Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator . all belt lines which aregreater than 18° tangent to thisarc. Belt Holes. Very often abelt has to pass through a flooror partition. The holes throughwhich the belt runs should belarge enough to be sure that thebelt shall never strike the sides,but it is desirable that theyshould be no larger than is nec-essary to accomplish that , the holes should belaid out so that they may be cut
Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator . all belt lines which aregreater than 18° tangent to thisarc. Belt Holes. Very often abelt has to pass through a flooror partition. The holes throughwhich the belt runs should belarge enough to be sure that thebelt shall never strike the sides,but it is desirable that theyshould be no larger than is nec-essary to accomplish that , the holes should belaid out so that they may be cutin the right place and at theproper angle. Figs. 108 to 110show the method of locating . ?? ... a , -i a -i i o Fig. 107. Diagrammatic Layout for Cone Pulleys the position or the floor holes lor the various kinds of belts, the top only of the floor being Fig. 108 we have a common open belt. The circles repre-senting the pulleys are drawn, and the belt drawn around them. Ashort pitch line should be also drawn in each part of the beltwhere it passes through the floor. These parts of the pitch line aresimply lines parallel to, and halfway between, the lines which repre-. 128 MACHINE DRAWING sent the outer and inner faces of the belt. Next draw which represent the plan view of the pulleys, and drawthrough them the center line RS. From the points E and H, wherethe pitch line intersects the line representing the top of the floor,draw perpendiculars to RS, meeting it in points F and G. F and Gare the center points of the rectangles 1 2 3 If and 5 6 7 8, whichform the outline of the belt holes on the surface of the floor. The long dimension of the rectangles willbe parallel to the shafts on which thepulleys are located. After the beltholes are so found, the distances oftheir center lines to the right or leftof the lines T and X, respectively(which are the center lines of theshafts), can be measured on thedrawing, and the workman can markthem out on the floor
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Keywords: ., bookcentury1900, bookdecade1910, bookpublis, booksubjectmachinery
