The Locomotive Of Today

80 The Engine : Connecting Rod Ends. <_> push-plate a gib is employed. The oil cup is forged and fitted. with a spring button and a pin, instead of worsted trimmings. The small end is of the forked type and each branch is fitted with a strap, which contains a hole in which the gudgeon pin works, these straps being held by cotters and gibs. No bushes are inserted in the holes, as this rod is used in com- bination with the crosshead shown at C and D, Fig. 15, where wearing caps are employed, which can be renewed when worn. The rod and cotters are of Steel, the small ends of wrought iron. The set screws are of Steel in all the above examples. D shows a pattern known as the “ marine” big end, from its similarity in shape to those usually employed on steam- ships. The rod end is swelled out to take two bolts, one above and one below the crank pin; these pass through a cap, forming the rod end. The bush is circular outside and in two halves, being prevented from turning by the two bolts just mentioned, which partially intersect it. Holes are pro- vided in the bearing, into which Babbitt metal is run, as shown. The bolts are of large diameter for strength, and holes are drillet! up the centre of the plain part to reduce the strength there to that of the screwed portion. The oil cup is solid on the cap, and as the top bolt prevents an oil hole from passing direct to the bearing, two holes are made passing round the bolt. The small end is of the strapped type, and has one bolt and adjusting cotter; two bolts are often provided with this form of small end. The rod itself is circular in section. Another small end with adjustable wedge is shown at E. The brasses are in halves, and a block of Steel bears upon the back half, this being in turn held by a wedge placed hori- zontally and drawn to necessary tightness by a screwed portion passing through a washer and having nuts upon it. As will be seen from the sketch, a safety catch is provided to prevent the wedge falling' out, should the locking device fail. Serious damage to the engine might ensue if this wedge were lost, for if the piston was travelling towards the back cylinder cover, either it or the piston would certainly be broken. At F other methods of making the two ends are shown, suitable for’outside cylindereel engines. It will be seen that the bearing is not nearly as large in diameter as in the previous examples, as, the crank pins being outside the wheels, it has only to tran smit the necessary turning power to them; whereas in inside cylindered engines the crank pin forms part of the axle, and in addition to the propelling has to take its share in supporting the weight of the engine. \This example has a forked “big end,” open at the end, and fitted with a block