Abstract: A mixer of the kind having a work head 50 comprising a rotor 60 rotatable within a stator 70 to cause liquid to flow through the stator and having a mixing and shearing effect in the liquid. The mixer has a motor 12 which is vertically movable within a housing 10 between a raised and a lowered position, by means of a handle 30 which rotates a cam 22 engaging the housing 12. The stator 70 is fixed to the housing 12 by rods 52, and the rotor 60 is fixed to the end of the motor shaft 40, so that movement of the motor 12 moves the rotor between raised and lowered positions. In the raised position the rotor has a mixing effect. In the lowered position the rotor is at the same level as an outlet 78 extending from the stator 60, and acts to pump liquid through the outlet.