AU595963B2 - Masonry anchors - Google Patents

Description

COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICAT'ION (Original) FOR OFFICE USE 595963 Class Int. Class Application Number: Lodged: poplete Specification Lodged: Accepted: Published: *Priority: "'Reilated Art: 4 f .4 4 4 44t1 I4 t N'ame of Applicant: i 4 I :I dress of Applicant: 14 t 4 Actual Inventor(s): Address for Service: RAMSET FASTENERS (AUST) PTY. LIMITED Maroondah Highway, Croydon North, 3136, in the State of Victoria, Commonwealth of Australia DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Complete specification for the invention entitled: "MASONRY ANCHORS" The following statement is a full description of this invention, including the best method of performing it known to us 1 LODGED AT SUB-OFFICE 7 DEC 1987 I M*ltoQm m _I i. (WWJttCTl- -la- 0 o. "MASONRY ANCHORS" 09 The present invention relates to masonry to anchors, and more particularly to masonry anchors for use with masonry blocks of hollow construction.

Hollow masonry blocks as currently sold in 5 Australia may be in the form of precast concrete blocks of tubular form with a single internal reinforcing web or extruded bricks having several (typically three) circular section passages arranged side by side across the width of the brick.

The attachment of anchoring devices such as bolts or studs to hollow masonry blocks is often affected by the use of a viscous adhesive material, a so-called adhesive mortar, injected into a hole drilled through the block into the cavity, the anchoring device being set into the adhesive which anchors the device when it hardens or cures. To reduce flow of the adhesive i ~iis -2away from the anchoring device, it has been proposed to insert a mesh-like or perforated sleeve into the hole to receive the adhesive. The adhesive extrudes through the sleeve to form a bulbous profile within the cavity to improve the anchorage. While this system opc,rates satisfactorily with blocks having a plurality of internal webs which provide several keying points for the adhesive, it is not entirely satisfactory for blocks of the type discussed above S 10 in which only one keying point is available, namely the internal face of the block opening onto the cavity.

t 1 I According to the invention, there is provided a sleeve for fastening an anchoring device within a hole in masonry, said sleeve being closed at its forward end and having a plurality of slots in its circumferential wall, each slot reducing in width from a rearward to a forward end such that when a V viscous adhesive material is within the sleeve and an anchoring device is pushed into the sleeve, the t adhesive material will be extruded through the slots into the hole in a rearwards direction.

Preferably, the axis of each slot is inclined to the axis of the sleeve in order to induce a rearwards flow of the adhesive in a quasi helical path to produce an annulus of adhesive material around the sleeve.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: i t I t*t f t

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t I I Figure 1 is a fragmentary sectic, showing a sleeve in accordance with a preferred embodiment in position within a hollow masonry block; and Figure 2 is an enlarged section of a detail of Figure 1.

Figure 1 is a fragmentary section through a masonry block 2 in which a hole has been drilled from its external face 4 into an internal cavity 6 to receive an anchoring device. When a hole is drilled through this type of masonry using a hammer drill, the drill usually bursts into the cavity causing a cone-like spall at the internal face opening onto the cavity. This spall is shown at 8 and impairs the provision of a good mechanical fix, due to the reduced wall thickness of the block.

In order to provice a secure fix, an anchoring sleeve 10 in accordance with the invention is inserted into the hole. The sleeve is of generally cylindrical configuration having a closed forward end 12 and an open rear end which is flanged at 14 to bear against the external face 4 of the block. The circumferential wall of the sleeve is provided with series of slots or ports 16 which permit communication between the inside and outside of the sleeve. Briefly, the sleeve 10 is filled with the adhesive mortar and the stud 18 or other anchoring device is pushed into the sleeve 10, the stud being a close, but not a tight fit within the sleeve 10. Pushing of the stud 18 into the sleeve causes mortar to be extruded from the sleeve 10 via the slots 16 to set around the sleeve 10 and firmly r. i i -4anchor the sleeve within the hole.

As will now be described, the configuration of the slots 16 is such as to provide very effective distribution of the extruded mortar around the sleeve and into the spall 8 at the internal face of the block. The slots 16 are arranged in a plurality of rows equiangularly spaced about the axis of the sleeve. Preferably, there are three or four rows of slots. Each row of slots comprises a plurality of slots spaced axially along the sleeve; as shown each '"44 row has four slots.

Each slot is of tapering shape having a wide rear end 16a and a narrow or pointed forward end 16b. The effect of this general tapering configuration is to cause the mortar to be extruded rearwardly from the slots (in other words, in a direction generally towards the external face 4 of the block) so as to fill the length of the annular space between the sleeve and the hole, and, more importantly, so that it is extruded rearwardly into the spall to form a large body 18 of supporting S".o mortar in that zone. The longitudinal axis of each slot 16 is inclined to the axis of the sleeve 10 so that the mortar is extruded in a quasi helical path whereby the mortar flows not only rearwardly but also around the sleeve 10 and the spall 8. There is thereby formed an annular body of mortar which completely surrounds the sleeve and a large Sfrusto-conical body of mortar within the spall and integral with the annular body to provide for very secure anchorage of the sleeve within the block.

~i l Preferably, the rear longitudinal edge 16c of each slot 16 is inclined so as to slope rearwardly from the inside of the sleeve to the outside whereby the slot is diffuser shaped in cross-section and which further promotes the rearwards flow.

Preferably, the respective slots in each row are of different open areas. The rearmost slot is of the greatest area with the other slots progressively reducing in area to the forward slot which has the smallest area. The purpose of this is to maximise the flow into the annular space at the rear end part of the sleeve, where there is likely to be maximum resistance to flow. The area around the spall provides relatively little flow resistance and the reduced slot area in this zone provides better control of the flow.

StT rt The embodiment has been described by way of example only and modifications are possible within r (the scope of the invention.

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Claims (8)

1. A sleeve for f astening an anchoring device within a hole in masonry, said sleeve being closed at its forward end and open at its rearward end to receive an anchoring device the sleeve having a plurality of slots in its circumferential wall, each slot reducing in width from a rearward to a forward end such that when a viscous, adhesive material is within the sleeve and an anchoring device is pushed into the sleeve through its rearward end, the too# adhesive mater'-al will be extruded through the slots o into the hole in a rearwards direction.

A sleeve according to claim 1, wherein the axis of each slot is inclined to the /axis of the sleeve in order to induce a rearwards flow of the too, adhesive in an approximately helical path to produce r t an annulus of adhesive material around the sleeve.

3. A sleeve according to claim 1 or claim 2, wherein the slots are arranged in a plurality of rows extending axially of the sleeve, with the rows being angularly displaced around the axis of t he sleeve.

4. A sleeve according to claim 3, wherein there are several such slots in each row.

A sleeve according to claim 4, wherein the open area of the respective slots in each row progressively reduces from the rear-most slot to the forward-most slot. 1

6. A sleeve according to any one of claims 1 to wherein each slot is diffuser shaped in cross-section from the internal surface of the circumferential wall to the external surface of the circumferential wall.

7. A sleeve according to claim 6, wherein the diffuser shaped cross-section is formed by inclining a rear edge of edge slot whereby to further promote S rearwards flow of the viscous material. C rt

8. A sleeve substantially as hereinbefore described with reference to the accompanying drawings. Ii F Dated this 7th day of December, 1987 tc DAVIES COLLISON t Patent Attorneys for RAMSET FASTENERS (AUST) PTY. LIMITED C tt c~ cll r' v-