| 摘要 |
In a fluid seal between a pair of confronting, generally parallel surfaces, one of said surfaces having mounted thereon a sealing device having a pair of lip members adapted for contact with the other of said confronting surfaces and defining therebetween a fluid passage subject to subatmospheric pressures when said sealing device is operative, the improvement comprising means disposed in one or the other of said confronting surfaces for venting said fluid passage to atmosphere prior to effecting separation of said confronting surfaces. |
