GB2129084A

GB2129084A - Wall fixing

Info

Publication number: GB2129084A
Application number: GB08224120A
Authority: GB
Inventors: Douglas Maxwell Campbell; William Thomas Evans
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-08-21
Filing date: 1982-08-21
Publication date: 1984-05-10
Also published as: GB2129084B

Abstract

A wall fixing, such as a remedial wall tie (or anchor bolt), comprises a rod 1 having threaded ends arranged to grip in bores 2, 2 formed in the inner and outer leaves 3, 4 of a cavity wall, by causing the expansion of cups 10 by means of axial compression. The inner end of the rod 1 is screwed into a nut 6 held in an eccentric washer 7 carrying a spike 8 to prevent rotation of the washer 7 and hence of the nut 6. Expansion of the cups 10 at the inner end of the rod 1 is caused by rotating the outer end 13. The cups 10 at the outer end 13 are expanded by rotating a nut 12. The nut 6 is a lock-nut. <IMAGE>

Description

SPECIFICATION Wall fixing This invention relates to a wall fixing, particularly but not exclusively a tie-bar for cavity walls.

Up to the present, most tie-bars have depended for their effectiveness in gripping the brickwork of a wall on the friction between an expanding rubber (or similar) collar at each end of the tie-bar, and the interior surface of holes drilled in the brick work to accept the tie-bar. Unfortunately, this type of arrangement may lose its effectiveness because collar material may degrade due to dampness and ageing and thus its grip is lessened. Alternatively, since in most tie-bars there is no means to independently expand the collar at each end, the inner collar may still remain loose while the outer is effectively tightened in its locating hole.

An object of the present invention is to obviate or mitigate the aforesaid disadvantages.

According to the present invention a wall fixing comprises a rod having a threaded end fitted with a self-locking nut which engages with an eccentric washer such that rotation of the lock nut is prevented when the fixing is inserted into a drilled hole in a wall, and the rod bears a number of cups at said end along its length which expand to grip the interior of the trilled hole when compressed axially by means of a nut running on the threaded portion.

In a preferred form, the fixing is a cavity wall tie for remedial use, the rod having another threaded end carrying further expansibly deformable cups between two nuts.

Preferably the rod, self-locking nut, eccentric washer, expanding cups and nuts are made of stainless steel.

Preferably also the tie-bar bears near its centre a stainless steel washer to form a water drip to prevent moisture from travelling along its whole length.

According to a further feature the expanding cups may be made of nylon if the tie-bar is used in soft materials.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side view of the tie-bar according to the invention.

Fig. 2 is a side view of the self-locking nut and eccentric washer assembly according to the invention.

Fig. 3 is a side view and an end view of the selflocking nut according to the invention.

Fig. 4 is a side view and an end view of the eccentric washer according to the invention.

Fig. 5 is a side view of an expanding cup according to the invention.

Fig. 6 is a scrap cross section of expanding cups in situ on the tie-bar according to the invention.

Fig. 7 is a side view showing two modified forms of wall fixing in accordance with the invention.

A wall tie is located in holes 2 drilled into the brickwork of an inner wall 3 and an outer wall 4 separated by a cavity 5. The wall tie comprises a stainless steel rod 1 threaded at its ends. At the end of the rod 1 located in the hole 2 in the inner wall 3, is located a self-locking nut 6 which engages with an eccentric washer 7 bearing a tine 8, all these parts being of stainless steel. The selflocking nut 6 and a nut 9 are engaged with the threaded end. The eccentric washer 7 is held in place on the self-locking nut 6 by upsetting the end of the self-locking nut 6. On the portion of the rod 1 between the nut 9 and the self-locking nut 6 are located a number of stainless steel expanding cups 10. When the end of the tie is inserted into the hole 2 in the inner wall 3, the eccentric washer 7 grips the end of the hole 2 by means of its tine 8.The washer 7 being mounted eccentrically on the self-locking nut 6 prevents the self-locking nut 6 from rotating in the hole 2.

To engage the tie securely in the inner wall 3 the tie is pushed home to the back of the hole 2 in the inner wall 3 so that the self-locking nut 6 is prevented from turning by the eccentric washer 7.

The rod 1 is then screwed by means of a key (not shown) into the self-locking nut 6, drawing the nut 9 towards it. The expanding cups 10 are compressed between the nut 9 and the selflocking nut 6 and thus expand laterally to grip the inside surface of the hole 2 in the inner wall 3.

The other end of the rod 1 located in the hole 2 in the outer wall 4 is threaded to accept stainless steel nuts 11 and 12. This end of the tie is secured in place in the outer wall 4 by the same type of expanding cup 10 as is used to secure the tie in the inner wall 3. The nut 11 is screwed to the end of threading 13 on the rod 1. A number of expanding cups 10 are located along the rod 1 between nuts 11 and 12. The nut 1 2 is then screwed along the rod 1 towards the nut by means of a box spanner (not shown) 11 thus compressing the expanding cups 10, causing them to expand laterally thus gripping the inside surface of the hole 2 in the outer wall 4. By the means described in the embodiment therefore the tie is secured independently in the inner wall 3 and the outer wall 4.

The tie is provided with a stainless steel washer 14 crimped in position at its centre which prevents moisture travelling along its length to the inner wall 3.

The above embodiment is particularly suitable as a remedial wall tie, that is for insertion in an existing cavity wall where the original wall ties have failed.

Further embodiments of the invention are shown in Fig. 7 in which like parts are denoted by like reference numerals.

A shortened rod 1 5 whose end is flattened to prevent the expanding cups 10 from coming off the rod 15, or a standard bolt 1 6 with a fixed washer 1 7 may be used in a similar manner to that described in the first embodiment to secure an object 18 to a wall 19.

Claims

1. A wall fixing comprising a rod having a threaded end fitted with a self-locking nut which engages with an eccentric washer such that rotation of the lock nut is prevented when the fixing is inserted into a drilled hole in a wall, the rod bearing a number of cups at said end along its length which expand to grip the interior of the drilled hole when compressed axially by means of a nut running on the threaded portion.

2. A fixing according to claim 1 , the rod having another threaded end carrying further expansibly deformable cups between two nuts.

3. A fixing according to claim 1 or claim 2, in which the rod carries a washer forming a water drip.

4. A fixing according to any preceding claim, in which the cups are of nylon.

5. A fixing according to any of claims 1 to 3, in which the fixing is wholly of stainless steel.

6. A wall fixing substantially as herein described with reference to and as illustrated in Figs. 1 to 6 or Fig. 7 of the drawings.