BACKGROUND
Technical Field
The present invention relates generally to driving foundation piles into the ground and more particularly relates to a system for installing hollow foundation piles using a pile having one or more pairs of drive slots.
Description of Related Art
The traditional method for driving a hollow foundation pile in the ground uses a pile having two pairs of axially spaced drive pin holes for attachment of a drive head, in hard soils, the drive head can be attached to the pile with two pins, otherwise one drive pin is usually sufficient. When the pile has been driven the pin or pins are removed and the drive head detached. While effective, it is time consuming and cumbersome to attach and remove the pile from the drive head and limits the depth to which the pile can be driven into the ground since the drive pins must at some point be removed.
There is therefore a need for a pile installation system that facilitates attachment and detachment of the pile from the drive head and allows the pile to be driven to a desired depth without concern for removing drive or attachment pins from the pile.
SUMMARY OF THE INVENTION
A pile installation system according to the invention includes a pile having one or more pairs of cooperating drive bar slots opening upwardly on the top end of the pile and one or more pairs of attachment pin holes axially spaced below the lower ends of the pile drive bar slots. A drive head includes a drive collar having a hollow interior, a lid covering the top of the drive collar, and one or more drive bars affixed to the underside of the lid. The pile is engaged with the drive head by inserting the pile in the drive collar, rotating the pile until the drive bar slots radially align with the drive bars, and further inserting the pile in the drive collar until the drive bars engage the drive bar slots and the top of the pile abuts the lid. The pile may further be attached to the drive head by inserting an attachment pin in cooperating attachment pin holes in the drive collar and pile.
A second embodiment of a pile installation system includes a pile having a tubular body, a pair of drive pin slots and a pair of attachment pin holes axially spaced below the drive pin slots on opposite sides of the top end of the pile. A drive head includes a drive shaft and a circular flange extending radially from the drive shaft. The drive shaft includes a pair of drive pin holes and a pair of attachment pin holes axially spaced below the drive pin holes. The pile is attached to the drive head by preinstalling a drive pin in the drive pin holes in the drive shaft, inserting the drive shaft into the pile, aligning the drive pin with the drive pin slots in the pile and fully inserting the drive shaft in the pile until the drive pin engages the lower ends of the drive pin slots. An attachment pin may then be inserted into cooperating attachment pin holes in the pile the cooperate with the attachment pin holes in the drive shaft to secure the pile to the drive head.
In both embodiments, once the pile is attached to the drive mechanism, the pile can be picked up and positioned where desired for driving into the ground.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are upper right and upper left perspective views, respectively, of a foundation pile having two pairs of drive pin slots according to the invention.
FIG. 2A is an exploded upper perspective view of a drive head and a pile installation tool according to the invention.
FIG. 2B is an upper perspective view of the drive head and pile installation tool shown in FIG. 2A in an assembled configuration.
FIG. 3A is a exploded upper perspective view of a foundation pile and a drive head connected to a pile installation tool according to the invention.
FIG. 3B is an upper perspective view of the foundation pile and a drive head connected to a pile installation tool shown in FIG. 3A in an assembled configuration.
FIG. 4A is an elevational view of the drive head shown in FIGS. 2A-3B.
FIG. 4B is a bottom plan view of the drive head shown in FIG. 4A taken along lines 4B-4B.
FIG. 4C is a sectional view of the drive head shown in FIG. 4A taken along lines 4C-4C.
FIG. 5 is an upper perspective view of an attachment pin used to connect the drive head to the foundation pile.
FIG. 6 is a lower perspective view of the drive head shown in FIGS. 4A and 4B with a cut away to show the interior of the drive head.
FIGS. 7A and 7B are right and left upper perspective view of a second embodiment of a pile according to the invention.
FIGS. 8A and 8B are exploded and assembled lower perspective views thereof.
FIG. 9 are plans view of drive and attachment pins thereof.
FIGS. 10A-10C are lower perspective views of a drive head being attached to a pile according to the second embodiment.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
A foundation pile installation system according to the invention comprises a pile 10, seen in FIGS. 1A and 1B, and a drive head 12 and a pile installation tool 20, seen in FIGS. 2A and 2B. The pile 10 is a hollow pile, generally having a helical flange 14, the pile being of the type that is installed in the ground using rotation and downward pressure (known in the field as “crowd”). Whereas a prior art pile has two pairs of pin receiving holes at the top end of the pile for receiving pins with which to attach a pile installation tool to the pile, a pile as seen in FIGS. 1A and 1B according to the invention, has two pairs of drive bar slots 16 on opposite sides of the pile and a single pair of pile attachment pin holes 18 as seen below the drive bar slots. In the illustrated embodiment, two pairs of drive bar slots 16 are disposed at 90° angles around the top of the pile. In another embodiment, only one pair or more than two drive bar slots are provided.
As seen in FIGS. 2A and 2B, the drive head 12 is configured for attachment to a pile installation tool 20 and includes a drive head cap 21, a lid 22 and a drive collar 24 descending from the lid. The drive head cap 21 includes drive cap attachment holes 25 for receiving a drive head attachment pin 33 and the drive collar 24 has drive collar attachment pin holes 26 for receiving a pile attachment pin 34 (discussed below).
With reference now to FIGS. 3A-3B and 4A-4C, the hollow interior of the drive collar 24 is sized to receive a pile 10 and includes a pair of drive bars 30 arranged in a cross key configuration (see FIGS. 4B and 6). The drive bars 30 are directly secured to the underside of lid 22 and are sized to be closely received in drive bar slots 16 in the top of the pile 10. While the illustrated embodiment shows a pair of drive bars, in another embodiment one or more than two drive bars may be provided.
As seen in FIGS. 3A and 3B the drive head 12 is attached to the pile 10 by lowering the drive collar 24 over the top of the pile 10, twisting the pile until the drive bar slots 16 are radially aligned with the drive bars 30, then further lowering the drive collar 24 over the pile 10 until the drive bars 30 are receiving in the drive bar slots 16. It will generally be necessary to pick up the pile to move it to where it will be installed in the ground, so a pile attachment pin 34 can be installed in the pile attachment pin holes 18 in the pile 10 and in the cooperating drive collar attachment pin holes 26 in the drive collar 12 to secure the pile to the drive collar to allow the pile to be picked up by the pile installation tool 20 and moved to its installation location. Once the pile is established in the ground, the pile attachment pin 34 can be removed. Downward pressure by the pile installation tool and drive head on the pile will maintain the drive bars 30 in engagement with the drive bar slots 16 on the top of the pile. Once the pile has been driven to a desired depth, the drive collar 24 can be removed without the necessity of removing any attachment pins.
In another embodiment of the invention shown in FIGS. 7A-10C the pile 110 includes a pair of upwardly opening drive bar slots 116 disposed on opposite sides of the top end of the pile as best seen in FIGS. 7A-7B. The illustrated embodiment shows one pair of drive bar slots 116, but other embodiments may include two or more pairs of drive bar slots 116. Attachment pin holes 118 are axially spaced below the lower ends 119 of the drive pin slots 116 and radially aligned with the drive pin slots 116. A helical flight 114 is provided towards the lower end of the pile.
In FIGS. 8A-8B it is seen that a drive head 112 is attached by inserting a drive head attachment pin 133 into drive cap attachment holes 125 provided in a drive head cap 121 into a driving rig 120. The drive head 112 includes a circular flange 122 that extends radially from the drive shaft 124. Drive bar holes 126 and attachment pin holes 128 are provided in the drive shaft 124 to receive drive bar 130 and attachment pin 134, respectively, shown in FIG. 9.
With reference now to FIGS. 10A and 10B, it is seen that the drive head 112 is attached to the pile 110 by preinstalling a drive bar 130 in the drive bar holes 126 in the drive shaft 124 and then inserting the drive shaft 124 into the hollow interior of the pile 110 as shown. In the illustrated embodiment, each drive bar slot 116 has tapered edges 132 to guide the drive bar 30 into the slot 16 as the drive head 12 is inserted into the pile. When the drive head 112 is fully inserted into the pile 110, the drive bar 130 orients the pile 110 so that the attachment pin holes 128 of the drive shaft 124 align with the attachment pin holes 118 of the pile 110, whereupon an attachment pin 134 can, if needed, be inserted mutually through the attachment pin holes 118 of the pile 110 and the attachment pin holes 128 of the drive shaft 124 to secure the drive shaft 124 to the pile 110. The pile can then be positioned where desired and driven into the soil. When the pile 110 has been driven down to a level where the attachment pin 134 is just above the ground, the attachment pin 134 can be removed and the pile 110 driven further into the ground, using only the drive bar 130, to a desired depth. Finally, when the pile has been driven to its specified depth, the drive shaft 124 can easily be separated from the pile by lifting it up. The drive slots 116 allow the pile to be driven to its specified depth even though the drive pin 130 may be below ground level.
As seen in FIGS. 8A-8B and 10A-10C, dual fins 138 descend from the lid 122 of the drive head 112 which excavates a trench in the ground around the top of the pile 110 as it nears depth. The trench allows use of the drive pin slot 116 as an inspection port, provides a reference point to install a concrete vibrator in the pile to ensure proper concrete consolidation, and allows air to escape while the concrete is being vibrated.
One advantage of the second embodiment of the invention is that the drive pin slots 116 in the pile 110 make securing the drive shaft 124 to and disengaging the drive shaft from the pile is facilitated by the ability to slide the drive pin 130, preinstalled in the drive shaft 124, in and out of the drive slots 116.
There have thus been described and illustrated certain embodiments of a foundation pile installation system according to the invention. Although the present invention has been described and illustrated in detail, it should be clearly understood that the disclosure is illustrative only and is not to be taken as limiting, the spirit and scope of the invention being limited only by the terms of the appended claims and their legal equivalents.
Patent Grant
12305350
