Appletons' cyclopaedia of applied mechanics: a dictionary of mechanical engineering and the mechanical arts . 0 to 350 feet per minute. They should be kept very true by being turned up, whichoperation may be accomplished by using a piece of gas-pipe as a turning tool. For very particularwork the grindstone requires to run so true as to necessitate the use of the black diamond or bort asa turning tool. The water applied to a grindstone softens it; hence the stone should not run in atrough of water, nor be allowed to stand with water applied to any part of it, for the reason thatthe softer parts
Appletons' cyclopaedia of applied mechanics: a dictionary of mechanical engineering and the mechanical arts . 0 to 350 feet per minute. They should be kept very true by being turned up, whichoperation may be accomplished by using a piece of gas-pipe as a turning tool. For very particularwork the grindstone requires to run so true as to necessitate the use of the black diamond or bort asa turning tool. The water applied to a grindstone softens it; hence the stone should not run in atrough of water, nor be allowed to stand with water applied to any part of it, for the reason thatthe softer parts wear away the quickest, and thus throw the stone out of true. The stone should bewetted from a pipe suspended above it, and provided with a cock to shut off the water when thestone is not in use. A useful device for truing grindstones is shown in Fig. 2225. It consists of a hardened steel-threaded roll held in bearings in a frame or stand, which is bolted to the grindstone frame in such aposition as to bring the thread upon the roll into contact with the face of the stone. The action is, GRINDSTONES. 73. that the tops of the thread crush off the stone in minute sections or granular particles. The mainstand or bottom piece is securely clamped upon the trough close to the face of the stone; then byturning the hand-wheel, the threaded roll is brought iuto contact with the face of the stone, and isallowed to remain so as long as is requisite to produce the desired result. The water is to be left asusual in the trough. When by long use the thread on the hardened roll becomes worn, it can be re-cut, which operation may be repeatedly performed. In grinding tools and instruments, a cutting edge is formed by the line of junction of the twof acets°at the point of a wedge. The angle of these two facets one to the other is determined by con-siderations of strength, and the shape of each facet either by considerations of strength or of a rule, the harder the material to be cut, t
Size: 1812px × 1380px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbenjaminpark18491922, bookcentury1800, bookdecade1880
