PNEUMATIC CONCRETE PUMP Russian patent published in 1996 - IPC

FIELD: civil engineering. SUBSTANCE: pneumatic concrete pump has cylindrical case with thrust lug in lower part along vertical axis, and hollow support part on back end surface of it. Rotary distributor in the form of a blind cylinder with coaxial shaft in support portion of the case and isolating partitions is placed in the case. The partitions form isolated ballast and two equal working chambers in the blind cylinder. Lugs reply to case thrust lug are made in the central zone of working chambers. The case is connected with its upper portion of the front end surface to loading concrete conduit. The case has a ring partition that covers the blind cylinder to form front and back isolated cavities. Additional pneumatic conduits are connected to the cavities. The blind cylinder may be moved in lengthwise direction along horizontal axis, and has the height smaller than the distance between case front end surface and end surface of support portion. Support portion of the case has ball stop placed on the axle of the blind cylinder. Blind cylinder shaft has a spring. The spring covers the shaft and is installed so to rest upon back case end surface with its one end, and the other end rests upon blind cylinder bottom through frictionless bearing. Loading concrete conduit is connected to upper portion of case front end surface along its vertical axis. Thrust lug has air discharge passage to open case back cavity to atmosphere. Inlet opening of the passage is of round shape and placed on the surface of thrust lug perpendicular to blind cylinder axle. Reply lugs are of L- shape. Each reply lug has an aperture with spring loaded ball valve. The aperture is coaxial to inlet opening of the thrust lug and is originated in the central portion of its shelf installed perpendicular to blind cylinder axle. The ball valve is extended outside the opening and faces inlet opening of the thrust lug. Distance between inlet opening of air discharge passage of the thrust lug and shelf of the reply lug installed perpendicular to blind cylinder axle is smaller than height of ball valve portion extended outside the opening in the reply lug. Depressurization booster mechanism is made in the form of two-arm lever. The lever is installed on the front end surface of the case. The case has an opening with overlapping elastic membrane. The opening is placed on the vertical axis of the front end surface of the case between loading concrete conduit and blind cylinder axle. One lever arm interacts to elastic membrane. Other lever arm is connected to cylindrical valve placed in the lower portion of the case. The valve overlaps opening to back isolated case cavity. EFFECT: high efficiency. 2 cl, 5 dwg