AU680352B2 - Ground anchors - Google Patents

Description

1

AUSTRALIA

Address for Service RANT ADAMS COMPANY, Level Patents Act 19 de90 arkAttorn invention including the best method of performing it known to me.

known to me.

~b~L~e IliB~ THIS INVENTION relates to ground anchors. In particular, the invention relates to methods of manufacturing ground anchors, and the anchors produced by the methods.

Throughout the specification, the term "ground anchors" shall be used to include "helical piers" and "screw piers".

Ground anchors which incorporate helical flytes or screws, to enable the anchors to be driven into the ground, are well-known (see US 5,046,699 (Perreault); US 4,593,872 (Svensson); 3,011,597 (Galloway) and US 1,831,678 (McCallen).

The present methods for manufacturing such anchors usually include the steps of: 15 forming the helical flyte or rib from an annular metal plate; S(2) welding the flyte or rib to the anchor shank; and galvanising the anchor (for long service life).

It is an object of the present invention to provide a method of forming the anchors where the helical flyte or rib is formed from the tubulai shank.

It is a preferred object to provide a method where the anchors can be formed from galvanised steel.

It is a further preferred object to provide a method where sockets and spigots can be formed at respective ends of the shanks to enable the anchors to be easily connected together, eg. in a string.

Other preferred objects will become apparent from the following description.

In one aspect, the present invention resides in a method of manufacturing a ground anchor (as hereinbefore described) including: forming at least one elongate slit in a II-- ~l IC ~41 tubular wall of a shank for the anchor; engaging respective upper and lower dies with the tubular wall above and below the slit(s); and urging the dies towards each other to cause the portion of the tubular wall between the dies to be deformed outwardly to form a helical flyte or rib about the shank.

In a second aspect, the present invention resides in a method of manufacturing a ground anchor (as hereinbefore defined) including: expanding a portion of a tubular wall of a shank for the anchor into an external die to form a "bell" about the shank; forming an elongate slit in the bell; engaging respective upper and lower dies with the tubular wall and/or bell above and below the bell; and urging the dies towards each other to cause a portion of the bell between the dies to be S 20 deformed to form a helical flyte or rib about the shank.

Preferably, the bell is formed by placing an *inflatable (eg. rubber) insert within the shank and inflating the insert to deform a portion of the tubular wall into the external die.

25 Preferably, the upper and lower dies have complementary faces which deform the tubular wall or bell into the formation of the helical flyte or rib.

In third and fourth aspects, the present invention resides in ground anchors (as hereinbefore i 30 defined) formed by the methods of the first and second aspects, respectively.

Preferably, a socket is formed at the upper end of the shank, and a complementary spigot is formed at the lower end of the shank, to enable the ground anchors to be connected together; the socket also allows fiArr -~AaRa 4 engagement by an anchor driving machine and/or a fitting to receive a post or the like.

To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which: FIGS 1 to 6 show the steps of a first method; and FIGS 7 to 11 show the steps of a second method.

Referring to FIG 1, the ground anchor 10 is formed from galvanised steel (eg. 65mm diameter, 3.6mm wall thickness) with a tubular shank.

"An elongate slit 12 is formed in the shank 11, a parallel to the axis 13 of the shank.

Upper and lower dies 20, 21 are engaged with the shank 11 adjacent the ends of the slit 12 and they .have respective die faces 22, 23 which are helical in form (see FIG 2) As shown in FIGS 3 and 4, the dies 20, 21 are advanced towards each other (ie. one or both dies may be 20 moved) and the portion la of the shank 11 between the Os dies becomer outwardly deformed into the helical flyte 14 0. shown in FIGS 5 and 6. As shown in FIG 6, the thickness *0 of the helical flyte 14 is approximately double the wall S" thickness of the shank 11 and the helical flyte 14 has been cold (or hot) formed from, and integrally with, the shank 11.

*o To complete the anchor 10, a square/hexagonal/octagonal socket (not shown) may be formed (by dies) at the upper end of the shank 11; and a complementary spigot (also not shown) may be formed at the lower end.

The spigot can engage the socket of another anchor 10 to enable the anchors 10 to be connected into I i p~-e y a string and/or form a digging point for the (lowermost) anchor. The socket can be engaged by an anchor drive tool and/or receive a fitting to support a post, reg or the like.

Referring now to FIGS 7 and 8, an outer die (not shown) is placed around the shank 111 of anchor 110 and an infl2table insert (not shown) is placed in the shank 111, aligned with the outer die. The insert is inflated and a portion 111 is expanded outwardly to form a "bell" Ila.

After the insert and outer die are removed, an S elongate slit 112 is formed in the bell lila (see FIG 9).

Top and bottom dies 120, 121 engage the shank 15 111 and/or bell llla (FIG 10) and are moved towards each other (FIG 11) to form the helical flyte about the shank 111 (as in FIGS 5 and 6).

The socket and spigot are then formed as hereinbefore described.

As the shank 11, 111 is of galvanised steel, galvanising of the completed anchors 10, 110 is not required. Similarly, the helical flyte is not separately formed and welded to the shank.

The present invention provides a simpler, more efficient method of manufacture, which results in a superior product.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention defined in the appended claims.

ll~e~lll

Claims (9)

1. A method of manufacturing a ground anchor (as hereinbefore defined) including: forming at least one elongate slit in a tubular wall of a shank of the anchor; engaging respective upper and lower dies with the tubular wall above and below the slit(s); and urging the dies towards each other to cause the portion of the tubular wall between the dies to be formed outwardly to form a helical flyte or rib about the shank.

2. A method of manufacturing a ground anchor (as hereinbefore defined) including: expanding a portion of a tubular wall of a shank of the anchor into an external die to form a "bell" about the shank; forming an elongate slit in the bell; engaging respective upper and lower dies with the tubular wall and/or bell above and below the 9 S 20 bell; and urging the dies towards each other to cause a portion of the bell between the dies to be deformed to form a helical flyte or rib about the shank.

3. A method as claimed in Claim 2 wherein: the bell is formed by placing an inflatable insert within the shank and inflating the insert to deform a portion of the tubular wall into the external die.

4. A method as claimed in any one of Claims 1 to So 30 3 wherein: the upper and lower dies have complementary faces which deform the tubular wall or bell into the for-iation of the helical flyte- or rib.

A ground anchor (as hereinbefore defined) formed by the method of any one of Claims 1 to 4. i IIIII~ bPIII~C ~-I

6. A ground anchor as claimed in Claim 5 wherein: a socket is formed at an upper end of the shank, and a complementary spigot is formed at a lower end of the shank to enable a plurality of the ground anchors to be connected together.

7. A ground anchor as claimed in Claim 6 wherein: the socket allows engagement by an anchor driving machine and/or a fitting to receive a post or the like.

8. A method of manufacturing a ground anchor (as hereinbefore defined) substantially as hereinbefore described with reference to FIGS 1 to 6; or FIGS 7 to 11, of the accompanying drawings.

9. A ground anchor (as hereinbefore defined) formed by the method of Claim 8. DATED this seventh day of April 1997. PAUL ANTHONY CAMILLERI, SBy his Patent Attorneys, FISHER ADAMS KELLY. oe *0 0* 00 a i -pnn I I tf 8 ABSTRACT A method of manufacturing a ground anchor 110) where an elongate slit (12, 112) is formed in the tubular shank (11, 111); and dies (20, 21, 120, 121), engaging the shanks (11, 111) are moved towards each other to deform the tubular shank (11, 111) therebetween into a helical flyte or screw (14, 114). In an alternative embodiment, the shank (11, 111) may have a bell (11a) formed therein before the slot (12, 112) is formed and the dies (20, 21, 120, 121) are engaged and operated. *e 6 4. o 0 a. a f cl I~ra~