I. SPECIAL COLLECTIONS. 139 



185. Globoid screw aud screw wheel. 



Endless screw. 



186. Globoid screw. 



Applied in horse gins ; velocity ratio 1 : 12. 



Parallel Wheels. 



187. Parallel wheels with 24 teeth. 



Reuleaux. The teeth are revolutes. 



188. Parallel wheels with 6 teeth. 



Reuleaux. Would work also with 3 teeth. The teeth are ping. 



189. Parallel wheels with 5 teeth. 



Reuleaux. One wheel annular. 



190. Parallel wheels with 24 (pin) teeth. - 



Reuleaux. The parallelism is destroyed by displacing the axes. 



Planet Wheel Chains. 



191. Planet wheel chain. 



192. Planet wheel chain, a==oo . 



With excanching wheels. 



193. Planet wheel chain, a=&=oo . 



194. Planet wheel chain, with annular wheel. 



195. Planet wheel chain, b=c=<x> . 



196. Hyperboloidal endless screw. 



562. X. Belt-trains. 



197. Eeturning belt- train. 



Shows the alteration of velocity due to the slipping of the belt. 



198. Skew belt- train. 



Acts in one direction only. 



199. Belt-train with crossed guide pullies. 



The necessary tension is given to the belt at the instant it is thrown 

 into gear. 



563. XI. Slider-cam Trains. 



200. Sinoidic cams. Cardioids. 



Open cam with roller, pair-closure. 



201. Sinoidic cams. Cardioids. 



With second disc and centroid. 



202. Sinoidic cams. Cardioids. 



Pair-closure. 



203. Sinoidic cams. Polar sinoid. 



With centroid. 



204. Sinoidic cams. Polar sinoid. 



With centroid. 



