Abstract: A variable ratio master cylinder designed to operate, in one phase, to take up slack in a braking system by displacing a relatively large volume of fluid at a low pressure with minimum pedal travel and then gradually shift to another phase in which a smaller volume of fluid is displaced at a higher pressure with increased pedal travel to apply the brakes. The master cylinder includes a differential area metering valve which begins to open at a predetermined pressure in the pressure chamber and remains open above a predetermined second pressure and sealing means cooperative with at least one piston to seal off communication between the pressure chamber and the rear of the piston during the pressure stroke of the piston but to allow communication between said chambers on the return stroke of the piston for rapid return to the released state.

Abstract: Hydraulic control apparatus for automatic remote control of a hydraulic actuating ram. The apparatus has a double-acting slave cylinder connectable hydraulically to an actuating ram, and a double-acting master cylinder the piston of which is mechanically connected to the piston of the slave cylinder, the master cylinder being operable by hydraulic pressure supplied via a pilot-operated valve arranged automatically to reverse the stroke of the master ram at limits set according to the desired stroke of the actuating ram. The control apparatus may be used for controlling actuating rams which effect reciprocating pivotal movement about one or more axes of a water jet monitor.

Abstract: A hydraulic linkagae for transmitting reciprocating motion comprising a master unit, a slave unit, the master and slave units each comprising a pair of interconnected rod pistons reciprocally moveable within the cylinders in opposite directions by a force applied to the pistons, hydraulic lines connecting one master cylinder to one slave cylinder for transmitting motion from master to slave, a reservoir, a pair of one-way pressure valves mounted in opposite directions and in parallel between the reservoir and each master-slave connection so that volumetric increases in the fluid in the system will be forced out through a first valve of each valve pair and to the reservoir, and volumetric decreases in the fluid in the system will draw fluid from the reservoir through a second valve of each valve pair, thereby providing volume change compensation.

Abstract: A dual master cylinder has a secondary piston which when actuated pressurizes fluid in two secondary chamber sections with one chamber section increasing pressure at a faster rate than the other as the piston is stroked. The piston has passage means therein interconnecting the two chamber sections, a proportioning valve mechanism in the passage means acting to proportion fluid pressure from the one chamber section to the other chamber section after a predetermined pressure differential exists in the two chamber sections. A shuttle piston also mounted in the secondary piston is responsive to pressure generated in the one secondary chamber section and in the primary pressurizing chamber between the primary and secondary master cylinder pistons.