Abstract:
The invention contemplates a combined closure spring and upstop having particular application to check valves having multiple valve members. The invention is illustrated by one embodiment involving two valve members hinged on a single axis oriented diametrically of the valve-flow passage, and by another embodiment involving more than two valve members hinged on separate axes oriented tangentially of the valve-flow passage.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to check-valves of the variety in which multiple like valve members (petals) are hinged for independent coaction with the respective valve-seat openings in a seating plane; in the case of a double-petal valve, said openings are defined by a seat post which extends diametrically across the bore of the valve body. Check valves of this character are illustratively described in U.S. Pat. Nos. 2,877,792 (Tybus), No. 3,538,946 (Hilsheimer), No. 3,678,958 (Satterwhite, et al.), and No. 4,079,751 (Partridge, et al.). 
     In the foregoing patents and in all other similar check valves known to me, the valve body includes or carries a fixed stop against which the valve members abut to determine their full-open position. For certain applications, the provision of such a stop entails complexity of body construction and mechanical shock associated with attainment of the full-open position of the valve. Such shock is aggravated under conditions of frequent and intermittent demand for full-flow use of the valve. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved check-valve construction of the character indicated, featuring simplicity of construction and maintenance, and improved performance, as compared to existing constructions. 
     A specific object is to achieve the above object with a construction having inherently improved flowaccommodating properties, for a valve of given size. 
     Another specific object is to provide an improved up-stop function in a valve of the character indicated, without reliance upon special formation of or assembly to the body of the valve. 
     A further specific object is to achieve the above objects with the additional provision of resiliently snubbed determination of the full-open condition of the valve. 
     In a double-petal application, the invention achieves the foregoing and other objects and features by providing spring means on at least one of the valve members in such position as to resiliently engage the other valve member when in full-open position, thus cushioning the achievement of full-open position of both valve members, without reliance on valve body structure to provide any up-stop function. Preferably, the spring means for achieving this function is an integral formation on the same spring means as is used to normally urge the valve members in the valve-closing direction. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the invention will be described in connection with the accompanying drawings, in which: 
     FIG. 1 is a view in elevation of a check valve of the invention, as viewed from the downstream end; 
     FIG. 2 is a longitudinal sectional view, taken at 2--2 in FIG. 1, showing one half of the valve closed, and the other half in phantom for its open position; 
     FIG. 3 is a view in elevation of a spring component of the structure of FIG. 1; 
     FIG. 4 is a fragmentary longitudinal sectional view of another type of check valve incorporating the spring feature of the invention; and 
     FIG. 5 is a sectional view taken at 5--5 in FIG. 4. 
    
    
     In FIGS. 1 to 3, the invention is shown in application to a check valve comprising a body 10 having a cylindrical annular shell 11 with a thin circumferential mounting flange 12 and with a cylindrical bore which is divided into two like generally semi-cylindrical seat openings or ports A-B, by means of a seat post 13 which extends diametrically across the bore and is preferably integral with the shell 11. Also integral with shell 11 are diametrically opposed bearing mounts 14-15, for location of the diametrically opposite ends of a hinge pintel 16, on an alignment parallel to seat post 13 and at a downstream offset from the valve-seating plane, the latter being established by the otherwise flat downstream end of body shell 11. Two like generally semi-circular valve members 17-18 are connected (via their hinge arms 19) by pintel 16 to the body shell, for independent articulation about the hinge axis; and in the closed or valve-checking position, valve members 17-18 will be understood to peripherally continuously lap all seating surfaces of shell 11 and seat post 13 in the seating plane. 
     In the form of FIGS. 1 to 3, separate spring means 20-20&#39; are employed to normally urge the respective valve members 17-18 in the valve-closing direction. These springs are duplicates of each other, so that the spring 20 of FIG. 3 is illustrative of either one of them, primed notation being used for the corresponding parts of spring 20&#39;. At one end of the coil of spring 20, a first arm 21 extends into a central local bore 22 in seat post 13, for frame-referencing purposes, the pintel 16 extending through the coil of spring 20; and a second arm 23 at the other end of the coil extends along the back of valve member 17 to urge the same in the valve-closing direction. A similar action applies for spring 21, frame-referenced at 22 and urging valve member 18 in the valve-closing direction, it being noted that the coiled parts of springs 20-21 are retained via bore 22 at diametrically opposite symmetrical locations on pintel 16. 
     In accordance with the invention, further spring means is provided on the back or downstream side of at least one of the valve members 17-18 in such position and orientation as to resiliently engage the back of the other valve member at the full-open position of these members. Such further spring means, in FIGS. 1 to 3, takes the form of a snubber formation 24 in the shape of an integral hook or loop extending at an angular offset δ 1  with respect to the arm 23 of spring 20, the offset δ 1  in FIG. 3 being shown between a first plane 25 (representing constant contact with the back of valve member 17) and a second plane 26 (representing intermittent abutment with the back of valve member 18), to depict the full-open relation of valve members, as determined by spring 20. Preferably, the radius R 1  of curvature at juncture of hook 24 to arm 23 matches the radius R 2  of curvature of hook 24, and the complement δ 2  of the inclination of hook 24 to the arm is δ 1 , whereby the maximum radius R 3  of arm (23) contact with valve member 17 substantially equals the radius R 4  of hook (24) contact with valve member 18. This being the case for spring 20 and its hook formation 24, it is also the diametrically opposite case for spring 20&#39; and its hook formation 24&#39;, thus assuring symmetry of snubbed valve-member up-stop action upon achievement of the full-open condition of the valve. 
     The embodiment of FIGS. 4 and 5 represents application of the up-stop spring feature of the invention to a different form of multi-petal check valve, which happens to employ plural angularly sequential valve members or petals 30 which are of sector shape and which are tangentially hinged to surrounding frame structure via radially outward hinge arms 31. To accommodate the full-open swing of petals 30 plus hinge brackets 32 for arms 31 and their connecting pintel 33, an inlet ring 34 with integral seat-post formations 35 has a radially outward flange 36 which is lapped by the adjacent radially inward flange 37 of an outlet ring 38, the two rings 34-38 being secured at their flanges by bolts 39 which also serve to mount the brackets 32 to flange 37. A first spring 40 has frame reference at an anchoring aperture 41 in the base of bracket 32, thus also axially locating spring 40 and assuring the central action of the petal-operating other end arm of spring 40; as in the case of FIGS. 1 to 3, the petal-engaging end arm of spring 40 has a hook-shaped offset 42, poised for up-stop action upon the inner wall surface of the outlet ring 38. It will be understood that, for many applications the single spring 40 will suffice, in that up-stop action and petalseating action are generally central and symmetrical with respect to the spaced points of hinge support. However, for total symmetry, I show an additional spring 40&#39; which is the mirror image of spring 40 and which is carried on the remaining span of pintel 33; spring 40&#39; is frame-referenced at one end in bracket aperture 41&#39; and has an up-stop hook formation 42&#39; at its centrally located other end, in mirror-image relation to spring 40 about the center of symmetry of petal 30. 
     The described embodiments will be seen to meet all stated objects with structure of elemental simplicity and lending itself to application in either a diametrically or a tangentially oriented body suspension of the hinge. In all cases, the full-open position of valve members is snubbed and effectively stopped, snub forces being sustained by each valve member with mirror-image symmetry, about the central axis of symmetry of the valve member. 
     While the invention has been described in detail for the preferred forms shown, it will be understood that modifications may be made without departing from the claimed scope of the invention. For example, by eliminating the mounting flange 12, to leave body shell 11 with a suitably grooved outer cylindrical profile, the complete check valve of the FIG. 1 variety may be installed and retained in the bore of a pipe, conduit or other suitably grooved fitting, as in the manner disclosed in detail in copending application Ser. No. 27,846, filed Apr. 6, 1979.