The Locomotive Of Today

156 The Framing, Wheels, etc.: Lubrtcators. over and down the pipe. T he top is fitted with a spring button, held upright by having a hollow stem fitting over the outsicle of the oil pipe, a slot in it allowing the pin freedom to move; a spring holds it up to the top of the covering plug. To charge with oil the button can be pushed clown with the point of the feeder, thus allowing the oil to run in. A further modification of this arrangement has the spring button and wick trimming instead of the bent pin. All of these forms may be usecl for either coupling or connecting rods. An American big end oil cup is shown at D. No wick is used, but a long lift valve fits in the oil way, having- a bevel seating at the top which prevents the passage of oil when the engine is standing; when the rod revolves the valve is lifted and oil reaches the bearing, the amount of lift being regulated by the screw at the top. Oil grooves cut in the faces of the bearings form channels by which the oil is spread over the whole area of the journal, etc. The slot links, etc., have simply a hole with an enlarge- ment at the top, no trimmings being required, as the move- ment is so slight that the necessary lubricänt can be retained on the bearing surfaces. The internal moving parts exposecl to steam pressure, such as the valves and pistons, have also to be lubricated, but require clifferent appliances. E shows a simple oil cup for supplying oil to the air brake pump cylinder. It is fixed on the steam pipe, and is in the form of a globe having- an inlet at the top, closecl when the chamber is filled by a screwecl plug, and an outlet pipe leading- from the surface of the oil down to the steam pipe to which it is connected, the lower end of the hole being reducecl in size to about ^-inch diameter. When steam is admitted to the pipe, a small quantity passes through the little hole up the oil pipe and into the oil globe; here it is condensed, forming water which, being heavier than the oil, gravitates to the bottom and raises the level of the surface of the oil above the down pipe. Oil is thus slowly displaced and passes down to mingle with the steam below, lubricating all the wearing surfaces with which it comes in contact. When all the oil has been replaced by condensed water the latter must be run off by slackening the plug at the bottom and more oil introduced. From its action this is called a “ displacement ” lubricator. The main engine cylinders are also sornetimes fitted with a somewhat similar oiler; but more commonly two kinds are usecl here—one the “ Turness,” supplying oil when steam is shut off, and the other the “ Roscoe,” when steam is on. A section of the former is shown at F. It is fixed so that the supply pipe is in free communication with one end of the