Universal joint

A universal joint comprising:

• a drive shaft and a driven shaft movable relative to said drive shaft over an angular range of 0.degree.-90.degree.;
• each of said drive and driven shafts comprising a hemispherical crown gear cluster at one end thereof, and a distal end;
• each said gear cluster comprising a circular array of hemispherical gear teeth;
• each adjacent pair of said gear teeth defining a ball-like socket between said each adjacent pair;
• each said circular array of said gear teeth defining a central hemispherical seat formed in the corresponding said gear cluster;
• a bearing means fixed in the said hemispherical seat of one of said drive and driven shafts receiving said gear teeth of said other of said drive and driven shafts and providing a bearing surface therefor when said shafts are angularly offset;
• and a closed casing enclosing said gear clusters of said drive and driven shafts, said gear clusters being maintained in meshing engagement within said casing;
• said casing maintaining said drive shaft rotatably and non-displaceably mounted therein and exposing said distal end of said drive shaft for connection to a driving means;
• said casing comprising a slot defining a 90.degree. range of angular movement of said driven shaft relative to said drive shaft, said distal end of said driven shaft extending outside said casing through said slot;
• said gear cluster of said driven shaft being rotatably and axially displaceably confined within said casing;
• said casing further comprising differentiated spherical bearing surfaces coextensive with said slot, said bearing surfaces supporting said gear cluster of said driven shaft and providing clearance for said driven shaft to move over all of said angular range.