The present invention also relates to a drive mechanism for driving a load which comprises a first rotary member which provides an essentially uniform rotary motion, with the first rotary member comprising a drive pin; and a second rotary member operationally associated with a load which is to be driven. The second rotary member comprises a plurality of radially extending slots which are curved along a substantial portion of a length of the slots; with each of the slots being engageable with the drive pin of the first rotary member during a rotation of the
first rotary member, to provide an incremental angular rotation to the second rotary member while a drive pin load on the drive pin and forces applied to the load which is to be intermittently driven remain in control.