21. There are bevel gears driving coaxial contra-rotating double 4 blades screws to propel torpedo running straight under the water. 22. The most familiar kinds of bevel gears have pitch angles of less than 90 degrees and therefore are cone-shaped. 23. However, having inherited some worm-gear machinery from Lanchester Motors, BSA opted to specify worm drive rather than bevel gears . 24. Examples of such sections are the transverse section of bevel gear teeth and the normal section of helical teeth. 25. For a shaft-driven bicycle the gear ratio depends on the bevel gears used at each end of the shaft. 26. It differs from a geared differential by using several small ball bearings rotating between two plates, instead of bevel gears . 27. The overhead camshaft is driven by a vertical shaft through bevel gears , which also forms the armature of the dynamo. 28. The engines had separate cylinders on the crankcase and an overhead camshaft driven by a vertical shaft and bevel gears . 29. These engines had bevel gear shaft drive to the overhead camshaft, and were produced in round, square, and Mille crankcases. 30. Instead of the usual chain drive, the Century steamer employed shaft drive and a bevel gear drive, a very modern solution.
