Abstract: A reciprocating pump for pumping a fluid, especially for pumping a fluid such as UV ink which is subject to solidification when exposed to frictional forces. The pump has an internal displacement chamber with an inlet, and outlet, and a plunger which is reciprocally movable in the chamber. The plunger reciprocates through an axial passage in the housing at one end of the chamber, the passage being sized to receive the plunger with a clearance fit. First and second seals are positioned in the axial passage. Each seal is annular in shape and extends between the plunger and housing in sealing contact therewith. The pump housing is free from a bearing which contacts the plunger or guides its motion, such that the sealing contacts between the plunger and seals are the only contacts of the plunger in the housing.

Abstract: An ink bar is provided with a control device for bringing back printing ink into the ink duct (20) of a printing machine when required. The aim of the invention is to arrange all the essential function pieces in a space-saving manner, whereby said pieces are used for adjusting the ink level. The ink bar (1) is made from a hollow rod prifile having an undercut groove (4) on the lateral outer wall. Said groove serves for receiving cables (5). Discharge valves (8) and the supply device of an ink valve are arranged in the inner chamber of the rod profile. The ink valve is coupled to a sensor (9) and said valves are connected by means of the cable (5).