Turning – Lathe
Reexamination Certificate
2000-08-07
2003-04-29
Tsai, Henry W. H. (Department: 3722)
Turning
Lathe
C082S128000, C082S129000, C082S149000
Reexamination Certificate
active
06553875
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to machine tools and, more particularly, to a machine tool assembly that can be operated with the machine tool assembly in different orientations.
2. Background Art
Designers of machine tools attempt to achieve a number of different goals. First of all, accuracy is of utmost importance in the design of any machine tool. At the same time, it is desirable to make machine tools to have a relatively compact construction.
A conventional machine tool construction is shown in
FIGS. 1-3
herein at
10
. The machine tool
10
consists of a base
12
with an upper surface
14
supporting machine tool components, in this case a workpiece holder
16
and a machining unit
18
, for performing a machining operation on a workpiece
20
on the workpiece holder
16
.
In designing the base
12
forthe machine tool components
16
,
18
, there are a number of considerations. First of all, the height of the upper surface
14
above the subjacent surface
22
, as indicated by the double-headed arrow
24
, is generally selected to match the waist height for an operator
28
, as indicated by the double-headed arrow
26
. Consequently, the base
12
, by reason of this height requirement, has a substantial mass. Since the base
12
is commonly constructed from a heat conductive material, the larger the mass, the more heat retention there is during operations and the more the base becomes prone to thermally induced deformation. The potential deflection of spaced ends of the base
12
, due to heating, is shown schematically in
FIG. 3
, as indicated by the dotted lines
12
. Any base deformation potentially causes a misalignment of the cooperating workpiece holder
16
and machining unit
18
, which may detract from the accuracy of any machining operation.
This conventional type of machine tool
10
is normally constructed by building the components thereof in a pyramidal-type fashion for stability. That is, inherently the overall stability of the machine tool
10
is established and maintained by stacking components, as indicated by the arrows
30
, like building blocks of decreasing mass, from bottom to top. This construction is desired for stability in this type of system and is classified as an open loop system.
As seen in
FIG. 3
, an open loop system is one wherein the operating components and the base are not structurally contiguous. In
FIG. 3
, it can be seen that the machining unit
18
has a cantilevered working end
32
which operates on the workpiece
20
which is cantilever supported from the workpiece holder
16
. Thus, the structural loop, as indicated by the arrows
34
, is interrupted between the machining unit
18
and the workpiece holder
16
. Consequently, any deformation of the base
12
may cause a relative repositioning of the workpiece holder
16
and machining unit
18
so as to potentially detract from the accuracy of any machining operation. Similarly, any movement of the workpiece holder
16
and machining unit
18
relative to each other and the base
12
may have the same consequences.
SUMMARY OF THE INVENTION
In one form, the invention is directed to a machine tool assembly having a frame, a workpiece holder, and at least one machining unit that is operable to perform an operation on a workpiece in an operative position on the workpiece holder. The frame has first and second spaced end supports and at least one reinforcing element which extends between the first and second end supports so as to maintain the first and second end supports in a desired operative relationship. The workpiece holder and at least one machining unit each are connected to at least one of the first and second end supports and at least one reinforcing element so that the machining unit can be operated to perform an operation on a workpiece in an operative position on the workpiece holder.
In one form, the first and second end supports have the form of a disk-shaped element, with the at least one reinforcing element having the shape of a first elongate bar.
The elongate bar may extend through at least one of the first and second end supports.
The frame may further include a second elongate bar, with each of the first and second elongate bars having a length, with the lengths of the first and second elongate bars being substantially parallel.
The frame may further include a third elongate bar.
The frame may further include a third disk-shaped element which is connected to the first elongate bar.
The at least one reinforcing element may be in the form of a first elongate plate.
The frame may include a second elongate plate which connects to the first and second end supports.
The first elongate bar may include first and second joinable parts.
The first and second joinable parts may be extendable, one within the other.
In one form, the first joinable part has an annular inside surface and the second joinable part has an annular outside surface with the at least one reinforcing element including a wedge assembly with a first wedge element between the annular inside surface of the first joinable part and the annular outside surface of the second joinable part.
The wedge assembly may further include a second wedge element between the annular inside surface of the first joinable part and the annular outside surface of the second joinable part.
The first and second wedge elements may act directly against each other.
The second wedge element may be threadably engaged with the second joinable part.
The wedge assembly may further include a wedge repositioning element which can be directed into the first joinable part to reposition at least one of the first and second wedge elements.
In one form, the first joinable part has an end and the wedge repositioning element has a shoulder which is abuttable to the end of the first joinable part to limit movement of the wedge repositioning element into the first joinable part.
The first elongate bar may have a through passageway.
A temperature controlling fluid may be directed through the passageway of the first elongate bar.
In one form, the first elongate bar has a cross-sectional configuration taken transversely to its length which is substantially circular.
This cross-sectional configuration may be non-circular or polygonal.
In one form, the first and second end supports each include a disk-shaped element with a perimeter edge defining substantially a circular shape.
The perimeter edges of the end supports may define a square shape.
In one form, the perimeter edges have spaced projections which may be bridged by a support upon which the machine tool assembly is placed.
The shape of the peripheral edges of the first and second end supports may be substantially the same.
In one form, the first and second end supports and at least one reinforcing element cooperatively define a caged working space within which a machining operation may be performed by the at least one machining unit.
In one form, the first and second end supports have first and second facing surfaces which bound a working space and the at least one machining unit is mounted on the first facing surface.
In one form, the first end support has oppositely facing first and second surfaces on the first and second opposite sides of the first end support and the workpiece holder is on the first side of the first end support and the at least one machining unit is on the second side of the first end support.
The first end support may have an opening through which a workpiece held by the workpiece holder can be directed to be operated upon by the at least one machining unit.
In one form, the frame, workpiece holder, and at least one machining unit define a machine tool module that can be operated in any orientation.
In one form, the frame defines a passageway for guiding movement of a temperature controlling fluid.
In one form, the at least one reinforcing element has a first elongate hollow bar, the frame has a second elongate hollow bar extending between the first and second end supports, and a passageway for temperature controlling flu
Tsai Henry W. H.
Wood Phillips Katz Clark & Mortimer
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