The Elements of Mechanism

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Longmans, Green and Company, 1886 - 345 páginas
 

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Página 41 - His counsel have contended for the exclusive monopoly of a method of lessening the consumption of steam and fuel in fire-engines, and that therefore would better answer the purposes of the patentee, for the method is a principle reduced to practice ; it is in the present instance the general application of a principle to an old machine.
Página 52 - E is the scape-wheel driven by the force of the clock-weight or spring, and mn the escapement, moved by the forked arm...
Página 131 - Two curves are said to be similar, when there can be drawn in them two distances from two points similarly situated, such, that if any two other distances be drawn equally inclined to the former, the four are proportional.
Página 145 - ... at each end. These cranks are placed at right angles to each other, so that when one crank is on a dead center, the other is midway between the centers. In consequence of this there is a much more uniform turning moment on the crankshaft than in a tandem compound engine, and hence the...
Página 210 - The insertion of a tooth in this manner prevents contact between the same pair of teeth too often, and insures greater regularity in the wear of the wheels. The tooth inserted was called a hunting cog, because a pair of teeth, after being once in contact, would gradually separate and then approach by one tooth in each turn, and thus appear to hunt each other as they went round.
Página 294 - AB, and sets the wheels in motion by the aid of a cord or chain wound partly upon the barrel and partly upon a sort of tapering drum called a fusee, and marked F in the diagram.
Página 331 - The winding action having ceased, the disks will return to their normal positions as the mechanism runs down. Instead of supposing A to make complete revolutions, let it oscillate to and fro through somewhat more than a right angle ; then B will oscillate in like manner, and will be held firmly by the opposition of the convex to the concave surface, except during the time that P is moving in the notch. GIB AND COTTER. A method of connecting separate parts of a machine. Sometimes one of the connected...
Página 125 - Pump-rods, and other parts of these engines, so as to move in perpendicular or other straight or right lines, without using the great chains and arches commonly fixed to the working beams of the engines for that purpose, and so as to enable the engine to act on the working beams, or great levers, both by pushing and by drawing, or both, in the ascent and descent of their pistons.
Página 320 - Q = a constant quantity. Further than this, the curves will have a common tangent at the point where they roll upon each other. Ex. Two equal ellipses which are centred on opposite foci will roll together. It is the property of an ellipse that the tangent at any point p...
Página 331 - ... shaped as in the drawing, is also fitted to the cover of the barrel, and is turned onward in one direction through a definite angle every time that the tooth P passes through one of its openings, being locked or prevented from moving at other times by the action of the convex surface of the disk A. In this manner each rotation of A will advance B through a certain space, and the motion will continue until the convex surface of A meets the convex portion E, which is allowed to remain upon the...

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