Abstract: Process suitable for providing a substrate with a protective coating based on chromium, including a chromium matrix in which solid particles are distributed. The process includes a step of electrodeposition of the coating carried out by passing an electric current between a cathode or cathodes of the substrate to be coated and an anode or anodes. The cathode(s) and anode(s) are immersed in an electroplating solution, wherein the electroplating solution is based on an aqueous solution including trivalent chromium obtained from the reduction of chromic acid by a reducing agent, and contains solid particles.

Abstract: A machine for automatically distributing piston rings and spacers into the grooves of a piston is disclosed. The machine comprises magazine tubes onto which stacks of the spacers and rails are threaded. The machine further comprises a widened bore in which the piston is seated as rails or spacers are automatically released from the tubes and threaded into the piston grooves.

Abstract: A method of manufacturing a hollow shaft having internal swellings of revolution is disclosed. Hollow shaft sections, each having at least one internal swelling of revolution, are consecutively formed in a substantially continuous cold extrusion process using a single punch 7. Tubular blank 1a is extruded through narrowed orifice 14 of die 8. Tip 10 of punch 7 is inserted into axial passage 11 of blank 1a and shoulder 13 of punch 7 engages a rear end of blank 1a to push blank 1a partially through narrowed orifice 14 and thereby compress the front end of blank 1a between tip 10 and narrowed orifice 14. Punch 7 is then removed from die 8 and another tubular blank 12 is introduced in die 8 with its front end in abutment with the rear end of deformed blank 1b.