Patent attributes
A step movement mechanism is provided, which comprises a driven member and driving means, which drives the driven member. The driven member is formed with a plurality of equally spaced first concave cambered surfaces and a plurality of equally spaced force-bearing surface pairs. The two surfaces of each surface pair face each other. The driving means comprise a drive source to rotate a cam gear. The cam gear carries a rotation pin and stop means both rotating with the cam gear. The stop means are in contact with one of the first concave cambered surfaces when the step movement mechanism is in a stop position so as to prevent the driven member from moving. The rotation pin is temporarily in contact with one surface of the force bearing surface pair so as to move the driven member by one step when the cam gear rotates one revolution in either direction.
