摘要 |
Apparatus for transferring an object between spaced locations comprises first and second articulated arms mounted on a support, each articulated arm having a drive member disposed for rotation about a drive axis and, pinned to it, a shorter driven member. A wrist plate with an integral holding platform is pivotally coupled to the driven members at spaced apart locations. The drive members are rotated from an initial position at which they subtend a first acute angle with the holding platform at an initial position through an intermediate position at which they subtend an angle of 180 DEG to a final position at which they subtend a second acute angle oppositely disposed from the first acute angle with the holding means at a final position overlying the drive axis. The wrist plate extends transverse of the extend-retract path for the holding platform. A pair of spaced pivot drums project from a surface of the wrist plate and distal bores of the first and second driven members are pivotally engaged with the pivot drums. A wrist link mechanism extends between and interconnects the distal ends of the first and second driven members such that equal and opposite rotational movements of the second driven member are imparted to the first driven member. This assures that as the holding platform moves between the initial and final positions, the orientation of the platform remains substantially unchanged. |