FR2574008A1 - TWO ROLLER FOR TOLES - Google Patents

Abstract

THE INVENTION CONCERNS WORKING METALS BY DEFORMATION. THE SHEET FOLDER WHICH IS THE OBJECT OF THE INVENTION IS CHARACTERIZED IN THAT IT IS EQUIPPED WITH A TRAVERSE 33 MOUNTED IN THE UPRIGHTS 2, 3 OF THE BUILD 1 AND BEARING AT LEAST ONE WALL 34 ON WHICH IS MOUNTED A SUPPORT 35 SUPPORTING THE ROLLER FORMING 5 DURING THE BENDING PROCESS, AND DEVICES 36, 37 SERVING TO HOLD THE DEFORMING ROLLER 5 DURING THE REMOVAL OF THE BENDED BLANK 14 AND MOUNTED AT THE ENDS OF THE SAID TRAVERSE. THE BENDER IN QUESTION CAN BE USED IN PARTICULAR FOR THE MANUFACTURE OF TUBULAR PARTS USED IN THE AERONAUTICAL INDUSTRY, THE AUTOMOTIVE INDUSTRY, AS WELL AS IN CHEMICAL ENGINEERING.

Description

The present invention relates to the work of metals by deformation and has

in particular for the purpose

  two roller folding machine for sheets.

  The invention can be successfully applied, in particular, to the manufacture of tubular parts used in the aerospace industry, the automotive industry, as well as in chemical engineering, by folding metal sheets.

  In addition, the invention can be used for ob-

  folding, structural elements in the form of troughs, reflectors, etc. In structures manufactured in industry

  aeronautics and other branches of the

  mechanical tructions, a wide nomenclature of tubular parts obtained from plates made of aluminum alloys, titanium, plates of corrosion-resistant steels, have a diameter ranging from 60 to 200 mm, the ratio between the length of the piece and the diameter being greater than 10. Under the conditions of manufacture of this vast nomenclature in small series, the process currently applied for the manufacture of these parts is characterized by labor costs.

  and a large volume of the adjustment work carried out

hand-drawn.

  Good results, with regard to the precision of the folding, are obtained by the combined method of folding of the cylindrical pieces from sheets, according to which the curvature of the part is to be impressed on the part to be folded, in the state of charge. forming tool. To achieve this method of folding, it is piéférable to use a folder with two rolls for sheets. The folding of tubular pieces whose diameters are between 60 and 200 mm (taking into account the elasticity of the blank after folding) can be

  made with the aid of this folder equipped with rollers

  mants with a diameter of 30 to 150 mm.

  A two-roll folder is known for

  sheet metal, having a frame with uprights, a roll

  interchangeable water with hard surface, mechanically bonded to the uprights, and a roller provided with an elastic coating, mounted on uprights folding a blank sheet with respect to the roll forming and

  equipped with a control for its rotation and a mechanism

  radial displacement nism (patent of invention

  United States of America No. 3,371,513).

  The interchangeable roller of this known folder is constituted by a hard surface tube fitted with a certain clearance on a sleeve mounted in a symmetrical manner on two spherical bearings on an axis. One end of the axis is engaged in a hole made in a frame upright, the other end engages in a folding support whose axis of rotation is mounted hard in the opposite amount. The spherical bearings are arranged, with respect to the end faces of the bushing, so that the maximum deflection on the part in the bay and the maximum deflection on the brackets are equal in order to ensure,

  for a given load, a minimum value of

maximum.

  This design of the forming roll provided with a bushing is used when the diameter of the roll is greater than 90 mm and the ratio of its length to its diameter is less than 10. When said diameter is smaller, the roll forming the folder considered is made full and with two supports. Its rigidity is

  weak and, for this reason,

its length.

  Another disadvantage of this machine lies in the fact that it is necessary to spend a considerable amount of time to deposit the circular blank after its folding, because, for

  this, it is necessary not only to discard the coated roll-

  elasticity and stop the rotation, but, moreover,

  must move one of the supports from the forming roll.

  It follows that the known bending machine with two wheels

  One of the two types of water has the disadvantage that it does not make it possible to use forming rollers whose ratio of length to diameter is greater than 10, for the formation of

  tubular parts from alloy sheets of titanium

  tane and high-strength aluminum alloy

mechanical strength.

  o: 0 It was therefore proposed to develop a

  two-roll bending machine for folding sheets to obtain

  tubular parts from titanium, aluminum or steel-resistant steel sheets.

  corrosion of which the support device of the roller

  mant would be designed to ensure the rigidity of forming rollers whose ratio of length to diameter is greater than 10, the diameter of the roll

  forming part being 30 mm or more, which would enable

  quickly worm the finished piece.

  The problem thus solved is solved by the fact that the two-roll bending machine of the type comprising an upright frame, an interchangeable hard-surface roller mechanically bonded to the uprights, and an elastic-coated roller mounted on the uprights folding a flat blank compared to the roller forming and equipped

  a rotation control and a moving mechanism

  radial cement, is characterized, according to the invention, in that it has a crossmember mounted in the uprights of the frame and carrying at least one wall on which is mounted a support receiving the roll forming during the folding process and at the ends of which mounted devices for holding the roll during

  removal of the folded blank.

  The presence of said crosspiece with its wall allows to mount on it a sufficient number of supports to ensure the rigidity of a roll forming a diameter of 30 mm or more. The supports are made so that they can be arranged within the limits of an outline defined by the minimum inside diameter of the folded tubular piece, taking into account the elasticity. Since said wall is thin, it is possible to fold the piece in a single pass along a half-meter of the circular contour. The second pass completes the folding of the piece along the entire circular contour. The forming roll is applied against the supports under the action of the technological load created during folding. When the load is removed, the forming roll moves away from the supports under the action of its own weight and is held relative to the wall by the devices mounted at its ends. This method of mounting the roll forming on the sheet metal bender ensures a quick removal of the workpiece after bending, because it is no longer necessary to release it from the supports and the

  piece is then removed from the folder. She is moving

  simply following the generator of the roll.

  It is advantageous for the support to be executed under

  form of rollers mounted in two rows according to the gen-

  forming the roller and forming such that the maximum value of the angle between the tangents to the generatrices of the rollers at the points of contact thereof with the forming roll is at least 140. The support consisting of rollers makes it possible to make insignificant the losses due to the friction forces during the rotation of the forming roll. As is apparent from the experiments carried out, the arrangement of the rolls in two rows

  parallel ensures a stable position of the forming roll.

  The following support can be arranged

roller forming.

  The utility to realize such an assembly of the support is determined according to the load acting on him following

  its entire length, efforts, and bending of the

  forming water that act on the support. Given that

  tubular parts must satisfy conditions

  severe lengths of the end portions that are not permanently folded, a very large variety of parts are shaped, as is apparent from the experiments, under a load that requires that the support is arranged along the entire generator of the roll. It may be useful for the machine to be provided with a mechanism for moving a portion of the rollers away from the surface of the forming roll and having a jack

  hydraulic linked by a rod with pebbles. This concept

  It should be used for folding thin-walled tubular parts of relatively large diameter, when the preliminary bending is carried out with great effort and, therefore, using all the supports following the generator, the bending according to the main contour that can be executed under a small load along the length, a part of the rollers having been put out of contact with the forming roll. If the length of the released area is greater than or equal to the length of the piece to be folded, the folding can be done in a single pass, which

  raises the yield of the folding process.

  It is advantageous that each device intended to hold the forming roll comprises an axle mounted by one of its ends in the wall with the possibility of moving in the axial direction, and engaging by its other end in a bore made in the face

at the end of the forming roll.

  This embodiment of the device makes it possible to quickly remove and assemble the forming roll in the event of a change for forming another type and dimension of the tubular piece. Another advantage of this embodiment is that, if the walls

  the bore of the forming rollers are of the same thickness.

  the passage of a roll forming a certain diameter to another roll of another diameter does not

  requires no displacement of the body of the device.

  In order to reduce the time required for adjusting the bender, it is advantageous to provide a mechanism for moving the resilient-coated roller during adjustment relative to the wall during adjustment of the bender for another diameter of the bending machine. roller forming, this mechanism being kinematically linked to the radial displacement mechanism

  elastic coated roll.

  The adjustment movement mechanism

  the need for a reset to zero at each adjustment of the driving depth in the elastic-coated roller. In other words, we no longer need to carry out the operation of putting

  firstly the forming roll and the coated roll-

  elastic contact. With the aid of the adjusting movement mechanism, it is possible to determine, when changing the forming roll, even without this roll, the position of the elastic-coated roll

relative to the wall.

  It is desirable that the mechanism for

  of the elastically coated roller for adjustment is performed as a rule fixed on the frame and a flexible band kinematically bound

  to the radial displacement mechanism of the coated roll-

  The rule is graduated so that each division corresponds to the value of the radial displacement of the elastic-coated roll, and the band is graduated to display the diameter of the forming roll. This embodiment is simple from the point of view of design and makes it possible to obtain information

  clear on the depth of insertion of the roll for-

  mant in the elastic coating.

  The invention will be better understood and other purposes, details and advantages thereof will appear

  better to read the following description of

  various embodiments given solely by way of nonlimiting examples with reference to the appended drawings in which: FIG. 1 represents an overall view;

  a two-roll sheet metal folding machine according to the invention.

  tion (front view); - Figure 2 is a sectional view along II-II of Figure 1; FIG. 3 shows a roller in contact with the roll forming (partial section in FIG. 2) on an enlarged scale; FIG. 4 shows a variant of the folding machine, provided with a mechanism intended to separate part of the rollers (partial section of the folder); FIG. 5 represents an overall view of the device intended to hold the roll forming (partial section) in Figure i, on an enlarged scale); FIG. 6 is an overall view of the transfer device for positioning the elastic coated roll in cross section; FIG. 7 is a view along arrow A;

of Figure 6.

  The bending machine with two rollers forming the subject of the invention comprises a frame 1 (FIG. 1) executed in the form of a box with end faces of which are fixed uprights 2 and 3 coupled by a crosspiece 4. The folder also includes a roll forming a hard surface 6 mechanically linked to the uprights 2 and 3 so as to be able to freely rotate. Ports 7 and 8 are formed in the uprights 2 and 3 for the axis 9 on which are mounted a left flange 10 and a right flange 11, intended to allow the mounting of a roller 12 having a coating

  elastic 133with the possibility of the rotation of this roll.

  The roll 12 provided with the elastic coating 13 is intended for folding a flat blank 14 (FIG. 2) with respect to the forming roll 5 and is executed under

  shape of a metal core 15 on which are

  hardened rings 16 in elastic material, for example polyurethane. The roller 12 with elastic coating 13 is provided with a control 17 (Figure 1) for its rotation, for example, a hydraulic motor mounted on the flange 11, and a mechanism 18 effecting its radial displacement. The mechanism 18 of radial displacement is constituted by hydraulic cylinders 19 and 20 mounted with the aid of pins 21 and 22 on supports 23 and 24 integral with the frame 1. On each rod 25 and 26 of the hydraulic cylinders 19 and 20,

  is mounted an eye 27 and 28, respectively; who

  plating in a groove 29 and 30, respectively, of a flange 10 and 11, respectively, and which is connected to

  this one by an axis 31 and 32, respectively.

  According to the invention, the folder is provided with a crossbar 33 mounted on the uprights 2 and 3 of the frame 1 and carrying a wall 34 on which is mounted a support receiving the roll forming 5. The devices 36 and 37 mounted at the ends of wall 34 serve to hold the forming roll 5 during the removal of

the folded blank 14.

  The crosspiece 33 is in the form of a rigid beam at the ends of which are provided support elements 38 and 39 mounted in the uprights 2 and 3, respectively. The crossbar 33 is provided with flanges 40 and 41 in which are formed orifices 42 and 43, respectively, for locking in position. The locking of the cross member 33 is made with tapered pins 44 and 45 engaging in the orifices 42 and 43 of the flanges 40 and 41 and fixed on the control wheels 46 and 47, respectively. In addition, provision has been made

  crosses 33 a groove 48 (Figure 2) in which-

  pledge the wall 34 by its upper part. A thicket

  49 is provided on the lower part of the wall

  34 for mounting the support 35 of the forming roll 5.

  The support 35 of the forming roll 5 consists of rollers 50 (FIG. 3) mounted on axes 51 fixed in

  the thickening 49 of the wall 34 in two parallel rows

  following the generatrix of the roll forming 5. Pen-

  At work, the rollers 50 are in contact with the roll forming 5. To keep the roll forming 5 in constant contact with the rollers 50 under the action of the forces generated during the folding of the blank 14, the angle ". Between the tangents to the generatrices of the roll forming 5 is equal to at most 140, which is ensured by the distance between the rollers 50 and the diameter d of the roll forming 5, which is chosen as a function of the diameter of the blank to be folded. The minimum angle is limited by

  the permissible load acting on the roller 50.

  To bend blanks from a metal sheet of 0.5 to 3.0 mm thick and metal sheets and alloys of high mechanical strength, it is possible to

  climbs the rollers 50 along the entire generator of the wheel

  water forming 5, as shown in Figure 1.

  For the folding of short blanks from thin sheets less than 0.5 mm thick, and metal sheets and soft alloys in a single pass, the folder according to the invention comprises a mechanism 52 (Figure 4) for spacing a portion of the rollers 50 from the surface 6 of the roll forming 5, comprising a jack

  53, the rod 54 of which is connected via

  a carrier 55 and a support 56 and a bearing element 57 to the spreading rollers 50. The support 56 is fixedly fixed to the bearing element 57 having a profile identical to the profile of the wall 34 and disposed in an opening 58 formed in the medial portion of the wall 34. In the opening 58 is provided an eye 59 which engages in the groove 60 of the support element 57. With the aid of the axis 61, the support element 57 is connected to the wall 34. The body 62 of the hydraulic cylinder 53 is fixed to

  using another support 63 on the crossbar 33.

  In the folder according to the invention, at the ends of the wall 34 (FIG.

  devices 36 and 37 for maintaining the roll of

  The device 36 shown in FIG. 5 comprises a support 64 fixed on the end face of the wall 34, an axis 65 mounted by one of its ends.

  in a blind hole 66 of a support 64 with possible

  it is able to move in the axial direction, and at its other end in a bore 67 of the roll forming 5. In the working position, the shaft 65 is held in the bore 67 of the roll forming a spring 68 disposed in the orifice 66 of the support 64 and supported by one of its end faces against the bottom of this orifice 66, and by its other end face, against the axis 65. To remove the axis 65 in the In order to deposit the roll forming 5, there is provided a lever 69 connected to the axis disposed in the support 64 through an orifice

  debouching 70 practiced in the latter.

  The device 37 is executed in a manner

  logue, but is not shown in Figure 5.

  To adjust the folding machine for another diameter d (FIG. 3) of the roll forming 5, the folder according to the invention is provided with a mechanism 71 (FIG.

  the help of which, during adjustment, the

  of the roller 12 (FIG. 1) with elastic coating 13

  relative to the wall 34. This mechanism is linked cinema-

  It is shown in FIG. 6 that a portion of the mechanism 71 mounted on the hydraulic cylinder 19 effecting the radial displacement of the elastic-coated roller 13 is shown in FIG. between the adjustment displacement mechanism 71 and the radial displacement mechanism 18 comprises load screws 72 fixed by means of pins 73, at one end, via a fork 74, to the hydraulic cylinders 19 and 20 (FIG. 1) effecting the radial displacement of the elastic-coated roll 12. The other end of the screws 72 (FIG. 6) is free. Each screw 72 is provided with a nut 75 with a tangent ring 76 resting on the bearing 77, which bears, in turn, on the body 78 of the adjustment displacement mechanism 71 fixed to the frame 1. On each body 78 of the adjusting movement mechanism 71, the supports 79 and 80 of the worm shaft 81 are arranged. In order to ensure the displacement of the load screws 72 in synchronism during the adjustment, the screw shaft 81 endless is common to the two tangent crowns 76 and is rotated by a control 82 having a

  reducer 83 and an electric motor 84.

  In the folder according to the invention, the mechanism 71 for adjusting the displacement of the roller 12 (FIG. 1) with elastic coating 13 consists of a rule 85 (FIG. 6) fixed on the frame 1 and a flexible strip 86 kinematically bound. at the mechanism 18

  radial displacement of the roller 12 (FIG. 1) has been

elasticity 13.

  Rule 85 (FIG. 7) is connected to frame 1 (FIG. 6) via a panel 87 fixed on supports 88 and 89 which are mounted, in turn, in a box 90 connected via the upright 2 on the frame 1. On the ruler 85 is carried a scale 91 (FIG. 7), each division of which corresponds to a value of radial displacement of the roll 12 with a coating

elastic 13-

  One end of the flexible band 86 is fixed

  on one of the bodies 78 (Figure 6) of the movement mechanism

  setting member 71, the strip 86 itself being engaged between the rollers 92, 93, 94, 95 and 96 respectively mounted on the support 97 of the body 78 of the

  mechanism 71 of adjustment displacement, on the sup-

  ports 88 and 89 and the support 98 of the fork 74 of the load screw 72, fork secured to the body 99 of the hydraulic cylinder 18 for radial displacement of the roller 12 with elastic coating 13. A weight 100 is fixed on the second end of the band 86 for its voltage. An opening 101 is made in the upright 2 for the passage of the strip 86 through the upright 2 of the frame 1. The strip 86 is provided with a scale 102 (FIG. 7), each division of which corresponds to a diameter d of the roll.

forming 5.

  The diameter of the forming roll depends on the diameter, the wall thickness and the material of the parts made by folding on the two-roll brake. Depending on the range of diameters of the rollers 5 required for folding on the folder in question, it is equipped with a number of supports 35 ensuring a stable position of the forming rollers 5 on the rollers 50. Figure 2 shows a folder comprising three walls 34, 103 and 104 fixed to the crosspiece 33 and on which are mounted the supports 35, 105 and 106, respectively, carrying the forming rollers 5, -) 7 and 108. In this embodiment, the flexible strip comprises three scales 102, 109 and 110 (FIG. 7) whose division numbers correspond to the diameters of the forming rollers 5, 107 and 108 (FIG. 2)

  mounted on the supports 35, 105, 106.

  The housing 90 in which is the rule

  and the band 86 is protected by a trans-

parent 111.

  The setting of the two-roll brake is

done in the following way.

  By turning the control knobs 46 and 47 (FIG. 1), the tapered pins 44 are pulled out.

  and 45 of the orifices 42 and 43 of the flanges 40 and 41.

  Then, the crossbar 33 is rotated relative to the axis and the wall 34 corresponding to the roll forming 5 is mounted in the vertical position by orienting the rollers 50 downwards. The wall 34 is chosen for the corresponding roller so that the value of the angle "between the tangents and the generatrices of the rollers 50 at the points of contact thereof with the roll forming 5 is not greater than

at 140.

  Using the handle 69 (Figure 5),

  mote the axis 65 by compressing the spring 68 so that the end of the axis 65 is embedded in the orifice

66 of the support 64 of the device 36.

  The roll forming 5 (FIG. 2) with hard surface 6 and having a diameter d chosen as a function of the diameter, the thickness and the material of the blank 14 to be folded is mounted parallel to the axis of the rollers 50, and

  the handle 68 is released. Spring 68 returns the end

  mity of the axis 65 in the bore 67 of the forming roll 5.

  By operating in a similar manner, the axis 65 is engaged in the bore 67 of the roll forming 5 made on

the other end of the roll 5.

  When this is done, the electric motor 84 is started and its rotation is transmitted via the gear unit 83 to the worm shaft 81 and to the tangent ring 76 provided with the nut 75. By turning and pressing the bearing 77, the nut communicates the movement

  translation to the load screw 72.

  The roller 92 moves from bottom to top joint

  With the support 98 fixed on the fork 74 of the load screw 72 and together with the screw 72, taking with it the band 86 which then passes through the rollers 96, 95, 94 and 93 and lifts the weight 100. As the web 86 moves, the scale 102 of the diameters d of the roll forming 5, carried on the web 86, moves

  also with respect to Rule 85.

  the electric motor 84 until the division corresponding to the diameter d of the roll forming 5, established on the axes 65, reaches the division 91 of the rule 85, which corresponds to the necessary value of the depth of depression of the roll forming 5 in the coating

elastic 13.

  This completes the setting operation.

  The folder works as follows.

  The engine liquid being forced under pressure in the cavities of the hydraulic cylinders 19 and 20, the rods 25 and 26 of the cylinders 19 and 20, acting by the eyes 27 and 28 on the flanges 10 and 11, rotate

  the latter in relation to axis 9.

  At this moment, the roller 12 with elastic coating

  Fig. 13 approaches the forming roll 5, contacts the latter and applies it to the rollers 50 of the support 35. When the elastically coated roll 13 is moved later, the coating 13 deforms and the roll forming sinks into the

coating 13.

  After that, the rotation control of the elastic-coated roller 13 is started. The elastic-coated roller 12. In this case, the elastic-coated roller 13 drives the roller.

  forming 6 in rotation by friction.

  The preform 14 is advanced between the rollers 12 and in rotation, which cause said roughing by friction and move it. The forces generated during the deformation of the elastic coating 13 fold the blank 14 with respect to the roll forming 5. The same forces act simultaneously on the roll 5. The roll - 5, resting on the rollers 50 arranged along its entire generator, is in favorable conditions with respect to the action of the bending moment with respect to its longitudinal axis and undergoes no bending exceeding the admissible value. The roller 12 continues to rotate until one half of the perimeter of the blank 14 is curved, which is made possible by the fact that the wall 34 is thin. After the edge of the blank 14 has reached the wall 34, the blank continues to advance and

  fold it down until one half of the

  meter passes through the rollers 5 and 12. Then, the rotation control 17 of the roll 12 is put to rest.

  elastic coating 13, the liquid is sent under pressure.

  in the upper cavity of the cylinders 19 and 20. The

  rods 25 and 26, going down, rotate through

  The elastic-coated roller 12 moves away from the blank 14 and the roll forming 5. The roll forming 5 is suspended by its bores 67 at the pins 65 of the devices 36 and 37. intended to hold the forming roll 5 during removal

  folded blank 14. The blank 14 is removed from the blank

forming area.

  Then the sanding roll 13 is pressed again into the elastic coating 13, the roll 5 is rotated and the second half of the blank 11 is folded by operating in a manner

analogous to the previous case.

  Folding of blanks using the mechanism

  52 for moving a portion of the rollers 50 away from the

  The surface of the forming roll 5 is as follows.

  To fold short blanks from sheet metal

  thin metal whose length is equal to or less than

  greater than the support member 57 (FIG. 4), the folding is performed by using the mechanism 52 to move a portion of the rollers 50 away from the surface

6 of the forming cylinder 5.

  Radial displacement and rotation of the wheel

  water 12 are carried out in a similar manner to the case described above. The blank is moved between rolls 5 and 12 by 5 to 10 times the thickness of the blank. At this point a preliminary folding of the edges of the blank is carried out, then the rotation is stopped, then one. reverses the direction of rotation of the rotation control; during this rotation,

  the blank leaves rolls 5 and 12. The same operation

  This is done for the second edge of the blank.

  This done, we put the roller 12 in rotation

  and is transferred to the lower position

  the roll forming the action of the effort.

  After that, the liquid under pressure is sent into the lower cavity of the hydraulic cylinder 53; acting through the support 56, the rod 55, is rotated the element 57 with a portion of the rollers 50 relative to the axis of the eye 59 and

  thus releases the opening 58 of the wall 34.

  By operating in a manner analogous to the case described above, the radial displacement and the

  rotation of the roll 12 with elastic coating 13.

  Then the blank, whose edge is folded, is engaged between the rollers 5 and 12 and folded into a

  only passes until a circular outline.

  This is done, the roller 12 is moved downwards and the folded blank is withdrawn along the generatrix of the roll forming 5. The liquid under pressure is sent into the

  cavity of the hydraulic cylinder 53 and the element

  support 57 in the starting position. The two-roll sheet bending machine can be successfully used under the conditions of manufacturing a wide range of tubular parts in small series from aluminum and titanium alloy sheets for de-icing systems and life of aircraft personnel, as well as stainless steel sheets. This

  Folder can bend parts from sheet metal in alli-

  titanium up to 1.5 mm, aluminum sheets up to 3 mm thick, parts length

  tubular products up to 1600 mm. In comparison

  press brakes, the roller

  provides a 5x increase in fold efficiency and reduces the volume of operations by more

adjustment made by hand.

Claims (7)

R E V E N D I C A T I 0 N S CLAIMS   1.- Folder with two rolls for sheets, of the type comprising a frame provided with uprights (2, 3), an interchangeable roller (5) with a hard surface (6), mechanically linked to the uprights (2, 3), and a a roll (12) with an elastic coating (13), mounted on the uprights (2,3) and folding the flat blank (14) with respect to the forming roll (5), said roll (12) being equipped with a rotation (17) and a radical displacement mechanism (18), characterized in that it is provided with a crossbar (33) mounted in the uprights (2,3) of the frame (1) and carrying at least one   wall (34) on which is mounted a support (35) supporting   both the forming roll (5) during the folding process, and devices (36, 37) for holding the forming roll (5) during removal of the blank   folded (14) and mounted at the ends of said cross.   2. Folder according to claim 1, characterized   said support is executed in the form of rollers (50) mounted parallel in two rows along the generatrix of the forming roller (5) and so   the maximum value of the angle (0) between   the generatrices of the rollers (50) at the points of contact thereof with the forming roll (5) is   at most.   3. Folder according to one of claims 1 and 2,   characterized in that the rollers (50) are mounted   the entire generatrix of the forming roll (5).   4. Folder according to one of claims 1, 2   and 3, characterized in that it comprises a mechanism (52) for moving a part of the rollers (50) away from the   surface (6) of the forming roll (5), this mechanism comprises   both a hydraulic cylinder (53) connected by a rod (55) with rollers (50).   5. Folder according to one of the preceding claims   characterized in that each device (36) for holding the forming roll (5) has an axis (65) mounted at one of its ends in the wall (34) so as to be able to move axially, and engaging at its other end in a front bore (67) of the forming roll (5).   6. Folder according to one of the preceding claims   characterized in that it comprises a mechanism (71) for moving the roll (12) elastically coated (13) for the adjustment in position of the roller relative to the wall (34) when adjusting the brake for another diameter of the forming roll (5), said mechanism (71) being kinematically connected to the mechanism (18) of radial displacement of the roll (12) with elastic coating (13).  7. Folder according to claim 6, characterized in that said mechanism (71) for moving the roller (12) elastically coated (13) is executed as a rule (85) fixed on the frame (1) and a flexible band (86) kinematically connected to the radial displacement mechanism (18) of the elastic-coated roller (12), the divisions of the scale (91) marked on the ruler (85) each corresponding to a determined value of the radial displacement of the roll (12) with elastic coating (13), and the divisions of the scale (102) marked on the strip (86) each corresponding to a determined diameter forming roll (5).