| 摘要 |
<p>1,155,188. Roughening &c. tyres. H. TIES. 26 Sept., 1966 [25 Sept., 1965], No. 42926/66. Heading B4B. In a machine for rasping and roughening a worn pneumatic tyre 2 for retreading in which the tyre is clamped in the machine frame 1 between two rim plates 4, 5 axially movable relative to each other and rotatable about a horizontal axis, means are provided whereby the axial movements of the rim plates are equal and opposite. The rim plates are carried by stub axles 6, 7 which are axially shiftably supported in uprights 1a, 1b of the frame 1 by means of nuts 32 driven by chains 33. The movement of the rim plates is controlled by limit switches adjustable on a scale 34. The opening distance between the rim plates to an amount just allowing insertion of the tyre is controlled by limit switch 35. Starting from this position, the drive for adjusting the rim plates is switched on by a pedal-operated switch which when a filling mouth width is reached in which the tyre beads 2a, Fig. 2, sealingly engage the rim flanges 4a, 5a, is switched off by limit switch 37. Compressed air is fed into the tyre, under control of the switch 37, to a predetermined pre-fill pressure. The rim plates are then moved apart to the operating mouth width as determined by limit switch 38 or the tyre is centred relative to the axis of shaft 3. For this purpose, the rim plates 4b, 5b, Fig. 2, are made axially longer than the width of the tyre feet 2b. When the rim plates are moved apart beyond the operating mouth width, the tyre is spread by the pre-fill pressure which causes tilting of the tyre feet about an axis extending approximately midway of the tyre feet. If the rim diameter of the tyre is greater than the nominal rim diameter, the tyre bead lifts itself off the rim while the inner edge 2c approaches the rim. In this way, the inner edge tightly seats on the rim plates 4b, 5b and the tyre is centred. After this, the rim plates may, if desired, be moved towards each other again and the tyre processing started. Simultaneously, the supply of compressed air is automatically switched on to establish the operating pressure. The mouth width of the rim plates, which is greater than the operating mouth width and serves to centre the tyre, is determined either by limit switch 35 or by an additional limit switch (38a), Fig. 3 (not shown). The tyre is rotated by means of a motor-driven knurled roller 8.</p> |
