Turning – Process of turning
Patent
1985-07-15
1986-03-11
Vlachos, Leonidas
Turning
Process of turning
82 25, 82 36B, B23B 1300, B23B 2912
Patent
active
045746664
DESCRIPTION:
BRIEF SUMMARY
Numerical control is increasingly widespread in machine-tool applications because, using a computer programmed for the functions of such a machine, the production of a given piece can be started at once. To that end it suffices to provide the computer with the data relating to the sequence of machining operations and the dimensions of the workpiece to be produced, and this procedure takes only a few minutes.
Numerical control therefore offers the advantage of eliminating set-up operations, which comprise plotting the cam graphs, grinding and finally mounting these cams, which is particularly tedious in the case of the "Swiss" type lathes (the so-called sliding headstock type), because in addition to controlling the tools, it also is necessary to control the simultaneous displacement of the workpiece along its axis while it is being machined.
These latter lathes are capable of high-precision machining and heretofore have been used only for the mass-production of identical pieces which warrant both the time needed to prepare the cams and the shutdown time required for cam assembly and start-up of all operations. Presently, thanks to numerical control these lathes can be used in an economical manner even to manufacture a single workpiece, for instance, a prototype.
Furthermore numerical control is more flexible than the use of cams in that it permits error correction in machining programs in just a few seconds or modifying, under the same conditions, one or more dimensions of the piece to be made, or the motion of one or several machine members.
To avail themselves of the many advantages of numerical control, the manufacturers of the "Swiss" type of automatic lathes have endeavored to control the various parts of their machines by limiting themselves to substituting for the cams heretofore in use stepping motors or hydraulic pistons controlled by the numerical-control pulse-generator.
However, the retention of the conventional arrangement of the basic members of these lathes has led to pell-mell designs wherein the kinematics providing the transmission of the required motions from lathe members controlled by electric pulses to the basic lathe parts is implemented in a manner not availing itself of the nature of these former members and of the possibilities due to their mode of control.
The known numerically controlled automatic lathes have an axially mobile spindle for both rotationally driving a bar of stock and axially displacing it toward the tool work area, radially fanned-out and slidable tools located roughly perpendicularly to the spindle axis, and stepping motors associated with the tools to control radial movement thereof, the stepping motors themselves being controlled by control pulses from a computer. In such known numerically controlled automatic lathes the tools under consideration, which as a rule are bits for shaping the outer surface of the workpieces by turning, and in case the pieces are produced from a bar of stock, in sectioning them off this bar, consist as in the cam-controlled lathes of long prismatic bars held in tool-holders mounted on slide means themselves fastened by a trunion to a vertical plate fixed to the lathe base. Besides the fact that such an arrangement of lathe tools is bulky, it comprises many cantilever situations obviously unlikely to ensure high stability of the cutting edges of these tools with respect to the lathe base and consequently with respect to the workpiece.
It is the object of the invention to create an improved numerically controlled automatic lathe wherein the stability of the radial tools is better ensured than in the known lathes, while simultaneously simplifying the design, facilitating the adjustments and reducing the bulk thereof.
This is accomplished by fixing the tools in cylindrical sliders guided by bores formed in a support mounted directly on the bed of the lathe. The motors also are mounted on this support and control movement of the corresponding slides by a direct and dual-effect kinematic linkage. This construction guaranties the stability
REFERENCES:
patent: 446448 (1891-02-01), Henley et al.
patent: 2376476 (1945-05-01), Chatelain
patent: 2634645 (1953-04-01), Jobert
patent: 3604293 (1971-09-01), Foll et al.
patent: 4202226 (1980-05-01), Becker et al.
patent: 4250779 (1981-02-01), Feller et al.
patent: 4366543 (1982-12-01), Feller et al.
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