NZ242474A - Tapered sleeve joining member for pre-cast elongate concrete members - Google Patents

Description

?4?«- T I i NEW ZEALAND > v \\ iV t 13 OCT J9°3 n PATENTS ACT 1953 \\ ' COMPLETE SPECIFICATION r | \! ^7 / AFTER PROVISIONAL NO: 242474 DATED: 23 JULY 1992 IMPROVEMENTS IN AND RELATING TO CONNECTING SYSTEMS WE, FIRTH STRESSCRETE LIMITED (in Voluntary Liquidation), of 102 Lunn Avenue, Mt Wellington, Auckland, New Zealand, a New Zealand company, hereby declare'the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - 2 - p 4 The present invention relates to improvements in and relating to connecting systems and in particular but not exclusively to a method and apparatus for interconnecting elongate members such as concrete piles.

Pre-cast concrete piles are used to support buildings, bridges, road formations and other types of civil engineering structures. The piles can be of any cross-sectional shape but are most commonly square, rectangular, octagonal, hexagonal or circular.

For ease of manufacture, transport, handling and driving into the ground, piles are typically cast in short lengths. Then, as each pile is driven into the ground, a subsequent pile is required to be joined on to the preceding pile and the driving continues until the required depth has been reached.

To the present time various methods have been proposed for joining piles together in such situations but none of these previous methods has provided an efficient, effective and low cost method of doing so.

It is thus an object of the present invention to provide?a method and/or apparatus for the efficient, effective and relatively low cost joining of elongate 24247 4 members together which in one embodiment may be suitable for joining pre-cast concrete pile sections together.

Further objects of the present invention will become apparent from the following description.

According to one aspect of the present invention there is thus provided a method of joining elongate members together, said method comprising the providing of one or more holes in at least one end of the respective elongate members, each of said holes being of a size commensurate with the compressed diameter of a split-tube joining means, said method further comprising inserting respective ends of said split tube joining means into respective holes in said elongate members whereby the expansion of said split-tube joining means within the respective holes will provide a friction grip therein to hold said elongate members together.

According to a further aspect of the present invention there is provided a joining means for joining elongate members, said joining means comprising an elongate hollow member having a longitudinal split therein extending between its respective ends, the material of said hollow member expanding the hollow I I member following its compression, said hollow member cPi \uj\ being able to be compressed for insertion into '.2 I c3 \ Ui \ respective holes provided in the ends of elongate lui 1 , \%\ » '• c£ \ members to be joined but by subsequent expansion of said iti-' ifvj\ \ \ hollow member within said holes after insertion 24 247 4 therein provides a frictional grip with respect to the elongate members so as to hold said elongate members together and wherein the ends of said hollow member are tapered.

According to a further aspect of the present invention there is provided a plurality of elongate members joined together by the method and/or jointing means defined in the paragraphs immediately above.

Further aspects of this invention which should be considered in all its novel aspects, will become apparent from the following description given by way of example of possible embodiments thereof and in which reference is made to the accompanying drawings wherein: Figure 1: Shows a pair of concrete piles joined together and according to one possible embodiment of the invention; Figure 2; Shows a view along arrows A-A of figure 1; Figure 3: Shows very diagrammatically a side perspective view of a split-tube joining means according to one embodiment of the invention.

Referring to the accompanying drawings, in one possible embodiment of the invention, a pair of concrete N.Z. PATFNT OFFiCE - 6 DEC 1996 RLCSYkQ 24 2 4 piles 1 and 2 are shown joined together by an elongate split-tube joining means referenced generally by reference 4.

The respective ends of the piles 1 and 2, are shown provided with a taper 10 and are also shown provided with one or more holes 3, substantially parallel to the longitudinal axis of the respective pile 1,2. The number of the holes 3 which are required in the end of each pile 1,2 will be determined by the tension capacity required in the resultant joint to resist driving stresses and other applied blows and by the length and diameter of the split tube 4.

The diameter of these holes 3 will be closely controlled so as to give a friction grip on a split-tube joining member 4 after it is driven into the hole and allowed to expand. The diameter will therefore be commensurate with the compressed diameter of the split-tube joining member 4.

In the particular embodiment shown in the drawings, .four holes 3 are shown provided in the end of each pile 1,2 but any number could be provided. It is envisaged that the holes 3 could be formed during the moulding process or alternatively for example could be subsequently drilled. The technique used will generally be dependant on the nature of the material of the members 1,2, to be joined and while in the embodiment 24 2 4 described this may suitably be concrete, in other embodiments the members 1,2 could be of plastics, wood, metal or any other required material.

In the case of concrete piles the lower pile 2 will be driven into the ground and a split-tube connector 4 will then have one of its ends 6 driven into the respective hole 3. Typically this will be by a tapered female driver tool used on a jack hammer. One of the split-tube members 4 will be inserted into each of the holes 3 provided in the lower pile member 2.

In the embodiment shown the upper surface of the lower pile 2 is shown provided with a layer of a cushioning material 7 through which the upper ends 6 of the split-tube members 4 will project. Also in the embodiment shown, each of the members 4 is shown provided with a ring 9, suitably a metal ring, which is shown about a medial position and controlling the maximum expansion of the ends 6 after insertion into the respective holes 3 and in this embodiment the rings 9 are shown embedded in the cushioning material 7. .1 <, Once the split-tube members 4 have been inserted into the' respective holes 3 in the bottom pile 2 the upper pile 1 will now be driven down until its bottom end 10 contacts the cushioning material 9. Driving will then continue and the process repeated with further # 24 2 4 piles (not shown) being joined on until the entire pile assembly has reached the required depth in the ground.

It will be appreciated that after being driven into the holes 3 the expansion of the ends 6 of the member 4, controlled if appropriate by respective rings 9 about the central portion of the members 4, will provide a frictional grip between the member 4 and the pile material about the hole 3.

In figure 3 a split-tube joining member 4 is illustrated very diagrammatically and shown provided with respective tapered ends 8 to facilitate insertion into the holes 3 and with an elongate slot 5 extending the length of the member 4 allowing the compression of the tube ends 6 and their subsequent expansion to frictionally grip within the holes 3, the extent of the expansion being controllable by a ring 9 as shown in figure 3, if required.

The elongate split-tube members 4 may suitably be of a metal or metal alloy so as to provide the required tension capacity. It has been found in experimentation that expansion of the member 4 after insertion into the holes 3 %ill provide a frictional grip between the member 4 and the material about the hole 3 along the entire length of the hole .""""in a structural joint, such as in the connection of piles, the joint provided by the 242 members 4 can become stronger over time as the member 4 will be able to accommodate movement between the pile members. This contrasts with what would happen with other jointing members such as bolts which would tend to loosen as the members joined by the bolt moved.

Thus, by this invention there is provided a jointing method and/or jointing apparatus which enables a speedy and efficient jointing of members to be achieved.

Where in the foregoing description reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims. ,£v 2 4 2 4 7 4

Claims (2)

WHAT WE CLAIM IS:

1. A method of joining elongate members together, said method comprising the providing of one or more holes in at least one end of the respective elongate members, each of said holes being of a size commensurate with the compressed diameter of a split-tube joining means, said method further comprising inserting respective ends of said split tube joining means into respective holes in said elongate members whereby the expansion of said split-tube joining means within the respective holes will provide a friction grip therein to hold said elongate members together.

2. A joining means for joining elongate members, said joining means comprising an elongate hollow member having a longitudinal split therein extending between its respective ends, the material of said hollow member expanding the hollow member following its compression, said hollow member being able to be compressed for insertion into respective holes provided in the ends of elongate members to be joined whereby subsequent expansion of said hollow member within said holes after insertion therein provides a frictional grip with respect to the elongate members so as to hold said elongate members together and wherein the ends of said hollow member are tapered. H.7.. PATFN7 OFFICE -6 DEC 1996 H.:Ct!v'£0 - 10 - A method as claimed in Claim 1 wherein said elongate members are concrete piles and said method comprises the placement of cushioning means between adjacent elongate members with said split-tube joining means extending through said cushioning means. A method as claimed in Claim 1 or Claim 3 wherein a ring is provided about said split-tube joining means to control the expansion thereof. A method as claimed in Claim 3 or Claim 4 when dependant on Claim 3 wherein said joining means is positioned within one of said holes in a first pile and a second pile is then driven down until its bottom end contacts said cushioning material and wherein said driving will continue and the process repeated with further piles until an entire pile assembly has reached the required depth in the ground. A method as claimed in any one of Claims 1, 3, 4 and 5 wherein the ends of said split-tube joining means are tapered to facilitate insertion into the h<51es of respective elongate members. A method of joining elongate members together substantially as herein described with reference to the accompanying drawings. 7 A 11 9 . 10. 11. 12 . A pile assembly formed by the method of any one of Claims 1 and 3 to 7. A joining means as claimed in Claim 2 including a ring provided about said elongate hollow member to control the expansion thereof. A joining means as claimed in either of Claims 2 and 9 wherein said elongate hollow member is of metal with its ends adapted to be contactable and driven by a driver tool for insertion of the elongate hollow member into a concrete pile. A joining means substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings. A concrete pile assembly utilising the joining means of any one of Claims 2 and 9 to 11. g/specs/682315COM IES LIMITED N.7.. iVTr ■ —- r.'C -6 DEC 1996 V L.xJ