| 摘要 |
<p>The ribs enter into and are held by the stem constrictions. At least one slot is provided in the cap, so that it can be put on the bulb neck and fastened on it. The bulb is made of a material with sufficient elasticity and low hysteresis. Further ribs are provided on each side of each slot, and the bulb neck has a number of recesses (13) at least equal to that of slots (8), which interact with the ribs when the transversal ribs (10,11) are inserted in the constrictions (2,3) in the bulb neck (1). Ribs are clamped in the recesses (13) so that they counteract any widening of the cap (5).</p> |
