FR3005589A1 - MACHINE FOR FOLDING A FLAN - Google Patents

Abstract

The invention relates to a machine for clamping a blank (15) comprising a bed (10) provided with a plate (11), a blank holder (22), movable between an open position and a position of closure, and a folding mechanism (55). Said machine comprises return means (27) configured to recall the blank holder (22) in the direction of approaching the plate (11).

Description

The present invention generally relates to machines for folding blanks, usually called folders, which allow the folding of metal blanks, for example the folders which are intended for zinc-plating on construction sites.

A folder generally comprises a foldable deck for acting on the blank to be folded, and a fixed bed base that forms a worktable. For retention on this fixed base of the blank to work, the folder also comprises a blank holder which is rotatably mounted on the fixed bed between an open position, according to which it is possible to introduce or remove the blank between the apron and the blank holder, and a locked closed position, for which the blank to work is clamped between said bed base and the support nose formed by one of the longitudinal edges of the blank holder.

However, with such a bender known from the state of the art, there is observed a tightening drift due to the wear of certain parts or to their break-in. Thus, the clamping pressure can not be ensured throughout the life of the machine. It is then necessary to provide a specific adjustment system of nut / locknut type or adjustment cam type, and regularly intervene on the folder to adjust it. This intervention is technical and requires a good knowledge of the machine. In addition, when the operator wishes to work blanks of different thicknesses, he must also intervene on the specific adjustment system of the machine to ensure that the blank is tight between the bed base and the support spout of the greenhouse -flan, which is tedious as explained above. The present invention aims to provide a new folding machine for which the operator does not need to intervene on the adjustment of the parts 30 of the machine to ensure that the blank is tight between the bed base and the support pin of the blank holder in the closed position.

Another object of the present invention is also to provide a new machine for folding blanks of different thicknesses without the operator having to intervene on the adjustment of the parts of the machine.

For this purpose, the subject of the invention is a machine for folding a blank comprising: a support structure, called a bed base, comprising a plate, a member, called a blank holder, movable relative to the bed base plate between an open position in which said blank can be introduced between the bed plate and the blank holder, and a closed position in which the blank holder exerts, by one of its parts called the support beak, a force resting on the platen to hold the blank tightly between the platen and the spout, and - a folding mechanism arranged to fold said blank in the tightly maintained state of said blank between the platen and the spout , characterized in that said machine comprises return means configured for, at least in the closed position of the blank holder, to return said blank holder in the direction of approaching said plate. The presence of such return means ensures, in the closed position of the blank holder, an effective maintenance of the blank to work even when parts of the machine begin to wear. Said biasing means make it possible to catch any play between the support spout 25 of the blank holder and the blank supported by the bed base plate due to a drift of the adjustment of the folder which can appear over time. Similarly, these return means make it possible to ensure a good tightening of the blank between the blank holder and the bed base plate for different thicknesses of blank. The blank to be worked is then firmly pinched between the bed base plate and the blank holder support. This gives a mechanical system for automatic adjustment of the clamping sets without the use of specific adjustment tools. With such a machine, the machine wear drifts are compensated by the biasing means, and an optimum clamping pressure can be maintained, which reduces the need for adjustment and maintenance of the machine. Said biasing means may be of elastic type, such as a helical spring or spring blade, or of another type, such as a weight arranged to return the blank holder to the plate. According to an advantageous characteristic, said machine comprises a toggle mechanism configured to enable the blank holder to be moved relative to the bed base from said open position to said closed position in which said blank holder is kept locked by said knee mechanism. According to an advantageous characteristic, said toggle mechanism 20 comprises: a first connecting rod articulated to the blank holder, and a second link articulated to the bed base and the first connecting rod, the axis of articulation of the second connecting rod to the first connecting rod. being slidably mounted along at least a portion of the first link, preferably along an elongated opening, called a guide opening, provided in the first link, and said return means are configured to recall the axis articulation of the second connecting rod to the first connecting rod in the direction of an approximation of the axis of articulation of the first rod to the blank holder. The thickness variations of the blank can thus be absorbed by the displacement of the axis of the second connecting rod subjected to the return means.

According to an advantageous characteristic, said biasing means comprise a spring, preferably helical, which extends inside said guide opening formed in the first connecting rod.

According to a particular embodiment, one end of the spring is located on the side of the end of the guide opening farthest from the axis of articulation of the first connecting rod to the blank holder, and the opposite end of the spring is supported on the axis of articulation of the second connecting rod to the first connecting rod, to recall it towards the other end of the guide opening. Advantageously, said spring is a helical spring mounted around a rod which extends along a portion of the guide opening.

According to an advantageous characteristic of the invention, said toggle mechanism is arranged such that, in the open position, the plane passing through the axis of articulation of the first connecting rod to the blank holder and the axis of articulation of the second connecting rod to the first connecting rod, is located between the support pin of the blank holder and the axis of articulation of the second connecting rod to the bed base, and, in the locked closed position, the hinge axis from the second connecting rod to the bed base is located between the support nose and said plane. According to an advantageous characteristic of the invention, said toggle mechanism is arranged such that, to pass from the open position to the locked closed position and vice versa, the first and second links must cross a line of maximum resistance. corresponding to an aligned configuration between them of the hinge axis of the first connecting rod to the blank holder, the hinge axis of the second connecting rod to the first connecting rod, and the hinge axis of the second connecting rod to the bed base. Preferably, the blank holder comprises a plate comprising a first portion having a flat free edge forming said support nose, and a second portion forming a sloping face relative to said first portion. According to a preferred embodiment of the invention, said machine comprises an additional toggle mechanism, similar or identical to said toggle mechanism, said toggle mechanisms being spaced apart from each other to delimit between them, in the position of opening the toggle mechanisms, a passage introducing a blank between the bed base plate and the blank holder.

According to an advantageous characteristic of the invention, the blank holder being articulated to the bed base around an axis of articulation, the axis of articulation of the first connecting rod to the blank holder and the axis of articulation of the greenhouse. -flan the bed frame are located on either side of a plane passing through the axis of articulation of the second connecting rod to the bed base and orthogonal to the bed base. Preferably, said first rod is bent. In particular, in the locked closed position, the first connecting rod comprises a first section which extends substantially to the right of the support pin of the blank holder, and a second section which extends obliquely with respect to the first section in the direction of opposed to said support nose. The invention will be better understood on reading the following description of exemplary embodiments, with reference to the appended drawings in which: FIG. 1 is a perspective view from above of the machine according to the invention in the open position toggle mechanisms; - Figure 2 is a side view of the machine of Figure 1 in the open position; FIG. 3 is a side view of the machine of FIG. 1 in the locked locked position of the toggle mechanisms; - Figure 4 is a view of the machine of Figure 3 in the masked state of certain parts, including a portion of the first connecting rod to show the bed plate and the support plate of the blank holder. - Figure 5 is a view of the machine of Figure 3 in the masked state of certain parts, including the second connecting rod.

In the example illustrated in the figures, the blank folding machine 15, usually called a folder, comprises a fixed bed 10 and a blank holder 22 articulated about an axis A4 via an arm 4 relative to the fixed bed 10. flan is for example a sheet of metal.

In the embodiments shown, the bed base 10 comprises a hollow profile 100, of quadrangular cross section, and in practice square, with two flanges 12 reported transversely to the ends of this section 100.

Said bed base 10 also comprises a plate 11, also called working table, projecting on the upper face of the profile 100. The plate 11 is formed of a single flat, and runs from one of the two flanges 12 to the other and extends cantilevered along one of the longitudinal edges of the profile 100, in this case its forward longitudinal edge. Thus, this plate 11 is intended to form the useful part of the bed base 10, that is to say that which must be placed on the blank 15 to work. The blank holder 22 is rotatably mounted on the bed base 10 about the axis A4 between an open position (see FIGS. 1 and 2), for which said blank holder 22 allows access to this bed base 10, and a position of closure, Figures 3 to 5, for which a portion of said blank holder, called the support nose 23, applies a force on the plate 11 of the bed to hold the blank to work 15. For the passage of the blank holder 22 of the open position to the closed position and vice versa, the machine comprises two toggle mechanisms 5. With reference to a direction of insertion of the blank between the blank holder 22 and the plate 11 of the bed base, said toggle mechanisms 5 are spaced apart. one of the other in a direction transverse to the insertion direction of the blank. The support plate 23 of the blank holder and the plate 11 of the bed base 10 each have, in the example illustrated in the figures, an elongate shape with a longitudinal axis orthogonal to the insertion axis of the blank. Each of the axes of articulation of a mechanism 5 is coaxial with an axis of articulation of the opposite mechanism 5. One of the mechanisms 5 is thus coupled to one end of the blank holder 22 and to the corresponding end of the bed plate 11, while the other mechanism 5 is coupled to the opposite end of the blank holder 22. and at the corresponding end of the bed base plate 11. In the remainder of the description, when describing a part of one of the toggle mechanisms 5, this description also applies to the corresponding part of the mechanism. toggle opposite. Each toggle mechanism 5 comprises a first connecting rod 25 articulated to the blank holder 22 by a hinge pin A1, and a second connecting rod 26 articulated to the bed base 10 by a hinge pin A2 and articulated to the first connecting rod 25 by a axis of articulation A3. The hinge axis A3 of the second link 26 to the first link 25 is slidably mounted along an elongated opening 250, called the guide opening, provided through the first link 25. Said guide opening is rectilinear. The parts of each toggle mechanism 5 are configured to move the blank holder 22 relative to the bed base 10 between an open position in which said blank 15 can be inserted between the bed 11 of the bed base 10 and the clamp. 22, and a locked locking position in which the blank holder 22 exerts by its support nose 23, a bearing force on the plate 11 to maintain the blank 15 clamped between the plate 11 and the support nose 23. Each connecting rod 25 extends transversely to the blank holder 22 and is articulated to the bed base 10 by the connecting rod 26. In the embodiments shown, the blank holder 22 comprises an angle-type body which has a front panel which The other end of this flange, the rear flange 220, extends obliquely with respect to said support flange 23. In a manner similar to sommier, the blank holder 22 is provided with two flange 24 opposing located at the ends of said angle body and to which are coupled the hinge pins A1 and A4. As a reminder, Al is the axis of articulation between a connecting rod 25 and the blank holder 22, and A2 the axis of articulation between a connecting rod 26 and the bed base 10. In the embodiment shown, the connecting rod 26 carries a shaft end which extends in the opening 250 for guiding the rod 25 to form said hinge axis A3 between the rod 25 and the rod 26 corresponding. The shaft end can slide inside said opening when the rod 26 is moved. At least one of the connecting rods 26 is securable to an operating lever 29. As explained above, the blank holder 22 comprises on the side opposite its support nose 23, an arm 4 by which it is articulated to the flange 12 of the bed base 10. As a reminder, A4 is the axis of articulation thus intervening between the arm 4 of the blank holder 22 and the box spring 10. For a lock type toggle, the plane that contains the axis of articulation Al of the blank holder 22 to the rods 25 and the axis of articulation A3 of the rods 25 to the rods 26 is, for the closing position of this blank holder 22, beyond the axis of articulation A2 connecting rods 26 to the bed base 10 relative to the support nose 23 of said blank holder 22. To do this, each rod 25 is bent in the embodiments 5 shown for bypassing the axis A2. It should be noted that the guide opening 250 is formed in the portion of the first connecting rod 25 opposite the support nose 23 with respect to the bend formed by said connecting rod 25. Each toggle mechanism 5 also comprises a helical spring 27 configured to, in the closed position, recall the hinge axis A3 of the second connecting rod 26 to the first connecting rod 25 in the direction of an approach of the hinge axis Al of the first rod 25 to the blank holder 22. The coil spring 27 extends inside the guide opening 250. In particular, one end of the spring 27 is located on the side of the end of the guide opening 250 farthest from the hinge axis Al of the first connecting rod 25 to the blank holder 22, and the end opposite of the spring bears on the axis A3 of articulation of the second connecting rod 26 to the first connecting rod 25, to recall it towards the other end of the opening 250 for guiding. Said spring is mounted around a rod 28 which extends along a portion of the guide opening 250. The folder also comprises, on the front side of the bed base 10, a folding mechanism comprising an apron 55, which, according to the methods which, to those skilled in the art, will not be described in detail here, is mounted rotating on this bed base 10, by means of holes formed in the flanges 12. In general, said deck 55 is movable, preferably by pivoting, from an inactive position, corresponding for example to a lowered position, to a position active, corresponding for example to a raised position, wherein said apron is brought against the blank held tight to fold said blank around the clamping line defined by the clamping nose 23.

It can be provided that this deck 55 comprises, on the one hand, a profile, which extends over the entire length of the profile of the bed base 10, between the flanges 12 thereof, on the side of the front face of this profile, and which is coupled to any lever adapted to allow the maneuver, and, secondly, in the manner of the plate 11 of the bed base 10, a plate, which is reported, for example by welding, on said profile, in s extending cantilever over it, and whose upper edge, for the rest position of the assembly, is level with the upper surface of this plate of the bed base. For the realization of such an apron, those skilled in the art can refer to the patent application published under the number FR2624037. The folder may also include, associated with its bed base 10, a rail adapted to guide a cutting device, not shown, along the support nose 23 of the holder 22. For producing such a device cutting, the person skilled in the art can also refer to the patent application published under the number FR2624037. For the folding of a blank 15, it is first tilted to the open position of the blank holder 22, as shown in FIGS. 1 and 2. It should be noted that in the example illustrated in FIGS. at 5, the blank 15 is shown in the folded state. To do this, the connecting rod 26 of one of the mechanisms 5 is tilted upwards by means of the lever 29. This tilting causes the rod 25 to be lifted, and thus, by the arm 4, pivoting of the blank holder 22 around its axis of articulation A4. The blank 15 to be worked is then placed on the plate 11 of the bed base 10, 30 It is then proceeded to tilt down the rod 26, which lowers the rod 25, and thus leads the blank holder 22 to rotate, around its articulation axis A4, towards its closed position.

During this movement, and the spacings having been established accordingly, there is the crossing of a line of maximum resistance when the plane containing the hinge axis A1 of the blank holder 22 to the rods 25 and the axis articulation A3 connecting rods 25 to connecting rods 26 reaches the axis of articulation A2 of the connecting rods 26 to the bed base 10, with, for the assembly, a knee-type locking system beyond the latter. Once past this line of maximum resistance, that is to say once the plane passing through the axes A1 and A3 crosses the axis A2 on the opposite side to the spout 23, the blank holder 22 is locked in position closing against the blank 15 resting on the plate 11 of the bed base 10. The return spring 27 makes it possible to exert a force on the axis A3 in the direction of a reduction in the distance between the axes A1 and A3 and thus to generate an additional support force of the blank holder 22 towards the bed base 10 which catches any play between the parts of the machine which could affect the contact between the support plate 23 of the blank holder 22 and the blank 15 carried by the plate 11 of the bed base 10.

The blank 15 to be worked is then firmly gripped between the plate 11 of the bed base 10 and the support spout 23 of the blank holder 22. For the folding of the sheet, it is sufficient to tilt up the apron 55, for 25, pushed by it, the free portion of the blank 15 to work is folded against the support plate 23 of the blank holder 22, and that, as desired, it is thus folded. To reopen the machine, the operator will have to raise the connecting rod 26 by crossing the resistance line in the other direction. The present invention is not limited to the embodiments described and shown, but the skilled person will be able to make any variant within his mind.

Claims (10)

REVENDICATIONS1. Machine for folding a blank (15) comprising: - a support structure, called a bed base (10), comprising a plate (11), 5 - a member, called a blank (22), movable relative to the plate (11) of the bed (10) between an open position in which said blank (15) can be introduced between the plate (11) of the bed (10) and the blank (22), and a closed position in which the blank holder (22) exerts, by one of its parts called the support nose (23), a bearing force on the plate (11) to keep the blank (15) clamped between the plate (11) and the support nose (23), and - a folding mechanism (55) arranged to fold said blank in the tightly maintained state of said blank between the plate (11) and the support nose (23), characterized in that said machine comprises return means (27) configured for, at least in the closed position of the blank holder, to return said blank holder (22) in the direction of approaching said plate (11). 2. Machine according to claim 1, characterized in that said machine comprises a toggle mechanism (5) configured to allow to move the blank holder (22) relative to the bed base (10) from said opening position up to at said closed position in which said blank holder is held locked by said toggle mechanism. 3. Machine according to claim 2, characterized in that said toggle mechanism (5) comprises: - a first connecting rod (25) articulated (A1) to the blank holder (22), and - a second connecting rod (26) hinged (A2, A3) to the bed (10) and to the first connecting rod (25), the hinge pin (A3) of the second connecting rod (26) to the first connecting rod (25) being slidably mounted along with at least a portion of the first link (25), preferably along an elongated opening (250), called a guide opening, in the first link (25), and in that said return means (27) are configured to return the hinge axis (A3) of the second connecting rod (26) to the first connecting rod (25) in the sense of bringing the hinge pin (A1) closer to the first connecting rod (25) at the blank holder (22). 4. Machine according to claim 3, characterized in that said biasing means (27) comprise a spring, preferably helical, which extends inside said opening (250) for guiding formed in the first connecting rod ( 25). 5. Machine according to one of claims 3 or 4, characterized in that said toggle mechanism (5) is arranged such that, in the open position, the plane passing through the hinge axis (A1 ) from the first connecting rod (25) to the blank holder (22) and the hinge pin (A3) of the second connecting rod (26) to the first connecting rod (25) is situated between the support nose (23) ) of the blank holder (22) and the hinge pin (A2) of the second connecting rod (26) to the bed base (10), and that, in the locked closed position, the hinge axis ( A2) of the second connecting rod (26) to the bed (10) is located between the support nose (23) and said plane. 6. Machine according to one of claims 3 to 5, characterized in that said toggle mechanism (5) is arranged such that, to pass from the open position, to the locked locked position and vice versa, the first and second links (25, 26) must cross a line of maximum resistance corresponding to an aligned configuration of the hinge pin (A1) of the first connecting rod (25) to the blank holder (22); the hinge axis (A3) of the second link (26) to the first link (25), and the hinge axis (A2) of the second link (26) to the bed (10). 7. Machine according to one of the preceding claims, characterized in that the blank holder (22) comprises a plate comprising a first portion 30 having a flat free edge forming said support nose (23), and a second part ( 220) forming an inclined face relative to said first portion, said second portion (220) being connected by a hinge pin (A4) to the bed (10). 8. Machine according to one of the preceding claims taken in combination of claim 2, characterized in that said machine comprises a mechanism (5) additional toggle, similar or identical to said mechanism (5) toggle, said toggle mechanisms ( 5) being spaced from each other to delimit between them, in the open position of the mechanisms (5) toggle, a passage for introducing a blank (15) between the plate (11) of the bed base ( 10) and the blank holder (22). 9. Machine according to one of the preceding claims taken in combination of claim 3, characterized in that, the blank holder (22) being articulated to the bed base (10) about a hinge axis (A4), the hinge axis (A1) of the first connecting rod (25) to the blank holder (22) and the hinge pin (A4) of the blank holder (22) to the bed base (10) are located on the other than a plane passing through the axis of articulation (A2) of the second connecting rod (26) to the bed (10) and orthogonal to the plate (11) of the bed (10). 10. Machine according to one of the preceding claims taken in combination 20 of claim 3, characterized in that said first rod (25) is bent.