| 摘要 |
<p>1,135,037. Rotary vacuum-pumps. LEYBOLD HOLDING A. G. Dec. 10, 1965 [Dec. 12, 1964], No.52627/65. Heading F1F. [Also in Division B1] Air discharged by a vacuum pump passes by exhaust branch 2 to a glass wool filter 32, from the downstream side of which coalesced oil is returned to the pump. In Fig. 2 the collected oil is returned by float-operated valve 4 and pipe 5 to a nozzle 8 through which the pump exhaust valve discharges into the pump casing, nozzle 8 providing a suction to assist gravity flow of the returning oil. In Fig. 1 (not shown), valve 4 opens into the suction side 6 of the pump. In Fig. 3 (not shown) a breather valve (9) replaces valve 4 and intermittently discharges oil and air into the space upstream of the pump exhaust valve when the pressure therein falls below that downstream of the filter. Or gravity alone may return the oil.</p> |
