US 3625012 A
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Description (OCR text may contain errors)
Dec. 7, 1971 s. THORBURN SELF-LOCKING PILE JOINT 2 Sheets-Sheet 1 Filed Ndv. 19, 1969 i v... 01 u .0 b A. v ma I l I. o a n 4 In ver llor SAMUEL fimmumv Attorneys Dec, 7, 1971 s. THORBURN 3,625,012
I SELF -LOCKING PILE JOINT Filed Nov. 19, 1969 2 Sheets-Sheet 2 I nventor 6Z4 MUEL 7 /025 ue/v Attorney! United States Patent 3,625,012 SELF-LOCKING PILE JOINT Samuel Thorburn, Glasgow, Scotland, assignor to Logistics Limited, Great Britain Filed Nov. 19, 1969, Ser. No. 878,056 Claims priority, application England, Feb. 4, 1969, 6,059/ 69; May 22, 1969, 26,064/ 69 Int. Cl. E02b /30; E04b 1/48 US. Cl. 61-56 12 Claims ABSTRACT OF THE DISCLOSURE Two piles are joined together by interfitting means in their opposed ends. One pile has a tube embedded therein, the tube having one, open, end flush with the end face of the pile and its other end being flared and closed. The other pile has a rod whose end is cut projecting from it. The rod is laced in the tube and as the pile is driven the cut end is forced by a wedge into the flare of the tube, thus locking the piles together.
This invention relates to a self-locking joint in piles.
The length of a single pile is limited by the need to transport it, raise it into position for driving, and so on. There is thus a need for a means of joining piles together to allow piling to a depth greater than the length of a single pile.
An object of the present invention is to provide an improved pile joint.
The present invention is a self-locking pile joint including first and second piles having cooperating end faces, a rod having one end embedded in the pile and a second, sa'w-cut end projecting from the end face of the first pile, a tube communicating at one end with said end face of the second pile, embedded in the second pile and being at its other end flared and closed, and a wedge member for engagement with the saw-cut end of the rod and with the closed end of the tube, the rod and tube interfitting and the wedge member splitting the saw-cut end of the rod to secure and wedge together the two piles.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in 'which:
FIG. 1 is a sectional elevation of a pile joint according to the present invention;
FIG. 2 is a sectional elevation of a. second embodiment before the joint is made;
FIG. 3 is a view similar to FIG. 2 but showing the finished joint; and
FIG. 4 is a section on A-A of FIG. 2.
Referring now to FIG. 1, two precast concrete piles 10, 11 prestressed by wires 22 are located end-to-end, a thin layer of jointing material 12 being inserted between cooperating end faces a, 11a. The jointing material is, of course, capable of withstanding the stresses of pile driving and serves to absorb irregularities in the end faces 10a, 11a. A bituminous-impregnated asbestos material may be used.
One pile, in this embodiment the upper pile 10, has one end of a rod 13 cast into it, abutting a metal plate also cast into the pile. The other end of the rod 13 projects from the pile 10, and this end has a single diametrical saw-cut through it. The plate 15 assists in bonding the rod 13 into the pile 10.
The other pile 11 has a metal tube 14 embedded in it, one end of the tube being flush with the end face 11a of the pile 11. The other end of the tube 14 is flared and closed by a closure 16 and the closure 16 supports an upstanding wedge member 17 which is, in this embodiment, the same length as the flare of the tube 14. The rod 13 and tube 14 interfit.
The embodiment shown in FIGS. 2 to 4 is similar to that of FIG. '1, and similar parts are denoted by like reference numerals. In this embodiment, however, the rod 13 is modified in that two, mutually perpendicular saw cuts 18, 19' through it, each saw-cut terminating in one of two mutually perpendicular holes 20, 21 drilled through the rod 13, the holes 20, 21 being normal to the longitudinal axis of the rod 13. The holes 20, 21 reduce the possibility of the saw-cuts 18, 1-9 elongating under piling pressure since the stress concentration at their internal ends is reduced by providing a smooth-curved surface. In this embodiment, the wedge member 17 is of circular cross-section.
In use, the lower pile 11 is driven to a suitable depth. The other pile 10 is then positioned with the rod 13 projecting into the tube 14 and is driven in the normal way, this action forcing the saw-cut or cuts over the wedge member 17 to lock the piles together. The wedge 17 may either be previously fixed to the closure 16 or may be inserted in the cut or cuts before the pile 10 is driven.
Various modifications may be made to the embodiments described above.
The rod and tube are preferably circular in crosssection, but other shapes may be used. The rod may also be replaced by an elongated hollow member, and the work rod is used herein and in the claims as including such a member.
The metal plate 15 may be dispensed 'with, in which case bonding between the rod and the pile may be assisted by indenting the surface of the rod which is enclosed by the pile, or by suitably increasing the enclosed length of the rod.
Although one rod-and-tube combination is used in the embodiments described, it will be apparent that a number of such combinations may cooperate to join a pair of piles.
Tlhe rod, tube and plate may suitably be of mild stee The application of the present invention is not limited to concrete piles, but applies equally to piles of, for example, timber and steel.
1. A composite pile comprising first and second constituent piles each made of reinforced concrete and arranged end-to-end, opposed end faces on said constituent piles, and a rigid and tension-resistant joint connecting said constituent piles and maintaining said end faces in abutting relationship; said joint comprising a metal spigot extending axially of and anchored within said first constituent pile and projecting outwardly from said end face of the latter, means in the second constituent pile defining a socket extending internally and axially thereof and terminating at its outer end at said end face of the second constituent pile, and said means defining also a base closing the socket at its free end and forming laterally splayable locking sections; and a wedge member abutting said base of the socket, wedgingly engaging between said looking sections, and laterally splaying the latter into locking engagement with the means defining the socket.
2. A pile as claimed in claim 1, wherein said cavitydefining means is a tube embedded in said second pile and having a closure for supporting said wedge member at the end of the tube remote from the end face of said second pile.
3. A pile as claimed in claim 2, wherein the end of the tube for supporting the wedge member is outwardly flared so as to enlarge the cavity only in the vicinity of the wedge member.
4. A pile as claimed in claim 1, wherein said cavity defining means is a tube embedded in said second pile and is outwardly flared so as to enlarge the cavity only in the vicinity of the wedge member.
5. A pile as claimed in claim 1 in which the spigot anchored in said first pile abuts a metal plate embedded in said first pile.
6. A pile as claimed in claim 1, including first and second mutually perpendicular diametrically-disposed slots in said spigot, said Wedge member being circular in cross section.
7. A pile as claimed in claim 6, wherein the bottom of each slot has a smooth-curved surface to relieve stress concentration.
8. A pile as claimed in claim 1, including a jointing material inserted between the end faces of the two piles.
9. A pile as claimed in claim 8, in which the jointing material is of a bituminous-impregnated asbestos material.
10. A pile as claimed in claim 1, in which the spigot is of circular cross section.
11. A method of forming a jointed composite reinforced concrete pile comprising casting a first constituent reinforced concrete pile with an end abutment face and with an axial socket closed at its inner end and terminating at its outer end at said end abutment face; casting a second constituent reinforced concrete pile with an end abutment face and anchoring one end of a cold-deformable metal rod in said second constituent pile with its other end projecting axially outwardly from said abutment face forming a spigot, forming an axial slot in the end of said spigot, inserting said spigot into said socket until said end faces of the constituent piles are in abutment and laterally splaying the slotted end of said spigot by wedging until said end grippingly abuts the Wall of the socket.
12. The method according to claim 11, including the step of inserting adhesive between the end faces of the constituent piles prior to their being brought into abutment.
References Cited UNITED STATES PATENTS 736,891 8/1903 Stempel 61-54 1,340,397 5/1920 Nagel 6156 2,065,507 12/1936 Alexander 6156 3,438,659 4/1969 Waldron 287127 R FOREIGN PATENTS 747,969 1933 France 287124 436,041 1935 Great Britain 287-124 13,232 1924 Netherlands 6153 JACOB SHAPIRO, Primary Examiner US. Cl. X.R. 287124, 127