Method and apparatus in a bending machine

Abstract: The invention relates to a method and apparatus for adjusting the width of the bending jaws in a bending machine. The total width (L) of the bending jaws is formed by using jaw parts and edge pieces in the following manner: a first set (R₁) is elected to form a group of jaw parts of different widths for so-called fine adjustment, one at a time .(R 1n ) being at the operational point (T) of the bending jaws, a second set (R₂) is elected to form a group of jaw parts with identical width and to be separate from the edge pieces (RK₁, RK₂) for so-called coarse adjustment, wherein the width of the bending jaws required at a time is elected according to the equation L = R 1n + N * R 2i + C, wherein L = the width of the bending jaws, R 1n = the width of the jaw part (n = 0...M) elected from the first set (R₁), N = the width of the jaw parts of the second set (R₂), i.e. a constant, R 2i = the number (i = 0...k) of jaw parts of the second set (R₂) at the operational point (T) of the bending jaws, and C = a constant, comprising the parts with a constant width included in the total width of the bending jaws, i.e. preferably at least the total width (C R ) of the edge pieces (RK₁, RK₂) and the total width (C L ) of the locking parts (LO) between the first and second sets.

Description: The invention relates to an apparatus for adjusting the width of the bending jaws of a bending machine, as indicated in the preamble of claim 1, as well as to a method to be used with such an apparatus. From patent publications, several solutions are known for adjusting the width of the bending jaws of a bending machine. As to the state of art, reference can be made e.g. to the publication EP-A-105091, which discloses a tool length changing device which is essentially similar to that presented above. The bending jaws comprise two sets of jaw parts, whereby the first set comprises a number of narrow plates corresponding to the shape of the bending jaws, the number of plates in connection with the bending jaws being adjustable, whereby said plates are used for fine adjustment of the width of the bending jaws. At both sides of the first set, the second set of jaw parts is provided, forming the unit for coarse adjustment of the width of the bending jaws, whereby each piece of the second set, at its end face, which extends substantially outwards from the bending jaws in the longitudinal direction of the bending jaws, comprises a protruding arrangement intended for making possible the function of the bending jaws at the stage of bending particularly the two last edges of the four edges of the sheet. The above-presented method and apparatus are relatively difficult to apply into practice particularly because the edge pieces are usually relatively wide in the longitudinal direction of the bending jaws, whereby for fine adjustment, a relatively large number of plates is needed, from which a certain group must be selected for fine adjustment. Furthermore, this construction is expensive, because it contains numerous specially made edge pieces. On the state of art,- reference is also made to the publications US-4, 722,214, US-4,761,985, US-4,875,171, and US-4,856,315. These publications disclose solutions of prior art. In general, they have the disadvantages of the device of EP-A-105091 presented above, and they are very complicated in construction and function. US-A-4 660 402 discloses an apparatus and method for using it in accordance with the preamble of claims 1 and 18, respectively. It is the purpose of this invention to present a method whereby the disadvantages of prior art can be eliminated to a maximum extent and thus to improve the state of art in adjusting the width of the bending jaws of a bending machine. The solution according to the invention is particularly related to the applications of a bending machine using automatic tool change techniques. The apparatus according to the invention makes it possible to apply the method of the invention as indicated in the appended claims. The present solution provides the advantage that the width of the bending jaws of the bending machine can be adjusted in a quick and reliable manner by using simple functional parts. The first set of jaw parts makes up a set for so-called fine adjustment. Thus their difference in width is preferably defined to be constant, whereby the interval for adjusting the total width is equal to the difference in width of the jaw parts of the first set. On the other hand, the width of the jaw parts of the second set is also elected to be constant, and they are used for so-called coarse adjustment of the total width of the bending jaws. Thus, when applying the method, the number of jaw parts of the second group is elected first to obtain a so-called coarse measurement range for the total width. After this, that jaw part is selected from the first set which is most suitable for obtaining the total width of the bending jaws needed for the bending purpose. The method is particularly advantageous, because the jaw parts of the second set are simple plates, and there are only two edge pieces that make up a kind of a third set, the width being a constant to be considered in determining the total width of the bending jaws. In the following, the invention will be described in more detail with reference to the appended drawings. In the drawings, Figs. 1 to 3 illustrate a bending machine applying the method and apparatus of the invention, seen from two sides and from above, Figs. 4 to 6 illustrate schematically the operating principle of the method of the invention, Figs. 7 to 8 show schematically two alternative embodiments of exchanging jaw parts of the first set in connection with adjusting the total width of the bending jaws as steps a to f, whereby the left-hand series I in each partial figure a to f shows the respective step as seen from the side of the bending mchine in a direction perpendicular to the longitudinal direction of the bending jaws, and the partial figure II shows the respective situation as seen in a direction perpendicular to the direction of the series I (in the longitudinal direction of the bending jaws), Fig. 9 shows the exchange of the jaw parts of the second set, its first embodiment in steps a to 1, whereby the series I and II correspond to the direction of the previous figures 7 and 8 and the series III shows the corresponding situation seen from above, Fig. 10 shows the exchange of the jaw parts of the second set in a second embodiment also as steps a to 1 and series I, II and III, Fig. 11 shows the exchange of the jaw parts of the second set in a third embodiment as steps a to n and series I, II and III, Fig. 12 shows the exchange of the jaw parts of the second set in a fourth embodiment as steps a to o and series I, II and III, Fig. 13 shows the special structures of the bending jaws for carrying out clamping and transfer operations in a schematic view seen in a direction perpendicular to the longitudinal direction of the bending jaws, Fig. 14 shows the fastening and detaching of the jaw part of the first set in connection with the bending jaws, seen in a direction perpendicular to the longitudinal direction of the bending jaws, Fig. 15 shows the structure of a jaw of the second set and also its fastening and detaching, seen in a direction perpendicular to the longitudinal direction of the bending jaws, and Fig. 16 shows a partially enlarged view A of Fig. 14 in a locking situation. Figures 1 to 3 illustrate a bending machine for applying the method and apparatus for adjusting the width of the bending jaws of a bending machine according to the invention. The bending machine comprises as main parts a frame 1, bending jaws 2a, 2b in the frame 1, of which the lower jaw 2a being stationary in the frame 1 and the upper jaw 2b being movable in the vertical direction for pressing the sheet to be bent between the bending jaws 2a, 2b. The invention is applied particularly in connection with the upper jaw 2b. Further, the bending machine comprises a movable bending jaw arrangement 3a, 3b in a frame structure 4 articulated in the frame 1 and having a C-form when seen in a cross-section perpendicular to the longitudinal direction of the bending machine, whereby the sheet between the bending jaws 2a, 2b in the frame 1 can be bent both from above and from below either by a lower bending jaw 3a or by an upper bending jaw 3b of the bending jaw arrangement 3 in the gap 5 of the C-formed frame 4. The bending machine is also provided with a support table 6 for the sheet to be bent. The support table 6 is equipped with a transfer device 7 for moving the sheet to be bent in a linear direction towards and away from the bending jaws 2a, 2b; 3a, 3b. In the embodiment shown in Figs. 1 to 3, there is also a transfer system for the sheets to be bent, comprising a frame part 8 provided with a horizontal arm 9. In this arm, a movable gripping device 10 is arranged for gripping a pile of sheets placed on the side of the frame 8, -the uppermost sheet 11 thereof, from above, e.g. by a suction pad arrangement 12 in connection with the gripping device 10. In addition to the vertical movement, the gripping device 10 is arranged to rotate around a vertical axis, whereby it can, when operating on the support table 6, always turn the edge of the sheet 11 to be bent next in alignment with the longitudinal direction of the bending jaws 2a, 2b; 3a, 3b upon the many different stages of bending are being carried out. After the sheet 11 has been bent a pre-determined series of times, it is transferred onto the transfer table 13 and to further processing of the bent sheet. Figures 1 to 3 also show a main distribution board with the reference number 14 and a central unit with the reference number 15. The operations of the bending machine and the devices connected therewith are automated, whereby the bending operations of the sheet to be bent and the readjustments between the bending operations are carried out on the basis of instructions by the programmed automatics to the actuator. In many practical embodiments, the width of the bending jaws must be narrowed particularly in connection with bending the third and fourth edges of a rectangular sheet in order to be able to lift the bending jaw, particularly the upper bending jaw 2b in the frame 1, without being prevented by the first and second edge bending of the sheet. For this purpose, the bending jaw used in the method of the invention can be programmed in a way that the jaw part R 1n of the first set is temporarily removed from the connection of the bending jaw to an exchange position where it does not prevent the jaws R 2i of the second set from moving towards each other, whereby the width of the bending jaws is made temporarily narrower than its operational width and it [?] can be removed upwards without being prevented by the first and second edge bendings, and the bent sheet can thus be released to be removed from between the clamp jaws. The purpose of this invention is particularly to present a method and an apparatus, whereby upon bending a sheet in several stages, the most critical width of the bending jaws, i.e. the width of the upper, vertically movable bending jaw 2b (the clamp jaw) of the bending machine, can be adjusted by degrees. The basic idea of the invention is schematically illustrated particularly in Fig. 4. The bending jaw comprises: a) two sets (R 1 , R 2 ) of bending jaws, which are, for adjusting the width of the bending jaws, moved and/or exchanged from an operational point T to a non-operational point ET, and b) parts of standard width, the most important parts being the edge pieces RK 1 , RK 2 at both ends of the bending jaw, forming some kind of a third set. The non-operational points are preferably in connection with the bending machine and form a first storage EV for the jaw parts of the first set R 1 and a second storage TV (TV 1 , TV 2 ) for the jaw parts of the second set R 2 . The second storage TV consists of two parts, being placed on both sides of the operational width L of the bending jaws. According to the invention, the jaw part R 1n of the first set in the operational position T is placed in the middle of the bending jaws, and the jaw parts R 2i of the second set in the operational position T are placed on both sides of the jaw part R 1n of the first set. At the edges of the bending jaws, there are also edge pieces RK 1 and RK 2 of the bending jaws, determining the total width of the bending jaws. As shown in Fig. 4, the width L of the bending jaws is determined by electing a certain jaw part R 1n from the first set. The first set R 1 is elected to comprise a group of jaw parts of the first set with different width, intended for fine adjustment of the width of the bending jaws. Only one (R 1n ) of the jaw parts of the first set (R 1 ) is in operational connection with the bending jaws at a time. The second set R 2 is elected to comprise a group of plate-likejaw parts with equal width, whereby the jaw parts R 2i of the second set in the operational position are intended for coarse adjustment of the width of the bending jaws. The total width L of the bending jaws is formed by a formula which is programmed in the programming logistics of the bending machine according to the dimensions of the quantities affecting the width of the jaw parts R 1 , R 2 and of the edge parts RK 1 , RK 2 etc. and according to the strategy of electing the width of the bending jaws. The total width L is elected according to the formula presented above, using the references of Fig. 4. Thus particularly the constant C in the equation presented on the width of the bending jaws is substantially composed of four partial constants, which are the widths C R of the edge pieces RK 1 and RK 2 and the widths C L of the locking pieces of the center part KO. Figure 5 shows the operating principle of the method of the invention in a schematic drawing L = f (R 1 , R 2 ). Thus the coarse adjustment is made by election of the number of jaw parts R 2i of the second set R 2 in the operational position T, whereby the bending width is gradual P for the coarse adjustment, as shown in Fig. 5. For the range of each coarse adjustment step P, a certain jaw part R 1n can be elected from the first set R 1 , in this example from seven jaw parts (n = 1...M, M = 7). The difference LE in the widths of successive jaw parts of the first set is constant. This width difference constant LE is divided evenly in the range of the coarse adjustment step P so that the minimum deviation MP of the total width L of the bending jaws is the difference LE in the widths of jaw parts of the first set R 1 . In Fig. 5, the minimum deviation is indicated with the reference MP. This gives a series of ascending or descending steps of functional total widths L of the bending jaws, from which the desired total width L can be selected on the basis of the dimensions of the first and second set. For example, the total width L(1) of a bending jaw shown in Fig. 5 is, using the index markings of Fig. 5: the jaw part R 1,6 is elected from the first set (n = 6) and the number of jaw parts of the second set is R 2,6 (i = 6). The width of each jaw part of the second set R 2 is N. It should be noted that the rarely used minimum total width L of the bending jaws corresponds to the width of the constant C in Formula 1, when R 1n = 0 and R 2i = 0. In the application of the operational principle shown in Fig. 5, the number of jaw parts of the second set R 2i is thus elected to be even, and the jaw parts of the second set R 2 are then placed symmetrically on both sides of the bending jaw structure so that the jaw part R 1n of the first set and the center part KO are placed centrally in the width of the bending jaws. Consequently, in the equation on the total width of the bending jaws (Formula 1), the index i in the term R 2i is an even number and the step P = 2 * N. As shown particularly in Fig. 6, the number M of jaw parts of the first set R 1 can be elected so that M = N LE or M = 2 * N LE Consequently, M = number of jaw parts in the first set R 1 , N or 2*N = width of each jaw part or two jaw parts of the second set R 2 , and LE = constant difference in the width of successive jaw parts, e.g. R 1,n and R 1,n+1 , in the series of jaw parts of the first set R 1 . Further using the references of Fig. 6, it can be stated that the width of jaw parts of the first set R 1 can be elected so that it complies with the condition KL n = C M + K (k) * LE wherein KL n = the width of a certain jaw part R 1,n of the first set R 1 , wherein n receives a value from 1...M, M being the number of jaw parts, C M = a constant measurement, i.e. the basic width of jaw parts of the first set R 1 , K (k) = a coefficient that receives in the formula a value 0, 1, 2, ... to M-1, M being the number of jaw parts, and LE = the constant difference in the width of successive jaw parts, e.g. R 1,n and R 1,n+1 , in the series of jaw parts of the first set R 1 . This solution gives the advantage that a continuous constant difference LE in the width is obtained as shown in Fig. 5, although moving one or several steps upwards or downwards in the coarse adjustment; also, the number of jaw parts can be minimized. Particularly Fig. 6 shows a variation in which N or 2*N = the numerical value 100 (i.e. the width of jaw parts of the second set has the numerical value of either 100 or 50) and LE = the numerical value 10, from which it follows that there are a total of ten jaw parts in the first set R 1 (Formulas 2 and 3). Further, if the constant C M = the numerical value 100, the width of the first jaw part R 1,1 of the first set R 1 is KL 1 = the numerical value 100. Consequently, using the markings of Fig. 6, e.g. the width KL 8 of the eighth jaw part R 1,8 of the first set R 1 is 170. When electing the width of the constant C M , particular attention is paid to the temporary needs for narrowing the total width L when the bending jaw is lifted in connection with bending the third and fourth edges of the sheet to be bent. In calculation, the constant C M can be included in the constant C of the equation for defining the width of the bending jaws (Formula 1). Further according to the method, the total width C K of the edge piece RK 1 , RK 2 (Fig. 4), C K > C R ) in the longitudinal direction of the bending jaws is elected to substantially correspond to, or to be smaller than, the joint width LM * N of jaw parts of the jaw part series PL M to be removed from the second set R 2 . If necessary, the method is used, in connection with changing the total width L of the bending jaws, for removing a series of jaw parts of the second set R 2 (jaw part series PL M ) from both ends of the bending jaws and placing the edge pieces RK 1 , RK 2 in the openings thus formed, these being thus preferably wider than the width C K of the edge pieces in the longitudinal direction of the bending jaws. Naturally prior to this operation, the jaw parts of the second set R 2 , removed for the previous width adjustment of the bending jaws, are returned to connection with the bending jaws, at the removal point of the edge pieces RK 1 , RK 2 , and/or the jaw parts of the second set R 2 are compressed into a uniform set. Thus, between the width C K of the edge pieces RK 1 , RK 2 and the jaw part series PL M of the second set R 2 , there is a relation LM * N ≥ C K wherein LM is the number of those jaw parts in the second set R 2 which, in connection with each adjustment of the width of the bending jaws, are removed as a series PL M of adjacent jaw parts and wherein N is the width of each plate-like jaw part with standard thickness of the second set R 2 in the longitudinal direction of the bending jaws, i.e. a constant. For example, if C K = the numerical value 700 and N = the numerical value 100, there is e.g. in connection with the second storage TV 1 and TV 2 in certain embodiments of the invention a jaw part series PL M consisting of seven jaw parts on both sides of the bending jaws of the bending machine, at the non-operational position ET (Fig. 4). Particularly in Figs. 7 and 8, the exchange of a jaw part of the first set R 1 is shown in two alternative embodiments. The jaw parts of the first set R 1 are placed in connection with the first storage EV. The jaw part R 1n in the operational position in connection with the bending jaws is exchanged by a transfer device 16 effective between the first storage EV and substantially the location S of the jaw part R 1n . In Fig. 7, the exchange of the jaw part of the first set is shown in steps a to f. Thus the partial figure a shows the starting point when the previous bending programme is finished and the next bending programme to be carried out by the bending machine requires the exchange of a jaw part of the first set. Thus also the first storage EV moves in relation to the frame 1 of the working machine so that the jaw part R 1m of the first set R 1 to be used next comes against the first gripping means 17 of the transfer device 16, which grips said jaw part R 1m . The jaw parts of the first set can be placed in a row in connection with the first storage EV, whereby the programming logistics required for the exchange becomes simple. The first transfer device 16 comprises a transfer arm 19 which is arranged to be pivotable by actuators (not shown) in the vertical plane in front of the frame 1 around a horizontal shaft 18 fixed in the frame 1, e.g. in a lug 18a, said first gripping means 17 being placed at the free end of the transfer arm 19. With particular reference to partial figure 7b, the locking of the jaw part R 1n of the first set R 1 in the location S is simultaneously released by moving at least those jaw parts R 2i of the second set R 2 which are in the operational position aside in the longitudinal direction of the bending jaws, whereby the locking of the jaw part R 1n is released and it can be lifted in the vertical plane in relation to the frame 1 by a movable support device 22, the jaw part R 1n being fixed thereto, into a first exchange position VA1. At the same time, the transfer arm 19 of the first transfer device 16 revolves into the low position (clockwise in Fig. 7b) in front of the frame 1, i.e. about 180°, the transfer arm 19 pointing substantially downwards. Thus the second gripping means 20 in the first transfer device 16 is placed so that it can grip the jaw part R 1n in the first exchange position VA1 in a manner corresponding to that described above in connection with the jaw part R 1m (cf. Fig. 14). This step is shown in partial figure 7c. When both jaw parts R 1n and R 1m are in connection with the gripping means 17, 20, the transfer arm 19 is turned e.g. about 10° around the shaft 18 (counterclockwise in Fig. 7d), whereby the rotary frame 21 provided at the end of the transfer arm 19 and fixed with the gripping means 17, 20, is released to rotate the first and second gripping means 17, 20 and the jaw parts R 1n and R 1m 180° around the longitudinal axis of the transfer arm 19 by a rotating device 21a effective between the transfer arm 19 and the rotary frame 21. Thus a return takes place from the above-mentioned situation of Fig. 7d to the situation of Fig. 7e, in which the jaw part R 1m is in the first exchange position VA1, gripping the support device 22 in the frame 1 of the bending machine. At the same time, a movement takes place in the first storage EV so that the jaw part R 1n to be returned there is placed in its position in the first storage EV. In the situation of Fig. 7f, the jaw part R 1n is returned to the first storage EV and the jaw parts R 2i of the second set are pressed against the jaw part of the first set R 1m , placed by a downwards movement of the support device 22 from the exchange position VA1 into the location S. Fig. 8 shows an alternative way of carrying out the exchange of the jaw part of the first set R 1n → R 1m . The steps presented are substantially similar to those shown in Fig. 7, only with the exception that the jaw parts R 1n → R 1m are exchanged directly at the location S, without any separate step of moving the jaw part from the location S to the exchange position VA1 and vice versa. The location of the exchange position VA1 may correspond to the point to which the jaw part of the first set is moved when narrowing the width in connection with lifting the bending jaws for bringing it away from below the edge bendings. Fig. 9 shows the exchange of jaw parts of the second set in steps a to 1, as the first embodiment of said exchange. Fig. 9a shows the starting point, when the previous bending programme is finished and the next bending programme to be carried out by the bending machine requires the exchange of the operational jaw parts R 2i of the second set with the particular purpose of moving the edge pieces RK 1 , RK 2 to a new position for adjusting the total width. Thus, in the first step, the jaw part R 1n of the first set is released from the locking and transferred into the exchange position VA1 (for a possible exchange carried out simultaneously, as shown in Fig. 7) and the jaw parts R 2i of the second set are moved in opposite directions in the longitudinal direction of the bending jaws, whereby they are placed in the exchange position VA1. As shown particularly in Fig. 9a, there is a jaw part series PL M1 at both sides of the bending machine, at both ends of the bending jaws, the width of the series corresponding to or exceeding the width C K of the edge piece (RK 1 , RK 2 ). These jaw part series PL M1 are in connection with the second transfer device 30. In this embodiment, the second storage TV 1 , TV 2 is partly placed in connection with the transfer device 30, whereby the part REI1 of the non-functional ET jaw parts of the second set form extensions to the edge pieces RK 1 , RK 2 at the outer edges of the bending jaws (cf. Fig. 4). The second transfer device 30 comprises two transfer units 31a, 31b placed in horizontal conduits 32a, 32b of the bending jaws in the longitudinal direction in the frame 1 of the bending machine, these being placed at both sides of the first transfer device 16 in front of the frame 1 and above the bending jaws. The jaw part series PL M1 formed by jaw parts of the second set are both supported by the first gripping means 33 in the transfer units 31a, 31b. As shown in Fig. 9b, the transfer units are moved against the edge pieces RK 1 , RK 2 in the horizontal conduits 32a, 32b. As shown particularly in Fig. 9c, after releasing the lockings (to be described below), the second gripping means 34 of both transfer units 31a, 31b grip the edge pieces RK 1 , RK 2 respectively, whereby particularly in connection with the gripping movement of the gripping means (arrow E1 in Fig. 9c), at least part of the locking of the edge pieces RK 1 , RK 2 is released along the horizontal conduit 37. After this, the frame 35 of the transfer unit is moved, supported by the horizontal conduit 37 therein, whose longitudinal direction is perpendicular to the longitudinal direction of the bending jaws, away from the bending jaws (arrow P1 in Fig. 9d); whereby a rotating device 36a, placed in connection with the transfer units 31a, 31b and effective between the frame 35 of the transfer unit and the rotational frame 36, is used for revolving the rotational frame 36, with the first and second gripping means 33, 34 placed therein, 180° around the vertical direction. Thus said jaw part series PL M1 is placed in the opening left by the respective edge piece RK 1 , RK 2 . According to Fig. 9e, the transfer unit 31a, 31b moves next the edge piece RK 1 , RK 2 of the jaw part series PL M1 to the previous location (arrow E2 in Fig. 9e). According to Fig. 9f, the transfer units 31a, 31b are moved along the horizontal conduit 37 away from the bending jaws, supporting the edge piece RK 1 , RK 2 (arrow P2 in Fig. 9f). Further, both transfer units 31a, 31b are moved, as shown in Fig. 9g, to a new location of the edge pieces RK 1 , RK 2 , and the steps shown in Figs. 9h-k are carried out, substantially corresponding to the removal of the edge piece RK 1 , RK 2 described above, with the exception of removing now the jaw part series PL M2 , whose width corresponds to at least the width of the edge piece RK 1 , RK 2 , from said position. Thus, after revolution of the rotating frame 36 by the transfer units 31a, 31b in the outer position, the edge pieces RK 1 , RK 2 can be placed in position, as shown in Fig. 9j, and the transfer units 31a, 31b can be transferred along the horizontal conduits to the ends of the bending jaws. After returning the jaw part R 1n of the first set to the location S, moving the transfer units 31a, 31b along the horizontal conduits 32a, 32b to the second storage TV 1 , TV 2 , and clamping the jaw parts R 2k of the second set according to the new adjustment, the bending programme can be carried out further according to Fig. 91. Consequently, the number of non-operational jaw parts of the second set as extensions of the edge pieces RK 1 , RK 2 is changed REI1 → REI2 and the number of operational jaw parts of the second set R 2i → R 2k (Fig. 9a → Fig. 91). The clamping of the bending jaws in its longitudinal direction is carried out by directing the compression to the outermost jaw part of the non-operational jaw parts REI2 of the second set (cf. Fig. 13). Fig. 10 shows another embodiment of exchanging the jaw parts R 2i of the second set. Thus the transfer units 31a, 31b are empty, the bending jaws carrying out bending. All the non-operational jaw parts REI1 of the second set are placed at the side of the edge pieces RK 1 , RK 2 , as extensions of the same. Thus, upon beginning the exchange, after the necessary releasing of lockings and moving of the jaw parts of the second set, the transfer units 31a, 31b in the exchange position VA2 receive the jaw part series PL M1 from the non-operational jaw parts REI1 into the first gripping means. After a 180° revolution of the rotational frame 36, the transfer units 31a, 31b are moved against the edge pieces RK 1 , RK 2 , whereby the exchange is carried out as described in connection with Fig. 9 and shown in Figs. 10c-f, the jaw part series PL M1 remaining at the locations of the removed edge pieces RK 1 , RK 2 . The edge pieces RK 1 , RK 2 are then placed in a new position as described in connection with Fig. 9 and shown in Figs. 9g-k. Finally, the transfer units 31a, 31b are moved at the ends of the bending jaws, the jaw part series PL M2 are placed as extensions of the bending jaws, and the bending jaws is clamped. The second storage TV 1 , TV 2 is thus the same as the location REI2 of the non-operational jaws parts of the second set. This solution gives the advantage that all jaw parts of the second set are clamped in connection with the bending jaws. The reference numerals and other markings in Fig. 10 correspond to those in Fig. 9. Fig. 11 shows, in steps a to n, a third embodiment of exchanging the jaw parts of the second set, particularly for use in connection with reducing the operational width. The transfer units 31a, 31b are empty at the beginning, and they are moved against the edge pieces RK 1 , RK 2 , respectively; the respective edge pieces are then removed from their previous locations by steps shown in Figs. 11a-e, whereby openings AU are formed. The transfer units 31a, 31b are moved in the new locations of the edge pieces RK 1 , RK 2 , respectively (Fig. 11f), and the jaw part series PL M1 at the respective location is gripped and replaced by the edge piece RK 1 , RK 2 by steps shown in Figs. 11g-j. After this, by steps shown in Figs. 11k-n, said jaw part series PL M1 is moved to the respective end of the bending jaws to form an extension to the operational part of the bending jaws, and the jaw parts are moved towards the center and the bending jaws are clamped in their longitudinal direction, whereby the opening AU formed in the step of Fig. 11f is filled in. It should be noted that the embodiment of Fig. 11 is bas ed on the fact that the jaw parts in the operational position T (Fig. 4) are not moved to any particular exchange position (VA1, VA2) according to Figs. 9 and 10 but the longitudinal locking of the bending jaws is released at the beginning (cf. Fig. 13). Fig. 12 shows, in steps a to o, a fourth embodiment of exchanging jaw parts of the second set, particularly in connection with increasing the operational width. The basic idea is substantially the same as that shown in Fig. 11, with the exception that at the step shown in Fig. 9f, actuators 49a, 49b (described more closely in connection with Fig. 13) are used for moving the jaw parts of the second set, which at the preceding stage were in the non-operational position in the second storage TV 1 , TV 2 (sets REI1), towards the center part KO for filling in the opening AU left by the edge pieces RK 1 , RK 2 by the steps shown in Figs. 12a-e. The steps shown in Figs. 12g-o correspond to those shown in Figs. 11f-n. Consequently, the embodiments of Figs. 11 and 12 are characterized by not carrying out transfers to the exchange positions (VA1 and VA2). This is particularly advantageous when jaw parts of only the second set are exchanged, whereby an exchange of the jaw part of the first set, which is possible simultaneously, is not carried out. The locking in the longitudinal direction and the transfers of the jaw parts of the second set are carried out by the actuators 49a and 49b. With reference to Fig. 13 showing the special structures of the bending jaws for carrying out clamping operations in a schematic view seen in a direction perpendicular to the longitudinal direction of the bending jaws, it can be stated that the jaw part R 1n elected from the first set R 1 is arranged to be placed in a central part KO. The central part KO consists mainly of two locking pieces 40a, 40b preferably with an L form when seen in the direction perpendicular to the longitudinal axis of the bending jaws. The locking pieces are placed against each other so that the jaw part R 1n selected from the first set is placed between the end faces 42a, 42b of the base parts 41a, 41b of the L forms placed against each other. Thus the back surfaces 43a, 43b of the vertical parts 44a, 44b of the L forms extend towards the jaw parts aR 2i , bR 2i of the second set, being supported by said jaw parts and/or the edge pieces RK 1 , RK 2 . The bending jaws are supported in relation to the frame 1 of the bending machine against the conduits 45 in the longitudinal direction of the bending jaws. The frame part 46a, 46b of the bending jaws consists of two parts. In connection with each frame part 46a, 46b and between the bending frame 1, actuators 47a, 47b are provided for moving the two bending jaw parts 48a, 48b thus formed in relation with the frame 1 in the longitudinal direction of the bending jaws either towards the edge part R 1n selected from the first set or in opposite directions away from it. Thus each bending jaw part 48a, 48b consists firstly of one locking piece (either 48a or 48b) of the central part KO, secondly of half of the jaw parts of the second set R 2 (i.e. either the combination aR 2i and aREI or bR 2i and bREI), and thirdly of one edge piece (either RK 1 or RK 2 ). The actuators 47a, 47b are arranged to carry out a movement in the longitudinal direction of the bending jaws. The actuators 47a, 47b can be cylinder-piston-arrangements driven by a pressurized medium, whereby the piston is fixed to the frame part 46a, 46b and the cylinder preferably to the frame 1. The length of movement of the actuators 47a, 47b in the longitudinal direction of the bending jaws is elected so that, firstly, the bending jaws can be placed in the exchange position VA2 of the jaw parts of the second set; and secondly, the length of movement is sufficient for clamping the jaw part, particularly the narrowest jaw part, of the first set that is to be placed in connection with the central part KO between the end faces 42a, 42b of the locking pieces and further for bringing the end faces 42a, 42b substantially against each other for the purpose of narrowing the blade width temporarily when removing the bending jaws upwards between the edge bendings of the sheet. Particularly the exchange position VA2 for jaw parts of the second set is arranged so that the widest jaw part of the first set R 1 can be placed between the end faces 42a, 42b of the locking parts 40a, 40b, the jaw parts of the second set being placed in the exchange position VA2. In connection with the support device 22, there is an actuator 22a for moving the jaw part R 1n of the first set in the vertical direction. The actuator 22a is a cylinder-piston arrangement driven by a pressurized medium, the piston being fixed to the support device 22 and the cylinder to the frame 1. The locking parts 40a, 40b of the central part KO are fixed at the top of the vertical parts 44a, 44b to the frame parts 46a, 46b of the bending jaws, respectively, against opposite ends of said frame parts. The locking parts 40a, 40b are directed downwards at the ends of the frame parts, from the bottom surface thereof, so that the end surfaces 42a, 42b at the lower part thereof are directed against each other. The locking parts 40a, 40b in connection with the central part KO can, as distinct from the L form shown in Fig. 13, also be e.g. rectangular, whereby the vertical end and back surfaces of the same are also substantially equal in size. Also other cross-sectional forms are feasible. Further, the bending jaw parts 48a, 48b comprise each an actuator 49a, 49b. The purpose of these actuators is to lock the combination, which is in connection with the respective frame part 46a, 46b and comprises firstly the operational jaw parts of the second set (either aR 2i or bR 2i ), secondly one edge piece (either RK 1 or RK 2 ), and thirdly the non-operational jaw parts of the second set (either aREI or bREI) placed outside the edge pieces as extensions of them, by a compressing effect directed by the actuators 49a, 49b between the buffer 50a, 50b of the respective actuator 49a, 49b and the back surfaces 42a, 42b of the locking pieces 40a, 40b. For the purpose of moving and locking the bending jaws in the longitudinal direction as described above, both frame parts 46a, 46b of the bending jaws are provided with a conduit 51a, 51b, e.g. a protruding part, arranged on the bottom surface of the respective frame part 46a, 46b in the longitudinal direction of said frame part. Both the jaw parts of the second set and the edge pieces are provided with a counterpart, e.g. a grooving, placed in said conduit 51a, 51b. Also, between the conduits 51a, 51b and their counterparts, lockings are provided, as will be described below in connection with Figs. 15 and 16, on one hand for arresting the jaw parts R 2 of the second set and the edge pieces RK 1 , RK 2 in connection with the respective bending jaw part 48a, 48b and on the other hand for locking them in connection with said bending jaw part 48a, 48b. With reference to Fig. 14, the jaw part R 1n of the first set is fixed to the support device 22, arranged in the above-described manner to be movable in the vertical direction by the actuator 22a (Fig. 13). The jaw part R 1n is provided with a dovetail groove 52 in the longitudinal direction of the bending jaws, and the support device 22 with a dovetail projection 53 in a corresponding manner. In connection with the support device 22, there is a locking piece 58 arranged to be movable in relation to the support device 22, the end part of the locking piece 58 forming a first apex 54 of the dovetail projection 53 and the second apex 55 being stationary in relation to the support device 22. The oblique apices 54 and 55 are placed in oblique recesses 56, 57 at the edges of the dovetail groove 52. The locking piece 58 is articulated with a joint 59 to be pivotable in the vertical plane in connection with the support device 22. Further, the locking piece 58 is connected at its center to a locking actuator 60, whose structure corresponds substantially to that shown in Fig. 15 and to be described further below. The locking actuator 60 is placed inside the support device, and it is driven by a pressurized medium. The gripping means 17, 20 (Figs. 7 and 8), placed in connection with the first transfer device 16, correspond in their structure to those shown in Figs. 15 and 16, whereby these are provided preferably two means side by side. Their counterpart, such as a pair of adjacent holes, is placed at a location 61, corresponding in structure to the counterpart 69 shown in Figs. 15 and 16. The jaw part R 1n of the first set is released substantially in the same way as shown in Figs. 15 and 16, whereby the first apex 54 is moved by the gripping means 17 (or 20) from the locking position to the point K shown by broken lines, preferably when coupled with the counterpart at the point 61 or by a locking actuator 60 separate from said coupling. Thus the jaw part R 1n , partly supported by the first transfer device 16, is first moved horizontally to the left in Fig. 14 (arrow I) for releasing the vertical locking between the parts 55 and 57, whereby the first apex, having moved to the point K, does not prevent this movement, and after this downwards in Fig. 14 (arrow II), whereby the jaw part R 1n is released to be moved to the right in Fig. 14, from behind the apex 55. The gripping means 17, 20 of the transfer device 16 can be equipped with protruding means or the like, which, upon coupling said gripping means 17, 20 and the jaw- part R 1n (cf. Fig. 16), release the first apex 54 from the groove 56 to the position K. Figs. 15 and 16 show-the locking of jaw parts R 2 of the second set and the method of releasing it, primarily the locking and releasing of the jaw part series indicated above with the reference letters PL M , PL M1 and PL M2 as well as of the edge pieces RK 1 , RK 2 , carried out by the second transfer device 30 (transfer units 31a, 31b and the adjacent gripping means 33, 34 in connection with the same). The conduits 51a, 51b in connection with the frame parts 46a, 46b correspond in their cross-section and general construction to that described in connection with Fig. 14, and the corresponding elements are indicated with reference numerals corresponding to those in Fig. 14. The locking piece 58 is substantially a moulding piece of equal length with the frame parts 46a, 46b, equipped with locking actuators 60 at certain intervals in the longitudinal direction of the bending jaws. In the present embodiment, the locking piece 58 is moved by the joint effect of the locking actuators 60 driven by a pressurized medium to the left in Fig. 15, opening the locking between the apex 54 and the recess 56. This takes place after the gripping means 33, 34 has moved to the position shown in Fig. 16, in connection with the jaw part R 2i . The gripping means has an interface VP that releases the vertical locking of a rocking arm 62 in the jaw part R 1n , i.e. removes a locking stud 63 at the first end 62a of said rocking arm from a horizontal groove 64 in connection with the frame parts 46a, 46b above the jaw part. The rocking arm 62 is articulated with a joint 65 to a stud 66 in the jaw part R 2i . At the other end of the rocking arm 62, there is a spring means 67 coupled with the jaw part R 2i that returns the rocking arm 62 to the locking position upon removal of the gripping means 33, 34 from the connection of the jaw part R 2i when the jaw part R 2i is removed from said transfer unit 31a, 31b. In the present embodiment, the gripping means 33, 34 is a so-called expanding mandrel 68 with an outer bush 68a with longitudinal grooves, a pin part 68b being arranged to be movable inside the outer bush 68 in its longitudinal direction. The jaw part R 2i , on the other hand, is provided with a hole 69 functioning as a receiving means. The pin part 68b being inside the outer bush 68a in its front position shown in Fig. 16, a friction joint is formed between the outer surface of the radially expanding bush 68a and the inner surface of the hole 69, coupling the jaw part R 2i and the transfer unit 31a, 31b together and coming loose when the pin part 68b is substantially outside the bush 68a. The locking actuator 60 comprises a piston rod 70 and a piston 71. The piston rod 70 penetrates a sealing part 72 and is coupled with the locking piece 58. The frame parts 46a, 46b are provided with longitudinal boreholes 73 and 74 which are connected at opposite sides of the piston 71 for feeding pressurized medium to the cylinder space 75 for moving the piston 71 in the cylinder space 75 and thus for moving the locking piece 58. As shown in Fig. 15, the locking of the locking piece 58 is secured by a pressure spring 76, whereby pressure disturbances do not release the locking between the parts 54 and 56. It should be noted that there is a sufficient number of gripping means 33, 34 side by side at certain intervals in connection with the transfer units 31a, 31b, whereby it is possible simultaneously to grip and release as well as to install and lock the said jaw part series PL M , PL M1 , PL M2 . In connection with exchanging the edge pieces RK 1 , RK 2 , two or more of these gripping means are used, whereby the edge pieces are equipped with counterparts for the holes 69. With reference to the description above, e.g. the exchange of the jaw part series PL M is carried out so that firstly a) a series of gripping means 33, 34, are placed side by side in the transfer unit 31a, 31b in connection with the counterparts 69 of the adjacent jaw parts R 2i , i.e. the jaw part series PL M , PL M1 , PL M2 , b) the gripping means 33, 34 and said counterparts 69 are locked e.g. by means of a radially expanding mandrel 68, c) the safety locking between the jaw part series PL M , PL M1 , PL M2 and the frame parts 46a, 46b is released, particularly upon placing the gripping means 33, 34 in connection with the counterparts 69, preferably by releasing the locking arm 62 from the groove 64 of the frame parts 46a, 46b, d) the locking of conduits 51a, 51b and 52 in the frame parts 46a, 46b on one hand and in the jaw part series PL M , PL M1 , PL M2 on the other hand is released, preferably by moving the movable locking piece 58 of the conduits 51a, 51b in relation to the frame parts 46a, 46b, for releasing the first locking of the first part 54, 56 substantially in the vertical and horizontal directions, e) said jaw part series PL M , PL M1 , PL M2 is moved by said transfer unit 31a, 31b in a first direction, particularly in the horizontal direction (arrow I), and then in a second direction, particularly in the vertical direction (arrow II) downwards for releasing the second locking of the second part 55, 56 substantially in the vertical and horizontal directions, and f) after the steps a to e, the exchange steps described above in connection with Figs. 9-12 are carried out. It should be noted that the steps a to f described above are substantially applicable also for the exchange of the edge pieces RK 1 , RK 2 .

Claims: Apparatus for adjusting the width of the bending jaws of a bending machine, wherein the bending jaws (2b) in the frame (1) of the apparatus comprise two sets of jaw parts which, for adjusting the width, are arranged to be transferred and/or exchanged by transfer devices (16, 30) from an operational point (T) to a non-operational point (ET), these points being in connection with the bending machine and vice versa, respectively, wherein the first set (R 1 ) is placed in the middle of the bending jaws and the second set (R 2 ) is placed at both sides of the first set, wherein the edges of the bending jaws are provided with edge pieces (RK 1 , RK 2 ) which are part of the bending jaws and define the total width of the bending jaws, wherein, for determining the width (L) of the bending jaws, the first set and the second set (R 1 , R 2 ) are formed in the following manner: the first set (R 1 ) is elected to form a group of jaw parts for so-called fine adjustment, the second set (R 2 ) is elected to form a group of jaw parts with identical width for so-called coarse adjustment, wherein the width of the bending jaws required at a time is elected according to the equation L = R 1n + N * R 2i + C wherein L = the width of the bending jaws, R 1n = the width of the jaw part (n = 1...M) elected from the first set (R 1 ), N = the width of the jaw parts of the second set (R 2 ), i.e. a constant, R 2i = the number (i = 0...k) of jaw parts of the second set (R 2 ) at the operational point (T) of the bending jaws, and C = a constant, comprising the parts with a constant width included in the total width of the bending jaws, wherein the apparatus comprises further a first storage (EV) for non-operational jaw parts of the first set (R 1 ), a first transfer device (16) for exchanging the jaw parts of the first set (R 1 ) from the storage (EV) to the operational position (T) in connection with the bending jaws, a second storage (TV) for non-operational jaw parts of the second set (R 2 ), and a second transfer device (30) for exchanging edge pieces (RK 1 , RK 2 ) and jaw parts of the second set (R 2 ) to the location defined by the desired width of the bending jaws and for transferring the non-operational jaw parts of the second set (R 2 ) to the second storage (TV), characterized in that the first set (R 1 ) is elected to form a group of jaw parts of different widths for so-called fine adjustment, one at a time (R 1n ) being at the operational point (T) of the bending jaws, and the first transfer device (16) comprises a transfer arm (19) or the like arranged to be pivotable at its first end in the vertical plane, wherein the second end of the transfer arm (19) is equipped with a rotary frame (21) comprising a first gripping means (17), for gripping a jaw part (R 1m ) a second gripping means (20), for gripping another jaw part (R 1n ), and a rotary device (21a) for pivoting the rotary frame (21) together with the gripping means (17, 20) therein substantially around the longitudinal axis of the transfer arm (19) or the like. Apparatus according to claim 1, characterized in that the first storage (EV) is placed above the bending jaws in the frame (1) of the bending machine, and that the first transfer device (16) is arranged to operate substantially in the vertical direction, fixed to the frame (1) of the bending apparatus, in connection with the exchange of the jaw parts of the first set (R 1 ). Apparatus according to claim 1 or 2, characterized in that the first storage (EV) is arranged to move in relation to the frame (1) of the bending machine for bringing the jaw part of the first set (R 1 ) which is to be exchanged, to the gripping position of the first transfer device (16). Apparatus according to any one of claims 1 to 3, characterized in that the second set (R 2 ) is elected to form a group of jaw parts and of edge pieces (RK 1 , RK 2 ) and said total width of the bending jaws comprises at least the total width (C R ) of the edge pieces (RK 1 , RK 2 ) and the total width (C L ) of the locking parts (LO) between the first and second sets. Apparatus according to claim 1, characterized in that the second storage (TV) is placed outside the edge pieces (RK 1 , RK 2 ) of the bending jaws in the longitudinal direction of the bending jaws to form a two-part second storage (TV 1 , TV 2 ). Apparatus according to claim 1 or 5, characterized in that at least part of the second storage (TV) is placed in connection with the second transfer device (30). Apparatus according to claim 1, characterized in that the second transfer device (30) comprises two transfer units (31a, 31b) which are placed in horizontal guides (32a, 32b) in the frame (1) of the bending machine, preferably placed at both sides of the first transfer device (16), and that the transfer units (31a, 31b) are provided with rotary frames (36) in connection with their frame (35), comprising: first gripping means (33), second gripping means (34), and a rotary device (36a) for pivoting said rotary frame (36) together with the gripping means (33, 34) therein substantially around a vertical axis. Apparatus according to claim 1, characterized in that the jaw part (R 1n ) elected from the first set (R 1 ) is arranged to be placed in a center part (KO) comprising two locking pieces (40a, 40b) facing each other so that the jaw part (R 1n ) elected from the first set (R 1 ) is placed between the first surfaces (42a, 42b) of the locking piece (40a, 40b), wherein the second surfaces (43a, 43b) of the locking piece (40a, 40b) directed towards the jaw parts of the second set (R 2 ) are supported by said jaw parts (R 2 ) and/or the edge pieces (RK 1 , RK 2 ). Apparatus according to claim 1 or 8, characterized in that the jaw part (R 1n ) elected from the first set (R 1 ) is arranged to be placed in a center part (KO) comprising two locking pieces (40a, 40b) with substantially an L-form or the like seen in a direction perpendicular to the longitudinal direction of the bending jaws, said locking pieces being placed against each other so that the elected jaw part (R 1n ) of the first set is placed between the faces (42a, 42b) of the opposite flanges (41a, 41b) of the L-forms, wherein the rear surfaces (43a, 43b) of the vertical parts (44a, 44b) of the L-forms facing the jaw parts of the second set (R 2 ) are supported against said jaw parts (R 2 ) and/or the edge pieces (RK 1 , RK 2 ). Apparatus according to claim 1 or 8 or 9, characterized in that the bending jaws are supported against the frame (1) of the bending machine by the guides (45) placed in the longitudinal direction of the bending jaws, and that actuators (47a, 47b) or the like are arranged between the frame part (46a, 46b) of the bending jaws and the frame (1) of the bending machine for transferring two bending jaw parts (48a, 48b), each comprising one of the two locking pieces (40a, 40b) of the center part (KO), at least half of those jaw parts (aR 2i , bR 2i ) of the second set (R 2 ) which are at the operational point (T), and one of the two edge pieces (RK 1 , RK 2 ), in opposite directions in the horizontal direction particularly for releasing the jaw part of the first set (R 1 ), particularly for exchanging the jaw part of the first set (R 2 ) and locking it at the operational point (T) of the bending jaws in the longitudinal direction of the bending jaws and/or for transferring the jaw parts of the second set (R 2 ) towards the sides, e.g. to the exchange position (VA2). Apparatus according to claim 1 or 10, characterized in that each bending jaw part (48a, 48b) comprises an actuator (49a, 49b) or the like for locking the jaw parts of the second set (R 2 ) between the locking piece (40a, 40b) of the center part (KO) and the edge piece (RK 1 , RK 2 ), for releasing said locking, and/or for transferring the jaw parts of the second set (R 2 ) in the longitudinal direction of the bending jaws, the operational direction of the actuators (49a, 49b) being substantially the longitudinal direction of the bending jaws. Apparatus according to any of claims 1, 10 or 11, characterized in that the actuators (49a, 49b) are arranged to direct the pressing effect to at least some of the jaw parts (aREI, bREI) of the second set (R 2 ) in connection with the second storage (TV), forming extensions of the edge pieces (RK 1 , RK 2 ). Apparatus according to any of claims 1, 10, 11, or 12, characterized in that the actuators (49a, 49b) are placed to be effective between the frame part (46a, 46b) of the bending jaws and the outermost jaw part of the second set (R 2 ) and/or the edge piece (RK 1 , RK 2 ). Apparatus according to claim 1 or 7, characterized in that the transfer units (31a, 31b) are arranged to operate as part of the second storage (TV) so that some of the jaw parts of the second group (R 2 ) are placed at a non-operational position (ET) to be supported by the gripping means (33 or 34). Apparatus according to any of claims 1, 7, or 14, characterized in that the gripping means (17, 23; 33, 34) comprise each a protruding part (68), particularly a radially expanding mandrel (68), arranged to be inserted in a counterpart (69), such as a hole, in connection with the jaw part of the first set (R 1 ), the jaw part of the second set (R 2 ), preferably the jaw part series (PL M ) and/or the edge pieces (RK 1 , RK 2 ). Apparatus according to any of claims 1, 7, 14, or 15, characterized in that between the removable part (R 1n , R 2i , PL M , RK 1 , RK 2 ) and the frame (1) or a part of the same, preferably the frame part (46a, 46b) of the bending jaws, a safety locking (62) is arranged, which is preferably arranged to be opened in connection with coupling of the transfer device (16, 30) by a movement of the transfer device (16, 30). Apparatus according to any of claims 1, 7, 10, 14, 15, or 16, characterized in that the locking of the jaw parts of the second set (R 2 ) and the edge pieces (RK 1 , RK 2 ) in the frame part (46a, 46b) of the bending jaws is arranged to comprise two parts, that the frame part (46a, 46b) is provided with a locking actuator series (60) in the longitudinal direction of the bending jaws, that the locking actuator series (60) is connected with the first part (54, 58) of the first locking which extends substantially to the length of said frame part (46a, 46b) in the longitudinal direction of the bending jaws, that the first part (54, 58) of the first locking is arranged to be movable in a direction perpendicular to the longitudinal direction of the frame part (46a, 46b) for opening the first locking (54, 58) between the locking part (R 2i ) of the second set, particularly the jaw part series (PL M ), and/or the edge piece (RK 1 , RK 2 ) and the frame part (46a, 46b), and that the second locking (55, 57) is arranged to be released by a series of movements in relation to the frame (1) of the transfer device (16, 30). Method for adjusting the width of the bending jaws of a bending machine to be used with an apparatus according to any one of claims 1 to 17, wherein the bending jaws comprise two sets of jaw parts which are, for adjusting the width of the bending jaws, transferred and/or exchanged from an operational point (T) to a non-operational point (ET), these points being preferably in connection with the bending machine and vice versa, respectively, wherein the first set (R 1 ) is placed in the middle of the bending jaws and the second set (R 2 ) is placed at both sides of the first set, wherein the edges of the bending jaws are provided with edge pieces (RK 1 , RK 2 ) which are part of the bending jaws and define the total width of the bending jaws, wherein the total width (L) of the bending jaws is defined in the following manner: the first set (R 1 ) is elected to form a group of jaw parts for so-called fine adjustment, the second set (R 2 ) is elected to form a group of jaw parts with identical width and to be separate from the edge pieces (RK 1 , RK 2 ) for so-called coarse adjustment, wherein the width of the bending jaws required at a time is elected according to the equation L = R 1n + N * R 2i + C wherein L = the width of the bending jaws, R 1n = the width of the jaw part (n = 0...M) elected from the first set (R 1 ), N = the width of the jaw parts of the second set (R 2 ), i.e. a constant, R 2i = the number (i = 0...k) of jaw parts of the second set (R 2 ) at the operational point (T) of the bending jaws, and C = a constant, comprising the parts with a constant width included in the total width of the bending jaws, characterized in that the first set (R 1 ) is elected to form a group of jaw parts of different widths, one at a time (R 1n ) being at the operational point of the bending jaws. Method according to claim 18, characterized in that the number of jaw parts in the second set (R 2 ) is chosen to be even and as many jaw parts of the second set (R 2 ) are placed on both sides of the jaw part (R 1n ) chosen from the first set (R 1 ) in order to achieve a symmetrical bending jaw structure, wherein the index i in the term R 2i is i = 0, 2, 4, 6...k, where k is an even number. Method according to claim 18 or 19, characterized in that the number of jaw parts in the first set (R 1 ) is chosen in the following manner: M = N LE or M = 2 * N LE wherein M = number of jaw parts in the first set (R 1 ), N or 2*N = width of eachjaw part or two jaw parts in the second set (R 2 ), and LE = constant difference in the width of subsequent jaw parts, e.g. R 1,n and R 1,n+1 , in a series of jaw parts of the first set (R 1 ). Method according to any of claims 18 to 20 above, characterized in that the width of the jaw parts of the first set (R 1 ) is elected in the following manner: KL n = C M + K (k) * LE wherein KL n = width of a certain jaw part R 1,n of the first set (R 1 ), wherein n receives a value 1...M, where M is the number of jaw parts, C M = a constant, i.e. the basic width of jaw parts in the first set, K (k) = a coefficient which receives in the formula a value 0, 1, 2 up to M-1, where M is the number of jaw parts, and LE = constant difference in the width of subsequent jaw parts, e.g. R 1,n and R 1,n+1 , in a series of jaw parts of the first set (R 1 ), wherein the constant C M is elected according to the temporary need of narrowing the width of the bending jaws, particularly for lifting the bending jaws. Method according to any of claims 18 to 21, characterized in that a first storage (EV) for jaw parts of the first set (R 1 ) is placed in connection with the bending machine, and a first transfer device (16), effective substantially between the first storage (EV) and the location (S) of the jaw part (R 1n ) of the first set (R 1 ) at the operational point in the bending jaws, is placed in connection with the bending machine. Method according to any of claims 18 to 22, characterized in that for changing the jaw part (R 1n ) of the first set, the following steps are taken: the locking of the jaw part (R 1n ) of the first set at the location (S) is released in the longitudinal direction, a transfer device (16) is used for gripping at the jaw part (R 1m ) of the first set being in the first storage (EV) and to be placed next at the location (S), the transfer device (16) together with the jaw part (R 1m ) of the first set to be placed at the location (S) are transferred in connection with the jaw part (R 1n ) of the first set to be removed, the transfer device (16) is used for gripping at the jaw part (R 1n ) of the first set and to be removed from the location (S), and it is removed to the support of the transfer device (16), the transfer device (16) is used to carry out an exchange movement for directing the jaw parts (R 1n , R 1m ) so that the locations of the jaw parts (R 1n , R 1m ) are reversed, the jaw part (R 1m ) of the first set to be placed at the location (S) is transferred to the location (S), the jaw part (R 1m ) of the first set to be placed at the location (S) is locked in connection with the bending jaws, and the jaw part (R 1n ) of the first set to be removed is placed by the transfer device (16) into the first storage (EV). Method according to any of claims 18 to 23, characterized in that for changing the jaw part (R 1n ) of the first set, the following steps are taken: the locking of the jaw part (R 1n ) of the first set in the location (S) is released in the longitudinal direction of the bending jaws, the jaw part (R 1n ) to be removed from the location (S) is transferred to the exchange position (VA1), the transfer device (16) is used for grabbing the jaw part (R 1m ) of the first set which is in the first storage (EV) and is to be placed next to the location (S), the first transfer device (16) and the jaw part (R 1m ) of the first set to be placed to the location (S) are placed together in connection with the exchange position (VA1), the transfer device (16) is used for grabbing the jaw part (R 1n ) of the first set being in the exchange position (VA1) and to be removed from the location (S), and it is released to the support of the transfer device (16), the exchange movement is carried out by the transfer device (16) in order to direct the jaw parts (R 1n , R 1m ) so that the position of the jaw parts (R 1n , R 1m ) is reversed, the jaw part (R 1m ) of the first set to be placed at the location (S) is transferred to the location (S), and it is locked in connection with the bending jaws, the jaw part (R 1m ) of the first set to be placed in the location (S) is transferred to the location (S), the jaw part (R 1m ) of the first set is locked in the longitudinal direction of the bending jaws, and the jaw part (R 1n ) of the first set to be removed is transferred to the first storage (EV) by the transfer device (16). Method according to any of claims 18 to 24, characterized in that the jaw parts of the second set (R 2 ) which are at the operational point (T) at a time, are exchanged in the following manner: the locking of at least those jaw parts of the second set (R 2 ) which are at the operational point (T) is released in the longitudinal direction of the bending jaws, the edge pieces (RK 1 , RK 2 ) are released and transferred from the operational point (T) to the exchange position, separate from the operational jaw parts (R 2i ) of the second set, by using a second transfer device (30), the second transfer device (30) is transferred to the new location of the edge pieces (RK 1 , RK 2 ), for achieving a new operational location for the edge pieces (RK 1 , RK 2 ), the series (PL M ) of jaw parts of the second set (R 2 ) is removed by the second transfer device (30), the edge pieces (RK 1 , RK 2 ) are placed at the new operational location of the removed series (PL M ), and the edge pieces (RK 1 , RK 2 ) and at least those jaw parts (R 21 ) of the second set which are at the operational point (T) are locked in the longitudinal direction of the bending jaws. Method according to any of claims 18 to 25, characterized in that those jaw parts of the second set (R 2 ) which are at the operational point (T) of the bending jaws at a time, are exchanged in the following manner: at least those jaw parts of the second set (R 2 ) which are at the operational point (T) are exchanged to the exchange position (VA2), the locking of at least those jaw parts of the second set (R 2 ) which are at the operational point (T) is released in the longitudinal direction, the edge pieces (RK 1 , RK 2 ) are released and transferred from the operational location to the exchange position, separate from the operational jaw parts of the second set (R 2i ) by using the second transfer device (30), the series (PL M ) of jaw parts of the second set (R 2 ) is placed at the previous location of the edge pieces (RK 1 , RK 2 ), the second transfer device (30) is transferred to the new location of the edge pieces (RK 1 , RK 2 ), for achieving a new operational location for the edge pieces (RK 1 , RK 2 ), the series (PL M ) of jaw parts of the second set (R2) is released by the second transfer device (30), the edge pieces (RK 1 , RK 2 ) are placed at a new location, the location of the removed series (PL M ), the jaw parts of the second set are transferred from the exchange position (VA2) to the operational point (T), and the edge pieces (RK 1 , RK 2 ) and at least those jaw parts (R 2i ) of the second set which are at the operational point (T) are locked in the longitudinal direction of the bending jaws. Method according to claim 25 or 26, characterized in that the series (PL M ) of removed jaw parts of the second set (R 2 ) are stored in connection with the second transfer device (30) for the time between the exchanges. Method according to claim 25 or 26, characterized in that the series (PL M ) of removed jaw parts of the second set (R 2 ) are placed in connection with those jaw parts of the second set (R 2 ) which form an extension to the edge pieces (RK 1 , RK 2 ) at the non-operational position (ET). Method according to any of claims 23 to 26, characterized in that the bending jaws are locked in the longitudinal direction by the second transfer device (30) with two transfer units (31a, 31b), which transfer units (31a, 31b) are placed at both ends of the jaw parts of the second set (R 2 ). Method according to any of claims 25 to 29, characterized in that the openings (AU) left in the bending jaws by the removed edge pieces (RK 1 , RK 2 ) are filled in by transferring the non-operational edge pieces towards the center part (KO). Method according to any of claims 25 to 29, characterized in that the total width (C k ) of the edge piece (RK 1 , RK 2 ) in the longitudinal direction of the bending jaws is elected to be substantially equal or less than the product of the width (N) and number (LM) of jaw parts of the second set, wherein between the number (LM) and width (N) of the jaw parts of the series (PL K ) to be removed and the total width (C K ) of the edge pieces (RK 1 , RK 2 ), there is an equation: LM * N ≥ C K Method according to any of claims 18 to 31, characterized in that for releasing jaw parts of the first set (R 1 ), jaw parts of the second set (R 2 ), particularly the jaw part series (PL M ) and/or the edge pieces (RK 1 , RK 2 ) from the bending jaws, the following steps are taken: for achieving locking, the gripping means (17, 20; 33, 34) of the first or second transfer means (16, 30) are moved into connection with the counterpart (69) of the respective part (R 1n , R 2i , PL M , RK 1 , RK 2 ) in the bending jaws to be exchanged, if necessary, the safety locking (62) of each part (R 1n , R 2i , PL M , RK 1 , RK 2 ) to be exchanged is released, particularly in connection with the movement of transfer of the gripping means (17, 20; 33, 34), the first locking (54, 55) is opened by means of a locking actuator (60) in connection with the frame (1) or a part (22, 46a, 46b) connected to it, the second locking (55, 57) is released by a series of movements of the transfer device (16, 30) in relation to the frame (1) for bringing each part (R 1n , R 2i , PL M , RK 1 , RK 2 ) on the support of the first or second transfer device (16, 30), and the operations for fixing the parts (R 1n , R 2i , PL M , RK 1 , RK 2 ) are carried out in reverse order. Method according to any of claims 18 to 32, characterized in that for adjusting the width of the bending jaws, the exchange of jaw parts of the first set (R 1 ) and of the second set (R 2 ) is carried out substantially simultaneously if necessary.

Inventors: DE ROSSI ROBERTO, PATUZZI LUIGI, DE ROSSI, ROBERTO, PATUZZI, LUIGI
Applicants: LILLBACKA JETAIR OY
Application year: 1995
Main classification: B21D5
IPC codes: B21D5