Abstract: A crossover relief valve for use in a hydraulic circuit connected to two single acting cylinders such as used to provide rearward force against opposite ends of a plow blade wherein excessive pressure against one end of the blade will allow fluid to flow from one cylinder to the other, the valve being of the sliding poppet and port type wherein the poppet has surface areas exposed to the pressure line to each cylinder of such a size as to open the valve for flow between cylinders when excessive pressure is applied to either and wherein when pressure is applied from both pressure lines against said surface areas the poppet will move a sufficient distance to open a port for return of hydraulic fluid to a reservoir.

Abstract: A forcing press for simultaneously pressing members onto opposite ends of a central member, such as railroad wheels onto an axle, wherein the press is prestressed by exerting balancing force against opposite ends of the axle prior to pressing the wheels onto the ends of the axle and including mechanism for simultaneously pressing the wheels onto the axle.