| 摘要 |
1,210,293. Filter clogging indicator. PRECISION MECANIQUE LABINAL. 17 June, 1968 [20 June, 1967], No. 28804/68. Heading B1D. The pressure P o upstream and pressure P downstream of a filter, in an engine lubrication circuit, are applied to respective chambers 7 and 9 where they urge diaphragms 4, 5 in opposite directions, causing contact 22 to engage contact 17 when the pressure difference rises sufficiently. The downstream pressure is also applied to diaphragm 6, bearing against spring 27, which closes contact 23 on to contact 17 when the downstream pressure falls sufficiently. Springs 20, 21 carrying contacts 22, 23 are located in chambers 8, 10 which are open to the atmosphere. Closing of either pair of contacts illuminates a signal lamp, possibly to different degrees of illumination. The whole unit, comprising chambers 7-10 and contacts 17-23 is screwed into a filter housing 3. Alternatively (Fig. 2, not shown) the chambers and electrical contacts are made as separate units which demountably fit together. |
