Lugged coupling apparatus

Coupling apparatus for securing a shaft to an externally threaded member comprising:

• a cylindrical collar member having internal threads at one end to be threadedly received on the threaded member and at its other end a series of circumferentially spaced internal lugs extending radially inward to define a central opening and a series of circumferential apertures between the internal lugs,
• each said collar internal lug having a long longitudinal raised side and a short longitudinal raised side which define inwardly facing recesses therebetween, and
• a cylindrical shaft member having a plurality of circumferentially spaced external lugs at one end extending radially outward from the shaft,
• said shaft member having a diameter sufficient to be slidably received through the central opening of said collar member and said external lugs configured to be slidably received through the apertures of said collar member and pass over the short side and engage the long side of said collar internal lugs upon relative rotation between said collar and said shaft members, whereby
• when said collar member is threaded onto said threaded member in one direction said shaft external lugs will become seated in the recesses of said collar internal lugs and said shaft will be drawn into firm engagement on the threaded member to securely connect said shaft member to the threaded member, and
• when said collar member is rotated in the opposite direction relative to the threaded member said shaft external lugs will become unseated from said recesses and pass over the short sides of said collar internal lugs allowing said shaft to be removed from said threaded member and said collar.