GB589458A - Filters - Google Patents

Abstract

589,458. Filters. VOKES, C. G. March 16, 1945, No. 6693. [Class 46] [Also in Group XXVIII] A casing enclosing a filter unit is provided at one end with an inlet for fluid communicating with the outside of the unit and surrounding an outlet communicating with the inside of the unit, an annular bye-pass valve being provided between the inlet and outlet and being adapted to open on excessive resistance to flow of the fluid. As shown in Fig. 1, a header 2 is connected by a bolt 14 to a casing 1 enclosing a deeply-pleated filter screen 7. The screen is secured on a perforated cylinder 8 between end caps 9, 10, the upper cap being secured to a tube 13 slidable on the bolt 14. A flexible fabric sleeve 11 attached to the cap 10 surrounds a compression spring 12, which presses the screen upwardly so that the cap 9 engages an annular seating 26. When the pressure outside the screen is sufficiently high the screen moves down allowing the fluid to flow directly from the inlet 5 across to the outlet 3. In a modification shown in Fig. 2, the filter unit is assembled by means of a rod 22 and nut 23. The end cap 9 has a neck 24 secured to the rod 22 by a pin 27, the neck being provided with a flange 25 and jointing 26 which are held against the header 2 by a spring 33. An annular valve 28 is pressed against the cap 9 by a spring 30 which is not so strong as the spring 33. When the external pressure is sufficiently great the valve is moved from its seat allowing fluid to pass from inlet 5 through apertures 32 into the central outlet 3. Specification 589,457 is referred to in the Provisional Specification.