Deburring shear
FIELD OF THE INVENTION 
     The present invention relates to a device and process to be used in the treatment of steel, and, more specifically, to a device and process for deburring steel. 
     BACKGROUND OF THE INVENTION 
     Steel usually is manufactured in long slabs commonly called parent slabs. Due to their lengths, these parent slabs are very difficult to handle and transport, and, in order to make the steel available for use or for further processing in a plate mill, the parent slabs must be cut into shorter, more easily transportable slabs. The most commonly used method of cutting the parent slabs involves the use of a flaming torch. This method, which is called torch cutting, is very effective, except that it leaves residue on the steel where the cut was made in the form of torch dross or slab burr. This residue is an imperfection that must be removed prior to using the steel slabs or running them through a plate mill. 
     Accordingly, various methods and devices have been developed for removing this residue. A well known device is a hydraulically-operated assembly comprising a table, a knife and a rotatable pinch roll. The table comprises a plurality of axially-spaced rolls. The pinch roll is generally cylindrical and extends along the width of the table. The slab of steel is positioned on the table above the knife assembly, and is held in position by the pinch roller, which rests on top of the slab. The pinch roll and the table rolls are then rotated by a driving mechanism, causing the slab to traverse along the table, until the end of the slab passes over the knife shearing off the dross. The direction of rotation of the pinch roll and table rolls is then reversed so that the dross on the opposite end of the slab can be deburred. The cutting action effected by this device is not always effective, especially where the dross is heavy, because the lateral force applied by the pinch roll and table rolls is not always sufficient. 
     The knife used with this well known device comprises two single edges that face opposite directions along the table. Each edge is usually oriented at an angle relative to the direction of travel of the slab and being approximately in the same plane as the table. This orientation allows the knife to make what is called a progressive cut. 
     Accordingly, it is an object of this invention to provide a device and process for deburring steel that improves upon the prior art. 
     It is a further object of this invention to provide such a device and process that can deburr opposite edges of steel slab more effectively through the use of a pair of arms which are adapted to function not only as pinch rolls but also as pusher arms. 
     It is a still further object of this invention to provide a shearing knife assembly that improves upon the shearing knife heretofore known. 
     SUMMARY OF THE INVENTION 
     In accordance with these and other objects, a device for deburring steel is provided that comprises a pair of arms, a pair of carriage assemblies supported by a frame, a table assembly comprising two tables, and a knife assembly. Each arm preferably is pivotally mounted to one of the carriage assemblies by a bracket and by a pair of hydraulic cylinders, and each arm and its corresponding carriage assembly extend over one of the tables. Each arm comprises a pair of supports which terminate at their distal end in an assembly comprising a pinch roll adapted to be rotatably driven by drive shafts or the like and a pusher wall. The longitudinal axis of the pinch roll and the pusher wall when in use extend perpendicular to the direction of travel of the slab, and are adapted to move in the vertical and horizontal directions. 
     The carriage assemblies comprise a plurality of wheels received by the frame so that the carriage assemblies and their corresponding arms are adapted to traverse laterally. Accordingly, each arm is adapted to pivot and move laterally and vertically to alternately act as a pinch roller and a pusher arm to consecutively deburr opposite ends of a slab of steel. 
     Preferably, the table assembly comprises two tables that are separated by the knife assembly, and each table comprises a plurality of rotatable, axially-spaced table rolls, which accommodate the lateral movement of the slab of steel along the tables. The table rolls are rotatably driven in any suitable manner such as by mitre gears or the like. 
     In the preferred embodiment, the knife assembly comprises a plurality of knives mounted to the top of a housing by a common head. A mechanism is included in the housing that is adapted to raise and lower the common head, so that the knives can be raised to the level of the two tables when the dross is to be sheared off the slab and lowered below the table assembly so that the slab can be traversed unobstructed along the table assembly. Preferably, the knives are generally rectangular, are aligned in a side-by-side relationship, and are oriented at a slight angle relative t the longitudinal axis of the table when both are approximately in the same plane. In addition, each knife is offset relative to its adjacent knives in a progressive manner. 
     The knife assembly in accordance with the preferred embodiment has two advantages. First, not only does the entire assembly provide a progressive cut, but each individual knife, because of its orientation, can make its own progressive cut. Second, because each knife is aligned adjacent one another, there are no gaps in the cutting surface. 
     The method of operation is as follows. In the initial position, the arms and the pinch rolls and pusher walls extend above the table assembly, and the knife assembly is in the lowered position below the upper surface of the table. A slab of steel is laid on the first table, and the table rolls are then rotatably driven, causing the slab to be traversed in a forward direction across the table assembly, until the leading edge of the slab rests on the second table. The rolls are stopped. Both pinch rolls and pusher arms first and second arms are lowered, preferably by two pairs of first hydraulic cylinders, so that the first pinch roll comes into contact with and applies a downward pressure on the slab and the second push wall is located adjacent the leading end of the slab. The first and second arms pivot to accommodate the lowering of the pinch rolls and pusher arms. At the same time, the knife assembly is raised so that the knives come into contact with the bottom of the slab. 
     The second arm, driven by the carriage assembly and a pair of hydraulic cylinders connected to the carriage assembly, then functions as a pusher arm and its second pusher wall pushes the slab in the reverse direction across the knife assembly, while at the same time the pinch roller of the first arm exerts a downward pressure on the slab. In addition, the first pinch roller and the table rolls are activated to simultaneously rotate to accommodate the lateral movement of the slab. As the leading end of the slab is pushed across the knife assembly, the dross on the leading edge of the slab is sheared off in a progressive manner by the knives. The table rolls and first pinch roll drives and the knives lowered are stopped. 
     Both pinch rolls and pusher walls of the arms are then raised above the slab by the first hydraulic cylinders, causing the first and second arms to pivot, and the table rolls are rotated so that the slab is again traversed in the forward direction until most of the slab is located on the second table. Then the table rolls are stopped. The pinch roll and pusher wall of the first arm are then lowered by the first hydraulic cylinders to a position where the first pusher wall is adjacent the tail end of the slab, and the pinch roll and pusher wall of the second arm are lowered also by the first hydraulic cylinders so that the second pinch roll comes into contact with the slab and applies a downward pressure. The first and second arms pivot to accommodate the lowering of their pinch rolls and pusher arms. The knife assembly is then raised again so that it comes into contact with the bottom of the slab. 
     The first arm, driven by its carriage assembly and the second hydraulic cylinders connected to the carriage assembly, then functions as the pusher arm and its pusher wall pushes the tail end of the slab forward across the knife assembly. At the same time, the second arm functions as the pinch roller, and its second pinch roller and the table rolls are simultaneously rotating to accommodate the lateral movement of the slab. As the tail end of the slab passes over the knife assembly, the dross on the tail end of the slab is progressively sheared off by the knife assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing invention and its advantages may be readily appreciated from the following detailed description of a preferred embodiment, when read in conjunction with the accompanying drawings in which: 
     FIG. 1 is a top plan view of a deburring shear in accordance with the preferred embodiment of the invention. 
     FIG. 2 is a cross section taken along lines 2--2 of FIG. 1. 
     FIG. 3 is a side plan view of the deburring shear of FIG. 1. 
     FIG. 4 is a cross section taken along lines 4--4 of FIG. 1. 
     FIG. 5 is a top view of one of the two arms employed in the deburring shear of FIGS. 1-4. 
     FIG. 6 is a cross section of a preferred embodiment of the knife assembly employed in the deburring shear of FIGS. 1-4. 
     FIGS. 7(a)-7(f) are a sequence of schematics illustrating the various steps of the deburring shear process in accordance with the invention. 
     FIG. 8 is a cross section view of one embodiment of the knife assembly of the invention. 
     FIG. 9 is a top plan view of the knife assembly of FIG. 5. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with the preferred embodiment of the invention shown in FIGS. 1-4, a steel deburring device 10 is provided comprising first and second arms 12, 12A, a table assembly 16, and a knife assembly 18. First and second arms 12, 12A are each adapted to pivot and move laterally and vertically to alternately function as a pinch roller and a pusher arm. 
     Table assembly 16 preferably comprises first and second tables 24, 26 separated by knife assembly 18, and each table comprises a plurality of axially-spaced, rotatably-driven table rolls 28 adapted to traverse the slab of steel across the tables in either direction during the deburring process. First and second tables 24, 26 are known steel slab tables, and rolls 28 are appropriately mounted in any suitable manner for rotation. The rolls are driven by a drive 28A that is shown schematically in FIG. 2. The drive 28A is for all the rollers 28 even though it is only shown connected to the end rollers. 
     As shown in FIGS. 1-5, first arm 12 comprises a pair of first arm supports 13, and a cylindrical pinch roll 20 and a pusher wall 22 mounted to the ends of the supports. Both the cylindrical pinch roll 20 and a pusher wall 22 extend along the width of the table assembly. The pinch rolls are rotatably mounted to the first arm supports in any suitable manner, such as by spherical bearings, and are adapted to be rotatably driven in either direction by any suitable means. In the preferred embodiment, for example, the roll 20 is connected to a first drive shaft 50. The drive shaft 50 is rotatably driven by electrical motor 52 and gear reducer 56, which are mounted on a support base 58. Brake 59 should also be included with the motor. Desirably, pusher wall 22 is oriented at a right angle to the table assembly when its arm is functioning in its pushing mode. 
     Second arm 12A comprises a pair of second arm supports 13A, and a cylindrical pinch roll 20A and a pusher wall 22A mounted to the ends of the supports. Both the cylindrical pinch roll 20A and pusher wall 22A extend along the width of the table assembly. The pinch rolls are rotatably mounted to the second arm supports in any suitable manner, such as by spherical bearings, and are adapted to be rotatably driven in either direction in by any suitable means. In the preferred embodiment, for example, the roll 20A is connected to a second drive shaft 50A. The second drive shaft 50 is rotatably driven by electrical motor 52A and gear reducer 56A, which are mounted on support base 58. Brake 59A should also be included with the motor. Desirably, pusher wall 22A is oriented at a right angle to the table assembly when its arm is functioning in its pushing mode. 
     An elevated frame 30 extends over table assembly 16 and is supported in any suitable manner, such as by a super structure 100 in the form of front end steel wide flange beams 102, a pair of back end steel wide flange beams 104, and a pair of angled steel wide flange beams 106, as shown best in FIGS. 1 and 3. Front end and back end wide flange beams 104, 106 straddle the width of the table assembly, but the table assembly extends lengthwise beyond the super structure. Frame 30 preferably is rectangular and is defined by beams 120, 122, 124 and 126. 
     Disposed within elevated frame 30 are first and second carriage assemblies 74, 76, which are adapted to effect the horizontal movement of the first and second arms 12, 12A and which preferably are driven by two pairs of hydraulic cylinders 42, 42A as shown in FIGS. 1 and 2. 
     The first arm 12 is pivotally connected to first carriage assembly, and the first arm and first carriage assembly extend over the first table. The first carriage assembly is adapted to traverse laterally a distance along frame 30 sufficient to enable an end of a slab of steel to pass over the knife assembly. 
     In the preferred embodiment, first carriage assembly comprises a rectangular steel structure comprising two carriage beams 302, 303 and two side beams 304, 305 that are interconnected by a pair of arm beams 306 and cross beams 308. The first carriage assembly 74 is mounted to the frame 30 by a plurality of wheels 310 rotatably mounted on the carriage beams 302 by any suitable means, such as by axles. Preferably, one pair of wheels 310 is mounted to each carriage beam. As shown best in FIGS. 1 and 2, the wheels 110 are adapted to be received within tracks 108 formed on the two opposed beams 120, 122 of frame 30. 
     Accordingly, wheels 110 and tracks 108 enable first carriage assembly 74 and first arm 12 to traverse laterally along the frame 30 in response to the force of the hydraulic cylinders 42, which connect the first carriage assembly to the frame. Preferably, the wheels 110 are 12 inches in diameter, and the tracks are complimentary in size. 
     Preferably, a pair of vertical brackets 140 is integral with the first carriage assembly and connects the first arm 12 and hydraulic cylinders 42 to the first carriage assembly. The vertical bracket comprises a top portion 142 that rigidly connects the hydraulic cylinders to the first carriage assembly 74, and a bottom portion 144 that pivotally connects first arm 12 to the first carriage assembly. The pivotal connection of the first arm to the first carriage assembly enables the first arm to pivot during the deburring process. 
     In addition, an equalizer shaft 72 should be included to ensure that pusher wall 22 is maintained at a right angle to the top of the table assembly 16 when the first arm is functioning in the pusher mode. Preferably, two arms 73 are pivotably mounted to the equalizer shaft, and to carriage beam 303 of the first assembly by links 170. Equalizer shaft 72 interconnects the first carriage assembly to wide flange beams 102. 
     Pivotally mounted on beam 302 of the first carriage assembly 74 are a pair of hydraulic cylinders 40 that are mounted on a trunnion mount 75 to the distal end of first arm 12. The vertical movement of the first arm 12 is effected by these hydraulic cylinders. 
     The second arm 12A is pivotally connected to second carriage assembly 76, and the second arm and second carriage assembly extend over the second table. The second carriage assembly is adapted to traverse laterally a distance along frame 30 sufficient to enable an end of a slab of steel to pass over the knife assembly. 
     In the preferred embodiment, the second carriage assembly comprises a rectangular steel structure comprising two carriage beams 302A, 303A and two side beams 304A, 305A that are interconnected by a pair of arm beams 306A and cross beams 308A. The second carriage assembly 76 is mounted to the frame 30 by a plurality of wheels 310A rotatably mounted on the carriage beams 302A by any suitable means, such as by axles. Preferably, one pair of wheels 310A is mounted to each carriage beam As shown best in FIGS. 1 and 2, the wheels 110A are adapted to be received within tracks 108A formed on the two opposed beams 120A, 122A of frame 30. 
     Accordingly, wheels 110A and tracks 108A enable second carriage assembly 76 and second arm 12A to traverse laterally along the frame 30 in response to the force of the first hydraulic cylinders 42A, which connect the second carriage assembly to the frame. Preferably, the wheels 110A are 12 inches in diameter, and the tracks are complimentary in size. 
     Preferably, a pair of vertical brackets 140A is integral with the second carriage assembly and connects the second arm 12A and hydraulic cylinders 42A to the second carriage assembly. The vertical brackets 140A comprise a top portion 142A that rigidly connects the hydraulic cylinders 42A to the second carriage assembly, and a bottom portion that pivotally connects the second arm 12A to the second carriage assembly. The pivotal connection of the second arm to the second carriage assembly enables the second arm to pivot during the deburring process. 
     In addition, an equalizer shaft 72A should be included to ensure that pusher wall 22A is maintained at a right angle to the top of the table assembly 16 when the second arm is functioning in the pusher mode. Preferably, two arms 73A are pivotably mounted to the equalizer shaft which is mounted to carriage beam 303A of the first assembly by links 170A. Equalizer shaft 72A interconnects the second carriage assembly to wide flange beams 104. 
     Pivotally mounted on beam 302A are a pair of hydraulic cylinders 40A that are mounted on a trunnion mount 75A to the distal end of second ar 12A. The vertical movement of the second arm 12A is effected by these hydraulic cylinders. 
     In the preferred embodiment, hydraulic cylinders 40A, 40A are 5 inch diameter bore cylinders with a 12 inch stroke, and hydraulic cylinders 42, 42A are 8 inch bore cylinders with a 30 inch stroke. 
     In accordance with the preferred embodiment of the invention, knife assembly 18 comprises a plurality of knives 32 mounted to a common head 34 on the top of a vertical slide plate 500, as shown in FIG. 8. The knives are constructed of heat treated tool steel. A mechanism is included in the housing that is adapted to raise and lower the common head, so that the knives can be raised to the level of tables 24, 26 when the dross is to be sheared off the steel slab and lowered below the table assembly so that the slab can be traversed unobstructed along the table assembly. Mechanism 38 may be operated in any suitable manner, but, preferably, it comprises a 5 inch diameter bore hydraulic cylinder 88 adapted to raise and lower common head 34. If desired, the housing may be shrouded by a steel plate 60 in order to keep the dross out of the housing. 
     Common head 34 is mounted to a trunnion block 400 which is mounted within a machined seat 502 formed on the bottom of the common head. A bore 404 extends through the common head and trunnion block through which a pivot shaft 406 extends. Pivot shaft 406, which is either manually or automatically controlled through an electronic control system, permits the common head to align itself against the bottom of the slab to compensate for any chamber inherent in the slab. Because of this construction, knives 32 are separately pivotable and separately elevatable. 
     As shown best in FIGS. 1 and 9, knives 32 may be generally rectangular and are aligned in a side-by-side relationship. The knives 32 are oriented at a slight horizontal angle relative to the long axis of the table, so that a pair of oppositely-facing corner edges effect the cutting. In addition, each knife 32 is offset relative to its adjacent knives in a progressive fashion, as shown, to enhance the cutting ability of the knife assembly. Knives 32 are mounted to head 34 in any suitable manner such as by bolts 98. 
     The knife assembly in accordance with the preferred embodiment has two advantages. First, not only does the entire assembly provide a progressive cut, but each individual knife, because of its orientation, can make its own progressive cut. Second, because each knife is aligned adjacent one another, there are no gaps in the cutting surface. 
     In the preferred embodiment, the deburring shear 10 is hydraulically driven and is operated by an electronic control system. The steps of operation are illustrated schematically in FIGS. 7(a)-7(f). Initially, first and second arms 12, 12A are in the raised position and located above table assembly 16, and knife assembly 18 is in the lowered position so that knives 32 are located below table rolls 28. After a slab of steel 66 is laid on first table 24, the table rolls are rotated causing the slab to traverse across the table assembly until the leading end of the slab rests on the second table. (See FIG. 7(a)). Pinch roll 20 and pusher arm 2 are then lowered by hydraulic cylinders 40 and the first arm pivots so that the pinch roll 20 comes into contact with and applies a downward pressure to the slab, and pinch roll 20A and pusher wall 22A of the second arm 12A are lowered by hydraulic cylinders 40A and the second arm pivots so that the pusher wall 22A is immediately adjacent the leading end of the slab. At the same time, knife assembly 18 is raised so that the knives come into contact with the bottom of the slab. (See FIG. 7(b)). Second arm 12A, driven by second carriage assembly 76 and hydraulic cylinders 42A, then functions as a pusher arm and its corresponding pusher wall 22A pushes the slab back across the knife assembly, while at the same time first arm 12 functions as a pinch roller and applies a downward pressure on the slab. In addition, pinch roll 20 of first arm 12 and table rolls 28 are simultaneously rotating in the reverse direction to accommodate the traversing slab. As the edge of the leading end of the slab is pushed across the knife assembly, the dross on the edge of the slab is sheared off by the knives. (See FIG. 7(c)). 
     First and second arms 12, 12A are then pivoted and raised above slab 66 by the hydraulic cylinders 40, and table rolls 28 are rotated in the forward direction causing the slab to traverse in a forward direction a further distance down the table assembly 16 until a portion of the tail end of the slab is located on the first table. (See FIG. 7(d)). The pusher wall 22 of first arm 12 is then lowered to a position adjacent the tail end of the slab, and pinch roll 20A of second arm 12A is lowered so that it comes into contact with the slab above the second table. At the same time, knife assembly 18 is raised again so that it comes into contact with the bottom of the slab. (See FIG. 7(e)). 
     First arm 12, driven by first carriage assembly 74 and hydraulic cylinders 42, then functions as the pusher arm and with its corresponding pusher wall 2 pushes the slab forward across the knife assembly, while at the same time second arm 12A functions as a pinch roller as it applies a downward pressure on the slab and its pinch roller 20A and table rolls 28 are rotating to accommodate the lateral movement of the slab. As the tail end of the slab passes over the knife assembly, the dross on the tail end of the slab is sheared off by the knife assembly. (See FIG. 7(f)). The deburred slab is then ready for use or the next step of the steel treatment process. 
     The foregoing description is for purposes of illustration only and is not intended to limit the scope of protection accorded this invention. The scope of protection is to be measured by the following claims, which should be interpreted as broadly as the inventive contribution permits.