82 OUTLINES OF NATURAL PHILOSOPHY. 



ference of the wheel as a base, beginning at the 

 point B, and intersecting CE in F. Then BF is 

 the figure of one face of the tooth, and in the same 

 manner may the other FL be determined. When 

 one tooth is formed, it may serve as a model for 

 the rest. 



The teeth of the pinion are to be determined in 

 the same manner ; the radius of the generating 

 circle being made equal to half the primitive ra- 

 dius of the wheel. 



See CAMUS on the Teeth of Wheels, Article 548, p. 53. 

 et seq. of the English translation. 



Toothed wheels are frequently employed for changing 

 the direction of motion : the directions of their axes 

 are then inclined to one another, and the parts of 

 their rims where the teeth are placed, are cut into 

 frustums of cones, each of which has its vertex in 

 the intersection of the axes of the two wheels. 

 Wheels of this kind are called bevelled, or crown 

 wheels. 



141. The figures of the teeth of bevelled wheels, 

 are determined by an epicycloidal surface, generated 

 by a straight line, on the surface of a cone, while 

 the cone rolls on the conical part of the wheel, 

 its vertex being in the point where the axes of the 

 wheels intersect. The line on the surface of the 

 revolving cone passes through its vertex. 



Consult 



