Abstract: A drywall tool provides tactile and audible feedback to the user, as a fastener is driven by frequent multiple blows, to indicate when the fastener is properly driven, and the drywall dimpled, without tearing the paper facing of the drywall. Dimpling apparatus and a firing valve for controlling the multiple blows are described. A cam is provided to withdraw the magazine follower from the last fastener in a strip to avoid jamming or damage by a descending driver. Tool apparatus permits use of lightweight, synthetic parts.

Abstract: A water-type spray application system employing a hydraulically-operated motor which is operated by the source of supply of the water or base carrier liquid and where the hydraulic motor dependently controls the amount of chemicals injected into the water system for application to lawns. The dependent chemical applications may be independently controlled and independently monitored as to the relationship of injection to the flow of water. The hydraulic motor employs a reciprocating piston and valving arrangement wherein the valving system operates to reverse the pressure differential across the piston upon reaching the end of the piston stroke so that a reciprocating action is obtained of a piston rod. The dependent metering systems involve an adjustable stroke mechanism which draws in liquids by suction and discharges fluids by pressure.

Abstract: A system for recovering energy from a pressured reactor comprising a reactor, a reciprocating engine connected to the reactor to receive reaction effluent from said reactor thereby driving the pistons of the reciprocating engine by expansion of the effluent and recovery apparatus downstream of the engine for recovering products from the effluent.The expanding reactor effluent is used to drive the pistons which are especially valved in conjunction with the effluent inlet port in the cylinder to facilitate handling the effluents, the pistons in turn operate a crankshaft through a crosshead which may power compressors or operate a generator to produce electricity. It is reasonable to expect recovery in a directly usable form, such as electricity, of over 25% of the energy theoretically available in the pressured reactor effluent in some cases.