Mechanical drive for a blind spline broaching machine

A method of mechanically driving a blind spline broaching machine, said method comprising the steps of:

• placing a helical ball screw having a central axis within a housing;
• attaching a helical ball nut to said helical ball screw;
• placing a ram in said housing a predetermined distance from said helical ball screw, said ram having a central axis extending in a direction transverse from said central axis of said helical ball screw;
• attaching a clevis link to the top of said ram;
• placing a pivot link between said helical ball nut and said clevis link;
• attaching an upper hub of said pivot link to said helical ball nut;
• attaching a lower hub of said pivot link to said clevis link;
• and
• placing a pair of guide ramps on said housing directly opposite to each other and straddling a symmetrically disposed pair of outboard hubs on said pivot link;
• whereby as said helical ball screw rotates and translates said helical ball nut thereon, said upper hub of said pivot link pivots and travels linearly with said helical ball nut while said lower hub of said pivot link translates linearly in a direction transverse to said central axis of said helical ball screw such as to reciprocate said ram between a beginning of travel position to an end of travel position.

In combination with a blind spline broaching machine of the type having a base, a multiple station loading/unloading rotary indexing table mounted to said base and a dual ram driven by at least one mechanical drive linkage, the improvement comprising:

• a housing mounted to said base and extending above said multiple station loading/unloading indexing table;
• a helical ball screw member mounted within said housing, said helical ball screw member having a central axis and an end portion extending in a direction away from said housing;
• a helical ball nut member mounted to said helical ball screw member for reciprocal movement along a linear path between first and second end positions;
• means for driving said helical ball nut member between said first and second end positions, said drive means having a housing mounted to said housing and an extended portion attached to said end portion of said helical ball screw member;
• a ram mounted in said housing about a central axis extending in a direction transverse to said central axis of said helical ball screw member, said ram having an upper end portion and an oppositely disposed lower end portion such that said ram reciprocates between a beginning of travel position to an end of travel position;
• a clevis link having one end mounted to said upper end of said ram;
• pivot means having one end attached to said helical ball nut member and an opposite end attached to said clevis link for pivotable movement whereby as said drive means drives said helical ball screw member to linearly translate said helical ball nut member therealong, said one end of said pivot means moves linearly with said helical ball nut member while said opposite end of said pivot means moves in a direction transverse to said central axis of said helical ball screw member from a first beginning of travel position to a second end of travel position;
• means for guiding said pivot means, said guiding means attached at one end to said housing and having at least a portion mounted contiguous said pivot means to guide said pivot means as said ram reciprocates from said beginning of travel position to said end of travel position;
• and
• means for pivotably attaching said one end of said pivot means to said helical ball nut member and said opposite end of said pivot means to said clevis link.