Valve Gears and Indicators; A Manual of Practical Instruction in Valve-Setting, Use of Indicators, and Other Details of Steam Engine Operation Essenti (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ...pivoted at the ceuter of the cylinder. It transmits motion to each of the four valves through adjustable links known as steam rods or exhaust rods, according to whether they move the admission or exhaust valves. The valves which are shown in section in Fig. 60 oscillate on cylindrical seats, and the position of the rods is so determined that they give a rapid motion to the valve when opening or closing, and hold it nearly stationary when either opened or closed. The Reynolds hook is shown in detail in Fi;. 5U. The steam ana is keyed to the valve spindle which passes loosely through a bracket on which the hell-crank lever turns, and the spindle is packed to make a steam-tight joint where it enters the cylinder. Motion of the steam rod, toward the right will turn the hell-frank lever and raise the hook stud. The hook (from which the gear derives its name) pivoted on this stud, has at one end a hard ened steel die-with sharp, square edges, and at the other end, a small steel block with a rounded face. As the hook rises, the hook die engages the stud die which is fastened to the-steam arm, and one end of the steam arm is thus raised. This turns the valve in its seat and admits steam. As the hook continues to rise, its stud moves in an arc above the valve spindle, and the round-faced block at its left-hand end strikes the knock-off cam which causes the hook to turn about its stud and disengage the hook die from the stud die. In raising the steamjurm, the dashpot rod also is raised and a partial vacuum is created in the dashpot. As soon, therefore, as the dies become disengaged, the dashpot rod quickly drops under the force of this vacuum, thus turning the steam arm and closing the valve. The striking of the left-hand end of the hook against...