Abstract: The present invention relates to a thick matter pump comprising at least two pump units alternating in the pump and suction mode, a delivery line, a suction line and a switching valve for switching between the pump units, one pump unit being connected in the pump mode by the switching valve to the delivery line, and one pump unit being connected to the suction line in the suction mode. The filling level of the pump unit in the suction mode is to be improved. To this end a pressure boosting device which acts independently of the pump units is provided in the area of the suction line for actively effecting a precompression of thick matter. The invention also relates to a suction/pumping method which is carried out by said thick matter pump.

Abstract: The present invention relates to a thick matter pump comprising at least two pump units alternating in the pump and suction mode, a delivery line, a suction line and a switching valve for switching between the pump units, one pump unit being connected in the pump mode by the switching valve to the delivery line, and one pump unit being connected to the suction line in the suction mode. The filling level of the pump unit in the suction mode is to be improved. To this end a pressure boosting device which acts independently of the pump units is provided in the area of the suction line for actively effecting a precompression of thick matter. The invention also relates to a suction/pumping method which is carried out by said thick matter pump.

Abstract: A device for discharging concrete having a flexible hose which is connected to a concrete supply line, preferably a concrete supply line of a concrete pump, the hose is provided with an input end which is associated with the supply line and through which the concrete conveyed through the supply line enters the hose and an output end through which the concrete conveyed through the hose leaves the hose for the purpose of discharge. The hose is adapted to be bent in at least one swiveling plane between a substantially straight initial position and a curved position, and also has a swivel for moving the hose from its straight initial position to its curved position.

Abstract: A apparatus for feeding concrete and other thick materials from a container into a feeding pipe by two feeding cylinders which are alternately connectable by a switching device to the container or the feeding pipe. The feeding pistons of the feeding cylinders alternately perform a suction stroke and a pressure stroke, with the average piston speed being at least temporarily greater during the suction stroke than during the pressure stroke. A continuous feeding flow is achieved in that during the switching period t.sub.u of the switching device the two feeding cylinders are substantially separated from the container at least temporarily and are short-circuited together to form a joint conenction with the feeding pipe. In this state, the one feeding piston is still finishing its pressure stroke while the other feeding piston already begins its pressure stroke at the same time.

Abstract: A device and method for pumping concrete, comprising a supporting arm projecting at an operating position and used for positioning the conduit end of a pump conduit, the supporting arm including supporting arm segments which each have arranged thereon at least one tubular segment constituting a component of the pump conduit.

Abstract: A concrete mixer is disclosed having a mixing drum and a drag body is mounted in the drum which has a drag surface positioned to at least partially come into contact with concrete in the drum during a measuring phase in the concrete mixing operation. A hydraulic driving circuit is provided to oscillate the drag body at least during the measuring phase. A pressure sensor is connected in the hydraulic driving circuit for measuring the actual pressure value in the hydraulic driving circuit which is indicative of the flow resistance on the drag surface during the measuring phase of the mixing operation.

Abstract: The invention relates to a device for sealing in the zone of contact between the mouths of alternately charging and discharging delivery cylinders of a concrete pump and a swinging pipe that is alternately movable to alignment in front of the cylinder that is discharging at the time. It comprises an annular seal body so supported at the mouth zone of the delivery cylinder as to be slidable between a sealing position projecting into the rear end portion of the swinging pipe and a withdrawn releasing position in which it is spaced from the swinging pipe so as not to interfere with its swinging. The seal body is maintained in its withdrawn position whenever the swinging pipe is moving, thus substantially avoiding abrasion.

Abstract: The invention relates to a concrete mixer truck having a mixer drum adapted to be rotated by the traction motor of the vehicle through an auxiliary transmission of the traction motor transmission. It is an object of the invention to ensure that the power supplied by the traction motor is effectively available for traction purposes under conditions of increased power demand, such as starting and accelerating, and/or that the torque of the mixer drum does not interfere with gear shift operations. To this effect the invention provides a control means adapted to disconnect the mixer drum rotating transmission from the traction motor transmission during predetermined travel conditions, i.e. under conditions defined by an increased power demand for locomotion of the vehicle. Also included in these conditions is each gear shift operation, as at this instance the torque of the mixer drum is prevented from influencing the rotary speed of the speed shift transmission.

Abstract: The invention relates to a concrete mixer truck having a mixer drum adapted to be rotatably driven, a water container, a water conduit leading from the container to the drum, and a water pump. An object of the invention is to prevent the quality of a properly composed mixture contained in the drum from being deteriorated by unintentional addition thereto of water from the water container. This is accomplished by the use of a measuring device determining the drive torque for the mixer drum and a valve disposed in the water conduit and controlled by said measuring device in such a manner that the water conduit is closed when the drive torque exceeds a selectively adjustable rated value corresponding at least to the drive torque required for the empty drum.

Abstract: The invention relates to a concrete mixer, particularly to a truck-mounted concrete mixer, comprising a drum and an actuatable additional mixer tool projecting into the drum from the bottom thereof substantially in the direction of the drum axis. A rotatably driven mixer tool of this type requires the employ of additional gearing, and a sealing assembly for the passage of its shaft through the drum bottom is very complicated and subjected to wear. In accordance with the invention, these disadvantages are avoided by the provision that the mixer tool is adapted to be moved in the axial direction. This permits a cylinder-piston unit to be employed as the drive source for the mixer tool. No gearing is required, and sealing as well as maintenance are simplified.

Abstract: The invention relates to a concrete mixer, in particular a free-fall mixer, in which the components of the concrete, in particular initially without water, can be intermixed by mixing elements by means of the rotation of a drum, wherein a vibrator is provided.The object of the invention is to make the mixing process easier and to save energy. This object is attained in that a vibrator which is switched on during the mixing process in order to reinforce it is disposed in the drum in the vicinity of the material to be mixed.

Abstract: A concrete mixer having a drum, which contains mixing elements, and at least one vibrator for imparting vibrational energy to the material which is to be mixed. The vibrator is drivable by means of the water used to make up the concrete. The water may be discharged in a pulsating manner from a vibrating body which is caused to vibrate by this pulsation, or it may rotatably drive an eccentric mass in the vibrating body.

Abstract: A system and method to control concrete production employs a loading station and a mixing truck having a rotatable mixing drum for travelling between the loading station and a job site. A control system is provided to insure that properly proportional ingredients loaded into the mixing drum at the loading station are mixed for a predetermined appropriate programmable interval of time, whether the mixing truck remains at the loading station or is in transit to the job site. The control system comprises a first portion installed at the loading station and a second portion mounted on the mixing truck, which portions are coupled together when the mixing truck is at the loading station. The first portion of the control system comprises a first time switch unit for controlling the entire time cycle (loading time and mixing time) in a first program and a second time switch unit for controlling only the loading time in a second program.

Abstract: This invention relates to apparatus for making ready-mixed concrete, comprising a plurality of transfer containers divided into separate chambers and adapted to be moved along a closed path to at least one filling station and a plurality of emptying or waiting stations, respectively, for temporarily containing cement, filling materials and possibly, water separately from one another and for transferring these materials to concrete mixer trucks, particularly to mixer trucks provided with positive mixing tools.

Abstract: A transit concrete mixer has a fill and discharge opening at the apex end of a conically tapered mixing drum. The drum is mounted for rotation on its axis at an angle relative to the horizontal which places the drum on an upward slant from its bottom to the fill and discharge opening. Internal helical blading of the drum moves the concrete into and out of the drum upon its rotation in opposite directions. A rotary mixing tool is mounted in the wide end of the drum on the axis of the latter in cooperative relation to the helical blading.