WO1992014935A1

WO1992014935A1 - A fastener anchor

Info

Publication number: WO1992014935A1
Application number: PCT/GB1992/000327
Authority: WO
Inventors: Peter Kelvin Fowler; Terence Robert Fowler; David Geoffrey Jenman; Charles Henry Ryland
Original assignee: Peter Kelvin Fowler; Terence Robert Fowler; David Geoffrey Jenman; Charles Henry Ryland
Priority date: 1991-02-25
Filing date: 1992-02-24
Publication date: 1992-09-03
Also published as: GB9103859D0; AU1275492A

Abstract

A fastener anchor (2) comprising a head (12), a body portion (6), an external thread (8) on the body portion (6), and a pair of slots (10) which extend longitudinally of the body portion (6) and which also extend towards each other from opposite sides of the body portion (6).

Description

A FASTENER ANCHOR

This invention relates to a fastener anchor.

Fastener anchors are well known and they are usually employed for enabling fixings to be made in friable sheet material such for example as plasterboard. The friable sheet material may form walls, partitions or ceilings. The known fastener anchors are often not satisfactory in that they are expensive to produce and/or require a bore to be drilled in the sheet material to which they are to be fixed and/or they do not form a sufficiently good anchor into which a threaded fastener such as a threaded screw or a threaded bolt can subsequently be fixed.

It is an aim of the present invention to provide a fastener anchor which reduces the above mentioned problems.

Accordingly, in one non-limiting embodiment of the invention there is provided a fastener anchor comprising a head, a body portion, an external thread on the body portion, and a pair of slots which extend longitudinally of the body portion and which also extend towards each other from opposite sides of the body portion. The external thread on the body portion enables the fastener anchor to be screwed into an appropriate surface without the need to first drill a bore in the surface. When a threaded fastener is screwed into the fastener anchor, the slots allow the body portion to expand, thereby helping to ensure that the fastener anchor remains a firm fit in the surface in which it has been located. If the fastener anchor is used on a cavity structure so that the fastener anchor protrudes through the other side of a piece of sheet material, then the slots in the fastener anchor can enable the fastener anchor to open up on the inside of the sheet material to firmly locate the fastener anchor in position. The fastener anchor can be made of a mouldable plastics material so that it can easily and cheaply be produced.

In a preferred form of the fastener anchor, the fastener anchor is one in which the slots extend past each other, and in which the slots are offset from each other, whereby a membrane member between the slots is created. The slots may extend past each other by, for example, a distance of 3mm,

The slots may be offset from each other by, for example, a distance of 0.25mm.

The presence of the membrane member is advantageous in that it fills up the screw thread of a screw threaded fastener, for example a screw or a bolt, as the screw threaded fastener is screwed into the fastener anchor. Also, the membrane member cooperates with the offset slots to enable the screw threaded fastener easily to be screwed in a straight line along the fastener anchor.

If desired, the fastener anchor may be one in which the slots are in line with each other, and in which the slots stop short of each other. Preferably, the fastener anchor is one in which one slot is longer than the other slot. For example, the longest slot may be 1 mm longer than the other slot. The provision of one slot which is longer than the other slot enables a screw threaded fastener which is longer than the fastener anchor to be screwed through the fastener anchor and to break out of the fastener anchor at a predetermined point. This is because the longest slot tends to form an area of weakness at which the screw threaded fastener is able to break out of the fastener anchor. Although the fastener anchor may be directly driven by a hammer or other object into some material, the fastener anchor will usually be one in which the head includes a formation for enabling the fastener anchor to be screwed into a surface. The formation will usually be a recess. The recess may be a slot for receiving a blade screwdriver, or the recess may be a star-shaped recess for receiving a Phillips or a Pozidrive (trade mark) screwdriver.

Preferably, the fastener anchor is one in which the slots extend in a straight line from the recess to a Position, adjacent a tip of the fastener anchor. In an alternative embodiment of the fastener anchor, the slots extend in a straight line from a position remote from the recess to a position adjacent a tip of the fastener anchor. In a yet further embodiment of the fastener anchor, the fastener anchor may be one in which the slots extend in a straight line towards a tip of the fastener anchor, but then extend to a side of the fastener anchor. The use of slots extending to a side of the fastener anchor helps threaded fasteners which are longer than the fastener anchor to break through the fastener anchor at a predetermin position.

Usually, the fastener anchor will be one in which the tip is a pointed tip. Other tips for the fastener anchor may however be employed.

Where the fastener anchor has a recess, then the recess nay advantageously extend into a dimpled portion forming a lead-in for a threaded fastener. The dimpled portion allows the threaded fastener easily to get a straight start as it is screwed into the fastener anchor. By way of example, it is mentioned that the dimpled portion may be 2mm deep.

The head of the fastener anchor is preferably a flat head so that the head does not project substantially from a surface of a member in whi-n the fastener anchor is located.

The body portion is preferably a tapering body portion. The body portion may however be a parallel sided body portion if desired.

As indicated above, the fastener anchor will usually be made of a plastics material. A presently preferred plastics material is 50% glass filled nylon (registered trade mark). Other types of plastics material such for example as ABS may be employed.

The fastener anchor may be made in a two part mould. Each part of the mould may have a blade for forming one of the slots in the fastener anchor. Preferably the blades are separately formed from the remainder of the mould so that, if a blade should break, it can easily be replaced without having to replace the entire mould.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 is a side view of a first fastener anchor;

Figure 2 is a cross section through the fastener anchor as shown in Figure 1;

Figure 3 shows the fastener anchor of Figure 1 being fitted into a sheet of plasterboard; - o -

Figure 4 is a side view of a second fastener anchor; Figure 5 is a longitudinal section through the second fastener anchor shown in Figure 4;

Figure 6 is a side view of a third fastener anchor; and

Figure 7 is a longitudinal section through the third fastener anchor shown in Figure 6.

Referring to Figures 1 - 3, there is shown a fastener anchor 2 comprising a head 4, a tapering body portion 5, ΞJΩ. external thread 8 on the body portion 6, and a pair of slots 10.

The slots 10 extend longitudinally of the body portion 6 as shown in Figure 1. As shown in Figure 2, the slots 10 also extend towards each other from opposite sides of the body portion 6. The slots 10 extend past each other as shown in Figure 2. The slots 10 are offset from each other, also as shown in Figure 2, whereby a membrane member 12 between the slots 10 is created. By way of example, it is mentioned that the slots 10 may extend past each other by a distance of 3m and the slots 10 may be offset from each other by a distance of 0.25mm.

One slot 10 is slightly longer than the other slot 10. By way of example, it is mentioned that the longest slot 10 is 1 mm longer than the other slot 10. The head 4 includes a formation in the form of a recess 16 for receiving a screwdriver 18, only part of which is shown in Figure 3. The recess 16 is a star- shaped recess 16 for receiving the complementary shaped end 20 of the screwdriver 18.

As can be seen from Figure 1, the slots 10 extend from the end of the recess 16 to a position 22 adjacent a pointed tip 24 of the body portion 6. The tip 24 helps to enable tne fastener anchor 2 initially to pierce the plasterboard 14 and then to be screwed through the plaster¬ board 14 as shown in Figure 3.

When the fastener anchor 2 is fully in position in the plasterboard 14, a threaded fastener in the form of a screw 26 can then be screwed into the fastener anchor 2. The screw 26 has a head 28 which locates in the recess 16 when the screw 26 is screwed fully home into the fastener anchor 2. As the screw 26 is screwed through the fastener anchor 2, it destroys the membrane member 12 and the material of the membrane member 12 wraps around the thread 30 of the screw 26, thus helping to keep the screw 26 a firm and positive fit in the fastener anchor 2. Also, as the screw 26 is screwed through the fastener anchor 22, the screw 26 tends to expand the body portion 6 of the fastener anchor 2 so that the fastener anchor 2 becomes a yet tighter fit in the plasterboard 14. In this connection, it will be under¬ stood that the external thread 8 is a large coarse external thread 8 which in itself gives a good grip in the plaster¬ board 14. It will be noticed that the head 4 is a flat head so that, as can be seen in Figure 3, the head 4 does not project substantially beyond the surface 32 of the plasterboard 14 when the fastener anchor 2 is screwed fully home into the plasterboard 14. The fastener anchor 2 is made of 50% glass filled nylon although it may be made of other plastics materials if desired.

Referring now to Figures 4 and 5, there is shown a second fastener anchor 2 in which similar parts as in Figures 1 - 3 have been given similar reference numerals for ease of comparison and understanding.

_n Figures *- and 5, it will be seen that the slots 1° are shorter than the slots 10 shown in Figures 1 - 3. In Figures «■ and 5, the slots 10 extend in a straight line from a position 34 remote from the recess 16 to a position 36 which is more remote from the tip 24 than the position 22. As can be seen from Figure 5, the slots 10 basically occupy the middle one third of the fastener anchor 2. It will also be noticed from Figure 5 that the recess 16 extends into a dimpled portion 38. The dimpled portion 38 forms a lead-in for the screw 26 and helps to ensure that the screw 26 gets a good straight start as it is screwed into the fastener anchor 2.

In Figures 4 and 5, the slots 10 are of the same length. As mentioned above, in the fastener anchor 2 shown in Figures 1 - 3, one of the slots 10 is slightly longer than the other of the slots 10. This ensures that if the screw 26 is longer than the fastener anchor 2, the screw 26 can bre=_k through the fastener anchor 2 at a predetermined position. More specifically, the longest slot 10 forms a slight area of weakness in the body portion 6 adjacent the tip 24 and this is where the screw 26 breaks through the fastener anchor 2. If the slots 10 are the same length, then a long screw 26 can still break through the fastener anchor 2 but it cannot be predicted on which side of the fastener anchor 2 the screw 26 will break through. As the screw 26 breaks through the fastener anchor 2, the slots 10 cause the body portion 6 to be formed into two diverging parts which form an especially good fixing for cavity wall fixings of the type illustrated in Figure 3 where the fastener anchor 2 projects completely through the plaster¬ board 14. Referring now to Figure 7, there is shown a third fastener anchor 2 and again similar parts have been given the same reference numerals for ease of comparison and understanding. In Figure 7, the slots 10 are of the same length but they have an end portion 40 which extends to one side of the body portion 6 and breaks through the body portion 6 at position 42. If a screw 26 is used which is longer than the fastener anchor 2, the screw 26 breaks through the body portion 6 at the position 42. Figure 7 illustrates how the dimpled portion 38 of

Figure 5 has been formed into a slightly longer parallel- sided bore portion 38.

The fastener anchors 2 of the present invention can easily and cheaply be formed by moulding. The external thread 8 enables them easily to be fixed into the plaster¬ board 14 in a firm and positive manner. Fastener anchors 2 are such that the body portion 6 is basically a solid body portion 6 and the slots 10 are easily formed. The membrane member 12 is useful for giving the screw 26 something to bite on as it screws through the fastener anchor 2 and the destroyed material from the membrane member 12 advantageously fills the threads 30 of the screw 26.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the body portion 6 is shown to be a tapering body portion ό but the body portion 6 could be a parallel sided body portion if desired. The fastener anchors 2 can be inserted into any suitable and appropriate material. The end portion 40 extends at approximately 45° to the main part of the slots 10 but it could extend at any other suitable and appropriate angle.

Claims

A fastener anchor comprising a head, a body portion, an external thread on the body portion, and a pair of slots which extend longitudinally of the body portion and which also extend towards each other from opposite sides of the 5 body portion.

2. A fastener anchor according to claim 1 in which the slots extend past each other, and in which the slots are offset from each other, whereby a membrane member between the slots is created.

10 3. A fastener anchor according to claim 1 in which the slots are in line with each other, and in which the slots stop short of each other.

4. A fastener anchor according to any one of the preceding claims in which one slot is longer than the other slot.

-*t κ 5. A fastener anchor according to any one of the preceding claims in which the head includes a formation for enabling the fastener anchor to be screwed into a surface.

6. A fastener anchor according to claim 5 in which the formation is a recess, and in which the slots extend in a straight line from the recess to a position adjacent a tip of the fastener anchor.

7. A fastener anchor according to claim 5 in which the formation is a recess, and in which the slots extend in a straight line from a position remote from the recess to a position adjacent a tip of the fastener anchor.

8. A fastener anchor according to claim 5 in which the formation is a recess, and in which the slots extend in a straight line towards a tip of ^'the fastener anchor, but then extend to a side of the fastener anchor.

9. A fastener anchor according to any one of claims 6,

7 or 8 in which the tip is a pointed tip, and in which the recess extends into a dimpled portion forming a lead-in for a threaded fastener.

10. A fastener anchor according to any one of the preceding claims in which the head is a flat head so that the head does not project substantially from a surface of a memb which the fastener anchor is located, in which the body portion is a tapering body portion, and in which the fastener anchor is made of a plastics material.