Lift and carry mechanism and method

An apparatus for transferring parts between successive work stations in a multi-operation process, said apparatus comprising:

• an elongated shuttle assembly;
• linkage means coupled to said shuttle assembly for supporting said shuttle assembly along a horizontal axis from an overhead structure such that said shuttle assembly is supported above the successive work stations;
• first drive means supported from said overhead structure for driving said linkage means for moving said shuttle assembly along a generally rectilinear vertical path relative to the successive work stations, said first drive means comprising a first electro-mechanical device having an output shaft coupled to said linkage means such that rotation of said first output shaft moves said linkage means so as to change rotational motion of said first output shaft into rectilinear vertical motion of said shuttle assembly;
• a plurality of counter-balancing devices adapted to support said shuttle assembly from said overhead structure in said horizontal orientation;
• a carriage assembly having a plurality of carriages and having means for mechanically interconnecting said plurality of carriages in a predetermined space relation generally corresponding to spacing between the successive work stations;
• roller means for supporting said carriage assembly from a lower portion of said shuttle assembly, said roller means adapted to permit horizontal rectilinear movement of said carriage assembly relative to said shuttle assembly;
• work supporting means supported on each of said plurality of carriages for picking up and depositing of the parts;
• a rack member secured to said carriage assembly;
• gear train means secured to said shuttle assembly and adapted for intermeshing engagement with said rack member;
• second drive means supported from said overhead structure for driving said gear train means such that said rack member and said carriage assembly move relative to said shuttle assembly along said generally rectilinear horizontal path between the successive work stations;
• and
• controller means for selectively controlling actuation of said first and second drive means such that said rectilinear vertical path of said shuttle assembly and said rectilinear horizontal path of said carriage assembly can be continuously varied through a predetermined range of motion.

A method for transferring parts between successive work stations in a multi-station process, comprising the steps of:

• suspending an elongated shuttle assembly in a horizontal orientation from a overhead structure above the successive work stations;
• connecting a plurality of counter-balancing devices between said shuttle assembly and said overhead structure for supporting said shuttle assembly from said overhead structure;
• providing first electro-mechanical drive means for moving said shuttle assembly along a generally rectilinear vertical path relative to the successive work stations, said first electro-mechanical drive means being mounted on said overhead structure;
• interconnecting linkage means between said shuttle assembly and said first electro-mechanical drive means;
• actuating said first electro-mechanical drive means such that said linkage means changes rotational motion of a drive shaft associated with said first electro-mechanical drive means into translational vertical movement of said shuttle assembly;
• supporting a carriage assembly having a plurality of distinct carriages from a lower portion of said shuttle assembly, said carriage assembly adapted to be horizontally movable relative to said shuttle assembly;
• providing second electro-mechanical drive means for moving said carriage assembly relative to said shuttle assembly along a generally rectilinear horizontal path to transfer parts from successive work stations, said second electro-mechanical drive means being supported from said overhead structure;
• actuating said second electro-mechanical drive means for causing said rectilinear horizontal movement of said carriage assembly;
• controlling actuation of said first electro-mechanical drive means for permitting selective adjustment of said rectilinear vertical movement of said shuttle assembly within a predetermined range of motion;
• and
• controlling actuation of said second electro-mechanical drive means for permitting selective adjustment of said rectilinear horizontal movement of said carriage assembly within a second predetermined range of motion.

A method for transferring parts between successive work stations in a multi-operation process, comprising the steps of:

• interconnecting a plurality of counter-balance devices between a shuttle assembly and an overhead support structure for suspending said elongated shuttle assembly in a horizontal plane above the successive work stations;
• providing a first drive mechanism having a first rotatable output shaft;
• interconnecting pivotable linkage means between said first output shaft and said shuttle assembly;
• supporting a carriage assembly from a lower portion of said shuttle assembly, said carriage assembly having a plurality of individual transfer carriages corresponding in number and spacing to that of the successive work stations;
• attaching work-piece supporting means from each of said transfer carriages for engaging the parts;
• providing a second drive mechanism having a second rotation output shaft;
• interconnecting said second output shaft to said carriage assembly;
• actuating said first drive mechanism for changing rotational motion of said first output shaft into translational vertical motion of said shuttle assembly, said actuation defining a rectilinear vertical path for said shuttle assembly for picking up and depositing parts from the successive work stations;
• and
• actuating said second drive mechanism for moving said carriage assembly along a rectilinear horizontal path for transferring parts supported from said work-piece supporting means between the successive work stations;
• controlling actuation of said first drive mechanism for permitting selective continuously variable adjustment of said rectilinear vertical movement of said shuttle assembly within a predetermined range of motion for picking up and depositing parts from the work stations;
• and
• controlling actuation of said second drive mechanism for permitting selective continuously variable adjustment of said rectilinear horizontal movement of said carriage assembly within a second predetermined range of motion for transferring parts between the successive work stations.