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US 4,902,258 AGranted
Robotic assembly system
AssigneeInternational Business Machines Corporation
InventorsJohn Dunsmore, David C. Teale
Life of this patent
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AssigneeInternational Business Machines Corporation
InventorsJohn Dunsmore, David C. Teale
Estimating the term…
A robotic assembly system for the automatic assembly of a complex article such as a CRT display unit has a number of workstations positioned along an open conveyor system at each of which as assembly operation is performed by a conventional stand-alone robot. Each workstation is provided with a basic lift mechanism (36, 17, 21, 24, 28) which when operated lifts a pallet (4) supplied thereto from the relatively imprecise surface of the conveyor (1) into a predetermined horizontal plane above the conveyor where it is accurately located. A stand-alone robot, programmed to operate with reference to this constant datum position performs the assembly operation associated with that workstation. In order to assist the assembly operation, an air bearing table (17) is incorporated in the lift mechanism to provide the pallet, and any article carried by the pallet, with lateral compliance while held at the datum position. On completion of the assembly operation, the lift mechanism is retracted, lowering the pallet back onto the conveyor for transportation to the next workstation. The invention is particularly suited for assembly operations involving the handling of potentially hazardous components such as, for example, CRTs during the assembly of a display motor. A modification to the basic lift mechanism enables the assembly of a CRT into its surrounding bezel to be performed. The modification includes the addition of a further lift device (35, 38) which, when operated, lifts a platform (30) through an aperture (34) in the pallet into a second predetermined horizontal plane. To perform the assembly operation, a pallet (4) already supporting a part-cabinet (8) including its bezel surround (9) as a result of a previous assembly operation, is raised into the first datum position. The platform is then raised into the second datum position above the first. A stand-alone robot, programmed to operate with reference to the second datum places and releases a CRT face-plate down on the platform. The platform is then lowered back through the aperture in the pallet leaving the CRT supported in the bezel surround. The pallet is finally lowered onto the conveyor for transportation to the next workstation.
A robotic assembly system in which pallets, on each of which an article is to be assembled, are transported by a conveyor from one workstation to the next, at each of which an assembly operation is to be performed by a robot, characterized in that at each workstation means are provided for stopping and coarsely positioning a pallet supplied thereto, and each said workstation includes a linear lift mechanism operable to engage and lift a pallet coarsely positioned thereat from the conveyor, along an axis, into a precisely located vertical position, said lift mechanism including compliant means operable to provide said pallet with lateral compliance in all directions within a plane which is substantially normal to said axis while supported by said mechanism in said vertical position, the system further including means at the workstation to cause said lift mechanism to lift and support the pallet in said vertical position for a subsequent assembly operation performed by a robot, the pre-programmed operating characteristics of which have been determined with reference to said vertical position of the pallet, and upon completion of the assembly operation to lower the pallet onto the conveyor for transportation out of the workstation.
A method for the automatic assembly of a CRT display unit includes the steps of:
Dependencies are inferred from the claim text.