to the tray. The metering gate has a limited swing with pegs mounted thereon to further agitate jammed feed inside the hopper as the animal feeds from the tray.

Abstract: A system for the inspection of the internal nature of a material utilizes an exciting ultrasonic field which is directed at a focal point to be inspected and heats that focal point. An ultrasonic sensing beam is directed through the material and through the heated focal point and is received by a transducer. A differential measurement of a propagation parameter of the sensing beam is accomplished by comparing a burst of its ultrasonic waves through the focal point without the heating effect of the exciting field, with an identical burst of the same duration, amplitude and frequency, but immediately after the heating effect has been accomplished by the exciting field. This system may be used to determine tissue characteristics, internal blood flow, and for other medical diagnostic functions.

Abstract: A teaching machine adapted to take account of the student's ability and progress operates with programmed cards and includes three stacking means, controlled conveyor means, display means and a student input means, such as a keyboard.