AU2004101030A4 - Brick wall clip-on anchor - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT BRICK WALL CLIP-ON ANCHOR The following statement is a full description of this invention including the best method of performing it known to me.

O BRICK WALL CLIP-ON ANCHOR In the field of providing anchors for the attachment of brackets and the like to brick walls, the traditional method is to use countersunk inserts (usually metal or plastic).

For many light-duty, non-critical applications, that method is over-kill and has various drawbacks: The fitting of such inserts involves the use of special tools (e.g.

masonry drills), requires a degree of skill, takes time to apply and is not suitable for later rearrangement as it leaves the wall permanently defaced.

This problem has been addressed by others and two different existing solutions will be described as a way of typifying the existing art: The first example is marketed as BRICK CLIP®, (US Patent 4337915). This is essentially a clip made from a strip of flat spring- steel bent at each end to form hooks which are able to lock into the top and bottom (raked) mortar recesses of an individual brick of the wall. The clip has tabs pressed outwards to facilitate the hanging of items such as pictures, plants, Christmas lights etc. It is low cost, easy to apply and remove and doesn't damage the wall.

The second example is marketed as Bracketmaster®, Australian PCT 749827).

This is essentially a hinged system of two rigid members, one end of each member locating in the top and bottom (raked) mortar recesses of a brick. One member extends outwards to provide a hanging support for an object such as a pot plant. The weight of the object acts through the extended member as a lever to provide a tight clamping action on the brick via the hinge system. It is more expensive than the BRICK CLIP®, but is very easy to mount or remove and doesn't damage the wall. It does, however, rely on the weight of the hung object to achieve clamping pressure and as such is not suitable for totally horizontally-acting loads.

A brick wall clip-on anchor in accordance with this invention comprises spring- wire wound preferably as a single- turn flat spring with the start and finish of the loop projecting tangentially as straight "arms" in almost opposite directions with each "arm" terminating tangentially into an approximately semicircular hook in the same plane as the central loop but facing away from it, proportioned such that the hooks can be located in the upper and lower (raked) mortar recesses of a brick by extending the central spring. The central spring itself, becomes the attachment hole for the object to be supported.

2

O

It can be seen that this invention takes the same approach as the first example of aprior art described in that it is a low cost, spring clip- action device that exerts a clamping action on the brick prior to attachment of subsequent load.

This invention offers the following additional features making it an attractive alternative to prior art known to me: SThe configuration allows loads to be applied from vertically above, below, straight 0 out from the wall or in any direction in between.

OThe configuration provides a more positive grip. For example, a downwardly applied load bears on the bottom of the central loop and so tightens the grip of the top hook but it does not directly place a detaching load on the bottom hook. Spring Opre-load is retained on the bottom hook right up until applied load is sufficient to cause the top hook to yield. Loads applied horizontally outwards try to shorten the distance between the hooks, thus tightening their grip.

The configuration allows for large tolerance in the brick dimension. (This is necessary.) The standard house brick in Australia, having a nominal (face) height of 76mm is allowed to vary from 74mm to 78mm taken as the average variation measured over 20 bricks. Individual bricks may exceed that tolerance considerably.

The wire construction results in high point loads of the hooks at the point of contact with the brick providing a degree of "self-embedding" of the points, enhancing the grip. Note that this embedding occurs in the zone of the raked recess and is visually unobtrusive in the event of relocation. The embedding can be enhanced intentionally simply by "waggling" the fitted anchor from side to side. This may be desirable when the user wants added security, for instance when tethering an animal or suspending a clothes- line.

In preferred use, the anchor would be fitted to a brick wall by firstly locating the bottom hook in the lower mortar recess and then pushing the bottom of the loop upwards and inwards to engage the top hook in the upper recess. No tools are required to fit the anchor. However removal is slightly more difficult. The simplest way is to pull the lower hook downwards and outwards. This may require the use of pliers or if unavailable, a knife point or similar can be used to lever the hook away from the brick.

Applications for this anchor include the following: Attachment of brackets, hooks or wires for hanging plants, attachment of garden hose reels, attachment of brackets for shelves, hanging of bird-cages, pictures, signs, Christmas lights, and tethering applications such as clothes- lines and animal leads.

3 In preferred arrangement, the anchor would be made from round spring steel wire, o galvanized or preferably stainless steel to ensure no staining of brickwork over a Slong period of time. The wire size is chosen mainly to suit the load expected in service. A diameter of 2mm appears to be a good compromise for domestic and commercial applications. Anchors of this size can support a load of 20kg slowly applied horizontally or vertically, under controlled conditions. (Assignment of a recommended "safe load" becomes a separate issue complicated by uncontrollable local conditions and can depend on the particular configuration of the object being Cc supported.) A heavier duty version may have application in workshops and factories, using for instance, 3mm spring steel wire. In such cases, it would be proposed that shallow holes be bored in the mortar recess at an angle of about 45degrees to accept the ends of the hooks. This greatly adds to the reliability. The strong spring of such Sheavy- duty anchors can make it difficult to install. Using "vice-grips" to compress the spring loop overcomes this problem. Alternatively, having two or more turns on the loop instead of one is a method of making the spring more pliable for installation without the use of "vice-grips".

The diameter of the central spring loop needs to be large enough to give sufficient flexibility to span the dimension tolerance of bricks and still impart sufficient preload on the smallest size expected. Consideration is also given to keeping the loop small enough so as not to be unsightly. The anchor using 2mm wire described above has a loop typically 18mm ID. This diameter could be reduced by using two or more turns instead of one.

The diameter of the (approximately) semicircular end hooks is selected to allow good location within the mortar recess. An inside diameter of 8mm works well.

The tangential lead-in and lead-out "arms" from the spring loop are not exactly in line prior to mounting the anchor. In the relaxed condition they are at an included angle typically of 160 degrees on the side opposite the spring loop. In this relaxed condition, the spacing of the hook points is made to be about 68mm. (Considerably less than the 74mm lower tolerance brick so as to ensure pre-load on even smaller bricks.) When the anchor is expanded on fitting to a 78mm upper tolerance brick, the "arms" straighten out to approximately 180 degrees. This allows for maximum horizontal penetration of the hooks into the mortar recesses.

(Note: The above dimensions are based on the standard Australian house brick with 76mm nominal face height. The general design of this anchor can be applied to any size of brick or even wooden beams. The proportions of the anchor would have to be varied to suit.) 04 All the foregoing relates to an anchor having the spring loop in the vertical o plane (axis horizontal) when the anchor is fitted to a wall. This is largely a Smatter of simplicity of design and ease of manufacture.

In some circumstances, depending on the detail of the object being supported, it may be more convenient to have an alternative configuration with the central loop in the horizontal plane (axis vertical). This configuration will be referred to here as a "helical spring" type. Such an anchor does not need the lead-in and lead-out "arms" to be at a preset angle but must have at least 2 turns in the spring loop. This is because a single turn in the horizontal plane allows weight hung on it to disengage the bottom hook from its point of Scontact in the brick recess. Having at least 2 turns means that the weight is taken on the upper turn and pre-load tension in the remainder of the spring keeps the hook in contact. Note that whatever is attached to the spring loop must pass through all turns and so a horizontally applied load will try to pull the turns into close proximity and shorten the distance between the hooks, increasing the grip on the brick. The proportions of this type of anchor may need to be slightly different to those of the flat spring type.

The invention may be better understood with reference to the illustrations of the embodiments of the invention which: Figure 1 is a perspective view of a flat spring style of anchor made with a single- turn center spring 1, in the relaxed condition before mounting on a wall. Center spring 1 is in the same (vertical) plane as the end hooks 2. In this relaxed condition, the lead-in and lead-out "arms" 3 are inclined at an angle to each other.

Figure 2 shows a flat spring style of anchor made with a two-turn (as example) center spring 4 in the relaxed condition prior to mounting.

Figure 3 shows a flat spring style of anchor mounted on a brick wall 5 and indicates the end hooks located in the raked mortar recesses 6 and with the "arms" 3 now in an almost straight line.

Figure 4 is a view in perspective of a helical spring style of anchor made with a 2-turn (as example), close-wound center spring 7, in the relaxed condition prior to mounting on a wall. The center spring 7 is in the horizontal plane at degrees to the plane of the end hooks and the arms 8 are in a straight line and vertical.

Figure 5 shows the helical spring type mounted on a brick wall with the center spring now expanded to allow the end hooks to locate in the mortar recesses.

Claims (3)

1. 2. A brick wall clip-on anchor as claimed in claim 1, wherein the spring is wound with two or more turns.
2. 3. A brick wall clip-on anchor as claimed in claim 2, wherein the spring has it's C, axis parallel to the "arms" and wherein the "arms" are in a straight line.
3. 4. A brick wall clip-on anchor according to any claims 1, 2 and 3 wherein the spring wire is galvanized steel or stainless steel of round, square or rectangular section. A brick wall clip-on anchor substantially as herein before described with reference to figures 1 to 5 of the accompanying drawings. ANTHONY DAVID MOSES 6 DECEMBER 2004