GB2201214A - Expansion anchor - Google Patents

Abstract

The invention relates to a set of parts, sleeve, insert 15 and expansion member 1, for providing an expansion anchor. The sleeve is formed from two separate members 8, each of which is substantially laminated that is to say it is laminated over more than 50% of its length. The member 8 is formed from a single planar blank of metal which is rectangular with projecting lateral wings or side pieces by folding the wings back over the rectangular part about a respective line 9 defined by the junction of each wing and bar. The initial free edges 10 of the wings 11 when the folding process is completed lie substantially parallel and adjacent centrally of the rectangular part. Tangs 13 on the sleeve prevent rotation thereof, when a threaded member is passed through the insert 15 and sleeve and turned in the expansion member 1 which is also threaded. <IMAGE>

Description

EXPANSION ANCHOR The invention relates to an expansion anchor.

According to one aspect of the invention there is provided a set of parts for providing an expansion anchor, comprising an expansion member having an inclined surface portion, an insert member and a sleeve which has a laminated body and which is adapted to receive the inclined surface portion of the expansion member at one end and to abut the insert member at the other end, such that when the expansion member is moved towards the insert member, the sleeve is expanded over the inclined portion, the laminated body having outwardly projecting anti-rotational means whereby to prevent rotation of the expansion anchor in use.

According to a second aspect of the invention there is provided an expansion anchor assembled from a set of parts as hereinbefore defined.

A set of parts embodying the invention for forming an expansion anchor is hereinafter described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an expansion member; Fig. 2 is a side- view of an insert; and Fig. 3 is an elevational view of a member for forming a sleeve according to the invention.

Referring to the drawings, there is shovm part of a set of parts for assembly to provide an expansion anchor. There is a hollow internally threaded expansion member 1 which has a first generally cylindrical portion 2, an inclined surface portion 3in the form of a frusto-conical portion which tapers towards the longitudinal axis of the member, and a second generally cylindrical portion 4 which extends in a direction away from the first cylindrical portion 2, having an outer diameter identical to the smallest diameter of the frusto-conical portion 3.

The second generally cylindrical portion 4 has one or more of blind slots 5 extending in the axial direction, the or each one 5 having at its blind end a tang or detent 6 struck out of it to extend at an angle to the axis. The free end of the or each tang 6 terminates substantially in a plane which is a tangent to the outer cylindrical surface 7 of the first generally cylindrical part 2.

Stated in another way, the outer surfaces of the tangs lies on the cylindrical surface 7.

In the embodiment shown, there are four blind slots 5 and four tangs 6, spaced equiangularly round the second generally cylindrical part 4.

There is a sleeve formed from two separate members 8 which are identical and of which one is shown in Fig. 3, in which the view is towards the inner surface of the member 8. The member 8 is substantially laminated that is to say it is laminated over more than 50% of its length. The member 8 is formed from a single planar blank of metal which is rectangular with projecting lateral wings or side pieces by folding the wings back over the rectangular part about a respective,line 9 defined by the junction of each wing and bar, the initial free edges 10 of the wings 11 when the folding process is completed lying substantially parallel and adjacent centrally of the rectangular part. A nick or notch 12 of square or rectangular shape is removed from each wing 11 before folding about the lines 9. This leaves a portion 13 of the outer (in use) skin exposed.The member 8 is then curved by a suitable tool to the required configuration using a suitable forming process so the original wings form the inner skin, and the part 13 is during this process pushed outwardly to project beyond the curvature of the body. Two longitudinally extending blind slots 14 and 14' are formed in the member, one 14,- which is in a part of the material of the member 8 which is of a single thickness of metal, being shorter than the other one 14', which extends into the laminated part of the member 8. The slots 12 are longer than the slots 11 in order to accommodate movement relative to the expansion member, whereas there is no movement relative to the insert member.

The lateral edges 8' of the outer skin of the member at one end thereof taper towards the longitudinal axis from the wings 11.

Each member or sleeve 8 is also depressed to form an intermediate groove 'X' in which a means to hold two members together in this form of an encircling metal spring split clip or ring is received.

Fig. 2 shows an unthreaded insert member 15 which is tubular and formed of two cylindrical parts 16 and 17 joined by a shoulder 18.

The part 16 of larger diameter is of the same external diameter as the portion 2 of the expansion member 1 and the part 17 of smaller diameter is of the same external diameter as the portion 4 of the expansion member 1. The axial length of the part 17 substantially corresponds with that of the part of the arcuate member bearing the blind slot 14. The part 17 has two diametrically opposed blind slots 19 which terminate in outwardly (as viewed) bent tangs or detents 20 a plane through the free end of which is a tangent to the outer surface of the portion 16 (and thus to the surface 7).

The set of parts may be made from stainless steel.

The members 8 forming the sleeve being formed substantially of a laminate provide the requisite thickness and thus st-rength of the sleeve for withstanding shear and stress due to vibration, but also provide an inherent flexibility which enables the sleeve to move readily in use of the set of parts to anchor the expansion anchor in use as is hereinafter described.To assemble and use the set of parts the members 8 are mounted between the expansion member 1 and the insert member 15 with the tangs or detents 20 of the insert member 15 engaging in a respective slot 14' of the two members 8, and so that its part 17 butts against part 22 of the wings 11, and with two of the tangs or detents 6 of the expansion member 1 in respective slots 14 of the sleeve, with a tapered nose part 21 of the second cylindrical portion 4 resting on an end 23 of the wings 11, the inner thickness or wall of the laminate. The two tangs or detents 6 which are not in the slots 14 are each-received in a slot effectively formed by the diverging surface 8' of the two members 8 forming the sleeve.The metal circlip, not shown, is in the waist 'X and serves to hold the parts together firmly, but so that slight relative movement can take place. A threaded bolt is then inserted through the hollow members from the insert 15 to the expansion member 1 and screw engaged with the thread thereof to form an assembled expansion anchor. The respective tangs or detents 6, 20 and slots 8', 14 and 14' each provide locking means for securing the expansion anchor parts against relative rotation and in the assembled condition.

The expansion anchor is then inserted into a previously prepared bore of the correct diameter in material in which the expansion anchor is to be set in order to provide an anchorage or support for anything which it is desired to attach thereto. -The bolt is then rotated and this action draws the expansion body 1 towards the insert 15, so that the inclined surface 21 of the second portion 4 slides over the portion 22. As the rotation of the bolt continues the adjacent end of the members 8 forming the sleeve are forced outwards. The outer surfaces of the sleeve therefore splay out and bite into the part of the material bounding the bore to set the expansion anchor, or plug, firmly therein. During the process, and particularly during torqueing up of the bolt, the outwardly projecting diametrically opposed tangs 13 grip the wall surrounding the hole and prevent undesired rotation of the whole anchor during the setting process. The tangs 13 thus act as anti-rotational means.

Claims (12)

1. A set of parts for providing an expansion anchor, comprising an expansion member having an inclined surface portion, an insert member and a sleeve which has a laminated body and which is adapted to receive the inclined surface portion of the expansion member at one end and to abut the insert member at the other end, such that when the expansion member is moved towards the insert member, the sleeve is expanded over the inclined portion, the laminated body having outwardly projecting anti-rotational means whereby to prevent rotation of the expansion anchor in use.

2. A set of parts according to Claim 1, the anti-rotational means comprising a skin of the laminated body which is deformed outwardly.

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3. A set of parts according to Claim 2, the outer skin being deformed outwardly.

4. A set of parts according to Claim 3, the inner skin of the body being cut away adjacent the outwardly projecting anti-rotatonal means.

5. A set of parts according to Claim 4, the anti-rotational means comprising two diametrically opposed tangs.

6. A set of parts according to any preceding claim, the sleeve being formed in two separate parts divided about a plane extending through said two ends.

7. A set of parts according to Claim 6, each part having a waist intermediate its length for receiving a means to retain the parts together.

8. A set òf parts according to Claim 7, the retaining means comprising a metal spring band.

9. A set of parts according to any of Claims 2 to 8 the parts of the laminated body each comprising a piece of material folded back on itself to form the laminate.

10. A set of parts according to any preceding claim, in which the insert member comprises a pair of spaced shoulders for engaging the sleeve.

11. A set of parts for providing an expansion anchor, substantially as herein described with reference to the accompanying drawings.

12. An expansion anchor assembled from a set of parts according to any preceding claim.