This invention concerns the design of a head that is fitted onto a pile to give vertical and/or angular adjustment.

Piles are used to support wide varieties of structures including domestic property, commercial buildings, industrial buildings, bridges and temporary structures. If the foundation to be supported is cast insitu in concrete, the finished level at the top of the pile and the plumb of the pile is often not critical, as the concrete foundation is cast around the pile. In other applications, such as temporary buildings, piles are often used to support a prefabricated grillage of beams. In these applications it is important that the finished top of all the piles are set to the correct level and plane.

The present invention has been made from a consideration of the foregoing.

According to one aspect of this invention there is provided an adjustable pile head for a pile. The pile head may be angularly adjustable. The pile head may be vertically adjustable. The pile head may be locked in an adjusted position. The invention also provides a pile having a pile shaft and an adjustable pile head according to the preceding aspect of the invention connected to an upper end of the pile shaft.

In at least one embodiment of the invention, the pile head comprises an upper or first member and a lower or second member. Preferably, the members are configured so that the members can move relative to each other to provide angular adjustment of the head of the pile. For example, opposed surfaces of the members may co-operate to provide angular adjustment of the head of the pile.

In at least one embodiment of the invention, the angular adjustment to the head of the pile can be achieved by relative rotation of the upper and lower members. In at least one preferred embodiment of the invention, angular adjustment can be achieved by rotating the upper member, that preferably has an outer part ball shaped surface, inside the lower member, that preferably has an inner part cup shaped surface complementary to the outer surface of the upper member. Preferably, the opposed surfaces of the upper and lower members are part spherical. In this way, the opposed surfaces form a ball or swivel joint and the upper member can be rotated to provide angular adjustment of the pile head in all directions. Preferably, means is provide to lock the members in an angular adjusted position. In this way, the pile head can be fixed in the angular adjusted position. The locking means may fix the angular adjusted position temporarily or permanently.

In at least one embodiment of the invention, the cup and/or ball shaped members define a hollow section within the pile head and the pile head is preferably infilled to give a firm foundation for fixing the supported structure. The infill material can also be used to lock the cup and ball shaped members together in the angular adjusted position and prevent movement of the finished top of the pile. The infill material is preferably flowable to fill the hollow section of the pile head and hardenable in situ. In this way, the pile head forms a solid cap at the top of the pile. The infill material may be grout, concrete, resin, glue or any other suitable filler. The inside of the cup and ball shaped members may be provided with one or more formations such as ribs. Where provided, the ribs may strengthen the co-operating surfaces and/or may assist locking the members relative to each other when the pile head is infilled.

Alternatively or additionally, the cup and ball shaped members may be locked together by any other suitable means such as one or more screws, locking pins or the like. Such means may usefully be employed with infill material to prevent the cup and ball sections moving while the infill material is added and/or before the infill material has hardened. In at least one embodiment of the invention, the pile head is positioned on a pile shaft. Preferably, the lower member of the pile head and the top of the pile shaft are configured for relative movement to provide vertical adjustment of the head of the pile. For example, coupling parts of the lower member and pile shaft may co-operate to provide vertical adjustment of the head of the pile.

In at least one embodiment of the invention, the vertical adjustment to the head of the pile can be achieved by rotating the lower member, that preferably has a screw threaded portion, relative to the upper end of the pile shaft, that preferably has a mating screw threaded portion. The upper end of the shaft may be screw threaded for co-operating with a matching screw thread on the lower member. Alternatively, the upper end of the shaft may be provided with a threaded member for co-operating with a matching screw thread on the lower member. Preferably, means is provided to lock the pile head in a vertical adjusted position. In this way, the pile head can be fixed in the vertical adjusted position. The locking means may fix the vertical adjusted position temporarily or permanently.

In at least one embodiment of the invention, a threaded nut may be provided to lock the lower member relative to the upper end of the pile shaft in the vertical adjusted position. Alternatively or additionally, the lower member may be locked relative to the upper end of the pile shaft by any other suitable means such as the infill material used to lock the upper and lower members of the pile head together.

The upper member may provide the pile head with a flat upper surface. The upper member may be adapted for connection to a structure supported by the pile, for example the upper member may be provided with one or more holes for attaching bolts to fasten the structure to the pile. In at least one embodiment of the invention, the upper member is provided with a top plate that forms the upper surface of the pile head. The top plate can be provided with different designs and/or shapes depending on the proposed use. The top plate may be formed integrally with the upper member or formed separately and attached to the upper member. A range of top plates may be provided for selection and fitment of the required top plate to the upper member for a particular application.

Preferably, the adjustable pile head is constructed from a non corrosive material. One or both members may be made of plastic, optionally reinforced, or fibreglass although other materials such as metal or alloy can be used. One or both members may be made by moulding, casting, machining or other suitable means. The members may be made of the same or different materials and one or both members may be made from a non-corrosive material.

Preferred embodiments of the adjustable pile head of this invention have the advantage of easy adjustment for levelling the finished top of the pile and/or for setting the height of the finished top of the pile, and/or locking in the adjusted position. In this way, a plurality of piles can be installed and the finished tops can be levelled and set to the same height for supporting a foundation such as a pre-fabricated grillage of beams for supporting a structure.

According to another aspect of the invention there is provided method of piling comprising the steps of driving a pile shaft into the ground, providing an adjustable pile head at an upper end of the pile shaft, adjusting the angular position of the pile head for levelling the top of the pile, and infilling a hollow section of the pile head with an infill material that is hardenable to lock the pile head in the adjusted position.

The method may further include the step of adjusting the vertical position of the pile head for setting the height of the pile. The infill material may be flowable to assist infilling prior to hardening. According to another aspect of the invention there is provided an adjustable pile head for a pile, the pile head comprising means for angular adjustment of the pile head.

The means may comprise a swivel coupling. The coupling may be at least partially hollow. The coupling may be locked in the angular adjusted position. For example, the coupling may be infilled with an hardenable filler, for example grout, concrete, resin, glue or the like to lock the coupling in the angular adjusted position. The filler may be flowable prior to hardening. Alternatively or additionally, any other means may be employed to lock the coupling in the angular adjusted position.

The pile head may be adapted for vertical adjustment relative to a pile. The pile head may be coupled to the pile shaft by a threaded coupling that permits vertical adjustment of the pile head relative to the pile shaft.

According to another aspect of the invention there is provided an adjustable pile head for a pile, the pile head comprising means for vertical adjustment of the pile head.

The means may comprise a screw threaded coupling. The coupling may include a screw threaded section for engagement with a mating screw threaded section on the pile. The coupling may be locked in the vertical adjusted position. For example, the coupling may be infilled with an hardenable filler, for example grout, concrete, resin, glue or the like to lock the coupling in the vertical adjusted position. The filler may be flowable prior to hardening. Alternatively or additionally, any other means may be employed to lock the coupling in the vertical adjusted position

The pile head may be adapted for angular adjustment. The pile head may comprise a swivel coupling that permits angular adjustment of the pile head. According to yet another aspect of the present invention there is provided a method of piling comprising the steps of driving a pile shaft into the ground, providing an adjustable pile head at an upper end of the pile shaft, and adjusting the pile head for levelling the top of the pile and/or for setting the height of the top of the pile.

Preferably, the method further includes the step of locking the pile head in the adjusted position. The step of locking the pile head may include infilling a hollow section of the pile head and/or the top of the pile with an infill material. The infill material may harden to form a solid core that locks the pile head in the adjusted position. The infill material may be flowable prior to hardening. The infill material may be selected from the group comprising grout, concrete, resin or glue. Alternatively or additionally, the step of locking the pile head may include the use of mechanical means such as one or more fasteners, for example screws.

According to a still further aspect of the present invention there is provided a method of adjusting the level and/or height of a pile comprising the steps of driving a pile shaft into the ground, providing an adjustable pile head at an upper end of the pile shaft, and adjusting the pile head for levelling the top of the pile and/or for setting the height of the top of the pile.

Preferably, the method further includes the step of locking the pile head in the adjusted position. The step of locking the pile head may include infilling a hollow section of the pile head and/or the top of the pile with an infill material.

The infill material may harden to form a solid core that locks the pile head in the adjusted position. The infill material may be flowable prior to hardening. The infill material may be selected from the group comprising grout, concrete, resin or glue. Alternatively or additionally, the step of locking the pile head may include the use of mechanical means such as one or more fasteners, for example screws

The invention will now be described in more detail by way of example only with reference to the accompanying drawings in which like reference numeral indicate corresponding parts and wherein:

Figure 1 shows a section through an adjustable pile head in accordance with this invention;

Figure 2 shows a section through the pile head of Figure 1 attached to the upper end of a pile shaft and infilled with grout or concrete; and

Figure 3 shows a section through another adjustable pile head in accordance with the present invention.

Figure 1 shows an adjustable pile head in accordance with this invention comprising an upper or first member 1 and a lower or second member 2. The upper member 1 has a part-spherical outer or lower surface Ia that sits in a part- spherical inner or upper surface 2a of the lower member 2. The part-spherical surfaces Ia, 2a co-operate and provide a ball or swivel joint that allows the upper member 1 to be rotated relative to the lower member 2 as indicated by the arrows to give angular adjustment of the upper member 1 for levelling the top of the pile head. In this embodiment, the inside of the pile head has a hollow section defined by the members 1,2. The hollow section may have a shape different to that shown. One or both members 1,2 can be made of, for example plastics, optionally reinforced plastics, although other materials may be used such as glass fibre. Alternatively, one or both members 1,2 can be made of metal or alloy. The members 1,2 can be made by any suitable means, for example moulding, casting, machining. Figure 2 shows the adjustable pile head of Figure 1 set into the upper end of a pile shaft 3. In this embodiment the pile shaft 3 is tubular and the lower member 2 has a spigot 2b that is located in the upper end of the pile shaft 3 to set the height of the top of the pile head. In some embodiments the spigot 2b may have engage a nut (not shown) on the upper end of the pile shaft 3 by means of which the pile head can be adjusted in a vertical direction relative to the upper end of the pile shaft 3 to set the height of the top of the pile head. The upper member 1 can be rotated relative to the lower member 2 to level the top of the pile head as described above with reference to Figure 1.

As shown, having set the height and level of the top of the pile head, the pile is infilled with a suitable infill material 4 such as concrete, grout, resin or glue that hardens in situ to lock the members 1,2 in position and form a solid cap for attaching a support structure (not shown). Alternatively or additionally, the upper member 1 can be locked relative to the lower member 2 in the angularly adjusted position by using screws, locking pins, or another suitable device to secure the members 1,2 together. Where the pile head is infilled, this prevents any relative movement of the members 1,2 when the infill material 4 is added and before it hardens.

Figure 3 shows another pile head in accordance with the invention. This pile head is similar to the pile head of Figures 1 and 2 with the modifications described below and corresponding parts are indicated by the same reference numerals.

In the pile head of Figure 3, upper member 1 and lower member 2 have each been provided with at least one and preferably a plurality of internal ribs 5a and 5b respectively. These ribs 5a, 5b preferably reinforce and strengthen the part-spherical surfaces Ia, 2a of the members 1,2 and may also help to lock the members 1,2 to the infill material 4 where provided to fill the hollow interior of the pile head. The spigot 2b on the lower member 2 is provided with an externally threaded section 6 that is engageable with an internally threaded nut 7 fitted onto the upper end of the pile shaft 3 and allows vertical adjustment of the pile head as indicated by the arrows to set the height of the top of the pile head. A lock nut (not shown) may be provided to secure the pile head in the vertical adjusted position.

The upper member 1 is also fitted with or has an integral top plate 8. The top plate 8 provides the upper surface of the pile head and can be round or rectangular in plan view and can contain connections to suit the supported structure, for example holes to receive fasteners such as bolts (not shown). The top plate 8 may incorporate a bubble level (not shown) to assist levelling the top of the pile while rotating the upper member 1 relative to the lower member 2.

In this embodiment, the ribs 5a extend between the internal surface of the upper member 1 and the top plate 8. The ribs 5b extend between the internal surface of the lower member and an extension of the spigot 2b within the lower member 2. This arrangement strengthens the ribs 5a, 5b to resist relative rotational movement when the interior of the swivel joint formed by the members 1,2 is infilled to lock the members 1,2. Other arrangements of ribs or similar formations to lock the pile head when the members 1,2 are infilled may be employed.

The construction, operation and use of the pile head of Figure 3 will be understood from the description of Figures 1 and 2

As will be appreciated, the invention provides an adjustable pile head that allows the top of a pile to be set to the required height and levelled in a simple manner after the pile has been driven into the ground. In this way, several piles can be installed and set to the same height and level for mounting a structure to be supported by the piles. As a result, installation of the piles is facilitated. In particular, differences in the installed height of individual pile shafts and/or inclination of individual pile shafts from the vertical can be compensated for by the adjustable pile head of the invention.

It will be understood that the invention is not limited to the embodiments above- described which are provided to exemplify the principles or concepts of the invention and that other configurations of pile head may be employed utilising these principles or concepts without departing from the invention.

Other modifications and improvements that can be made will be apparent to those skilled in the art and are deemed within the scope of the invention.