Presentation of parts

A method of accurately positioning parts precisely in a predetermined location and orientation, comprising:

• placing a part against a reference surface on a base;
• energizing an actuator to move a cable in one direction along its length around a plurality of pulleys;
• moving a pair of positioners in opposite directions toward said part attached to said cable, by moving said cable;
• engaging opposite sides of said part with said positioners and camming said part up along a ramp surface on each of said positioners and engaging opposite ends of said part with an abutment on each of said positioners to lift said part to a reference position and center said part between said positioners;
• gripping said part while in said centered position;
• and
• energizing said actuator to move said cable along its length, in the direction opposite said one direction, to move said positioners apart and release said part.

A cable-operated opposed motion device, comprising:

• a cable actuator attached to a base, said cable actuator having a cylinder and a piston disposed coaxially in said cylinder;
• a first pair of pulleys, one at each end of said cylinder;
• and a cable trained around both pulleys and connected to said piston along said axial center of said piston;
• a second pair of pulleys attached to said base approximately in line with said first pair of pulleys;
• said cable trained around both pulleys of said second pair and crossed between said two pairs of pulleys in a FIG. 8 configuration;
• two carriages, one each connected to the same run of cable between said first and second pair of pulleys;
• whereby pressurizing said cylinder on one side of said piston moves said piston and said cable in one direction axially in said cylinder, moving said carriages toward each other;
• and
• pressurizing said cylinder on the other side of said piston moves said piston and said cable in the opposite direction axially in said cylinder, moving said carriages away from each other.