| 摘要 |
<p>A piston for a pressure-dispensing container such as a cartridge for an extrusion gun has its closure panel formed of a central portion (34) arranged to receive the applied extrusion forces, and an annular and frustoconical outer portion (40) arranged to transmit the extrusion forces to the piston skirt (30) with an outwardly directed component by which the skirt is radially expanded to make firm sealing engagement with the container bore. The central portion is rigid so as to withstand the extrusion forces without any substantial distortion; the outer portion acts as a substantially rigid annular strut, notches (44) localising any bending movements to the junctions of the outer portion with the central portion and with the skirt.</p> |
