| 摘要 |
<p>783,266. Pipe couplings. WURZBURGER, P. D. Nov. 7, 1955 [Nov. 8, 1954], No. 31797/55. Class 99(1). In a pipe coupling comprising two coupling members B, C provided with valves 32, 72 which are closed whilst the members are uncoupled but are both opened successively by coupling interengagement between the members and to provide a passage for fluid flow through the members, when coupling pipes conveying fluid under pressure, the fluid pressure released by the valve first opened helps to complete opening of the passage through the members. The pipe couplings described are identical with those described in Specification 783,265. In the coupling part B, the 0-ring 50 effects a seal between the valve body 32 and the surface 17 of the stem 16, i.e. at a diameter a, Fig. 11, whilst the seal between the valve body and the seat 25 thereof is effective at an approximate diameter b, the difference in area between the circles of diameters a and b representing the effective area over which the internal fluid pressure acts on the valve to hold the valve on the seat 25. The effective area over which internal fluid pressure acts on the valve 72 is represented by the difference in area of a circle of diameter e, Fig. 11, at which the seal is effected between the valve seat 87 and the tapered surface 85 at the forward end of the valve, and a circle of diameter f being the diameter of the external surface 74 of the valve with which the O-ring 77 makes a circular seal. The diameters of the seals associated with the valves 32, 72 may be modified so that biasing and seating forces acting on the valves are supplied wholly by the springs 38, 80. On coupling the parts B, C, and in the initial position, the end face 27 of the member 8 of the part B engages the radial shoulder 90 of the valve 72 in the part C, the 0-ring 59 in the head 67 of the stem 66 making fluid-tight contact with the inner surface 23 of the valve 32 in the part B, before the member 8 pushes the valve 72 off the seat 87. As the parts B, C are pushed further towards one another, Fig. 12, the member 8 displaces the valve 72 from sealing engagement with the seat 87 and fluid pressure from the passages 62, 65 of the part C flows around the valve to act against a frontal area thereof of diameter d so that the force applied during movements of the coupling parts from the stage shown in Fig. 11 to the second stage, Fig. 12, is less than the force required for initial movement of the valve ; fluid pressure then acts on the valve 32 over an area equal to the difference in area of the circles b, c thereby reducing the force necessary to push back the valve. As the parts B, C are pushed even further together the head 67 first engages, and then, aided by the fluid pressure, pushes the valve 32 away from the seat 25 to place the passages of the parts in communication with one another, the force, ignoring the effects of the valve springs 38, 80, necessary to effect displacement of the valve being equal to that exerted by the fluid pressure over an area equal to the difference in area between circles of diameters a and c respectively. Fig. 13 shows the final stage of coupling the parts B, C, wherein both valves 32, 72 are opened fully. In modifications, one or both of the 0-rings 30 and 77 are carried in grooves formed in the valve 72, the O-ring 50 is located in a groove provided in the stem 16, and the 0-ring 59 lies within a groove in the wall 23 of the valve 32.</p> |
