92 



MAC1 



Draw the views shown i i . and projn-t from one of them 



a third view. Scale 4 inches to a foot. 



EXERCISE 79 : A> <'. Draw the plan Hanoi 



this joint shown in ti. 78, and also draw an ion looking 



in the direction of the arrow. The parts at A and B are octagonal 

 in (Toss section. Scale 4 in< 



FIO 



EXERCISE 80: Locomotive Coupling Rod Ends. A form 

 of knuckle joint used on locomotive coupling rods is sh- 



in this case two rods meet and work on tlio same pin, as shown 

 at (a) fig. 79. Draw, in addition to \\n in li 



plan and a section through the axis of the pin. 



U inches to a foot. 



Would it be practicable to replace the two rods A B and B C by 



-. r M! \vorkm_' <>n tnc crank pins at A, 13, and C ? <iiv<- 

 reasons for your answer. 



