GB855956A - Improvements in or relating to valves for pumps - Google Patents

Abstract

855,956. Valves. MISSION MANUFACTURING CO. Jan. 7, 1957, No. 611/57. Class 135. A valve for pumps has a valve member C with a sealing surface 33 co-operable with a valve seat 15 on a valve seat member A and also has a further sealing surface 35 which engages with the bore 24 of an upper flexible portion of a sealing ring B to form an initial seal which prior to engagement of the surface 33 and the valve seat 15, the bore 24 extending above the valve seat at an angle to the axis of reciprocation of the valve member which is less than the angle defined by the valve seat and the axis of reciprocation. The seat member A is mounted in a bore 10 in the pump body P and a groove with an 0-ring 12 is provided in the seat member or in the pump body or is omitted from either. The sealing ring B which may be of rubber, plastic or the like is mounted in a recess 20 at the top of the seat member and retained in the recess by a band 27 of metal, plastic or other material. The sealing ring B is additionally secured by a projection 29 engaging a groove 28 in the ring. Alternatively the groove may be in the seat member. The valve member C has a body portion 30 with axial stems 31, 32. The lower stem 32 is guided in a bushing 18 supported by one or more webs 17. The sealing surface 33 and the valve seat 15 have the same inclination to the vertical axis of the valve. The surfaces 24, 35 are more steeply inclined to the horizontal, the surface or bore 24 being somewhat steeper than the surface 35 so that as the surfaces engage initially there is slight radial expansion of the upper end of the ring B as relative sliding movement takes place. The surface 35 is at 15 degrees to the vertical whereas the surface 24 is at 10 degrees. In a modification the surfaces 24 and 35 are both parallel to the vertical axis of the valve member and in a further modification, the bore 24 is parallel to the valve axis and the surface 35 is inclined to the valve axis. In the last case a certain amount of radial distension of the upper part of the sealing ring occurs. In another form, the body portion 30 of the valve member is thicker and the surface 33 extends to the stem 32 and contacts the upper edges of the wings 17 which in this case slope upwardly and outwardly to the lower edge 15b of the valve seat. Another form has a disc-like valve member with horizontal and vertical sealing surfaces these co-operating with corresponding horizontal and vertical surfaces on the valve seat member and sealing ring respectively. Another form, Fig. 7, with a disc-like valve member 530 has a vertical sealing surface 535 co-operating with a vertical bore 524 in the sealing ring B, an inclined sealing surface 533 adapted to engage a valve seat 15, and a horizontal surface 534 engageable with the tops 517a of ribs 517. In Fig. 8, the lower valve stem 632 is welded or otherwise secured to a sleeve 618 connected by webs 617 to arcuate guide shoes 50 sliding in a bore 616. The longitudinal wall of the recess 620 accommodating the sealing ring B and the corresponding internal surface of this ring are flared outwardly and downwardly at an inclination equal but opposite to that of the bore 24. This arrangement results in equal outward displacement of the edges 36 and 15a, Fig. 1, under wear so that full seating of the valve achieved even after wear has taken place.