| 摘要 |
1,119,032. Oil filter; magnetic filters. H. TEVES, E. A. TEVES and M. TAUSEND [trading as ALFRED TEVES MASCHINENUND ARMATURENFABRIK K.G.]. 10 Feb., 1966 [22 May, 1965], No. 5882/66. Headings B1D and B2J. In an oil filter for a hydraulic system comprising a pleated paper filter element 3 and magnet 4 in. series, a by-pass valve 7, 11 is combined with an electrical contact device 10, 15 whereby an external visible or audible warning is given at a lower pressure differential than that which opens the valve. As shown. annular piston 11 is linked to contact pin 9 and loaded by spring 12. Increasing differential pressure lifts pin 9 and piston 11 together. until contact plate 10 connects contacts 15 and prevents further rise of pin 9, after which piston 11 slides up pin 9 to open the by-pass passage 7, 17 between inlet 5 and outlet 6. The space above plate 10 is connected to atmosphere by vent 14 so that the warning is also given in response to an excessive absolute pressure in the filter. The alarm circuit may incorporate a bimetallic switch, to prevent the alarm responding to an excess pressure caused by high viscosity in oil at low temperature. |
