Coupling for end-to-end rotatable shafts

A coupling between two end-to-end rotatable shaft means for transmitting torque, said coupling comprising:

• an intermediate, torque-transmitting member disposed between and loosely related in male-to-female relationship with each of said shaft means, said intermediate member serving as one portion and the respective shaft means serving as the other portion of a pair of male-to-female joints spaced apart along the axis of said intermediate member, said female joints having an inner walls;
• cross bores disposed in the male portion of the respective joint and a translatable device disposed in each of the cross bores, said translatable device comprising end member and spring means therebetween for biasing said end members, each of said translatable devices extending entirely through the male portion of its respective joint and having said end members heated in torque-transmitting relationship upon formations in the inner wall of a female portion of the joint;
• each of said translatable devices being perpendicular to the axis of the male portion and lying in a plane perpendicular to the plane of the other of said translatable devices;
• the end members of each of said translatable devices being free to move simultaneously in unison in one direction or the other relative to said male portion, unrestrainedly, in said bores on a translational axis relative to the male portion of the joint in which it resides in response to lateral motion of the female portion of said joint upon which said end members are seated, and the male and female portions of each of said joints being free to pivot relative to each other about said translational axis of the translatable device associated with said joint;
• whereby, in the event of misalignment between said rotatable shafts, said intermediate member can undergo a free nutating motion, transmitting torque between said two shafts without transmitting side-loads therebetween.

A coupling for a pair of end-to-end shafts comprising:

• a pair of torque-transmitting hubs of rigid material disposed along the general rotational axis of the coupling;
• an intermediate torque-transmitting member of rigid material having an axis extending between said shafts;
• said hubs defining opposite ends of the coupling and each having an attachment means to enable it to be secured to its respective shaft;
• the opposite end of each hub having a central bore aligned with the rotational axis of the hub;
• said intermediate member having its respective ends disposed within the central bores of the respective hubs to form a pair of male-to-female joints with said hubs forming the female portions of said joints;
• the inner peripheral wall of each of said central bores having a pair of oppositely disposed torque-transmitting engaging means in the form of ball retaining formations, said formations lying on a cross axis perpendicular to the axis of the respective hub;
• said intermediate member having a pair of cross bores spaced apart along and perpendicular to the axis of said intermediate member, the axes of said cross bores lying in planes perpendicular to one another and positioned to register with respective pairs of said torque-transmitting engaging means in respective hubs;
• each of said cross bores extending entirely through said intermediate member and being sized to receive a freely translatable, torque transmitting device having ends seated upon said engaging means to transmit torque between the respective hub and the intermediate member in the manner that misalignment of said shafts and their respective hubs can be accommodated by free translation motion of said translatable devices relative to said intermediate member and pivoting motion between said intermediate member and said shafts about the axes of said translatable devices;
• a said translatable device of each translational device comprising a pair of bearing balls, said bearing balls being free to move simultaneously in one direction or the other along the axis of said cross bore relative to said intermediate member,
• said balls sized to be retained by said engaging means,
• said engaging means having the form of ball-retaining formations, with circular line-contact with said balls, and compressional springs disposed between the balls of each pair in a respective cross bore for biasing said balls into the respective ball-retaining formations and to permit rotation of said balls relative to the respective engaging means to accommodate rotation of said hubs despite parallel or angular misalignment of the respective shafts.