| 摘要 |
<p>Subtread reinforcement of tyres has heavy section tread ribs in a broken vee or fishtail pattern where that part of the sub tread reinforcement ply which would have a cord axis closely aligned with the external ribs is covered with an ancillary ply laid with a cord axis >=30, pref. 65-90 degrees off the rib axis. Used esp. for sub tread reinforcement of heavy duty, off-the-road tyres, viz for the driving wheels of agricultural tractors, earth movers, etc. Structure with the surface ply cords offset from the axes of the adjacent tread ribs have less tendancy to lose local material by entrainment with material flowing into the rib cavity during moulding, hence are less prone to develop voids or trap air which could promote delamination under the centre of the rib in service.</p> |
