Endoscopic surgical instrument with a handle that can articulate with respect to the shaft

A surgical instrument, comprising:

• an end effector sized to be inserted through a trocar;
• an elongated shaft assembly coupled to said end effector, said elongated shaft assembly having a distal portion adjacent to said end effector for insertion into the trocar with said end effector and a proximal portion remote from said distal portion such that said proximal portion protrudes from the trocar when the end effector and distal portion are inserted therethrough;
• a control handle coupled to said proximal portion of said elongated shaft assembly, wherein said control handle is operable to articulate transversely with respect to said distal portion of said elongated shaft assembly, wherein said elongated shaft assembly comprises:
• a proximal shaft segment having a first distal end and a first proximal end, said first proximal end coupled to said control handle;
• a distal shaft segment having a second distal end portion coupled to said end effector and a second proximal end portion sized to protrude out of the trocar when said end effector is inserted through the trocar;
• and
• an articulation joint assembly attached to said first distal end of said proximal shaft segment and said second proximal end portion of said distal shaft segment;
• a distal drive shaft portion operably coupled to an actuator shaft in said end effector and operably supported within said distal shaft segment;
• a proximal drive shaft portion operably coupled to a motor supported in said control handle and operably supported within said proximal shaft segment;
• a drive shaft articulation joint coupled between said distal drive shaft portion and said proximal drive shaft portion to enable said proximal drive shaft portion to articulate relative to said distal drive shaft portion when said control handle is articulated relative to said distal shaft segment, said drive shaft articulation joint located within said articulation joint assembly coupling said proximal shaft segment to said distal shaft segment;
• a proximal spine tube segment attached to said control handle and received in said proximal shaft segment, said proximal spine tube segment operably supporting a portion of said proximal drive shaft portion therein;
• a distal spine tube segment pivotally coupled to said proximal spine tube segment and supported in said distal shaft segment and attached to said end effector, said distal spine tube segment operably supporting said distal drive shaft portion therein;
• and
• a push button assembly cooperating with said elongated shaft assembly and control handle to selectively lock said control handle in a desired position relative to said distal portion of said elongated shaft assembly, wherein said push button assembly is operable by and at least partially accessible to a user;
• wherein said push button assembly is operably supported on said instrument and movable between a locked position and an unlocked position, said push button assembly communicating with said distal spine segment such that when said push button assembly is in said locked position, said proximal spine tube assembly is prevented from articulating relative to said distal spine tube assembly and when said push button assembly is in said unlocked position, said proximal spine tube segment can articulate with respect to said distal spine tube segment;
• wherein said push button assembly is movably supported within a housing supported on the control handle, said push button assembly comprising:
• a push button portion;
• a yoke portion attached to said push button portion, said yoke portion supporting said proximal end of said proximal shaft segment therein, said proximal end of said proximal shaft segment supporting said proximal spine tube segment therein, said yoke portion having a first gear attached thereto;
• a cable wheel rotatably supported in said proximal spine tube segment that is supported within said proximal end of said proximal shaft segment supported within said yoke portion, said cable wheel having a second gear attached thereto for selective meshing engagement with said first gear;
• a right tension cable attached to said cable wheel and a right side of a proximal end of said distal spine segment;
• a left tension cable attached to said cable wheel and a left side of said proximal end of said distal spine segment;
• and
• a biaser between said housing and said push button assembly to bias said first gear into meshing engagement with said second gear, when said push button is not activated and to permit said second gear to unmesh with said first gear upon application of an activation force to said push button portion.