Abstract: Disclosed is an improved double acting piston actuator proportionally controlled by a pulse duration modulated control valve having a gas metering orifice in the actuator gas supply line to decrease gas consumption. The orifice reduces gas pressure applied to the actuator in proportion to the rate of gas use. The actuator has maximum gas consumption at mid range where actual load is a minimum and minimum consumption at actuator extremes where the load is maximum. The orifice thus supplies maximum pressure only when needed and reduces pressure and consumption under no load conditions.

Abstract: In a multipoint data communications system in which a central processing unit communicates with a plurality of remote terminals over a shared two-way communications facility, an automatic fault isolation circuit is provided to monitor energy levels originating at the several remote terminals. One or more energy level thresholds are incorporated into bridging locations through which incoming and outgoing address and message signals are distributed to, and collected from, remote terminals by way of the shared facility for the purposes of detecting noise buildups and isolating trouble conditions automatically without human intervention.

Abstract: An automatic device for feeding and welding T-profile button studs to a surface is provided with a collet for retaining and aligning an individual stud in place adjacent a workpiece. The collet is formed of relatively thin sheet metal and is effective to properly orient the fastener relative to the workpiece surface while minimizing the occurence or arcing in the area between the collet and the arc shield.