Machine element or mechanism – Control lever and linkage systems – Multiple controlling elements for single controlled element
Reissue Patent
2000-08-28
2002-06-11
Bucci, David A. (Department: 3682)
Machine element or mechanism
Control lever and linkage systems
Multiple controlling elements for single controlled element
C414S744500, C414S935000, C414S941000
Reissue Patent
active
RE037731
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a two-armed transfer robot useful for semi-conductor manufacturing equipment, liquid crystal display processing equipment and the like. More particularly, the present invention relates to a two-armed transfer robot for transferring workpieces between processing chambers under a vacuum.
2. Description of the Related Art
In general, transfer robots are used for semi-conductor manufacturing equipment, liquid crystal display processing equipment and the like. The robot has at least one arm mechanism provided with a handling member. An object to be processed or workpiece such as a silicon wafer is placed on the handling member. The arm mechanism is capable of moving horizontally in a straight line as well as rotating in a horizontal plane. A plurality of processing chambers for performing various kinds of processing are arranged around a rotation axis of the robot. With the use of the transfer robot, the workpiece is suitably brought to and taken away from a selected one of the processing chambers.
For improving efficiency in the transferring operation, use has been made of the so-called two-armed transfer robot having two arm mechanisms. Each arm mechanism has a free end at which a handling member is mounted.
A conventional two-armed transfer robot is disclosed in Japanese Patent Application Laid-open No. 7(1995)-142552 for example.
Referring to
FIGS. 14-17
of the accompanying drawings, the prior art robot includes a stationary base frame
80
, an inner frame
81
and a first arm
82
. The inner frame is rotatable about a vertical axis O
1
, relative to the base frame
80
, while the first arm is rotatable about a first axis P
1
extending in parallel to the axis O
1
. The rotation of the inner frame
81
is actuated by a driving device fixed to the base frame, while the rotation of the first arm
82
is actuated by a driving device fixed to the inner frame
81
.
Reference numeral
83
indicates a second arm which is rotatable relative to the first arm
82
about a second axis Q
1
, extending in parallel to the first axis P
1
, while reference numeral
84
A indicates a handling member which is rotatable relative to the arm
83
about a third axis R
1
extending in parallel to the second axis Q
1
. Reference numeral
85
indicates a first rotation-transmitting member which is fixed to the inner frame
81
coaxially with the first axis P
1
, while reference numeral
86
indicates a second rotation-transmitting member which is fixed to the second arm
83
coaxially with the second axis Q
1
.
Reference numeral
87
indicates a third rotation-transmitting member fixed to the first arm
82
coaxially with the second axis Q
1
, while reference numeral
88
indicates a fourth rotation-transmitting member fixed to the handling member
84
coaxially with the third axis R
1
.
A first connecting member
89
is provided between the first rotation-transmitting member
85
and the second rotation-transmitting member
86
, while a second connecting member
90
is provided between the third rotation-transmitting member
87
and the fourth rotation-transmitting member
88
. The distance S between the first and second axes is equal to the distance between the third and fourth axes. The radius ratio of the first rotation-transmitting member
85
to the second rotation-transmitting member
86
is 2 to 1. The radius ratio of the fourth rotation-transmitting member
88
to the third rotation-transmitting member
87
is also 2 to 1.
Chain sprockets or pulleys may be used for the first to fourth rotation-transmitting members
85
-
88
. Correspondingly, the first and second connecting members
89
,
90
may be chains or timing belts.
The first arm mechanism
91
is made up of the above-mentioned elements
82
-
90
. A second arm mechanism
92
, which is symmetrical to the first arm mechanism with respect to the X—X line, is supported for rotation about the second axis P
2
extending in parallel to the axis O
1
.
Thus, the distance between the axis O
1
, and the first axis P
1
is equal to that between the axis O
1
and the second axis P
2
. The two-armed transfer robot is made up of the above elements
80
-
92
.
The operations of the first and the second arm mechanisms
91
,
92
are symmetrical with respect to the X—X line and substantially the same. Therefore, description will be made to the operation of the first arm mechanism
91
.
First, it is assumed that the inner frame
81
is kept stationary to the fixed base frame
80
, and that the first, second and third axes P
1
, Q
1
, R
1
are initially located on a common straight line, as shown in FIG.
16
. Starting from this state, the first arm
82
is rotated counterclockwise through an angle &thgr; about the first axis P
1
.
During the above operation, the first rotation-transmitting member
85
is stationary, while the second axis Q
1
is rotated counterclockwise through the angle &thgr; to be brought to the Q
11
position. As a result, a Y
1
-side portion of the first connecting member
89
is wound around the first rotation-transmitting member
85
, whereas a Y
2
-side portion is unwound from the first rotation-transmitting member
85
.
Thus, the first connecting member
89
is shifted in a direction shown by arrows a
1
and a
2
. As a result, the second rotation-transmitting member
86
is rotated clockwise about the second axis Q
1
.
As previously mentioned, the radius ratio of the first rotation-transmitting member
85
to the second rotation-transmitting member
86
is 2 to 1. Thus, when the first arm
82
is rotated counterclockwise about the first axis P
1
through the angle &thgr;, the second rotation-transmitting member
86
is rotated clockwise about the second axis Q
11
through an angle 2&thgr;.
At this time, since the second rotation-transmitting member
86
is fixed to the second arm
83
, the second rotation-transmitting member
86
and the second arm
83
are rotated clockwise about the second axis Q
1
through an angle
2
&thgr;.
If the second arm
83
is not moved relative to the first arm
82
, the third axis is brought to the R
11
position shown by broken lines when the first arm
82
is rotated counterclockwise about the first axis P
1
through an angle &thgr;, starting from the initial state where the first, the second and the third axes P
1
, Q
1
, R
1
are positioned on the same line. Actually, however, the second rotation-transmitting member
86
is rotated clockwise about the second axis Q
11
through an angle 2&thgr;. Therefore, the third axis R
11
is rotated clockwise about the second axis Q
11
through the angle 2&thgr;, and brought to the R
12
position.
As a result, after the first arm
82
is rotated counterclockwise about the first axis P
1
through an angle &thgr;, the third axis R
12
is still on the straight line extending through the first and the third axis P
1
and R
1
.
Further, when the second arm
83
is rotated clockwise about the second axis Q
11
through an angle 2&thgr; so that the third axis is brought to the R
12
position, a Y
2
-side portion of the second connecting member
90
is wound around the third rotation-transmitting member
87
, whereas a Y
1
-side portion is unwound from the third rotation-transmitting member
87
.
As a result, the second connecting member
90
is shifted in a direction b
1
-b
2
shown in FIG.
16
. Thus, the fourth rotation-transmitting member
88
is rotated counterclockwise about the third axis R
12
.
When the second arm
83
is rotated clockwise about the second axis Q
11
through an angle 2&thgr; as described above, the fourth rotation-transmitting member
88
is rotated counterclockwise about the third axis R
12
through an angle &thgr; since the radius ratio of the fourth rotation-transmitting member
88
to the third rotation-transmitting member
87
is 2 to 1. As a result, a point C
o
of the fourth rotation-transmitting member
88
is brought to a point C
1
on the straight line passing through the first and the third axes P
1
, R
12
.
Upon rotation of the first arm
82
abo
Ogawa Hironori
Yoda Hirokazu
Bucci David A.
Daihen Corporation
Joyce William C
Merchant & Gould P.C.
LandOfFree
Two-armed transfer robot does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Two-armed transfer robot, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-armed transfer robot will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2955794