American engineer and railroad journal (1893) (14572883848)

Identifier: americanengineer68newy (find matches)
Title: American engineer and railroad journal
Year: 1893 (1890s)
Authors:
Subjects: Railroad engineering Engineering Railroads Railroad cars
Publisher: New York : M.N. Forney
Contributing Library: Carnegie Library of Pittsburgh
Digitizing Sponsor: Lyrasis Members and Sloan Foundation



Text Appearing Before Image:
than is absolutely necessary, andthe total clearance at the two ends of the cylinders has notbeen allowed to exceed f in., which has been distributed tothe best advantage. The cylinders are provided with i-in.drain cocks, connected so as to be worked by one lever that isnear the reverse lever. The pistons of the first intermediate-pressure and low-pressure cylinders are made of forged steel,dished, as shown in the engraving. The high-pressure pistonis made of cast iron and weighs exactly the same as that ofthe first intermediate-pressure piston. The second intermedi-ate piston is also made of cast iron and weighs the same asthat of the low-pressure piston, great care having been takenthat the reciprocating parts, connected with opposite cranks,should have the same weight in order to lessen the vibration.The packing rings used are A in. wide and ; in. apart, thethickness being A in. for the high-pressure, ± in. for the firstintermediate, and g in. for the second intermediate and low-
Text Appearing After Image:
AIR-PUMP FOR THIRD-CLASS TORPEDO BOAT U. S. BATTLESUIP MAINE. Vol. LXVIII, No. io.) AND RAILROAD JOURNAL. 459 pressure cylinders. These rings are made of hard cast ironcut obliquely and sprung in without a follower, the jointsbeing placed opposite. Each piston is accurately fitted to thebore of the cylinder, a play of not more than y^j in. beingallowed. The mild steel used in the manufacture of the pis-ton-rods and other forged parts has an absolute strength ofabout 80,000 lbs. to the square inch, with an elongation of 20per cent, in 2 in. The main valves for the intermediate-pressure cylinders arepacked by one cast-iron ring and follower, as shown, but thehigh-pressure valve is fitted accurately without rings to thebore of the valve-chamber, which is 3 in. in diameter. Thecross-heads are forged with the piston-rods. Each cylinder iscarried by four forged steel columns, except over the centralbearings, where two columns bear the weight between the twointermediate-pressure cylinders. T