41. Instead they use trunk pistons, where the piston and crosshead are combined and so do not need a rod between them. 42. There are three main types of dies used in this process : annular ( or crosshead ), spider, and spiral. 43. The piston crossheads slid in guides, rather than being controlled by a parallel motion linkage like the majority of early locomotives. 44. Since the piston rod and crosshead was forged in one piece, the connecting rod small-end had to be forked. 45. Refrigeration was a two-stage process with a large Linde unit on the ground, and a crosshead compressor within the antenna. 46. Phillips'major contribution was in driving the crosshead concept forward to the point where it was adopted by screwmakers and automobile companies. 47. The reciprocating piston / crosshead / main rod / valve motion link is unbalanced and causes a fore-and-aft surging. 48. Air pump driven from each crosshead . | File : Durban Mill, Hollinwood-geograph . org . uk-216102 . jpg 49. Some crosshead engines had more than one cylinder, in which case the piston rods were usually all connected to the same crosshead. 50. Some crosshead engines had more than one cylinder, in which case the piston rods were usually all connected to the same crosshead .
