Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to machine tool beds and
uprights.
In the past, machine tool beds and uprights were
made of cast iron or steel, which are both heavy and ex-
pensive, or were made of welded flat frame members which,
though light and inexpensive with respect to castings, were
relatively weak. The principal object of this invention is
to provide a machine tool bed and upright which are
relatively light and inexpensive and are also relatively
strong.
The bed of a machine tool is made of structural
steel tubes which are connected together to form a unitary
structure. A pair of ways is attached to the tubes to
slidably receive an upright thereon.
In accordance with the invention there is provided
in a machine tool having a bed and having a member slidably
mounted on said bed for movement along a horizontal axis,
the improvement wherein said bed comprises a plurality of
structural steel tubes, all of said tubes being sub-
stantially rectangular in cross sectional shape and extend-
ing in a parallel relationship, at least one flat
longitudinal face of each of said tubes being in abutment
and connected with an adjacent tube; means connecting the
ends of all of said tubes together to form a unitary
structure; and a pair of ways attached to said tubes for
slidably supporting said member.
The invention is illustrated in a particular
and preferred embodiment by reference to the accompanying
drawings in which: ¦
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la -
Figure 1 is a side elevational view of a machinetool utilizing a preferred embodiment of the invention;
Fig. 2 i9 a front elevational view of the machine
tool of Fig. l;
Fig. 3 is a cross-sectional view taken on the
line 3-3 of Fig. 2,
Fig. 4 is a cross-sectional view taken on the
line 4-4 of Fig. 2;
Fig. 5 is a cross-3estional view taken on the
line 5-5 of Fig. 1, and
Fig. 6 is an exploded perspQctive view of the
~ed shown in Figs. 1 and 5.
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Referring to Figs. 1 and 2, one preferred embodiment
of the invention is utilized in combination with a machine
tool which includes a first bed 10, a irst pair of hori-
zontal ways 12 supported on bed 10, a worktable 14 slid-
ably mounted on ways 12 for movement along a horizontal Zaxis 13, a second bed 16, a second pair of horizontal ways
18 supported on bed 16 and an upright 20 slidably mounted
on ways 18 for movement along a horizontal X axis 19 per-
pendicular to the Z axis. A pair of vertical ways 22 is
supported on the front of upright 20 and slidably engages
a spindlehead 24 which is movable along a vertical Y axis
25 perpendicular to both X axis 19 and Z axis 13. A spin-
dle 26 is rotatably mounted on spindlehead 24 and is a-
dapted to rotate a tool tnot shown) to perform work on a
worXpiece (not shown) mounted on worktable 14.
This particular machine tool also has an automatic
tool changer 27 which includes a tool changer arm 28, a
tool changer carriage 30 and a tool changer drum 32. Au-
tomatic tool changer 27 acts to transfer toolholders 34
carrying tools 36 from tool changer drum 32 to spindle 26
and vice versa. However, it should be understood that
automatic tool changer 27 is not an essential feature of
the invention and that the machine tool could include a
different type of automatic tool changer or no automatic
tool changer.
Figs. 3, 4, 5 and 6 show the detailed structure of beds
10 and 16 and upright 20. Referring to FigsO 5 and 6, bed
10 includes four structural steel tubes 40, 42, 44 and 46
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which are all substantially rectangular in cross-sectional
shape. Structural steel tubes 40 to 46 are all the same
length and are welded to two steel end plates 48 and 50
and to each other to form a unitary bed structure. (In
Fig. 6, tubes 40 to 46 are shown exploded laterally and
hence appear to be wider than end plates 48 and 50. How-
ever, end plates 48 and 50 extend the full width of tubes
40 to ~6 as shown in Fig. 5). A plurality of flat steel
foot plates 52 and braces 54 are welded to the bottom of
the outer tubes 40 and 46 at spaced intervals to provide
support for the structure. After the assembly is welded to-
gether, tapped holes (not shown) are formed in foot plates
52 to interact with conventional leveling screws (not shown)
on the floor where the machine is to be installed.
A pair of flat steel strips 56 and 58 are welded to the
top of tubes 40 and 46 to serve as a base for ways 12. Pre-
cision grooves 60 and 62 are milled in strips 56 and 58 af-
ter the bed is assembled to hold ways 12 in a precise posi-
tion with respect to foot plates 52. The bed is preferably
heat treated before machining to relieve stress due to un-
equal temperatures generated during the welding process.
The use of structural steel tubes for the basic build-
ing blocks of the bed has several advantages. In the first
place, the tubes are both relatively light and relatively
strong~ In addition, they are readily available in a large
variety of sizes and shapes since they are widely used as
structural members in building construction and crane manu-
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facturing. Also, the tubes are relatively inexpensive dueto their relatively large scale use. Finally, when the
tubes are laid parallel to each other, their rounded corn-
ers form a natural welding seam which eliminates the neces-
sity for scarfing.
As can be seen in Fig. 5, the central tubes 42 and 44
are shorter in height than the exterior tubes 40 and 46.
This is done to provide a recess in the bed to accommodate
the ball screw mechanism and other portions of the machine
tool that project beneath ways 12.
Fig. 4 is a cross-section taken on the line 4-4 of Fig.
2 and shows the construction of bed 16 which is similar to
bed 10. The basic building blocks of bed 16 are rectangular
structural steel tubes 64, 66, 68, 70 and 72. Foot plates 74
and braces 76 are welded to the hottom of the exterior tubes
64 and 72 and end plates 78 are welded to both ends of all
of the tubes 64 to 72. Steel strips 80 and 82 are welded to
the top of exterior tubes 64 and 72 to serve as bases for
ways 18 and precision grooves 84 and 86 are milled in strips
80 and 82 to receive ways 18.
Fig. 3 is a cross-sectional view taken on the line 3-3
of Fig. 2 showing the construction of upright 20. The basic
building blocks of upright 20 are rectangular structural
steel tubes 88, 90, 92, 94, 96 and 98 which are arranged in
two parallel rows and are welded on their bottom to a base
plate 100 and are welded together at adjacent edges to form
two upstanding structural sides. A sloping top plate 101
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(Fig. 1) is welded across the top of tubes 88, 90, 94 and 96
to serve as a base for supporting automatic tool changer 27.
A flat top plate 102 (Fig. 1) is welded across the top of
tubes 92 and 98 to serve as a base for supporting tool chan-
ger carriage 30. A pair of steel strips 103 and 104 (Fig.
3) are welded to the front of tubes 92 and 98 and have pre-
cision milled grooves 106 and 108 for receiving ways 22
which slidably support spindlehead 24.
Although the illustrative embodiment of the invention
has been described in considerable detail for the purpose o~
fully disclosing a practical operative structure incorpora- `
ting the invention, it is to be understood that the particu-
lar apparatus shown and described is intended to be illustra-
tive only and that the various novel features of the inven-
tion may be incorporated in other structural forms withoutdeparting from the spirit and scope of the invention as de-
fined in the subjoined claims.
