412
MODERN STEAM PRACTICE.
Fig. 295.—Connecting-rod End for Cranked Shaft.a a, Brass ends. b, Cap. c c, Bolts and nuts.d, T piece forged on the piston rod. e } Oil cup.
helps to take the side strain off the bolts, but the generality ofmakers leave these surfaces quite plain. When the bottom end of
the connecting rod is con-nected to a journal inside of atrunk, it is necessary that thebrasses can be tightened upfrom the outside, and for thispurpose the eye of the rod isforged on solid, and bored andslotted out for the brasses;the rod is then bored out fornearly its entire length, for thereception of an inside Steel bar,which is fitted at the top witha cotter for tightening up therod against a steel plate letinto the top brass, the bottombrass having a projection caston, which fits into the centralhole in the connecting rod. This is a neat arrangement, and can-not be dispensed with when the brasses work in a crosshead held
quite rigid.
The old form of connectingrod, with straps, jibs, and keys,may in some instances be bene-ficially adopted, more especiallyfor the crosshead for doublepiston-rod return connecting-rodengines; in this arrangement,having the keys passing througha slotted-out part left in thebroad rubbing surface, with agroove formed in the condensercasting for the end of the keyto travel backward and forwardin, the distance from the centreof the journal of the crossheadto the plate on which the blockslides can be greatly reduced, which is a somewhat important con-sideration. A very simple form of connecting rod has half brasses