Patented Oct. 15, 1946 2,409,582 UNITED STATES PATENT OFFICE 2,409,582 BACKWATER VALVE Samuel Olson, Chicago, Ill. Application October 26, 1944, Serial No. 560,444 1 s claims. (o1. 18a-1) 2 This invention relates to drainage systems, par same is not limited to the particular form herein ticularly as employed in domestic and industrial shown and described, except in so far as indicated buildings, for discharging waste matter and water by the appended claims. into municipal sewer systems or other drainage' It is quite common, during a heavy rain storm facilities. 5 or in the time of floods, for municipal sewers to One object of the invention is to prevent the become so overtaxed that the water in the sewer sewer water from backing up under flood condi rises until it backs up into the drainage conduits tions and overflowing into the various waste out leading from homes and other buildings, and lets in a building. , p overflows onto basement floors or even through Another object of the invention is to provide drain outlets at more elevated positions in the automatic means responsive to an excessive rise building, >causing great inconvenience and con in the level of the water in a sewer and operative siderable damage. This invention is designed to to close a valve controlling a drain pipe connect automatically prevent such occurrences by clos ing the sewer with a building. ing a valve positioned at a relatively low levelinY A further object of the invention is to provide 15 the drain discharge pipefrom a building so as to a back water valve for the purpose indicated ar prevent the sewer water from rising above that ranged to be moved slidably onto its seat with a point in the discharge pipe. self cleaning action for removing accumulated The back water valve structure which serves debris or other matter encrusted on the valve this purpose is enclosed in a chamber I which is seat. 20 interposed in the drain conduit and which has It is also an object of the invention to provide, an inlet 2 and an outlet 3. A fragment of the in a drain passage leading from a building to a conduit leading from the building is shown at 2a sewer or other outlet, a chamber closed except and~ a fragment of the conduit leading to the for an inlet and. outlet by which it is connected sewer is shown at 3a. The inlet is provided with into the passage, and containing a float respon 25 an elbow 4 within the chamber I and terminating sive to liquid level in the chamber, a valve mount in a downwardly discharging opening having a ed for movement into position to close the inlet valve seat 5 adapted to be closed by the valve and operative connections between the float and member 6 which is slidable thereover. The valve the valve by which the valve is closed when the member is suspended in the chamber I by a pair level of liquid within the chamber exceeds a pre 30 of links 1, 'I pivotally connected to the Valve at determined limit. opposite sides thereof as shown at 8, these pivotal Other objects and advantages of the invention connections being aligned , at an axis disposed will appear from the following description taken approximately midway between the forward and in connection with the drawing in which : rear edges of the valve. An additional link 9 is Fig. l is a vertical sectional view of a chamber :t: In connected to the valve adjacent its rear edge. All arranged in accordance with this invention and the links are swung from a point near the top of including a back water valve and a ñoat con the chamber, the link 9 being pivoted to a bracket nected for operating the same, the section being I0 and the link 'I extending from'a cross bar II taken substantially as indicated at line I--I on v with springs I2 interposed between the cross bar Fig. 2. 40 and the nuts I3 on the upper ends of these links Fig. 2 is a vertical section taken substantially for yieldingly tensioning the link ‘l and thus urg as indicated at line 2_2 on Fig. 1 and with the ing the valve member 6 against the seat 5 at all valve in open position. \ positions of the Valve. To avoid tilting the valve Fig, 3 is a vertical sectional view similar to Fig. in its sliding movement across its seat the lower 2 but with certain parts shown in elevation and 45 end of the link 9 is provided with a slot 8a engag-l with the valve shown in closed position. ing the pivot I4 by which the link is connected to Fig. 4 is a horizontal section taken as indicated ' the valve. ' at line 4-4 on Fig. 2 and showing the mechanism It may be understood that the valve 6 is nor- y in plan. mally open as shown in Fig. 2, with the drain While there is shown and described herein cer 50 age flowing from the inlet conduit 2e through tain specific structure embodying the invention, the inlet 2 and elbow 4 and discharging against it will be manifest to those skilled in the art that the floor I5 of the chamber I. This floor I5V various modifications `and rearrangements of the slopes toward the outlet 3 through which> the parts may loe-made without departing from the drainage Apasses into the conduit 3%, but in the spirit and scope of the invention, and that the. 55 event ‘of flood conditions, such that the water 2,409,582 3 4 backs up in the pipe 3a and starts to rise in the chamber 2, a float I6 in the chamber will be elevated as the water level rises therein. rFhis float is guided loosely for vertical movement be tween one wall of the chamber I and a tra-ns versely extending guide member I‘I and is pro vided with upwardly extending arms I8, IB con nected by a cross bar I9 and pivotally attached to the arms 2S, 2B secured to the rock shaft 2i which extends across the chamber I and is jour naled on the side walls thereof as shown in Fig. 1. up beyond the float chamber. The device re quires no attention for maintenance, and will automatically reopen the connection between the The single arm 22 extending downwardly from ' drain pipe and the Sewer as soon as the level of water in the float chamber has receded upon cessation of flood conditions. Even though the mechanism may be inactive for long intervals, any scum or encrustation accumulating on the valve will be scraped clean by the first closing move ment of the valve member insuring effective seat ing thereof. I claim as my invention: ` 1. In combination with a sewer drain conduit, the rock shaft 2l is connected to the link 9 bya a chamber interposed therein having an inlet and pivot 23 engaging a float I6 thus swings the arms anr outlet, the inlet entering the chamber above 20, 2U upwardly and rocks the shaft 2| in a di the level of the outlet and terminating in an el rection to swing its arm 22 forward, that is, to bow discharging downwardly in the chamber ward the terminal elbow 4 of the inlet, so that through a downwardly facing valve seat, a nor the link 9 is thereby moved in a direction to mally open valve disposed out of the path of ñow slide the valve 8 over the seat 5 to the closed 20 when in open position, said valve being slidable position illustrated in Fig. 3. across said seat to close the inlet against back Since flood conditions which operate to close flow, and a float in the chamber with means con the valve 6 occur only occasionally there may necting said ñoat to said valve for sliding it to be some accumulation of debris or solid matter closing position over the seat in response to a encrusted on the upper surface of the valve E rise of liquid in the chamber above a predeter but the valve seat 5 is formed by a flange en mined level. circling the terminal outlet of the elbow á, and 2. In combination with a sewer drain conduit, the outer edge of this flange is beveled to an acute a chamber interposed therein having a down edge at 5a so that as the valve t slides across the wardly discharging inlet and an outlet, the inlet seat 5 the sharp edge 5ab acts to shear from the upper surface of the valve 6 any encrusted ac 30 terminating in a downwardly facing valve seat disposed above the level of the outlet, a normally cumulation so as to insure effective seating of the open valve disposed out of the path of discharge valve. This action is assisted by the springs i2 when in open position, said valve being slidable which constantly urge the valve against the seat across said seat, and a float in the chamber with and into effective engagement with the shearing means connecting said float to said valve for edge ila as the valve moves across the terminal sliding it to closing position over the seat in re seat flange 5 toward its closed position. The sponse to a rise of liquid in the chamber above tension of the springs I2 may be varied by ad a predetermined level. justment of the nuts i3 which are readily acces 3. In combination with a sewer drain conduit, sible upon removal of the cover 25 of the cham a chamber interposed therein having a downward ber I. ly discharging inlet and an outlet, the inlet ter It will be noted from Fig. 3 that a compara minating in a downwardly facing valve seat dis tively limited rise of the float i6 is sufficient to posed above the level of the outlet, a valve slidable shift the valve E to its closed position so that the across said seat, substantially parailel links sus valve will actually close before the flood water enters the inlet conduit 2a leading from the build- ‘ - pended from the upper part of the chamber sup porting said valve by engagement therewith at ing and of course all danger of overflow of the spaced pivot axes, and a float in the chamber fixtures in the building is eliminated. During with means connecting said float to said valve for normal operation, with the valve in open posi sliding it to closing position over the seat in re tion, the waste water entering through the inlet sponse to a rise of liquid in the chamber above a 2 with whatever solid matter it may carry will fall predetermined level, said links including spring directly onto the inclined floor I5 without com means tensioned to yieldingly hold the valve to its ing in contact with the face of the valve 6 and with seat throughout its slide to closing position. almost no tendency to encrust the valve seat 4. In the combination defined in claim 3, said 5 which faces downwardly and in the direction of dow. Accordingly, the valve will tend to keep . ~ Valve seat having its outer rim beveled to an acute edge engaging the face of the valve for itself clean so that there should be a minimum shearing encrusted matter therefrom as the valve of encrusted matter on the upper surface of the moves across said seat. valve iâ to be scraped or sheared off by the bev 5. In the combination defined in claim 3, said eled edge 5ii of the valve seat when flood condi tions cause the valve to be moved to its closed 60 means connecting the float to the valve including a rock shaft having a pair of arms spaced apart position. As a precaution against any possible and connected to opposite sides of the lloat re~ accumulation on the under side of the valve seat spectively, said arms extending in approximate 5, the leading edge of the valve member 8 is ly horizontal direction from the rock shaft, and a beveled to an acute edge as seen at E@ in Figures 2 and 3, so that this edge will have a shearing 65 third arm depending in substantially vertical di rection from the rock shaft and connected to the action for cleaning the seating surface as the valve. valve moves to closed position. 6. In the combination defined in claim 3, said It will be seen that I have devised a relatively valve having its leading edge beveled to an acute simple construction, inexpensive to manufacture and certain in operation, whereby the rise of level 70 edge engaging the face of the valve seat for shearing encrusted matter therefrom as the valve of liquid in the float chamber, which is incident moves across said seat. to backing up of the water from the sewer, will automatically shut off the connection between the sewer and the drainage conduit leading from the building so that the sewer water cannot back 75 SAMUEL OLSON.