Apparatus and method for locking two shafts

A coupling arrangement for two shafts rotatable about a common axis:

• an input shaft disposed for rotation about a axis of rotation and having a sixth locking portion and a seventh locking portion each extending radially outward and circumferentially about said axis of rotation;
• an output shaft disposed for rotation about said axis of rotation and having an eighth locking portion extending radially inward and circumferentially about said axis of rotation;
• a locking ring assembly movable between an unlocked position and a locked position along said axis of rotation;
• a first locking portion extending radially from said locking ring assembly circumferentially about said axis of rotation for engaging said eighth locking portion of said output shaft;
• a second locking portion extending radially from said locking ring assembly opposite said first locking portion circumferentially about said axis of rotation to engage said sixth locking portion of said input shaft;
• and
• a third locking portion spaced from said second locking portion along said axis of rotation and extending radially from said locking ring assembly opposite said first locking portion circumferentially about said axis of rotation to engage said seventh locking portion of said input shaft wherein said input shaft and said output shaft are coupled to one another for synchronous rotation when said second locking portion and said third locking portions are respectively engaged with said sixth locking portion and said seventh locking portion, wherein all of said first, second and third locking portions are operable to move along said rotation axis;
• and wherein said locking ring further comprises:
• a first locking member extending about said axis of rotation wherein said first locking portion extends from said first locking member;
• a second locking member extending about said axis of rotation wherein said second locking portion and said third locking portion extend from said second locking member;
• a fourth locking portion extending radially from said first locking member toward said second locking member;
• and
• a fifth locking portion extending radially from said second locking member toward said first locking member wherein said fourth locking portion and said fifth locking portion engage one another to guide relative movement between said first locking member and said second locking member.

A lock mechanism for selectively coupling two concentric shafts rotatable about a common axis of rotation comprising:

• a locking ring assembly movable along said axis of rotation of the two concentric shafts between a locked position and an unlocked position:
• a first locking portion extending radially from said locking ring assembly circumferentially about said axis of rotation for engaging a first of the two shafts;
• a second locking portion extending radially from said locking ring assembly opposite said first locking portion circumferentially about said axis of rotation for engaging a second of the two shafts;
• and
• a third locking portion spaced from said second locking portion along said axis of rotation and extending radially from said locking ring assembly opposite said first locking portion circumferentially about said axis of rotation for engaging the second of the two shafts, wherein all of said first, second and third locking portions are operable to move along said rotation axis, wherein said first locking portion is further defined as being operable to move along said rotation axis relative to said second and third locking portions.

A method for coupling two shafts rotatable about a common axis comprising the steps of:

• moving first, second and third locking portions of a locking ring assembly along an axis of rotation of two rotatable shafts between a locked position and an unlocked position including first moving the first, second, and third locking portions together a first predetermined distance along the rotation axis and second moving less than all of the first, second, and third locking portions a second predetermined distance along the rotation axis, said second moving step occurring after said first moving step;
• engaging a first of the two shafts with the first locking portion extending radially from the locking ring assembly circumferentially about the axis of rotation;
• engaging a second of the two shafts with the second locking portion extending radially from the locking ring assembly opposite the first locking portion and circumferentially about the axis of rotation;
• and
• engaging the second of the two shafts with the third locking portion spaced from the second locking portion along the axis of rotation and extending radially from said locking ring assembly opposite the first locking portion circumferentially about the axis of rotation.