Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02497250 2005-02-14
RAIL AND SADDLE FOR A GANTRY ROBOT AND A GANTRY ROBOT INCLUDING
THE SAME
FIELD OF THE INVENTION
The present invention relates to the field of automation, and more
particularly, to rail
and saddle assemblies for use with robots in gantry robots.
BACKGROUND OF THE INVENTION
Gantry robots are well-known. Such robots include a rail raised on standards,
a saddle
mounted to the rail for movement therealong, and a robot mounted to the saddle
for
movement therewith. In this arrangement, it is known to use a robot of the
type
generally known as a "6-axis robot", although in practise, one or more of the
axes of
motion may not be available.
Many combinations of rail and saddle are known in the prior art, and those in
the field of
automation systems integration select therefrom a combination suitable for the
particular task to be carried out by the robot. Some rail/saddle combinations,
for
example, are only suitable for supporting underslung robots, whereas others
are
suitable for use with side-mounted robots, and yet others are suitable for use
only with
top-mounted robots. This need, to pick and choose a raillsaddle combination,
depending upon the robot position, adds complexity and cost to automation
systems
integration, and the lack of standardization adds to procurement and
maintenance
costs.
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SUMMARY OF THE INVENTION
A rail for use in a gantry robot forms one aspect of the invention. The rail
comprises a
main body member having four plate-like portions connected to one another to
form a
square tube having four longitudinal edges defined by the intersections of the
connected plate-like portions. The rail preferably further comprises
a pair of elongate linear guide members disposed on opposite sides of a
respective one
of the plate-like portions, each guide member being connected to one of the
plate-like
portions contiguous with said respective one of the plate-like portions.
A saddle for use with the rail forms another aspect of the invention. The
saddle
comprises a first rail-engaging portion and a second rail-engaging portion.
The first and second rail-engaging portions are mounted, in use, each to a
respective
guide member, to permit movement of the saddle along the rail and to constrain
movement of the saddle otherwise.
A rail and saddle assembly forms another aspect of the invention. The rail and
saddle
assembly is for use with a robot in a gantry robot and comprises a rail and a
saddle.
The rail has a first axis and includes a first elongate saddle-engaging
portion and a
second elongate saddle-engaging portion, the first saddle-engaging portion and
the
second saddle-engaging portion being arranged parallel to the first axis and
spaced-
from one another in a direction transverse to the first axis, said direction
defining a
second axis. The rail is positioned, in use, such that the first axis is
orientated
substantially horizontally and the first saddle-engaging portion and the
second saddle-
engaging portion are spaced from one another both horizontally and vertically.
The
saddle is for receiving said robot in use, and includes a first rail-engaging
portion and a
second rail-engaging portion. The first rail-engaging portion and the second
rail-
engaging portion are mounted, respectively, to the first saddle-engaging
portion and the
second saddle-engaging portion to, in use, permit movement of the saddle and
said
robot along the rail, parallel to the first axis, and to constrain movement of
the saddle
otherwise.
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A gantry robot forms another aspect of the invention. The gantry robot
comprises a rail,
standards, a saddle and a robot. The rail has a first axis and includes a
first elongate
saddle-engaging portion and a second elongate saddle-engaging portion, the
first
saddle-engaging portion and the second saddle-engaging portion being arranged
parallel to the first axis and spaced-from one another in a direction
transverse to the first
axis, said direction defining a second axis. The standards support the rail
such that the
first axis is orientated substantially horizontally and the first saddle-
engaging portion and
the second saddle-engaging portion are spaced from one another both
horizontally and
vertically. The saddle includes a first rail-engaging portion and a second
rail-engaging
portion, the first rail-engaging portion and the second rail-engaging portion
being
mounted, respectively, to the first saddle-engaging portion and the second
saddle-
engaging portion to permit movement of the saddle along the rail, parallel to
the first
axis, and to constrain movement of the saddle otherwise. The robot
is mounted to the saddle for movement therewith along the rail.
Advantages, features and characteristics of the present invention, as well as
methods of
operation and functions of the related elements of the structure, and the
combination of
parts and economies of manufacture, will become more apparent upon
consideration of
the following detailed description and the appended claims with reference to
the
accompanying drawings, the tatter of which is briefly described hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a perspective view of a gantry robot, showing a preferred
embodiment of a
rail and saddle assembly according to the invention in a first mode of use.
FIGURE 2 is an end elevational view of the structure of FIGURE 1.
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FIGURE 3 is a perspective view of a duplex gantry robot, showing a second mode
of
use of a rail and saddle assembly constructed according to the preferred
embodiment
of the invention.
FIGURE 4 is an end elevational view of the structure of FIGURE 3, with one of
the pair
of robots not visible, for clarity.
FIGURE 5 is a view similar to FIGURE 4, with the other of the pair of robots
not visible,
for clarity.
FIGURE 6 is a perspective view of a main body portion of a saddle of the rail
and
saddle assembly of FIGURE 1.
FIGURE 7 is a side elevational view of the structure of FIGURE 6.
FIGURE 8 is a top plan view of the structure of FIGURE 6.
FIGURE 9 is a front elevational view of the structure of FIGURE 6.
FIGURE 10 is a cross-sectional view of the structure of FIGURE 6, along line
10-10 of
FIGURE 9.
FIGURE 11 is a perspective view of the rail of FIGURE 3 in isolation, with
interior
components shown in phantom outline.
FIGURE 12 is an enlarged view of the interior components shown in encircled
area 12
in FIGURE 11.
FIGURE 13 is a view of the structure of FIGURE 13, from a vantage opposite to
that of
FIGURE 12.
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DETAILED DESCRIPTION
With general reference to FIGURES 1-5, a rail and saddle assembly 20,22
constructed
according to a preferred embodiment of the invention is illustrated in use.
The rail and saddle assembly 20,22 includes a rail 20 and a saddle 22, as
identified in
FIGURE 1.
The rail 20 has a first axis A-A and includes a main body 24 and first 26 and
second 28
elongate saddle-engaging portions or guide members. The main body 24 has four
plate-like portions 30,32,34,36 connected to one another to form a square
tube. The
tube 30,32,34,36 defines the first axis A-A, and has four longitudinal edges
38,40,42,44
defined by the intersections of the connected plate-like portions 30,32,34,36.
The first
26 and second 28 saddle-engaging portions are arranged parallel to the first
axis A-A
and are connected to the tube 30,32,34,36 on opposite sides of a respective
one 30 of
the plate-like portions, each saddle-engaging portion 26,28 being connected to
one of
the two 32,34 plate-like portions contiguous with said respective one 30 of
the plate-like
portions. The first 26 and second 28 saddle-engaging portions are thereby
spaced-from
one another in a direction transverse to the first axis, said direction
defining a second
axis B-B, shown in FIGURE 2. Each saddle-engaging portion 26,28 is disposed
adjacent the longitudinal edge 38,40 defined by the intersection of the plate-
like portion
to which it is connected 32,34 and the respective one 30 of the plate-like
portions.
The saddle 22 has a main body 45 which defines a number of mounting surfaces
46, for
receiving a robot, and includes a first rail-engaging portion 48 and a second
rail-
engaging portion 50,50, respectively bolted to the main body 45. The first
rail-engaging
portion 48, in combination with the first saddle-engaging portion 26, forms a
linear slide
bearing, with the first rail-engaging portion 48 defining a slideway of said
bearing and
the first saddle-engaging portion 26 defining a slide of said bearing. Thus,
the first rail-
engaging portion 48 is mounted to the first saddle-engaging portion 26 in a
manner
which constrains movement of the first rail-engaging portion 48 relative to
the first
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saddle-engaging portion 26 in the direction of the second axis B-B, more
specifically,
which constrains movement of the first rail-engaging portion 48 relative to
the first
saddle-engaging portion 26 otherwise than along the rail 20, parallel to the
first axis A-
A. The second rail engaging portion 50,50 is mounted to the second saddle-
engaging
portion 28 in a manner which constrains movement of the second rail-engaging
portion
50,50 relative to the second saddle-engaging portion 28 in a direction
substantially
normal to the first axis A-A and to the second axis B-B, said direction
defining a third
axis C-C, shown in FIGURE 2. In the preferred embodiment illustrated, the
second rail-
engaging portion 50,50 in combination with the second saddle-engaging portion
28,
forms a roller guideway to provide such functionality, with the second saddle-
engaging
portion 28 defining a raceway of said roller guideway and the second rail-
engaging
portion 50,50 comprising two pairs of cam-followers or rollers 50. The pairs
of cam-
followers are spaced apart from one another along the raceway 28, and the cam-
followers 50 of each pair are rotatably mounted to the saddle main body 45,
spaced-
apart from one another on opposed sides of the raceway 28 and adapted for
rolling
movement therealong. The coaction of the linear bearing 48,26 and the roller
guideway
50,50,28 permits movement of the saddle 22 along the rail 20, parallel to the
first axis
A-A, and constrains movement of the saddle 22 otherwise.
In the Figures, the rail and saddle assembly 20,22 is shown in two distinct
modes of use
in gantry cranes 52,54. As neither the robots 58,60,62 nor the mechanisms by
which
the saddles 22 are driven form part of the present invention, and as the
method of
construction of such elements is readily understood by persons of ordinary
skill in the
art, a detailed description thereof is omitted herein.
In the gantry crane 52 of Figures 1-2, the rail 20 is supported by a pair of
standards 56
such the first axis A-A is orientated substantially horizontally and the
respective one 30
of the plate-like portions is disposed at an angle of 45° to
horizontal, thereby to space
the first saddle-engaging portion 26 and the second saddle-engaging portion 28
from
one another both horizontally and vertically, with the longitudinal edge 40 to
which the
second saddle-engaging portion 28 is adjacent disposed at the top of the rail
20.
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In the gantry crane 54 of Figures 3-5, the first axis A-A is again oriented
horizontally,
and the respective 30 one of the plate-like portions is again disposed at an
angle of 45°
to horizontal, to space the first saddle-engaging portion 26 and the second
saddle-
engaging portion 28 from one another both horizontally and vertically, but in
this use,
the rail 20 is supported by the standards 56 such that the longitudinal edge
38 to which
the first saddle-engaging portion 26 is adjacent is disposed at the bottom of
the rail 20.
The importance of such distinct orientations is as follows: the orientation of
Figures 1, 2
permits a robot to be top-mounted to the saddle 22, as evidenced by the
position of
robot 58 in Figures 1,2, whereas the orientation of Figures 3-5 permit a robot
to be side-
mounted or underslung to the saddle, as evidenced by robots 60,62 in Figures 3-
5.
Thus, the present invention permits the use of a common rail and saddle 20,22
combination to provide for gantry cranes bearing top-mounted, side-mounted and
underslung robots, with attendant advantage in terms of decreased costs for
design,
procurement and maintenance, as discussed above.
While but a single embodiment of the present invention has been herein shown
and
described, in two modes of use, it will be understood that various changes can
be made
without departing from the spirit or scope of the invention. For example,
whereas the
second rail-engaging portion of the preferred embodiment comprises two pairs
of cam-
followers, other arrangements, such as an arrangement using three pairs of cam
followers, could be employed. Similarly, five cam-followers could be
ernployed, with
three disposed on one side of the guideway, and two disposed on the other. Yet
further arrangements of cam followers could also be employed. As well, a
linear
bearing could be substituted for the roller guideway. Variations could, for
example, also
be made to the rail. Whereas a square tube is shown, a tube having a cross-
section in
the shape of a rhombus could conceivably be utilized. In view of these
potential
variations, it should be understood that the invention is to be limited only
by the claims
appended hereto, purposively construed.
