File:Appletons' cyclopaedia of applied mechanics- a dictionary of mechanical engineering and the mechanical arts (1880) (14593477517).jpg

Identifier: appletonscyclopa02dapp (find matches)
Title: Appletons' cyclopaedia of applied mechanics: a dictionary of mechanical engineering and the mechanical arts
Year: 1880 (1880s)
Authors: D. Appleton and Company Benjamin, Park, 1849-1922
Subjects: Mechanical engineering -- Dictionaries
Publisher: New York, D. Appleton
Contributing Library: Mugar Memorial Library, Boston University
Digitizing Sponsor: Boston University

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ed by a link to the valve-stem, and thus gives motion tothe valve! The valve is caused to rise in the up-strokc by means of the rocker JV, and its connec-tions, through the inclined plane. The steam is thus admitted to the top, which drives down thepiston, while the valve and connections follow by gravity, thus reducing considerably the friction andwear upon the valves. In very quick work the fall of the valves may be accelerated by the aid of aBpring; or it may be retarded in heavy work by friction-springs, so as to obtain a heavier blow by afuller admission of steam. For general work, however, the arrangement shown is perfectly effective,and as the rocker N is hung upon the adjustment lever P, any required variation can be obtained bythe movement of the lever. Single blows can be struck with any degree of force, or a rapid succes-sion of constant or variable strokes may be given. The anvil 0 rests upon a separate foundation, in order to reduce the effect of concussion upon the 2285.
Text Appearing After Image:
frame. Fig. 2284 illustrates the arrangement. The bed is long, extending beyond the hammer oneach side so as to give plenty of area, and the ends are left open for convenient access in case theanvil should settle and require readjustment. The Sellers Steam-Hammer.—In a single-acting steam-hammer the gross force of the blow struckis that due to the weight of the die or hammer, the piston-rod and piston, and the height from whichthey fall; the force of the blow being regulated by varying the length of the stroke, or, in other HAMMERS, STEAM, DIRECT-ACTING. 95 words, the height to which the hammer is lifted by the steam. In many steam-hammers of modernconstruction the steam is admitted to both sides of the piston, so that the force of the steam uponthe upper side acts to increase the force of the blow, the latter being modified by regulating thepressure of the steam above the piston, and for very light blows by throttling the exhaust-steam be-low it, as well as regulating the stroke of

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