Paint sprayer

摘要

A paint sprayer has a pipe (12) connecting the transport fluid to the spray head (15) via a change-over valve (14) connecting the delivery pipe to a drain pipe (16) which leads to a collecting tank (17). There is a colour-changing block (13) allowing differently coloured transport fluids or cleaning fluids to be connected. Directly behind the valve on the drain pipe is a transparent region (18) between a photoelectric sensor and a light source. The sensor evaluates the light absorption through the region and once a certain level has been reached, a signal is sent to the block to supply new fluid using an optic fibre.