The Locomotive Of Today

The Framing, Wheels, etc. : Lubricators. 155 grease or tallow—has to be delivered to the exact part intended by means of one or other of various forms of lubricator. For oil the simplest is the oil cup, shown at A, Fig. 32 It is of cast iron or brass, and has a tube inside it reaching nearly to the top, and leading down to the bearing requiring' the oil ; the top of the cup is slightly reduced in size by having a lip cast round it to prevent the oil from splashing out when the engine is running. A wick trimming is placecl in the tube, of such a tit that the oil may pass in the desired quantity to the bearing. The trimmings are either of the “plug” or “ tail kind, according to the position of the part lubricated. Flug trim- mings are fitted to oil cups, which are subject to violent move- ment, such as those on the big and small ends of connectingrods, eccentric straps, etc., and are made by taking a loop of copper wire and wrapping strands of worsted round it, then pushing the whole into the oil hole, leaving the top of the worsted about } inch below the top of the pipe, and the bottom about 1 inch from the bearing. A loop formed of the copper wire prevents the trimming from being worked down the pipe. As the oil is thrown about by the movement of the part to which it is fixed some of the oil lodges in the recess above the plug, and slowly percolates through it to the bearing. W hen the part to be lubricated has no movement apart from that of the whole engine, as slide bars, axle boxes, etc., “tail trimmings are used. They differ from the other form by having- the ends of the worsted hanging over into the oil reservoir to lift or “ syphon ” the oil over to it by capillary attraction. Plugs are more economical as they only supply oil when the engine is running and needed ; therefore they are now used wherever possible, and often in places where “ tails were at one time employed. On connecting and coupling rods the oil cup is usually forged on and machined up to the required shape. At B an oil well for a connecting rod big end is shown. The well is bored out and the internal pipe left standing up in the centre with a hole drilled down to the bearing. The top of the lubricator is closed by a screwed cap having a hole, in the top for the admission of air. To prevent the oil from being thrown out as the rod revolves, it is usual to close this hole with a plug of cork or cane, which being porous admits sufficient air to allow the oil to pass out. A modification of this oil cup for a coupling rod end is represented at C, forged solid as before, but instead of the wick trimming and porous plug, a bent pin hangs over the oil pipe, with one end inside and the other out. As the rod end moves the oil splashes on to the pin and works