APPARATUS FOR DIVIDING STRIP MATERIAL

Abstract: An apparatus for dividing strip material, in particular strip-shaped scrap resulting from edge-trimming of rolled strip and metal sheet, comprises at least one pair of mutually co-operating cutters (18, 18a), between which the strip material (14) is fed and which are arranged to penetrate the strip material from mutually opposite sides. The two cutters in each co-operating pair are mutually substantially parallel at the moment of their penetration into the strip material. The one cutter (18) in each pair is arranged to engage the strip material slightly in front of the second cutter (18a), as seen in the direction of movement of the strip material, and then to move away from the second cutter in the direction of movement of the strip material, so that the part of strip material located in front of the cutters is separated from the remainder of the strip material by a combined cutting and tearing operation.

Description: Apparatus for -dividing strip material --. —..-The. present invention -relates to an apparatus for dividing strip material, said apparatus comprising at least one pair of mutually co-operating cutters between which said strip material is continuously advanced and which are arranged to penetrate said material on respective opposite sides thereof. The apparatus is particularly, although not exclusively, intended for use when collecting scrap formed while edge-trimming rolled strip and metal sheet. It is previously known- that handling of scrap formed when''edge-trimming rolled strip and metal sheet can be facilitated by dividing or "chewing" the long strips formed during said edge-trimming operation, thereby to reduce the volume of the scrap. To this end there is normal¬ ly used radial-type chewers which have at least one stationary cutter and at least two movable cutters which are mounted on a rotatable roller. The strip to be divided is fed radially in towards the rotating roller, severing of the strip occurring " between a movable" cutter' and the fixed cutter when said movable. cutter passes by the fixed cutter, which is located adjacent the movement path of the movable cutter. The disadvantages with these prior art chewers . is that their capacity is not sufficiently high to enable the chewers to cope with all the scrap formed in modern metal-strip or metal-sheet mills, when these operate at their maximum speed or at a speed near said maximum. Because of the low capacity of known chewers, the rolling speed of the rolling mill must be maintained at 30-50% beneath their maximum roll speed,. hich greatly decreases the production rate. It is also known to use chewers which comprise two rotatable rolls and steel cutters mounted thereon. In these chewers the cutters must be ground to OMPI special requirements and be very precise in order for the chewers to operate satisfactorily. This results in high maintenance costs. The cutters of these chewers rotate at mutually the same peripheral velocities. Further, the conventional chewers are extremely nois which is a great disadvantage to those persons working in the rolling mill. Although sound-dampening covers can be placed over the chewers, this can normally only be done with great difficulty, since they must be placed beneath the strip or plate, close to the cutting location, where available space is very limited. The main object of the invention is to provide an apparatus for dividing strip material, particularly for dividing up scrap formed when edge-trimming metal strip a metal sheet, which is able to operate at high speeds and which is considerably quieter than previously known apparatuses. This object is achieved with an apparatus according to the invention which comprises at least one pair of mutually co-operating cutters, between which the strip material is fed and which are arranged to penetrate the material from mutually opposite sides, the apparatus bein characterized in that the two cutters in each pair are mutually substantially parallel at the moment of their penetration into the strip material, and that the one cutter in each pair is arranged to engage the strip material slightly in front of the second cutter as seen in the direction movement of the strip material, and then to move away from the second cutter in the direction of-. movement of the strip material, such that the part of str material located in ront of the cutters is separated• from the remainder of the strip by a combined cutting and tearing action. Because, in accordance with the invention, at least one cutter moves substantially in the direction of move¬ ment of the strip material, the strip feed is facilitated OMPI to such an extent that a higher working speed, and there¬ with a higher capacity, can be • reached than was possible with the previously known apparatuses. This increase in capacity is particularly high in those cases when both cutters in the co-operating pair of cutters move substan¬ tially in the direction of movement of the strip material, whereby feeding "" of the material to be chopped up or divided is considerably facilitated. Because one cutter moves away from the other cutter during the dividing operation, whereby the part of the strip material located in front of the cutters is separated by a combined cutting and. tearing operation, there is obtained a considerable reduction in the noise level of the apparatus. The aforementioned advantages are obtained owing to the fact that the apparatus according to the invention operates in accordance with a novel working principle, namely that the metal strip is divided into pieces by means of a combined cutting and tearing operation. This novel working principle also greatly reduces the wear on the apparatus, since it is not subjected to impact forces, or only to substantially smaller impact forces. Neither need the cutters be ground to a special specification, which is necessary in the previously known apparatuses having two rotatable rollers , and they may have the form of index- ible bits, thereby greatly facilitating the exchange of cutting edges and reducing maintenance costs. Two exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a cross-sectional view of one embodi- ment of the apparatus according to the invention, having two rotatable rollers both of which are provided with three steel- cut-ter.s.;. and Figure 2 illustrates a second embodiment of the appa¬ ratus according to the invention, having two rotatable rollers of which one is provided with two steel cutters and the other with three steel cutters. In Figure 1 there is illustrated an apparatus for dividing strip material and comprising two rollers 10,11, each of which is mounted for rotation on a respective shaft 12,13. The shafts 12,13 extend perpendicularly to the plane of the figure. A strip 14 obtained when edge- trimming roll d metal sheet material is fed between the rollers 10,11. The direction of feed is indicated by the arrow 15. The manner in which the rollers 10,11 are jour nalled and driven has not been illustrated, since the structural elements and devices required therefor are of a conventional type and do not form part of the prese invention. Neither have the means required ' for edge- trimming the rolled sheet material and guiding the resulting scrap strip been illustrated" for the same reas The upper roller 10 is arranged to be^ rotated clock wise, as shown by the arrow 16, and is provided with thr steel cutters 17,18,19, which are mounted in the roller a manner such that the trailing edge of each cutter projects slightly beyond the cylindrical surface of the roller. Each of the cutters is held in the roller by mea of a respective clamp 20, 21 and 22, said clamps having the form of wedges and being held on the roller by means of a respective screw 23, 24 and 25. The wedge-shaped clamps are arranged in pockes so formed that said clamps abut one side of the pocket and one side of a respective cutter. The clamps extend radially out to the other edge of the associated cutter. Clearances 26, 27 and 28, respectively, are arranged between the lower part of the clamps and the bottom of the pockets in the roller, in which the clamps are located, such as to enable the clam to be drawn into the roller by means of screws to an ext sufficient to provide sufficient clamping force for the cutters in the roller. The roller is also provided with axially extending clearances 29,30,31 at the bottom of each pocket to enable indexible cutters to be used. The lower roller 11 is arranged for rotation in a OMPI counter clockwise direction, as shown by the arrow 32, and is, in other respects, constructed in the same manner as the upper roller. The roller 11 has three steel cutters 17a, 28a, 19a. One difference, however, is that the 5 working diameter of the lower roller-cutter-unit is approxi¬ mately 10% smaller than the working diameter of the upper roller-cutter unit. The cutters are arranged equi-angularly in the rollers 10,11. The two rollers 10,11 are arranged to 0 rotate synchronously at mutually the same speed of rotation- Because the rollers rotate at the same speed, the cutters in the upper roller will rotate at a slightly higher peripheral velocity than the cutters in the lower roller, since the upper roller-cutter-unit has .a somewhat larger 5 working diameter. The upper roller is so adjusted in rela¬ tion to the lower roller that the cutters in the upper roller lie somewhat in front of the cutters in the lower roller during a separating operation. In the Figure 1 embodiment each roller is provided 0 with three cutters of square cross section. The rollers, however, may equally as well be provided with 1,2,4 or any other suitable number of cutters . If several cutters are arranged on each roller, said cutters must be equi- angularly arranged thereon. 5 In the Figure 2 embodiment the upper roller 33 is provided with two cutters 34,35 and the lower roller 36 with three cutters 37,38,39. The cutters are secured to the rollers in the same way as that described with refe¬ rence to Figure 1. The upper roller is arranged for rota- 0 tion in a clockwise direction and the lower roller in a"" counterclockwise direction, as shown by means of the arrows . .-40,.41-. In- this...embodiment-, however,---. he- roller-cutter-units have mutually the same working diameters and are arranged, to rotate at mutually different speeds; the upper roller 5 must have the higher speed. The ratio between the speeds of revolution of the rollers in the Figure 2 embodiment OMPI must be 3:2', in order for the cutters on the upper roll to co-operate with the cutters on< the lower roller. In both of the illustrated embodiments both, cutters in each pair of co-operating cutters move during a sepa=- rating operation substantially in the direction of move¬ ment of the strip material, thereby facilitating the guiding and ' feeding of the strip, and the upper cutters move at a higher velocity than the lower cutters, those cutters moving at the higher velocity constantly being located, during a dividing operation, in front of those cutters which move at the lower velocity. The rollers are arranged at such a distance aparat that the strip to be chewed-up is unable to pass between the rollers without th edges of the cutters biting into said strip. Thus, at the beginning of a dividing operation, the two mutually co¬ operating cutters penetrate the strip close to one another and from opposite sides of said strip, said strip being partially severed thereby. As the dividing operation proceeds, the distance of the leading cutter from the trailing cutter increases, whereby that part of the strip located in front of the cutters is torn from the remaining part of said strip. Although only two embodiments of the invention have been described and illustrated, it will be understood that many modifications and variations are possible within the scope of the invention. Thus, the rollers of the first embodiment can be arranged to rotate at different speeds and may also be provided with a different number of cutters. The cutters may also have a form different to the illustrated form, e.g. may have in cross section the shape of an isosceles triangle, and may be mounted on the roller in a manner different to that illustrated. When the roller have different working diamters, the di ference may be greater or smaller than the 10% " difference aforementioned. The positions of the rollers may also be changed, so that the cutters which move at the greater speed lie beneath the strip. f OMPI /,, W WIIFFOO The term "strip" as used here also includes rod-like material and wire, and the described apparatus is also suitable for dividing rod-like and wire-like material. - • ^ : . χ tr OMPI

Claims: CLAIMS : 1. An apparatus for dividing strip material, comprising at least -one pair of mutually co-operating cutters (e.g. 18,18.a; 35,37), between which the strip material (14) is fed and which are arranged to penetrate said material fro mutually opposite sides, characterized in that the two cutters (18,18a; 35,37) in each pair are mutually sub¬ stantially parallel at the moment of their penetration into the strip material, and that the one cutter (18;35) in each pair is arranged to engage the strip material slightly in front of the second cutter (18a; 37) as seen in the direction of movement of the strip material, and then to move away from the second cutter (18a; 37) in the direction of movement of said strip material, such that the part of strip material located in frontof the cutters is separated from the remainder of said strip by a combin cutting and tearing operation. 2. An apparatus according to claim 1, characterized in that the cutter (18; 35) arranged to move away from the other cutter (18a; 37) is mounted on a body which is arranged for rotation about an axis which is substantiall perpendicular to the direction of movement of said strip material and which is spaced from said material. 3. An apparatus according to claim 2, particularly for dividing strips of scrap metal obtained when edge-trimmin rolled metal sheet, characterized in that the cutters of each pair (18,18a; 35,37) are each mounted on a respectiv roller (10,11; 33,36) and that said rollers are arranged to rotate in a direction such that the cutters , during a dividing operation, move substantially in the direction of movement (15) of said strip material, one cutter (18,3 during said dividing operation ' being located in front of the other (18a; 37) and moving at a greater peripheral velocity than said other cutter. 4. An apparatus according to claim 3, characterized in that the roller-cutter-units (10,17,18,19; 11,17a,18a,19a) have different working diameters and rotate at mutually the same speed. 5. An apparatus according to claim 3, characterized in . tha-t- he-roller-cutter--units (33.^3-5-;..3£-3,9.)- av .mutually the same working diameters and rotate at mutually different speeds. 6. An apparatus according to claim 4 or 5, characterized in that a plurality of cutters (e.g. 34,35; 37,38,39) are arranged on each roller (33;36) so that several pairs of . mutually co-operating cutters are formed. 7. An apparatus according to claim 4 k , characterized in that three cutters (17,18,19; 17a,18a,19a) are arranged equi-angularly on each roller (10; 11). 8. An apparatus according to claim 5, characterized in that the roller-cutter-unit (33-35) which rotates at the higher speed has fewer cutters than the other roller-cutter- units (36-39), the speeds at which the two roller-cutter- units rotate being so selected that one pair of mutually co-operating cutters is constantly formed each time a cutter engages the strip material (14) . 9. An apparatus according to claim 3, characterized in that.the cutters (17,17a,18,18a,19,19a,33-39) comprise steel rods of square cross section, and that said rods are removably mounted in the rollers (10,11,33,36) in a manner such that the cutter moving at the higher peripheral velocity (10,17,18,19; 33-35) has its rear, outer edge,-as seen in the direction of rotation of the associated roller,- and- the- cutter moving at the..lower.,.peripheral velocity (ll,17a,18a,19a;36-39) has its leading, outer edge, as seen in the direction ' of rotation of the associated, oller, projecting out beyond the cylindrical surface of the associated roller, said outwardly pro¬ jecting edges of the cutters being used to divide said strip. O PI 10. An apparatus according to claim 4, characterized in that the larger roller-cutter-unit (10,17,18^19) has a working diameter whic -is approximately 10% greater th the working diameter of the smaller roller-cutter-unit (11,17a,18a,19a). ' * ' OMPI

Inventors: IVINGER K
Applicants: GRAENGES ALUMINIUM AB, IVINGER K
Application year: 1979
Main classification: B23D25
IPC codes: B23D25, B23D35, B26D7