In a nonimpact printer a device is provided for feeding a constant pressure fluid to a nonimpact printing head reciprocally movable to scan across a recording sheet. The feeding device is formed with a pair of identical first and second chambers connected respectively to first and second sections of a conduit through which the fluid is supplied from a source to the device. Fluid communication is established between the first and second chambers by a connecting channel which is smaller in cross section than the cross section of the first and second chambers and is connected to the printing head through a narrow passageway.
