US3382696A - Apparatus for working metals and other materials - Google Patents

Description

May 14, 1968 G. MARTELLE 3,382,696

APPARATUS FOR WORKING METALS AND OTHER MATERIALS Filed Sept. '7, 1965 rryc United States Patent O 3,382,696 APPARATUS FOR WORKING METALS AND OTHER MATERHALS Ghislain Martelee, 71 Quai de Rome, Liege, Belgium Filed Sept. 7, 1965, Ser. No. 485,514 Claims priority, application Luxembourg, Sept. 8, 1964,

s claims. (ci. 'l2- tarn ABSTRACT F THE DlSSL-GSURE This invention relates to improvements in and relating to working metals and other materials. This expression is to be understood to mean all such operations as rolling, hammering, forging, drawing, spinning, wiredrawing, and the like and in general any operation which causes a `deep or superficial change in shape in the material Ibeing worked.

It is applicable to all materials, whether metallic or not, which are capable of being worked by any of the above operations. lt is however more specially adapted to .the production of fiat metallic products.

The invention referred to above has as its object the modification of the cross-section and possibly the form of a basic material, the imparting to the material a given surface, for example a smooth surface, and also certain mechanical properties. Some special aspects proper to certain of these processes are briefly recalled below.

In the commonest rolling process, these modifications are obtained by passing a basic material (in the form of slabs, blooms, ingots, in the case of steel) through a nip between motor driven rolls, the axes of which are fixed during any particular pass.

At each pass the resultant of a part of the compressive forces exerted by the rolls on the material being rolled, and on the other hand tension from the tractive force exerted in the direction of movement of the said material, produce in it a permanent deformation. This permanent deformation may only exist at the surface, as usually happens in skin-pass operations or any other operations of a superficial or surface nature.

It is known that to assist in rendering the rolling operation technically efficient and commercially' viable, it is advantageous to reduce the diameter of the rolls and support them on others of larger diameter. It is thus possible to reduce the deformations due to the flexing of the working rolls and to reduce the tolerances of the rolled products.

It has also been proposed to design a planetary type mill, that is to say a mill comprising a set of small working rolls distributed round the circumference of two large motor driven cylinders, which because of their rotation, successively bring all the small working rolls into contact with the material to be rolled in accordance with a process resembling that known as down-stream milling. This mill is however 4noisy in operation and is subjected to repeated shocks.

ln the conventional process of drawing or wiredrawing, the material to be drawn or wiredrawn is forcibly pulled through a die, the walls of which exert great pressures on the material and produce the desired cross-section. In

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this type of operation considerable friction and heat are produced, jammings are common and the die wears rapidly in spite of adequate lubrication.

In the case of the spinning process, the drawbacks remain of the same kind, although reduced by the use of certain special lubricants such as viscous glass. For these two processes it should be pointed out that the energy is solely supplied to the material either by traction or by compression, which however imposes a restriction on the force transmitted to the said material as otherwise there would be an alteration in its mechanical properties.

This invention relates to apparatus which avoids or substantially reduces the draw-backs mentioned above.

The working of material according to the present invention is essentially characterized in that the basic material is reduced 'between plural rolls or dies, of suitable profile, each pair being made to follow convergent and/ or parallel paths in such a way that they block the material progressively and in such a way that the profile along the envelope Surface, produced by the gcneratrices of Contact between rolls or dies and the material during the working along the line of movement of the said rolls or dies, is oblique to the axis of the material during the treatment, the said Obliquity being either linear or curved with a variable radius, the said material being further possibly subjected t0 a tractive force or a thrust independent of the rolls or dies.

The above mode of operation offers the important advantage of substantially reducing the shocks transmitted to the frame and ensuring a finished product manufactured to the closest tolerances.

According to another advantageous feature, the rolls have the same diameter or have an increasing diameter according to Whether or not they are placed within convergent or parallel guides or slides. lt should be noted that it ispossible to use the process in the invention imparting to the rolls a movement in the reverse direction from that of the extraction of the -treated material.

in accordance with yet another advantageous feature the rolls are provided with pedestal bearings in which they rotate idly so that each roll can rotate at its own speed, which may be different from that of the other rolls.

According to a further feature of the method in accordance with the invention, the rolling operation is completed by means of several pairs of rolls, the spacing between the two rolls of every pair being the sa-me, which allows products to be obtained with especially close tolerances.

in the case where convergent guides are used it has been found advantageous to make the guides precede and follow inlet and discharge connecting elements making possible on the one hand the progressive gripping of the material by the inlet rolls and on the other hand the progressive release of this material by the discharge roll, which substantially avoids shock and corresponding noise, and on the other hand obtains a gradual placing under load and release from load of the frame.

It has likewise been found advantageous lto subject temporarlly all or part of the tables of the rolls to a fixed supporting action, which reduces the deformation of the rolls and allows the product to be impelled better due to the tangential force developed between the support and the tables of the rolls.

In accordance with other advantageous embodiment, the rolls are used continuously and preferably in a closed circuit, that is lto say each roll after having carried out its rolling operation, is reintroduced at the input side of the device as if it were a new roll. The advantage of such a mode of embodiment is selfcvident.

A preferred embodiment of the device forming the subject matter of the present invention is characterized in that comprises: a frame having two flanges facing one another and each provided with two slides or roller bearn ings, which may be convergent and/ or parallel, the slides of one frange being similar to those of the other similarly arranged facing these latter.

Two sets of rolls provided at each end with a journal, each roll resting on the two anges by means of these journals and correspondin g bearing blocks, accommodated in the said slides or bearings, the axis of the rolls being perpendicular to the plane of the flanges.

A device causing the rolls t0 move all together at the same time in the slides or bearings.

A device maintaining the distance between the rolls of a given set.

vlt must be expressly understood that in the above device the rolls may be replaced by any kind of dies or any other treatment member.

According to a feature, the feed device for the rolls is of the endless chain type.

According to another feat-ure, the convergent bearings or slides are provided at each of their ends with an extension parallel to the plane bisecting their angle of convergence, and preferably their connection gradually.

According to yet another feature these parallel extensions are movable and adjustable.

it has also been found advantageous in some cases to provide the device of the invention with a member pulling or thrusting the product treated and/ or the basic material.

Specific embodiments of the invention will now be described by way of example with reference to the accompanying drawing, in which:

FIGURE l shows a longitudinal section through a rolling mill for carrying out the method in accordance with the invention,

FlGURE 2 is a cross-section taken on the line li-II oi FIGURE 1.

Referring to the drawing, a rolling mill comprises a cage formed by a pair of rivid uprights 1 (only one of which is shown) spaced apart by cross-members 2. Channel-like guides 3 formed in the inner face of each upright 1 provide paths 5 along which are arranged to travel bearing blocks i formed as roller bearings, the outer races of which roll in the guides 3. Each bearing block fi co-operates with a bearing block associated with the lupright opposite and following a similar path to idly support a roll o. Adjacent bearing blocks are spaced and connected by links 7 to form two endless chains of rolls which, because of the orientation of the paths 5, are caused to converge towards the discharge end of the mill.

Each endless chain is provided with two sets of sprockets 8 which serve to drive it and maintain its rolls in phase with those in the other chain. Motion is transmitted from the sprockets to the chains by teeth 9 which engage the journals lil of the rolls 6.

A strip 11 of the material to be rolled enters the mill where the chains of rolls have the greatest spacing and leaves at the other end where the chains of rolls have the smallest spacing. It is then driven by a conveying means not shown in the drawing.

The mill further comprises at the inlet and outlet, moveable guide components 12 which act as a progressive connecting element to the fixed convergent guides.

guide components 12 may 4move parallel to the convergent guides and have a surface parallel to the materials axis which makes it possible for them to admit materials of different thicknesses at the inlet side and to modify the thickness of the rolled product.

The guides 12 consist of a series of fiat members 13 slidable against the flat surface of the uprights l.

The members 13 have flanges to prevent the components 12 escaping if there is no material being rolled.

T he components can slide, supported on surfaces which are parallel to the guides of the uprights.

The other faces i5 of these components are parallel to one another.

By moving the components 12 at the inlet along the CII surface 14 away from the mill, material having greater thicknesses may be admitted, while the final thickness of the rolled material may be increased by moving the components at the outlet towards the mill, or reduced by moving them away from it.

The control devices for the slides 12 are not shown in the figure. They may be for-med for example by hydraulic jacks which require a comparatively large travel if the gradient of the guides is small and vice versa.

The rolling forces both at the input side and at the discharge side decrease towards the end of the mill, which makes it possible to provide a form with a section which decreases (with equal strength) towards the ends.

The mill described above is operated as follows:

The inlet slide components 12 are moved by a hydraulic jack to a position wherein the distance between the two pairs of rolls occupying the leading positions is greater than the thickness of the material to be rolled, which allows the material to be easily introduced.

The discharge slide components 12 are moved by means of a hydraulic jack to obtain a distance between the three rolls occupying the trailing position which is equal to the desired thickness ofthe product.

The material to be treated is then inserted in the device and the sprockets are set in motion at low speed. At this moment the ixed support may be brought into place so as to produce the entrainment of lthe material because of the forces described above.

The material then travels progressively between the different pairs of rolls; the rate of flow of the material being constant and the reduction progressive, the flow speed gradually increases as does also the speed of rotation of the rolls which easily adapt themselves to this continuous increase in speed as they are mounted idly in their bearing blocks.

The inlet slide components 12 are then moved to obtain a distance between the instantaneous two pairs of leading rolls equal to the thickness of the product at the inlet. This avoids an abrupt attack on the material and the rolling commences gradually, noiselessly and without exaggerated shock.

The strip 11 at the outlet is then fixed to the conveying means and the sprockets are speeded-up until the optimum speed is reached.

Automatic control of the discharge thickness can be obtained by acting on the hydraulic jack controlling the movement of the slides 12.

Apart from those already mentioned the method and apparatus of the invention offer the following further advantages-due to the wedging effect of the convergent guides, the rolling forces are to a large extent taken up by the frame, the screws or control chains or the support screws only taking a very small part of these forces, by contrast with present conventional practice where the screws actuated during the passage of the product take up all the rolling operation forces.

This type of embodiment makes it possible to obtain products with very close tolerances of thickness; in fact, in the caseof a rolling operation, the rolls acting in the parallel guides only roll the excess thicknesses arising from the yielding at the proceeding rolls.

The last pass is carried out practically without reduction, consequently practically without any force between the rolls and iinally practically without yielding, that is to say at a thickness which is strictly equal to that desired.

This embodiment likewise makes possible (as has already been pointed out above) a gradual attack of the material at the input side thus avoiding noise and repeated shocks on the rolls and on the mechanical equipment for control purposes and for taking up the forces exerted.

lt is also important to note that the use of idler rolls nakes it possible to avoid making windows in the upright cage, which windows in conventional rolling mills are necessary for the replacement of the rolls, for passing through extension shafts, etc. The transmission of forces can thus be effected under favourable conditions.

It is advantageously possible to control the movement of the support rolls of conventional rolling mills by means of hydraulic jacks actuating wedges with very sharply inclined surfaces.

The preceding description has described the case where the approach movement of the rolls or dies is produced by means of guides or slides. The scope of the invention of course covers any other manner of designing and producing a similar movement of the said rolls or dies such as for instance any articulated system with extending arms, etc.

What I claim is:

1. A rolling mill comprising in combination a pair of opposed endless roller chains having rolls journalled thereon, journals on the outer sides of the chains, a pair of spaced uprights having confronting surfaces, cro-ssmembers securing together said uprights to form a cage, said confronting surfaces of said uprights having channellike paths in which said journals are disposed, drive means for circulating said endless chains, guides for said chains located at the inlet and at the outlet of the path between the chains for the material to be rolled, and means mounting said guides for sliding movement on and relative to said uprights thereby to vary the distance between the rolls at said inlet and at said outlet.

2. A rolling mill as claimed in claim 1, said paths converging from said inlet towards said outlet.

3. A rolling mill as claimed in claim 1, said guides having guide surfaces for the chains disposed parallel to the longitudinal axis of the product to be rolled.

4. A r-olling mill as claimed in claim 1, said drive means comprising toothed sprockets whose teeth engage between said journals.

5. A rolling mill as claimed in claim 1, and means mounting said guides for sliding movement on and relative to said uprights in a direction at an angle to the longitudinal axis of the material to be rolled, said guides having guide surfaces for the chains parallel to the longitudinal axis of the material to be rolled so that sliding movement of said guides along said uprights moves said guide surfaces toward or away from said axis.

References Cited UNITED STATES PATENTS 2,978,933 4/l96l Sendzimir 72-190 2,811,060 10/ 1957 Sendzimir 72--190 2,792,730 5/1957 Cozzo 72-241 2,684,000 7/1954 Holtz 72-190 FOREIGN PATENTS 908,849 4/ 1954 Germany.

CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner.

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