US2164253A

US2164253A - Well point

Info

Publication number: US2164253A
Application number: US183551A
Authority: US
Inventors: Thomas F Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-01-05
Filing date: 1938-01-05
Publication date: 1939-06-27
Anticipated expiration: 1956-06-27

Description

T. F. MOORE June .27; 1939.

WELL POINT Filed Jan. 5, 1938 3 Sheets- Sheet 1 T. F. MOORE June 27, 1939.

WELL POINT Filed Jan. 5, 1938 3 Sheets-Sheet 2 Sitar/MK June 27, 1939. T. F.- MOORE 2,154,253

WELL POINT r Filed Jan. 5, 1938 3 Sheets-Sheet 3 Patented June 27, 1939 UNITED STATES PATENT OFFICE 21 Claims.

This invention appertains to the drainage or dewatering of soil, and more especially, to an improved well point which is adaptable to well point systems.

In the ordinary well point system, a number of well points are jetted or otherwise sunk in the ground to a suitable depth, and these well points are connected to one or more headers, according to the size of the area which is to be drained. 101 The headers in turn are connected to suitable pumping or suction apparatus which serves to draw the water or other fluid, as the case may be, from the soil. At times, impervious material, such as clay, will prevent the Water from reaching the well points, and this is more or less evidenced by the collection of pools of water at or near the surface of the ground. In such cases, it has been found in the past that these pools of Water may be taken care of by using what is 20. known as a water mop, which is nothing more than a short screen unit attached to one end of a suitable length of suction hose and having a shut-off valve therein to regulate the flow, the opposite end of the hose being attached to the 25 nearest header. By immersing the screen unit in the pools of water, the Water could be sucked into the header line in much the same manner as this is performed by the regular well points. However, it was found that these so-called Water 30. mops were not entirely satisfactory due to the fact that the screen unit frequently became blocked by floating leaves, chips and construction debris, and being partially exposed, they would sometimes freeze up around the intake in 35 cold weather. The most serious problem in connection with the use of these water mops involved the adjustment of the valves in the intake lines to prevent too much air from being sucked into the mop, and thence into the header lines. 40 If the water was drawn down very far, air would get into the header line and interfere with the working of the regular well points which were also attached to the same header line.

My present invention has to do with an im- 45 proved type of well point which has all the advantages of a regular well point, and which also can be used in place of the water mops formerly employed, but without the disadvantages of the old water mops in respect to the entrance of air. 50., The primary object of the invention, therefore, is to provide a well point which will admit water and other liquids up to its capacity, but which will automatically prevent air from entering into the same being drawn into the header 55.. lines.

A further object of the invention is to provide in a Well point, an automatically operable valve means for preventing the entrance of air into the well point, but permitting the free entrance of water into and through the well point.

Still another object of the invention is to provide in a well point a float valve which is operable responsive to the water level, whereby to permit the water to be freely admitted into the well point but which will automatically function to prevent air from being sucked into the same.

Another object of the invention is to provide a well point of novel construction, and which includes a central float chamber in which is mounted a float valve of a special and improved design, an annular suction and jetting passage surrounding the float chamber, and means for establishing and interrupting communication between the annular passage and the float chamber responsive to the water level in the float chamber. 2

Other and further objects and advantages of the invention will be hereinafter described, and the novel features thereof defined by the appended claims.

In the drawings:

Figure 1 is a view in side elevation of my improved well point, the same being connected to an extension pipe having suitable fittings for connecting the well to a header line:

Figure 2 is a vertical sectional view taken through the well point and showing particularly the construction of the float valve which is mounted in the central float chamber;

Figure 3 is a vertical sectional view, generally similar to Figure 2, but taken in a plane displaced somewhat from the plane of the section of Figure 2;

Figure 4 is a top plan view of the well point shown in Figures 2 and 3;

Figure 5 is a fragmentary vertical sectional view illustrating the action of the float valve in preventing the entrance of air into the well point, said float valve being shown in engagement with the bottom of the float chamber and closing the ports therein, as distinguished from the open position shown in Figures 2 and 3;

Figures 6, '7, 8 and 9 are horizontal sectional views taken respectively on the lines 66, '|1, 8--8 and 9-9 of Figure 3;

Figure 10 is a top plan view of the resilient pressure member which coacts with the float valve to insure effective seating of the float valve on the bottom of the float chamber when the valve comes into engagement with the same; 55

Figure 11 is a view in side elevation of the pressure member shown in Figure 10; and

Figure 12 is a plan view of a blank of flexible material, preferably sheet rubber, which forms the float valve shown in the assembly views (Figures 2, 3 and 5).

Like reference characters designate corresponding parts in the several figures of the drawings.

As seen in Figure 1, I designates generally my improved well point, which is preferably of unitary construction. The upper end of the well point unit is connected to a conduit or pipe 2 having suitable connections and couplings, generally designated 3, for connecting the same to a header line (not shown) which forms a part of a regular well point system, as will be readily understood by those versed in the art. The well point is preferably so constructed as to enable the same to be jetted into the ground, or it may be otherwisesunk if preferred.

Referring more particularly to Figures 2 and 3, 4 designates the upper head of the well point, this head preferably having the form of an internally threaded coupling for facilitating connection of the same to the lower end of the pipe 2 shown in Figure 1, which serves to convey the jetting fluid to the well point during the jetting operation, and also to convey the drainage fluid from the well point to the main header line or lines during thesuction operation. Suitably secured to the bottom of the upper head 4, as by welding, is a pipe 5 which extends downwardly below the head 4 for a distance, and to the outer surface of this pipe 5 a plurality of ribs or bars 6 are secured, as by welding. These ribs or bars 6 are arranged in circumferentially spaced relation to each other about the periphery of the pipe 5, and run lengthwise of the same, and constitute spacing means for spacing a foraminous filter screen I from the outer surface of the pipe 5. The filter screen I is preferably composed of wire mesh and is tubular in form so as to surround all of the bars 6 and the pipe 5 in spaced relation to the latter. The upper end of the filter screen 'I is secured to the lower end of the upper head 4, as by welding or soldering the same thereto, and in order to maintain a substantially uniform diameter of the well point unit from end to end, the lower end of the head 4 is preferably provided with an annular recess 8, into which the upper end of the filter screen I is adapted to be received. The recess 8 also affords a more effective anchoring of the filter screen I to the head 4. The lower end of the filter screen I is similarly anchored to a lower head or shell 9, which is coaxial with the upper head 4 and also preferably provided with an annular recess III around its upper end for receiving the lower end of the filter screen. The lower end of the pipe 5 is suitably welded or otherwise secured to the lower head 9, thereby forming a substantially rigid unit composed of axially spaced upper end lower heads 4 and 9, the pipe 5, the annularly spaced filter screen l and the additional parts hereinafter described.

Mounted within the pipe 5 and coaxially positioned relatively thereto is a second pipe I I, defining an annular space I2 therebetween. The lower extremity of the inner pipe II is secured to the lower head 9, as by welding, and the upper end thereof is closed by a cap or cover plate IS. The inner face of the cap I3 is preferably provided with an annular recess I4 to receive the upper extremity of the pipe I I, and thereby maintain the upper end of the pipe water and air tight. The space within the pipe II and below the cap I3 constitutes a chamber I5, hereinafter referred to as a float chamber. The cover plate or cap I3 is preferably provided with a plurality of radially extending lugs or arms l5, formed integrally therewith, and the undersides of these arms are recessed, as at IT, adjacent to their outer extremities for receiving the upper extremity of the outer pipe 5, thus aiding to preserve a positive spacing of the two pipes at their upper ends. The annular space I2 between the two pipes 5 and I I is thus in constantly open com munication in an upward direction with the interior of the upper head 4, as will be best understood from reference to Figures 2, 3 and 4, such communication being established by reason of the spacing of the bosses or lugs I6 formed on the cap or cover plate I3.

Each lug is provided with an aperture for receiving a tie bolt I 8, the tie bolts extending downwardly through the lugs I6 and through the annular space I2 between the pipes 5 and II. The lower head 9 is provided with a plurality of upstanding lugs or bosses I9, these latter lugs corresponding in number to the number of tie bolts I8. The lugs I9 extend upwardly into the lower end of the annular space I2 between the pipes 5 and II, and are adapted to fit snugly between these pipes, as by forming their inner and outer faces to correspond with the curvatures of the respective inner and outer pipes. The upper extremities of the lugs I9 are apertured and tapped to receive the lower threaded extremities 20 of the tie bolts I8. Thus the tie bolts I'I serve to secure the cap I3 tightly and rigidly in position on the upper ends of the pipes 5 and II, and also contribute to the maintenance of a rigid assembly of the pipes with the lower head.

The outer pipe 5 is provided adjacent its lower end with a plurality of circumferentially spaced apertures 2I, which are adapted to register with corresponding apertures 22 formed in the upstanding lugs or bosses I9 on the lower head 9, and these two sets of apertures are also adapted to register with corresponding apertures 23 formed in corresponding circumferentially spaced relation in the lower end of the inner pipe II. As best seen in Figures 2, 3 and 5, the lower extremities of the spacer rods or bars 6 are cut on a diagonal, as at 24, so as to establish free communication between the annular space formed between the foraminous filter screen I and the outer pipe 5, (which is divided up by the spacer rods or bars 6 into a plurality of separate passages, as will be best understood from reference to Figures 6 and '7), with the lower end of the float chamber I5 through the registering

apertures

2I, 22 and 23 in the outer pipe 5, the lugs I9 and the inner pipe II, respectively. Thus the water which is to be drained from the soil into which the well point is sunk or in which the well point is submerged, will pass inwardly through the foraminous filter screen into the annular space between the filter screen and the outer pipe 5, thereupon flowing downwardly through this space between the spacer rods or bars 6, and finally entering into the lower end of the float chamber I5 through the registering

apertures

2I, 22 and 23. From the float chamber I5, the filtrate or drainage water passes downwardly through the upper end 25 of the lower head 9, which is provided with a plurality of perforations or apertures 26 communicating at their upper ends with the lower end of the float chamber |5, andat their lower ends with a chamber 21 formed within the lower head 9 at the opposite side of the end 25 of the head. This chamber 21 communicates with the annular space l2 between the pipes 5 and II through passages 28 formed in the upper end 25 of the lower head 9 and. lying between the upstanding bosses I9, as will be best understood from reference to Figures 3 and 8. Accordingly, the water may be drawn from the chamber 21 upwardly through the annular space |2 to the upper end of the well point, from which it may be conducted upwardly through the pipe 2 which is connected to the upper well point head 4.

Mounted in the float chamber I5 is a float body 29 of any suitable construction. As shown, the float body 29 is composed of a cylindrical shell 39 having its opposite ends sealed by suitable plugs 3| and 32, the same being somewhat smaller than the inner pipe I I so as to be freely movable axially within the float chamber I5. 33 designates a bolt passing axially through the float body 29 and having nuts 34 and 35 threadedly received on its opposite extremities to maintain the plugs 3| and 32 tight in the opposite ends of the cylindrical shell 30. It is to be understood that I do not wish to be limited to the construction of the float body as just described, as the same may be modified at will. For example, the float body may be composed of a solid body of cork, wood, or an equivalent material which will float, or it may be composed of some suitable heavier material of hollow form to give it the floatable characteristic.

Secured to the lower end of the bolt 22 which extends through the float body 29, is a flexible valve member, generally designated 36. The construction of this valve member will be best understood from reference to Figure 12, and as shown in this figure, the valve member is preferably composed of relatively thin sheet rubber which may be stamped out or otherwise cut in the form of a substantially circular central disc or diaphragm 31, having a plurality of integral flaps or arms 38 projecting radially therefrom at circumferentially spaced intervals. In mounting the valve member 36 upon the lower end of the bolt 33, the arms 36 formed around the disc 31 are folded upwardly for common attachment to the end of the bolt 33, as by overlapping the outer extremities of the arms one upon the other and extending the bolt 33 through the overlapped ends of the arms 38, in which event, the same may be clamped between the nut 35 and a clamping nut 39, the latter being applied to the lower extremity of the bolt 33. Instead of overlapping the arms 38 as just described, the same may be suitably secured to a central connecting member, and this connecting member may be clamped intermediate the nuts 35 and 39 in an obvious manner. In either case, the central flexible disc or diaphragm 31 of the valve member 36 is freely and yieldingly suspended from the bolt 33, or in other words, from the float body 29, preferably on the central axis of the float body, and the disc 31 is capable of moving relatively towards and away from the lower end of the float body.

Now so long as there is suflicient water in the float chamber l5 to substantially raise the float body towards the upper end of the float chamber, the rubber disc or diaphragm 31 will be elevated above the perforations 26 in the upper end 25 of the lower head 9 of the well point, as shown in Figures 2 and 3. As illustrated in these views, the disc or diaphragm 31 will assume a more or less concavo-convex shape under the conditions just described, by reason of its flexible suspension through means of the arms 38 which serve to attach the disc 31 to the lower end of the float body 29.

Assuming that there is insuificient water passing into the float chamber |5, to substantially float the body 29, or if the water level should be drawn down substantially below that in the condition represented in Figures 2 and 3, then the float body 29 will automatically move downwardly in the float chamber l5 and bring the rubber disc or diaphragm 3'! into engagement with the upper end 25 of the head 9, thereby closing off the perforations 26. This condition is represented in Figure 5. In order to effectively seat the disc or diaphragm 31 on the upper end 25 of the head 9, and to insure an effective blocking of the perforations or apertures 26, I preferably provide a resilient pressure member, generally designated 49, which is mounted intermediate the rubber valve member 36 and the float body 29. The construction of this pressure member will be best understood from reference to Figures 10 and 11, wherein the same is represented as a resilient sheet metal stamping having radially projecting arms 4| which are curved downwardly in the direction of their lengths. The arms 4| of the pressure member 40 are adapted to overlie and bear upon the arms 38 of the valve member 36, and their action will be readily understood from reference to Figure 5. If the water should subsequently rise in the float chamber |5 after the float body 29 and valve member 36 have assumed the condition shown in Figure 5, the float body 29 will be floated upwardly in the float chamber and will raise the valve member 36 off of the upper end of the lower head 9 and thereby uncover the apertures or perforations 26. In such a case, and as the flexible valve member 36 is lifted, the central disc or diaphragm 31 will be progressively raised from the outer marginal edge of the disc 31 towards the center of the disc. This action may therefore be said to be in the nature of a stripping or peeling of the disc or diaphragm 31 off of the end 25 of the head 9, and I have found that the action is particularly effective and efficient inasmuch as it requires a less head of water to lift the valve member 36 than if the valve were suspended from the float body 29 at a point or points on or near the circumference of the float body. Also the valve construction herein shown and described is much more efficient and more easily unseated than a rigid disc valve suspended from the float body at the center of the valve or otherwise, for the reasons already given.

When the valve member 36 is seated on the upper end 25 of the lower head 9 so as to close off the perforations or apertures 26, it will be obvious that air cannot enter the well point beyond this valve, and hence no air can be sucked up through the well point. On the other hand, if the water level is such that there is no tendency for air to enter the well point, the float valve will automatically permit the well point to function in the regular manner. It will thus be understood that the float valve automatically functions responsive to the water level in the float chamber l5, and hence the admission of water through the well point and the exclusion of air therefrom during the suction action, is likewise automatically responsive to the water level in the float chamber l5.

To prevent the float chamber Hi from becoming air bound, and which, if permitted would interfere with the operation of the float valve in the manner hereinbefore described, I preferably provide a vent 42 which extends through both of the pipes and II, preferably adjacent to the upper ends thereof. The inner end of the vent 42 terminates flush with the inner surface of the pipe I I so as not to interfere with the movement of the float body 29 in the float chamber I5. The outer end of the vent 42 is preferably extended beyond the outer surface of the pipe 5 and terminates slightly short of the inner surface of the foraminous filter screen 1. The function of this vent 42 will be readily apparent from the foregoing, and for this reason, need not be further described.

As hereinbefore mentioned, my improved well point preferably provides for the sinking of the same into the soil by the well known jetting operation. Reference will now be made to those elements which contribute to this end.

Mounted in the lower head 9 is a pilot tip 43, having its lower edge serrated to form teeth 44 which may be utilized to grind away or loosen the soil, as by rotating or oscillating the well point as it is being sunk. This pilot tip fits snugly in the head 9 and is secured thereto by the rivet 45 which extends through the head 9. The upper end 46 of the pilot tip 43 is spaced from the upper end of the head 9 and forms the bottom side of the chamber 21 previously referred to. The end 46 is provided with an opening or passage 41 which is normally closed by a ball float valve 48, the latter being interposed between the upper end 46 of the pilot tip 43 and the rivet 45. The arrangement of the passage 41, the ball float valve 48 and the rivet 45 preferably corresponds to that disclosed in my prior Patent No. 2,100,145, dated November 23, 1937. In other words, I preferably position the rivet 45 somewhat off center respecting the diameter of the head 9 so that there will be a greater space at one side of the rivet than at the other between the rivet and the interior wall of the pilot tip 43. Of course, the rivet 45 is spaced far enough below the upper end 46 of the pilot tip 43 so as to permit the ball valve 48 to freely move towards and away from the lower end of the passage 41. During the suction operation of the well point system, when the water is sucked into the well point from the soil, the ball float valve 48 will normally assume the position shown in full lines in Figures 2 and 3, wherein this valve is seated in the lower end of the passage 41 to close this passage and, thus prevent sand, stones, gravel, and water which contains considerable solids, from being sucked up into the well point. On the other hand, during the jetting operation, the force of the jetting fluid as it passes downwardly through the well point will unseat the ball valve 48 and force it downwardly into the larger pocket at one side of the rivet 45, as shown in broken lines in Figure 2.

In order to prevent the jetting fluid from escaping from the well point through the filter screen 1 during the jetting operation, I provide a valve 49, preferably comprising a rigid circular metal disc, this valve being mounted in the chamber 21, and being free to move towards and away from the upper end 25 of the lower head 9. Extending upwardly from the upper end 46 of the pilot tip 43, and disposed radially at spaced intervals about the axis of the passage 41, there is provided a plurality of webs 50. The upper ends of these webs abut against the lower side of the upper end 25 of the head 9, and are cut out to form ledges 5|, upon which the disc valve 49 is adapted to seat, as shown in full lines in Figure 2, 3, and 5. Thus the disc valve 49 is normally supported in spaced relation to the lower ends of the apertures or perforations 26 in the upper end 25 of the head 9, and in spaced relation to the passage 41, and rests upon the ledges 5|. This position of the valve 49 is maintained during the suction operation so that the drainage fluid is permitted to be drawn into and upwardly through the well point. On the other hand, during the jetting operation, the jetting fluid acts upon the disc valve 49 to automatically lift the same upwardly to the dotted line position shown in Figures 2 and 3, thereby causing the valve to seat against the lower side of the upper end 25 of the head 9, and closing off the perforations or apertures 26. This action of the valve 49 generally corresponds to the action of the ring valve disclosed in my prior patent hereinbefore referred to, and prevents the jetting water from backing up through the perforations 26 into the float chamber l5 and outwardly from the float chamber through the

openings

23, 22, 2| and out through the filter screen 1. As the jetting water enters the cham ber 21, a preponderance of the jetting water will pass under the disc valve 49 by reason of its normally spaced position above the passage 41, and the jetting water then flows down through the passage 41, displacing the ball valve 48 downwardly, and continues its flow downwardly through the lower end of the well point from which it is ultimately discharged to serve the purpose of eroding the soil beneath the well point so that the well point can be sunk to the desired depth. As the jetting water acts against the underlying soil, it reacts upon the disc valve 49 to lift the same upwardly off of the ledges 5| and into engagement with the lower face of the upper end 25 of the head 9, thereby closing the perforations 26 and maintaining the same closed so long as the jetting action continues. Accordingly, the full force of the jetting water is utilized to displace the soil below the well point, and there is no objectionable back waste permitted through the filter screen 1. By reason of the elimination of the back waste, the jetted hole is washed out more thoroughly and the well point can be sunk'in the ground to its full length much more rapidly and with greater ease. As

soon as the jetting action is discontinued, the

disc valve 49 automatically drops downwardly away from the perforations 26 onto the ledges 5| of the webs 50, thereby immediately conditioning the well point for the performance of the suction operation in draining or dewatering the soil.

Operation Having describedin detail the construction of my improved well point, the operation thereof Will be briefly summarized as follows: When the well point unit has been assembled as shown in Figure 1, it is ready to be sunk in the ground, this sinking action being preferably performed by the usual jetting operation. In such a case, the coupling 3 is connected to a suitable source of supply of jetting water, and the jetting water is forced downwardly through the pipe 2 and through the well point unit I under a relatively high pressure. The jetting fluid enters the upper end of the well point and passes between from the cap or cover plate I3, into the upper end of the annular space If formed between the coaxial pipes and H. The flow continues downwardly through the space 12, the lower end of which is in open communication with the chamber 21 in the lower head 9 through the passages 28, and as the jetting fluid enters this chamber and continues its downward flow through the passage ll, it displaces the ball float valve 49 to the broken line position shown in Figure 2 and positively holds the ball at rest in the pocket between the offset rivet 45 and the inner face of the pilot tip 43. By reason of the offset position of the rivet 45, the ball valve 48 will have no tendency to oscillate or bounce up and down between the rivet and the upper ball seat. With the ball valve in the broken line position shown in Figure 2, the jetting water passes freely by the ball valve and out through the lower end of the pilot tip 33 with its force substantially undiminished and concentrated upon the underlying soil, thereby eifectively and expeditiously eroding the soil and causing the well point to sink down into the soil. As the soil is eroded below the well point, the jetting water reacts upon the disc valve 49 in the chamber 21, causing the same to be lifted up to the broken line position illustrated in Figures 2 and. 3, thereby closing the perforations 26 and positively and effectively preventing back waste through the foraminous filter screen I. If desired, the well point may be rotated or oscillated to cause the teeth 44 on the lower extremity of the pilot tip 43 to loosen the underlying soil and thereby facilitate the sinking of the well point.

When the well point has been sunk to the desired depth, the coupling 3 may then be connected to a suitable pump or suction apparatus for causing the fluid in the soil to be drawn intothe well point and upwardly therethrough where it can be conveyed to and discharged at any convenient point. In draining a large area, a proportionate number of well points may be sunk at different points in and/or around the area and all of the well points may be connected to one or more main header lines to which the pumping apparatus may be connected.

During the suction or drainage operation, the drainage fluid passes inwardly through the foraminous filter screen I and follows a path through the well point, as indicated by the arrows in Figure 2. As shown by the arrows, the fluid passes downwardly through the annular space between the filter screen l and the outer pipe 5, constituting a filtrate chamber, which is subdivided into a plurality of filtrate passages by the spacer bars 6 which serve to maintain the filter screen 1 in spaced relation to the pipe 5. At the lower end of this annular space above referred to, the fluid flows radially inwardly through the registered openings 2|, 22 and 23 in the pipe 5, lugs 59 and inner pipe II, respectively, thereby entering the float chamber i5 and causing the float body 29 to rise in the float chamber and lift the float valve 36 upwardly, as shown in Figures 2 and 3. Thus the fluid is permitted to pass downwardly through the perforations or apertures 26 in the upper end 25 of the lower head 9, and into the chamber 21 in the upper end of the head 9. From the chamber 21, the fluid passes upwardly through the ports 28 in the upper end 25 of thehead 9, and thence continues upwardly through the annular space [2 between the pipes 5 and II and emerges from the upper end of this space between the lugs IS on the cap l3, into the upper head 4, which is connected to the lower end of the extension pipe or conduit 2, and through which the fluid may be drawn upwardly to the surface and into the main header lines. Thus it will be seen that the annular space I2 constitutes a common jetting and suction passage in the well point.

Now if the level of the drainage fluid in the soil should be drawn down substantially to the bottom of the well point, or if for any reason the flow of the water into the well point should diminish to such an extent as to tend to cause air to be sucked into the well point, the float valve 36 will automatically function to exclude the air, it being understood that the float valve is operable responsive to the rise and fall of the fluid level in the inner float chamber I 5. In other words, when the water level in the float chamber I5 falls, the float body 29 moves downwardly in the float chamber, bringing the flexible sheet rubber disc 31 into seating engagement on the upper end 25 of the lower head 9, thereby closing off the perforations 26. The valve 36 is held tightly against its seat at the bottom of the float chamber by the weight of the float body 29, and the resilient fingers or arms 4! of the pressure member 40 will press the valve down evenly through engagement of these fingers with the flexible flngers or arms 38 of the valve 33, thereby assuring substantially even contact of the disc 3? over the perforations 26 so that no air can pass by the valve and through the perforations 23. The pressure member 40 further contributes to the preservation of the shape of the valve 36, which, in its suspended position as shown in Figures 2 and 3, is more or less concavo-convex. Upon resumption of a condition under which the fluid in the soil is present in sufficient quantities to justify further withdrawal of the fluid from the soil, the fluid will rise in the float chamber l5 and automatically lift the float body 29 upwardly. As the float body 29 rises, the flexible valve 36 will be yieldingly and progressively lifted from its outer margin towards the center of the disc 37, resulting in substantially a peeling of the disc 31 from its seat on the upper perforated end 25 of the head 9. As soon as the valve 36 has been elevated sufficiently far to uncover the perforations 26, the fluid in the float chamber I5 is permitted to flow downwardly through the perforations 23 into the chamber 21, and thence upwardly through the ports 28 in the upper end 25 of the head 9, between the lugs I9, and then up, through the annular space I2 between the pipes 5 and II, finally emerging through the space between the lugs 16 on the upper cap I3, and passing into the extension pipe 2 which is connected to the upper head 4.

It will thus 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 up through the well point. It will likewise be readily understood that the well point is quite simple in construction yet quite rugged, all without any sacrifice of efficiency of operation as compared with other well points of the same or comparable size. By reason of its substantially uniform dimension from end to end, there is a minimum resistance offered to the sinking of the well point into the soil, or the withdrawal of the same therefrom, and the sinking of the well point is made much easier by reason of the elimination of back waste of the jetting fluid.

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, a tubular body adapted to be sunk in fluid-containing soil for withdrawing the liquid therefrom, said tubular body including a foraminous filter screen, a pipe disposed within the screen and radially spaced relatively thereto and defining a liquid inlet passage around the outside of the pipe and a liquid outlet passage within the pipe, said inlet and outlet passages normally being in open communication with each other, whereby to permit the liquid in the soil to freely pass therethrough, and means within the pipe for preventing air from entering the outlet passage when the liquid in the soil falls below a certain level or is present in an insufficient quantity to completely fill said passages.

2. In a Well point, a tubular body adapted to be sunk in fluid-containing soil for withdrawing the liquid therefrom, said tubular body including a foraminous filter screen, a pipe disposed within the screen and radially spaced relatively thereto and defining a liquid inlet passage around the outside of the pipe and a liquid outlet passage within the pipe, said inlet and outlet passages normally being in open communication with each other, whereby to permit the liquid in the soil to freely pass therethrough, and means responsive to the liquid level within the pipe for preventing air from entering the outlet passage when the liquid in the soil falls below a certain level or is present in an insuflicient quantity to completely fill said passages.

3. In a well point, a tubular body adapted to be sunk in fluid-containing soil for withdrawing the liquid therefrom, said tubular body including a foraminous filter screen, a pipe disposed within the screen and radially spaced relatively thereto and defining a liquid inlet passage'around the outside of the pipe and a liquid outlet passage within the pipe, said inlet and outlet passages normally being in open communication with each other, whereby to permit the liquid in the soil to freely pass therethrough, a chamber interposed between the inlet and outlet passages aforesaid and communicating therewith, and valve means in the chamber and operable by the liquid level therein for interrupting communication between said passages and preventing air from entering the outlet passage when the liquid in the soil falls below a certain level or is present in an insufficient quantity to completely fill said passages.

4. In a device for draining fluid-containing soil, a body having a screened inlet passage and. an outlet passage, said outlet passage being adapted to be connected to a means for producing suction therein and being normally in open communication with the inlet passage, and means enclosed within the communication passages for preventing air from entering the outlet passage when the liquid in the soil falls below a certain level or is present in an insuflicient quantity to completely fill said passages.

5. In a device for draining fluid-containing soil, a tubular body having a screened inlet passage and an outlet passage, said outlet passage being adapted to be connected to means for producing suction therein and being normally in open communication with the inlet passage, and

float valve means within the communicating passages and operable responsive to liquid withdrawn from the soil for preventing air from entering the outlet passage when the liquid in the soil falls below a certain level or is present in an insufficient quantity to completely fill said passages.

6. In a well point, coaxial tubular members disposed one within the other and defining an annular passage therebetween, a screen surrounding said outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, said filtrate chamber being normally in open communication with the lower end of the annular passage aforesaid through passages extending through both tubular members adjacent to the lower end thereof and across the annular passage and opening into the interior of the inner tubular member, and means for closing the upper end of said inner tubular member.

'7. In a well point, coaxial tubular members disposed one within the other and defining an annular passage therebetween, a screen surrounding said outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, said filtrate chamber being normally in open communication with the lower end of the annular passage aforesaid through passages extending through both tubular members adjacent to the lower end thereof and across the annular passage and opening into the interior of the inner tubular member, means for closing the upper end of said inner tubular member, whereby to form an inner chamber, and means operable responsive to the fluid level in said chamber for automatically controlling the flow of fluid through the well point when the well point is connected to a means for producing suction therein.

8. In a well point, coaxial tubular members disposed one Within the other and defining an annular passage therebetween, a screen surrounding said outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, said filtrate chamber being normally in open communication with the lower end of the annular passage aforesaid through passages extending through both tubular members adjacent to the lower end thereof and across the annular passage and opening into the interior of the inner tubular member, means for closing the upper end of said inner tubular member, whereby to form an inner chamber, a valve seat disposed at the bottom of said chamber, and float valve means disposed in said chamber in 'coactive relation to said valve seat and operable responsive to the fluid level in said chamber for automatically controlling the flow of fluid through the well point when the well point is connected to a means for producing suction therein.

9. In a well point, coaxial tubular members disposed one within the other and defining an annular passage therebetween, a screen surrounding said outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, said filtrate chamber being normally in open communication with the lower end of the annular passage aforesaid through passages extending through both tubular members adjacent to the lower end thereof and across the annular passage and opening into the interior of the inner tubular member, means for closing the upper end of said inner tubular member, whereby to form an inner chamber, a valve seat disposed at the bottom of said chamber, float valve means disposed in said chamber and operable responsive to the fluid level in said chamber for automatically controlling the flow of fluid through the well point when the well point is connected to a means for producing suction therein, said float valve means comprising a float body disposed in said inner chamber and freely movable axially therein, and a flexible valve member carriedby said float body and cooperative with said valve seat.

10. Apparatus as claimed in claim 9, wherein the valve member is yieldably suspended from the lower extremity of the float body.

11. Apparatus as defined in claim 9, wherein the valve member comprises a flexible disc having a plurality of arms extending radially from the margin thereof at spaced points, and the arms being folded upwardly and inwardly towards the center of the disc and secured to the float body.

12. Apparatus as defined in claim 9, wherein the valve member comprises a flexible disc having a plurality of arms extending radially from the margin thereof at spaced points, and the arms being folded upwardly and inwardly towards the centerof the disc and secured to the float body substantially at the central axis of the inner chamber and float body.

13. In a well point, coaxial tubular members disposed one within the other and defining an annular passage therebetween, a screen surrounding said outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, said filtrate chamber being normally in open communication with the lower end of the annular passage aforesaid through passages extending through both tubular members adjacent to the lower end thereof and across the annular passage and opening into the interior of the inner tubular member, means for closing the upper end of said inner tubular member, whereby to form an inner chamber, float valve means disposed in said chamber and operable responsive to the fluid level in said chamber for automatically controlling the flow of fluid through the well point when the well point is connected to a means for producing suction therein, a tubular head secured to the lower extremities of said coaxial tubular members and screen, the upper end of said head having a wall extending across the lower ends of the inner chamber formed by the inner tubular member and also across the annular passage defined between the inner and outer tubular members, the portion of the wall aforesaid which lies below the inner chamber being perforated and constituting a seat for the float valve means, and the portion of the wall which lies below the annular passage between the coaxial tubular members being provided with a passage establishing communication between the annular passage aforesaid and the interior of the head.

14. Apparatus as claimed in claim 13, wherein the tubular head is provided with a plurality of annularly spaced lugs projecting above the end wall of the head and interposed between the lower ends of the coaxial tubular members and fitting tightly therebetween, said lugs having apertures therein forming portions of the passages which establish communication between the filtrate chamber and the interior of the inner tubular member.

15. Apparatus as claimed in claim 13, in combination with valve means mounted within the tubular head and cooperable with the perforated portion of the end wall thereof whereby to close said perforations responsive to the flow of a jetting fluid through the well point.

16. Apparatus as claimed in claim 13, in combination with valve means mounted within the tubular head and cooperable with the perforated portion of the end wall thereof whereby to close said perforations responsive to the flow of a jetting fluid through the well point, said valve means comprising a rigid imperforate disc,

17. Apparatus as claimed in claim 13, in combination with valve means mounted within the tubular head and cooperable with the perforated portion of the end wall thereof whereby to close said perforations responsive to the flow of a jetting fluid through the well point, and means for normally supporting the last mentioned valve means in spaced relation to the perforated end wall of the head with the valve means freely movable axially intermediate said supporting means and the end wall, and said supporting means being so constructed as to permit the jetting fluid to freely flow past the same and out through the lower end of the head so as to create a reaction upon the valve means to lift the same into engagement with the perforated end wall and thereby close the perforations during the jetting action,

18. Apparatus as claimed in claim 13, in combination with valve means mounted within the tubular head and cooperable with the porforated portion of the end wall thereof whereby to close said perforations responsive to the flow of a jetting fluid through the well point, and float valve means mounted within the head and cooperable with a seat having an axial passage therethrough within the head, said last mentioned float valve means normally engaging the seat to close the axial passage aforesaid, but being displaceable from the seat responsive to the flow of the jetting fluid through the well point.

19. In a well point, axially spaced tubular heads, coaxial tubular members disposed one within the other having their opposite ends secured to the respective heads and defining therebetween an annular jetting-and-suction passage, a screen surrounding the outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, the opposite ends of said screen being secured to the respective heads, one of said heads having a wall at one end thereof extending across the lower extremities of said coaxial tubular members, the central portion of said end wall being perforated for establishing communication between the space within the inner tubular member and the space within the head, and said end wall also having annularly spaced passages therethrough registering with the jetting-and-suction passage, and a plurality of lugs disposed intermediate the annularly spaced passages and fitting snugly between the coaxial tubular members, said coaxial tubular members and lugs having registering apertures therein for establishing communication between the filtrate chamber and the space within the inner tubular member, closure means disposed on the end of the inner tubular member opposite to the head having the perforated end wall and defining an inner chamber, said closure means having circumferentially spaced lugs extending radially therefrom and into engagement with the corresponding end of the outer tubular member, tie bolts extending through the closure lugs and the annular jettingand-suction passage and secured to the head lugs which are disposed between the coaxial tubular members, float valve means mounted in the inner chamber and movable towards and away from the perforated head wall responsive to the fluid level in said float chamber, whereby to prevent air from being drawn through the well point during the suction action, and valve means mounted within the head having the perforated end wall, and at the opposite side of the end wall from the float valve means for preventing back waste during the jetting operation, said last mentioned valve means being normally supported within the head having the perforated end wall in spaced relation to the end wall, and being movable into engagement with the end wall to close the perforations by the reaction of the jetting fluid during the jetting operation.

20. In a well point, coaxial tubular members disposed one within the other and defining an annular passage therebetween, a screen surrounding said outer tubular member in radially spaced relation thereto and defining therebetween a filtrate chamber, said filtrate chamber being normally in open communication with the lower end of the annular passage aforesaid through passages extending through both tubular members adjacent to the lower end thereof and across the annular passage and opening into the interior of the inner tubular member, means for closing the upper end of said inner tubular member, whereby to form an inner chamber, means operable responsive to the fluid level in said chamber for automatically controlling the flow of fluid through the well point when the well point is connected to a means for producing suction therein, and means for venting said inner chamber,

21. In a well point, a body having a jettingand-suction passage extending axially therethrough, and also having a float chamber in open communication with the exterior of said body and normally with the lower end of said jettingand-suction passage, means responsive. to the passage of a jetting fluid through the wellpoint for interrupting communication between the float chamber and 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 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.

THOMAS F. MOORE.