METHOD AND APPARATUS FOR THE REMOVAL OF REINFORCEMENT BEADS FROM PNEUMATIC TYRES

Abstract: The apparatus includes a roller track (10) for supporting a tyre (15) for rotation about a horizontal axis. A cutting head (16, 17) is movable onto a position in which a cutting blade (23) is located in register with a part of the side wall of the tyre (15) adjacent the bead (13, 14). The blade (23) is reciprocated so that it cuts through the side wall of the tyre (15) and step-wise rotation of the tyre (15) is effected followed by reciprocal movement of the blade (23) until the bead (16, 17) has been completely severed from the side wall of the tyre (15).

Description: METHOD AND APPARATUS FOR THE REMOVAL OF REINFORCEMENT BEADS FROM PNEUMATIC TYRES Field of the Invention This invention relates to a method and apparatus for the removal of reinforcement beads from pneumatic tyres. Background to the Invention In order for the material of pneumatic tyres to be recycled or used as fuel, it is necessary to remove the wire reinforcement beads, which are contained in the edges of the tyres which contact the seating areas of the wheels onto which the tyres are fitted. A method and apparatus for this purpose are described in PCT Application No. PCT/GB 98/03740, Publication No. WO 99/30878, to which reference should be made. The method described in said PCT application includes the following steps:- a) placing a tyre on an annular tyre support bed, b) urging the side walls of the tyre to ether and against a first cylindrical cutter surrounded by the annular tyre support bed, c) urging a second cylindrical cutter axially towards the tyre and the first cylindrical cutter, and d) continuing the movement of the second cylindrical cutter until it has passed completely through the tyre and has entered the first cylindrical cutter, thereby severing the beads from the tyre. A disadvantage of the method described in said PCT application is that the two cylindrical cutters, which are expensive to produce, can be used for only one size of tyre. It is accordingly an object of the present invention to provide an improved method and apparatus for removing reinforcement beads from pneumatic tyres. A more specific object of the present invention is to provide a method and apparatus for removing reinforcement beads from pneumatic tyres of a number of different sizes. Summary of the Invention According to a first aspect of the present invention there is provided a method of removing a reinforcement bead from a pneumatic tyre, the method including the following steps:- a) positioning the tyre for rotation about a predetermined axis, b) providing a cutting head which includes a reciprocable blade, c) moving the cutting head into a position in which the blade is located in register with a part of the side wall of the tyre adjacent the bead, d) effecting reciprocation of the blade so that it cuts through the tyre side wall, e) effecting stepwise rotation of the tyre about said axis, f) effecting further reciprocal movements of the blade between successive rotational movements of the tyre, and g) continuing steps e) and f) until the bead has been completely severed from the side wall of the tyre. Two cutting heads are preferably provided, one for removal of each of the reinforcement beads from the tyre. The two cutting heads are preferably arranged to act on diametrically opposite parts of the side walls of the tyre. According to a second aspect of the present invention there is provided apparatus for removing a reinforcement bead from a pneumatic tyre, the apparatus including:- a) support means for supporting a tyre for rotation about a predetermined axis, b) a cutting head which includes a reciprocable blade, c) means for moving the cutting head into a position in which the blade is located in register with a part of the side wall of the tyre adjacent the bead, d) means for effecting reciprocation of the blade so that it cuts through the side wall of the tyre, and e) control means controlling operation of the apparatus whereby step-wise rotation of the tyre is effected about said axis followed by reciprocal movement of the bead, until the bead has been completely severed from the side wall of the tyre. As mentioned above, two cutting heads are preferably provided, one for removal of each of the reinforcement beads from the tyre. The two cutting heads are preferably arranged to act on diametrically opposite parts of the side wall of the tyre. The two cutting heads are preferably pivotally mounted on frames located one on each side of the operational position occupied by the tyre while the bead removal operation is being carried out, each of the cutting heads being arranged for movement between a retracted position, in which it is clear of the path of movement of a tyre into and out of its operational position, and a working position, in which reciprocation of the associated blade is effected to cut through the respective side wall of the tyre. The cutting heads are preferably arranged for pivotal movement about horizontal axes. The tyre is preferably arranged for rotation about a substantially horizontal axis, being supported on driven rollers which are arranged to rotate for a predetermined length of time, to effect rotation of the tyre, between successive reciprocal movements of the blades, through an angle such that each succeeding cut formed in a side wall of the tyre overlaps the previous cut by a small predetermined amount. The control means for controlling operation of the apparatus is preferably such that the length of each period of time for which the rollers are driven is adjustable in dependence on the size of the tyre. The control means is also preferably such that the vertical spacings between the support surfaces of the rollers on which the tyre is supported and the axes about which the cutting heads are arranged for pivotal movement are also adjustable in dependence on the size of the tyre. Brief Description of the Drawings Figure 1 is a schematic view showing a stage in the removal of the reinforcement beads from a pneumatic tyre, Figure 2 is a diagrammatic view of one of the cutting heads which form part of the apparatus used for removing the reinforcement beads from the tyres, Figure 3 shows a blade which forms part of the cutting head of Figure 2, and Figure 4 is a diagrammatic perspective view of the apparatus. Description of the Preferred Embodiment As shown in the drawings, a powered roller track 10 is located between a pair of frames 11 and 12 which control the control means and the drive means for performing the various functions involved in removing the reinforcement beads 13 and 14 from a pneumatic tyre 15. A first cutting head 16 is mounted on frame 11 and a second cutting head 17 is mounted on frame 12. The constructions and modes of operation of the two cutting heads 16 and 17 are the same, as described below. The first cutting head 16 is mounted for pivotal movement relative to frame 11 about a horizontal axis 18 and is movable about the axis 18 between an operational position (as shown in Figure 1 ) and a retracted position (turned clockwise from the position shown in Figure 1) in which the cutting head 16 is contained within the confines of frame 11 and is thus clear of the path of movement of the tyre 15 into and out of the space between the two frames 11 and 12. The second cutting head 17 is mounted for pivotal movement relative to frame 12 about a horizontal axis 19 and is movable about the axis 19 between an operational position (as shown in Figure 1) and a retracted position (again turned clockwise from the position shown in Figure 1 ) in which the cutting head 17 is contained within the confines of frame 12 and is thus clear of the path of movement of the tyre 15 into and out of the space between the two frames 11 and 12. Movements of the cutting heads 16 and 17 about the axes 18 and 19 are effected by pneumatically-operated rotary actuators (not shown), with the angle through which each cutting head 16, 17 is moved being adjustable in dependence on the diameter of the tyre 15 and the height of the side wall of the tyre 15. At the beginning of a cycle of operations, the two cutting heads 16 and 17 are in their retracted positions. The tyre 15 is then advanced into position on the roller track 10 and the cutting heads 16 and 17 are swung into their operational positions by the pneumatic rotary actuators. After the beads 13 and 14 have been cut away from the side walls of the tyre 15 (as described below), the cutting heads 16 and 17 are swung back into their retracted positions in readiness for the next cycle of operations. As shown in Figure 2, each of the cutting heads 16, 17 includes a base 20, which is formed with a bore in which a flanged bush 21 is fitted. The flanged bush 21 receives a pivot pin (not shown) for mounting the cutting head 16, 17 on the respective frame 11 , 12. When cutting head 16 is in its operational position, as shown in Figure 1 , the working parts of the cutting head 16 are disposed above the base 20 of the head 16 for engagement with that part of the adjacent side wall of the tyre 15 which is at the highest point of the circumference of the bead 13. On the other hand, when cutting head 17 is in its operational position, the working parts of the cutting head 17 are disposed below the base 20 of the head 17 for engagement with that part of the adjacent side wall of the tyre 15 which is at the lowest point of the circumference of the bead 14, i.e. cutting is effected simultaneously at two diametrically opposite positions. Although the cutting heads 16 and 17 are shown in Figure 1 and referred to above as acting on the top and bottom portions of the tyre 15, they are preferably arranged to act at the same vertical level on the fore and aft portions respectively of the tyre 15. A double-acting hydraulic cylinder 22 is mounted on the base 20 and the piston of said cylinder 22 is connected to a blade 23 which comprises a blade holder 24 and a hardened blade tip 25 releasably mounted on the blade holder 24. The blade tip 25 is removable for resharpening purposes and/or for replacement by a new blade tip 25. The blade holder 24 and the blade tip 25 together form the blade 23 which is guided during its travel by passage through a guide opening formed in a combined split blade guide and stripper 26 mounted on the base 20. At the limit of the travel of the double-acting cylinder 21 , the blade tip 25 enters a slot 27 in a wall 28 extending from the base 20 at the end thereof remote from the flanged bush 21. When a cutting head 16, 17 is moved into position in readiness for a cutting operation, the cutting blade 23 will be in its retracted position, in which it does not project beyond the blade guide and stripper 26 and the head 16, 17 will be so positioned relative to the adjacent side wall of the tyre 15, that the wall 28 is located on one side of the tyre bead 13 or 14 and the blade guide or stripper 26 is located on the other side of the tyre bead 13 or 14 (as shown in Figure 1). Once the cutting head 16, 17 has been moved into its operational position, the double-acting cylinder 22 is actuated to effect advancing movement of the cutting blade 23 so that the blade tip 25 will pass through the side wall of the tyre 15 adjacent the bead 13 or 14 and enter the slot 27 in the wall 28. Once the blade tip 25 has been advanced to its full extent, the direction of action of the cylinder 22 is reversed and the cutting blade 23 is moved back positively to its original position clear of the side wall of the tyre 15. Substantial flexing of the tyre bead 13, 14 may occur as the blade tip 25 passes through the side wall of the tyre 15 and is then retracted. Accordingly, in order to reduce friction, a series of rollers (not shown) may be mounted on the base 20 at positions such that they will be engaged by the circumference of the tyre 15. A power unit 29 is provided for driving the powered roller track 10 via a chain drive system 30 and the arrangement is such that, once the blade tip 25 has been returned to its original, retracted position, the power unit 29 is actuated to cause the rollers of the track 10 to rotate and thereby effect rotation of the tyre 15 about its horizontal axis. The extent of angular rotation of the tyre 15 is small and is such that, when the next cycle of operations of each cutting head 16, 17 is effected to make a further cut in the adjacent side wall of the tyre 15, there will be a small amount of overlap with the previous cut. This ensures that any small wires left intact on the previous cut are severed. The apparatus includes a timing programme which is set in dependence on the size of the tyre and determines the angular extent through which the tyre is rotated between successive cutting operations. The process of cutting and incremental rotation continues until both beads 13 and 14 have been completely severed from their respective side walls of the tyre 15. Due to their weight and rigidity, the cut beads 13 and 14 remain in the tyre 15 while it is in its vertical condition. Thus, once a complete cycle of operations has been effected, to sever the beads 13 and 14 from the tyre side walls, the tyre 15 (and with it the beads 13 and 14) is transferred to a further station at which removal of the beads 13 and 14 is effected. A typical cycle of operations will take less than three minutes to complete, providing an output of at least twenty cut tyres per hour, even with the toughest of tyres. The powered roller tract 10 on which each tyre 15 is supported while cutting of the tyre side walls is effected is adjustable in height in dependence on the diameter of the tyre being treated. Thus, the rollers of the powered track 10 are mounted on a bed 31 which is movable vertically between a pair of side frame members 32 and 33 and is connected to the piston 34 of a pneumatic or hydraulic unit 35. As each tyre 15 is being moved into position in readiness for a cycle of operations to be carried out, the operator of the apparatus will measure the diameter of the tyre 15 and will set the timing programme accordingly. Such setting of the timing programme will also serve to set the rollers of the powered track at the required height. Alternatively, of course, a measurement station may be provided in advance of the cutting station so that measurement of each tyre is effected automatically before it reaches the cutting station so that setting of the timing programme and of the height of the powered track 10 will also be effected automatically. An important advantage of the method and apparatus of the present invention as compared to what is described in Specification No. WO 99/30878 referred to above is that the cutting tools which are required can readily be resharpened and/or replaced and that no changes are required to the cutting heads 16 and 17 to accommodate tyres of different diameters.

Claims: Claims:- 1. A method of removing a reinforcement bead from a pneumatic tyre, the method including the following steps:- a) positioning the tyre for rotation about a predetermined axis, b) providing a cutting head which includes a reciprocable blade, c) moving the cutting head into a position in which the blade is located in register with a part of the side wall of the tyre adjacent the bead, d) effecting reciprocation of the blade so that it cuts through the tyre side wall, e) effecting stepwise rotation of the tyre about said axis, f) effecting further reciprocal movements of the blade between successive rotational movements of the tyre, and g) continuing steps e) and f) until the bead has been completely severed from the side wall of the tyre. 2. A method as claimed in Claim 1 , in which two cutting heads are provided, one for removal of each of the reinforcement beads from the tyre. 3. A method as claimed in Claim 2, in which the two cutting heads are arranged to act on diametrically opposite parts of the side walls of the tyre. 4. Apparatus for removing a reinforcement bead from a pneumatic tyre, the apparatus including:- a) support means for supporting a tyre for rotation about a predetermined axis, b) a cutting head which includes a reciprocable blade, c) means for moving the cutting head into a position in which the blade is located in register with a part of the side wall of the tyre adjacent the bead, d) means for effecting reciprocation of the blade so that it cuts through the side wall of the tyre, and e) control means controlling operation of the apparatus whereby step-wise rotation of the tyre is effected about said axis followed by reciprocal movement of the bead, until the bead has been completely severed from the side wall of the tyre. 5. Apparatus as claimed in Claim 4, in which two cutting heads are provided, one for removal of each of the reinforcement beads from the tyre. 6. Apparatus as claimed in Claim 5, in which the two cutting heads are arranged to act on diametrically opposite parts of the side wall of the tyre. 7. Apparatus as claimed in Claim 6, in which the two cutting heads are pivotally mounted on frames located one on each side of the operational position occupied by the tyre while the bead removal operation is being carried out, each of the cutting heads being arranged for movement between a retracted position, in which it is clear of the path of movement of a tyre into and out of its operational position, and a working position, in which reciprocation of the associated blade is effected to cut through the respective side wall of the tyre. 8. Apparatus as claimed in any one of Claims 5 to 7, in which the tyre is arranged for rotation about a substantially horizontal axis, being supported on driven rollers which are arranged to rotate for a predetermined length of time, to effect rotation of the tyre, between successive reciprocal movements of the blades, through an angle such that each succeeding cut formed in a side wall of the tyre overlaps the previous cut by a small predetermined amount. 9. Apparatus as claimed in Claim 8, in which the control means for controlling operation of the apparatus is such that the length of each period of time for which the rollers are driven is adjustable in dependence on the size of the tyre. 10. Apparatus as claimed in Claim 8 or Claim 9, in which the control means is such that the vertical spacings between the support surfaces of the rollers on which the tyre is supported and the axes about which the cutting heads are arranged for pivotal movement are adjustable in dependence on the size of the tyre. 11. Apparatus as claimed in Claim 5, in which each blade includes a blade holder and a removable, replaceable blade tip.

Inventors: TOLAND JOSEPH, TOLAND, JOSEPH
Applicants: TOLAND JOSEPH, TOLAND, JOSEPH
Application year: 2000
Main classification: B26D1
IPC codes: B26D1