Claims
- 1. Method of straight-line drawing for reducing the cross section of round material, tubing, solid and hollow profiles in at least two drawing stages, which comprises feeding material with a leading end to a first drawing machine, drawing the material through the first drawing machine in a first drawing stage, feeding the material with the leading end in a straight line downstream of the first drawing machine, subsequently feeding the material with the leading end to at least one second drawing machine having a linearly movable intermittently operable drawing carriage operating at a discontinuous speed at the beginning of the second drawing stage while said first drawing machine is already operating continuously, being disposed downstream of the straight line, deflecting the material from the straight line upstream of the second drawing machine as soon as the leading end of the material has reached the second drawing machine, and varying the length of the deflected material for equalizing differences in feeding speed between said first and second machine.
- 2. Method according to claim 1, including additional drawing machines and additional guiding and deflecting means, comprising the step of: interconnecting said additional drawing machines.
- 3. Method for equalizing differences in drawing speed between a first material drawing machine operating in tandem with a second drawing machine disposed downstream from the first drawing machine, including a straight V-shaped material-guiding channel disposed between said first and second drawing machine having an interruption therein for admitting drawn material to a region of deflected material, disposed between said first and second machine, the method comprising the steps of: drawing the material through the first machine, guiding the drawn material in said channel from the point of material exit of the first machine via said interruption to the point of material entry of the second machine; deflecting the drawn material from said interruption to said region of deflected material in a direction and transverse to and away from said guiding channel; varying the length of the deflected material in response to said differences in drawing speed; drawing the material through the second machine; and moving said channel for ending said straight travel direction before deforming the material.
- 4. Method according to claim 3, which comprises: pivoting said V-shaped channel about an axis parallel therewith; radially moving said deflected material being drawn by means of a deformation device which includes a deflection slider.
- 5. Method according to claim 4, which comprises: moving said deflection slider by means of a piston-cylinder unit operated by a flowing medium.
- 6. Method according to claim 4, which comprises: placing at least two abutments for restraining the material being drawn, in the vicinity of said machine exit and entry.
- 7. Method for reducing the cross section of round material, tubing, solid and hollow profiles by line drawing in at least two stages, including a first drawing machine, at least one second drawing machine operating at a discontinuous speed at the beginning of the drawing, while said first drawing machine is already operating continuously, disposed downstream of said first drawing machine along a given travel direction of material to be drawn, at least the second drawing machine having a second drawing die for straight drawing, and means for interconnecting the drawing machines and means for interconnecting the drawing machines and means for deflecting the material to be drawn from the given straight travel direction, and a guiding device being a circular guide, the method comprising the steps of: interconnecting said drawing machines; guiding the material to be drawn to the drawing die of the second machine; deflecting the material to be drawn by the second machine from the straight travel direction; drawing said material through a first drawing machine and guiding the drawn material from a tangential emission from said first drawing machine through a circular-arcuate deflection; subsequently feeding the drawn material as a tangential insertion into said second drawing machine; and absorbing the differences in feeding speed between said first and second machine by means of radial motion of the center of said circular-arcuate deflection while said first drawing machine operates continuously and said second drawing machine operates at a discontinuous speed so as to draw the material leading end through said second die.
- 8. Method according to claim 7, wherein said guiding device includes a cross bar, a central support, a crossbar support on said central support which is pivotable about a vertical axis, said crossbar having a free end movable through a given operating range,and a gripping device disposed on said free end of said crossbar, the method comprising the steps of: accepting and transferring at a discontinuous speed the material to be drawn between said first and second drawing machines, said first drawing machine having an outlet and said second drawing machine having an inlet within said given operating range.
- 9. Method according to claim 8, wherein said drawing machines draw the material to be drawn in parallel operating directions,comprising the steps of: deflecting the material to be drawn by said guiding device through substantially 180.degree. of arc.
- 10. Method according to claim 8, comprising the steps of: driving said crossbar by means of a rotational drive.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 84112638.6 |
Oct 1984 |
EPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 788,782, filed Oct. 18, 1985, now abandoned.
The invention relates to a method for the straight-line drawing of round material and tubing as well as solid and hollow profiles for reducing the cross section in at least two drawing passes, wherein at least the second drawing stage is carried out in a drawing apparatus with a drawing carriage which operates intermittently and moves linearly, as well as to an apparatus for carrying out the method.
German Patent DE-PS No. 31 20 820 discloses carriage drawing machines for carrying out the above-mentioned method, which have found acceptance in practical use. Such machines operate in one stage and are capable of achieving a given reduction of the cross section in one drawing stage, depending on the ductility of the material to be drawn. In such a device the drawing carriages move back and fourth in opposite direction. At the beginning of the drawing operation, i.e., during the insertion process, insertion clamping jaws of a drawing carriage are closed exactly at the forward dead center of the first drawing carriage. The material which is ready for drawing is therefore drawn-in without jerking motions during the subsequent forward stroke of the first drawing carriage. The drawing-in jaws are released from the material to be drawn, which is now pulled in, at the end of this pulling-in stroke executed by the first drawing carriage, but not later than the start of the backward stroke of this drawing carriage. This pulling-in process is repeated several times. During this process, the material to be drawn is intermittently pulled-in with the corresponding linear motion of the drawing carriage, by equivalent and alternating closing and opening of the clamping jaws. During this pulling-in process, the material to be drawn is therefore pulled in by the first drawing carriage with individual interruped strokes until the beginning of the material to be drawn is downstream of the second drawing carriage. Then, the material to be drawn can be taken over by the second drawing carriage and the material to be drawn in advanced without jerking through appropriate control of both drawing carriages, resulting in a suitable simultaneous motion.
At the output of such a conventional drawing machine, the material to be drawn is wound on a drum with a radius that is suitable for the material to be drawn. After the material is completely wound onto the drum, it is further transported as a total package of material to the next drawing machine, where the already described and conventional drawing operation is repeated for the next reduction of the cross section, after threading-in. Basically, it would be desirable to make do without this intermediate winding on the drum of the material to be drawn or at least with as few intermediate winding operations as possible for the material to be drawn,and to pass on the material to be drawn directly from one drawing machine to the next. However, this is not possible with such straight-line drawing machines because, as just described, the drawing machine operates intermittently during the pulling-in operation and therefore forces hesitations of the material to be drawn, while the preceding drawing machine is in the middle of its operation, which therefore forces a continuous transport for the material. Added to this is the additional fact that both drawing machines which must be disposed in tandem, do not operate with exactly the same flow velocity of the mass of the material to be drawn, so that for this reason as well, it does not seem possible to couple straight-line drawing machines in tandem. Thus, intermediate winding operations on drums which interrupt the drawing process proper, are necessary if such drawing machines are used.
It is accordingly an object of the invention to provide a method and apparatus for straight-line drawing of round material and tubing as well as solid and hollow profiles which overcomes the hereafore-mentioned disadvantages of the heretofore-known methods and devices of this general type, and with which it becomes possible to connect straight-line drawing machines in tandem and to avoid the intermediate winding-up operations which have been necessary heretofore.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method of straight-line drawing for reducing the cross section of round material, tubing, solid and hollow profiles in at least two drawing stages or passes, wherein at least the second stage is carried out in a drawing machine, which comprises feeding material to be drawn with a leading end to a first drawing machine for a first drawing stage, feeding the material to be drawn with the leading end in a straight line downstream of the first drawing machine, feeding the material to be drawn with the leading end to at least one second drawing machine with a linearly movable and intermittently operable drawing carriage not in the first drawing machine downstream of the straight line for at least one second drawing stage, and deflecting the material to be drawn from the straight line upstream of the second drawing machine as soon as the leading end of the material to be drawn has reached the second drawing machine. This deflection from a straight line of the material to be drawn provides a buffer region for the motion of the material to be drawn so that the preceding drawing machine which operates in a continuous drawing process, can transport the material to be drawn into this generated arc in an undisturbed manner, while the subsequent drawing machine can take over the arriving material to be drawn in intermittent operation during the start of the drawing. Any material which is supplied too fast be the preceding drawing machine simply flows into the deflected part due to the deflection of the material to be drawn and enlarges this arc as much as necessary. This surprisingly simple measure for the first time permits the connection of straight-line drawing machines directly in tandem, without performing an intermediate drum wind-up of the material to be drawn and yet allowing them to work simultaneously. The material to be drawn remains in continuous flow and the drawing process need not be interrupted to carry out winding operations and transport operations.
With the objects of the invention in view there is also provided an apparatus for reducing the cross section of round material, tubing, solid and hollow profiles by straight-line drawing in at least two stages, comprising a first drawing machine, at least one second drawing machine disposed downstream of said first drawing machine along a given straight travel and working direction of material to be drawn, at least said second drawing machine having a drawing die for straight drawing, and guiding means interconnecting said drawing machines for guiding the material to be drawn to the drawing die of said second drawing machine and for deflecting the material to be drawn from said given straight travel direction. In this way, a drawing device adjacent a preceding drawing device can be connected directly to the preceding drawing device by the interposition of the guiding means, so that the material to be drawn can be passed on with the guiding means from one machine to the next, while providing for the necessary deflection of the material from the straight flow direction in the guiding means, by developing the necessary arc for buffering the material to be drawn. Once a deflection from the straight flow direction is generated, an enlargement of the generated part is carried out automatically. Furthermore, it is only necessary to consider one enlargement, because the material to be drawn is ejected during the intermittent operation of the second drawing device faster than it can be taken over by the second drawing device.
In accordance with another feature of the invention of the instant application, the guiding and deflecting means include a guiding device and a deformation device, at least the deformation device being movably guided for deforming the material to be drawn. In this case,the guiding device carries out the straight-line guidance, while the deformation device provides for the deflection from the straight travel direction. In this way,the functions "guidance" and "deflection" can advantageously be separated. The straight-line guidance is maintained as long as possible and the, if necessary,the deformation is initiated by the independent deformation device.
In accordance with a further feature of the invention of the instant application, the first drawing machine has an outlet, the second drawing machine has an inlet, the guiding device is a V-shaped channel connected between the outlet of the first drawing machine and the inlet of the second drawing machine for guiding the material to be drawn in the given straight travel direction, the channel has at least one interruption formed therein along the length thereof, and the deformation device is movable transversely to the given straight travel direction through the interruption. The V-shaped guiding channel is a particularly simple guiding device with a sufficiently reliable operation. The channel can be interrupted in its lengthwise course without difficulty or loss of its function, so that in the region, a deformation device which can be moved through this region, can be provided for deflecting the material to be drawn from straight travel direction. It is particularly advantageous in this case if this deformation device is provided approximately in the middle of the distance between the two drawing machines. In this way,the force for the deformation which must be supplied to the material to be drawn by the deformation device can be kept small and a uniform deflection on both sides is achieved in the travel direction.
In accordance with an additional feature of the invention of the instant application there is provided, means for moving the V-shaped channel for ending the straight travel direction before deforming the material to be drawn. It is possible through the use of these simple means to choose the radial plane in which the deformation is to be made, independently of the angular position of the V-shaped channel. Then, the radial deformation plane need not of necessity be located in such a way that the material to be drawn is lifted from the V-shaped channel by the deformation process, but the V-shaped channel can rather be movable so that is gives way to the material to be drawn that is being deformed.
In accordance with an added feature of the invention of the instant application there is provided, means for lowering the V-shaped channel. This is a direction of movement of the channel which can be provided simply.
In accordance with still another feature of the invention of the instant application there is provided, means for pivoting the V-shaped channel about an axis parallel to the length thereof. This possible motion can also be provided simply and permits the channel to give way to the desired direction of deformation of the material to be drawn.
In accordance with still a further feature of the invention of the instant application, the deformation device is a deflection slider being radially movable against the material to be drawn. Such a deflection slider can also be of simple construction, can be moved simply and can be guided radially toward the material to be drawn in a force-locking manner and therefore under continuous desired pretension. A force-locking connection is one in which two elements are locked together by external force, as opposed to a form-locking connection which is accomplished by virtue of the shape of the parts themselves. In this manner, a reliable defection of the material to be drawn is brought about because the deflection slider only rests against the material to be drawn in a force-locking manner, it is possible at the same time to use the deflection slider to follow enlargements as well as reduction of the deflection arc of the material to be drawn without difficulty.
In accordance with still an additional feature of the invention of the instant application, the deflection slider includes an actuating device, a carrier connected to the acting device, and at least one contact element disposed on the carrier for contacting the material to be drawn. This is also a particularly simple construction and with it it is possible to separate the motion and the elements exerting the force from the elements which come directly into contact with the material to be drawn, so that the contact elements can be adapted to the particular requirements of the respective material to be drawn without the need to simultaneously change all other subassemblies or components.
In accordance with still an added feature of the invention of the instant application, at least one contact element is a body being rotationally symmetrical and rotatable on the carrier about at least one axis,the contact element being perpendicular to a tangent at the contact point between the material to be drawn and the contact element. This may involve one or more rollers or wheels, so that on one hand, the bending radius of the material to be drawn can be influenced in a simple manner, and on the other hand, the axial motion is not impeded by unnecessarily great friction. In addition, detrimental influences on the surface fibers of the material to be drawn can be avoided by the reduction of the axial friction.
In accordance with again another feature of the invention of the instant application, the actuating device is a piston-cylinder unit operated by a flowing medium. This is the simplest means for achieving or obtaining the force-locking contact of the part which cause the deflection of the material to be drawn from the straight line.
In accordance with again a further feature of the invention of the instant application, the first drawing machine has an outlet, the second drawing machine has an inlet, and the guiding device includes abutments for restraining the material to be drawn in the vicinity of the outlet and the inlet. In this way, the corresponding guiding elements at the machines which are disposed in the vicinity of the output and the input are relieved of load and a gentle transition arc to the deflection arc can be provided which relieves the load of the material to be drawn itself.
In accordance with again an additional feature of the invention of the instant application, the guiding device being a circular guide guiding the material to be drawn from a tangential emission from the first drawing machine, through a circular-arcuate deflection, and to a tangential insertion into the second drawing machine. With this device it is possible to place machines that follow each other, parallel to each other, so that adaptation to the physical conditions available is possible in an advantageous manner. This is particularly important if the deflection is made along a circular track through about 180.degree.. In multistage drawing processes it is also possible to then place a machine group of several drawing machines initially in tandem and then to place further machines in parallel through a 180.degree. deflection. The deflection along a circular track through about 180.degree. is a particularly advantageous type of buffering, because in such a case almost any velocity differences between the two machines can be intercepted merely by moving the arc of 180.degree. as a whole further from or closer to the two machines mounted parallel to each other. The arc itself can remain unchanged in this case.
In accordance with again an added feature of the invention of the instant application,the guiding device includes a central support, a crossbar support on the central support and pivotable about a vertical axis, the crossbar having a free end movable through a given operating range, and a gripping device disposed on the free end of the crossbar for accepting and transferring the material to be drawn between the first and second drawing machines, the first drawing machine having an outlet and the second drawing machine having an inlet within the given operating range. In this manner, it is possible to generate the desired deflection with relatively simple means and to thereby create the desired deflection and thus, the required buffer zone. It is possible not only to simultaneously couple to drawing machines in series, but also to place them parallel to each other.
In accordance with yet another feature of the invention of the instant application, the drawing machines draw the material to be drawn in parallel operating directions, and the guiding device deflects the material to be drawn through substantially 180.degree..
In accordance with yet a further feature of the invention of the instant application there is provided, a drive rotationally driving the crossbar. For material to be drawn of larger cross section, this is not required. The crossbar itself which is centrally supported and could be constructed, for instance, as a wheel, can be driven by the working motion of the material to be drawn. In the case of material to be drawn having a smaller cross section, this leads to difficulties because the material to be drawn then buckles at undersirable points. The drive of the crossbar, which must rotate the crossbar in synchronism with the velocity of the arriving material to be drawn, therefore ensures that the buckling at undesirable points of the smaller cross section material to be drawn, is inhibited.
In accordance with a concomitant feature of the invention of the instant application there is provided, additional drawing machines and additional guiding and deflecting means interconnecting the drawing machines. In this manner it is possible to subdivide a drawing operation into as many stages as desired and to nevertheless establish an uninterrupted working process by interlinking all of the drawing machines with each other. An interruption of the drawing process is therefore no longer necessary.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in method and apparatus for straight-line drawing of round material and tubing as well as solid and hollow profiles, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:
FIG. 1 is a diagrammatic perspective view of a coupling of two drawing machines with an interposed guiding device;
FIG. 2 is a schematic circuit diagram and a fragmentary cross-sectional view taken along the line A-A in FIG. 1 in the . direction of the arrows;
FIG. 3 is a top-plan view of a system according to FIG. 1, but with an altered guiding device;
FIG. 4 is a top-plan view of two drawing machines disposed in parallel with a guiding device for guiding the material to be drawn in a circular arc guide;
FIG. 5 is a view as seen in the direction of the arrow B according to FIG. 4;
FIG. 6 is a view similar to FIG. 3 but with an interlinkage of more than two drawing machines;
FIG. 7 is a diagrammatic view of a system with two groups of drawing machines, interlinked with different guiding devices; and
FIG. 8 is a view similar to FIG. 7, but with a six-stage system interlinked with different guiding devices.
US Referenced Citations (10)
Foreign Referenced Citations (5)
| Number |
Date |
Country |
| 96757 |
Aug 1976 |
JPX |
| 549407 |
Nov 1942 |
GBX |
| 603563 |
Jun 1948 |
GBX |
| 655569 |
Jul 1951 |
GBX |
| 1455542 |
Nov 1976 |
GBX |
Continuations (1)
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Number |
Date |
Country |
| Parent |
788782 |
Oct 1985 |
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Patent Grant
4805434
