| 摘要 |
A head assembly for a manipulator has an inner part, an intermediate part, and an outer part adapted to hold a tool. The inner part can rotate on the manipulator about an inner axis defined thereby whereas the intermediate part rotates on the inner part about an intermediate axis defined by the inner part and intersecting the inner axis at an acute intermediate angle open away from the inner part. The outer part rotates on the intermediate part about an outer axis defined by the intermediate part and intersection the intermediate axis at a point offset from the inner axis and at an acute outer angle open away from the intermediate part. In no position of head assembly can any of the pivot axes-inner, intermediate, or outer-be coaxial with any of the other pivot axes. The intermediate pivot and drive includes a shaft extending along the inner axis from the inner part. In addition there is another shaft extending along the intermediate axis in the intermediate part and gears rotationally couple the shafts. The inner and intermediate parts meet at a joint defining with the inner and intermediate axes an inner swivel plane substantially perpendicular to the intermediate axis. The outer and intermediate parts meet at a joint lying in an outer plane defining with the outer and intermediate axes an outer swivel plane substantially perpendicular to the intermediate axis and meeting the inner plant at an obtuse angle. |
