for producing a continuous thick matter flow is illustrated in fig1 a first pump unit 1 is connected via a switchover device 7 to a delivery line 5 a second pump unit 2 is connected to the suction line 4 and a charge pressure device 3 fitted thereon the necessary connections of the pump units 1 2 can be produced alternately via the respective position of a slide 17 of the switchover device 7 a storage container 9 flange mounted to the suction line 4 can be separated from the suction line 4 by means of a slide gate valve 8 the delivery line 5 is typically a delivery line system consisting of piping a distributor mast or fixedly laid lines at a construction site the first pump unit 1 pushes thick matter into the delivery line 5 when the slide 8 is open the second pump unit 2 and the charge pressure device 3 suck thick matter from the storage container 9 until the piston of the delivery cylinder 12 of the sucking pump unit 2 overruns the switching point 10 the switching point 10 prompts the closure of the slide 8 and launches the fully filled charge pressure device 3 which pushes thick matter against the closed slide gate valve 8 and thus into the sucking pump unit 2 until this is largely or completely full the thick matter located therein is compressed and the delivery piston 12 has reached the end position thereof with the switching point 11 the switchover device 7 is actuated by this switching point 11 the first pump unit 1 is.