FI83982B - Anchoring system - Google Patents

Description

83982

Anchoring system - Förankringssystem 5 UK patent application 2,085,386 A, which has been published, describes a ground anchoring system in which a substantially flat anchor plate is attached to one end of a flexible anchor line and the edge is driven into the ground above with a blow tool.

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When the impact tool is removed and the flexible line is subsequently subjected to lifting forces, the plate tends to settle obliquely across the hole and thus resist detachment from the ground. A somewhat similar device is described in U.S. Patent No. 4,003,169.

In general, this system operates satisfactorily, but it has been found that there is often a significant delay before the plate settles at an angle after the lifting force 20 applied to the line. During this time, the plate may be pulled some distance upwards in the hole, and it is possible that the anchored object will not be firmly anchored to its desired position. This problem is particularly troublesome when objects are anchored to a river or seabed. For example, when a strip mat is anchored to the seabed to prevent bottom erosion under structures such as oil or gas pipelines, any "lifts" applied to the mat after it is anchored can severely impair its subsequent performance under operating conditions.

The object of the present invention is to provide an anchor plate which solves this problem without substantially increasing the resistance of the plate when it is pushed down to the ground.

According to one aspect of the present invention, there is provided a ground anchoring system comprising an anchor plate, the structure of which is described in e.g. U.S. Patent 3,282,002.

In this known construction, the tail flap is locked in its position in the plane of the anchoring plate by a separate latch 5 which holds the tail flap in this level position of the anchoring plate when the anchoring plate is struck to the ground. The locking latch must be opened by a separate mechanism arranged by the handles.

The object of the present invention is to provide an anchor plate which solves the problems associated with the previously known solutions without substantially increasing the resistance of the plate when it is pushed down to the ground.

According to one aspect of the present invention, there is provided a ground anchoring system comprising an anchor plate having a transverse slot arrangement for receiving and securing one end of a flexible anchoring strap or strap projecting from the plate 20 upwardly for connection to an object to be anchored, a protruding tail flap is held in its extended position where it causes the least resistance when the disc is pressed into the ground. The anchoring system is characterized in that the plate includes a sleeve for releasably receiving the impact tool 25 so that the plate remains substantially parallel to the tool when the edge of the plate is pressed forward into the ground; that the protruding tail flap is held in its extended position by the impact tool and released from its extended position to resist upward movement of the plate in the opposite direction when the impact tool is removed and the anchoring strap is tightened.

The protruding portion of the anchor plate preferably extends rearwardly from the rear edge of the plate. In its upward position, the extension 35 is entirely parallel to the plate, the angle generally being in the range of 0-15 ° and preferably less than 10 °. Thus, it provides a minimum resistance to the downward movement of the plate 3 83982 le to the ground. In the released position, on the other hand, the angle increases and is usually in the range of 20-60 °, with the recommended range being 30-45 °.

5 The increased angle brings the trailing edge of the extension into contact with the side of the hole formed in the downward movement of the plate, causing the plate to pivot about this trailing edge across the hole as the anchor line is tensioned.

The extension is preferably resiliently biased to its neutral position, but may alternatively fall freely to the neutral position when the impact tool is removed. It may consist of a deformable strip projecting from the trailing edge, or it may be articulated to the trailing edge. In either case, it is held in its up position by the part of the impact tool cooperating with it so that it is automatically released when the tool is removed.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a front view of an anchor plate fitted with an anchoring strap; 25

Figure 2 is a side view of the plate and belt;

Figure 3 shows the plate when it is driven into the ground with an impact tool; and 30

Figure 4 shows the oblique position of the plate when the belt is later tensioned after the plate is grounded.

Reference is first made to Figures 1 and 2, in which a substantially flat wedge-shaped anchor plate 10 has two slots 11, 12 for attaching a flexible anchoring strap 13. The loop end of the belt 13 is pushed (as seen in Figure 1) backwards from the lower slot 12 and then fed back from the upper slot 11. The loop end is attached to a split elongate retaining ring 14 which prevents the belt from being pulled out of the slots.

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An elongate plug 15 is welded to the front side of the plate 10 for attaching an extended impact arm 22 (Figure 3) of a hydraulic impact hammer (not shown) so that the front edge 30 of the plate can be pressed down into the ground. As shown in Figure 3, the arm 22 fits into the plug with a loose push fit and keeps the plate 10 parallel to the arm in a substantially vertical direction when the plate is ground.

15 A lip 17 extends backwards from the rear edge 18 of the plate 10.

A longitudinally split hollow tube 19 is welded to the trailing edge 18 and is pivotally mounted on a shaft 20 fixed to the center portion 21 of the spout. It is resiliently biased by the spring 23 to the position shown in full lines in Figure 2, the angle 2 being about 40 '. The second extreme position is shown in Figure 2 by dotted lines, with the angle 1 being about 5 '.

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Figures 3 and 4 illustrate the operation of the system. The object to be anchored (not shown) is attached to the upper end of the strap 13. The percussion arm 22 of the impact hammer is then inserted into the plug 15. To insert the arm into the plug, the articulated cap 17 must first be pivoted back against its resilient bias to the up position, shown in full lines in Figure 3. When the arm 22 is then inserted into the plug 15, it holds the tab in its tuned position against the spring bias, the arm conforming to the recess 31 (Figure 1) at the rear edge of the tab.

Thereafter, the plate 10, the belt 13 and the arm 22 are hammered into the ground with a hammer, the retaining plug 15 of the arm 22 keeping the plate parallel to the arm, usually in a vertical position, as shown in Fig. 3.

5 When the plate and belt have been squeezed to the desired depth, e.g.

1-2 meters, the arm 22 is removed from the plug 15 and the lip 17 automatically springs to the position shown by the dotted lines in Figure 3. In this position, the toothed rear edge of the magazine digs into the side of the hole 25 and in this way resists the opposite upward movement of the plate. In addition, it immediately provides a fulcrum around which the plate 10 is forced to pivot into the oblique position shown in Figure 4, the lifting forces subsequently tightening the belt 13. This action ensures that the plate locks immediately in its oblique position and cannot be pulled out of the hole.

The center of gravity of the plate 10 is positioned above the lower slot 12 so that the plate tends to pivot in the direction indicated by the arrows in Figure 4 as the arm 22 is removed from the plug 15. This aids in forcing the serrated edge 24 of the lip 17 to engage the side 25

In addition, the short pin 26 welded to the ring 14 separates the belt 25 from the rear surface of the plate 10, so that as the belt 13 tightens, additional torque acts in the direction of the arrows in Fig. 4. In practice, the forces applied to the plate usually cause it to turn to a horizontally locked position as the rear edge 24 of the lip 17 further digs to the side of the hole.

Claims (5)

6 83982 A ground anchoring system comprising an anchor plate 5 (10) having a transverse slot arrangement (11, 12) for receiving and securing one end of a flexible anchoring strap or strap (13) projecting from the plate upwardly for connection to an object to be anchored; a tail flap (17) 10 retained in its extended position where it causes the least resistance when the plate is pressed into the ground, characterized in that the plate (10) includes a sleeve (15) for releasably receiving the impact tool (22) so that the plate remains substantially with the tool; in the transverse direction, the edge (30) of the plate is driven above the ground; that the protruding tail flap (17) is held in its extended position by the impact tool (22) and released from its extended position to resist the upward movement of the plate in the opposite direction when the impact tool is removed and the anchoring strap is tightened. Ground anchoring system according to Claim 1, characterized in that the tail flap (17) is in its extended position at an angle of 0 to 150 ° to the plate (10) and in its released position at an angle of 20 to 60 °. Ground anchoring system according to claim 2, characterized in that the former angle is in the range of 0 to 10 ° and the latter angle is in the range of 30 to 45 °. Ground anchoring system according to one of the preceding claims 1 to 3, characterized in that the tail flap (17) is held in its extended position against the spring load. Ground anchoring system according to one of the preceding claims 1 to 3, characterized in that the tail flap (17) falls freely from its extended position. 5