Conveyors: power-driven – Conveyor system for moving a specific load as a separate unit – System includes an oscillating or reciprocating load...
Reexamination Certificate
2002-08-22
2004-03-09
Bidwell, James R. (Department: 3651)
Conveyors: power-driven
Conveyor system for moving a specific load as a separate unit
System includes an oscillating or reciprocating load...
C198S346300
Reexamination Certificate
active
06702099
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a work conveying system for a clean room and more particularly to a work conveying system which conveys a workpiece to various processing stations in a production line within a clean room for the production of, for example, semiconductor components, liquid crystal display panels, medical supplies, chemicals, and processed foods.
2. Description of the Prior Art
In manufacture of a semiconductor integrated circuit or a liquid crystal display panel, deposition of dust must be avoided. It is desirable that medical supplies, chemicals, and processed foods be produced in a sterile hygienic environment. Therefore, in a wide variety of fields, intra-clean room production lines are utilized.
The present applicant has previously invented a work conveying system (see Japanese Patent Laid Open No. 2000-243808), which system is provided with drive means able to arbitrarily move a work holding means in three dimensions in an upper ceiling space within a clean room. In this work conveying system, a pair of horizontal fixed guide rails are laid in parallel in the ceiling space and one or plural horizontal traveling guide rails are mounted between the paired fixed guide rails for travel along the fixed guide rails. Also, a travel body is mounted for travel along the traveling guide rail(s), and a horizontal moving means is provided by the combination of the fixed guide rails, the traveling guide rail(s) and the travel body. Further, the travel body is provided with a vertical moving means for raising and lowering the work holding means. Thus, three-dimensional movement/conveyance is provided by the combination of the vertical moving means and the horizontal moving means.
FIGS.
10
(A),
10
(B),
11
(A) and
11
(B) show such a vertical moving means
013
, in which FIG.
10
(A) is a front view showing a raised state of the vertical moving means, FIG.
10
(B) is a side view in vertical section, FIG.
11
(A) is a front view showing a lowered state thereof, and FIG.
11
(B) is a side view in vertical section. As shown in these figures, the vertical moving means
013
is an articulated arm having three arm elements
016
-
018
. With pivotal movements of a first start-end arm element
016
, a second arm element
017
, and a third (terminal-end) arm element
018
, a work holding means
011
fixed to the third (terminal-end) arm element
018
is moved up and down on a vertical line. The work holding means
011
delivers a workpiece (e.g., a hermetically sealed container) to each of various processing apparatuses. As shown in FIGS.
10
(B) and
11
(B), the articulated arm has the arm elements
016
-
018
stacked in multiple stages.
The pivotal movements of the arm elements
016
-
018
are respectively driven by a motor
021
a
disposed within a body
015
, a motor
021
b
disposed within the first start-end arm element
016
, and a motor
021
c
disposed within the second arm element
017
. Though not shown in detail, the interiors of the arm elements
016
-
018
and the interior of the body
015
are in communication and are under a negative pressure so that dust generated in those interiors is removed in one direction.
With the above-described work conveying system, an area for work conveyance is not required on the floor surface of the clean room and the interior of the clean room can be more effectively utilized. Therefore, for the same equipment, the space required in the clean room can be reduced and it is possible to reduce the equipment cost and operation cost of the clean room. Moreover, the location and orientation of apparatus such as processing chambers installed within the clean room are not restricted and it is possible to select an optimal arrangement. Also in the case of adding a new apparatus such as a processing chamber or in the case of changing the arrangement of items such as processing chambers, it is possible to freely select their arrangement and orientation. Thus, it is also possible to reduce the cost of changing arrangement of or increasing the number of items of apparatus such as processing chambers. Further, it is possible to move the work holding means
011
linearly from one position to another position, whereby the work efficiency in the clean room is improved.
However, in the above-described work conveying system, a torque load based on arm weight is imposed on the mounting portion for mounting to the horizontal moving means and deflection caused by extension of the articulated arm is significant. Further, in the articulated arm of this structure, the pivotal movement of the first start-end arm element
016
relative to the horizontal moving means is performed by operation of a motor
021
a
provided on the horizontal moving means (travel body
015
) side and thus this structure is difficult to seal. In addition, motors
021
a
-
021
c
are used as dedicated drive sources for pivotal movements of the first to third arm elements
016
-
018
, respectively, and such multiple drive sources are apt to generate dust.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above-mentioned problems of the conventional work conveying system and to provide a work conveying system which eliminates gravitational deflection induced upon extension of the articulated arm in the vertical moving means, permits the work holding means to deliver a workpiece to each processing apparatus without dislocation, permits smooth extension and contraction of the articulated arm, permits the vertical moving means to be folded compactly when conveying a workpiece horizontally, thereby minimizing the disturbance of air flow, and which is easily sealed.
It is another object of the present invention to provide a work conveying system which, in the case of workpieces in the form of wafers or reticles, can convey the wafers or reticles each individually and rapidly to a predetermined processing apparatus and can thereby improve the working efficiency.
For solving the foregoing problems, in one aspect of the present invention, there is provided a work conveying system comprising a work holding means for holding a workpiece, a horizontal moving means for moving the work holding means horizontally in an upper ceiling space within a clean room, and a vertical moving means provided in the horizontal moving means and formed as an articulated arm, the articulated arm being adapted to extend and contract, thereby causing the work holding means to move up and down, the workpiece thereby being conveyed to the plural items of apparatus while circulating among the processing stations within the clean room, wherein plural arm elements of the articulated arm are overlapped and connected together at alternating end portions, and the articulated arm is extended and contracted with pivotal movements of the arm elements.
With the above-described first aspect of the invention there is no fear of centroid deviation of the articulated arm and the weight balance of the entire arm is stable, with little gravitational deflection, even upon extension (descent of the vertical moving means). Consequently, it becomes possible for the work holding means to deliver a workpiece to each of various processing apparatuses without dislocation, the extension and contraction of the articulated arm being performed smoothly, and when conveying a work horizontally, the vertical moving means can be folded compactly to minimize the disturbance of air flow. Further, there is no torque based on the weight of the entire arm and the workpiece weight, thus permitting stable conveyance of a workpiece horizontally.
In a second aspect the present invention provides a work conveying system comprising work holding means for holding a workpiece, horizontal moving means for moving the work holding means horizontally and located in an upper ceiling space within a clean room, and an articulated arm, serving as vertical moving means and provided on the horizontal moving means. The articulated arm extends and contracts to thereby cause the work holding m
Iseri Takafumi
Matsumura Kazuyuki
Otaguro Tetsunori
Bidwell James R.
Hirata Corporation
Lorusso, Loud & Kelly
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