| 摘要 |
1,015,774. Liquid filters in parallel ; bypassing. ROSAEN FILTER CO. Feb. 26, 1963 [April 9, 1962], No. 7762/63. Heading BID. In a filter device having a primary and a secondary filter element, a valve is provided which variably increases the fluid flowing from the secondary filter element to an outlet as the primary filter element becomes clogged. As shown, a cylindrical housing member 10 has a cap member 11 mounted at one end, with a cylindrical boss 15 and at the other end an outlet 13 whilst the inlet is at 14. Mounted in the boss 15 is a rod 17 which carries a valve member 21 and an annular spacer 24 with magnets 23 at its other end. The primary and the secondary annular filters 37 and 38 respectively are mounted on either side of a ring member 36 which has a flange portion 39 and edge 40 whilst the other end of filter 37 is attached to a carrier 26 having a ring seal 28 to prevent fluid leakage. Filter 38 is attached to an annular member 32 having an O-ring seal 35 and being mounted on a surface 15C; the carrier 26, ring member 36 and member 32 are joined together and held in alignment by screws 33. In operation fluid enters at 14 and passes through filter 37 and out at 13 whilst the valve member 21 and flange 39 prevent fluid passing through coarse filter 38. As filter 37 becomes clogged, the pressure differential acting on flange 39 moves the filter carriage along against the action of a spring 30 and allows fluid to flow through filter 38. As the filter 38 clogs and the pressure rises further, the filter carriage moves further along until the annular member 32 is in a position to allow fluid to pass around guides 15A and thus by-pass both the filters. A device 45 for indicating the position of the carriage and the necessity for cleaning the filters may also be provided, which device is connected by mechanical links to the carriage at the annular member 32. |
