TOOTHED WHEELS 



Total height of tooth . - * - 



Height of tooth abort pitch !im-- 



Depth of tooth below pitch UM -/- 



. 



sectional 

 inohas, 



46 : Spur H'M. - Fig. 4ft -hows the Novation and 

 l plan ,* of a eaat iron spur wheel Thcdiameter 



ui i incho.. anU the "he t,th u 1) 



o thai them will be 50 U whw.1. The whe*l ha> 



* 



tix arms. Draw a complete elevation of the wheel and a half sec- 

 tional plan, also a half-pUi any section. Draw also a 

 cross section of one arm. Scale 4 inches to a 



Jfortftstf WkoeU. When two wheels gearing together run 

 at a high speed the teeth of one an* made of wood. These 

 teeth, or cogs, as they are generally called, have tenons formed 

 o mortises in tho rim of the wheel This 

 wheel with the wooden teeth is called a morfiw irfaf/. An 

 example of a mortise wheel is shown in fig. 46. 







