Abstract: A computer-controlled apparatus (1) for electrical testing of the make-and-break characteristics of electrical switches (15), including characteristics when the switches are actuated very slowly. The apparatus automatically feeds the switches into a test position (16), "breaks them in" by cycling them through many operations, and tests their switching parameters. The amount of hysteresis (54) between a switch actuator's (38) positions at actuation (30) and deactuation (56) is a criterion for sorting the switches. Switches are automatically classified and marked (14) according to their tested characteristics, and sorted into bins (28, 29). Any undesirable electrical "deadbreak" (an excessive transfer delay) during the operation of a double-throw switch's contacts is detectable by both a Timer Method and a Limit Switch Method, and faulty switches are reliably rejected. The apparatus increases accuracy in the testing of switches and reduces human errors such as those caused by fatigue.

Abstract: A rotating riffler for the purpose of withdrawing smaller laboratory-sized representative particulate samples from larger samples. This comprises a rotating disk having an interchangeable top plate of plastic foam having openings therein to accommodate sample containers. Where different size sample containers are employed, the plastic foam plate is changed to accommodate them. The rotating disk is mounted on a base containing a variable speed drive and is supported at the periphery by bearings rather than by the shaft. A slurry or dry volume of particles of which a smaller representative sample is required, is fed into a funnel-like device, then drops in a controlled flow into the sampling containers rotating below the funnel. "V"-shaped bridging devices having curved legs are attached between each pair of containers to prevent spilling.

Abstract: A method and apparatus are disclosed for the manufacture of foamed polystyrene particles of moderately great density, such as 3 to 25 lbs. per cubic foot (50 to 400 milligrams per cubic centimeter). Beads are fed by a constant-displacement auger to an expander vessel having the form of, in its lowest part, a cylinder with a vertical axis, and thereabove, of a frustrum of an inverted cone having a base angle of about 83.degree. to 70.degree.. Steam is supplied to the vessel in an appropriate, controlled manner. The vessel also contains stator bars, to break lumps and retard the rotation of the material in the vessel, and rotating bars, to provide the necessary agitation. Desirably, the equipment includes a discharge chute of adjustable location, to facilitate adjustment of the residence time and consequently of the density of the expanded beads being produced.