In a lens barrel (20), the depth of a first cam groove (b5) is substantially the same as the depth of a second cam groove (b4).

The travelling roller follows the above stated cam track.

The cam groove (b2) has a groove section (b2st) formed along the circumference.

The cam track (A) is circumferentially provided on a cam cylinder (F).

The integrated barrel loader/confiner includes an endless confiner cam track (68) and an endless pusher cam track (80).

The cam follower means (B) is engaged within the cam track (A), the cam follower means (B) being adapted to run in/ around the cam track (A) and be thrown between opposing walls (D, E) of the cam track (A).

The assembly includes a base (14) with a cam path (42).

The second tube has a first cam follower which engages with the first cam groove.

The first cam follower is attached at an inner end of the arm and engages the first cam track.

The second cam follower is attached to the arm at a position between the first cam follower and the crank and engages the second cam track.

Provided is a lens barrel capable of improving the design freedom for a cam groove.

A second cam track (41) is provided fast with the seat chassis for adjusting the inclination of the backrest and a second follower (47) is connected to the seatback and engaged with the second cam track.

The cam unit has a cam track which engages cam followers of mold assemblies of the molding machine to move the cam followers between a first position and a second position.

The cam groove in the lifting/lowering cam mechanism consists of a first cam part moving together with the slider mechanism and of a second cam part displaced relative to the first cam part.

The cam groove (24) has a permitted region (R1) and a restricted region (R2).