US 2467826 A
Description (OCR text may contain errors)
April 19, 1949. l. w. HENDERSON ET AL 2,457,826
LIFTING SLIP-JOINT Filed Feb. 5, 1947 INVENTOR.
n BY Patented Apr. 19, 12949 LIFTING SLIP-JOINT Ira W. Henderson, Detroit, Mich., and Hans T. Nilsen, Mathews, Va., assignors to Raymond Concrete Pile Company, New York, N. Y., a corporation of New Jersey Application February 5, 1947, Serial No. I*726,658
(Cl. (il-78) 2 Claims.
An object of this invention is to disclose ways and means for economically sinking into the ground concrete piles of unusual length under unusually diflicult conditions. This invention is an improvement on that disclosed in Upson U. S. Patent No. 1,836,140.
In that patent the shell is made in sections, each larger in diameter than the one below it, and each adapted to surround one of the cylindrical steps of a drive core. Although the patent shows shell sections of diiierent diameters the present invention applies just as well if the sections are of uniform diameters.
To save cost it is desirable to form the shell of as thin material as possible, which means that the shell must be pulled into the ground under tension instead of being pushed or driven down under compression. In order to reduce wear and tear of the soil on the shell sections, a rigid ring of slightly greater diameter than the shell section, is provided to plow a path for each section. Since the shell must have suflicient rigidity to withstand the compression of the surrounding earth after the core is removed and before the concrete is poured, the metal of the shell is preferably corrugated, thereby providing the necessary resistance against crushing.
Shoulders on the drive core are utilized to push down the plow rings and the plow rings serve to pull down the shell sections.
Under certain diicult conditions, such as driving through clay into hardpan, it has been found that some of the bottom shell joints pull apart due to heaving of the ground, allowing water and mud to enter the shell. To overcome that diiculty the present inventors conceived the idea of inserting, at an appropriate point in the shell, a combination lifting slip-joint strong enough, and rigid enough, to hold the shells together and in alignment during shelling-up and other handling operations, but weak enough to slip longitudinally if the upper part of the shell heaves.
There are two plow rings in the joint, each having upwardly and downwardly extending annular fins. The upper n of the inner ring is attached to the bottom of a shell section, and has its lower fin attached to a downwardly extending corrugated Screw collar which is threaded into the upper end of the next lower shell section. The collar has only two or three corrugations, and the gauge of the material is lighter than that of the shell sections.
The upper end of the lower shell section has attached to it the other plow ring. To the upper iin of that ring is attached a plain cylindrical sleeve extending upwardly around the lower end of the shell section above it with packing between the sleeve and the shell. The corrugated screw collar serves to hold the shell together during all handling and shelling-up operations, and then, should the ground heave, this collar slips over the corrugations oi the shell section, and the upper plow ring leaves the lower ring, the lower end of the whole shell being anchored in the hardpan. But no harm is done because the entry of mud and water is prevented by a tubular sleeve and packing. inserted between the sleeve and the shell.
Further and other objects and advantages will be apparent from the specification and claims, and from the accompanying drawings which illustrate what is now considered the preferred embodiment of the invention.
In the drawings:
Fig. 1 shows a driven shell incorporating the invention;
Fig. 2 is an enlarged sectional view showing the invention in detail.
In Fig. 1 the shell has been driven into ground I0. The shell comprises corrugated sections I2, I4, IE, I8 and 2D, each larger in diameter than the one below it. Sections I4 and I6 are joined together by the structure of the invention, which will be described in detail. The other sections are provided at their lower ends with plow rings 22, 24, 26 and 28, each slightly larger in diameter than the shell section to which it is attached. A plate 3U closes the bottom of the shell.
Referring to Fig. 2, 32 is a tubular drive core having a shoulder 34 resting on the upper side of plow ring 36, which has an upper fin 38 attached to the lower end of shell I6, and a lower n 40 to which is attached the top of a short corrugated collar 42 of comparatively light gauge metal, and screwed into the top of shell I4.
Underneath ring 36 is a somewhat similar ring 44 having a downwardly extending iin 46 connected to the top of shell section I4, and an upwardly extending fin 48 attached to the bottom of a tubular sleeve 50 which extends upwardly outside of, and closely adjacent to, the lower end of shell section I6.
The space between -shell I6 and sleeve 50 is calked with packing 52, thus preventing passage of water or mud. Should the joint be subjected to suicient stress to raise ring 36 from ring 44, the corrugations of collar 42 will deform sufciently to slip relatively to shell I4, but no water or mud will enter the shell past sleeve 50.
It is to be understood that the invention is not limited to the specic embodiment herein illustrated and described but may be used in other ways without departure from its spirit as defined by the following claims.
What is claimed is:
l. Means for joining upper and lower adjacent corrugated sections of a shell for a concrete pile, comprising in combination, a plow ring at the bottom of said upper section, a corrugated collar extending downwardly from said ring and screwed into the top of said lower section, a ring at the top of said lower section and in contact with the underside of said first-mentioned ring, and a tubular sleeve extending upwardly from the top of said lower section and surrounding the bottom of said upper section.
2. Means for joining upper and lower adjacent corrugated sections of a shell for a concrete pile, comprising in combination, a plow ring at the bottom of said upper section, a corrugated collar REFERENCES CITED The following references are of record in the le of this patent:
UNITED STATES PATENTS Number Name Date 1,836,140 Upson Dec. l5, 1931