US 4,813,845 AGranted

Object transport apparatus

AssigneeAdvanced Control Engineering

InventorDanny C. Swain

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Abstract

An object transport apparatus (10) is provided for the purpose of transporting an object (19), usually a semiconductor wafer, to various points within a planar circular zone (Z). The transport apparatus (10) includes a motive power subassembly (12) for generating rotational motion and delivering it to an arm subassembly (14) rotating about an elbow axis (20) and, through an eccentric drive subassembly (110) to a hand subassembly (16) adapted to support to wafer (19). The hand subassembly (16) rotates about a wrist axis (21) which is parallel to but displaced from the elbow axis (20) in an independent fashion from the rotation of the arm subassembly (14). The eccentric drive subassembly (110) incorporates complimentary pairs of cam drivers (111, 112) connected by cam linkages (120, 122) to deliver rotational motion from the elbow axis (20) to the wrist axis (21). The apparatus (10) is particularly useful in the semiconductor manufacturing field where it may be used for a variety of tasks, primarily in delivering wafers (19) from one workstation position to another in a precisely controllable manner.

An object transport apparatus adapted to transport an object among points located in a planar zone, comprising:

a motive power subassembly including a first positioning motor and a second positioning motor;
an arm subassembly rotatable about an elbow axis by said second positioning motor;
and
a hand subassembly adapted to carry objects, attached to the arm subassembly at a wrist axis, displaced from said elbow axis, being rotatable about said wrist axis by said first positioning motor, with rotational force delivered by said first positioning motor being translated by an eccentric drive subassembly, said eccentric drive subassembly being situated within the arm subassembly intermediate said first rotational motor and the hand subassembly, and being adapted to deliver rotational motion of a hand drive shaft concentric with said elbow axis to a wrist drive shaft concentric with said wrist axis;
wherein said eccentric drive subassembly includes:
a first cam driver secured about said hand drive shaft, so as to rotate therewith, said first cam driver including an upper eccentric cylinder offset from said elbow axis and a lower eccentric cylinder offset from said elbow axis by the same magnitude but different direction from the offset of said upper eccentric cylinder;
a second cam driver, congruent in construction to said first cam driver but secured about said wrist drive shaft;
a first cam linkage including a circular first driver aperture and a circular second driver aperture, each said aperture having a diameter slightly larger than that of the respective eccentric cylinders such that said apertures slidably surround at least an annular portion of said respective upper eccentric cylinders of said first cam driver and said second cam driver, and a rigid linkage plate portion for delivering force from said first cam driver to said second cam driver;
and
a second cam linkage, congruent in construction to said first cam linkage but encompassing said respective lower eccentric cylinders of said first cam driver and said second cam driver.

7 more elements

Facts

Application

07/026,183Filed 16 Mar 1987

Granted

21 Mar 1989

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

B25J 9/042
Cylindrical coordinate type: comprising an articulated arm
B25J 9/105
Characterised by positioning means for manipulator elements: using eccentric means
B25J 9/109
Characterised by positioning means for manipulator elements: comprising mechanical programming means, e.g. cams
B25J 15/0616
With vacuum or magnetic holding means: with vacuum

Abstract

Claims12