| 摘要 |
<p>993,800. Seals; pneumatic springs. H. P. DOETSCH. May 14, 1962 [May 19, 1961], No. 18513/62. Headings F2B and F2S. A high-pressure seal in the cylinder 11 of a gas spring, Fig. 5, comprises a radially-stressed, highly resilient, abrasion-resistant and flat sealing ring 1 which is arranged with its inner and outer periphery in sealing engagement with the piston-rod 7 and cylinder 11 respectively and in its flat operative condition is urged by the gas pressure against an abutment 9 held against axial movement away from the ring; in its initial unstressed condition, Fig. 1, the ring has its central hole of frusto-conical shape with the larger diameter corresponding to that of the piston-rod and the outer periphery may be of corresponding frusto-conical shape so that in operation the ring is flattened and the internal forces generated in it compress the periphery of the hole at one side against the piston-rod and the outer periphery of the ring at the other side against the cylinder. The ring is fitted on the piston-rod between the abutment 9 and a guidering 12 loosely slidable in the cylinder, the abutment being in the form of a washer as shown or an end flange on the cylinder. Filling of the cylinder with gas is effected through the annular passages initially separating the parts 11, 9, 1, 12 while the piston-rod is brought to bear on a stop 13; on removal of the stop the gas pressure urges the piston-rod inwardly and the seal to its flattened sealing condition. The ring may be formed of a plastic such as ethylene glycol-adipic acid polyesters, if desired of oil-absorbing type or combined with high-alloyed nickel chromium steels; the ring may also be coated with finelyground chromium. The ring may be stamped from the material while the latter is supported on a soft backing penetratable by the tool and the progress of the tool through the material may be briefly interrupted before it completely penetrates the material so as to produce a hole with the cross-section shown in Fig. 7.</p> |
