US3422903A

US3422903A - Grouting material circulating valve means in conjunction with earth drilling tubes

Info

Publication number: US3422903A
Application number: US511696A
Authority: US
Inventors: Bengt K B Jansson
Original assignee: Stabilator AB
Current assignee: Stabilator AB
Priority date: 1964-12-22
Filing date: 1965-12-06
Publication date: 1969-01-21
Anticipated expiration: 1986-01-21
Also published as: NO116711B; SE538845C2; FR1473058A; ES320919A1; CH462752A; AT281694B; DE1240012B; FI44566B; GB1125130A

Description

Jan. 21, 1969 B. K. B. JANssoN 3,422,903

GROUTING MATERIAL CIRCU JUNCTION LATING VALVE MEANS IN CON WITH EARTH DRILLING TUBES Filed Dec. 6, 1965 l of 2 Sheet JUNCTION B. K. B. JANSSON Jan. 2l, 1969 GROUTING MATERIAL CIRCULATING VALVE MEANS IN CON WITH EARTH DRILLING TUBES Filed Dec. 6, 1965 Sheet l INVENTOR. E'ezzy /fml z'rgar Jarama/a United States Patent O 3,422,903 GROUTING MATERIAL CIRCULATING VALVE MEANS IN CONJUNCTION WITH EARTH DRILLING TUBES Bengt K. B. Jansson, Skelleftea, Sweden, assignor to Stabilator Aktiebolag, Bromma, Sweden, a Swedish jointstock company Filed Dec. 6, 1965, Ser. No. 511,696 Claims priority, application Sweden, Dec. 22, 1964,

15,509/64 U.S. Cl. 166--224 Int. Cl. E21b 33/138; F16k 21/04 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to devices in conjunction with tubes intended for drilling in earth for performing so-called grouting, the walls of the tube being provided with apertures covered by yielding closure means through which apertures grouting material is to be forced out.

In known grouting methods the drilling operation is performed with a special tube drill of any kind and, after introducing e.g. a so-called sleeve tube into the borehole thus obtained the drill tube is extracted from the borehole. The space between the walls of the lborehole and the sleeve tube is lled with a semi-plastic or hardening mortar, cement or concrete having a low strength.

The known sleeve tubes are provided at uniform intervals with perforations or apertures covered by sleeves which are retained in position by retainers welded to the tube and being e.g. ring formed. When the grouting is performed a so-called double-packer consisting of a perforated tube the two ends of which are provided with bowl-shaped packings of leather or plastic, is introduced into the sleeve tube. The lower end of the perforated tube is closed While the upper end communicates with an injection pump directly or via joint members. Upon pumping the grouting material or mortar through the perforated tube the material flows out through the holes and ills the space between the packings. At increasing pressure the bowl-shaped packings are forced against the inner wall of the sleeve tube and a good seal results. At further increased pressure the sleeves of the sleeve tube expand and burst the surrounding layer of mortar which is forced outwardly into the earth layers. The layer `of mortar prevents the grouting mortar from piercing up to the ground surface along the walls of the sleeve tube or drill tube. When the double-packer is moved to the next hole of the sleeve tube the pump pressure is lowered whereby the sleeve prevents the mortar injected into the earth layers from owing back into the sleeve tube.

`The sleeves of known sleeve tubes consist of rubber sleeves slipped onto the sleeve tube, which sleeves function as so-called valve rubbers.

An important disadvantage of the known sleeve tubes resides in the fact that, owing to the presence of the valve rubbers, the sleeve tube cannot be used simultaneously as a drill tube, for which reason a special drill tube is 3,422,903 Patented Jan. 2l, 1969 required for the drilling operation proper. This is due to the fact that the rubber sleeves with their retainer rings would exhibit a braking and blocking action and' also be wholly destroyed. For natural reasons the sleeves have to be large-sized in dimension or otherwise they woul-d neither be able to bring about the necessary sealing effect nor withstand the mechanical stresses inside the borehole where the rubber sleeves of course will be easily damaged by stones and gravel. The necessity of performing the drilling operation initially with a considerably larger drill tube into which the sleeve tube is then introduced in its final position before extracting the drill tube, is of a great disadvantage.

An object of the present invention is to provide `a device permitting the use `of the sleeve tube itself as a drill tube.

Another object of theinvention is to provide a -device of the character referred to wherein means are provided for covering the apertures in resiliently sealing engagement, said means being comprised of relatively thin resilient iiaps, tongues or the like.

It has been established by experiments that the thin, preferably metallic resilient flaps according to the present invention are entirely superior to the known rubber sleeves. The iiaps according to the present invention are no obstacles in any respects and permit said tube to be used directly as a tube drill. This implies lan important saving of grouting costs.

According to the invention said aps may be attached to the tube on one side of the hole and preferably be bent by prestressing to lie close to the tube in sealing engagement therewith.

The iiaps and/ or parts connected to the flaps are attached to the tube by spot-welding, soldering, cementing or the like.

For each hole of the sleeve tube a -ap is suitably arranged in registration therewith.

The iiaps may be prestressed against the tube to lie closely over the holes of the tube.

Suitable materials to be used for the iiaps according to the present invention are spring steel or another spring material having the corresponding properties.

The present invention will be more penetratingly explained in the following with reference to the appended drawings illustrating an exemplary embodiment of the present invention, wherein:

FIG. 1 is a sectional elevational view of a tube having sleeves of a thin resilient metallic strip material wherein aps are cut out from the strip sleeves;

FIG. 2 is an elevational view of a portion of the tube in FIG. 1;

FIG. 3 is a cross-sectional view along lines III-III in FIG. 2;

FIG. 4 is a longitudinal view of one of the sleeves of the tube in an unfolded state or flattened out from its sleeve form; and

FIG. 5 `is an elevational view of a portion of a tube having flaps separately attached to the tube.

In the drawings 1 indicates the tube, 2 the aps and 3 the apertures in the tube 1 to be covered and sealed.

In FIG. 1 reference number 4 indicates a pump tube adapted to be immersed in the tube 1 and which serves to pump grouting material outwardly through apertures 5 -into the tube 1. 6 indicates one of at least two bowlshaped packings slipped on the tube 4 on both sides of or above and below the series of apertures 5. The flaps 6 assure that grouting material is injected into determinable or optional portions along the tube 1.

According to the principle of the invention the aps 2 comprise a thin, preferably metallic, resilient material. Owing to their thinness of the iaps 2 lie close to the outer surface of tube 1. Thus they will not project materially outwardly from the tube and obstruct the operation of the tube 1 and hence provide the significant advantage that the tube 1 itself may be used as the drill tube of a tube drilling apparatus.

As a matter of fact, the flaps 2 may be of a thickness of one or some tenths of millimeters only. The fiaps suitably have a form adapted to the curvature of the outer surface of the tube.

As will be seen from FIGS. 2 and 4, the flaps 2 may constitute parts of metallic resilient strips 10 provided with slots 7 between which the aps 2 covering the apertures 3 are defined.

In the embodiment illustrated the fiaps 2 extend substantially across the longitudinal direction of the strip 10, i.e. lengthwise the tube 1.

One flap 2 is located in registration with and over each aperture 3 of the tube 1.

The strips 10 may constitute open or broken-through rings lying close to the tube 1. In FIG. 2 one such breakthrough is indicated at 8.

Alternatively, however, the ends of strip 10 may be united by e.g. welding, soldering or the like to form a closed ring.

The strip 10 may be adapted by prestressing to lie resiliently to the tube 1, and the aps 2 may be prestressed in relation to the remaining part of the strip for the purpose of lying irmly over the apertures 3.

In the embodiment illustrated in FIG. 5 individual aps 2 are separately attached to the tube 1, each ap being adapted resiliently to cover its corresponding aperture 3.

In order to attain the desired purpose and effect of the flaps 2 according to the invention, said flaps as well as the strip 10, with great advantage, may consist of spring steel or another spring material having the corresponding properties.

According to the invention the fiaps 2 and/ or the strip may be fixed in their intended correct positions by e.g. spotwelding at suitable locations whereby the material of the aps and strip, respectively, is fixed to the material of the tube 1.

Such iixation by spot-welding involves an extraordinarily great simplification as compared with the previous retainer rings required for the rubber sleeves.

Finally it should be observed that the invention is not to be regarded as being restricted only to the embodiment illustrated and described merely as an example, since various modiiications will occur within imposed limits and, accordingly, it is intended that the drawings be regarded as illustrative and not limiting except as defined in the claims.

Thus it is quite possible to form liaps equivalent to the ilaps 2 by providing in a strip slots of a conguration dissimilar from that of the slots 7 illustrated and described. Accordingly, the slots may present a shape different from the straight form, such as a more or less curved or arcuate form or deviate more or less from the parallelism with the longitudinal direction of the tube 1.

The spot-welding referred to above for the fixation of the strip to the material of the tube 1 may be accomplished for instance at the points 9 in FIG. 2. Reference numeral 9 designates spotwelds which join not only the material of the strip 10 with the material of the tube 1 but join also the two ends of the strip 10. Of course the flaps 2 are not to be spot-welded since they should be able freely to yield resiliently under pressure exerted from within the tube 1.

When special fixation steps are deemed to be necessary, a further possibility to secure the strip material 10 to the tube 1 is to fasten the strip 10 with plastic glue along the surface of the strip.

Of course also other fixation methods known in the art may be used.

What I claim is:

1. Grout circulating valve means for use in deep drilling operations employing a tube having apertures therein opening outwardly through the tube to permit outward delivery of the grout mixture, the apertures being closed by displaceable closing means located on the exterior of the pipe, characterized in that the closing means comprises thin flexible and resilient flaps each of a width and length greater than the diameter of each said aperture and each held in close contact over one said aperture by initial tension, each said ap being fixed against outward exing at one side of the aperture it covers in the direction of the length of the pipe and free to resiliently ex at the opposite side of said aperture in the direction of length of said pipe, and said flaps constitute parts of a resilient strip at least partially surrounding the tube.

2. A valve means according to claim 1, further characterized in that the flaps are metallic and by prestressing are caused to lie close to the tube in resilient sealing engagement therewith.

3. A valve means according to claim 1, further characterized in that the flaps are bonded to the tube as by spot-welding.

4. A valve means according to claim 1, further characterized in that the strip is provided with slots between which the fiaps covering the apertures are delined.

5. A device means according to claim 4, further characterized in that the slots extend substantially across the strip and lengthwise of the tube.

6. A valve means according to claim 4, further characterized in that the strip extends wholly about the tube and in that the ends of the strip are united to form a closed ring.

7. A valve means according to claim 6, further characterized in that the strip is adapted by prestressing to lie resiliently against the tube.

8. A valve means according to claim 4, further characterized in that the flaps are prestressed in relation to the remaining part of the strip.

9. A valve means according to claim 5, further characterized in that the aps and the strip consist of spring steel.

10. A valve means according to claim 1, further characterized in that the strip is fastened to the tube by spotwelding at points between the flaps.

References Cited UNITED STATES PATENTS 1,732,791 l0/l929 Crowell 166-224 X 1,854,518 4/1932 Little 166-224 X 2,071,391 2/1937 Crowell 166-225 X 2,374,169 4/1945 Boynton 166-26 X JAMES A. LEPPINK, Primary Examiner.

U.S. Cl. X.R. l37-512.4