Patent GB-891626-A (GB)
Title: Improvements in and relating to sidewall buffing of pneumatic tires
Filed: 1959-01-29
Abstract: 891,626. Buffing tyres. SCHRANK, E. P. Jan. 29, 1959, No. 3270/59. Class 60. [Also in Group XXXVII] Apparatus for buffing a sidewall portion of a pneumatic tyre T comprises means M-1, 18 for rotating the tyre about an axis, mounting means 39, 42 for a sidewall buffing element 36 permitting the element to move into and out of contact with the tyre sidewall and conform to the curvature of the tyre, and control means for selectively moving supporting means 44 for the mounting means in a direction so that the buffing element is moved forwardly and reversely substantially radially of the tyre, the control means including means operable after a predetermined movement of the element to reverse the direction of movement. The tyre is supported on a table 21 secured to a shaft 18 and is held in position by discs 14, 15, the upper disc being movable downwardly by a piston-and-cylinder device 24 to seal the rims of the tyre so that pneumatic pressure supplied through a bore in the shaft inflates the tyre, the upper disc being movable against a spring in a housing 22. The tyre is rotated by engagement of a clutch 29 which is operable by a piston-and-cylinder device 33 to connect the shaft 18 to a motor M-1. The buffing element consists of an abrasive band 36 carried by rollers 38, 40 on an arm 39 which is rotatable in a sleeve 42 carried by a table 44 on which is a motor M-2 connected by bolts 49 to the pulley 38. The table can be moved so that the band moves radially of the tyre by a screw-andnut mechanism 55, 56 connected by a chain 57 to a motor M-4. The tyre is polished at a point diametrically opposite the band by a wheel 64 carried by a spindle 65 driven by a motor M-3. The wheel can be adjusted radially of the tyre by a screw-and-nut mechanism 67, 73 driven by gearing 74 connected to a handwheel 75 and the polishing unit as a whole pivoted about a shaft in bearings 72, by a piston-and-cylinder device 62 to bring the wheel into contact with the tyre. In operation, the operator actuates a start button to energise the motors M-1, M-3 driving the band 36 and wheel 64, respectively. Motor M-1, however, is disengaged from the shaft 18 by the clutch 29. A tyre is placed on the table 21 and the device 24 operated to move the disc 14 into sealing engagement with the tyre which is then inflated. Operation of the device 33 by a footcontrolled valve 71 engages the clutch to rotate the tyre. The band 36 is then moved to a position adjacent the bead 37 on the tyre by operating the motor M-4 to move the table 44 in one direction or the other. A handle 59 on the arm 39 enables the operator to bring the band into engagement with the tyre, the pivoting of the table 44 operating a switch to energise the motor M-4 so that the band moves radially-inwardly of the tyre, the operator rotating the rod 39 so that the band conforms to the curvation of the tyre. If, during the movement inwardly, the operator raises the arm 39, the motor M-4 is reversed to move the table back to its original position. When the band has moved sufficiently inwards and the arm 39 raised, a limit switch is operated to reverse the motor M-4. At, or before, the operation of the limit switch, a pin 81 actuates a switch LS-3 controlling the piston-and-cylinder device 62 which swings the wheel 64 into engagement with the tyre for a length of time determined by a times and relay, the device 62 then being actuated to lift the wheel from the tyre.