15) Which type of bevel gear is used to connect shafts that are at an angle but not intersecting?

16) What is the machine element with a surface or groove formed to produce a motion to another part follower?

17) Which element having a projecting part of the cam imparts a reciprocating motion to the follower?

18) Which element of a cam is the distance one lobe will raise or lower the follower as the cam revolves?

19) Which is used to impart a reciprocating motion to the followers in a machine?