| 摘要 |
The teat cover (1) described has a cross section which changes gradually and continuously from circular near the top (2) to non-circular near the bottom (3). The wall thickness of the teat cover (1) near the bottom (3) is smaller along the minor axis and greater along the major axis than near the top (2). When the outside of the teat cover (1) is acted on by atmospheric pressure, the bottom part (3) of the teat cover (1) collapses along its minor axis since the external pressure acting in this direction acts on a larger surface. The smaller wall thickness along this axis facilitates the collapse. The reduction in cross-sectional area due to the smaller wall thickness is compensated for by the larger wall thickness along the major axis, thus ensuring that the drop in initial tension due to plastic flow in the teat-cover material occurs no earlier than with teat covers with walls of constant thickness. |
