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Publication numberUS2675823 A
Publication typeGrant
Publication dateApr 20, 1954
Filing dateSep 7, 1949
Priority dateSep 7, 1949
Publication numberUS 2675823 A, US 2675823A, US-A-2675823, US2675823 A, US2675823A
InventorsLangdon Jesse D
Original AssigneeLangdon Jesse D
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Backflow preventer
US 2675823 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

April 20, 1954 J. LANGDON BACKFLOW PREVENTER Filed Sept. 7, 1949 Inventor fia a Patented Apr. 20, 1954 UNITED STATES PATENT OFFICE BACKFLOW PREVENTER Jesse D. Langdon, Long Beach, Calif.

Application September 7, 1949, Serial No. 114,418

9 Claims.

This application is a continuation in part of Ser. No. 735,733, March 28, 1949, now abandoned.

The invention relates to check valves particularly for use with devices to prevent a backfiow of contaminated fluid into the outlet of a device having its inlet end connected to a source of fluid supply.

The primary purpose of the invention is to provide a double acting check valve mechanism for closing air vents in a casing having inlet and outlet ends, and to prevent backflow thru the double valve when a greater pressure exists at the outlet end.

Another object is to provide a check valve having more than one check valved opening cooperably combined in a single unit.

Another object is to provide a check valve unit having multiple chamber means found within a flexible wall surrounding the chamber means whereby a greater initial pressure can be held in one chamber than in another chambered portion of the device.

Another object is to devise means for changing the differential of pressure between the multiple chambers of the instant type of device.

A'further object is to maintain a greater pres" sure in that portion of a flexible tubular check valve member that overlies the inside of an adjacent perforated casing wall area to thereby minimize aspiratory noise therethru caused by the entrainment of air by a stream of water passing thru the check valve and the casing.

Other and further objects and purposes will appear during the progress of the specification.

Only one form of reduction to practice is illustrated by the drawing and it is specifically understood that reduction to practice shown may be changed within that anticipated by the specification and Within the scope of the claims.

The figure of the drawing illustrates in vertical median section, a valve organization as embodied in the invention.

The drawing shows a valve member I made of distortable material capable of returning to normal shape and having an inlet end 2 and an outlet end 3 with a preferably bell shaped valve member i; attached to a cage intervening between the inlet 2 and outlet 3 and formed by barred spider washer 5, secured in a groove G, provided circumierentially internally of the flange IF which is extended radially outward of the inlet end 2 of the member I, the latter inserted into the casing I and resting on the internal annular shoulder portion 6 of easing I which is provided with thread means IT for pressure sealing and coupling the device to a'source of pressure fluid supply.

The casing I is provided with vents V, thru the wall thereof. The casing I being coupled to a source of pressure fluid supply and liquid under pressure flowing thru the valve member i, the bell washer l inserted into and encased by the flexible sleeve portion of member I, surrounding bell 4 forms a chamber 4C which causes the member I to be bulged radially outward under the influence of internal pressure as shown by dotted lines B, closing the vents V. The flowing liquid forms a circumferential slit opening BS between the lower peripheral extremity of bell 4. The inside wall of member I permits the passage of pressure fluid thru slit BS into another chamber lC defined by the member I which has the transverse diaphragm like outlet end 3 normally closed provided with a forwardly projecting lipped portion L which is slit at AS; the lipped portion L forming the opposite sides bordering the slit AS and normally touching one another to close the slit AS.

It will be noted that a comparatively large annular clearance space is provided between the wall of member I and wall of casing I which is closed by bulge B of sleeve I due to internal pres sure. The large clearance space is made practical without danger of leakage of internal pressure fluid thru the vents, due to internal pressure within member I being enhanced by the double bafile effect of bell 4 and closed end 3 of member I causing the same to expand against wall of casing 1 as at B.

The member I when in operation will normally retain liquid in the chambers both above and below the bell 4 as atmospheric pressure or other pressure exerted against the external closed portion of member I will close slit AS and compress Itahe Zvall of member I against the periphery of ell The drawing shows bell 3 as forming a baflle with an imperforate wall portion presenting a seating face interceding intermediate of the cage 5 and outlet end 3, of sleeve member I. The bell 4 is held in juxtaposition with the barred spider forming cage 5 and concentric to the flange IF and the wall of member I. The lower edge of bell 4 is concomitant with the surrounding wall of sleeve member I made of deformable material. When external pressure is exerted against the exterior of member I the wall thereof is collapsed around bafiie 4 and the lip bordered slit end 3-L-AS is urged shut until such time as external pressure becomes great enough to overcome the resistance or" the lipped end L-AS of member I reversing the same thru the slit end 3 and into the chamber IC of member I. The forward face of bell d intercedes between the openings of cage and slit AS. The wall of member I will deform under external pressure, collapse and cause slit AS to be opened in a reverse direction. It is obvious that without bafile 4 the openings of cage 5 between the bars thereof would permit the lips of member i to be urged therethru by excessive external pressure and thereby permit backflow of pressure fluid thru sleeve member I.

Unless atmospheric or other pressure enters above inlet end 2 liquid in the chambers of member i can not be expelled. Further, if the assembly as shown were disconnected, being full of liquid, the normal tension of wall of member I against the periphery of the bell would hold a body of liquid in the chamber above bell 4 while the tension of lipped portion 3 of member I closing the slit AS would retain liquid in the lower chamber IC.

A bell-shaped washer '9 made of metal or other suitable rigid material retains the bell 4 in as sembled relationshipwith spider 5 by means of a rivet R or other suitable means.

When a'subatmospheric pressure exists at the inlet endi in the chamber 20 the member 5 is collapsed by atmospheric pressure against the periphery of bell li forming a check valve by the contact or bell member l with the wall of member 2 While slit AS is likewise closed by a subatrnos pheric pressure existing in chamber 30.

Having described the invention and the operation thereof, the-following claims are made:

1. A backflow preventer comprising a tubular sleeveinember having inlet and outlet ends and being made of deformable material capable resuming shape afterbeing deformed, the sleeve being providedwith-pressure sealing means for making a connection with a source of pressure fluid supply at the inlet end and having an imperforate sidewall portion between the two ends, a normally closed lip bordered slit outlet end forming a check valve, a flexible bell shaped member secured in concentric relationship to the inlet end and within the sleeve, the periphery of the bell projecting toward the sleeve wall and constituting a second check valve in combination with the surrounding wall of said sleeve whereby subatmospheric pressure within the inlet end above the bell will permit atmospheric'pressure to urge the sleeve wall inwardly against the periphery of the bell preventing ingress of pressure fluid toward the inlet end past the periphery of the bell, the normally closed lip bordered slit end of the sleeve being further compressed together by external pressure against the lipped end and providing addtional check valve means at the outlet end of said sleeve, resisting backflow of pressure thru the sleeve.

2. A deformable sleeve as defined by claim 1 inserted into a tubular casing having an inlet end and an outlet end, with vent means thru the casing wall between two ends, the pressure sealing means including juxtapositioned concomitant inlet ends of the casing and sleeve, the imperforate side wall of said sleeve overlying said vent means, internal pressure expanding said imperforate side wall against the casing wall closing said vents against egress'of pressure fluid, said bell washer forming a baflie to impede flow of pressure fluid thruthe sleeve and expand same against the casing wall, the normally closed lip bordered slit end forming a restricted outlet adapted to resist flow of pressure fluid thru said sleeve to further enhance the effects of internal pressure causing the expansion of said sleeve above said baffle against the casing wall to close said vents.

3. An article of manufacture comprising a sleeve member made of deformable material having a flanged inlet end, a normally closed slit restricted outlet end and an imperforate tubular wall between the ends, a caged support juxtapositioned across the inlet end and attached to a bafiie disposed concentrically within the imperiorate wall of the member surrounding said bafile, same dividing the inside of said sleeve member into two chambers and preventing the slit outlet end of the deformable member from being reversed thru said caged support by external pressure.

i. A device as defined by claim 3 wherein the concentrically disposed baiile is bell shaped and the peripheral edge of the bell juxtapositioned, extended toward, and concentric with the wall of the deformable sleeve member.

5. An article of manufacture as defined by claim 3 wherein the flange of the sleeve valve member forms a gasket extended radially outwardly of the inlet and adapted to form pressure sealing means for insertion between opposing faces of coupling means adapted to retain said sleeve member in a pressure sealed position interrupting between a source of fluid supply and the outlet end of a fluid conduit.

6. A backfiow preventer check valve unit, in cluding a tubular casing having inlet and outlet ends and being vented between the two ends, combined with a sleeve member having a flanged end concomitant with the inlet and being made of shape resuming deformable material, the inlet end of said casing-extended radially outwardly forming an annular shoulder supporting the flanged end of the sleeve the opposite end of the sleeve member provided with'a normally closed lip-bordered slit outlet passageway for pressure fluid, a cage having a rim juxtapositioned concomitant with the flange, a bafile depending from said rim and extending transversely of said sleeve intermediate of the two ends, said baille presenting a seating face toward the closed end of said sleeve member, said sleeve member being urge, toward said seating face by external pressure at such times as pressure internally or" said'sleeve is less than externalpressure thereagainst, the slit end of said sleeve member forming one check valve subject to being urged shut under one condition of external; pressure, a second check valve formed by the conjunction of the sleeve wall with said bafilewhereby in'the event of the slit end of the sleeve being inverted by excessive external pressure, the wall and the slit end of said sleeve urged against said baifie will'prevent reversal of the outlet end of said sleeve thrusaid and baokflow ofpressurefiuid thru the inlet end.

7. An article of' manufacture including in combination a casinghaving inlet and outlet ends, ports communicating withtatmosphere thru the casing wall between the two ends, the inlet end forming pressure scaled connecting means for a source of pressure fluid supply, together with a tubular sleeve valve member made or shape resumingdeformable material, one end extended into the inlet end of said casing, andtoward the outlet and overlying said ports, one end of the sleeve provided with'angannular shoulder concomitant with said inletiend of said casing, .21

cage of relatively rigid material juxtapositioned with said annular shoulder and means forming a baflle extended across the inside and intermediate of the ends of the sleeve, check valve means formed by the juxtaposition of said sleeve wall, and said baffle, a second check valve formed by that end of said sleeve that is toward the outlet end, same being inturned and bordering a slitted passage for pressure fluid, whereby abnormal internal pressure will be efiective to open both check valves and expand said sleeve to close the casing ports, abnormal external pressure acting to collapse said sleeve and urge the slitted end toward said bailie closing said outlet passage, under the efiects of further excessive external pressure.

8. A device as of claim 7 wherein the slitted end of the sleeve is lipped, same being urged against said baflle thereby preventing the slitted end from being opened by excessive external pressure and being completely reversed thru the cage openings.

9. A device as defined by claim 7 wherein the sleeve valve member is divided into two chambers located on oppoiste sides of the bafile, one chamber located on the inlet side with a second chamber located between the slitted end and said baffie, whereby in event of excess internal pressure reversing the lipped end of the sleeve member into the second chamber, said baffle interceding will prevent the lipped end from being urged thru the openings of the cage.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 127,038 Field May 21, 1872 155,668 Painter Oct. 6, 1874 280,212 Miles June 26, 1883 2,098,886 Safiord Nov. 9, 1937 2,113,615 Farmer Apr. 12, 1938 2,270,737 Langdon Jan. 20, 1942 2,322,631 v Groeniger June 22, 1943 2,371,449 Langdon Mar. 13, 1943 2,382,427 Langdon Aug. 14, 1945

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US127038 *May 21, 1872 Improvement in flexible lip-formed valves
US155668 *Sep 19, 1874Oct 6, 1874 Improvement in valves
US280212 *Dec 26, 1882Jun 26, 1883 Peters
US2098886 *Oct 20, 1936Nov 9, 1937New York Air Brake CoExhaust port protector for air brakes
US2113615 *May 7, 1936Apr 12, 1938Westinghouse Air Brake CoVent protector
US2270737 *Jul 26, 1940Jan 20, 1942Langdon Jesse DSiphon breaker and valve
US2322631 *Jun 13, 1940Jun 22, 1943Pierce John B FoundationCombined vacuum breaker and check valve
US2371449 *Dec 12, 1942Mar 13, 1945Langdon Jesse DValve
US2382427 *Sep 9, 1941Aug 14, 1945Langdon Jesse DSiphon breaker and valve
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2912999 *Jul 18, 1955Nov 17, 1959Kersh Ronald CFluid check valve
US3034731 *Mar 4, 1959May 15, 1962R E Chapin Mfg Works IncBack flow preventing valve assembly
US3122156 *Oct 21, 1959Feb 25, 1964Kersh Ronald CFlexible check valve
US3125114 *Aug 15, 1960Mar 17, 1964 Dual valved vacuum breaker
US3307571 *Apr 13, 1964Mar 7, 1967Maytag CoVacuum breaker
US4893644 *Aug 31, 1988Jan 16, 1990Sirio S.P.A.Non-return valve for supply cocks
US4924923 *May 17, 1989May 15, 1990Vernay Laboratories, Inc.Fuel filler pipe seal
US5117863 *Mar 18, 1991Jun 2, 1992Pepsico Inc.Backflow valve
US5176173 *Feb 13, 1992Jan 5, 1993Pepsico Inc.Backflow valve
US5217040 *Mar 4, 1991Jun 8, 1993Kwc AgSafeguard for a sanitary fitting
US5277171 *Feb 2, 1993Jan 11, 1994Bradford-White CorporationWater heater heat trap
US5454396 *May 23, 1994Oct 3, 1995Kwc AgSanitary safety device for preventing the backflow of water
US5551483 *Aug 17, 1994Sep 3, 1996Kwc AgBackflow-preventer
US5564460 *Jul 21, 1995Oct 15, 1996Sloan Valve CompanyDouble seal vacuum breaker
US5842503 *Aug 14, 1997Dec 1, 1998The Excello Specialty CompanyIntegrally formed air flow valve
US6119713 *Nov 4, 1998Sep 19, 2000Pino; Wilton J.Apparatus to prevent rapid multiple flushing
US6273124May 25, 2000Aug 14, 2001Donald G. HuberCheck valve floor drain
US6318397Aug 3, 2000Nov 20, 2001Donald G. HuberSide port floor drain
US6554018 *Oct 24, 2001Apr 29, 2003Wilton J. PinoWater closet flushing system
US6719004Jul 25, 2002Apr 13, 2004Donald G. HuberCheck valve floor drain
US7270087Sep 14, 2004Sep 18, 2007Bradford White CorporationHeat trap
US8826937 *Mar 3, 2011Sep 9, 2014Masco Canada LimitedFlush valve anti-backflow cartridge
US9010363Mar 13, 2014Apr 21, 2015The Rectorseal CorporationDrain valve
US9139991Jan 31, 2012Sep 22, 2015The Rectorseal CorporationFloor drain valve with resiliently mounted rigid flappers
US9416986Dec 22, 2014Aug 16, 2016The Rectorseal CorporationValve for roof vent
US20060054110 *Sep 14, 2004Mar 16, 2006Allpass CorporationHeat trap
US20060118172 *Dec 2, 2005Jun 8, 2006Feng-Yu WuOne-way valve having vacuum breaking and flow-guiding functions
US20110030132 *Aug 10, 2009Feb 10, 2011Ladislau BiroMulti-function cleanout plug and method of use
US20110036417 *Dec 22, 2008Feb 17, 2011McAlpine & Co. LimitedPlumbing sealing arrangement
US20110226357 *Mar 3, 2011Sep 22, 2011Stauder Frank AFlush valve anti-backflow cartridge
US20140311979 *Nov 17, 2011Oct 23, 2014Alexander SchluttigDevice and Method for Producing Sterile Water by Means of a Cross-Flow Liquid Sterile Filter
DE1011234B *Oct 7, 1954Jun 27, 1957Eisen & Stahlind AgRueckflusssicherung
DE1092221B *Jul 26, 1958Nov 3, 1960Bopp & Reuther GmbhRueckflussverhinderer fuer Wasserzaehler
DE1106568B *Apr 11, 1956May 10, 1961Bopp & Reuther GmbhMembranrueckschlagventil, dessen Membran in der Mitte einen elastischen Druckknopf traegt
DE1154982B *Jan 30, 1957Sep 26, 1963RenaultRueckschlagventil
EP0639675A1 *Jul 27, 1994Feb 22, 1995Kwc AgBackflow prevention valve
EP0684416A1 *May 19, 1995Nov 29, 1995GALATRON S.r.l.Hot and cold water mixer valve with built-in anti-backflow device
EP1174549A3 *Jul 18, 2001Jan 12, 2005Michel Jacques SenteurBackflow-preventer
EP2620334A3 *Oct 14, 2009Aug 20, 2014Valeo Systèmes d'EssuyageReturn and ventilation valve for a washing unit used for vehicle windows
EP3138973A1 *Sep 2, 2016Mar 8, 2017Swiss Invent AGOdour trap for a sanitary water drain
WO1992014888A1 *Feb 20, 1992Sep 3, 1992Ac Developments LimitedWaste valve fittings
WO2002103233A1 *Jun 19, 2001Dec 27, 2002Huber Donald GCheck valve floor drain
WO2016116572A1 *Jan 21, 2016Jul 28, 2016Deutsches Institut Für Lebensmitteltechnik E.V.Sound absorber for vacuum grippers
U.S. Classification137/218, 220/86.1, 137/512.4, 137/512
International ClassificationF16K15/14, E03C1/10
Cooperative ClassificationF16K15/147, E03C1/10, F16K15/145, F16K15/148
European ClassificationF16K15/14J, E03C1/10, F16K15/14H3, F16K15/14H2