The essentials of descriptive geometry . SURFACES 89 on a plane surface so that all the elements will coincide with theplane. In Fig. 73 is shown a cone lying in a plane so that theelement OX coincides with plane. If the cone be now rolledout the curve of the base will rectify itself on the line xx as theelements of the surface successively come in contact with theplane. The result, oxx, is called a development of the only developable surfaces are the single curved surfaces as. Fig. 73. these obviously are the only surfaces whose elements may bemade to lie in a plane without changing
The essentials of descriptive geometry . SURFACES 89 on a plane surface so that all the elements will coincide with theplane. In Fig. 73 is shown a cone lying in a plane so that theelement OX coincides with plane. If the cone be now rolledout the curve of the base will rectify itself on the line xx as theelements of the surface successively come in contact with theplane. The result, oxx, is called a development of the only developable surfaces are the single curved surfaces as. Fig. 73. these obviously are the only surfaces whose elements may bemade to lie in a plane without changing their relation to eachother. In practice, however, a number of warped and doublecurved surfaces are considered developable; this is made possibleby approximate methods of development which give patternswhich conform closely enough to the original surface for practicalpurposes. The bottoms of hemispherical water tanks are goodexamples of this fact. CLASSIFICATION OF SURFACES {PrismsPyramidsPolyhedrons Surfaces areeither Ruled. RuledSurfaces maybe Single Curved Surfacessuch as 3. Warped Surf aces such {Double Curved Surfacesare always surfaces ofrevolution such as Cylinders Cones Convolutes f CylindroidsI ConoidsI HelicoidsI etc. Spheres Ellipsoids Paraboloids H}T)erboloids Tori etc. 90 ESSENTIALS OF DESCRIPTIVE GEOMETRY Rt. Cir. 1. Single curved surfaces Cylinder Surfaces ofRevolution I. Ruled Sur-faces such as or asz. Warped Surface as Rt. Cir. Cone The hyperboloid of revolution
Size: 2633px × 949px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidcu3192400462, bookyear1915
