Measuring Device for Water Flow in a Buried Pipe

This invention relates to a measuring device to determine water flow rates through a submerged pipe.

As is perhaps well known, in the past it has often been a problem to measure the condition of submerged pipes, namely, the amount of sediment in a pipe, the rate of flow in the pipe, and the depth of water flowing in the pipe.

This invention is of a device which has as an object (a) provision for measuring the depth of sediment on the floor of a generally horizontal sewer pipe accessible through a vertical shaft or manhole passageway and which is arranged below ground level and (b) the depth of water flow above the sediment in the pipe and (c) the rate of flow of the water in the pipe.

It is a general object of this invention to provide an improved measuring device for determining water flow rates in a submerged pipe which includes a first shaft with a sleeve movable with respect thereto so that the lower end of the shaft is adapted to be positioned on the floor of the pipe and the lower end of the sleeve is adapted by reason of axial displacement when it rests on a layer of sediment in the pipe to measure the depth of the sediment and a float tethered to the sleeve which floats on the water and is supported thereby and which includes a signal to indicate when the float is supported by the water instead of on suspension means which are provided to support the float when under the influence of gravity alone and which additionally, includes an apparatus for measuring the rate of flow of water past the float, whereby the information measured may be utilized in the manner set forth more fully hereinafter to measure the rate of flow of water through the pipe.

In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of the device illustrating the use thereof;

FIG. 2 is a side elevation view of the measuring device;

FIG. 3 is a view in cross section taken on the plane indicated by the line 3--3 of FIG. 2 and looking in the direction of the arrow;

FIG. 4 is a top plan view of the device shown in FIG. 2; and

FIG. 5 is a circuit diagram illustrating the electrical portion of the instant invention;

Referring to FIGS. 1 and 2, the device is seen to include a shaft 12 with an upper end 14 and a lower end 16 and of a length to reach from the upper end which is above ground level to the floor 18 of a buried pipe 20. The lower end 16 is preferably pointed, as shown, to pierce a sediment layer 22 which is usually to be found on the floor of such a buried pipe. It is adapted, therefore, to be forced through the sediment until the tip is in engagement with the pipe floor as shown in FIG. 2. An elongate sleeve 30 is telescoped over the shaft 12. The sleeve is of a length which is less than that of the shaft but, generally, similar to it. It has an upper end 32 and a lower end 33. To the lower end, a plate 36, preferably disc-shaped, is fixed in perpendicular relation to the shaft; and it is adapted to rest on the surface of sediment in the pipe. Means are provided to measure the axial displacement of the lower end of the shaft and the disc on the lower end of the sleeve which may be in the form of mutually intercooperating means on the upper end of the sleeve and upper end of the shaft. To this end calibrations, as at 40 on the upper end zone 14 of the shaft are provided which indicate the distance between the plate and the lower end of the shaft. This is seen as a measurement of the depth of sediment in the pipe. Structure, now to be described, is slidably captivated on the sleeve for vertical movement therealong, i.e., between the disc and toward the upper end of the sleeve. The structure is generally designated by the numeral 50; and it includes: (a) a slide means engaging the sleeve, which may be an upper ring and a lower pair of slide plates 52 and 54 in spaced relation from one another and in engagement with the sleeve, (b) a boom 56 extending laterally from the slide means on a frame 58 which includes the boom, and (c) a float means suspended by a flexible tether from the boom. The float means, which may comprise a first and a second elongate body 62 and 64, as shown, are suitably connected together by brackets 66 and 68 defining a space 70 between them. The float means is adapted to float on the water level in the pipe; and it includes a forward end zone 72 and a rearward end zone 74.

In the preferred embodiment shown, the flexible tether comprises a strand 76 connecting the boom to the float at its forward end zone 72 and a strand 78 connecting the boom 56 to the rearward end zone 74 of the float means. The two strands orient the float means, preferably in a generally horizontal attitude when the float is suspended and the strands are taut or under tension when supporting the weight of the float means.

In use, the shaft is inserted until the point 16 rests on the floor 18 of the pipe. Thereafter, the sleeve is moved downwardly in telescoped relation along the shaft until the surface of the plate or disc rests as shown in FIG. 2 on the surface of the sediment. The depth of the sediment may then be measured upon reference to the calibrations 40 on the upper end of the shaft. The slidable structure is then moved vertically with respect to the sleeve. As it is moved upwardly or downwardly the weight of the float means will exert tension on the strands or the tension on the strands will be reduced or slackened as the weight of the float means is taken up by the buoyancy effect as it engages the water. In a preferred embodiment the strands are such as to be free hanging when the float is supported by the water. The forward end 72 of the float is tethered to a line such as 80 which connects it to the slidable structure.

The sliding structure is raised and lowered by a tubular cable 82 which is connected at its lower end zone 84 by a connector 86 to the slidable structure, as at 88, which is, generally, at its center of gravity. It is thus seen that an upwardly directed force transmitted to the sliding structure through the cable will lift the float until it is in a suspended condition with the weight thereof carried by the strands 76 and 78 which are taut until such time as the float means is lowered and the weight of the float is taken up by the buoyant force of the water acting on the float means, at which time the lines 76 and 78 will slacken.

Signal means are included to sense a relaxation of tension in one of the strands, such as the forward strand 76 as the float means engages the water and becomes supported thereby. This signal means may comprise a switch 79 in a circuit and which switch includes a switch arm 81 normally spring-urged into a first position but yieldable when tension is removed from it, i.e., in the condition shown in FIG. 2, so that current will flow through the circuit indicated by the conductor lines 90 and 92 when the tension on the line 76 is relaxed. The spring means indicated by the numeral 94 urges the arm 81 of the switch 79 into the normally open position. Through the conductor lines 90 and 92, which pass through the tubular cable 82, a light 100 in FIG. 1 will be energized from a source, such as a battery, included in the housing 101. At the instant the light comes on, the cable is a measure of the depth of the water in the pipe and can be determined in relation to the length of the pipe and the depth of sediment in the bottom of the pipe.

Means are also provided to sense the rate of waterflow through the pipe. These means include a circuit 102 which includes a meter 104 electrically connected to a sensor 106. The sensor includes a member 108 movably supported by the float means and means constraining that movable member to a predetermined path of movement with a portion of the member 108 at all times extending below the normal waterline of the float means, which is indicated by the water pipe or rotation of the finned rotor.

It is thus seen that one utilizing the device and knowing the cross sectional area of the buried pipe may, with the measured information determined as set forth above, determine the cross sectional area of the water which is flowing and, additionally, the rate of its flow through the pipe. Thus, the condition of a pipe below the surface may be measured for maintenance and delivery rates which is important in measuring and planning sewerage and water delivery systems and a device has been provided whereby measurements may be taken through a manhole shaft or passageway of (a) the depth of sediment on the floor of a generally horizontal sewer pipe accessible through the passageway and below the ground level, (b) the depth of water flow above the sediment in the pipe, and (c) the rate of flow of the water in the pipe.