US2176540A

US2176540A - Well point and system therefor

Info

Publication number: US2176540A
Application number: US234433A
Authority: US
Inventors: Thomas F Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-10-11
Filing date: 1938-10-11
Publication date: 1939-10-17
Anticipated expiration: 1956-10-17

Description

Oct. 17, 1939. T. F. MOORE WELL POINT AND SYSTEM THEREFOR Filed Oct. 11, 1938 S Sheets-Sheet 1 3 Que n for H 131002? Oct. 17, 1939. 1'. F. MOORE WELL POINT AND SYSTEM THEREFOR Filed Oct. 11, 1938 3 Sheets-Sheet 2 Oct. 17, 1939. 'T'. F. MOORE 1 5 WE'LL POINT AND SYSTEM IHEREFQR Filed Oct. 11, 1938 3 Sheets-Sheet 3 Patented Oct. 17, 1939 g UNITED STATES PATENT OFFICE WELL POINT AND SYSTEM THEREFOR Thomas F. Moore, Morris Plains, N. J. Application October 11, 1938, Serial No. 234,433

18 Claims. (Cl. 166--1) This invention relates to well point systems, and well point construction which can be more readily more especially, to a well point having provision disassembled and reassembled for purposes of for freely passing water or other liquids contained cleaning or repair than has been the case herein the soil, while automatically excluding and protofore.

hibiting the entrance of air and other aeriform Other and further objects and advantages of 5 fluids from entering the well point. the invention will be hereinafter described and the In my copending application Serial No. 183,551, novel features thereof defined by the appended filed January 5, 1938, I have disclosed a well point claims. embodying the automatic feature above referred In the drawings:

to. The present invention has been designed as Figure 1 is-a diagrammatic view of a typical 10 an improvement over the construction specifically well point system embodying a number of well shown and described in that application. points, each of which is constructed in accordance In the usual well point systems composed of with the present invention, and particularly illusconventional well points, it' has been the custrating the manner in which the invention admits tomary procedure in the past to jet all of the well of the practical arrangement of the well points at 15 points to substantially an equal distance below different distances below the header; the header or intake line leading to the pump so Figure 2 is a view in side elevation of my imas to cause the water level in the soil to be proved well point, showing the connecting pipe brought down evenly within the section of the and fittings for connecting the upper end of the system which is controlled by a single pump. well point to a header line; 20

The uniformity of depth of the well points was Figure 3 is an enlarged detailed vertical secessential to a successful operation of the system tional View, taken through the well point; because if in lowering the water level the level Figure 4 is a horizontal sectional view, taken should drop substantially to the lower end of the approximately on the line l-4 of Figure 3;

screened ,intake of one or more of the well points, 'Figure 5 is a horizontal sectional view, taken 25 air would be drawn into these points and sucked through the lower head of the well point on apinto the lines connecting the various well points proximately the line 55 of Figure 3;

to the pump, thereby seriously interfering with Figure 6 is a horizontal sectional view, taken the pumping operation, and often times comapproximately on the line 6- -6 of Figure 3;

pletely rendering the system inoperative. Figure '7 is a horizontal sectional view, taken 30 Through provision of an automatic control for approximately on the line 1-1 of Figure 3; each well point, such control freely admitting Figure 8 is a fragmentary vertical sectional water to the well points but excluding air, it is now view, taken approximately on the line 8-8 of possible and perfectly practical to sink the well Figures 3 and 6;

". points different distances below the header, or in Figure 9 is a composite top plan view of the flatfact to any depth within the range of the vacuum tened conduit and arcuate perforate plate which influence of the pump. This is particularly adtogether form the tubular body of the well point vantageous where the soil characteristics vary at and provide an axially open jetting-and-suction different places within the area which is served passage through One Si Of t b y and a v by the well point system, and where the Water level chamber at the other side, when the edges of the in the soil is at different elevations below ground arcuate plate are secured to the corners of the level. flattened conduit as by welding;

The primary object of the present invention is Figure 10 is a bottom plan view of the float to provide an automatic well point of the type member; 5 above referred to, which is somewhat simpler in Figure 11 is a bottom plan view of the resilient construction and more economical in manufacpressure member which coacts with the float valve turing cost than the conistruction disclosed in my to insure effective cooperation of the float valve aforementioned copending application. with its seat at the bottom of the float valve; and A still further object of the invention is to pro- Figure 1 is D ViGWOf a b ank of flexible vide an improved well point assembly which is material of which the float valve is preferably 50 sealed to a better degree against the entrance of comp air into the Well point, having particular regard Referring to Figure 1, I designates a header to for the fundamental aim of the automatic control which is connected a plurality of well points 2 to positively exclude air. which have been sunk into the soil to the desired Another object of the invention is to provide a depth or depths so as to enable the liquid (gen- 55 orally water) contained in the soil drawn therefrom. A suction pump 3 of any suitable type is connected to the header i of an intake connection 4, while the sideofthepumpiisconnectedtoa linelwhichmayleadtoastoragetank or where, as desired. In the case of the typical point system illustrated in Figure l, the we storedinthestoragetanklforsuchuseas casion requires, the tank I being connected a supply line I through which the water ma directed to fire hydrants I and/or ot where the water is to be availed of.

well pointsiissoconstructedaswili after more fully appear, as to permit the entrance of water into the same so that it be withdrawn from the soil by the pump 8, positively prohibits the entrance of air into system. Accordingly. the well points may be sunk to different depths, as shown, and need not be all sunk the same distance as heretofore required in such a system to insure uniform lowering of the sea? water level in the soil throughout the whole area erably spaced from three to nine feet apart, depending upon the amount of water contained in the soil and the characteristics of the soil. The principal limitation which is to be taken into consideration is that the well points must not be sunk to a depth greater than the range of vacuum or suction influence of the pump. It is to be understood that my new well point is not limited to use in the particular system illustrated in Figure 1 of the drawingssince it is equally adaptahleto any of the various uses to which the ordinary well point may be put.

Referring now to the construction of the well point itself, and referring first to Figure 2 of the drawings, it will be seen that the well point is tubular in form and is substantially uniform in size from end to end, so that there are no proiections which will interfere with the sinking of the well point into the soil. The central portion of the well point includes a foraminous filter screen I of substantial area, which lies between and is coaxial th axially spaced upper and lower heads I. and ii, respectively. Extending upwardly from'the upperghead II is a riser II, which is provided at its upper extremity with suitable connections and fittings I! for connecting the well point to a header such as the header l in Figure 1'or to a flexible conduit such as is ordinarily used in connecting the well point to a source of jetting fluid for the purposes of jetting the well point into the soil. While the well point is preferably so constructed as to enable the same to be Jetted into the soil, it may be sunk otherwise if preferred.

The upper head II is preferably threaded internally to receive the threaded lower end of the riser l2. Around the bottom of the head Hi there is provided an annular recess II, for a purpose which will hereinafter, more full appear. A fioor ll extends across the lower end of the head ll, said floor being provided with an opening ll of generally D-shape to permit the free e of water through the head II. If desired, the floor ll may be provided with an inclined baiiie It disposed within the head It to aid in guiding the water towards the opening I I during its downward movement through the head without creating any material turbulence within the head. As shown in Figure 3, the floor H and baiiie It are constructed separate y from the at the corners of the latter in any suitable manner, such as by tack-welding the edges to the pipe at intervals. when so connected, the arcuate plate it substantially constitutes a continuation of the arcuate side of the flattened pipe l'I so that the two together form a body whichis substantially circular .in cross-section. The fiattened side II of the pipe I! thus constitutes a partition between the axially open passage 2i within the pipe i1 and the space 22 defined within the wall It formed by the plate at the oppodte side of the partition, as will be best understood from reference to Figure 9. when the pipe i1 and the plate II have been'alsembled as Just described,theyaresuitablyconnectedtothe head ll,asbywelding, withtheopening llin the floor it registered with the-passage ii, and the imperforate portion of the floor ll disposed across the upper end of the space 22. me passageilwithinthepipe ii constitutesandwillbe hereinafter referred to as a Jetting-and-suction passage-this by reason of the fact that the letting fiuld passes downwardly through this passage during theietting operation, and the water withdrawn from the soil upwardly through the same passage during the suction operation. The space 22 within the arcuate wall ilconstitutesa float chamberandalsoafiltrate chamber, the latter resulting from the fact that thewater from thesoil passesinto'thi's chamber through the perforations it after first passing through a filter screen 23 which surrounds the body of the well point intermediate the upper and lower heads II and II." The filter screen 23 is preferably constructed in accordance with the disclosure in my Patent No. 2,090,545, granted August 17, 1937, which is to say that the screen is of laminated construction having inner and outer coarsely foraminate layers and an intermediate relatively finely foraminate layer. The upper end of the tubular screen lies in the annular recess it around the lower end of the upper head it, where it is secured to the head, as by welding, thus preserving the continuity and uniformity of size of the well point from end to end.

The lower ends of the pipe i1 and arouate wail II which form the body of the well point have preferably secured thereto aring 24 forming a radially outwardly proi flange, against which the lower extremity of the tubular filter screen 28 abuts, and to which this end may be secured by welding. The lower extremity of the partition is preferably thickened or built up to provide a bead, as at 25, and the lower end of this head, together'with the lower end of the annular flange 24 are faced of! to provide perfectly smooth, coplanar surfaces of appreciable area. Secured to the ring 24 and extending downwardly therefrom is a plurality of studs 26 (preferably three) which serve to detachably -secure the lower head II to the body of the well point. Intermediate the lower head H and the ring 24, there is disposed a plate 21, which is preferably composed of a relatively soft metal, such as lead or the like, to constitute a more or less flexible gasket between the ring 24 and the a head II and thereby insure the provision of a substantially air-sealed connection between these parts. The plate 21 is provided with an aperture 28 registering with the jetting-and-suction passage 2|, and also with a group of perforations 5 29 registering with the lower end of the float chamber 22. The plate 21 is suitably apertured, as at 30, near its outer edge to receive the studs 26 therethrough.

The lower head H is reduced in diameter near its upper end, as at 3|, so as to provide an annular groove or channel about the same. Openings 32 in the head II, and corresponding with the openings 30 in the plate 21, are provided to receive the studs 26. When the head i I is assembled on the studs 26 and the nuts 33, and lock washers 34 are applied onto the threaded extremities 35 of the studs 26, the nuts and washers will be disposed within the annular groove or channel of the head. Assembly of the lower head and removal thereof can thus be accomplished by a very simple operation, as will be obvious from Figure 3-of the drawings. When the assembly is complete, the nuts 33, being located within the annular groove or channel in the lower head cannot interfere with the sinking of the well point into the soil, and when the nuts are tightened up, the plate 21 will be tightly clamped between the upper end of the lower head II and the lower end of the well point body and maintain the parts sealed against the entrance of air at this connection.

In the upper end of the lower head N there is provided a chamber 36, normally establishing communication between the lower end of the jetting-and-suction passage 2| and the float valve chamber 22 through the opening 28 and perforations 29, respectively registering with this passage and chamber. Within the chamber 36 is located a rigid disc valve 31 (preferably'composed of brass) which is of a size suflicient to cover the entire group of perforations 29 in the plate 21 when seated against the lower side of the plate over-the perforations. Fixed within the valve chamber 36 and lying horizontally on the bottom of the chamber at opposite sides of the upper end of the central passage 38 through the reduced portion of the lower head II is a pair of small spacer rods or bars 39, upon which the d sc valve 31 is normally adapted to rest, as shown in full lines in Figures 3 and 4. Rods or bars 39 are bent vertically upwardly at their ends, as at 40, so as to aid in guiding the disc valve 31 towards and away from the perforations 29, and prevent the disc valve from becoming laterally displaced in the valve chamber 36, as will hereinafter more fully appear.

Mounted within the lower end of the lower head H is a floating ball-check valve 4| which is normally in floating engagement with a beveled seat 7 42 at the lower end of the passage 38. Guide ribs- 43 within the lower chamber 44 in the head serve to guide the valve 4| into engagement with the seat 42. A pair of rivets 45, extending transversely through the head I at opposite sides 75 of the axis thereof serves to normally retain the ball-check valve in the chamber 44 and to limit the axial movement of the valve 4| away from its seat 42. These rivets also prevent stones and other relatively large material from crowding up inside of the chamber 44 where they might interfere with the seating of the valve 4| or ultimately become sucked up into the well point body. The lower extremity of the head H is preferably serrated to provide teeth 46 toaid in displacing the soil below the well point as the well point is sunk into the soil.

Reverting to the float valve chamber 22, there is provided in this chamber a float body 41 of a size somewhat smaller than the chamber'so as to permit the float body to freely move axially therein.- The float body may be of any suitable construction, and flxed to its upper end is a relatively light compression spring 46 arranged so that its free end is adapted to abut against the floor l4 which lies across the upper end of the chamber 22. Fixed to the lower end of the float body 41 by one or more fastenings 49 is a flexible valve 59. This valve is preferably composed of sheet rubber, leather, or the like. A generally rectangular blank of such suitable material is cut, as shown in Figure 12, and the ends of the blank are folded upwardly and inwardly towards each other and are then attached by the fastening or fastenings 49, hereinbefore referred to, to the bottom of the float body 41, leaving the portion of the blank intermediate the ends loosely suspended below the float body and freely movable towards and away from the same. When the level of the water which collects in the chamber 22 is high enough to raise the float body 41 in this chamber to the position shown in broken lines in Figures 3 and 8, the loosely suspended portion of the flexible valve 50 will assume a position spaced above the perforations 29 in the plate 21 below the chamber 22, as shown best in dotted lines in Figure 8. As the water level falls in the chamber 22, the float body 41 will automatically descend until the flexible valve 59 rests upon the plate 21, thus flattening out the loosely suspended portion of the flexible valve 50 so as to cause the same to cover and close oil the entire group of perforations 29, as best shown in full lines in Figure 8. A pressure plate 5|, having downwardly curved arms or

fingers

52, 52 extending therefrom at opposite sides and formed of resilient material such as spring metal, is interposed between the bottom of the float body 41 and the flexible valve 50 to aid in pressing the valve 50 evenly against the plate 21, thereby assuring substantially even contact of the valve over the perforations 29 so that air cannot pass by the valve through the perforations 29. The pressure member 5| further contributes to the preservation of the shape of the valve body 50, which, in its suspended condition, is transversely arouate. As the float body 41 rises in the chamber 22, the flexible valve 50 is yieldingly and gradually lifted off the plate 21, commencing at the opposite ends of the valve, resulting in a substantial peeling of the valve from its. seat and thereby progressively uncovering the perforations 29 from the opposite ends of the group of perforations towards the center of the group. Because of this peeling action, so-called, the valve 50 will operate freely responsive to the buoyancy of the float body 41, and without requiring too large a float body to produce the required buoyancy. The action of the float body 41 and flexible valve 50 is substantially the same as disclosed in my copending application hereinbefore referred to.

Having described the structural details of my improved well point. the operation thereof will be briefly summarised as follows:

The well point. in its assembled condition as shown in Figure 2, is preferably jetted into the soil by connecting the connections and flttings l2 to a suitable source of letting water through means of a flexible hose leading from the supply. Thereupon, the letting water is forced downwardly through the well point while the well point is held in a substantially vertical position over the spot where the well point is to be sunk, so that the force of the letting water discharged downwardly through the bottom of the lower head I I will act upon the soil below the well point to erode and displace the soil and allow the well point to progressively sink downwardly. The Jetting operation may be aided by rotating or oscillating the well point so that the teeth on the lower extremity of the lower head II will loosen the soil in the well known manner.

As the letting water passes downwardly through the riser II, it enters the upper head it and is directed through the opening II in the floor it into the jetting-and-suctlon passage 2| through which the water passes downwardly. From this passage II, the water passes through the opening II in the plate 21 into the valve chamber It in the upper end of the lower head,

H, where it acts upon the lower side of the'disc valve 31 to automatically elevate this valve to the position shown in dotted lines in Figures 3 and 8, thereby closing on the perforations 20 in the plate 21 and preventing the letting water from entering the float chamber 22 from which it would otherwise escape outwardly through the perforations it and fllter screen 22. Since the jetting water cannot enter the chamber 22, as a result of the closing of the perforations 2| by the valve 31, it must pass downwardly through the w. 88 in the lower head ii, forcing the floating ballcheck 4} downwardly away from its seat 42 to the dotted line position shown in Figure 3, which allows the jetting water to enter the lower chamber 44, from which it is discharged at the bottom of the head ll. Thus substantially the full pressure of the letting water is effective at the bottom of the well point for causing erosion and displacement of the soil.

when the well point has been sunk to the desired depth, the connections and fittings l2 are disconnected from the source of letting water and are then connected to a suitable pump or suetion apparatus for causing the water in the soil to be drawn into the well point and upwardly therethrough where it can be conveyed to and discharged at any convenient point. Where it is desired to drain a large area of soil, or to provide a supply of water which is greater than can be conveniently handled by a single well point, a proportionate number of well points may be sunk at different places as illustrated in Figure 1, and the well points connected to one or more header lines I, which in turn are connected to one or more pumps 3, accordingto the capacity of the P p- During the suction or drainage operation, the water from the soil inwardly through the filter screen 23 of each well point, and thence through the perforations I! in the wall I. of the float chamber 22 which also constitutes a filtrate chamber. If the water level in the soil, and consequently in the float chamber, is high enough,

the float body. will rise in the chamber, lifting the valve II oi! the perforations 2| in plate 21, thereby allowing the water to be sucked downwardly from the'chamber 22 through the periorations 2| into the upper chamber II in the lower head H. During the auction operation, the floating ball-check II will assume its full line position shown in Figure 8 against the seat 42,-

thereby closing ofl the lower end of the well point and preventing mud, sand, stones and other icreign matter from. being sucked up into the well point. The disc valve I! also automatically assumes its full line position in Figure 8 during the suction operation, resting upon the rods or bars 38 in spaced relation to the perforations 28. From the chamber 86, the water is sucked up through the opening "into the jetting-and-suction e II from which it upwardly through the opening II in the floor it, into the upper head It and riser II, which conducts the water to the surface of the ground, and from the upper end of which it is conveyed to the desiried point of storage, use or discharged as waste.

It the level of the water in the soil should be drawn down substantially to the bottom of the well point, or if for any reason the flow of water into the well point should diminish to such an extent as to tend to cause air to be sucked into the well point during the suction action, the float valve 50 will automatically function to exclude air by closing the perforations 2t and interruptlng communication between the float chamber 22 and the jetting-and-suction passage 2|. In other words, when the water level in the float chamber 22 falls. the float body 41 descends in the float chamber, bringing the valve 80 into seating engagement on the upper side of the plate 21, thereby closing the perforations 28. The valve 50 is held tightly against its seat by the weight of the float body ,ll, which is evenly distributed on the valve by the resilient pressure member I i thereby assuring substantially even contact of the valve over the perforations 2! so that no air can pass by the valve. There is sufllcient space between the top of the float body 41 and the plate ll to enable the float body to rise far enough to lift the valve 50 completely of! its seat and uncover the perforations 29. Upon resumption. of a condition under which the water in the soil is present in sufllcient quantities to justify further withdrawal of the water from the soil, the water will rise in the float chamber 22 and automatically cause the valve II to be stretched and peeled oil the perforations 2!. When .this occurs, the

" float body 41 Jumps to the top of the float chamher, and the spring 48 acts as a buffer to prevent the float body from striking the plate It so hard as to damage the float body. As soon as the valve has been elevated sufflciently far to uncover the perforations 29, the water in the float chamber 22 is permitted to flow downwardly through the perforations 2! into the chamber 38 from which it is withdrawn upwardly through the opening 28, passage 2i and opening it into the head Ill, and thence upwardly through the riser i2, finally emerging into the header line I of the system. It will. be understood from the foregoing that the well point will admit water up to the limit of its capacity, but will automatically exclude air and prevent the same from being drawn into the well point so that air cannot interfere with the operation of the well point system. The size of the jetting and suction passage 2| formed by the flattened pipe i1 is determined according to the 7s desired capacity of the well point. The perforations l9 are preferably of sufllcient size and numher to pass many times as much water as the passage 2| is capable of handling at the same velocity. The reason for this relationship is that it is very desirable to have the entrant water pass through the filter screen 23 with a very low velocity in order to minimize any movement of fine material which would tend to clog the screen. A slow entrant velocity of the water through the screen 23, which has a large surface area, results in a very low carrying capacity respecting fine material, and thus tends to keep the screen clear at all times. screen into the well point, it can be drawn through the well point and to the discharge point with as great velocity as can be created or as desired.

Since the perforated wall l8 has a substantial surface area, for the reasons given above, the cross-sectional area of the chamber 22 may be greater than the cross-sectional area of the passage 2!. As shown in the drawings, the area of the chamber 22 is greater than half the crosssectional area of the tubular body of the well point as a whole.

Through reason of the disposition of the lugs 26 and nuts 33, which serve to removably secure the lower head H to the body of the well point, in the manner 5': own in the drawings and hereinbefore described, the head II can be quickly removed by a very simple operation for purposes of giving access to the interior of the well point for cleaning or repairing. Moreover, the recessing of the nuts 33 in the lower head ll enables the preservation of a uniform dimension of the well point from end to end so that there is a minimum resistance offered to the sinking of the well point into the soil, or withdrawal of the well point from the soil.

It is to be understood that the terms water" and air have been used herein in a general or broad sense. Obviously, the well point is not limited to the handling of water, as ,it is equally adaptable to use where other liquids may be present. Likewise, instead of air, the automatic control of the well point is equally adapted for excluding gases and other aeriform fluids.

While the specific details have been herein shown and described, the invention is not confined thereto, as changes and alterations may be made without departing from the spirit thereof as defined by the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is- 1. In a well point system, a header, a suction pump connected to said header, a plurality of well points connected to said header and extending into liquid-containing soil with their intakes disposed at different elevations but all within the vacuum influence range of the suction pump, and means within and forming a part of each well point for admitting liquid into the well point, but automatically excluding aeriform fluids therefrom.

2. In a well point system, a header, a suction pump connected to said header, a plurality of well points connected to said header and extending into liquid-containing soil with their intakes disposed at different elevations but all within the vacuum influence range of the suction pump, and means within and forming a part of each well point and independently operable responsive to the liquid level at the respective well points for After the water passes through the admitting liquid into the well point, but automatically excluding aeriform fluids therefrom.

3. In a well point, a body having a. jetting-andsuction passage extending axially therethrough at one side thereof, and also having a float chamber at the other side of said body in open communication with the exterior of said body and normally with the lower end of said jetting-andsuction passage,- means responsive to the passage of the jetting fluid through the well point for interrupting communication between the float chamber and lower end of the jetting-and-suction conduit whereby to prevent a jetting fluid from entering the float chamber during jetting action, and float valve means disposed in said float chamber and operable responsive to the liquid level therein for controlling communication between the jetting-and-suction passage and the exterior of the well point during suction action.

4. In a well point, an axially open tubular conduit flattened on one side and defining a jettingand-suction passage of generally D-shape crosssection within the same, an arcuate perforate wall member having its longitudinal edges secured to the conduit at the respective corners of its flattened side and forming a continuation of the arcuate side of the conduit, whereby to provide therewith a body of substantially circular cross-section, the perforate wall member aforesaid defining a float chamber within the same which is in open communication with the exterior of the body through its perforations, and having its lower end normally in open communication with the lower end of the jetting-and-suction passage, means for closing the upper end of the float chamber, means responsive to the passage of a jetting fluid through the well point for,

interrupting communication between the float chamber and the lower end of the jetting-andsuction passage whereby to prevent the jetting fluid from entering the float chamber during Jetting action, and float valve means disposed in said float chamber and operable responsive to the liquid level therein for controlling communication between the jetting-and-suction passage and the exterior of the well point through the float chamber during suction action.

5. In a well point, an axially open tubular conduit flattened on one side and defining a jettingand-suction passage of generally D-shape crosssection within the same, an arcuate perforate wall member having its longitudinal edges secured to the conduit at the respective corners of its flattened side and forming a continuation of the arcuate side of the conduit, whereby to provide therewith a body of substantially circular cross-section, the perforate wall member aforesaid defining a filtrate chamber within the same of substantially greater cross-sectional area than half the area of the circular well point body and which is in open communication with the exterior of the body through its perforations, and having its lower end normally in open communication with the lower end of thejetting-and-suction passage, means for closing the upper end of the float chamber, and means responsive to the passage of a jetting fluid through the well point for interrupting communication between the float chamber and the lower end of the jetting-andsuction passage whereby to prevent the jetting fluid from entering the float chamber.

6. In a well point, a tubular body of generally circular form having a partition extending thereacross dividing the same into a pair of axially parallel sections, one of which constitutes a jetting-and-suction passage, and the other consti tuting a float chamber, the exterior wall of the float chamber having perforations therein establishing communication withthe exterior of the well point, and the lower end of the float chamber being normally in'open communication with the lower end of the jetting-and-suction passage, means for closing the upper end of the float chamber, means responsive to the passage of a jetting fluid through the well point for interrupting communication betweenthe float chamber and the lower end of the jetting-and-suction passage whereby to prevent the jetting fluid from entering the float chamber during jetting action, and float valve means in said float chamber and operable responsive to the liquid level therein for controlling communication between the jetting-and-suction passage and the exterior of the well point through the float chamber during suction action.

7. In a well point, a tubular body of generally circular form having a partition extending thereacross dividing the same into a pair of axially parallel sections, one of which constitutes a jetting-andsuotion passage, and the other constituting a float chamber, the exterior wall of the float chamber having perforations therein establishing communication with the exterior of the well point, and the lower end of the float chamber being normally in open communication with the lower end of the jetting-and-suction passage, a foraminous screen encircling the tubu lar body so as to lie against the perforate wall of the float chamber, means for closing the upper end of the float chamber, means responsive to the passage of a jetting fiuid through the well point for interrupting communication between the float chamber and the lower end of the jettingand-suction passage whereby to prevent the jetting fluid from entering the float chamber during jetting action, and float valve means in said float chamber and operable responsive to the liquid level therein for controlling communication between the jetting-and-suction passage and the exterior of the well point through the float chamber during suction action.

8. In a wellpoint, a tubular body having a jetting-and-suction passage extending axially therethrough, and also having an axiallyopen float chamber in open communication laterally with the exterior of said body, means for closing the upper end of said float chamber, a plate positioned across the lower end of said tubular body and having an opening therethrough registering with the lower end of the jetting-andsuction passage, said plate also having a plurality of perforations therein registering with the lower end of the float chamber, a float valve disposed in said float chamber and cooperative with perforations in the plate aforesaid responsive to the liquid level in the float chamber, a tubular head secured to the lower end of the tubular body and having a chamber in its upper end for estab ng communication between the jettingand-suctionpassage and float chamber through the perforated plate, and a rigid disc valve disposed in said valve chamber and normally spaced from the plate but movable against the plate to close the perforations registering with thev float chamber responsive to the passage of ajetting fluid through the well point during jetting action.

9. In a well point, a tubular body having a jetting-and-suction passage extending axially therethrough, and also having an axially open float chamber in open communication laterally with the exterior of said body, means for closing the upper end of said float chamber, a plate of a relatively soft material positioned across the lower end of said tubular bodyand having an opening tberethrough registering with the lower chamber and cooperative with the perforations in the plate aforesaid responsive to the liquid level in the float chamber, a tubular head secured to the lower end of the tubular body so as to clamp the perforated plate aforesaid therebetween in sealed relation thereto, and having a chamber in its upper end for establishing communication between the jetting-and-suction passage and float chamber through the perforated plate, and a rigid disc valve disposed in said valve chamber and normally spaced from the plate but movable against the plate to close the perforations registering with the float chamber responsive to the passage of a jetting fluid through the well point during jetting action.

10. In a well point, a tubular body having a jetting-and-suction passage extending axially therethrough and also having an intake chamber therein in open communication with the exterior of said body, a tubular head detachably mounted on the lower end of said tubular body and coaxial therewith, said head having a valve chamber in the upper end thereof normally in open communication with the jetting-and-suction passage and also with the chamber in the body aforesaid, valve means in the valve chamber of the head operable responsive to the passage of a jetting fluid through the well point to interrupt communication between the chamber in the tubular body and the valve chamber, and removable fastening means recessed laterally in the. head and serving to detachably connect the head with the tubular body.

11. In a well point, a tubular body having a jetting-and-suction passage extending axially therethrough and also having an intake chamber therein in open communication with the exterior of said body, a tubular head detachably mounted on the lower end of said tubular body and coaxial therewith, said head having a valve chamber in the upper end thereof normally in open communication with the jetting and suction passage and also with the chamber in the body aforesaid, valve means in the valve chamber of the head operable responsive to the passage of a jetting fluid through the well point to interrupt communication between the chamber in the tubular body and the valve chamber, said head having an annular recess formed in the exterior wall thereof adjacent to its upper end, a plurality of studs can-led by the tubular body and extending axially through the head in spaced relation to each other at its margin, said studs having threaded extremities projecting into the annular recess aforesaid, and nuts threadedly received on the respective studs and disposed within the recess, said nuts cooperating with the studs to secure the head to the tubular body.

12. In a well point, a tubular body having a jetting-and-suction passage extending axially therethrough and also having an intake chamber therein in open communication with the exterior of said body, a plate mounted across the lower jetting-and-suction passage and also having a plurality of perforations registering with the chamber aforesaid, a tubular head detachably mounted on the lower end of said tubular body and coaxial therewith, said head having a valve chamber in the upper end thereof normally in open communication with the jetting-and-suction passage and also with the chamber in the body aforesaid through the opening and perforations respectively in the plate, a rigid disc valve mounted in the valve chamber of the head and axially movable towards and away from the perforations in the plate, and means disposed in said valve chamber for normally supporting the disc valve in spaced relation to the bottom of the chamber in the head and also normally spaced from the perforations in the plate, and for guiding said disc valve in its axial movement aforesaid, said valve disc being adapted to be automatically elevated in said valve chamber against the plate to close the perforations therein responsive to the passage of a jetting fluid through the well point, whereby to interrupt communication between the intake chamber in the tubular body and the valve chamber in the head.

13. Apparatus as defined in claim 12, wherein the spacing and guide means for the disc valve comprises laterally spaced bars disposed across the bottom of said valve chamber and turned upwardly at their ends so as to extend axially towards the bottom of the plate intermediate the opening which communicates with the jettingand-suction passage and the perforations which communicate with the intake chamber.

14. Apparatus as claimed in claim 10, in combination with a tubular head mounted on the upper end of said tubular body, and means at the bottom of said upper head for closing the upper end of said intake chamber in the tubular body.

15. Apparatus as claimed in claim 10, in combination with a tubular head mounted on the upper end of said tubular body, and means at extending across the upper end of the tubular body intermediate the same and the upper head, said plate having an opening therethrough registering with the jetting-and-suctlon passage, and means disposed within the upper head for guiding a fluid towards the opening in the plate as the fluid passes downwardly through the upper head to the tubular body.

16. Apparatus as claimed in claim 10, in combination with a tubular head mounted on the upper end of said tubular body, means at the bottom of said upper head for closing the upper end of said intake chamber in the tubular body, and a tubular foraminous fllter member encircling the tubular body intermediate the upper and lower heads.

1'7. Apparatus as claimed in claim 10, wherein the tubular head is provided with a second valve chamber in its lower extremity communicating with the upper valve chamber through an axial passage extending therebetween, a valve seat at the lower end of said axial passage, a floating ball-check valve mounted in the lower valve chamber and having a limited axial movement towards and away from the last mentioned valve seat, and means disposed within the second valve chamber for guiding said floating ball-check valve towards its seat.

18. An automatic well point of the class described, comprising a hollow body, an entrance and exit head mounted thereon and adapted to be connected to an entrance and exit conduit. said hollow body having a float chamber therein communicating with the exterior thereof in such manner that a liquid may enter therein with a relatively low velocity, fllter means mounted on the body to fllter the liquid as it enters the float chamber, said body also having a passage connecting the float chamber with the entrance and exit. head, a float disposed in said float chamber, and valve means operable by said float for controlling communication between the entrance and exit head and the float chamber through the connecting passage aforesaid.

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