| 摘要 |
<p>1479946 Pressure gauges SOFILTRA SOC INDUSTRIELLE DE FILTRATION 3 Oct 1974 [3 Oct 1973] 43028/74 Heading G1L [Also in Division H1] A device for indicating blockage of a filter, e.g. of an I.C. engine air intake, and of the kind having a part-transparent housing and an indicator attached to a diaphragm, the indicator being moved into view through the transparent portion by movement of the diaphragm in response to an excessive drop in pressure at the filter outlet, includes switch means operated by the diaphragm to give a remote indication of blockage. Locking means prevents return of the diaphragm and thus switching off until the device is reset. The diaphragm 5 in the arrangement shown, divides the housing into compartments 6a, 6b, the former being connected to the filter outlet 10 and the latter to atmosphere. An indicator 15 is attached to the diaphragm and, when a pressure drop expands the bellows of the latter, is visible through the transparent wall 2a to denote blockage. At the same time contacts 20, 21 of a switch are closed to give the remote signal. A hairpin element 31 is drawn by the diaphragm movement through an aperture 4 in a fixed partition 3 until rachet teeth 34, 35 on the arms 32a, 33a engage beneath the partition, locking the indicator and the switch in the blockage signalling position. The diaphragm is released by pressing down a member 38 having an aperture 40 which fits over the upper ends of the arms to draw them together to free the teeth 34, 35. A spring 16 then returns the diaphragm, opens the switch and causes the indicator to enter the opaque part of the housing.</p> |
