254 KINEMATICS OF MACHINERY.
for instance we may use the following symbols for the forms named :
C+ Full cylinder, C~ Open cylinder,
S+ Screw spindle, S~ Nut,
K + Full cone, K~ open cone,
JT Plane cone (Cone having a vertex angle of 180.)
C Cylinder upon a general curvilinear base,
C + the same cylinder full,
C~ the same open,
P Prism upon a general curvilinear base.
We have chosen the symbol V for a vessel of any kind. By a suitable form-symbol we can make its meaning more definite in certain special cases, we can use V+ for the reciprocal of the vessel, that is, a body touching it all round upon its inner surface, so that V~ will stand for the vessel itself. V + , for instance, might represent a piston, V~ the cylinder in which it works.
Small letters similar to those of the class-symbols will also be used as form-symbols. They will be placed below and to the right of the former, and permit a distinct separation to be made between the forms of various elements, so as to shut out all meanings but the one intended. The following may serve as a few examples of this :
C z Cylindrical spur-wheel, and from it
Cf Spur-wheel with external teeth,
C^ Do. with internal teeth, or annular wheel,
K% Bevel wheel with external teeth, JT face wheel,*
H% Hyperboloidal toothed wheel.
HI Hyperboloidal face wheel,*
Cz Non-circular spur wheel with external teeth.
Pz Ptack.
C+ Cylindrical screw wheel.
T v Prismatic tension-organ, such as a flat belt.
Tp, Tp the same moving respectively towards or from its pulley.
T s Kope, T c wire, T z common chain, T r jointed chain.
- See Der Constructeur, 3rd. ed. p. 435 and 451.
