US3228220A - Method and apparatus for rolling an elongated metal body to form a profiled cross section - Google Patents

Description

' Jan. 11, 1966 E. scHNEcKENBURGl-:R 3,228,220 METHOD AND APPARATUS FOR ROLLING AN ELONGATED METAL BODY TO FORM A PROFILED CROSS SECTION 4 Sheets-Sheet 1 Filed NOV. 23, 1962 mm. @M xm. mk

' Jan. 11, 196e Filed Nov. 25, 1962 E. SCHNECKENBURGER METHOD AND APPARATUS FOR ROLLING AN ELONGATED METAL BODY TO FORM A PROFILED CROSS SECTION 4 Sheets-Sheet 2 INVENTOR ATTORNEYS Jan. 1l, 1966 E. SCHNECKENBURGER 3,228,220

METHOD AND APPARATUS FOR ROLLING AN ELONGATED METAL BODY FORM A PROFILED CROSS SECTION Filed Nov. 25, 1962 4 Sheets-Sheet I5 INVENTOR BY /M Myne/M ATTORNEYS Jan. 11, 1966 SCHNECKENBURG 3,228,220

METHOD AND APPAR S FOR ROLLING ELON A ED METAL BODY TO FORM A PROFILED C S SECTION Filed Nov. 25, 1962 4 Sheets-Sheet 4 'e s O w w m w INVENTOR fM/z cmfrfrfn/aae'e RL BY M @Myyjm ATTORNEYS United States Patent O 3,228,220 METHOD AND APPARATUS FR ROLLING AN ELUNGATED METAL BODY TO FURM A PRO- FELED CROSS SECTION Emil Schneckenhurger, Emmenbruck, Switzerland, assignor to Aktiengesellschaft der von MoosSchen Eisenwerke, Lucerne, Switzerland Filed Nov. 23, 1962, Ser. No. 239,595 Claims priority, application Germany, Nov. 2S, 1961, A 38,868 14 Claims. (Cl. 72-16) The essential difiiculty in rolling elongated metal bodies, such as rods and bars to form a desired profiled cross section, for example, an angle or channel section, consists in ensuring correct filling of the grooves in the rolls so that the section is fully formed `while maintaining the required dimensions within narrow limits, without forming fins. In order to comply with this requirement it has hitherto been customary to roll out sections in a plurality of passes, generally in from three to seven passes. By dividing the rolling work over a number of passes the reduction in the individual passes can be kept small and may be varied to permit distribution of the Work in any desired manner over the individual passes, while by suitably designing the rolls for the individual passes a determined ow ratio of the material can be ensured.

Apart from older three-high mills in which the grooves for the individual passes are distributed over the length of the rolls, the rolling out of sections in a number of passes, on the average ve passes, requires a rolling mill having a correspondingly large number of mill stands and a correspondingly large roll inventory. Thes-e roll stands are generally disposed as the last group in the line of a continuous mill train, so that during the period required for 1re-equipping this group all preceding mill stands also have to be stopped. It is true that heretofore a plurality of finishing mill groups operated in parallel have been allocated to the roughing groups and these finishing mill groups have been operated alternately in order to ensure extensive utilization of the roughing groups, but this entails greater expense for machinery. In addition, the rolling mill must be followed by auxiliary equipment, such as cooling means and straightening and stretching devices, capable of processing the production of the rolling mill immediately, unless special intermediate storage means are provided. Since however on the average only about to 15% of the production of a light rolling mill is constituted by profiled sections, the extensive auxiliary equipment the through-put of which is adapted to that of the rolling mill is poorly utilised. The rolling ymill itself can also not be fully utilised, since the delivery speed `of the mill stand is limited by the maximum delivery speed in the cooling bed, whereas the rolling mill would itself permit higher delivery speeds. The abovementioned disadvantages in the rolling out of sections have hitherto been accepted as unavoidable.

The invention proceeds from the fact that in hot rolling the temperature at which the material is rolled out eX- erts considerable influence on the flow conditions of the material in the roll gap in the usual rolling temperature range, because the higher the temperature at which the material is rolled, the greater the elongation and the smaller the widening of the material being rolled in the roll gap. As a result of the realisation by the inventor that the temperature at which the rolling is carried out can influence the filling of the roll grooves in the rolling out of sections, it is proposed according to the invention to regulate the temperature of the material being rolled in accordance with the degree of filling of the roll gaps in the rolling of sections in a single pass, the tempera- ICC ture of the incoming rolling stock being in particular reduced as the filling decreases. It has been found that the step according to the invention enables the flow conditions of the rolling stock in the roll gap to be influenced in such a manner that a single pass is sufficient to roll sections with clean shaping and good quality of material starting from a customary round, square, or rectangular cross-section and with a pass reduction dependent on the section to be produced, whereas hitherto it was thought that such `sections could be produced only in a plurality of passes.

Through the ability to roll sections in a single pass, the number of rolls required is reduced on the average by four rolls per section t-o be rolled, which in itself provides a substantial saving in cost, while the number of stand-by stands required is also reduced.

When rolling with a roll groove not completely filled (FIGURE l1), the raising and also the lowering of the temperature of the incoming rolling stock is controlled in accordance with the width of the outgoing rolling stock. If it is desired to work with a full roll groove, incomplete filling of the groove can be readily detected and a consequent control signal obtained for reducing the temperature of the stock, such reduction leading to an increased widening during rolling and hence to proper filling of the groove. However, a corresponding control signal for increasing the stock temperature when necessary cannot be conveniently obtained since it would necessarily result from over lling of the groove, and such over filling would cause formation of fins on the rolled product unless the roll pressures were very high. The control signal for raising the stock temperature may, therefore, be more conveniently obtained by `detecting the reduction of the roll speed or overloading of the roll driving motors which will `occur if the temperature is too low and the widening of the stock is, therefore, excessive.

Sections are advantageously rolled by the method of the invention in a separately erected and separately operated mill stand. This is advisable on the one hand because the method according to the invention is preferably carried out at relatively low rolling speeds, if possible under 2 m./sec., since with higher rolling speeds and sections which have to be rolled out with a large pass reduction the bite or receiving capacity of the rolls is no longer sufficient. On the other hand this results in uniform distribution of the production in the auxiliary equipment, which therefore need be designed only for a substantially lower output per hour.

Most sections to be produced can be rolled from coilable stock. The stock can therefore be rolled at the highest possible `speed that is to say Iwith full loading of the preceding rolling mill, since coilers permit substantially higher final speeds, namely approximately twice as high as those of cooling beds to which the sections would otherwise have to be discharged. In addition, a number of dierent sections can be produced from one and the same stock, so that modication of the preceding rolling mill is required far less frequently than in the case of direct rolling of sections in small batches.

Owing to the fact that the rolling of sections in accordance with this invention is thus effected separately, the capacity of the preceding rolling mill can be considerably more intensively utilised. For this reason and because of the smaller cost of equipment the saving is greater than the cost incurred by re-heating of the rolling stock for rolling sections.

For many sections the method according to the invention provides very considerable pass reductions of up to 70%. The receiving capacity of the rolls is utilised to the uppermost limit with such pass reductions and accordingly the bite of the rolls is far exceeded. The stock must therefore be pointed or tapered to enable it to be introduced into the rolls, or according to another feature of the invention, which is however known in itself, the rolls are set after the tip of the stock has been introduced into the roll gap which is opened for that purpose, this being a simpler procedure.

Through the pointing or tapering of the stock, or its introduction into the roll gap which is previously opened, a loss of material results. The heating of the stock through, in order to enable the temperature to be accurately adjusted in accordance with the filling of the roll grooves is effected in a second or later heating stage, so that a waste piece also occurs at the end of the stock. Such heating is preferably carried out electrically, through resistance heating of the stock by passage of the current therethrough between two sets of contact rollers bearing on the stock. The economy of the method according to the invention can be increased if according to another feature of the invention, which however is known in itself, and with the particular object of reducing wastage the pieces of stock being rolled one after the other are first welded together so that rolling can be carried out continuously.

Since the receiving capacity of the rolls must be very extensively utilised when rolling sections with a large pass reduction, according to another feature of the invention the stock should be fed to the rolls Without or substantially without tension.

According to another feature of the invention it is also advisable for the stock to be pulled from the rolls under a tension sufficient to maintain the same straight in order to counteract a tendency to curve sideways, which may exist in the case of certain sections. tension may be increased up to a value limited by the cross-section and strength of the material, although experience to date has shown that the application of a tension sufficient to influence the fiow conditions in the roll gap is not necessary.

Some exemplary embodiments of the invention in details of rolling mills suitable for carrying out the method of the invention are illustrated in the accompanying drawings, in which:

FIGURE 1 shows one example -of the construction of a rolling mill,

FIGURES 2 and 3 show details thereof,

FIGURE 4 shows an elevation of another embodiment,

FIGURE 5 shows a corresponding plan View,

FIGURE 6 a detail thereof,

FIGURE 7 shows an elevation of a modification of the embodiment illustrated in FIGURES 4 and 5,

FIGURE 8 a detail thereof in plan view,

FIGURE 9 shows an example of the construction of a rolling mill,

FIGURE 10 an example of the construction of a mill stand drive,

FIGURE l1 a roll groove which always works with incomplete filling, and

FIGURES 12 to 17 show sections of incoming steel and the respective outgoing steel rolled in a single pass.

The core of the rolling mill both in the embodiment illustrated in FIGURE 1 and in that illustrated in FIG- URES 4 and 5 is a mill stand 1 which is preceded by stands 2a and 2b receiving Contact roll sets and followed by an auxiliary stand 3. The stock fed to the mill stand 1 is designated by 4 and the outgoing rolled stock is designated by 5.

The incoming stock 4 is heated to rolling temperature by electric resistance heating. From the transformer 6 the output of which is adjustable the current is fed to and taken from the stock 4 through the Contact roller sets mounted in the stands 2a and 2b. While the stand 2b is mounted fast on a bed plate 7, the stand 2a is mounted on a slide 7a adapted to travel on the bed plate 7 in the longitudinal direction of the stock 4, for which purpose there is provided a threaded spindle 8 mounted in the bed In special cases the plate 7 and rotatable by means of a handwheel 8a, the said spindle engaging in a nut on the slide 7a. The movability of the stand 2a is provided in order to enable the distance between the contact roller sets mounted in the stands 2a and 2b and hence the length of the resistance path in the stock 4 to be adjusted in accordance with the cross-section of the latter, while the fine regulation is effected in the primary circuit of the transformer 6.

The regulation of the heating current (movement of the stand 2a, regulation of output of transformer 6) can be effected by measuring the temperature of the incoming stock 4 or, as in the case of the embodiment illustrated by way of example in FIGURE l, of the outgoing stock 5 by means of a radiation pyrometer 10. The measured temperature of the stock is continuously compared with a reference value and the heating of the stock is controlled to bring the measured temperature into equality with the reference value. The latter is itself determined by the degree of filling of the roll groove as determined, for example, by continuous measurement of the rolled product and comparison of the result of such measuree ment with predetermined dimensional standards. Thus, it will be seen that the degree of filling of the grooves is continuously measured and determines the temperature reference value which in its turn determines the heating and hence the temperature of the stock. The control is so arranged that if the degree of filling of the roll groove decreases, the reference temperature is decreased and hence the stock temperature is decreased to a value at which the increased widening of the stock during rolling will fill the roll groove and similarly, if the degree of fi1ling of the roll groove is excessive the stock temperature is raised.

Preferably the continuous measurements and comparison of temperature and groove filling are carried out automatically by suitable known devices and control circuits of known type, which will not be described in detail. However, manual control by one or more operators is possible. Thus an operator may observe the dimensions of the rolled product and manually adjust the temperature reference value in accordance with a predetermined relation between temperature and rolled dimensions. Also the actual temperature can be controlled by an operator manually controlling the heating current or contact spacing in accordance with an indicated value of the reference temperature. It will be clear that in either automatic or manual operation, the stock temperature is adjusted to a desired value depending on the degree of filling of the roll groove.

The intermediate step of establishing a temperature reference value could be omitted. Thus, the embodiment illustrated in FIGS. 4 and 5 has following the mill stand 1 an apparatus 11 for continuous measurement of the main dimension of the outgoing rolled material, this actual value being compared with an index value and the heat current being regulated in accordance with the resulting deviation in dimensions of the rolled material, the main dimension selected being one which at the same time gives an indication of the degree of filling of the roll grooves, for example the width in the case of a flat section.

The auxiliary stand 3 following the mill stand 1 can serve many diverse purposes. Thus it can for example serve as an extraction driver for the purpose of pulling the outgoing rolled material from the rolls under tension. It can moreover be used for equalising the rolled section, for which purpose it is then disposed, as in the embodiments illustrated, with rolls offset by in relation to the rolls of the mill stand 1. I The auxiliary stand 3 also permits the production of sections having undercut portions, for example of sections having a dovetail-shaped longitudinal groove or a projecting tongue of dove-tail shape. For this purpose a section having av rollable groove and corresponding beads at the groove edges is produced in the mill stand 1. The beads at the groove edges are then rolled down in the auxiliary stand 3 so that the desired dovetail-shaped groove is produced. For the example mentioned, the auxiliary stand 3 would then be disposed differently from the embodiments illustrated, its rolls lying parallel to the rolls of the mill stand 1 or lying in any other desired position.

As has already been mentioned above, it is possible in many cases, that is to say in the case of small sections and certain medium-sized sections, to use coiled material as the initial stock, that is to say to feed the stock from a coil, as is the case in the embodiment illustrated in FIG- URE l. The coil is designated by 12 and is mounted on a freely rotatable drum 13. A straightening machine 14 is provided which draws the stock 4 from the drum 13 and straightens it. The working speed of the straightening machine 14 is adapted to the speed at which the stock 4 is drawn in by the rolls of the rolling mill 1, so that the stock 4 can be fed to the rolling mill 1 without tension or without any appreciable tension.

The requirement that the stock 4 should be fed to the rolls without tension or substantially Without tension is fulfilled in a particularly simple manner in the embodiment illustrated in FIGURES 1 and 2. The drum 13 with its stand and the straightening machine 14 are mounted on a common base or carriage 15. The carriage 15 is provided with wheels 16 supported on rails 17 and can travel freely in the longitudinal direction of the stock 4. The rails 17 slope downwardly very slightly away from the mill stand, i.e. in a direction opposite to the direction of feed of the stock 4 so that the carriage 15 has a very slight tendency to roll on its Wheels 16 along the rails 17 until the foremost wheels 16 engage the blocks 17a at the end of the rails 17. The carriage 15 with the drum 13 and the straightening machine 14 is situated in this position before the rolling operation starts. The point or tapered end of the stock 4 is then introduced into the straightening machine 14 which pulls the stock 4 from the drum 13 until the point or tapered end is disposed in the opened gap between the rolls of the rnill stand 1. The heating current is then switched on and heats the stock 4 situated between the contact roller sets of the stands 2a and 2b to rolling temperature. The upper roll in the stand 1 is then screwed down by means of the screw-down gear 9 until the stock is gripped by the rolls. When the stock 4 heated to rolling temperature runs into the roll gap of the mill `stand 1, the top roll of the mill stand 1 is screwed down further until the groove in the rollers is closed in accordance with the desired section and the actual rolling begins. The straightening machine 14 is driven by a motor 20 through a transmission having a steplessly variable transmission ratio. In the embodiment illustrated the transmission provided is a V-belt drive 21, in which the cone pulley 22a of the driving cone pulley pair 22a, 22b is mounted non-rotatably but displaceably in the axial direction, while the cone 2211 is fixed on a shaft 23 coupled to the motor 2t) which is mounted on a base 24. The axial displacement of the one cone pulley 22a is eected by means of a fork 25 which through a shaft 26 is nonrotatably connected to a lever 27. The lever 27 carries a roller 28 which is urged by a spring 29 against a fixed cam 30 (see in particular FIGURE 2). In the starting position of the carriage 15 together with the drum 13 and the straightening machine 14, in which the foremost wheels 16 of the carriage 15 lie against the blocks 17a at the end of the rails 17, the roller 28 makes contact with the cam 36 at a point where the height of the cam 35 is slight. The cone pulley 22a is thus situated at a correspondingly great distance from the cone pulley 22b and the V-belt 21 makes contact with the cone pulleys 22a and 22h on a correspondingly small diameter and is thus driven with a correspondingly low peripheral speed by the motor running at constant speed. In this position the straightening machine 14 runs at its lowest working speed. Since the stock 4 is in every case drawn in at higher speed by the rolls of the mill stand 1, the straightening machine 14 together with its carriage 15 and hence also the drum 13 is pulled towards the mill stand 1. The roller 28 is thus brought into a region of greater height of the cam 30 and through the lever 27, the shaft 26, and the fork 25 reduces the distance between the cone pulleys 22a and 22h, so that the V-belt 21 lies against the cone pulleys 22a and 22h on a larger diameter, whereby its peripheral speed and hence the working speed of the straightening machine are increased until the latter corresponds to the speed at which the stock 4 is drawn in by the rolls of the mill stand 1. The stock 4 is thereby subjected only to the smaller tension resulting from the carriage 15 together with the straightening machine 14 and the drum 13 tending to move on the inclined rails 17 against the direction of movement of the stock 4. In order to enable this tension force to be kept as small as possible, the rails 17 are mounted on a rocker 18 the inclination of which can be adjusted by adjusting means 19.

The requirement that the stock 4 should run to the rolls without tension or substantially Without tension can of course also be complied with in other ways. Thus the straightening machine drawing the stock 4 from the storage reel, or any other driving device could be mounted stationary and be driven at a regulable speed, while the speed could be regulated in a known manner, for example in accordance with the size of a loop of stock, between the straightening machine or driving device and the first stand 2a of the contact rollers.

If the desired quantity of a section cannot be rolled from a single coil, it is advisable for the purpose of reducing wastage and avoiding loss of time to weld the end of a new coil of stock to the end of a preceding coil of stock, as is generally customary in wire working.

The outgoing rolled material can be coiled if the section permits this. For this purpose coilers of known constructions can be used. A coiler of the type illustrated in FIGURES 1 and 3 can be used with particular advantage. This coiler consists of a drum 31 of which one part 31a is cylindrical and the other part 31h slightly conical. The drum 31 is mounted rotatably on a stationary journal 32 and joined to an internally toothed rim 33. A pinion 34 meshing with the teeth of the internally toothed rim drives the drum 31 with the aid of a motor 35 through a transmission 36 which serves at the same time as a support for the drum 31. The motor 35 is so regulated that the stock 5 is always pulled from the rolls of the mill stand 1 with a tension which straightens the stock 5. The auxiliary stand 3 can therefore be dispensed with, unless it is required for equalising or additional rolling. The journal 32 on which the drum 31 is mounted is provided with a bearing point 37 for a disc 38 the axis of which lies at a slight angle to the main axis of the journal 32. As the drurn 31 rotates the disc 38 therefore wobbles in the drum 31. The disc 38 is provided with fingers 38a which extend through slits 31a` in the portion 31a of the drum 31. These fingers 38a continuously push off the stock 5 running on to the portion 31a of the drum 31 until it reaches the portion 31h from where it can then be taken off in coils of desired size. The stroke performed by the fingers 38a in their rotation is determined by the inclination of the axis of the bearing point 37 in relation to the main axis of the journal 32 and the stroke should be somewhat larger than the width of the widest section to be coiled.

If it is not possible, or if for reasons of storage it is not convenient to feed stock from a coil, that is to say with coiled stock, the stock 4 can also be supplied in billet form as in the case of the embodiment illustrated in FIG- URES 4 and 5. The individual billets are taken from a suitable storage means 40, for which purpose cross-pushers 41 and a forward pusher 42 are provided.

When billets are used it is particularly to lnerecommended that the successive billets being rolled 1should be welded together. For this purpose there is provided-in a known manner a movably mounted butt welding machine 43 which in each case welds a new billet to the end of the billet 4 entering the mill stand 1 as soon as a length of the billet has run into the mill stand 1. The welding machine 43 can have a separate propulsion drive or can be carried in one direction by the billet to be rolled. If necessary a device for removing weld beads (milling cutter, or the like) can also be disposed between the welding machine 43 and the stand 2a, as well as a driving device or straightening machine.

For sections which cannot be coiled after rolling, a delivery table 45 is provided 'following the mill stand 1 in the embodiment illustrated in FIGURES 4 and 5. In this case the auxiliary stand 3 is used as extraction driver in order to draw the stock from ythe rolls of the mill stand 1 with a tension which straightens it. A stop switch 46 is provided at the end of the delivery table 45 and when operated by engagement with the stock 5 lights up a signal lamp 47. A cutting device 48, which is adapted to travel on a rail S0 carried by supports 49, is at the same time operated by hand or by the stop switch 46. During the cutting operation the cutting device 4S travels with the stock 5. On completion of the cut the 4cutting device 48 returns to the starting position, for which purpose the rail S@ is disposed at a suitable angle. A trough 52 is pivotally suspended on supports 51 above the delivery table 45. As soon as the parting cut has been completed .and a section of desired length has been cut from the outgoing rolled material 5, it is delivered on to a chute 53 from the delivery table 45 by pivotal movement of the trough 52. By way of the chute 53 the section passes into a receiving trough 54 which allows it to slide on to a stacking site 55 (see in particular FIGURE 6).

Instead of the delivery table 45 a cooling bed or an extractor truck such as is customary in drawing mills can also be used. An extractor truck 56 can be used, as illustrated in FIGURES 7 and 8. Two .extractor trucks could also be.used, Which in a known manner continuously draw out the rolled material in alternating small strokes, the cutting device 4S then being disposed after the extractor trucks. When extractor trucks are used, the auxiliary stand 3 can once again be dispensed with, unless it is needed for equalising or supplementary rol-ling.

In the embodiments described the heating of the rolled material to rolling temperature has been eiected exclusively by electric resistance heating. This heating has the advantage of easy regulability. This does -not mean that the invention is restricted `to this type of heating. Gas or oil-red continuous furnaces can also be advantageously utilised according to the invention, preference being in fact given to these furnaces if the stock to be heated has a relatively large cross-section. The combination of a furnace for pre-heating with an electric resistance heating device for the further `heating ,of the stock to a determined and regulated temperature can also be particularly advantageous. Pre-heating is preferably elected to a temperature lying slightly beneath the scaling limit, that is to say about 600 to 650 C. The pre-heating can be effected in any desired furnace, for example in the caseV of the embodiment illustrated in FIGURES 4 and 5 the billet storage means 40 may be replaced by a furnace 40a. It is however also possible to use a continuous furnace which could then be disposed in advance of the welding device 43 and in advance of the stand 2a.

One example of the construction of a set of rolls is illustrated in FIGURE 9. The set is provided for rolling a U or channel section. The rolls in this embodiment consist of a core and roll rings mounted thereon and held by a nut. Thus the top roll consists of the core 61, the roll rings 62, 63, and 64 and the nut 65. ,The lower roll consists of the core 66, the roll rings 67, 68, and 69 and the nut 70. In the case of all rolls which in Iaccordance with the groove to be rolled have roll surfaces which are radially at or substantially radially ilat, against which the stock slides with considerable transverse force and which are thus subject to wear, it is advisable for the roll to be composed, as in the embodiment illustrated, of a core on which roll rings are mounted. Thus the proiile of the set of rolls can be repeatedly modied in the embodiment illustrated by repacing the roll ring 63 of the top roll and re-machining the roll rings.

In the ease of sections which do not require radially flat or substantially radially at roll surfaces, for example angles, the roll can be made in one piece since rolls of this type can be ire-machined without difficulty.

In order to produce a cleanly shaped section free from fins, an absolutely closed roll groove is necessary in the case of most sections. The groove joint between the top roll and bottom roll should be held closed under pressure when rolling such sections, Afor which purpose the rolls are provided with body surfaces 71 which make `contact with one another un'der pressure and which lie in the groove joint. The distance between the rolls and the pass parting are thus at the same time accurately determined.

In order that the flow of material may adjust itself freely, .it is advisable for only one roll to be positively driven. The second roll may either be entirely without drive, as is the `case with the set of rolls illustrated in FIGURE 9, or it can be provided with an auxiliary drive. The auxiliary drive provided can, for example, be of the type having a drive which is automatically switched ol after the initial entry of the stock. Another possible construction orf the auxiliary drive is shown in lthe embodiment illustrated by way of example in FIGURE l0. Here the top roll 72 is driven by an articulated spindle 73 and gearing 74 by a fixed speed main drive motor 75 which determines the rolling speed. The lower roll '76, on the other hand, is driven through an articulated spindle .'77 and gearing 78 ,by an auxiliary drive motor 79 the speed of which is adjustable and at the same time provides a limited power output.

In the case off non-symmetrical sections there is a danger that the incoming stock will run sideways in the direction of the largest groove opening.

This incorrect running may in certain circumstances have the eiTect that the roll groove will be lilled on one side only despite all precautions. In order to prevent the incoming material from running sideways in this way, according to the invention a transversely displaceable inlet guide is provided for the stock in front of the rolls, whereby a determined distribution of material in the roll groove can be obtained. Rigid roll guides are particularly suitable :for this purpose.

FIGURE 11 shows on a greatly enlarged scale a roll groove which is successfully used for producing sections for umbrella rods. The roll groove formed by the top roll and lbottom roll 86 is lled during rolling only to the width shown in black. If the widening of the stock in the groove becomes greater or smaller, the excess or deliciency, as compared with the required width of the section, is measured and the temperature of the incoming stock is varied in accordance with the result of the measurement until the required width oct the section is once more attained.

FIGURES 12 to 17 show side by side cross-sections of incoming stock (round or square sections) and opposite each of them the sections which have been rolled from them in a single pass.

The methodV according to the invention is primarily applicable to carbon steels but may also be used with alloyed steels, for example manganese, chromium, nickel, and molybdenum stools. However, it can also lbe employed successfully in the rolling of non-ferrous metals, such as lforexample aluminium.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that fwhich is shown in the drawings and described in the specification, but only as lindicated in the appended claims.

What I claim is:

1. A method of rolling an elongated metal body to form a profiled icross section, said method comprising the steps of heating said body to a desired rolling temperature by passing a predetermined electric current through a predetermined length thereof, passing the heated body in a single pass through `a roll groove defined between rolls of a rolling stand to roll said body into said profiled form, and continuously regulating the temperature to which said body is heated in accordance with the degree of filling of said roll groove by said body, said temperature being increased when said roll groove is over filled and being decreased when said roll groove is insufiiciently filled.

2. A method according to claim 1 wherein at least one dimension of said body after rolling is continuously measured 4and compared with a predetermined reference dimension and said continuous regulation of said temperature is performed in accordance with the difference between said measured dimension and said reference dimension to reduce said difference.

3. A method according to claim 1 comprising the steps of continuously measuring at least one dimension of said body after rolling, comparing said dimension with said predetermined reference dimension, determining by a predetermined relation from the difference between said measured dimension and said reference dimension a reference temperature adapted to ensure correct filling of said roll groove, continuously measuring the temperature of said heated body and comparing said measured temperature with said reference temperature, and regulating the temperature to which said body is heated to reduce the difference between said measured temperature and said reference temperature.

4. A method of rolling an elongated metal body to form a profiled lcross section, said method comprising the steps of heating said body to a desired rolling temperature by passing a predetermined electric current \through a predetermined length thereof, passing the heated body in a single pass through a roll groove defined between rolls of a rolling stand to roll said body into said profiled form, continuously detecting the degree of filling of said roll groove by said body, and continuously regulating the temperature to which said body is heated in accordance with the degree of filling of said roll groove by said body, said temperature being increased when said roll groove is over filled and being decreased when said roll groove is insufficiently filled.

5. A method of rolling an elongated metal body in a single pass between two parallel cooperating rolls of a mill stand to form a profiled cross section, said method comprising the steps 1of separating Said rolls, inserting the leading end of said body between said rolls, heating said body to a desired rolling temperature by passing a predetermined electric current through a predetermined length thereof, closing said rolls, passing the heated body in a single pass through a roll groove defined between said rolls to roll said body into said profiled form, continuously detecting the degree of filling of said roll groove by said body, and lcontinuously regulating the temperature to which said body is heated in accordance with the degree of filling of said roll groove by sa-id body, said temperature being increased when s-aid roll groove is over filled and being decreased when said roll groove is insufficiently filled.

6. A method of rolling an elongated metal body to form a profiled cross section, said method comprising the steps of heating said body to a desired rolling temperature by passing a predetermined electric current through a predetermined length thereof, passing the heated body in a single pass through a roll groove defined between rolls of a rolling stand to roll said body into said profiled form, continuously detecting the degree of filling of said roll groove by said body, and continuously regulating the temperature to which said body is heated in accordance with the degree of filling of said roll groove by said body, said temperature being increased when said roll groove is over filled and being decreased when said roll groove is insufficiently filled, and said body being fed to said rolls at least substantially without tension.

7. A method of rolling an elongated metal body to form a profiled cross section, said method comprising the steps of heating said body to a desired rolling temperature by passing a predetermined electric current through a predetermined length thereof, passing the heated body in a single pass through a roll groove defined between rolls of a rolling stand to roll said body into said profiled form, continuously detecting the degree of filling of said roll groove by said body, and continuously regulating the temperature to which said body is heated in accordance with the degree of filling of said roll groove by said body, said temperature being increased when said roll groove is over filled and being decreased when said roll groove is insufiiciently filled, and said body being withdrawn from said rolls under a tension sufficient to straighten said body.

8. Apparatus for rolling an elongated metal body in a single rolling pass to form a desired profiled cross section, said apparatus comprising a rolling stand having two rolls which between them define a roll groove for rolling said desired cross section on said body, two spaced electrical contact means engaging said body for passing a predetermined electric heating current through a predetermined length of said body before rolling to heat the body, the distance between said Contact means and the magnitude of said current being adjustable, whereby said body can be heated to a desired rolling temperature, means for measuring at least one dimension of said body after rolling, means for determining the difference between said dimension and a predetermined dimension, and means for Varying the distance between said contact means for adjusting the temperatures to which said body is heated by said heating current so as to reduce said difference.

9. Apparatus for rolling an elongated metal body in a single rolling pass to form a desired profiled cross section, said apparatus comprising a rolling stand having two rolls which between them define a roll groove for rolling said desired cross section on said body, two spaced electrical Contact means engaging said body f-or passing a predetermined electric heating current through a predetermined length of said body before rolling to heat said body, the distance between said contact means and the magnitude of said current being adjustable whereby said body can be heated to a desired rolling temperature, means for measuring at least one dimension of said body after rolling, means for determining the difference between said dimension and a predetermined dimension, means for determining from said difference a reference temperature adapted to ensure correct filling of said roll groove, means for measuring the temperature of said body after heating, means for determining the difference between said temperature and said reference temperature, and means for varying the distance between said contact means for adjusting the temperature to which said body is heated by said heating currents so as to reduce said last mentioned difference.

10. Apparatus for rolling an elongated metal body in a single rolling pass to form a desired profiled cross section, said apparatus comprising a rolling stand having two adjustable rolls which between them define a roll groove for rolling said desired cross section on said body, two spaced electrical contact means engaging said body for passing a predetermined electric heating current through a predetermined length of said body before rolling, the distance between said contact means and the magnitude of said current being adjustable whereby said body can be heated to a desired rolling temperature, a freely rotatable drum Vfor supporting a coiled supply of stock, a straightening machine for withdrawing said stock from said drum and feeding the same to said roll stand, a common `support carriage 'for said drum and said machine, said support carriage being movable toward and away from said roll stand, .and driving means for said machine comprising a steplessly variable transmission and means for varying the transmission ratio of said transmission in accordance'with the position of said support carriage, whereby the speed of said machine is increased as said carriage approaches said roll stand.

11. Apparatus according to claim comprising tiltable means on which said carriage rests and moves, the inclination of said tiltable means relative to the direction of motion of said carriage being adjustable.

12. Apparatus for rolling an elongated metal body in a single rolling pass t-o form a desired proled cross section, said apparatus comprising a rolling stand having two adjustable rolls which between them define a roll groove for rolling said desired cross section on said body, two spaced electrical .Contact means engaging said body for passing a predetermined electric heating current through a predetermined length of said body before rolling, the distance between said Contact means and the magnitude of said current being adjustable whereby said body can be heated to a desired rolling temperature, and a coiler for coiling said body after rolling, said coiler comprising a fixed shaft, a ceiling drum having slots therein and journaled on said shaft, said shaft having an oblique portion, a disk journaled on said oblique portion, and fingers on said disk projecting through the slots in said drum in the region where said body first engages said drum, whereby upon rotation of said drum said disk will wobble on said shaft and said ngers will oscillate to slide said coiled body along said drum.

13. Apparatus for rolling an elongated metal body in a single rolling pass t0 form a desired protiled cross section, said apparatus comprising a rolling stand having two rolls which between them define a roll groove for rolling said desired cross section on said body, two spaced electrical contact means engaging said body for passing a predetermined electric heating current through a predetermined length of said body before rolling to heat the body, the distance between said contact means and the magnitude of said current being adjustable, whereby said body can be heated to a desired rolling temperature, means for measuring at least one dimension of said body after rolling, means for determining the difference between said dimension and a predetermined dimension, and means for varying the magnitudeof said heating current for adjusting the temperature to which said body is heated by said heating current so as to reduce said difference.

14. Apparatus for rolling an elongated metal body in a single rolling pass to form a desired profiled cross section, said apparatus comprising a rolling stand having two rolls which between them define a roll groove for rolling said desired cross section on said body, two spaced electrical 1Contact means engaging said body for passing a predetermined electric heating current through a predetermined length of said body before rolling to heat said body, the distance between said contact means and the magnitude of said current being adjustable whereby said body can be heated to a desired rolling temperature, means for measuring at least one dimension of said body after rolling, means for determining the difference between said dimension and a predetermined dimension, mea-ns -for determining from said diiierence a reference temperature adapted to insure correct filling of said roll groove, means for measuring the temperature of said body after heating, means for determining the difference between said temperature .and said reference temperature, and means for varying the magnitude of said heating current for adjusting the temperature to which said body is heated by said heating current so as to reduce said last mentioned difference.

References` Cited by the Examiner UNITED STATES PATENTS 1,023,316 4/1912 Hurwitz 205 1,336,177 4/1920 Withers 80-54 1,590,854 6/1926 Rothera et al. 80-54 1,655,886 1/1928 Baehr 80-58 2,138,982 12/1938 Raydt 80-32 2,296,683 9/1942 Morgan et al. 80-43.3 2,313,702 3/1943 Allen 80-2 2,393,702 1/1946 Naegeli 153-95 2,863,557 12/1958 Munker 207-2 FOREIGN PATENTS 862,922 12/1940 France.

896,332 ll/l'3 Germany.

519,409 3/ 1940 Great Britain.

CHARLES w. LANHAM, Primary Examiner. WILLIAM J. srEPHENsoN, Examiner,

Claims (2)

1. A METHOD OF ROLLING AN ELONGATED METAL BODY TO FORM A PROFILED CROSS SECTION, SAID METHOD COMPRISING THE STEPS OF HEATING SAID BODY TO A DESIRED ROLLING TEMPERATURE BY PASSING A PREDETERMINED ELECTRIC CURRENT THROUGH A PREDETERMINED LENGTH THEREOF, PASSING THE HEATED BODY IN A SINGLE PASS THROUGH A ROLL GROOVE DEFINED BETWEEN ROLLS OF A ROLLING STAND TO ROLL SAID BODY INTO SAID PROFILED FORM, AND CONTINUOUSLY REGULATING THE TEMPERATURE TO WHICH SAID BODY IS HEATED IN ACCORDANCE WITH THE DEGREE OF FILLING OF SAID ROLL GROOVE BY SAID BODY, SAID TEMPERATURE BEING INCREASED WHEN SAID ROLL GROOVE IS OVER FILLED AND BEING DECREASED WHEN SAID ROLL GROOVE IS INSUFFICIENTLY FILLED.

13. APPARATUS FOR ROLLING AN ELONGATED METAL BODY IN A SINGLE ROLLING PASS TO FORM A DESIRED PROFILED CROSS SECTION, SAID APPARATUS COMPRISING A ROLLING STAND HAVING TWO ROLLS WHICH BETWEEN THEM DEFINE A ROLL GROOVE FOR ROLLING SAID DESIRED CROSS SECTION ON SAID BODY, TWO SPACED ELECTRICAL CONTACT MEANS ENGAGING SAID BODY FOR PASSING A PREDETERMINED ELECTRIC HEATING CURRENT THROUGH A PREDETERMINED LENGTH OF SAID BODY BEFORE ROLLING TO HEAT THE BODY, THE DISTANCE BETWEEN SAID CONTACT MEANS AND THE MAGNITUDE OF SAID CURRENT BEING ADJUSTABLE, WHEREBY SAID BODY CAN BE HEATED TO A DESIRED ROLLING TEMPERATURE, MEANS FOR MEASURING AT LEAST ONE DIMENSION OF SAID BODY AFTER ROLLING, MEANS FOR DETERMINING THE DIFFERENCE BETWEEN SAID DIMENSION AND A PREDETERMINED DIMENSION, AND MEANS FOR VARYING THE MAGNITUDE OF SAID HEATING CURRENT FOR ADJUSTING THE TEMPERATURE TO WHICH SAID BODY IS HEATED BY SAID HEATING CURRENT SO AS TO REDUCE SAID DIFFERENCE.

Images