WO2018154549A2 - Manual reinforcement steel bending machine - Google Patents

Abstract

The present invention refers to a support and reference table and to a manual tool for bending steel bars. The geometrical design of the table and the stops is suitable for them to be placed at any required distance. The manual tool is designed for providing for an easier access to the bar even in cases with little space being available at the sides thereof. For manufacturing one type of pieces the stops are placed on the table in such a way that these allow making all the bends the piece requires without having to remove it from the table. After all the bending has finished, the piece is removed and the following bar is placed to proceed with the next piece.

Description

MANUAL REINFORCEMENT STEEL BENDING MACHINE

OBJECT OF THE INVENTION The present invention may be included in the technical field of bars, profiles or tubes bending onto a fixed forming element, as well as bending being specially adapted for manufacturing reinforcement elements for concrete, and it particularly refers to a device for the application of a bending moment to a reinforcement steel bar, said device comprising a fixing table and a plurality of levers that can be linked to the table so as to proceed with the bending onto the steel bars.

BACKGROUND OF THE INVENTION

Building reinforced concrete structures requires pieces to be made using reinforced steel bars with several shapes that require bending thereof. Making said pieces may be difficult depending on the piece geometry.

In order to provide for easier manufacture of these pieces several patents have been disclosed. For example, patent number US3661002 discloses a steel bending machine that uses a rotating disc having electric control means; use thereof may be difficult regarding complex pieces. Additionally, in this equipment, the operator must move the piece after each bend is made.

On the other hand, patent US4292834 discloses a bending table where it is easy to configure varying supporting positions for performing the bending, which could potentially be adapted in such a way that it is not required to move the piece after each bending action. However, this system does not provide any restriction to the parts next to the bending point that may contribute to the straight shape of the bar in sections where this is required, considering that when bending the bar at one point said bar will also tend to bend, although to a lower extent, in areas being adjacent to that of the bend.

Additionally, the bending tool disclosed in this patent is a tube, which does not allow the perfect contact between the bar and the table when the tool is installed in the bar, since, as the tube is surrounding the bar, a separation between the bar and the table will always remain that is similar or higher than the thickness of the tube wall.

This limitation may be unfavourable considering that what is intended is to avoid deviations of the bar outside the table plane to the maximum, a target which is easier to attain if there is the possibility of placing the bar in its plane once each bend is finished, especially if it can be placed in said position using the bending tool.

Patent US6128944 discloses a drilled surface into which levers are anchored for exerting a force onto the reinforcement bar and thus bending it. The use of this patent may have limitations in terms of the relative position of the bend in a bar when more than one bend per bar is required, since the position of the points of supports for bending pins and levers are restricted to exactly match with a series of predefined holes in the anchoring table.

Another difficulty that may arise is that force is applied through an isolated contact point, thereby a supporting surface is not provided that may be used for forcing the straight shape of the bar in sections that must remain so. Additionally, for bends where there is little space between two "legs" of the piece, it will not be possible to place the pushing member disclosed in this patent due to lack of space.

DESCRIPTION OF THE INVENTION

The present invention refers to a manual device for bending reinforcement steel bars, preferably of the type being intended to be inserted inside concrete structures, said device comprising a support and reference table and a manual lever-like tool for bending steel bars by applying a bending force.

The design of the table and stops is suitable for the bars to be placed at any required distance. The manual tool is designed for providing for easier access to the bar even in cases with little space being available at the sides thereof. For manufacturing one type of pieces the stops are placed in the table in such a way that these allow performing all the bends the piece requires. Placing the stops consists of locating them at the upper part as it may be necessary for the position of the bent bar to match, at each bend starting point, with one of the slots of each stop. After placing the stop upper pieces, the lower part of the stops must be placed underneath the grid of the bending table, and the screws attaching the lower and upper part of the stops must also be placed. Then, the screws will be given the necessary torque for preventing sliding thereof during the bar bending. It is advisable to also use a stop as a guide for the initial location of the unbent bar, so as to facilitate the process and thus increase production.

In order to perform the bending, the bar is located at the initial position and all the bends are made using the lever. The lever is placed in such a way that the short claw thereof is positioned at the inner side of the bend. Upon rotating the bar, the lever path will be interrupted by the stops, thereby being necessary to incline the lever upwardly enough so as continue bending the bar, thus avoiding the obstacle represented by the stop, and lower it down again for placing it in the slot of the corresponding stop. When finishing all the bends the piece is removed and the next bar is placed so as to make the following piece. During the bending, it has to be taken into account that the bar elasticity will tend to undo the bends being made, so the bending angle must be exceeded until, when returning, it coincides with the intended final position. The points which the bend must reach may be marked in the bending table so as to provide for a reference. In order to promote friction, and thus provide for an easier use of this invention, it is necessary that the contact surfaces between the lever and the bar, and those between the stops and the grid of the bending table, are provided with rugosity.

The separation between the stop bolts must be calculated based on the grid dimensions, such that the stops can be placed at any position onto the grid, without said grid occluding all the bolts, and at least two bolts can be placed. This is achieved by providing multiple threaded orifices at the stop and specifying that the thickness of the grid solid portion is lower than the width of the orifices thereof; the exact design basically requires the minimum distance between the bolts to be specified, based on an analysis of the grid geometry.

The dimensions of the bolts, stops, supporting grid, and frame of the bending table must be selected trying to obtain robustness and rigidity of the system. The stop slots and the bending lever dimensions must be in accordance with the dimension of the bar to be bent, so a set of stops and lever will be required for each bar size to be bent on the table being disclosed. DESCRIPTION OF THE DRAWINGS

To implement the present description being made and in order to provide a better understanding of the characteristics of the invention, according to a preferred practical embodiment thereof, a set of drawings is attached as part of this description, with an illustrative but not limitative purpose, which represents the following:

Figure 1 .- It shows a top plan view of the manual bending machine object of the invention.

Figure 2.- It shows a front view of the bending machine table.

Figure 3.- It shows a side view of one of the levers of the bending machine.

Figure 4.- It shows a plan view of one of the levers of the bending machine. Figure 5.- It shows a detailed schematic view of the attachment of one of the stops to the bending machine table.

Figure 6.- it shows a plan view of a first bending process.

Figure 7.- It shows a plan view of a second bending process. PREFERRED EMBODIMENT OF THE INVENTION

The following is a detailed explanation, with the help of the figures referred to above, of a preferred exemplary embodiment of the object of the present invention.

The manual reinforcement steel bending machine, shown in figure 1 , comprises a support and reference table (1 ), a plurality of stops (2) being temporarily attachable to the table (1 ) for fastening a steel bar (3), and a lever (4) for manual bending of the bar (3) held by the stops (2) on the table (1 ).

As it is illustrated in figures 1 and 2, the table (1 ) comprises a perimetral supporting frame (5), a supporting gridded surface (6), which in this embodiment has an essentially parallelepiped geometry, and legs (7) for support and elevation over the ground plane.

Figure 5 shows how each of the stops (2) is temporarily attached to the gridded surface (6) of the support table (1 ) for fastening the bar (3), for which each stop (2) has in turn fastening elements (8), which in this preferred embodiment are threaded screws. The lever (4) is formed by a body of an essentially elongated geometry, as it is illustrated in figures 3 and 4, which in turn has a first end (9) covered by a gripping rough surface (10), and a second end (1 1 ), from which long projections (12) and short projections (13) start, facing each other for coupling between them the bar (3) to be bent.

Figures 6 and 7 show, in a plan view, two sequences of a bar (3) bending process, in two opposite directions.

Claims

1 . Reinforcement steel manual bending machine comprising:

- a support and reference table, which in turn comprises:

- a perimetral supporting frame,

- legs for support and elevation over the ground plane, and

- a supporting gridded surface,

- a plurality of stops, temporarily attachable to the gridded surface of the support table by means of fastening elements for fastening a steel bar, and

- a lever for bending the bars held by the stops on the table, formed by a body of an essentially elongated geometry which in turn comprises:

- a first end covered by a rough gripping surface, and

- a second end, from which long projections and short projections start, facing each other for coupling the bar to be bent.

2. Manual bending machine according to claim 1 , where the support gridded surface of the table has an essentially parallelepiped geometry.

3. Manual bending machine according to claim 1 , where the fastening elements are threaded screws.