PURPOSE: To enable ready mixed concrete accommodated in hopper to be discharged successively at an arbitrary amount from the discharge end of a screw conveyor by mounting a revolution mechanism, an elevating apparatus, hopper and screw conveyor on a self-running carriage.

CONSTITUTION: When a running motor 13 is activated via an operation board, a discharge machine can move in front and he rear direction on rails R, R by a self-running carriage 10. The electrical driving source in this instance is supplied thereto via an appropriate trolley or moving cable. As the revolution motor 23 of a revolution mechanism 20 is activated and thus a pinion 23a me shed with a fixed toothed gear 21 is driven, a rotation member 22 rotates and then an elevating apparatus 30, hopper 40 and screw conveyor 50 mounted on the rotation member 22 rotate integrally. And, when a cylinder 33 is expand ed and contracted, a sliding bracket 35 comes up and down via a moving frame 32 and chains 34, 34, with the result that the hopper 40 and screw conveyor 50 can be set at an arbitrarily high position.