Field of the Invention

The invention relates to the problem of supporting a wall in w hich an opening is to be cut and where the size and/or loca¬ tion of the opening is such that it might be risky to leave the region of wall above the intended opening unsupported for any appreciable length of time .

State of the Art as known to the Applicant

Cutting an opening into an existing wall to fit a door or window , or simply to open up two rooms into one via an archway , is common practice in these days of home improvement . The original wall of course was not intended to be weakened in this way . It is therefore almost always necessary to support the roof of the new ly-created arch opening by a lintel before plastering and making good around the edges of the opening . The lintel is embedied into the remainder of the wall , beyond each opposite side of the new opening , and supports the region of wall above the opening from then on.

There are many circumstances in which it might be risky to leave that region of wall above the opening unsupported for any appreciable length of time , before the lintel can be put into place . The time of greatest risk is immediately after the opening has been cut , the previously-infilling material removed from it , and the region above the opening is temporarily

without any vertical support .

Conventional wisdom dictates that the builder should work as fast as possible to insert the lintel , taking the risk that the temporarily-unsupported wall can be relied on to hold up for the relatively short time that it has to . But how ever accept¬ able this risk in practice , it is still a risk and it would be better eliminated .

Summary of the Invention

The invention, which may be embodied in a method or an appa- ratus , involves putting a sufficiently large part of the region of wall above the intended opening into compression across its thickness , and supporting the compressing means by a prop braced against the ground or floor from which the wall rises .

To the best of the applicant ^' s knowledge , this is new . It also involves an inventive step insofar as there is nothing in the state of the art, method or equipment to suggest the invention. And it has the clear advantage of removing entirely the risks reviewed above when, again, conventional thinking has been perfectly prepared to accept those risks for very many years and so the problem now solved by the invention remained quite unrecognised until now .

Preferably there are two props positioned one adjacent each opposite face of the wall . It is possible to put the invention into practise using only one prop and a frictionally-tightening means - for example , a nut and bolt or a cable and tensioner means - passing through the wall to apply the necessary com¬ pression to the wall . But the same effect can be achieved , without any such means , if two props are braced between the ground or floor and one respective face of the wall and so act in opposition on the wall thickness .

It is advantageous if the main portion of the or each prop can be positioned sufficiently far from the adjacent wall face that the person subsequently cutting the opening can work with his body positioned between the wall face and the prop . One embodiment of the invention in which this is done is described in this specification with reference to the accompanying drawings .

It is also advantageous , not least in achieving the object out¬ lined in the preceding paragraph , if the prop - or at least one of the props if there are more than one - rises from the ground or the floor substantially vertically . Here again, the presently preferred embodiment of the invention incorporates this feature and will now be described with reference to the drawings .

Brief Description of the Drawings

The drawings comprise a single diagrammatic Figure which is not intended to be drawn to any precise scale and nor is it intended to limit the scope of the invention which is defined in the claims at the end of this specification.

Description of the Preferred Embodiment

In the drawing , an existing brick-built plaster-faced internal wall 11 of a house is shown across its thickness , i . e . in cross- section. The construction of the wall is straightforward and forms no essential feature of the present invention.

An opening , to take a standard door ( i . e . approximately 6 ft 3 inches by 2 ft 6 inches ) is to be cut into the wall . The opening or arch thus created in the wall will have a roof 12 beneath w hich the region of wall 13 above the opening is unsup¬ ported for as long as it takes to brace appropriately the new ly- created opening with a wooden or steel lintel 14.

To support the wall , and before the opening 15 is cut from it , a prop 16 is brought into position and is spaced sufficiently far from the adjacent face 17 of the wall for a user , cutting the opening , to work with his body positioned between the wall face 17 and the prop 16.

For the same reason, a rigid arm 18 which projects from the end of the prop 16 is sufficiently high from the ground 19 from which the wall rises that the subsequent opening-cutting person can work comfortably beneath the arm 18.

The prop 16 is height-adjustable , in known manner , so that the arm 18 can be positioned at this desired height. The arm 18 is rigidly connected to the end of the prop 16 and protrudes essentially at right angles from the axis along which the prop 16 extends and retracts to vary its overall length .

A rigid steel plate 21 of appreciable thickness is welded to that end of the arm 18 remote from the prop 16. The plate 21 extends substantially at right angles to the axis of the arm 18 and hence is substantially parallel with the axis of the prop 16.

The plate 21 is drilled so that a threaded rod 22 can pass through it. The rod 22 , in use , also passes through an appro¬ priately sized hole which has been drilled in the wall 11 , again before any cutting of the opening 15 has taken place .

The prop 16 is positioned as illustrated so that it rises vertically from the floor 19 and so that the plate 21 abuts the adjacent face of the wall 11. The threaded rod 22 goes through the hole in the plate 21 , and through the wall 11 , to emerge from the opposite face . Each opposite end of the rod 22 is threaded so that a respective co-operating nut such as the nut 23 can hold the rod captive .

The illustrated components , which are shown only on one face 17 of the wall , are repeated mirror-image-wise on the other face 24. Thus there will be another prop carrying another arm which in turn carries another plate , which like the plate 18 abuts the face 24 and from which a threaded end of the rod 22 emerges to be held captive by a nut like the nut 23.

Both nuts are then tightened to put the wall into compression across its thickness . This , together with the rigid nature of the two props , ensures that the opening 15 can then but cut out of the wall 11 with safety . When the previously-infilling material from opening 15 is removed , the props , plates , and tightened rods will support the region 13 for as long as is necessary to insert and bed in the lintel 14.