Pigtail rotary joint

Claim 2

A rotary electrical joint comprising a hub member, a rotor member mounted concentric of said hub member for relative rotation, and electrical current transfer means disposed between said hub member and said rotor member in concentric relation therewith, said transfer means comprising a plurality of brush units carried by one of said members in adjacent circumferentially spaced relation and in intimate wiping contact with a continuous cylindrical surface of the other of said members, said brush units being carried by said one member for radial movement, means disposed between said one member and said brush units resiliently urging said brush units radially away from said one member, at least one pigtail directly electrically coupling each brush unit to said one member each brush unit includes a brush carried by a shoe with each brush being bonded to its respective shoe, and the bonding material between each brush being electrically conductive and meltable.

Claim 3

The rotary electrical joint of claim 1 wherein each pigtail is also bonded to a respective shoe, the bonding materials for said pigtails and said brushes being electrically conductive and meltable, the melting temperature of said bonding material for said pigtail being higher than the melting temperature of the bonding material for said brushes whereby said brushes may be removed and replaced without disturbing the connections between said brushes and said shoes.

Claim 4

The rotary electrical joint of claim 1 wherein said one member has a pair of end flanges having radially extending circumferentially spaced notches formed therein, said brush units having axial projections seated in said notches, and retainers carried by said end flanges in notch closing positions and limiting radial movement of said brush unit against the radial urging of said resilient means whereby said one member may be readily handled as a unit without release of said brush units.

Claim 5

In combination with a support and a relatively rotating member carried by said support, a rotary electrical joint between said support and said rotating member, said rotary electrical joint comprising an internal continuous cylindrical surface on said rotating member and a coupling member secured to said support and having brush units in wiping electrical current transferring contact with said cylindrical surface, said coupling member including a stationary hub, said brush units being disposed about said hub in circumferentially adjacent relation, securing means securing said brush elements to said hub in circumferentially restrained relation while permitting radial outward movement, resilient means disposed between said hub and said brush units urging said brush units radially outwardly into intimate contact with said cylindrical surface, at least one pigtail directly coupling each brush unit to said hub, and the bonding material between each brush being electrically conductive and meltable.

Claim 6

In combination with a support and a relatively rotating member carried by said support, a rotary electrical joint between said support and said rotating member, said rotary electrical joint comprising an internal continuous cylindrical surface on said rotating member and a coupling member secured to said support and having brush units in wiping electrical current transferring contact with said cylindrical surface, said coupling member including a stationary hub, said brush units being disposed about said hub in circumferentially adjacent relation, securing means securing said brush elements to said hub in circumferentially restrained relation while permitting radial outward movement, resilient means disposed between said hub and said brush units urging said brush units radially outwardly into intimate contact with said cylindrical surface, at least one pigtail directly coupling each brush unit to said hub, and the bonding material between each brush being electrically conductive and meltable.

Claim 7

The rotary electrical joint of claim 5 wherein said securing means includes said hub having a radially outwardly extending flange at each end thereof with said brush units being positioned between said flanges, said flanges having radial notches therein and said brush units having end projections positioned within saiD notches, and means closing the outer ends of said notches and limiting the outward movement of said brush units whereby said coupling member may be readily handled.

Claim 8

The rotary electrical joint of claim 5 wherein said means closing the outer ends of said notches include a ring around one of said flanges and a spider carried by the other of said flanges, said spider being in the form of a plate releaseably secured to said hub and having a radial leg for each of the notches in said other flange and aligned therewith, and a foot on each leg projecting axially into a respective notch at the outer end thereof.

Claim 9

The rotary electrical joint of claim 5 wherein each pigtail is also bonded bonded a respective shoe, the bonding materials for said pigtails and said brushes being electrically conductive and meltable, the melting temperature of said bonding material for said pigtail being higher than the melting temperature of the bonding material for said brushes whereby said brushes may be removed and replaced without disturbing the connections between said brushes and said shoes.