MechanismLongmans, Green, 1907 - 448 páginas |
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Términos y frases comunes
actuating addendum circle angle angular velocity angular-velocity ratio arc of approach attached axes axis belt bevel wheel block centripetal acceleration chain circular arc common normal connecting rod connecting-rod coupler crank arm crank pin crank radius crank shaft crosshead curve cutter cutting cycloidal cylinder described diameter direction displacement distance draw driving ellipse engine equal equivalent crank fixed centre gear horizontal intersect involute keyed kinematic kinematic chain lathe leading screw length lever line of centres line of stroke machine mandrel mean position meshes move number of teeth obliquity obtained oscillating P₁ P₁A P₂ parallel motion perpendicular pinion piston pitch circle pitch line pitch point plane pulley rack radii relative represent the velocity revolution revolutions per minute roller rolling circle shape shown in Fig sliding slot spindle spur wheel straight line tangent tool tooth transmitted turning pairs valve velocity diagram velocity ratio vertical whilst worm wheel
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Página 116 - DB be denoted by a and b respectively, so that a and b are the semi-major and minor axes of the ellipse which D would trace out if A accurately moved along a vertical straight line ; and let c denote the length of the link QD, so that the actual path of D is a circular arc of radius c. Moreover, let the inclinations of AB and DQ to the line of stroke of B be denoted by 0 and <j> respectively.
Página 416 - This gears with a spur wheel of 68 teeth keyed to the same spindle as a spur wheel of 12 teeth. The last wheel gears with a wheel of 50 teeth keyed to the same spindle as a wheel of 25 teeth, and the latter gears with a wheel of 54 teeth keyed to the chain-barrel spindle. The chain barrel is 16i
Página 351 - FIG. 388. transmitted by the frictional resistance to slipping. With noncircular plates, as shown in Fig. 387, the motion is transmitted by direct action. Again, taking the general case, if the profiles of the plates are such that the common normal at the point of contact always passes through the same point on the line of centres, the angular- velocity ratio is constant.
Página 380 - Amsler's Polar Planimeter, although different in its main features of principle and mode of action from the instruments just referred to, ranks along with them in involving the like imperfection of requiring to have a sidewise sliding action of its edge rolling wheel, besides the desirable rolling action on the surface which imparts to it its revolving motion — a surface...
Página 273 - The only kinematic condition therefore, that has to be satisfied is, that the common normal to the two teeth at the point of contact must always pass through the pitch point. If the...
Página 383 - As, from the nature of the apparatus, the axis of the disk and of the secondary registering or recording cylinder ought to be steeply inclined to the horizontal, and as, therefore, this bar, carrying the pencil, would have the line of its length and of its motion alike steeply inclined with that axis, it seems that, to carry out this idea, it may be advisable to have a thread attached to the bar and extending off in the line of the bar to a pulley, passing over the pulley, and having suspended at...
Página 407 - length " of the link. The perpendicular itself will be spoken of as the " central axis " of the link, and the axes of rotation at its extremities will be called the " hinge-lines." The mechanism now to be described consists of four links satisfying the following conditions : — (i.) Two alternate links have the same length a and the same twist a. (ii.) The other two alternate links have the same length b and the same twist /3.
Página 381 - ... or the cone and the cylinder are kept steady, or, in other words, without rotation on their axes, the ball can roll along them in contact with both, so that the point of rolling contact between the ball and the cylinder shall traverse a straight line on the cylindric surface parallel necessarily to the axis of the cylinder — and so that, in the case of a...
Página 382 - CyiinderThe longitudinal motion may be imparted to the ball by having the framing of the whole instrument so placed that the lines of longitudinal motion of the two points of contact and of the ball's centre, which are three straight lines mutually parallel, shall be inclined to the horizontal sufficiently to make the ball tend decidedly to descend along the line of its longitudinal motion, and then regulating its motion by an abutting controller, which may have at its point of contact, where it...
Página 381 - Society a brief description of the new principle as devised by me. The new principle consists primarily in the transmission of motion from a disk or cone to a cylinder by the intervention of a loose ball, which presses by its gravity on the disk and cylinder, or on the cone and cylinder, as the case may be, the pressure being sufficient to give the necessary frictional coherence at each point of rolling contact; and the axis of the disk or cone and that of the cylinder being both held fixed in position...