METHOD AND APPARATUS FOR PLATE BENDING

TECHNICAL FIELD

Method and apparatus for plate bending.

BACKGROUND ART

Metal plates are bent, edged and pressed into different profiles in order to increase their rigidity. Bending and edging is also used to connect plates to each other. Profiled metal plate products are used as roofs and facade covers. Profiled roof products are usually manufactured with a rotary press and three-dimensional figures, such as cover products with tile patterns, are first pressed with a rotary press and then with a flat press.

Rotary and flat presses are expensive and have to be used to produce large quantities of certain pattern at once. Changing the pattern or scale is very expensive. Only profile products with a limited deflection angle can be produced with the methods mentioned above. For instance, an angle larger than 90° cannot be achieved with a flat press or rotary press.

There are several examples of metal plate bending apparatuses in patent literature, with which complex forms can be bent, e.g. US patent 6,640,600. The bending apparatus in this example, however, can only bend complex forms close to the edge of the plate. Plates are very often only bent near the edge.

Roof products and other architectonic wall covers are, however, large and possibly long plates and still required to be rigid and therefore high profiled. Plate products, in which a deflection angle of over 90° is preferred, are for instance connection plates used in concrete pouring. With an angle of over 90°, the so called dovetail effect can be achieved

with which the grab spikes, which weaken the strength of present connecting plate solutions, could be at least partially replaced.

The object of the invention is therefore to develop a method with which plates can be bent into different profiles individually and in small series.

SUMMARY OF THE INVENTION

In the method of the invention, a plate is bent using a bending apparatus, which comprises a body with an opening in it for the insertion of the plate into the apparatus, retaining means for the retaining of the plate and a bending mechanism for the bending of the plate. The plate is set into a standard position, the plate is turned from the point to be bent in the desired direction with the bending mechanism, and the bending apparatus is turned so that the retaining means of the plate turn in the opposite direction of the bending direction.

The invention is also concerned with a bending apparatus performing the method, which is mainly characterized in that the retaining means of the plate are inside the body in order to keep the plate in the standard position, the bending mechanism has means for the turning of the plate in the desired direction, and the bending apparatus has means for the tuning of the bending apparatus in such a way that the retaining means turn in the opposite direction of the bending direction.

The preferable embodiments of the invention have the characteristics of the sub claims.

In practice the plate is set into the standard position by first inserting it into the bending apparatus and the bending point is set by moving the plate out of the apparatus the distance to be bent.

With the new invention, plates can be bent into different profiles individually and in small series and thereby allowing for instance attention to be pointed to architect drawings in a new way. The invention can also be used to produce fan-shaped profiles from large plates,

which can be used for covering cone like roofs, in such a way that the width of the profile narrows when going up.

In usual procedures, a large plate, which is bent in for instance 90° angles, would also move in a 90 degree angle, in which case damage to the whole product would be probable. Now the invention has developed an apparatus, in which the body of the entire apparatus and its bending end turn as the plate to be bent turns.

In the following, a preferable embodiment of the invention will be presented with the help of figures. Other embodiments are possible within the scope of the patent claims and the invention is not limited to the embodiment presented. The bending mechanism can for instance be an other than presented in the figures.

FIGURES

In figure 1 , the apparatus of the invention is in a horizontal position for the insertion of the plate into it

In figure 2, the apparatus of the invention is in a vertical position in order to keep the plate in position for the bending

Figure 3 presents the plate of the apparatus presented in figure 1 and 2 and the means for moving it

Figure 4 presents, in detail, the bending mechanism of the apparatus of the invention

In figure 5, the apparatus of the invention is in a turned position for the duration of the bending of the piate

In figure 6, the apparatus of the invention is connected to a belt support apparatus for the supporting of the bent plate

In figure 7, the apparatus of the invention is connected to a airbag apparatus for the supporting of the bent plate Figures 8a - 8d present examples of plate forms which have been bent using the method of the invention.

DETAILED DESCRIPTION

In figure 1 , the plate-bending apparatus of the invention is in the horizontal position for the insertion of the plate 6. The plate-bending apparatus comprises the body 1 , which has an opening for the insertion of the plate 6. The plate 6 is held by the plate clamps 8. The bending apparatus of the invention has to be turned around its axis 14. The plate clamps 8 are illustrated better in figure 4.

The bending apparatus is, in the beginning of the plate handling, advantageously in the horizontal position which is the position it is in when the plate 6 is inserted into the apparatus. When the plate 6 has been inserted into the apparatus it is advantageously turned in the vertical position of figure 2.

In figure 3, the means 4 for the turning and lifting of the plate 6 straight or diagonally upwards. The means 4 function for instance electrically or hydraulically. In figure 3, the plate 6 is tilted in order to show that the means for turning and lifting (i.e. the means for moving the plate) 4 do not necessarily have to be in the same position, but can be turned independently in order to produce different profiles.

A bending mechanism of figure 4 is advantageously used in the invention. In figure 4, the bending point of the plate is shown in detail in connection with the advantageously used bending mechanism. The plate 6 is held with clamps 8, which have been constructed of two metallic clamp parts A1 , B1 and two turning and twisting bending clamp parts A2, B2.

The clamps, of which A1-B1 , thus, are holding clamps and of which A2-B2 are bending clamps, are fastened to each other with an elastomer 9, in such a way that A1-A2 are parts of the same uniform product, which can be exchanged, so that the length of the elastomer, in other words the distance between the metal parts of the clamps, can be varied. With a longer distance a bigger radius of bending can be achieved. A great number of different radii of bending can be combined by means of a hydraulic fluid tube left inside the clamps, a belt with a varying thickness left there between an the length of the elastomer between the clamps.

The elastomer material 9, between the clamp parts A1 , B1 , stretches and squashes during the bending of the plate. The clamp parts A1 and A2 do not move in relation to the material being bent, i.e. the plate 6. Clamp parts A, B can advantageously also be at least partly covered with elastomer material.

The elastomer 9 between the clamp series A and B can be pre-stretched with for instance a hydraulic fluid. The pre-stretching results in a change in the radius of the angle of the plate to be edged. The hydraulic fluid is preferably in a fibre-reinforced hose 3, which has been left in place after having cast the elastomer. The radius of bending of the bending angle can in some extent be adjusted with the pressure of the water or other fluid.

The holding clamps A1-B1 are thus in fixed but flexible connection with the bending clamps A2-B2, the bending clamps A2-B2 being additionally both-sided, so that they at the same time form stoppers to each other.

The torque for the advantageous bending mechanism of the invention is provided by pressurised air beams 11 , which are filled with pressurised air, which leads to the bending of the clamps A2-B2. The clamps A, B have grooves, in which there is a flexible and porous pipe which is activated with pressurised air whenever the plate is moved in the direction of the clamps and from which air erupts, which release the direct friction contact between the clamps and the plate 6 to be worked (bent).

The clamps 8 consist of two metal holding clamp parts A1 , B1 and two turning bending clamp parts A2, B2.

For the bending of the plate 6, the movement means 4 lift the plate 6 for the bending distance either straight or diagonally after which the pressing clamps A1 , B1 of the plate 6 holding clamps 8 close. After this, the turning clamps A2, B2 start turning the part of the plate which has been pushed out for instance to the left and the holding clamp parts A1 , B1 start turning to the right at the same speed. In figure 5, the plate bending machinery is presented in a turned position attached to the body 2, in a situation where the plate 6 has already been bent a couple of times in different directions.

After the plate 6 has been turned a sufficient number of times it starts to come out of the apparatus and starts to need support. The support can either be airbags 15, as shown in figure 7, or belts 3 running on both sides, advantageously belts as shown in figure 6.

When the plate has been bent, corrugated and edged as intended, the space between the belts 3 closes and the belts 3 take the plate 6 away to, for instance, storage.

In another embodiment, a light but fragile plate 6 stays in place and comes out of the machine as it is being formed, but the heavy and mechanically enduring bending machine is turned in such a way that the plate stays in its place the whole time, usually vertically. The bending could be performed in any case but the arrangement would be more complicated.

It has to be noted that although the plate 6 essentially stays in the upright position, it still moves horizontally and vertically as the end of the plate holding clamp 8 ascends and descends. The belts 3 or airbags 15 which support the plate move naturally, mechanically attached, in the same direction as the plate.

The movement means 4 can be adjusted in such a way that the angle of the plate 6 changes in relation to the angle of the holding means and bending means, which means that wedge-shaped patterns can be achieved. These kinds of profiles are needed and are advantageous to use in for instance roof plating and especially for cone-like roof cover plating. Furthermore, a snow blocking effect can be achieved with wedge-shaped slottings even for a straight an even roof without any separate snow-blocking device, when the slotting narrows when going downwards in a sloping roof.

Figures 8a - 8d present examples of products that can be inexpensively manufactured with the apparatus and method of the invention. Notice that fan-shaped, differentiated profiles and irregular plate bending can freely be manufactured.

Individual products or small series of profiled plate products, which are not damaged by the bending, and such profiles in which adjacent profiles vary in height with deflection

angles of over 90°, can be manufactured using the method. Furthermore, fan-shaped profiles can easily be manufactured, one end of which is broader than the other. The method is suitable for special products and the needs of free form architecture.