GB2156756A

GB2156756A - Improvements in anchors

Info

Publication number: GB2156756A
Application number: GB08408511A
Authority: GB
Inventors: William Frank Spanner
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-04-03
Filing date: 1984-04-03
Publication date: 1985-10-16
Also published as: GB8408511D0; GB2156756B

Abstract

An anchor comprising a generally planar frame (12) which can be in the form of an equilateral triangle with a first fluke (16) fixedly secured by first mounting means (20) to the frame on one side of the plane thereof and a second fluke (18) fixedly secured by second mounting means (22) to the frame on the other side of the plane thereof. The anchor also includes means (24) for securing the frame to an anchor line, the fixing positions of the mounting means at the frame and the securing means being at or near the vertices and apex respectively of an isosceles triangle. <IMAGE>

Description

SPECIFICATION Improvements in anchors This invention relates to anchors.

There is a requirement for a boat anchor which can be raised and lowered easily and which is effective in use with various types of seabed such as sand, clay, rock and the like.

According to the invention there is provided an anchor comprising a generally planar frame, a first fluke fixedly secured by first mounting means to the frame on one side of the plane thereof, a second fluke fixedly secured by second mounting means to the frame on the other side of the plane thereof and means for securing the frame to an anchor line, the fixing positions of the mounting means at the frame and the securing means being at or near the vertices and apex respectively of an isosceles triangle.

The frame may be in the form of a generally isosceles triangle with the said fixing positions and securing means at or near the base vertices and the apex of the triangle respectively.

The flukes may be substantially flat.

Preferably, the flukes are so orientated that their planes are at an acute angle to the plane of the frame, diverging from the frame in the direction from the mounting means towards the securing means.

The flukes may be generally triangularshaped but with two curved sides, the apex therebetween being directed towards the securing means.

Preferably the flukes are mounted asymmetrically on the mounting means.

By extending the mounting means auxiliary flukes generally similar to but smaller than the main flukes, may be arranged on the opposite sides of the frame.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a plan view of one embodiment of an anchor according to the invention; Figure 2 is a side view of the anchor of Fig.

1; Figure 3 is a diagrammatic side view of an anchor according to Fig. 1 in use on a relatively soft, sandy seabed; Figure 4 is a diagrammatic side view of an anchor according to Fig. 1 in use on a relatively hard, rocky seabed.

Figure 5 is a side view of another embodiment of an anchor according to the invention.

Referring to the drawings, there is shown an anchor 10 comprising a frame 1 2 in the form of an equilateral triangle manufactured from strips 1 4a, 1 4b, 1 4c of mild steel welded together galvanised, or rustproofed.

First and second flukes 16, 1 8 are fixedly secured, as by welding to mounting pillars 20, 22 respectively which are, in turn, fixedly secured to the frame 12; the fluke 1 6 being on one side (the upper side in Fig. 2) of the plane of the frame 1 2 and the fluke 1 8 being on the other side.

The pillars 20 and 22 are positioned substantially at the vertices between sides 14a, 1 4b and 14a, 1 4c respectively. Formed at the vertex, or apex between sides 14b, 1 4c is an aperture or towing eye 24 for use in securing the anchor 10 by way of a shackle to an anchor chain or cable (not shown).

The flukes 16, 1 8 are substantially flat and of generally, scalene triangular shape although it will be seen that the two curved sides 16a, 1 6b and 18a, 1 8b of each fluke are curved outwardly. This makes the anchor 10 easier to handle. The sides 16c, 1 8c can be straight.

The sides 16b, 1 8b are longer than sides 16a, 1 8a and the flukes 16, 18 are mounted asymmetrically on the pillars 20, 22 respectively with their apices directed towards the aperture 24.

The flukes 16, 1 8 are so orientated that they subtend an acute angle to the plane of the frame 1 2 in such a direction that they diverge away from the frame in a direction towards the aperture 24, typical values of being between 15 and 45 .

The dimensions of the frame 12, flukes 16, 1 8 and pillars 20, 22 may be determined empirically or mathematically to suit the vessel and the conditions. In one embodiment, the sides of the frame 1 2 are about 30cm long and 5cm wide and 0.8cm thick; the pillars about 13cm long and 2cm diameter; the flukes about 13cm along sides 16c, 18c, 15cm along a line taken normal to base sides 16c, 1 8c to the corresponding apex with the normal line bisecting the base 16c, 1 8c at a position about 8cm from the vertex between sides 16b, 16cand 18b, 18c.

Figs. 3 and 4 show the anchor 10 in use in soft sand and on a hard, rocky surface respectively.

Referring to Fig. 3, it will be seen that the lower fluke, in this case fluke 18, has sunk into the sand 26 dragging the frame 1 2 with it, but the upper fluke 1 6 is resting on the surface of the sand and tends to reduce the tendency for the anchor to sink deeper into the sand 26. This makes it easier to break-out and raise the anchor when required.

Also by securing the plane of the fluke 18 at an angle to the plane of the frame 12, as shown, this improves the anchoring properties of the anchor 10 as it is dragged along the surface of the seabed 28 by an anchor chain secured to aperture 24.

Referring to Fig. 4, this shows the anchor 10 on a firmer sea bed 30 when the apex of the lower fluke 1 8 would tend to dig-in the sea bed as the anchor is dragged.

To improve the grip of the anchor 10 on firmer surfaces, it is possible to secure spurs, shown in phantom at 32, on the uppersides or undersides of the flukes 16, 18.

Such an anchor as described is unlikely to snag under rocks or the like, but it is provided with an aperture 34 to which a line can be attached. In the event that the anchor 10 is snagged it can be pulled by the line attached to aperture 34 in a direction opposite to the original direction of pull due to the anchor chain or cable attached to aperture 24 thereby to release the anchor.

Fig. 5 shows a side view similar to that of Fig. 2 of another embodiment of an anchor according to the invention provided with aux iliaryflukes 17, 19, mounted on pillars 21, 23 as shown.

Thus there has been described an anchor which can: 1. give good holding power on different types of seabed.

2. be safely and comfortably manhandled.

3. be easily raised and lowered and restrained from sinking deeply into soft seabeds by the upper fluke.

4. be easily broken out prior to raising.

5. be used on small vessels where raising and lowering of the anchor may be required to be carried out at fairly frequent intervals, for example, when fishing or sailing short distances.

Claims

1. An anchor comprising a generally planar frame, a first fluke fixedly secured by first mounting means to the frame on one side of the plane thereof, a second fluke fixedly secured by second mounting means to the frame on the other side of the plane thereof and means for securing the frame to an anchor line, the fixing positions of the mounting means at the frame and the securing means being at or near the vertices and apex respectively of an isosceles triangle.

2. An anchor according to claim 1, wherein said frame is in the form of a generally isosceles triangle with said fixing positions and securing means at or near the base vertices and the apex of the triangle respectively.

3. An anchor according to claim 1 or 2, wherein each fluke is substantially flat.

4. An anchor according to claim 3, wherein the flukes are so orientated that their planes are at an acute angle to the plane of the frame, diverging from the frame in the direction from the mounting means towards the securing means.

5. An anchor according to any one of the preceding claims, wherein each fluke is generally triangular-shaped but with two curved sides, the apex therebetween being directed towards the securing means.

6. An anchor according to any one of the preceding claims, wherein the flukes are mounted asymmetrically on the mounting means.

7. An anchor according to any one of the preceding claims, wherein auxiliary flukes generally similar to but smaller than the first mentioned flukes are arranged on opposite sides of the frame.

8. An anchor according to any one of the preceding claims, wherein a spur is fitted to the upperside or underside of each of the first mentioned flukes.

9. An anchor substantially as hereinbefore described with reference to Figs. 1 to 4 or Fig. 5 of the accompanying drawings.