US3345826A

US3345826A - Removable casing construction

Info

Publication number: US3345826A
Application number: US475762A
Authority: US
Inventors: Hignite Walter
Original assignee: WISCONSIN CAISSON Inc
Current assignee: WISCONSIN CAISSON Inc
Priority date: 1965-07-29
Filing date: 1965-07-29
Publication date: 1967-10-10
Anticipated expiration: 1984-10-10

Description

Oct. 10, 1967 w` H|GN|TE 3,345,826

REMOVABLE CASING CONSTRUCTION Filed July 29, 1965 3 Sheets-Sheet l R N k wm s 4 1H w. S R o m L .WA

.M n ww/ Oct. l0, y1967 w. HIGNITE 3,345,826

Filed July 29, 1965 3 Sheets-Sheet 2 REMovABLE cAsING CONSTRUCTION bwa K I l I4', x2] BY WALTER H 6 `ns 7mm .staf/@ Affannevs INVENTOR.

United States Patent O 3,345,826 REMOVABLE CASING CONSTRUCTION Walter Hignite, Milwaukee, Wis., assignor to Wisconsin Caisson, Inc., Milwaukee, Wis., a corporation of Wiscousin Filed July 29, 1965, Ser. No. 475,762 4 Claims. (Cl. 61-53) This invention relates to removable casing construction and has been employed in removable casing used in caisson and cemented piles.

Casing of this nature generally consists of a series of interlocked tubular joints which are driven into the ground following drilling operations and then successively removed as the hole is filled with cement.

Threaded couplings for such casing joints are time consuming for both installation and removal of the casing.

The present invention provides an interlock between the joints of casing that greatly facilitates dropping of the casing in the hole and subsequent removal.

The invention utilizes a bel-l and spigot type of connection between the joints and which is generally constructed by welding a cylindrical ring or skirt of larger diameter to one end of each joint and which is adapted to receive the opposite end of the next joint for a suitable distance.

Interlocking of the joints is accomplished by a bayonet type connection comprising a radial peg secured inwardly of the ring and a generally L-shaped slot in the edge of the spigot member of the next succeeding joint to receive thepeg.l t

All of the L-shaped slots should be orientated in the same direction so that as the casing is lowered into the hole following attachment of eachsuccessive joint the entire assembly may be rotated in a direction that will move each peg in its corresponding slot circumferentially to the dead end of the horizontal portion of the slot where by the joints are interlocked ivertically with one another.

A driver cap is Vprovided for similar interlock in the ring at the upper end of each successive upper joint as the casing is dropped in the hole.

, Generally the driver c ap consists of a dummy cylindrical section with the corresponding interlocking slot and having a central drive portion for receiving the rotary drive member -and for driving downwardly where necessary. y

After such` a casing is installed it is gradually filled with concrete to complete a pile. lFor-this purpose it is desir'l able to remove the casing progressively as the cement be-A comes set yso that the casing is retrieved for repeated use.

Where an Lshaped slot is employed in the cap dif- Patented Oct. 10, 1967 lCe showing a hole partially filled wit-h concrete and with the upper joint of casing being lifted from the string;

FIGURE 2 is a detail section showing the interlocking connection between two joints;

FIGURE 3 is a detail elevation taken on line -3-3 of FIG. 2;

FIGURE 4 is a side elevation of a driver cap partly in section and showing a T-s'lot therein;

l FIGURE 5 is a plan view of the driver cap;

FIGURE 6 is a perspective vievv of the driver cap; and

FIGURE 7 is a detail perspective view showing the clamp for holding the string of casing against loss in the hole while adding or removing a joint at the upper end of the string.

Referring to FIGURE l of the drawing the hole 1 has been drilled in the earth as shown, to a suitable depth and are raised free from the hole at the top.

ticulty arises in removal of the casing during cementing since after lifting the casing to free the upper joints at the top of the hole a reverse turning of the driver cap will not necessarily free the interlock between the upper joint and the nextsucceeding joint so as to permit removal. Instead the cap is often released from the upper joint and the latter remains interlocked to t-he string' of casing.

To overcome this ditlculty the present invention provides a T-slot in the driver cap so that upon reversal in rotation the peg in the slot will move to the opposite dead end and then force the peg at the lower end of the Vupper joint to move into line' with the lvertical portion of t-he L-shaped slot to vertically release the upper joint for lifting by the cap. i

The cap also has one or more vertical openings therei through for the pouring of cement into the string of casing without removing the driver cap for each pouring.

The accompanying drawings illustrate the best mode presently contemplated by the inventor for carrying out the invention.

In the drawings:

FIGURE 1 is a vertical section of a portion of ground 'Each joint 4 in the embodiment illustrated has a skirt 5 welded to its upper end and extending beyond thesame to receive the lower endof the next successive joint.

One or more interlocking pins or pegs'6 extend inwardly from the skirt S and are adapted to be received in corresponding L-shaped slots 7 in the lower end o f the connecting joint when the latter is inserted into the skirt. The horizontal portions 8 of slots 7 extend in thesame circumferential direction from the vertical portions 0f the slots so that when the string of casing is assembled by adding successive joints at the top as the casing is lowered vin the hole, the added joint -is turned or rotated in a direction tocause the pegs 6 to enter the horizontal portions 8 of thev corresponding slots 7. Generally the string will be slowly rotated in the same direction as it drops inthe hole so that the interlock will be maintained at all times. l v

The lower end of the lowermost joint 4 will be provided with a skirt 9 having a cutting edge 10 which is effective to facilitate lowering when the string is thus rotated.

The casing is supported at the top by a clamp 11 which is placed around the upper joint which extends partially in the hole, and engages. the lower edge of the skirt 5 to limit or prevent the downward movement of the string 3 when it is desired to add or to remove a joint at the top. A casing cap 12 is employed to serve as the driving, lifting and lowering connection for the casing; For this purpose cap 12 has' arcylindrical skirt portion 13 simulating the lower end of a joint and having slots 14 'positioned to receive the corresponding pegs 6 on a joint 4 and to enter the skirt 5 carrying the pegs.

The cap 12 has a closure plate 15 with radial strength- 'ening members 16 rigidlyV securing the skirt 13 to a central collar 17 which preferably has a square opening to receive a square drive shaft 18 to drivethe same rotationally. Y

A removable `pin 19 is insertable transversely through the collar 17 and shaft 18 to secure the same together so that vertical movement of shaft 18 will effect corresponding vertical movement of the casing interlocked with the cap 12.

The slots 14 are T-shaped to provide adequate interlock of the cap 12 with the adjacent joint 4 regardless of the direction of rotation of the cap.

Thus, in lowering a string of casing the cap 12 is attached to the upper end of the first joint 4 and lifted by a suitable cable hooked to one of the members 16 which has a hole 20 therein for receiving the cable hook. When the cap 12 and its joint 4 are located over the hole the drive shaft 18 is lowered into collar 17 and pin 19 inserted therethrough. The cable is then unhooked from cap 12 and drive shaft 18 slowly lowers the joint 4 into the hole while turning it in a direction tending to retain the pegs 6 in the horizontal portion 21 of the T-slots 14, until the skirt 5 rests upon clamp 11.

Then the cap 12 is rotated back to register the pegs 6 with the vertical portions of the corresponding T-slots whereupon the cap is lifted off the joint. The cap is then applied to the next successive joint 4 and positioned to drop the same into the upwardly extending skirt 5 of the joint already in the hole. Slow rotation of the second joint in the direction that effects interlock of the lower end thereof will cause the pegs 6 in the first skirt S to enter the L-shaped slots 7 and the portions 8 thereof in the lower end of the second joint. Then the clamp 11 is removed and the string dropped into the hole by lowering cap 12 with shaft 18 while rotating the assembly in a direction maintaining pegs 6 of the iirst joint in the horizontal portions 8 Kof slots 7 in the second joint and pegs 6 of the second joint in the corresponding horizontal portions of slots 14 in cap 12.

Successive joints may be added to the string of casing 3. in the same manner as described for the second joint above.

The hole 1 is generally filled with cement 2 in successive steps wherein a given depth of cement is poured generally corresponding to the length of a joint so that the casing string 3 may be raised one joint at a time and successive pouring operations may await adequate setting of the concrete in the next previous pouring.

By providing one or more openings 22 in the cap plate 15 it is possible to pour a batch of cement into the casing without removing the cap 12. If members 16 are adequately secured to skirt 13 and Collar 17 the plate 15 can be entirely eliminated. However, the plate is useful in generally preventing dropping of foreign items into the casing and hole.

In lifting the casing, when each successive upper joint is fully above ground the clamp 11 is disposed beneath the skirt 5 of the next lower joint to support the string in the hole. Then cap 12 is rotated in a reverse direction by shaft 18 to release the pegs 6 of the skirt 5 that is supported on clamp 11 from the L-shaped slots 7 in the lower end of the upper joint. During this rotation the pegs 6 of the upper joint will move in the horizontal portion of the corresponding T-slots 14 in skirt 13 `of cap 12 to the opposite end of the slot portion so that the cap will remain vertically interlocked with the upper joint.

After release of the interlock between the upper joint and the string, the pin 19 is removed, the shaft 18 is raised froml collar 17 and the cable is secured to the cap and the latter is lifted to carry and remove the upper joint `away `from the string. Then the cap is disconnected from the removed joint and attached to the joint at the top of the string and shaft 18 is secured in collar 17.

The removal of successive joints in this manner continues until the entire string of casing is removed.

If desired the skirt of the driver cap 12 may be reinforced by a ring` 23 welded thereto on the inside of the lower edge and which bridges the slots 14 and prevents deformation of the skirt 12 in use.

The T -slots 14 in cap 12 when employed with L-shaped slots 7 in the joints greatly facilitates lifting and removal of successive casing joints by preferentially maintaining a vertical interlock between the cap and the upper joint while rotating the same in a reverse direction for disconnecting the upper joint from the casing string.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. The combination in a string of casing of a plurality of casing joints each having a skirt at its upper end receiving the lower end of the adjacent joint, a bayonet connection between adjacent joints comprising at least one inwardly extending peg in the skirt and an inverted L-shaped slot in the end of the adjacent joint and receiving the corresponding peg, the horizontal portions of all of said inverted L-shaped slots extending in the same circumferential direction from the vertical portions thereof, and a driver cap for manipulating the string of casing and for successively adding joints thereto and removing joints therefrom, said driver cap having a skirt simulating the lower end of a joint and adapted to enter the skirt on the upper end of any joint and to removably interlock therewith both rotationally and vertically, said cap skirt having a T-shaped slot therein for receiving each corresponding peg in said joint skirt to maintain the vertical interlock therewith for either direction of rotation of the driver cap.

2. The construction of claim 1 in which said driver Cap has one or more openings therethrough for the pouring of concrete into said casing string without removal of the cap therefrom.

3. The construction of claim 1 in which said driverv cap has a reinforcing ring welded inside the lower edge of the skirt thereof.

4. The combination in a vertical string of casing of a plurality of casing joints having loose bell and spigot interconnections therefor, the adjacent joints being rotationally and vertically interlocked by a peg extending radially from the upper end of `one member of the interconnection and disposed in an inverted L-shaped slot in the lower end edge of the cooperating member of the interconnection, the horizontal portions of said slots extending in the circumferential direction of rotation of the casing whereby the pegs are normally retained seated in said horizontal portions and retain the joints against vertical separation, and a driver cap for manipulating the string of casing and for successively adding joints thereto and removing joints therefrom, said driver cap simulating the lower end of a joint and adapted to interconnect with the upper end of any joint, said cap having a T- shaped slot in the lower edge thereof for receiving each corresponding peg of the upper end of a casing joint to maintain the vertical interlock therewith for either direction of rotation of the driver cap.

References Cited UNITED STATES PATENTS 2,693,343 ll/l954- Darin et al. 175--321 FOREIGN PATENTS 30,324 10/1959 Finland. 162,023 1/ 1958 Sweden.

DAVID J. WILLIAMOWSKY, Primary Examiner. JACOB SHAPIRO, Examiner.

Claims

1. THE COMBINATION IN A STRING OF CASING OF A PLURALITY OF CASING JOINTS EACH HAVING A SKIRT AT ITS UPPER END RECEIVING THE LOWER END OF THE ADJACENT JOINT, A BAYONET CONNECTION BETWEEN ADJACENT JOINTS COMPRISING AT LEAST ONE INWARDLY EXTENDING PEG IN THE SKIRT AN AND INVERTED L-SHAPED SLOT IN THE END OF THE ADJACENT JOINT AND RECEIVING THE CORRESPONDING PEG, THE HORIZONTAL PORTIONS OF ALL OF SAID INVERTED L-SHAPED SLOTS EXTENDING IN THE SAME CIRCUMFERENTIAL DIRECTION FROM THE VERTICAL PORTION THEREOF, AND DRIVER CAP FOR MANIPULATING THE STRING OF CASING AND FOR SUCCESSIVELY ADDING JOINTS THERETO AND REMOVING JOINTS THEREFROM, SAID DRIVER CAP HAVING A SKIRT SIMULATING THE LOWER END OF A JOINT AND ADAPTED TO ENTER THE SKIRT ON THE UPPER END OF ANY JOINT AND TO REMOVABLY INTERLOCK THEREWITH BOTH ROTATIONALLY AND VERTICALLY, SAID CAP SKIRT HAVING A T-SHAPED SLOT THEREIN FOR RECEIVING EACH