Abstract: A hydraulic controlling and actuating system has a hydraulic source having a high-pressure side and a low-pressure side and a hydraulic actuator connected to a controlled element and having one compartment pressurizable for moving the element into one of its end positions and another compartment pressurizable for moving the element into the other of its end positions.

Abstract: Stabilizers especially intended for mobile heavy equipment such as concrete delivery vehicles, mobile cranes and like vehicles are pivotally associated with the respective equipment and are downwardly pendent. For driving the vehicle, telescoping stabilizer legs can be moved clear of the ground by respective piston-cylinder units. In their operating condition, when the vehicle is parked, they stabilize the equipment and vehicle on the ground. The respective legs are connected at the frame in such a way that they can be swung into a substantially horizontal position when the vehicle is driven to another location.

Abstract: A pump assembly has a hopper adapted to hold a wet concrete mass and having a front wall formed with a front port centered on a front axis perpendicular to the front wall at the front port and a rear wall formed with two rear ports centered on respective rear axes perpendicular to the rear wall at the rear ports and generally parallel to the front axis. Respective piston pumps secured to the rear wall outside the hopper over the rear ports are operable to draw portions of the mass out of the hopper and expel them back into the hopper through the respective rear ports. An outlet conduit is connected to the front wall outside the hopper over the front port and a distributor pipe in the hopper has a front end fitted and aligned with the front port and a rear end engageable over and alignable with either of the rear ports. A buttress formation fixed on front end of the distributor pipe defines outside the hopper a buttress plane parallel to the front and rear planes.

Abstract: A concrete pump comprises a pair of separate pump assemblies each having a cylinder, a piston subdividing same into a piston-side front compartment and a rod-side rear compartment, and a piston rod connected to the respective piston and extending out of the respective cylinder through the respective rod-side rear compartment. The pump also has a liquid supply having a high-pressure side and a low-pressure side for supplying liquid under high pressure at the high-pressure side and for taking in liquid at the low-pressure side.