US2932852A - Apparatus and process for rolling metal - Google Patents

Description

April 19, 1960 w. MELVILLE ETAL APPARATUS AND PROCESS FOR ROLLING METAL 3 Sheets-Sheet 1 Filed May 2, 1958 FIG. 5a

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APPARATUS AND PROCESS FOR ROLLING METAL Filed May 2, 1958 3 Sheets-Sheet 2 MLL l/7M ME 1, 101,4 5 hflA EL 5/? x L Q M,MWMLW April 19, 1960 w. MELVILLE E I- 2,932,852

APPARATUS AND PROCESS FOR ROLLING METAL Filed May 2, 1958 3 Sheets-Sheet 3 43 W W wiw FIG. 7.

FIG. 9.

W/LL/AW W51. I//AL AAVM-L SAXA United States Patent APPARATUS AND PROCESS FOR ROLLlNG METAL William Melville, Birmingham, and Karel Saxl, Sutton Coldfield, England, assignors to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain Application May 2, 1958, Serial No. 732,741 Claims priority, application Great Britain May 3, 1957 Claims. (Cl. 18-9) This invention is concerned with apparatus and a process for rolling metal.

It is well-known to manufacture metal in strip form from metal powder by passing the powder between two rolls which compress it. In such a process the width of the powder which is usually fed from a hopper to the nip of the rolls is equal to that of the strip to be produced. It is, however, difficult to produce a strip of the required width since there is a tendency for the powder, as it is fed from the hopper to the nip of the rolls, to leak and spread over the surface of the rolls beyond the required width, thus providing an oversize strip having uneven edges.

According to this invention there is provided a process for producing metal strip by compressing the metal in powder form between two rolls, in which spread of the powder in the nip of the rolls beyond a predetermined width is substantially prevented by two resilient sealing means spaced apart one from the other by that width, one sealing means filling, at least in the region of the nip, a pair of opposed grooves in the rolls, and the other sealing means substantially filling, at least in the region of the nip, a second pair of opposed grooves in the rolls. Also according to the invention, a rolling mill suitable for carrying out the process set forth in the preceding paragraph comprises two rolls, means for feeding the powder to the nip of the rolls, a pair of opposed grooves in the two rolls, a second pair of opposed grooves in the two rolls, and two resilient sealing means, one sealing means substantially filling, at least in the region of the nip, one pair of opposed grooves and the other sealing means substantially filling at least in the region of the nip, the second pair of opposed grooves.

In a first embodiment of the invention, each resilient sealing means is an endless rubber belt passing over two pulleys, one some distance above the nip of the rolls, when the powder is fed from a hopper vertically above the rolls, and the other some distance below the rolls, the belt passing downwardly between the rolls and filling the two opposed grooves towards a side of the rolls, at the nip. In this instance, the belts may form, at least in part, the side walls of the hopper near to the nip of the rolls.

In a second embodiment of the invention, the axes of the pulleys are approximately at right angles to the axis of the rolls and the belt, after passing through the groove in the rolls and over a pulley returns to the other pulley by passing outside the roll housing and between the roll wobblers or coupling boxes. The belts may form an extension of the side walls of the hopper near the nip of the rolls.

The resilient sealing means may conveniently be wholly of rubber or may be a thin, flat belt of relatively hard material, such as steel or nylon, backed by a highly resilient material such as rubber. A rubber belt having a flexible steel band attached to the outer circumference may be used. Preferably, the steel is bonded to the rub 2,932,852 Patented Apr. 19, 1960 her since rivets or similar fastenings may restrict compression of the rubber in passing through the grooves.

In operation the steel face of the belt is presented to the powder passing between the rolls and the purpose of providing a steel face is,.firstly, to prevent wear on the rubber by abrasion by the powder particles and, secondly, to prevent particles being forced into the rubber at the nip where considerable pressures are exerted on the belt by the powder. The use of steel reinforcement is not essential since there are qualities of rubber commercially available which have good abrasion resistance.

The belt should be of such dimensions that the rubber fills and is compressed by the groove at the nip of the rolls. This ensures that the belt is held securely against the side of the groove and thus prevents the formation of a fin on the edge of the strip due to the powder being forced between the belt and the side of the groove or the accumulation of powder in the groove.

In a third embodiment, each resilent sealing means is a rubber band, inflatable or solid, fitted into one of the grooves and projecting from the roll by such an amount that it fills the opposed groove of the other roll at the nip during the rolling operation.

Further objects and advantages of the invention will be in part obvious and in part pointed out hereinafter.

The novel features of the invention may be best made clear from the following description and accompanying drawings in which:

Figure l is a front elevational view of parts of a rolling mill constituting one embodiment of the invention, the roll housings being omitted;

Figure 2 is a plan view of the parts shown in Figure 1;

Figure 3 is a sectional view taken along the line II-I--III of Figure 1;

Figure 4 is a front elevational view, partly in crosssection, of parts of a rolling mill constituting another embodiment of the invention, and wherein the rolls are arrnaged with their axes in the same horizontal plane;

Figure 5 is a cross-sectional view of a belt used in the embodiment of Figure 4;

Figure 5a is a cross-sectional view of another embodiment of an exemplary belt construction that may be used in the embodiment of Figure 4;

Figure 6 is a fragmentary sectional view of the grooves at the nip of the rolls in the embodiment of Figure 4;

Figure 7 is a front elevational view of rolls of a rolling mill constituting still another embodiment of the invention, and wherein the axes of the rolls are in a horizontal plane;

Figure 8 is a plan view of the rolls shown in Figure 7; and

Figure 9 is a side elevation of the rolls shown in Figures 7 and 8.

Referring to the embodiment of the invention shown in Figures 1-3 of the drawings, the two mills 1, 3 of a rolling mill, arranged with their axes in a horizontal plane, are provided with opposed grooves 5, 7 towards one end of the rolls and with opposed grooves 9, 11 towards the other end of the rolls. An endless rubber belt 13 passes over pulleys 15 and 17 which are located, respectively, above and below the rolls, and another endless belt 19 passes over pulleys 21 and 23 also respec tively located above and below the rolls. The belt 13 passes through and fills the grooves 5 and 7 at the nip of the two rolls and the belt 19 passes through and fills the grooves 9 and 11 at the nip of the two rolls. The two belts are spaced apart from each other by the width of the strip to be produced.

Powder is fed to the nip of the rolls from a hopper (not shown) the walls of which extend nearly to the nip, the side walls being formed near to the nip by the belts. With such an arrangement the powder fed from be produced) is contained between the two belts in the region of the nip and thus there is no leakage and spreading of the powder over the surfaces of the rolls beyond the desired width of strip.

Referring to the embodiment shown in Figures 4, 5 and 6 of the drawings each of the two rolls 1 are provide with grooves 5 and 9 (7 and T1 not shown in Figure 4 but shown in Figure 2) in a similar manner to that already described in another embodiment. Mounted on the upper and lower parts of the roll housings 25 and 27 are pulley brackets 29 each supporting two pulleys. The pulley brackets are located directly above and below the nip of the rolls and are soar-ranged that the belts 13 and 19 which pass over pulleys 15, 17, 21 and 23 are in alignment with the grooves 5 and 7, 9 and 11 respectively, at the point where the grooves are opposed at the nip of the rolls. An adjusting device 39 is provided for each of the pulleys 31, 33, 35 and 37 to take up slack in. the belts l3 and 19. The belt 13 passes through the nip of the rolls between the grooves 5 and 7 (see Figure 2), over the pulleys 15, 17, 31, and 33 and between the coupling boxes 41 which transmit the drive to the rolls. In a similar maruier, the belt 19 passes through the nip of the rolls between the grooves 9 and 11 (see Figure 2) and over the pulleys 21, 23, 35 and 37'. Both belts completely fill the gaps formed by the grooves and are compressed about 15 of the cross section at the nip of the rolls.

The belts are not provided with separate driving means but are drawn through the rolls by. rotation of the rolls themselves.

A cross section of a suitable belt is "shown in Figure 5 and is preferably made of rubber. The face 43 may be provided-with steel reinforcement in the form of a flexible steel band covering or partially covering the face and preferably attached to the rubber, for example, as indicated in Figure 5a. The steel band is identified by numeral 42, and there is no critical width of this band 42, except that it must, of course, be less than the width of the face 43a to allow for compression of the rubber. It must also be greater than the largest proposed roll gap, as will be appreciated. Such belts are used with the steel band facing the powder as the belt passes through the grooves in the rolls. If the belt is made from rubber of automobile tyre quality, the steel facing is unnecessary since such rubber has good resistance to abrasion. t

The cross sectional shape of the grooves is not important but it has been found advantageous to use a shape similar 'to that shown in Figure 6. The outer side of the groove is inclined at about from the inner side which is approximately normal to the roll surface. The bottom of the groove is radiussed to avoid stress concentrations in the roll, and the cross section of the groove is smaller than the cross section of the belt in order to compress the belt during the rolling operation.

In operation, powder is fed to the nip of the rolls as described in the previous embodiment and the rotation of the rolls causes the belts to travel over the pulleys and through the gap formed by the opposed grooves. The spread of the powder across the rolls is restricted by the belt and firm, straight edges are producedon the 7 resulting strip.

Referring to the embodiment of the invention shown in Figures 7, 8 and 9 of the drawings, rolls land 3 are provided with grooves 5, 7, 9 and 11, as described in previous embodiments. The grooves 5 and 9 of roll 1 are fitted with rubber bands 45 and 47 which project above the roll surface and engage with'the grooves 7 and 11 respectively of the roll 3. The projection and shape of the rubber bands is such that the bands are compressed in the grooves at the nip of the rolls.

We claim:

1. A rolling mill of the character described for producing metal strip from metal powder, which comprises two rolls arranged so as to provide a nip therebetween, means for feeding metal powder to the nip of the rolls, a pair of opposed circumferential grooves in the two rolls, a second pair of opposed circumferential grooves in the two rolls, and two resilient sealing means, one sealing means substantially filling, at least in the region ofthe nip, one pair of opposed grooves and the other sealing meanssubstantially filling, at least in the region ofthe nip, the second pair of opposed grooves.

2. A rolling mill as claimed in claim 1 in which each resilient sealing means is an endless rubber belt which is mounted on two freely rotatable pulleys and only fills the opposed grooves in the region of the nip.

3. A rolling mill as claimed in claim 2 in which the axis of rotation of each pulley is substantially at right angles to the axes'of rotation of the rolls and the pulley is substantially at right angles to the plane containing the axes of rotation of the rolls.

4. A rolling mill as claimed in claim 1 in which th rubber belts are provided on one face with a steel reinforcernent.

5. A rolling mill as claimed in claim 1 in which each resilient sealing means is a solid rubber band substantially filling one groove of an opposed pair of said grooves and projecting from said one groove by such an amount that it substantially fills the other groove of the opposed pair of grooves in the regionof the nip.

References Cited in the file of patent UNITED. STATES PATENTS 614,269 Great Britain Dec. 13, 1948

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