US2083389A - Well point - Google Patents

Description

T. F. MOORE June `8, 193 7.

WELL POINT Filed May 7, 1956 in the production of the castings.

Patented June 8, 1937 UNITED STATES ATE-NT OFFICE 4 Claims.

This invention relates to well, points, and more particularly, to those types of well points which are adapted to produce a jetting action on the soil into which the well points are to be sunk, following which the Well points are utilimd for drawing off seepage or drainage fluids in the soil through a suction action.

The primary object of th-e present invention is to provide a well point construction of such a character as to be readily and easily fabricated or assembled, and which particularly lends itself to manufacture as a welded assembly or unit.

A further object of the invention is to provide a well point construction in which the various parts are of more simpley design, and hence less expensive in manufacturing cost. In other words, it has been my aim to reduce, as much as possible, expensive machining operations in the fabrication of the well point, and eliminate intricate castings, such as have heretofore been employed. It has been found from actual experience that imperfections frequently occurred in these intricate castings formerly employed, even though considerable care and skill was exercised The elimination of such castings and the attendant objections thereto in respect to their structural deciencies and the high cost of manufacture is of considerable advantage in the production of an inexpensive well point.

A still further object of the invention is to provide a well point having a direct unobstructed axial passage therethrough for the jetting fluid through the entire well point from top to bottom thereof, together with an improved valve assembly adapted to automatically control the jetting and drainage or suction actions.

Another object of the invention is to provide in a well point of the character hereinbefore referred to, an improved filtrate chamber construction from which the seepage or drainage fluid is directed into an unobstructed axial passage through the well point to permit the fluid to be with-drawn by suction, said ltrate chamber having a plurality of passages establishing communication between the same and the axial passage through the well point, and these communicating passages being formed by radially spaced concentric tubes or pipes, the lower ends of which terminate in the same plane and constitute a seat for a ring valve, the latter being adapted to automatically control the opening and closing of said communicating passages, according to whether the suction or letting operations are being performed.

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

In the drawingz- ,l Figure lis a side elevation, partly broken away, of a well point embodying the essential features of my invention; s

Figure 2 is an enlarged longitudinal sectional view, partly broken away, of thesame well point, taken approximately on line 2-2 of Figure 1; lo

Figure 3 is a transverse sectional view taken approximately on line 3-3 of Figure 2;

Figure 4 is a transverse sectional view taken approximately on the line 4-4 of Figure 2; and

Figure` 5 is a transverse sectional view taken 15 approximately on the line 5-5 of Figure 2.

Like reference characters designate corresponding parts in the several figures of the drawingwherein the well point is illustrated as being of cylindrical or tubular form of any suitable i210 length, and having a substantially uniform external diameter from end to end to enable it .to `be sunk endwise into the soil, so that when brought to the required depth, the iiuid in the soil may be withdrawn through the well point by 25 some suitable suction device (not shown) connected with the upper end of the well point.

As illustrated, the well point comprises, in general, an upper head l, and a lower head or shell 2, these heads being spaced apart axially i30 any desired distance, and having an inner coaxial jetting-and-suction pipe or conduit 3 eX- vtending therebetween and projecting into these respective heads at its opposite ends. A tubular filtering screen, generally designated 4, surrounds I*35 the pipe 3 in radially spaced concentric relation thereto to form an intervening filtrate chamber 5 for receiving the drainage or seepage fluid from the soil after passing through the screen. Rods 6 maintain the filtering screen 4 in radially "40 spaced relation to the pipe 3, and these rodsare arranged in uniformly spaced relation around the pipe 3, and are fixed thereto, as by welding. The rods also serve to reinforce the screen and prevent y -the same from being crushed inwardly, while af- '45 fording unobstucted passages between the rods through which the seepage or drainage fluid may .pass downwardly about the outer surface of the conduit 3. l

Upper head 150 shouldersV 8- and 9 respectively. When the well :55

point has been assembled, the filter screen 4 abuts against the outer shoulder 8 so as to form a smooth joint at this point, whereby the well point may be sunky into the ground and withdrawn without havingv any projections extending from the unit whichfwould tend to resistvthe axial movement of the well point. The upperend of the head I is adapted to be connected with an extension pipe IG, as by a threaded connection II, and the shoulder S forms a seat for the end of this extension), pipe Iii, preventingl the latter from being screwed into the head farther than is necessary. The extension pipe may be of any desired length and is adapted to be connected at itsV upper-end toA a fluid pressure pump or other source of fluid supplyfrom which the jetting vfluid may be conveniently obtained, or it may be connected to a suction #device for with-V drawing the drainage or seepage fluid from the soil through the well point, as will more fully appear hereinafteni f The in'nerfdiameter of the extension/pipe IEI'is` preferably equalto, or slightly greaterthan,the inner diameter of the con- .duit 3 so that a substantially unifo'rrnflow ofthe to `held ther-niin` theiruniformly spaced relation and with their upper ends abuttingfagainst'the lower` face I2' of the depending annular ange I of the upperhead' 'Ig `Thelower portions of the spacingirods '6 Yare,machined down'pas at I3, thereby;affordingrecesses therein, asbest seen in: Figures -2 and 4. A agian-very Shen:` length' .or

pipe, such as designated bythe reference charac-v ter I4,ilits over the assemblyof'rods 6'v and seats :withinth'e recesses i3. ',Q'lfhe depthY ofthe recesses I ASfis preferably equaltothethickness of rods 6, as will be. understood from reference; to Figure .2.,V lhegpipe I 4 yis preferably secured to :the rods 6, Vas by Welding,l and the :lower-end I5 -ofthe pipeI I4, ,terminates on .a leveliwiththe lower Aen'd I6 ofthe. conduit 3, as, doti-1eY lower 4ends ofthe-rods 6.,V In-other Words, the lower end faces of the pipe 4I.4,the spacingrods- 6 and4 thev conduit .3, allplie in 'the same transversethe :pipe 14. f l

` lower shell kThe,loweriheard 2,r according to my improved endface I95-of pipe I 81 provides a shoulder similar, tothe shoulder Brion theuppervheadh gend the lower endi of; the'llter screen 4 abuts, the

upper face I9 ofthepipe I8 and likewise forms a smooth joint at this point.

Secured to the lower end of the shell or pipe I8, as by means of the diametrically extending rivet 20, is a pilot section 2l having teeth or serrations 22 on the lower end thereof. This pilot section facilitates the sinking of the well point in the soil inasmuch as the teeth 22 will break the soil loose below the well point pursuant to a rotary or oscillatory movement of the well pointabout its longitudinal axis. The upper end of the pilot section is reduced in diameter so as to `fit snugly within the lower end of the shell or pipe I8, and thus provides a shoulder 23 adapted to abut against the lower end of the shell or pipe I8, as best seen in Figure 2. The rivet 20 not only serves to'anchor the pilot member to Vthe lowerend of the shell or pipe I8, but also serves to prevent large stones and the like from being drawn or forced up into the interior of the well point.v

lMounted within the shell or pipe i8 so as to be preferably removable, is a frame i24, which is positioned in axially spaced relation to the lower ends of the pipe i4, spacing rods S 'and conduit 3, the frame being secured to the pipe I8, as by means of set screws 24.` For convenience of description, this intermediate space 25 is termed a valve chamber. Thevframe 24 is provided with a bore 26 which is preferably greater than internal diameter of the conduit 3, and the upper face 2'! of the frame constitutes avalve seat for the valve 28, which is disposedin chamber 25. This valve 28 is of ring-like form, and is preferably made of metal or some otherwhard material which is capable of resisting wear during operation thereof,` and the diameter of the opening 29 throughthevalveElis preferably substantially equal to Ithe internal ,diameter of the conduit 3, but less than the internal diameter of the bore 26 in the framev 24. yThus the ring valve 28 overhangs the bore 23, as at 33. During theV jetting operation, the back pressure of the .ietting uid acts` upon the lower face of this overhanging portion 30 of the ring valve 28 and causes the ring valve to be forced upwardly against the seat formed by the lower faces I5, IIand I8 of thev pipe I4, rods 6 and conduit 3. The seating of the' ring valve A2! against its upper seat is represented b'y dotted lines in Figure 2, and when so seated, the ring valve closes lthe lower end of the passages between the spacing rods 5 which normally direct the drainage or `seepage fluid from the filtrate chamber 5 into the valve chamberv 25, from' which this fluid may be withdrawn through the conduit 3` by suction, after the well point'has been stmk to the required depth, Duringthe suction operation, the ring valve 28 will fall of' its own weight, to the .bottom of `the valve chamber 25 and rest upon its seat 21, as represented by full lines in Figure 2. 'I'he primary 'purpose in causing the ring valve 28 to be forced against its upper seat and close the drainage passages is to` prevent the letting fluid from passing into the nitrate chamber and out through the lter screen 4 during the jetting operation. If Ithis outward flow of the jetting fluid through the lter screen were permitted, a considerable portion of the force of the jetting `fluidwould'be lost, whereas by blocking the filtrate chamber against entrance of the `letting fluid during thejetting operation, the fullforce of the jetting fluid is obtained at the lower end of the well vpointwhere it is most desired to erode the soil for the purpose of sinking the Well point.

The frame 24 carries at its lower side a selfclosing check valve 3|, hinged at one side, as at 32, to the lower end of the frameso as to permit the valve 3| to swing open, as to the dotted line position indicated in Figure 2. When closed, the check valve 3| seats against the lower face 33 of the frame 24, and thus closes the otherwise unobstructed axial passage extending from end to end through the well point. A relatively stiii yieldable spring 34 normally holds the check valve 3| closed against its seat 33, and this check valve is preferably made of metal or some other relatively hard material to resist wear which tends to be produced by the repeated impact of the valve against its seat. When the valve 3| is swung to its open position, as shown in dotted lines in Figure 2, the axial passage through the well point is virtually unobstructed from end to end, and the jetting iiuid will follow a straight or axial path through the well point, and hence will reach the lower end of the well point Without any appreciable diminution of its force. This unobstructed straight line or axial passage of the jetting uid thro-ugh the well point is a material improvement over those well points heretofore employed which are so arranged that the jetting iiuid must traverse a tortuous or irregular path in passing therethrough.

The spring 34 is tensioned against the under side of the valve 3| with suiiicient pressure to rmly close the valve against its own weight as soon as the jetting operation ceases, and during the suction operation, the suction will aid materially in rmly holding the valve in its closed position to not only expedite the withdrawal of the drainage or seepage iiuid, but also to prevent the passageof any underlying material into the suction device through the conduit 3. The valve 3| may therefore be said to be self-closing; that is, it will automatically close as soon as the jetting operation ceases. To begin the jetting operation, the pressure of the jetting iiuid on the upper side of the valve 3| automatically causes the valve to swing open and out of the path o-f the jetting fluid, and the Valve will remain open as long as the jetting operation is continued, but automatically closing when the pressure of the jetting uid on the valve is relieved.

Filter screen The lter screen 4 is tubular in form and preferably of special construction so as to obviate the use of external lengthwise reaming bars which have heretofore been employed, and comprises, in general, a laminated foraminous screen preferably composed of three layers, 35, 36 and 3l, superimposed upon each other and Awrapped as a unit about the spacing rods 5, about the reduced end 1 of the upper head and about the upper portion of the short tube or pipe section |4, so as to lie snugly in between the shoulders 8 and I9. The inner screen layer 3'| and the outer screen layer 35 are preferably made continuousv and of comparatively heavy wires interwoven to form a relatively coarse mesh, and of suicient circumferential lengths to extend, in thisinstance, slightly more than two complete .turns around the outer surfaces of the rods 6, so that its ends may overlap, as shown in Figure 3. The other layer 36 is approximately one-half the length of the continuous layers 3l and 35, to wrap around said rods slightly more than a single turn to enable its ends to overlap, and is composed of wiresv of comparatively small gauge interwoven to form a relatively fine mesh. The axial lengths of all the `layers are approximately equal to each other, and equal to the distance between the shoulders 8 and I9, as previously mentioned. The layers may be preassernbled, one upon the other, with their corresponding ends in the same transverse plane, and may then be wrapped iirmly around the outer surfaces of the rods 6 in such manner that the ner mesh layer will be interposed between the inner turn of the coarser mesh layers, as shown particularly -in Figure 3, thus bringing approximately lone-half of the coarser mesh layer in direct contact with the rods, and its remaining half around the outer surface of the iiner mesh layer.

For example, ras shown in Figure 3, one end of the coarse mesh layer 31 is welded or otherwise iirmly secured to the outer surface of one ofthe rods 6, after which, the corresponding end of the iiner mesh layer 35 may be welded or otherwise secured tothe outer surface o-f the coarser layer just beyond the line of securement of the latter layer to the rod, the two layers being then wrapped slightly more than one turn around the outer surfaces of the remaining rods 6. The remaining portion, 35, of the coarser mesh screen is then wrapped another turn around and upon the outer surface of the finer mesh layer 33, and`r slightly beyond the iirst ends of both layers 3l and 35, in overlapping relation, the free end of the layer 35 being welded or otherwise secured to the outer surface of the preceding turn so as to complete the tubular form of the laminated screen.

It will be clear that the coarser mesh layers 35 and 3l cover respectively the outer and inner surfaces of the finer mesh layer 35, toI protect the latter against injury by contact with the rods 6 and with the soil, and at the same time the screens, particularly the finer mesh layer, iilter the seepage'or drainage fluid as it passes from the soil into the well point, tothe exclusion of the solids.

readily during sinking of the well point, as would be the case were this screen directly exposed to the soil, inasmuch as the outer coarser mesh layer displaces the contiguous soil as the well point descends. The rods reinforce and stili'en the lter screen, and prevent the same from being crushed inwardly, thus insuring that the filtrate chamber 5 and the passages leading therefrom will be free to receive the drainage or seepage fluid. The maximum capacity o-f the filtrate chamber under widely varying external or internal radial pressures during the suction-and-jetting operations is therefore maintained.

Operation The Well point is usually placed Vin an upright position with its lower end resting upon the ground at the point where it is toy be sunk, and its upper end is connected to a pressure pump or other source of supply of the jetting iiuid, such as water, which is then caused to pass downwardly into the well point, through the conduit 3 and through the opening 29 in the ring Valve 28, thereby forcing check valve 3| open toallow the iiuid to continue its unobstructed flow through the pilot section 2| to impinge against the underlying soil for erosion purposes. j

The resistance of the soil to the free passage of the fluid through the outlet at the lower end of the well point causes `more or` less of theuuid ,j

Such an arrangement also prevents lthe liner mesh screen from becoming clogged as to become trapped in the lower end below the conduit 3, resulting in an upward deflection of a part of said jetting fluid, with a tendencyto escape through the drainage passages and filtrate chamber 5 and out through thel filterY screefnfd, but this upwardly deflected fluid immediatelyimpinges against the vunder sidevof the overhanging portion of the ringvalve 28 and lifts vthe same into engagement with its upper seat formed by the radially spaced lower'e'nds l5 and I6 ofthe pipe lli and the conduit 3, thus closing off the filtrate chamber and ,drainage passages, and allowing the full force of the jetting fluid to be directed against the underlying soil for displacing the same to cause the'well point to sink therein under its own weight. operation, the sinking'of the well pointmay be aided by a rotary or oscillatory motionof the well point about its vertical axis.

The sinking operation ispreferablycontinued I until the entire length or major portion of the tubular screen 4 is brought below the level of the fluid in the soil to be drained, to allow the drainage of the fluid from the soil through the tubular screen 4 into the filtrate chamber 5. It is to be understood that as long as the jetting operation continues, the valve 3l will be held open by the downward pressure ofthe jetting fluid against the action of' the spring 34,y and that the upward pressure of the vtrapped fluid in the well' point below the ring valve 28 will effectively close the latter against itsA upper Vseat `to prevent the escape of the jetting fluid outwardly. through the screen 4. f

When the well point has been sunk to the required depth, the jetting fluid is shut off, thus permitting the check valve 3| to be closed automatically by its spring 34,'and at the same time, the ring valve 28 will drop by its own weight onto its lower seat 2l,l thus opening communication between the` filtrate chamber 5 and `thevalve chamber 25 to allow the seepage or drainage fluid from the soil to pass through the filter screen YI into the filtrate chamber and thence downwardly 'through the Well point into the suction pump. By

reason of'the fact that the valve 3| remains closed during the suction operation, the entire suction force maybe directed to 'the withdrawal .of the fluid from the soil, leaving'thelower part of the well point below the valve 3l-free from the influencev of the-:suction action. It will be understood that the operations of both valves 28 and' 3| are entirely automatic during the jettingand-suction periods, andthatthe suction action is conned entirely to the withdrawal ofthe seepage or drainageiiuid which enters the filtrate chamber through the filter screen, and the force ofthe letting fluid is confined entirely to the erosion of the soil `below the well point, thus contributing materially to the economic and expeditious sinking of lthe well point into the soil and removal of seepage or drainage fluids therefrom.

In case the area of the soil to be drained is relatively large, a proportionate number of the well points may be similarlyl sunk in or around said area and connected to a common source of supply'for the jettingfluidso that all of them During this jetting may be sunk simultaneously or in quick succession and they may be similarly connected to the same suction device for removing' the seepage or drainage fluid fromthe soil in one operation.

From the foregoing description lof the various elements from which the well point is fabricated, it should be obvious `that theV assembly `is quite simple, and when the parts are completely assembled, the Well point is virtually a rigid integral unit, and isy quite rugged.' Moreover, it willbe noted that the major portion of my new well point is composed of comparatively inexpensive stock materials such as tubing, rods, screen, etc., all of which are readily procurable and comparatively inexpensive. When the various elements are assembled, the Well point unit is of substantially uniform diameter fromend to end, and has no shoulders or projections on the outer surface thereof which offer resistance to the axial movement of the well point into or out of the soil. In other words, the surface of the well point unit is continuous and of substantially uniform smoothness from end, to end.

chamber, a lower head comprising a tubular Shell coaxialwith the inner conduit and into whichthe lower end of" the latter extends, a pipe section having afportion thereof received within the upper end ofv the shell and extending above the upper end of the latter, said shell being secured to the pipe section and said pipe section beingsecured. to the inner conduit in spaced relation to the latter, Athe lower end .of said conduit and the lower end of said pipe `section being disposed in the same transverse plane and constituting an annular valve seat, an inflexible ring valve means withinvv the shell adapted to coact with said seat, and supporting means for said valve means normally supporting said Valve meansin spaced relationto said seat to establish communication between the filtrate chamber and the inner conduit so as to permit withdrawal of the drainage iiuid from the filtrate chamber when suctionl is applied to the conduit, and said valve means being adapted to automatically close against said seat when a jetting fluid is passed through the conduit.

2. A well point having altubular upper head, a tubular filter screen secured at its upper end about said head, a conduit located within and spaced from said filter screen and secured to said head in concentric[relationv thereto, thus providing a drainageA space intermediate the filter screen and conduit, spacing members secured to the conduit about the outer periphery thereof, a pipesection disposed about the lower ends of said spacing members andsecure'd thereto, whereby to provide drainage passages below the drainage `space in' open communication with said drainage space, the upper end of said pipe section projecting withinv the lower end of said filter' screen, the lower end of said pipe. section and the lower end of said conduit terminating in the same transverse plane to providean annular valve seat at the lower end ofthe drainage passages aforesaid, a tubular shell extending about the lower end of said pipe section and secured thereto, a ring valve within said tubular shell adjacent to said seat aforesaid and actuatable by the rearward deflection of a jetting fluid to cause the Valve to, seat against the aforesaid seat and close the drainage passages, means for normally supporting said Valve in spaced relation to said seat, and a normally closed check Valve mounted within the tubular shell and actuatable by said jetting uid to permit discharge of the jetting fluid from the lower end of the shell.

3. A well point comprising tubular axially spaced heads, a conduit extending between said spaced heads and fixed thereto in concentric relation therewith to provide a straight axial fluid passage through the well point from end to end, the lower end of said conduit extending into the upper end of Said lower head in radially spaced relation thereto whereby to form an annular passage therebetween, a tubular filter screen interposed between said heads and surrounding said conduit in radially spaced relation thereto to provide a filtrate chamber therebetween communicating with the annular passage aforementioned, a pipe section surrounding the lower end of said conduit in spaced relation thereto and having its lower portion disposed within the upper end of the lower head, and its upper portion extending within the lower end of said tubular screen, the lower end of said pipe section and the lower end of said conduit terminating in the same transverse plane to provide an annular valve seat, Valve means mounted within the lower head and adapted to coact with said valve seat, said valve means being of ring-like form, and means for normally supporting said valve in spaced relation to said valve seat to establish 40 communication between said filtrate chamber and tion, and said valve means being further adapted to move againstvsaid seat and close the lower end of said annular passage responsive to the passage of a jetting fluid through the well point. 4. A well point comprising an upper tubular head adapted to be interchangeably connected at will with a. source of jetting fluid and with a suction pump, a tubular conduit depending from said head and coaxial therewith, a tubular pipe section surrounding the lower end of the conduit and radially spaced therefrom, a tubular foraminous filter surrounding said conduit and spaced therefrom and coaxial therewith, said lter being secured at its upper end to the upper head, and at its lower end to the upper portion of the pipe sec-tion, a tubular shell having its upper end extending about the lower portion of the pipe section, but terminating at its upper end below the upper end of said pipe section, said shell extending a substantial distance below the conduit and lter, a frame secured within the shell below the lower ends of said conduit and pipe section in axially spaced relation thereto, said frame having an axial bore therethrough, an inelastic ring valve interposed between the frame and the lower ends of the conduit and pipe section and having a portion of the kbody of the ring disposed in overhanging relation to the bore of the frame, the upper side of the frame constituting the lower seat for the ring valve, and the lower ends of the conduit and pipe section together constituting the upper seat, and a selfclosing valve mounted on the frame and normally adapted to 4seat against the lower side thereof toclose the bore through the frame, said ring valve being adapted to automatically seat on its upper seat and said self-closing` valve being adapted to automatically open responsive to the passage of a jetting fluid through the conduit whereby to direct all of the jetting fluid through the shell and outwardly at the lower end thereof.

THOMAS F. MOORE.

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