Patent ID: 6877927
Filing Date: 2005-04-12
Classification: F16D,Y10T

Abstract:
1. In a coupled shaft comprising a first and a second shaft segment which when coaxially assembled have a common central axis, said coupled shaft being transmissive of torque exerted by one of them, and resistive to axial separation in response to an axial separative force exerted on them, each said segment comprising a metal body having a terminal end, and adjacent to said terminal end a cylindrical peripheral wall coaxial with said central axis, an apparatus comprising: a coupler sleeve comprising a metal body having an internal cylindrical wall forming a passage therethrough, said internal wall so proportioned and arranged as to embrace said cylindrical peripheral wall of both of said shaft segments, and a first and a second end, and a longitudinally extending slot in said internal cylindrical wall, opening on at least one end of said sleeve, said slot having a dimension of width; an axially-extending groove in said peripheral wall of each shaft segment, said groove having a pair of axially extending, radially spaced apart side walls, spaced apart by a reference spacing and a dimension of depth; a rigid key fitted in each of said grooves having opposite sides laterally spaced apart to closely fit in a respective said groove and also in said slot in said sleeve, and a thickness greater than said dimension of depth whereby to project radially beyond its respective peripheral side wall into said slot; each said terminal end formed to complementarily engage the other terminal end to resist their axial separation from one another, each said terminal end including a transverse receiver recess and a tongue, said recess having a base wall extending across said central axis, a planar bearing wall which is neither parallel to or normal to the central axis, at an angle to said axis, a transition wall interconnecting said base wall and bearing wall as a smooth curve tangent to said bearing wall and base wall, said bearing walls being formed at the same said angle relative to the central axis, and which said angle is within the locking range of the material and its surfaces of which the bearing walls are made; a tongue wall contiguous to said bearing wall and extending toward the end of the tongue; whereby, when assembled together with the tongues in the recesses, the planar bearing walls can be brought together in sufficient surface contact, thereby resisting relative shear movement between them when an axial separative force is exerted on the completed shaft preventing axial separation of the segments, placement of the sleeve over the segments and keys preventing substantial relative rotation of the segments.