GB1593119A - Method of producing sections of rod with variably preselectable length from individual rods without waste - Google Patents

Description

(54) METHOD OF PRODUCING SECTIONS OF ROD WITH VARIABLY PRESELECTABLE LENGTH FROM INDIVIDUAL RODS, WITHOUT WASTE (71) We, MEYER, ROTH & PASTOR MASCHINENFABRIK GmbH, a joint stock company organised under the laws of Germany, of Raderberger Str. 202, D-5000 Kbln 51, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a method for producing rod sections of variably preselectable length from individual rods, without leaving waste pieces, the individual rods being supplied in bundles of constant length.

For producing structural steel reinforcements for concrete buildings, methods have been adopted allowing mechanisation and automation of the production of such reinforcements. For such a purpose it is necessary in accordance with a given programme for rod sections to be available in accordance with the progress of construction in suitable lengths and in a given sequence. Since the lengths required in particular cases fluctuate, it is substantially impossible to keep all the individual length sections in store and to take them out in accordance with the given programme when producing reinforcements, especially since the individual lengths and the combinations thereof may vary to a considerable extent from one order to the next.

A further problem is that the rods are supplied exclusively in bundles with a given length, of for example 14 m. and not as a continuous length on a reel. Now, if the desired varying length rod sections were to be produced from the individual rods in accordance with a preset programme, considerable quantities of waste pieces would be unavoidable, which would be of use afterwards only as scrap.

We have sought to provide a method by means of which it is possible to produce rod sections with varying preselectablelengthsfrom individual rods without producing waste pieces. According to the present invention this is achieved by welding individual rods to one another to form a continuous rod length, guiding the continuous rod length for intermediate storage in a loop with a variable length and straightening the continuous rod length in a manner known per se and, by means of a cutting-to-length apparatus provided with a length measuring device, severing the desired length of rod section from the continuous rod length.

The use of this method avoids any waste pieces since in spite of the starting material being supplied in the form of individual rods of a constant length, the desired rod sections can be produced from a continuous and substantially "endless" rod length. By guiding the continuous rod length in an intermediate storage loop between the welding on the one hand and the cutting-to-length on the other hand it is possible without influencing these two functions to arrange for the welding operation to be carried out at a constant rhythm and the cutting-to-length operation to be carried out at a rhythm fluctuating because of the fluctuating lengths of the rod sections needed. Since the individual rods are sufficiently straightened, the rod does not need to be straightened if the bending of the continuous length produced from the individual rods in the intermediate storage loop does not exceed the elastic limit of the material.

In a further development of the method of the present invention it is also proposed that an individual rod to be welded is singled out from a bundle by drawing it out in the longitudinal direction, transporting it in the transverse direction, and then welding it to the end of the continuous rod length. This method step makes it possible for each individual rod to be welded to be taken up only by one end by means of a suitable device and isolated from the bundle from which it is removed so that only one individual rod at a time is reliably supplied to the welding station.

According to a further advantageous feature of the invention it is proposed that the continuous rod length passes through controllable driving apparatus which are situated one upstream and one downstream of the intermediate storage loop in the direction of continuous rod length travel, the transporting work carried out by the two driving apparatus being controlled independently of one an other. It is particularly advantageous if the transporting action of the driving apparatus situated upstream of the intermediate storage loop is controlled by the welding apparatus and the transporting action of the driving apparatus situated downstream of the intermediate storage loop is controlled by the cutting-to-length or severing apparatus. As a result, in spite of the fact that there is a continuous unbroken rod length between the welding station on the one hand and the cutting-to-length apparatus on the other hand the continuous rod length can be transported in an independent manner associated with the particular working station.

The different rod lengths between these two working stations, resulting because of the different welding rhythms on the one hand and the varying speed of conveying in the region of the cutting-to-length apparatus on the other hand are taken up by the intermediate storage loop. It is simply a matter of ensuring that the fastest speed of removal at the cutting-to-length apparatus side on the whole neither goes below or above the rate of individual rod supply at the welding apparatus side.

According to an advantageous further feature of the invention the maximum and minimum allowable sizes of the intermediate storage loop are ascertained respectively and the cutting-to-length operation is discontinued when the minimum length is reached, and the welding operation is discontinued when the maximum size is reached. Conveniently this is controlled so that the operation continues without further interruption after the maximum or minimum situation has been eliminated.

Preferably, in the first instance at least two individual rods are welded to one another in a first welding operation and the multiple length thus produced is transported in the transverse direction and welded in a second welding operation to a previously welded rod length. By this measure it is possible to achieve very short cycle times for the cuttingto-length operation, although the welding operation with all the necessary transporting and processing operations such as for example positioning, welding, removing burrs and finally transporting away the multiple length from the first welding station requires a minimum time to complete because of the physical circumstances. Since two welding operations can be carried out substantially, at the same time namely the first welding operation for producing the multiple length and the second welding operation for attaching the multiple length by welding to a previously welded rod length, the throughput in this region can be considerably increased.

According to an advantageous feature of the invention in this connection the individual rods to be welded to form a multiple length are in each case taken out separately from separate bundles of rods. This has the advantage that the singling-out operation for the rods which are to be welded to one another can be effected simultaneously or at least at short intervals behind one another, so that no considerable loss of time results.

The present invention is further illustrated in the accompanying drawing which shows an installation for carrying out the method of the present invention. The individual rods supplied for processing in bundles 1, 2 are deposited on suitable reception means 3, 4, and the bundles are opened. On one longitudinal side of the two reception means 3, 4 there is situated, above, a rail 5 on which a gripping device 6 is arranged to be capable of moving to and fro in the direction of the double arrow 7. By means of this gripping device an end of an individual rod is gripped in each case in the region of the station A and B respectively of the bundles 1 and 2 respectively, lifted and then singled out from the bundle by moving in the longitudinal direction. The rod drawn out of the bundle 1 is then lying on a transverse transporting arrangement 8 at the longitudinal side of the reception means 4, and a rod taken out from the bundle 2 on a transverse transporting arrangement 81 at the longitudinal side of the reception means 3.

The transverse transporting arrangements 8, 81 transport the two individual rods 9, 9 in a transverse direction to abutments 10, and the ends which face towards one another are introduced into a welding apparatus 11 which operates for example on the flash butt welding principle or by an upset butt welding method.

After the two individual rods 9, 9l have been welded to form a multiple length, the latter is transported away over the abutments 10 by means of the transverse transporting arrangements 12, 12l and transported as far as the abutments 13, the free end C of the multiple length being introduced into a second welding apparatus 14. In the welding apparatus 14 the multiple length is welded to the end of the rod length produced at the previous working cycle, in the same way as before. The welding region has any burrs removed in the usual way at both welding operations.

As soon as the welding operation is finished, a driving apparatus 15 is actuated by way of the welding apparatus 14, and the rod length produced is transported away in the direction of the arrow 16, so that the abutments 13 are released to receive a new multiple length. Transporting is continued until the free end D of the continuous rod length now produced is in the welding position in the welding apparatus 14.

The continuous rod length is guided in the form of an intermediate loop 17 which in accordance with the different working cycles at the welding side on the one hand and the cutting-to-length side of the other hand can fluctuate between a maximum size predetermined by a suitable sensor 18 and a minimum size preset by a sensor 19.

The continuous rod length is transported by a further driving apparatus 20 which introduces the continuous rod length by way of a straightening apparatus 21 of known construction into a cutting-to-length apparatus provided with a shears 22 and with a length measuring device 23.

The length measuring device 23 is so equipped that by means of a programme control unit 24 the sequence of the desired lengths is adjusted by means of a suitable control element 25, and when the free front end of the continuous rod length reaches the measuring point set in each particular case (shown diagrammatically here by suitable transverse lines 26) the shears 22 is automatically actuated and the severed length is thrown out in the direction of the arrow 27.

The sensor 18 associated with the intermediate storage loop 17 is connected with the driving apparatus 15 so that when the maximum size is reached the further transporting of the continuous rod length is discontinued.

Accordingly the sensor 19 is connected with the driving apparatus 20 so that when a minimum size of intermediate storage loop 17 is reached the cutting-to-length operat;on is discontinued until there is again a sufficient rod length available in the intermediate storage loop.

WHAT WE CLAIM IS: 1. A method of producing rod sections of variably preselectable length from individual rods of constant length supplied in bundles, which comprises welding together individual rods to form a continuous rod length, guiding the continuous rod length for intermediate storage in a loop with a variable length, straightening the continuous rod length and cutting rod sections of preselected length from the continuous rod length by means of a cutting-to-length apparatus provided with a length measuring device.

2. A method as claimed in claim 1, wherein an individual rod to be welded is removed from a bundle of such rods by drawing out in the longitudinal direction of the bundle, conveyed in the transverse direction and then welded to the end of the continuous rod length.

3. A method as claimed in claim 1 or 2, wherein the continuous rod length passes through controllable driving apparatus which are situated one upstream and one downstream of the intermediate storage loop in the direction of travel of the continuous rod length, the transporting being controlled by the two driving apparatus independently of one another.

4. A method as claimed in claim 3, wherein the transporting action of the driving apparatus situated upstream of the intermediate storage loop is controlled by the welding apparatus and the transporting action of the driving apparatus situated downstream of the intermediate storage loop is controlled by the cutting-to-length apparatus.

5. A method as claimed in any one of claims 1 to 4, wherein the maximum and minimum allowable sizes of the intermediate storage loop are ascertained and when the minimum size is reached the cutting-to-length operation is discontinued and when the maximum size is reached the welding operation is discontinued.

6. A method as claimed in any one of claims 1 to 5, wherein in the first instance at least two individual rods are welded to one another in a first welding operation and the multiple length thus produced is transported in the transverse direction and welded in a second welding operation to a previously welded rod length.

7. A method as claimed in claim 6, wherein the individual rods which are to be welded to form a multiple length are each singled out from a separate bundle.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. accordance with the different working cycles at the welding side on the one hand and the cutting-to-length side of the other hand can fluctuate between a maximum size predetermined by a suitable sensor 18 and a minimum size preset by a sensor 19. The continuous rod length is transported by a further driving apparatus 20 which introduces the continuous rod length by way of a straightening apparatus 21 of known construction into a cutting-to-length apparatus provided with a shears 22 and with a length measuring device 23. The length measuring device 23 is so equipped that by means of a programme control unit 24 the sequence of the desired lengths is adjusted by means of a suitable control element 25, and when the free front end of the continuous rod length reaches the measuring point set in each particular case (shown diagrammatically here by suitable transverse lines 26) the shears 22 is automatically actuated and the severed length is thrown out in the direction of the arrow 27. The sensor 18 associated with the intermediate storage loop 17 is connected with the driving apparatus 15 so that when the maximum size is reached the further transporting of the continuous rod length is discontinued. Accordingly the sensor 19 is connected with the driving apparatus 20 so that when a minimum size of intermediate storage loop 17 is reached the cutting-to-length operat;on is discontinued until there is again a sufficient rod length available in the intermediate storage loop. WHAT WE CLAIM IS:

1. A method of producing rod sections of variably preselectable length from individual rods of constant length supplied in bundles, which comprises welding together individual rods to form a continuous rod length, guiding the continuous rod length for intermediate storage in a loop with a variable length, straightening the continuous rod length and cutting rod sections of preselected length from the continuous rod length by means of a cutting-to-length apparatus provided with a length measuring device.

2. A method as claimed in claim 1, wherein an individual rod to be welded is removed from a bundle of such rods by drawing out in the longitudinal direction of the bundle, conveyed in the transverse direction and then welded to the end of the continuous rod length.

3. A method as claimed in claim 1 or 2, wherein the continuous rod length passes through controllable driving apparatus which are situated one upstream and one downstream of the intermediate storage loop in the direction of travel of the continuous rod length, the transporting being controlled by the two driving apparatus independently of one another.

4. A method as claimed in claim 3, wherein the transporting action of the driving apparatus situated upstream of the intermediate storage loop is controlled by the welding apparatus and the transporting action of the driving apparatus situated downstream of the intermediate storage loop is controlled by the cutting-to-length apparatus.

5. A method as claimed in any one of claims 1 to 4, wherein the maximum and minimum allowable sizes of the intermediate storage loop are ascertained and when the minimum size is reached the cutting-to-length operation is discontinued and when the maximum size is reached the welding operation is discontinued.

6. A method as claimed in any one of claims 1 to 5, wherein in the first instance at least two individual rods are welded to one another in a first welding operation and the multiple length thus produced is transported in the transverse direction and welded in a second welding operation to a previously welded rod length.

7. A method as claimed in claim 6, wherein the individual rods which are to be welded to form a multiple length are each singled out from a separate bundle.