PLATE STRETCHER AND PLATE STRETCHING METHOD

Abstract

A plate stretcher includes two clamping heads that are directed at one another and can be displaced relative to one another, to apply a clamping force directed along a stretching direction, by way of a pressure element that absorbs the clamping force, and at least one transverse straightener that acts perpendicularly to the clamping force. A method for stretching a plate in a plate stretcher transversely straightens the plate during stretching of the plate.

Claims

1. A plate stretcher comprising: (a) a pressure element; (b) first and second chuck heads directed at and displaceable relative to one another for applying a clamping force directed along a stretching direction by way of the pressure element that absorbs the clamping force; and (c) at least one transverse straightener that acts perpendicularly to the clamping force.

2. The plate stretcher according to claim 1, further comprising a centering unit disposed on a first side of at least the first chuck head, wherein the first side faces the second chuck head.

3. The plate stretcher according to claim 2, further comprising a centering unit carried by the first chuck head.

4. The plate stretcher according to claim 3, wherein the transverse straightener is disposed between the centering unit and at least one clamping jaw provided on the first chuck head.

5. The plate stretcher according to claim 1, wherein the transverse straightener extends into a chuck head mouth of the first chuck head.

6. The plate stretcher according to claim 1, wherein the transverse straightener comprises at least one transverse straightening press that is disposed on the first chuck head.

7. The plate stretcher according to claim 1, wherein the transverse straightener comprises at least first and second transverse straightening presses having respective opposite directions of action.

8. The plate stretcher according to claim 1, wherein the transverse straightener has at least one straightening bar having a direction of action, wherein the at least one straightening bar is divided perpendicularly to the direction of action and perpendicularly to the stretching direction.

9. The plate stretcher according to claim 1, wherein the transverse straightener is displaceable parallel to the stretching direction.

10. The plate stretcher according to claim 6, wherein the at least one transverse straightening press is displaceable parallel to the stretching direction.

11. A plate stretching method for stretching a plate in a plate stretcher comprising: (a) stretching the plate; and (b) transversely straightening the plate during stretching of the plate.

12. The plate stretching method according to claim 11, wherein a transverse straightener is used for transverse straightening and wherein the transverse straightener follows a movement of the plate (12) during stretching, in a stretching direction.

13. The plate stretching method according to claim 12, wherein the transverse straightener freely follows the movement of the plate during stretching.

14. The plate stretching method according to claim 11, wherein the plate is transversely straightened between a centering unit provided on a chuck head and at least one clamping jaw provided on the chuck head.

Description

IN THE DRAWINGS

[0034] FIG. 1 shows a first plate stretcher in a schematic side view;

[0035] FIG. 2 shows the plate stretcher according to FIG. 1 in a schematic top view;

[0036] FIG. 3 shows a second plate stretcher in a schematic side view; and

[0037] FIG. 4 shows the plate stretcher according to FIG. 3 in a schematic top view.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0038] The plate stretchers 10 shown in the figures comprise two clamping or chuck heads 20, each having sides 22 that are directed at one another.

[0039] The chuck heads 20 are displaceable relative to one another; this displaceability is shown symbolically by means of wheels 26 here. In this regard, both chuck heads 20 are displaceable in the exemplary embodiment according to FIGS. 1 and 2, while in the exemplary embodiment according to FIGS. 3 and 4, one of the, chuck heads 20 is configured to be fixed in place, and the other of the two chuck heads 20 is configured to be displaceable, as a counter chuck head. It is understood that ultimately, depending on the concrete implementation of these exemplary embodiments, other displacement possibilities can also be provided for deviating exemplary embodiments, and, in particular, mounting possibilities deviating from wheels 26 can also be provided, and that in deviating exemplary embodiments, the displacement possibilities of the two exemplary embodiments according to FIGS. 1 to 4 can also be interchanged.

[0040] The clamping or chuck heads 20 each have a clamping or chuck head mouth 21 that opens toward the side 22 of the chuck heads 20 that faces the other chuck head 20, in each instance, by means of which the chuck heads 20 can hold a plate 12 or other workpieces to be stretched, such as metal sheets or the like.

[0041] In the chuck head mouth 21, clamping jaws 24 are provided on both sides of a clamping plane 18, by way of which jaws the plate 12 or the workpieces can be clamped using the chuck heads 20, in each instance.

[0042] In the case of both exemplary embodiments, the chuck heads 20 are connected to act with pressure bars 14 that are provided parallel to one another in the clamping plane 18, on both sides of the chuck heads 20, and form the pressure element in these exemplary embodiments.

[0043] Not shown, because they are sufficiently known from the state of the art, are drives by means of which the chuck heads 20 can be displaced relative to one another. Usually, motor-driven, particularly hydraulic drives are provided here, which displace at least one of the chuck heads 20 relative to the pressure element in the stretching direction 16, which lies in the clamping plane 18. It is understood that in the case of deviating embodiments of the pressure element, other types of drives are also provided, wherein ultimately, the only important thing is that the chuck heads 20 are displaced relative to one another to apply a clamping force in the stretching direction 16. Ultimately, in the present connection it only plays a subordinate role in what way this displacement is brought about or how the stretching or clamping force that acts in the stretching direction 16 is applied or compensated.

[0044] In the exemplary embodiment shown in FIGS. 3 and 4, the pressure bars 14 have openings that are not numbered but are shown in the drawing, by way of which openings the displaceable chuck head 20 can be locked onto the pressure bar 14 at different distances from the other chuck head 20. The same can also be provided in the exemplary embodiment provided in FIGS. 1 and 2. Also, in this regard, other adjustment possibilities, such as spindles, wedge connections, gear teeth, and the like, can also be provided in deviating embodiments.

[0045] Both of the plate stretchers 10 shown in the figures each have centering units 40 that are disposed ahead of the chuck head mouth 21 of the chuck heads 20, in each instance. It is understood that in deviating embodiments, such centering devices or others can also be provided at a different location or in movable form.

[0046] The centering units 40 each have centering bars 42 disposed on both sides of the clamping plane 18, which bars each carry centering rollers 44, thereby making it simpler to center a plate 12 or another workpiece that is supposed to be applied to the plate stretcher 10, in each instance, with reference to the clamping plane 18, before the plate 12 gets into the respective chuck head mouth 21 all the way to the clamping jaws 24. In this regard, the centering rollers 44 serve to prevent undesirable markings on the respective workpiece or on the plate 12. It is understood that here, deviating solutions can easily be used accordingly in deviating embodiments, if applicable. In particular, it is conceivable, for example, to provide a centering bar 42 only on the underside or only on one side of the clamping plane 18.

[0047] Likewise, transverse centering units, which are not shown here but are sufficiently known from the state of the art, by means of which the plate 12 or the workpiece can be centered in the clamping plane 18 and, in particular, perpendicular to the stretching direction 16, can be provided.

[0048] Both of the plate stretchers 10 shown in the figures have a transverse straightener 30 that is indicated merely by a general arrow, because it extends almost over the entire plate stretcher 10 with its different modules.

[0049] In detail, the transverse straighteners 30 of the two plate stretchers 10 shown in the figures comprise transverse straightening presses 32 that can act on the plate 12 or the corresponding workpiece in different directions of action 31 with reference to the clamping plane 18.

[0050] The transverse straightening presses 32 are, among other things, two transverse straightening presses 32, in each instance, that are provided in the two chuck heads 20 with opposite directions of action 31. Supplementally, the plate stretcher 10 shown in FIGS. 1 and 2 has two transverse straightening presses 32 that can act on the plate 12 or on a workpiece with opposite directions of action 31 in the interstice between the two chuck heads 20. In the exemplary embodiment shown in FIGS. 3 and 4, in contrast, only one transverse straightening press 32 is provided in the interstice between the two chuck heads 20, which press can act on the plate 12 or a workpiece in only one direction, in the present exemplary embodiment from below, but this action can also take place from above, if applicable. Taking place from above is non-critical in that if applicable, the plate 12 or the corresponding workpiece can also be clamped in the plate stretcher 10 in turned manner, if transverse straightening is supposed to take place from the other side of the plate 12 or of the workpiece. It is understood that also in the case of the exemplary embodiment according to FIGS. 3 and 4, the arrangement of the transverse straightening presses 32 of the exemplary embodiment according to FIGS. 1 and 2 can be provided—and vice versa. Likewise, it is understood that individual transverse straightening presses can be left out on the chuck heads if these presses are considered unnecessary in an individual case.

[0051] All of the transverse straightening presses that are shown in the present exemplary embodiments each have a straightening bar 34 that can be positioned perpendicular to the clamping plane 18 in the positioning direction 35 (merely shown in detail with regard to the larger transverse straightening presses 32). In this manner, transverse straightening processes can be easily carried out accordingly, in each instance. In the case of the present exemplary embodiments, positioning takes place by means of corresponding cylinders or cylinder/piston units. Depending on the concrete implementation, short-stroke cylinders are possible in this regard, particularly for the transverse straightening presses 32 that are provided on the chuck heads 20.

[0052] The transverse straightening presses 32 disposed on the chuck heads 20 have supports 36 that carry the straightening bar 34, on the one hand, and the means for positioning the straightening bar 34, such as the short-stroke cylinders, for example, on the other hand. The supports can furthermore be displaced on the chuck heads 20 by way of rails 38, so that on the one hand, they can be positioned in targeted manner for transverse straightening, and on the other hand they can follow possible material movements of the plate 12 or of the workpiece during stretching. The rails 38 are accordingly oriented parallel to a displacement direction 33, wherein the other transverse straightening presses 32 can also be displaced along the displacement direction 33, something that is correspondingly advantageous.

[0053] In this regard, in the exemplary embodiment according to FIGS. 3 and 4 the path length that the rails 38 make possible is configured to be longer than in the exemplary embodiment according to FIGS. 1 and 2. It is understood that depending on the concrete requirements, a corresponding path length can be made possible.

[0054] If applicable, it is also possible to do without a displacement, particularly during the stretching process, if the relative movement to be expected between the respective transverse straightening press 32 and the plate 12 or the workpiece is very slight. This case occurs, for example, if the transverse straightening press 32 is disposed very close to the clamping jaws 24 or also precisely in the middle between the two chuck heads 20 of the plate stretcher 10 according to FIGS. 1 and 2.

[0055] In deviating embodiments, positioning of the transverse straightening presses 32, which is provided on the chuck heads 20, can also take place in that the rails 38, in which the support 36 or actually the straightening bar 34 then runs, can be positioned accordingly.

[0056] In the case of the plate stretcher 10 shown in FIGS. 3 and 4, the straightening bars 34 of the transverse straightening press 32 are furthermore configured to be divided, and have individual elements 39. It is understood that this feature can also be provided, only for individual transverse straightening presses 32 of the corresponding plate stretcher 10, in the case of deviating exemplary embodiments. Likewise, this feature can also be provided in the case of the arrangement according to FIGS. 1 and 2, for one or individual ones of the transverse straightening presses 32 or also for all the transverse straightening presses 32.

[0057] In this regard, the individual elements 39 can also be positioned by means of individual cylinders, more precisely by means of individual short-stroke cylinders. Particularly in the case of transverse straightening presses 32 that are provided between chuck heads 20 and not on chuck heads 20, other cylinders or supplementally, cylinders for greater strokes can also be provided. It is understood that if applicable, multiple of the individual elements 39 can also be coupled, for example coupled hydraulically. Likewise, it is conceivable that individual elements 39 are also structured to be rigid, but this arrangement appears to be conceivable only for special cases, for example for elements on the lateral edge of the chuck head mouth 21.

[0058] Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.