WO2009118143A2

WO2009118143A2 - Bending method and machine for metal rods and/or bars

Info

Publication number: WO2009118143A2
Application number: PCT/EP2009/002125
Authority: WO
Inventors: Ugo Milocco; Giovanni Fratti
Original assignee: N.G.F. Inzeniering D.O.O.
Priority date: 2008-03-25
Filing date: 2009-03-23
Publication date: 2009-10-01
Also published as: WO2009118143A3; EP2262596A2; WO2009118143A4; ITUD20080063A1

Abstract

The present invention relates to a bending method for metal rods and/or bars, starting from rods (15) or bars previously straightened in a rectilinear manner by appropriate means and fed in the form of segments and/or originating from coils of continuous wire, wherein the devices suitable for performing all the steps for gripping (12, 18), bending (10, 11, 19), cutting (14) and expulsion (13, 17) of the finished product (16) are mounted on a single carriage (9), which can slide on parallel guides (4), and are actuated and managed, in coordination and cooperation with each other, by automatic computerization systems. The present invention also relates to a machine for bending metallic bars and/or rods, wherein the machine includes means for gripping (12, 18), means for bending (10, 11, 19), means for cutting (14) and means for expulsion (13, 17) of the finished product (16), said means (12, 18; 10, 11 19; 14; 13, 17) being mounted on a single carriage (9), which can slide on parallel guides (4), and said means (12, 18; 10, 11 19; 14; 13, 17) being actuated and managed, in coordination and cooperation with each other, by automatic computerization systems.

Description

BENDING METHOD AND MACHINE FOR METAL RODS AND/OR BARS

Field of application

The present invention relates to the method for providing serial automatic bending operations, to be performed on metal bars or rods, and to the corresponding bending machine.

The invention is particularly useful and advantageous in the production of stirrups and/or bends on steel rods or bars used as reinforcement elements in concrete castings in the construction sector in general. The method is innovative in that it uses an appropriately provided carriage (or slider), which slides on appropriately provided guides and is equipped with all the devices needed to perform the bends, i. e.: a grip vise for positioning the rod, an abutment surface, a bending assembly and an assembly for cutting said bars. The innovation therefore consists in providing, on an appropriately provided carriage that can move on command, all the necessary devices suitable for bending, gripping and cutting the bar; said assembly is furthermore capable of bending the bar even during its motion in the positioning step.

All this allows to minimize the dimensions of the machine, also reducing the production costs of the individual devices because they are mounted on the movable carriage; it is highly competitive in the field of bar bending and in the formation of stirrups for the forming of lattice- like cages, lattice girders, in medium and small production runs.

Background art

In the background art, bending machines are known, in the production of metal bars or rods or in the formation of stirrups, which are used to create three-dimensional lattice-like cages and lattice girders and/or simply bent bars that are suitable to form lattice-like reinforcement structures in the building sector in general. These bent metal elements are usually used to reinforce concrete castings in buildings.

Bending machines and systems are known which use multiple separate assemblies to perform bends on the bars manually or automatically. These machines are very complex, because they use several separate operating assemblies, such as for example automatic grip clamps, bending pins mounted on rotating discs, blades of shears, located in various points of the machines, which interact on the bar in a programmed manner and separately.

Some assemblies are fixed or are rendered autonomously movable and can be positioned on command; others are completely movable and can slide on guides on command. These movements are managed by appropriately provided computerized systems. These machines, which have large dimensions and have substantial production costs, are designed for highly specialized productions and achieve countless possibilities to bend metal wires or rods, preferably made of steel with improved bonding.

Small-size bending machines for small production runs are also known, but they, too, have multiple separate operating assemblies which are actuated in sequence in order to bend the bars. Their individual operating assemblies are fixed on a working plane; only the bending pin, which is radial with respect to a central fixed pin, is turned in order to perform the desired angular bends. Said machines have at most the possibility to retract the bending pin with respect to the working plane in order to allow to perform bends clockwise and counterclockwise. Said automatic machines, despite being compact, have costs that do not allow their widespread diffusion among the operators in the field or even a commercial outlet, such as for example in specialized shops for the building sector and/or in simple hardware shops.

Therefore, the disadvantages, mostly of the economic type, observed in current bending machines for metallic wires, rods and/or bars are therefore evident.

Summary of the invention

The aim of the present invention is therefore to obviate the drawbacks of the background art, providing a method for performing bends on metallic wires or rods or bars that allows to build small bending machines that are characterized by low cost and therefore are accessible to multiple operators even in the general commercial sector.

Of course, the conceptual innovation that is used can be transferred and utilized also to manufacture higher-performance machines. The most evident features of the present invention are as follows:

- an automatic bending machine for metal wires and/or rods, preferably made of steel, which has small dimensions, is manageable with computerized systems, and has the main particularity of having a single assembly that can move on sliding guides, is moved on command by suitable actuation means, and is provided with automatic means for gripping the rod, bending means, cutting means and/or means for expelling the cut elements;

- the assembly that can move on sliding guides performs all the functions of bending machines and is actuated on command with respect to the rod, and at the same time can grip the rod to be bent and position it along the guides and, during said movement, can simultaneously bend it with the programmed dimensions and angles;

- bending performed simultaneously with rod positioning allows a considerable time saving, which is more substantial if it is necessary to perform multiple bends on the same element; - the movable carriage provided with a particular bending pin shaped like a contoured finger, which accompanies in its rotation the first portion of the rod in bending, improving the quality of the execution of the bend and complying to the fullest extent with the programmed parameters;

- the possibility to perform bends clockwise and/or counterclockwise by providing the machine with a bending finger (or even more than one);

- the possibility to perform successive bends on the rods in order to provide elements that are bent according to geometric closed or open shapes.

Summary of the invention

The aim and objects of the invention are achieved according to the features of the main claim and/or of any other claim cited in this patent text, by providing a method and the corresponding bending machine for producing stirrups obtained from rods that are variously bent and/or shaped in a completely automatic manner, managed by computerized means, by means of a single movable assembly that can slide along appropriately provided guides and is equipped with all the devices suitable for gripping and positioning the wire and/or the rod, its single or multiple bending, by the desired extent both in terms of length and angularly, its shearing and the automatic expulsion of the product thus bent. ^

The method for programmed bending of metal bars or rods is based essentially on the use of at least one movable assembly provided with all the devices that are suitable for the operations for performing bends to size and for cutting and expelling or evacuating the bent product. Said assembly, which can slide along appropriately provided guides, has a sufficiently broad stroke range, which is suitable first of all to pick up from a specific region the rod (which can be provided in the form of straight bars or as a result of the straightening of coils), gripping it and moving it to another suitable region of the machine that allows to facilitate its subsequent programmed bendings.

The innovative core of the present invention resides in that during the movement of the rod, the bending assembly performs simultaneously the programmed bending, and when it reaches the working region it is already ready to perform the subsequent steps in sequence. This is advantageous with respect to known machines and methods, since it saves time (the time related to the bending step is eliminated, since it is included in the time for moving into position the bending assembly to perform the subsequent programmed bending operations).

According to a preferred solution of the invention, which however is non-limiting, the bending assembly comprises a vise with automatic opening and closing, which is actuated and managed in a computerized manner. It is designed to open on command and allow the passage of -A - the straight rod between its jaws and to close gripping it in the exact linear position, leaving it to protrude from the opposite side with respect to the inlet where the bending pin or contoured bending finger works. Another peculiarity of the automatic vise consists in that the side where the bending of the metallic rod occurs is inclined with an angle of less than 90° with respect to the axis of advancement of the rod (in plan view), in order to allow bendings of the rods with angles of more than 90°. Furthermore, this hypothetical edge between the portion of the straight jaws that can open automatically and said inclined side is radiused so as to constitute a fixed bending surface (which in other similar machines is instead formed by an actual fixed pin, which protrudes at right angles from the working plane or can move along its own axis or with respect to other axes of rotation).

Again with reference to said fixed bending point, a particular bending element cooperates with it in coordination and at an appropriate fixed or adjustable distance and is shaped like a slotted finger, which is pivoted at one end and is capable of providing a lever arm with angular movement in order to perform a bending action on the rod to be bent. Said bending finger has, on its active side, a transverse cross-section shaped like a semicircle and/or similar shapes, in order to facilitate the sliding of the rod during the movement of the device supporting carriage and also during bending operations by guiding the rod in the correct manner.

A further peculiarity of the movable bending assembly relates to the fact that it has, in addition to the vise and the bending pin, also a device for automatic cutting at right angles to the straight jaws of the vise with mutually opposite blades that are actuated automatically once bending operations on the rod have been completed.

In a further variation, the movable bending assembly can be provided with an automatic lever system for the expulsion of the rod or of the product from the grip vise, in order to release it once work has ended after the step for cutting the rod, thus preparing it free and ready for a new work cycle.

As is evident from the description, the movable bending assembly for metallic rods or wires or bars can slide on guides and works as follows: it moves on command, passing from the initial position to the station for picking up the rod of the rectilinear type (arranged thereat by other known devices which are not part of the present invention), in which the open vise causes said rod to slide until it reaches a programmed distance in the longitudinal direction; here the jaws are closed automatically and the assembly moves along the guides, drawing the gripped rod and simultaneously performing the first bending of the protruding end of the rod; once the operating region (suitable for the bending operations to be performed) has been reached, the vise opens and the bending finger with angular rotation returns to its initial position, i. e., coaxial and parallel to the jaws of the vise (in the meantime, the rod is kept in position by the feeder assembly), in order to allow the longitudinal movement of the entire assembly along said rod until it reaches the programmed position; at this point, the vise closes on command and the bending finger produces the bend with the desired angle; other bending operations occur subsequently, until the desired product is obtained; at this point, the automatic cutting assembly, arranged at right angles to the seats of the jaws of the vise and mounted on the same movable carriage, intervenes and cuts the rod to size; there is also an optional expulsion device of the rocker lever type in order to free the the open vise once the action for shearing the rod when the product is finished has been performed.

According to a variation to the present invention, it is possible to equip the carriage with a bending pin or an angular bending finger that is contoured and devised to perform bends clockwise and/or counter clockwise.

The bending method and the corresponding bending machine are particularly suitable for small or medium production runs of elements obtained by bending rods according to various geometric shapes, open or closed figures, regular or irregular figures, such as for example stirrups suitable for the manual construction of three-dimensional lattice girders or cages for reinforcing concrete castings in the building sector.

Brief description of drawings

An embodiment according to the present invention is shown by way of preferred but non-limiting example in the accompanying drawings, wherein:

Figure 1 is a plan view of an automatic machine for bending rods according to the prior art, provided with the various devices needed to perform bends on the rod which are mounted on various movable carriages, a bending assembly and a grip vise assembly, and/or in fixed position of the cutting assembly;

Figure 2 is a plan view of the movable bending assembly which comprises on the same carriage the grip vise with automatic opening and closing, the automatic bending finger with angular bending movement with respect to the edge of the vise, the cutting assembly and the assembly for expelling the cut rod of the lever and rocker type;

Figure 3 is a side view of the movable assembly according to the preceding figure, highlighting the limited space occupation of the single device supporting carriage;

Figure 4 is a transverse side view of the assembly shown in Figures 2 and 3, highlighting the automatic rod expulsion device of the rocker lever type;

Figure 5 is a schematic sequential plan view of the bending machine with a single movable carriage that supports the multiple devices suitable for the automatic bending operations, such as: vise, bending finger, shears and rod ejector. The example relates to the execution of a square stirrup starting from a straight metal rod. The carriage is in the initial position with the vise having open jaws and with the bending finger arranged parallel to said jaws, while the straight metal rod is spaced and arranged coaxially with respect to said jaws;

Figure 6 is a plan view of the second sequence, i. e., the automatic positioning of the carriage in a longitudinal direction with respect to the initial rod: here the vise closes automatically and firmly grips the rod to be bent;

Figure 7 is a plan view of the third sequence, in which the carriage, in its movement for positioning in the operating region, drags the rod and simultaneously performs the first bending operation;

Figure 8 is a plan view of the fourth sequence, in which the movable carriage reaches the operating region and in the meantime the bending finger has repositioned itself parallel to the rod and to the jaws and the vise is open;

Figure 9 is a plan view of the fifth sequence, in which the carriage moves on command along the rod, which is kept stationary by known means: once the desired position has been reached, the vise closes;

Figure 10 is a plan view of the sixth sequence, i. e., of the second bending at 90° of the rod and of the forward movement of the carriage, drawing back said rod;

Figure 11 is a plan view of the seventh sequence, i. e., of the opening of the vise and of the idle repositioning of the bending finger;

Figure 12 is a plan view of the eighth sequence, i. e., of the positioning of the device supporting carriage at a selected distance with respect to the stationary rod, the vise closing automatically once said distance has been reached;

Figure 13 is a plan view of the ninth sequence, i. e., of the forward movement of the carriage, drawing the material and at the same time performing the third bending of the square stirrup;

Figure 14 is a plan view of the tenth sequence, i. e., of the opening of the vise and of the rotation in the free position of the bending finger;

Figure 15 is a plan view of the final step, i. e., of the positioning of the device supporting carriage in an ideal position along the straight portion in order to cut to size said rod and expel the finished square bracket.

As can be seen from the various figures, the bending method uses a bending machine that has at least one movable carriage 9 that can slide on command along sliding guides 4 and is equipped with all the devices needed to perform automatic bending on a rod 15, i. e.: a vise 12 with automatic opening and closing, a bending pin or finger 10 actuated in an angular manner with respect to the hinge axis 11 in order to perform the bending of the metal rods, a pair of blades 14 for cutting the rod and an automatic device 13 for expelling the rod once the operations for bending and cutting the product have been completed.

Figure 1 illustrates a solution that is known in the specific field (prior art), in which the various essential devices for performing bending and cutting of the rods 1 are arranged on clearly distinct and separate assemblies or elements and there is a static straightening assembly with rollers 2 which ends with a fixed cutting assembly 3 at right angles to the advancement direction of said rod. The machine is provided with sliding guides 4 on which the bending assembly 5 and the clamp or vise 6 for gripping the rod slide independently and on command. These operating assemblies are synchronized and managed by way of a network 7 for connection to the data- processing system 8. This technical solution is very expensive indeed because it has several mutually separate assemblies that are mounted on separate carriages, and therefore the production costs are justified only for large production runs and is disadvantageous in the case of small and medium production runs.

Figures 2, 3 and 4 therefore illustrate, in various views and in a simplified manner, the subject of the present invention, highlighting the fundamental differences with respect to the background art. The invention is convenient and advantageous indeed because of the fact that the individual assemblies are simplified (in their number) and are concentrated on a single carriage 9, which can slide on two parallel guides 4, being actuated by known computerized systems that manage appropriately provided actuators to perform all the operating steps in an automatic and programmed manner.

The carriage 9 has a particular grip vise 12, with a fixed reference portion 18, works with the jaws arranged parallel and in a longitudinal direction, like the sliding guides 4 and like the feed direction of the rod 15. Said vise has a radiused edge, proximate to the pivoting axis 11 of the bending finger 10 and on the opposite side with respect to the one from which the rod 15 arrives, which acts as a fixed surface for bending the rod.

The side of said vise is contoured with an acute angle with respect to said pivoting axis 11, in order to be able to form bends of the rod of more than 90°. Both the surfaces of the jaws of the vise and the bending finger 10 are contoured with a receptacle, for example having a semicircular transverse cross-section. The bending finger 10 pivoted at 11, actuated by the lower portion of the slider with an appropriately provided lever 19 on command, can perform an angular rotation, producing bends on the rod with angles from 0° to more than 90° (for example up to 120°).

Also proximate to the vise 12, on the opposite side there is the cutting assembly provided with two mutually opposite blades 14, which are actuated automatically on command when the rod is cut. Said blades are arranged at right angles to the feed direction of the rod 15. An automatically actuated rocker lever 13 is mounted on a pivoting axis 17 on the same side of the vise 12 and is designed to extract and expel the rod of the completed stirrup once it has been cut, from the jaws of said vise.

For the sake of greater efficiency, the working plane of the machine is inclined with an angle that is close to vertical so as to facilitate evacuation of the finished stirrup 16 by gravity.

The subsequent figures, as already described in the presentation, exemplify a possible succession of automatic sequences for producing a stirrup with a square shape.

As is evident, the method of operation and the bending machine proper are very different and innovative with respect to current knowledge in the specific field of application, providing considerable advantages especially in construction from an economic standpoint, thus providing an automatic bending machine for small and medium production runs which is within the reach of a larger number of users and can be distributed also in shops and specialized centers.

Of course, the invention is not limited to the example of embodiment described above, starting from which it is possible to provide other embodiments and other forms, and the details of execution may in any case vary without thereby abandoning the essence of the invention as stated and claimed hereinafter.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs

Claims

1. A bending method for metal rods and/or bars, starting from rods (15) or bars previously straightened in a rectilinear manner by appropriate means and fed in the form of segments and/or originating from coils of continuous wire, characterized in that the devices suitable for performing all the steps for gripping (12, 18), bending (10, 11, 19), cutting (14) and expulsion (13, 17) of the finished product (16) are mounted on a single carriage (9), which can slide on parallel guides (4), and are actuated and managed, in coordination and cooperation with each other, by automatic computerization systems.

2. The method according to claim 1, characterized in that during the movement of the carriage (9) along the sliding guides (4), with the grip vise (12, 18) in the closed position (in the presence of a clamped rod), it is possible to perform the simultaneous bending, through the desired angle, of said rod (15).

3. The method according to claims 1 and 2, characterized in that the movable carriage that can slide on guides is provided with a grip vise (12, 18), with an angular bending finger or pin (10, 11, 19), and with an automatic cutting assembly.

4. An automatic machine for bending metallic bars and/or rods that originate from suitable feeder means in rectilinear segments or from rods obtained from the straightening of coils, characterized in that it is provided with at least one movable carriage (9) that can slide on parallel guides (4) in a longitudinal direction in a manner similar to the direction of origin of said rod (15) and is provided on the working plane with: a grip clamp or vise (12, 18) with automatic opening and closing, which has at least one end edge of the jaws whose shape is radiused to act as a fixed bending surface; a bending finger (10), which is pivoted at (11) and is actuated by means of a lower lever (19) and is capable of performing an angular rotation from 0° to more than 120° (clockwise or counter clockwise); with a cutting assembly with mutually opposite blades (14); and/or with an automatic assembly for expelling the previously cut rod.

5. The bending machine according to claim 4, characterized in that in an opposite position with respect to the radiused edge of the vise (12, 18), acting as a fixed bending surface, there is the bending finger (10), which is pivoted on an axis (11) and is fixed or adjustable with respect to said surface and is jointly connected to the underlying actuation lever (19) and is capable of performing angular rotations from 0° to more than 120° on the rod (15), clockwise and/or counter clockwise with suitable technical modifications.

6. The bending machine according to claims 4 and 5, characterized in that the radiused edge of the vise and the pivoting axis (11) of the bending finger (10) are perpendicular to the working plane.

7. The bending machine according to claims 4-6, characterized in that the clamp has a side that is contoured with an acute angle and is contiguous to the radiused edge that acts as a fixed surface for bending and abutment.

8. The bending machine according to claims 4-7, characterized in that it has a sectional contour that is shaped like a semicircle or circular arc or another contour suitable for the purpose in order to facilitate the sliding of the rod both on the bending finger (10) and on both jaws of the vise, the movable one (12) and the fixed one (18), and/or only in one of the two.

9. The bending machine according to claims 4-8, characterized in that the vise (12) has, on the side that is perpendicular to the jaws and lies opposite the contoured side, a device for ejecting the rod from the jaws with a fulcrum at (17) of a rocker lever (13) or another equivalent means suitable for the purpose.

10. The bending machine according to claims 4-9, characterized in that proximate to the vise (12), at right angles to the feed direction of the rod (15) and on the same origin side, there is the cutting assembly with mutually opposite blades (14).

11. An automatic machine for bending metallic bars and/or rods that originate from suitable feeder means in rectilinear segments or from rods obtained from the straightening of coils, wherein the machine includes means for gripping (12, 18), means for bending (10, 11, 19), means for cutting (14) and means for expulsion (13, 17) of the finished product (16), said means (12, 18; 10, 11 19; 14; 13, 17) being mounted on a single carriage (9), which can slide on parallel guides (4), and said means (12, 18; 10, 11 19; 14; 13, 17) being actuated and managed, in coordination and cooperation with each other, by automatic computerization systems.