Device for adjusting the diameter of a guide channel for a rod

Abstract

The rod feeder (1) comprises a guide channel (10) centered on a constant guide axis (A-A), characterized in that the guide channel (10) is adjustable and is formed by an adjustable guide element, which, under the action of a device (2) for adjusting the diameter of the guide channel, defines a guide channel with a constant center (C) so that the guide channel is aligned with the maximum rod diameter (D) contained in the first position (P1). Max ) and the minimum rod diameter (D) at the second position (P2) Min ) corresponds to the rod diameter between them.

Description

Technical Field

[0001] The invention relates to a device and a method for adjusting the dimensions of a guide element in, for example, a bar feeder for feeding the bars into a processing machine, typically a lathe. Background Art

[0002] In the metallurgical industry, a bar feeder, also called a bar loader, is a common device used to feed long bars into a processing machine such as an automatic lathe, so that a series of continuous parts can be produced at the front end of the bar.

[0003] The plurality of bars are fed into the automatic lathe by means of a bar feeder having a guide channel adapted to the diameter of the bars and usually equipped with a fixing frame at its front end, usually referred to as a front support. The front support is the last guide element that comes into contact with the bars before they enter the lathe spindle and comprises a through hole through which the bars pass in order to limit the vibrations of the bars. The front support is designed to support the bars so as to allow a higher rotation speed in revolutions per minute (RPM) than the lathe spindle and also to limit the bars as firmly as possible, thus minimizing vibrations. For this purpose, the feed tube or the guide element can be made of a shock-absorbing material, such as polyurethane plastic or rubber, in order to dampen the vibrations of the bars as much as possible.

[0004] The guide channel upstream of the front support is usually formed by a long channel in the form of a half-tube having a rigid shell adapted to the specific rod diameter and which can be closed by an upper cover arranged above the tube.

[0005] Therefore, when rods of different sizes and diameters have to be transported, such guide elements are not suitable and the elements forming the guide channels have to be replaced, which is both cumbersome in operation and requires storage space to be allocated to accommodate a large number of rod diameters.

[0006] Alternatively, solutions with V-shaped jaws, often called "Toblerones", are used to grip the bar horizontally or laterally, to adjust more precisely to different diameters. However, such solutions have the disadvantage that, since the contact and holding surface with the bar is too small, they do not ensure sufficiently effective guiding properties to limit vibrations when the bar is rotated.

[0007] In order to solve these problems with regard to modularity and scalability of the diameter of the rod, other solutions have been proposed using adjustable guide channels. This adjustable channel is formed by two pivoting claws with semi-cylindrical guide parts that come into contact with or move away from each other and whose movement is combined with a height adjustment mechanism to maintain the axis of rotation of the rod, which must be kept at a constant height level. The solution disclosed in patent document EP3456444 proposes to place two identical semi-cylindrical guide parts symmetrically superimposed on each other, defining several open and closed positions for these guide parts in order to be able to adapt to different rod diameters. However, in both cases, the geometry achieved for the guide channel consists of a biconvex spherical lens, which always has the disadvantage of not being able to maximize the guide surface of the rod.

[0008] Therefore, there is a need in the prior art for a guide element which can be used, for example, in a bar feeder and which does not have these known limitations. Summary of the invention

[0009] The present invention aims to solve at least some of the above-mentioned and other disadvantages of the guide elements of the prior art for the guide channel of the bar feeder and / or the front bracket, for example to make such guide elements suitable for easily accommodating bars of different diameters, shapes or sizes, in particular by simple adjustment operations, while maintaining optimal guiding performance.

[0010] Another object of the invention is to further improve the imparted guiding properties and to provide a particularly efficient actuation mechanism for performing adjustment operations.

[0011] These and other objects of the invention are achieved in particular by a bar feeder comprising an adjustable guide channel according to claim 1. The dependent claims define more specific embodiments of the invention.

[0012] In particular, the first form of the present invention is realized by a rod feeder, which includes a guide channel centered on a constant guide axis, characterized in that the guide channel is adjustable and formed by an adjustable guide element, which is capable of defining a guide channel with a constant center under the action of a device for adjusting the diameter of the guide channel, so that the guide channel corresponds to a rod diameter between the maximum rod diameter in the first position and the minimum rod diameter in the second position.

[0013] Since a single adjustable guide element is used to form the guide channel, the size of the guide channel can be adjusted to a specific range of rod diameters without having to change the guide components, but by performing simple adjustment operations on one and a single identical component.

[0014] According to a preferred embodiment, the adjustable guide element is composed of a flexible shell covering a plurality of rods.

[0015] Since the guide housing is made of a flexible material, such as a plastic or rubber of the polyurethane series, not only can the size of the guide channel be easily adjusted by always using the same guide parts, but also simple adjustment operations can be performed, in contrast to the complex solutions known in the art. Moreover, the performance of the guide can be improved at the same time by maintaining the appropriate geometry of the coated rod as close as possible to the contour of the rod, for example similar to the diaphragm of a photographic lens, with a limited number of protruding edges. Vibrations can thus also be reduced for all possible rod diameters.

[0016] According to a preferred embodiment of the invention, the means for adjusting the diameter of the guide channel comprises a clamping device acting on the outer surface of the flexible guide housing. Due to this configuration, the actuating mechanism only needs to act on one component, which simplifies its implementation. In addition, since the clamping mechanism simply controls the amplitude of the upper opening of the guide housing to roll upwards by itself until it is reduced to zero, the roundness of the guide channel portion can be maintained regardless of its diameter.

[0017] According to a preferred embodiment of the invention, the clamping device comprises pivoting rollers placed on the outer surface of the flexible housing, the position of these rollers defining the size of the guide channel and the corresponding rod diameter. Since the rollers rotate around an eccentric axis and their number is at least two, the height of the opening can be managed simply by acting as a collet.

[0018] According to a preferred embodiment of the invention, the clamping device also comprises an actuating piston which acts on a cam for driving the rollers. The actuating device is thus always designed in a very simple manner, the cam being driven in a pivoting motion when the piston is extended. In addition, by having a single cam to actuate all rollers for clamping the flexible guide housing, thereby adjusting the diameter of the guide channel, this greatly simplifies the adjustment operation and improves reliability, since no dedicated cams are required for synchronization between the different actuating mechanisms of the different rollers.

[0019] According to a preferred embodiment of the present invention, the driving cam is also provided with a plurality of actuating grooves, which cooperate with corresponding driving pins arranged on each roller. Due to this arrangement, the pivoting of the cam caused by the piston movement is very simple and synchronously transmitted to all rollers at the same time without increasing the complexity of the entire actuating mechanism.

[0020] According to a preferred embodiment of the present invention, the number of rollers of the clamping device is an even number, and the roller drive cam is arranged to rotate half of the rollers in a first rotation direction and the other half of the rollers in an opposite second rotation direction. This configuration achieves the clamping function by bringing the upper edges of the guide housings closer to each other without simultaneously generating a rotational movement of the guide housings themselves.

[0021] According to a preferred embodiment of the invention, the device for adjusting the diameter of the guide channel also comprises an integrated height adjustment system. In this way, it is not necessary to provide a dedicated height adjustment system to keep the center of the guide channel at a constant level, which is a necessary prerequisite when feeding bars in a lathe, the center position of the guide channel being fixed relative to the bar feeder. The combination of the effectiveness of the diameter adjustment while maintaining the center of the guide channel gives the proposed system compactness.

[0022] According to a preferred embodiment of the invention, the clamping system comprises at least three rollers and is configured to together form a height adjustment system. According to such a configuration, no other elements other than the rollers are required to enable the flexible housing to act as a membrane to control the diameter of the guide channel. Their compression action on the outer surface of the flexible guide housing can adjust the diameter of the guide channel while maintaining its center.

[0023] According to a preferred embodiment of the present invention, the guide channel is also provided with a fixing pin inserted into the bottom of the flexible guide housing. Such a fixing element for the guide housing can prevent the guide housing from rotating together with the rod.

[0024] According to a preferred embodiment of the invention, an angular sector is comprised between 60 and 90 degrees, over which the upper opening of the flexible guide housing extends in a first position corresponding to the maximum rod diameter. Such an angular sector is such that the elastic deformation acting on the flexible guide housing does not exceed a predetermined stress level, thus preserving its service life by minimizing the risk of long-term creep and short-term fracture of the harder material. At the same time, this ensures that the rod is well enclosed in the flexible guide housing; the corresponding complementary portion of the housing is preferably between 270 and 300 degrees, thus always providing excellent guiding performance.

[0025] According to a preferred embodiment of the invention, the deviation between the maximum rod diameter in the first position and the minimum rod diameter in the second position corresponds to a range of about 20 mm, and a guide insert can be inserted into the flexible guide housing to define a new range of minimum and maximum diameters. This configuration allows the adjustment range of the guide channel diameter to be increased stepwise without having to impose greater constraints on the flexible guide housing, for which purpose the angular sector corresponding to the upper opening can instead remain substantially constant. Thus, the increased number of inserts makes it possible to simply vary the range of values ​​of the possible diameters while maintaining it substantially constant.

[0026] According to a preferred embodiment of the invention, the upper opening of the flexible guide housing also has a profile that allows mutual interlocking, such as a sawtooth or corrugated profile. This configuration of the flexible guide housing can further optimize the contact surface with the rod by allowing almost the entire circumference of the rod to be surrounded. The corrugated profile is even more preferred because it avoids any undue contact with the edge, thereby avoiding the formation of squeezes that may cause rod marks and generate vibrations. The guiding performance is thus further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In the following description, various embodiments of the present invention are described with reference to the following drawings.

[0028] Figure 1 is a perspective view of a guide channel equipped with the novel adjustment device according to the invention.

[0029] Figure 2A , Figure 2B and Figure 2C Front views of an adjustment device according to a preferred embodiment of the present invention in open, intermediate and closed positions, respectively.

[0030] Figure 3A A side view showing the adjustment device according to the preferred embodiment shown in the above drawings, Figure 3B and 3C They are cross-sectional views taken along a plane perpendicular to the guide axis of the transverse piston and the series of rollers, respectively.

[0031] Figure 4A , Figure 4B and Figure 4C The side view, front view and top view of a flexible guide housing used according to a preferred embodiment of the present invention are respectively shown, and the guide housing has a corrugated profile at its upper opening.

[0032] Figure 5A and Figure 5B The guide channels obtained by adding one or respectively two compensation inserts are shown.

[0033] When the same element numbers are used in different drawings, they are intended to indicate similar or corresponding features (e.g., element numbers with suffixes are intended to identify a specific component among a specific type of components). The guide channel diameter adjustment device claimed in the present application in different working positions corresponding to different rod diameters is shown with the same element numbers in different drawings, but will not be described in detail in the following drawings. DETAILED DESCRIPTION

[0034] Figure 1 A perspective view of a bar feeder 1 is shown, here more specifically the bar feeder part equipped with a guide channel 10 according to a preferred embodiment of the invention, according to which an adjustable guide element is formed in sections by a one-piece flexible guide housing 11, which is made of, for example, polyurethane plastic or rubber material to suppress vibrations, and which is made integral with a cylindrical frame 8 similar to a front bracket by means of fixing pins 5 inserted in its bottom. In other words, the bar feeder part shown in the figure itself can be considered to constitute a front bracket.

[0035] The cylindrical frame 8 of the guide channel 10 is itself arranged on a base plate 12, where the base plate is formed by several feet, and the device 2 for adjusting the diameter of the guide channel jointly comprises a clamping device 3 and a height adjustment device 4, wherein the clamping device 3 acts on the flexible guide shell 11 by a series of rollers 34 actuated by a piston 31 actuated by a drive cam 33; and the height adjustment device 4 is used to keep the center of the guide channel constant, that is, even when the diameter is reduced, so that the guide channel 10 is always centered on the guide axis AA.

[0036] More specifically, the configuration of the driving cam 33 having the actuating groove 332 can be divided into several stages, here three stages, and a driving pin 341 integrated with a roller 34 serving as an eccentric wheel is inserted into the actuating groove 332, that is, the eccentric wheel is a component that can be moved to rotate along an axis perpendicular to the anchor 6. Figure 1 In the embodiment, the ends of some of the rotation axes of the rollers are formed by nuts 7, which can be Figures 3A-3C Each cam 33 pivots under the effect of the extension of an actuating piston 31, the end of which is attached to a connecting piece 32 and, on the other hand, is connected to the upper end of the driving cam 33. The connecting piece 32 thus acts as a hinge between the actuating piston 31 and the driving cam 33.

[0037] Thus, the actuating piston 31 makes the rollers 34 rotatable at the level of each section where the drive cams 33 are arranged, via the connection 32 connected to the series of drive cams 33. The rollers 34, preferably four rollers 34 here, are arranged to compress the outer surface of the flexible guide housing 11 so that the shape of the guide channel 10 remains substantially cylindrical on the one hand and the center C of the guide channel 10 is maintained on the other hand regardless of the degree of opening and closing of the device 2 for adjusting the diameter of the guide channel caused by the stroke of the piston. In other words, the device 2 for adjusting the diameter of the guide channel is arranged to act like an optical film in general and is combined with the clamping device 3 for diameter adjustment and the height adjustment system 4 performed simultaneously by the rollers 34. This is possible because each drive cam 33 section has four rollers, of which the two upper rollers 34 have the main function of adjusting the diameter, while the two lower rollers 34 are used to lift the bottom of the flexible guide housing 11. However, according to a modified example not shown in the drawings, it is foreseeable that a series of two rollers 34 will be responsible for adjusting the diameter, thereby forming part of the clamping device 3, and then a separate height adjustment system 4 can be independently set to synchronously lift the bottom of the flexible guide shell 11 according to the degree of opening or closing of the guide channel 10.

[0038] In the following reference Figures 2A to 2C The mechanism for adjusting the diameter according to this preferred embodiment will be described in more detail below. Figure 2A The device 2 for adjusting the diameter of the guide channel is shown in a front view, which is integrated with the clamping device 3 and the height adjustment system 4. The position shown in the figure as the first position P1 corresponds to the open position, because there is an upper opening 11D at the height of the guide housing 11, which is here in its nominal rest position, which corresponds to the maximum possible diameter DMax of the guide channel 10, corresponding to Figure 1 In contrast, the guide axis AA can no longer be distinguished but becomes only the center C.

[0039] exist Figure 2A , 2B In all the figures of 2C, each of the four rollers 34, its corresponding driving pin 341, and the actuating slot 332 of the driving cam 33 used by the clamping mechanism 3 are marked respectively, namely:

[0040] - The first driving pin 341A disposed on the first roller 34A on the upper left is inserted into the first actuating groove 332A;

[0041] - The second driving pin 341B disposed on the second roller 34B at the lower left is inserted into the second actuating groove 332B;

[0042] - The third driving pin 341C disposed on the third roller 34C at the lower right side is inserted into the third actuating groove 332C;

[0043] - The fourth driving pin 341D arranged on the fourth roller 34D at the upper right is inserted into the fourth actuating groove 332D.

[0044] exist Figure 2A , the first drive pin 341A, the second drive pin 341B, the third drive pin 341C and the fourth drive pin 341D are located at the same level as one end of the first actuating slot 332A, the second actuating slot 332B, the third actuating slot 332C and the fourth actuating slot 332D, respectively. All other reference numerals are the same as Figure 1 The same.

[0045] At the maximum diameter D Max In the first position P1 of the flexible guide housing 11, the upper opening 11D extends over its largest angular sector, which can be reduced when the clamping device 3 is actuated. In this position, it can be seen that the flexible guide housing 11 rests on the cylindrical frame 8.

[0046] exist Figure 2B In the embodiment, the guide channel 10 is in an intermediate position corresponding to a rod diameter, referred to as the third position, which is smaller than the maximum diameter D of the first position P1. Max , but still better than Figure 2C The second position shown finds the minimum diameter D Min is large. At the middle position of the guide channel 10, the actuating piston 31 pivots the driving cam through the connecting piece 32, and all the pins (i.e., the first actuating pin 341A, the second actuating pin 341B, the third actuating pin 341C, and the fourth actuating pin 341D) have moved into the respective actuating slots (the first actuating slot 332A, the second actuating slot 332B, the third actuating slot 332C, and the fourth actuating slot 332D) in the clockwise direction S1. The action of the driving pins entering the actuating slots simultaneously causes the rollers, i.e., the first roller 34A, the second roller 34B, the third roller 34C, and the fourth roller 34D, to rotate relative to their respective rotation axes (Note: in Figure 2A Only the first rotation axis O1 of the first roller 34A and the second rotation axis O2 of the second roller can be seen, while Figure 2C In the figure, only the third rotation axis O3 of the third roller 34C and the fourth rotation axis O4 of the fourth roller 34D can be seen. However, all of these axes are shown in Figure 3B and 3C ). Figure 2A and Figure 2BBy comparison, it can be seen that the upper opening 11D of the flexible guide shell 11 has been reduced in size, and a portion of the rollers 34A, 34B, 34C and 34D protrude toward the interior of the cylindrical frame 8 until they are resting against the outer surface 11A of the flexible guide shell 11 to compress it inwardly and reduce the diameter provided by the guide channel 10.

[0047] Figure 2C Corresponding to the closed position, in which the flexible guide housing 11 of the guide channel 10 is completely closed without the upper opening 11D, the two upper edges of the housing contact each other to reduce the diameter to its minimum. Min In the second position P2, it can be seen that the first drive pin 341A, the second drive pin 341B, the third drive pin 341C, and the fourth drive pin 341D are now respectively positioned at the level of the other end of the first actuating slot 332A, the second actuating slot 332B, the third actuating slot 332C, and the fourth actuating slot 332D, which can be referred to Figure 2A Therefore, the rollers, namely the larger part of the first roller 34A, the second roller 34B, the third roller 34C, and the fourth roller 34D, protrude toward the inside of the cylindrical frame 8 to perform the adjustment function on the diameter of the guide channel 10 while maintaining its center C.

[0048] The following Figure 3A , 3B and 3C are intended to explain in more detail the configuration of the device 2 for adjusting the diameter of the guide channel according to the preferred embodiment described in the above-mentioned figures, and in particular to illustrate how the device can maintain the roundness of its shape and its center C while performing size adjustment of the guide channel by using a roller 34 to act as a compressible flexible guide shell 11 to clamp the eccentric wheel. Figure 3A Display according to the special Figure 1 A side view of a device 2 for adjusting the diameter of a guide channel according to a preferred embodiment is shown. The cylindrical frame has openings in three different sections (in Figure 3A Not shown, but in Figure 3C 3 ), in three different sections there are arranged different series of rollers 34 actuated by corresponding drive cams 33. In this context, these rollers are cylindrical and attached to an anchor 6 and are mounted rotatably around an axis eccentric with respect to the center of the rollers, the ends of the rollers being threaded and integral with the anchor 6 by means of nuts 7. In all the figures to be described below, the guide channel 10 is shown in the region corresponding to the maximum rod diameter D Max In the first position P1, the flexible guide housing 11 rests on the cylindrical frame 8. Figure 3AIn FIG. 1 , two cutting planes perpendicular to the guide axis, respectively crossing the piston (cutting plane BB) and the series of rollers (cutting plane CC), are shown. Figure 3B and 3C Views along these cutting planes are shown respectively.

[0049] At the cutting plane BB corresponding to the transverse actuating piston 31 Figure 3B In the figure, the individual positions of the axis of rotation of each roller in which the nut 7 is arranged can be seen:

[0050] - A first rotation axis O1 of the first roller 34A

[0051] - The second rotation axis O2 of the second roller 34B

[0052] - a third axis of rotation O3 of the third roller 34C, and

[0053] - a fourth axis of rotation O4 of the fourth roller 34D.

[0054] Despite Figure 3B 1 and 12 only show the first drive pin 341A of the first roller 34A, the second drive pin 341B of the second roller 34B, and the third drive pin 341C of the third roller 34C, but the fourth drive pin 341D of the fourth roller 34D is not shown. Figure 3B The above-mentioned drive pins shown can also be seen in the section corresponding to the cutting plane CC of the transverse roller 34. Figure 3C middle.

[0055] Figure 3B and Figure 3C 1 and 2 show the direction of rotational actuation of each roller 34 during the operation of adjusting the diameter of the guide channel 10, and it can be seen that the rollers located on the left side of the flexible guide housing 11, namely the first roller 34A and the second roller 34B, are actuated to rotate in the counterclockwise direction (the second rotational direction S2), while the third roller 34C and the fourth roller 34D are driven in the clockwise direction (the first rotational direction S1). In other words, according to the configuration proposed for the guide channel diameter adjustment device 2, all of the above-mentioned drive pins 341A, 341B, 341C, 341D are in the same rotational direction in the respective actuation slots 332A, 332B, 332C and 332D, i.e., in particular Figure 2BThe first rotation direction S1 shown is driven. This therefore means that the solution for performing the adjustment is not only simple, but also very intuitive, since the rollers exert an inwardly and symmetrically compressive force on the outer surface 11A of the flexible guide housing 11, causing this outer surface 11A to deform like an optical film around its center C. In addition, the adjustment is very gradual and very smooth, thanks to the use of the rollers 34 as clamping eccentrics, whose outer surfaces act as compression elements by resting against the outer surface 11A of the flexible guide housing 11.

[0056] exist Figure 3C In the cutting plane CC showing the series of rollers 34, four openings (first opening 81A, second opening 81B, third opening 81C, fourth opening 81D) in the cylindrical frame 8 are shown, which serve as passages for the first roller 34A, the second roller 34B, the third roller 34C and the fourth roller 34D, respectively. Each of the first outer surface 342A of the first roller 34A, the second outer surface 342B of the second roller 34B, the third outer surface 342C of the third roller 34C and the fourth outer surface 342D of the fourth roller 34D abuts against the outer surface 11A of the flexible guide housing to perform the functions of clamping and height adjustment, or what should be called the function of maintaining height. Therefore, as shown in most of the figures, the device 2 for adjusting the diameter of the guide channel acts as both the clamping system 3 and the height adjustment system 4 through the rollers 34 only under the action of the actuating piston 31.

[0057] Figure 4A , 4B 4C show the side view, front view and top view of the flexible guide housing 11 separated from the bar feeder, respectively, which is used according to a preferred embodiment of the present invention to further improve the guiding performance. Figure 4A As can be seen in the figure, the flexible guide housing 11 has an upper opening 11D in the rest position, and its upper opening does not show straight edges, but rather a corrugated profile 11E is arranged thereon, because of this arrangement, the rod guided by the inner surface 11B of the flexible guide housing 11 does not come into contact with the edge, but simply wraps around without contacting the protruding edge. Figure 4C Such a corrugated profile as shown allows vibrations and shocks to be reduced, thereby further improving the guidance properties compared to known guide channels.

[0058] In addition, Figure 4A and 4CAs can be seen in the figure, at least one lower insertion hole 11C, preferably several lower insertion holes 11C are arranged at the bottom of the flexible guide housing 11, so that snap-on parts such as the fixing pin 5 shown in the previous figure can be inserted into these insertion holes to ensure that the upper opening 11D always remains in the same orientation relative to the cylindrical frame 8 and cannot be moved sideways, or worse, downwards. However, the fixing pin 5 is intended to allow a degree of freedom of vertical translation, so that when the flexible guide housing 11 is clamped, the base of the flexible guide housing 11 can be slightly moved upwards, so that the reduction in the diameter of the guide channel 10 does not affect its center C, which is always aligned with the guide axis AA.

[0059] Depend on Figure 4B It can be seen that the angular sector α measured from the center C of the flexible guide housing 11 (corresponding to the center C of the guide channel 10 after installation) is preferably between 60° and 90°, even more preferably between 70° and 80°, so that the elastic deformation is not too significant when adjusting, while maximizing the complementary angular sector over which the guide envelope formed by the flexible guide housing 11 extends. In this way, the calibration adjustment can be preferably performed, allowing the rod to be guided within a range of diameters of about 20 mm, while providing optimal guiding characteristics.

[0060] In order to increase the adjustment range for other diameter values, a compensating insert may preferably be used as part of the present invention, such as Figure 5A and 5B shown.

[0061] Figure 5A and 5B Display for the same position (corresponding to the maximum rod diameter D Max The first position P1) and Figure 2A The same elements are shown as the device 2 for adjusting the diameter of the guide channel, so the common element numbers will not be repeated. Figure 2A and Figure 5A The only difference between the two is that a first additional guide insert 111 is added to the flexible guide housing 11. This addition can make the maximum rod diameter value greater than that based on Figure 2A The maximum rod diameter of the configuration in is about 20 mm lower. This value corresponds to Figure 2C As shown, the minimum rod diameter D obtained using the configuration with a completely closed guide channel in the second position P2 Min This allows adjustment by clamping, making it possible to obtain the minimum rod diameter D Min The new value is greater than the previous minimum rod diameter D Min 20mm smaller. Figure 5B In the embodiment, the second additional guide plug-in 111' is added to the first additional guide plug-in 111 so that it can be connected to the corresponding Figure 5A The rod diameter value is offset by 20 mm and adjusted to the new value range of the additional diameter. Therefore, according to this preferred embodiment, at least three 20 mm adjustment ranges can be arranged and added according to the number of plug-ins used, and a total adjustment range of 60 mm can be achieved, while maintaining the appropriate service life of the system and the best guiding performance, whereby, when adding plug-ins layer by layer, the angular sector α of the upper opening 11D corresponding to each additional guide plug-in will only increase slightly. In addition, the same fixing pin 5 can be used in each desired adjustment range, thus providing maximum expandability and flexibility.

[0062] Those skilled in the art will appreciate that the preferred embodiments described above are given by way of example only and should not be interpreted in a limiting manner with respect to the scope of protection of the present invention. Therefore, other actuating mechanisms may be used to adjust the diameter without departing from the scope of the present invention, such as using other forms of rollers (with elliptical portions instead of the circular shape of the cylinder shown in the drawings) to produce clamping eccentrics, other forms of actuating slots, different numbers of rollers and corresponding slots, etc. In addition, it should be understood that a flexible guide shell whose shape is completely closed when stationary, and an adjustment mechanism that can increase the diameter of the channel by expansion, rather than by clamping to reduce the diameter as described herein, or by another type of adjustable guide element to give the channel an adjustable diameter.

[0063] Similarly, without departing from the scope of the present invention, the diameter of the guide channel can be adjusted by using actuators other than rollers and cams, such as hydraulic cylinders, electric motors or pneumatic devices, which act directly on the flexible guide shell to provide different shapes, which are always concentric with the unchanged guide axis AA.

[0064] Thus, the device for adjusting the diameter of the guide channel claimed in the present case may include other types of mechanisms to achieve the adjustment function conferred by the clamping device 3 described. For example, a variable number of cylinders, preferably oriented in a star shape and all pointing to the center C of the guide channel, which remains constant regardless of the diameter of the bar to be guided, can be foreseen. In addition, according to the preferred embodiment described and illustrated in the previous figures, the adjustment of the diameter is carried out by clamping, which is adjusted with height to maintain the center C of the guide channel, thus around a constant guide axis AA like a diaphragm. In other words, the device 2 for adjusting the diameter of the guide channel is then combined simultaneously with the clamping device 3 and the height adjustment system 4 using the same components.

[0065] Likewise, a modified embodiment is foreseeable, according to which the diameter adjustment function is performed by pinching the top of the flexible housing, with the cylinder acting on the upper end on which the opening is arranged, while the height adjustment will be performed by a completely separate actuation mechanism, not acting at all on the diameter of the guide channel. For example, it can be a separate cylinder designed to adjust the height of a plate integral with the housing, or again actuate "Toblerones", whose movement towards and away from it will respectively lower or raise the bottom of the flexible guide housing. In this way, by synchronously managing the height adjustment related to the degree of opening or closing of the guide channel, it is possible to design a diameter adjustment mechanism that still has a clamping device for this purpose, but no longer has an integrated height adjustment device. Alternatively, the height adjustment device can be provided separately.

Claims

1. A bar feeder (1) comprising a guide channel (10) centered on a constant guide axis (AA), characterized in that The guide channel (10) is adjustable and is formed by an adjustable guide element which, under the action of a device (2) for adjusting the diameter of the guide channel, defines a guide channel with a constant center (C) so that the guide channel is aligned with the maximum rod diameter (D) contained in the first position (P1). Max ) and the minimum rod diameter (D) at the second position (P2) Min ) corresponds to the rod diameter between The adjustable guiding element is a flexible guiding shell (11) surrounding the rods.

2. A bar feeder (1) according to claim 1, wherein the device (2) for adjusting the diameter of the guide channel comprises a clamping device (3) acting on the outer surface (11A) of the flexible guide housing (11).

3. A rod feeder (1) according to claim 2, wherein the clamping device (3) comprises pivoting rollers (34) resting on the outer surface (11A) of the flexible guide shell (11), the positions of which define the size of the guide channel (10) and the corresponding rod diameter.

4. The bar feeder (1) according to claim 3, wherein the clamping device (3) further comprises an actuating piston (31), which acts on a drive cam (33) for the rollers (34).

5. The bar feeder (1) according to claim 4, wherein the driving cam (33) is provided with a plurality of actuating grooves (332) which cooperate with corresponding driving pins (341) provided on each roller (34).

6. A bar feeder (1) according to any one of claims 3 to 5, wherein the number of rollers (34) of the clamping device (3) is an even number, and the driving cams (33) of the rollers (34) are configured to drive half of the rollers (34) to rotate along a first rotation direction (S1), and to drive the other half of the rollers to rotate along a second rotation direction (S2) opposite to the first rotation direction (S1).

7. The bar feeder (1) according to any one of claims 1 to 5, wherein the device (2) for adjusting the diameter of the guide channel further comprises an integrally formed height adjustment system (4).

8. The rod feeder (1) according to claim 2, wherein the device (2) for adjusting the diameter of the guide channel further comprises an integrally formed height adjustment system (4), and the clamping device (3) comprises at least three rollers (34) and is configured to jointly constitute the height adjustment system (4).

9. The bar feeder (1) according to any one of claims 1 to 5, wherein the guide channel (10) is further provided with a fixing pin (5) which is inserted into the bottom of the flexible guide housing (11).

10. The bar feeder (1) according to any one of claims 1 to 5, wherein the angular sector is comprised between 60 and 90 degrees, the upper opening (11D) of the flexible guide housing (11) in the angular sector corresponding to the maximum bar diameter (D Max ) extends from the first position (P1).

11. The bar feeder (1) according to any one of claims 1 to 5, wherein the maximum bar diameter (D Max ) and the minimum rod diameter (D Min ) corresponds to a range of approximately 20 mm, and an additional guide insert (111) can be inserted into the flexible guide housing to define a new range of minimum and maximum diameters.

12. The bar feeder (1) according to any one of claims 1 to 5, wherein the upper opening (11D) of the flexible guide housing (11) further has a profile that allows mutual locking.

13. The bar feeder (1) according to claim 12, wherein the profile of the upper opening (11D) of the flexible guide housing (11) is a corrugated profile (11E).

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