Coupling for connecting a hub and shaft

Claim 1

A coupling for making a connection secured against relative rotational and axial displacement, comprising, a hub member having keys and grooves at the internal circumference thereof and a shaft memeber in coaxial relation thereto having keys and grooves at the external circumference thereof, said hub member having a circumferential groove undercutting said keys thereof, a shaft insert member having keys of a lessor axial length than said circumferential groove disposed in said circumferential groove, fastening means attaching said insert member to said hub member for rotation therewith which includes axially extending bores in said insert and shaft members equally radially offset from the axes of said members, said bores being circumferentially offset from each other by an angle equal to one half the circular pitch of said keys, said fastening means including pin means extending in and between said bores, said shaft member having a central bore and a central counterbore, said insert member having a central threaded bore, said keys of said insert and hub members having adjacent abuttingly engageable surfaces when said pin means is installed in said radially offset bores and said keys of said hub member engages said grooves of said shaft member in a driving relationship, and a screw in said shaft member central bore threadedly engaging said insert member central bore to hold said engageable surfaces in abutting engagement.