GB1587469A

GB1587469A - Fixing plugs

Info

Publication number: GB1587469A
Application number: GB50492/77A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-12-28
Filing date: 1977-12-05
Publication date: 1981-04-01
Also published as: ATA698577A; JPS5653061B2; CS198273B2; HU175736B; BE862328A; NL169359C; DK144392B; SE7712027L; AR213223A1; GR61151B; NO144684C; NO773910L; DK457577A; DD133978A5; FR2376323A1; AU501277B2; JPS5383302A; IL53244A0; DK144392C; IT1091064B

Abstract

The dowel (4) has an internal hole (9) with longitudinal ribs (10) for screwing an attachment screw into, and has a flange (5) with a filling opening (7). The dowel (4) has a plurality of flange-like blocking elements (3), which run transversely with respect to the longitudinal axis, for fixing the dowel in the drilled hole (2). The locking elements (3) are provided with perforations (8) in the axial direction and have a profile which tapers in the form of a wedge towards the wall of the drilled hole. The remaining cavity in the drilled hole (2) is filled with a curable binding agent by means of an injection device (6) which is attached to the filling opening. The device is particularly suitable for building blocks having cavities or for porous building materials and can also be used in conjunction with wood screws. <IMAGE>

Description

(54) IMPROVEMENTS IN AND RELATING TO FIXING PLUGS (71) I, ARTUR FISCHER, a German citizen, of Weinhalde 34, D-7244 Waldachtal 3, (Tumlingen), Germany, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a fixing plug for anchoring in a drilled hole in masonry.

It is extremely difficult to fasten articles to walls that have cavities resulting from the use of cavity bricks, or to walls made of porous building materials, owing to the fact that the walls do not provide an adequate grip for fastening elements. Use may be made of extra-long plugs, which, for example in the case of hollow cavity bricks, engage with internal walls or partitions and consequently result in useful resistances to extraction owing to the distribution of the expansion pressure over several intermediate walls. Although the chance of the brick breaking up as articles are anchored in the wall and the risk of crumbling are reduced by this means, they cannot be completely ruled out. In addition, the anchorage values frequently necessary for fastening articles cannot always be achieved.

The process of embedding the fixing plug in cement has therefore become noted for porous materials in particular. For embedding in mortar a hole is prepared in the masonry, the hole being considerably larger than the external measurement of the main body of the plug. After the plug has been inserted, a hardenable bonding agent is then injected into the cavity between the wall of the drilled hole and the main body of the plug.

A known fastening element for this process comprises a metal sheath that is provided in the region of its insertion end with curved portions and for fixing in the drilled hole is provided with-an annular portion pressed onto its other end. The article is fastened using a machine screw which may be screwed into an intemal thread of the fastening element.

The present invention provides a fixing plug for anchoring in a hole in masonry, the plug having a body with an internal bore for receiving a fixing screw, means for engaging the mouth of the hole in the masonry to limit the extent to which the plug can penetrate the hole, and an opening means which is such that when the plug is placed in the hole a fixing agent can be injected through it and into the space between the body and the wall defining the masonry hole, wherein the body of the plug is provided along its length with a plurality of transversely extending annular projections, each projection being provided with an axially extending opening, and each annular projection being substantially trapezoidal in a section taken in a plane containing the longitudinal axis of the plug, the smallest longitudinal dimension of each projection being at its outer periphery.

To anchor this plug a hole is drilled in the masonry, the diameter of the hole corresponding approximately to the external diameter of the plug measured over the projections. When the plug is inserted, it is located in position in the drilled hole by these projections. The engaging means, preferably a flange, serves both to limit the depth to which the plug can be inserted into the hole and as a seal for the hole. Fixing agent is then injected through the opening means, preferably a single aperture in the flange, into the space or cavity formed between the outer wall of the body of the plug and the wall of the masonry hole.

Because the projections are provided with axially extending openings the drilled hole is completely filled. To facilitate filling of the masonry hole when using the plug according to the invention in masonry having no cavities, it is an advantage to provide ventilation opening(s) in the flange.

Because the projections taper towards the wall of the drilled hole and have a wedge shaped profile, segments of the core of fixing agent are formed, these segments being joined together by the axially extending openings and widening outwards, in the shape of a wedge, towards the wall of the drilled hole.

These segments ensure high resistances to extraction owing to the intimate join with the wall of the drilled hole. Because the projections are wider at the main body of the plug the shearing strength of the projections is additionally increased and the resulting rigidity prevents the plug from slipping when it is subjected to extraction stress.

Additionally, the wedge-shape of the projections changes the extraction stress which is effective in the axial direction of the plug into a force which acts at right angles to the faces of the projections and is thus directed towards the wall of the drilled hole. The friction of the core of fixing agent against the wall of the drilled hole is thereby additionally reinforced by an expansion force pressing the core of fixing agent against the wall of the drilled hole when the plug is subjected to an extraction stress, so that very high resistances to extraction are obtained.

In particular cases for example when a fastening is required in edge region, it may be necessary to use a plug having a relatively small outer diameter. The gap remaining between the wall of the drilled hole and the outer face of the main body of the plug is, under certain circumstances, of insufficient size for an aperture in the flange to be placed in communication with it. Further, the width of that aperture, owing to the viscosity of the fixing agent to be injected, should not be below a certain size.

In this case, it is of advantage, therefore, if the flange is annular and has a radially outwardly extending lug-like projection provided with the opening means (preferably a single aperture).

By this design it is now acceptable for the injection aperture not to be aligned with the gap formed between the main body of the plug and the wall of the masonry hole, and to be thus partially, or in extreme cases even completely, masked by the masonry and sealed off. The external dimensions of the plug measured over the projections can now therefore be matched very closely to the outer diameter of the main body of the plug, so that the drilled hole for accommodating the plug is only slightly larger than the diameter of the main body of the plug. The plug according to the invention can therefore also be anchored in edge regions and for example, in the end faces of thin-walled parts. Care should be taken that the plug is always inserted into the drilled hole such that the radial extension of the flange comes to lie against a region of the masonry which is relatively thick.

Before the fixing agent is introduced, any masonry behind the injection aperture is broken away. Since masonry material is usually porous and soft, this can be effected in a simple manner by penetration with a screwdriver, a nail or the like. Thereafter, the drilled hole is filled with fixing agent through the passage that has been made. There is consequently an opening available for injection of the fixing agent which can be considerably larger than the width of the gap between the wall of the drilled hole and the outer face of the main body of the plug.

Advantageously, the opening means comprises one or more apertures formed in the body of the plug adjacent to the engaging means and communicating with that portion of the plug bore adjacent to the engaging means, the remaining portion of the plug bore being sealed off from the opening means by a frangible membrane.

The use of part of the internal bore of the plug for injecting the fixing agent enables plugs of smaller sizes to be anchored as well, the preferably injection-moulded plastics, membrane keeping the remaining and major part of the internal bore of the plug free of fixing agent so that a fastening screw can be screwed in subsequently. To facilitate the production of the plug by an injection moulding process, the internal bore has to be open at its insertion end. However, the fixing agent is prevented from penetrating into the internal bore at the insertion end of the plug by a cushion of air which builds up in the plug bore. After the fixing agent has hardened the membrane is punctured (for example by a screwdriver or a nail) and a screw is inserted into the plug bore, the tip of the screw serving to crush and dislodge any fixing agent which does penetrate.

To prevent any fixing agent at all penetrating into the internal bore at the insertion end of the plug, a cap may be provided on that end of the plug to cover the internal bore.

When the plug has very small dimensions, and the injection opening means is correspondingly smaller, it is possible that the nozzle tip of a fixing agent injection device can no longer be placed effectively against the opening means.

Advantageously, therefore, an element is provided which is removably engageable in the plug bore and which has an inlet opening, preferably funnel-shaped, for registering with the injection aperture in the flange, when the element is engaged in the internal bore of the plug.

The element acts as a mouth-piece enabling the injection device to be effectively positioned against the injection aperture without any risk of it slipping off. The mouth-piece also substantially prevents the fixing agent from being squeezed laterally during the injection process.

Advantageously, to facilitate location of the mouth-piece element against the injection aperture, the wall plug and that element are provided with location means which means engage when the inlet in that element- is in alignment with the said aperture.

This feature ensures that the mouth-piece element is aligned with the injection aperture in the flange; the location means may comprise a notch or recess provided on the wall plug of the said element and a projection provided on the said element or the wall plug respectively.

Problems can occur when the drilled hole is being filled with fixing agent if any substructures, plasterboard panels or the like have been mounted against the masonry. There may be gaps between these panels and the masonry, especially when the surfaces of the masonry are uneven, into which the fixing agent injected into the drilled hole may emerge. Apart from the loss of fixing agent, this may also lead to the outer face of the wall becoming dirty.

To prevent this, it is of advantage if a sheath is provided for the wall plug, the sheath being mountable over the wall plug so that it resides behind the engaging means and extends over a portion of the length of the wall plug.

The sheath has to be a little longer than the thickness of the structure placed against the masonry so that a portion of the sheath still engages in the drilled hole. By this means a seal is provided for the drilled hole which prevents the fixing agent emerging into the gaps present between the masonry and the structure. The tubular sheath guides the fixing agent, which passes inside it to the part of the drilled hole located in the masonry. By placing the sheath against the wall of the drilled hole it is impossible for the fixing agent to flow back over the outer face of the sheath. The axial fixing of the sheath can be effected by clamping it firmly between the projections and the wall of the masonry hole.

The present invention also provides a fixing plug for anchoring in a hole drilled in masonry by filling up the drilled hole with a fixing agent, wherein the plug has an internal bore for screwing in a fastening screw, and a flange that is provided with an injection opening for passage of fixing agent and seals off the drilled hole, wherein the plug is provided with several flange-like retaining members which extend transversely to the longitudinal axis and locate the plug in the drilled hole, the retaining members having apertures in the axial direction and a wedge-shaped profile tapering towards the wall of the drilled hole.

Various wall plugs, each constructed in accordance with the invention, will now be described, by way. of example only, with reference to the accompanying drawings, in which: Fig. 1 is a longitudinal section of a wall plug which has been fixed in place in a bore in masonry.

Fig. 2 is a cross-section of the wall plug along the line I I in Fig. 1.

Fig. 3 is a longitudinal section of another wall plug which has been fixed in position in a hole in masonry.

Fig. 4 is a cross-section of the wall plug shown in 1Fig. 3 along the line Il-Il in Fig. 3.

Fig. 5 is a longitudinal section of a further wall plug which has been fixed in place in a hole in masonry.

Fig. 6 is a longitudinal section of a still further wall plug which has been fixed in place in a hole in masonry, and Fig. 7 shows a wall plug similar to that shown in Fig. 6 with a sheath pulled over part of the wall plug.

Referring to the accompanying drawings, each of the wall plugs shown in Figs. 1 to 7 has been anchored or fixed in position in a hole 2 which has been drilled or otherwise formed in masonry (which may, for example, be a wall) i. Each wall plug comprises a longitudinally extending body 4 which has a longitudinal bore 9 for receiving a fixing screw, for example a wood screw, the end of the wall plug remote from its insertion end being provided with a flange 5 which limits the depth to which the plug can be inserted into the hole 2 in masonry and which also serves to seal off the mouth of the hole 2.

Along the length of the wall plug body 4 are several transversely extending annular ;flange-like retaining members 3. Each retaining member 3 has at least one axially extending aperture in the form of a resess or notch 8 formed in its outer periphery. Further, each retaining member 3 has, in longitudinal section, a substantially trapezoidal form, the smallest longitudinal dimension of each retaining member being at the outer periphery of that member. Put another way, each member has a wedge-shaped profile which tapers towards the wall defining the hole 2 in the masonry.

One or more small bore ventilating aperture(s) 13 is provided in the flange 5 of each plug-except that shown in Fig. 1 but this construction too could be provided with such an aperture.

The internal bore of each wall plug 9 is, as mentioned above, for receiving a wood screw and to facilitate reception of the screw within the bore the latter is provided with longitudinally extending ribs 10 (see especially Fig. 2 and Fig. 4).

In each case also -- except the wall plug shown in Fig. 5 -- the flange 5 is provided with an injection opening 7 which is arranged to open out into the gap 2 between the body 4 of the plug and the wall of the hole 2. A nozzle 6 of an injection device can be inserted into the injection opening 7 to inject a fixing agent into the space formed between the body 4 of the wall plug and the wall defining the hole or bore 2 in the masonry. In the case of the wall plug shown in Fig. 5, two diametrically opposite apertures 7 are provided in the body or wall of the wall plug immediately behind the flange 5. In this case the nozzle 6 is inserted into the mouth of the wall plug as shown in Fig. 5, and the fixing agent injected into the space 2 via the diametrically opposed apertures 7.

The fixing agent which is injected into the space surrounding the wall plug may be any suitable cementing or bonding material which may, for example, be a mortar, or any suitable hardenable material, for example, plastics material such as a foamable plastics material (which may, for example, by polyurethane).

That is to say, any material may be injected which will serve permanently to fix or secure in position the wall plug within the aperture or hole in the masonry.

To carry out the anchoring process the hole 2 is drilled in the masonry 1, the diameter of the hole - at least in the region of the mouth of the hole 2 -- corresponding to the outer diameter of the wall plug body measured over the retaining members 3. In the case of the plug shown in Fig. 1 the diameter of the hole is constant but in the case of the plugs of Figs. 3 to 7 it will be seen that the diameter of the hole is approximately the same as the major diameter of the wall plug (that is to say the diameter measured over the retaining members) adjacent to the mouth of the hole 2 but the diameter of the base of the hole is increased by undercutting or under-reaming.

When the hole 2 has been drilled out the wall plug 4 is inserted into the hole until the flange 5 abuts the mouth of the hole. In this way the flange 5 acts not only to limit the depth to which the wall plug can be inserted in the hole, but it also serves to seal off the mouth of the hole.

In the case of all the wall plugs except that shown in Fig. 5, the injection nozzle 6 is then used to inject a fixing agent through the injection orifice 7 and into the space surrounding the wall plug. In the case of the Fig. 5 arrangement as mentioned above, the nozzle is inserted into the mouth of the central bore of the wall plug and the fixing agent injected through the apertures 7. The ventilating aperture(s) 13 serves to ventilate the hole 2 as the fixing agent is injected.

The flange-like retaining members 3 serve to increase the anchoring effect of each of the wall plugs 4 in the masonry, and because of the trapezoidal shape of the retaining members in longitudinal section, especially good anchoring conditions are achieved. These retaining members have apertures 8 extending in the axial direction which ensure that when the fixing agent is injected it can pass along the length of the plug and facilitate total filling of the hole 2 surrounding the plug.

In the case of the wall plug shown in Fig.

1 its dimensions are such that the gap between the body of the wall plug 4 and the wall of the bore 2 in the masonry is sufficiently large to allow an injection opening 7 to be provided in a circular flange 5 as shown in Fig. 2. However, in the case of the arrangement shown in Fig. 3, for example, because of the relatively small radial extent of the retaining members 3 of the wall plug, the gap between the body 4 of the wall plug and the wall of the cavity 2 is too small to have the injection opening 7 provided in a corresponding -- but smaller circular flange 5. Thus, the injection opening must - usually - have a certain minimum diameter (due to the viscosity of the fixing agent). This problem is overcome by providing the circular flange 5 with a lug-like extension 11 which extension is provided with the open ing 7.When this wall plug is used that part of the masonry which has not been broken away and which will lie behind the injection opening 7 is punctured with a sharp tool to produce a passage 12 leading to the bore 2 accommodating the wall plug. Thus again the injection opening 7 can be used to inject material through the passage 12 and into the cavity 2.

In the case of the wall plug shown in Fig.

5, the bore 9 is closed by a membrane 14 which, in the case of an injection moulded plug, can be moulded integrally with the body of the plug. In this way, fixing agent which is injected through the mouth of the bore (as shown in Fig. 5) and out through the apertures 7 is prevented from penetrating into the internal bore 9 of the wall plug. Penetration of the fixing agent into the bore from the insertion end of the plug .- at least at low injection pressures -- is prevented by a cushion of air which builds up inside the internal bore.

However, at higher injection pressures it is advisable to close off the internal bore at both ends by providing a closure cap 15 at the insertion end of the wall plug.

After the fixing agent has hardened the injection moulded membrane 14 is punctured, for example, by a screw driver or nail. An article can then be fastened to the wall using a wood screw which, as it is screwed into the internal bore 9 of the wall plug, dislodges and/or crushes any fixing agent present at the mouth of the bore 9.

In order to be able properly to position and hold in place the injection device or nozzle 6 in an injection opening 7 when the wall plug has relatively small dimensions as shown in Fig. 6, a mouth-piece 16 can be provided. The mouth-piece 16 has a funnel-shaped opening 17 which is matched to the nozzle tip of the injection device 6. The mouth-piece 16 can be correctly positioned against the injection opening 7 by means of a member 18 in the form of a peg which slidably engages in the internal bore 9 of the wall plug. The closure member 18 is connected integrally to the mouth-piece 16. To assist proper location of the funnel-shaped opening 17 with the injection opening 7, the closure peg 18 is provided with a projection 20 which, when it engages in a complementary recess 19 in the bore of the wall plug, ensures that the funnel and opening are in alignment.

The mouth-piece 16 also prevents the fixing agent from being squeezed outwards between the nozzle 6 and the opening 7. Further, the mouth-piece allows the diameter of the opening 7 to be reduced to a minimum value consistent with allowing satisfactory flow of fixing agent through it.

The wall plug arrangement shown in Fig.

7 is much the same as that shown in Fig 6, except that a sheath 21 has been pushed over the insertion end of the wall plug until it is adjacent to the flange 5. This arrangement is particularly useful where one wishes to support a sub-structure 22 (for example a plaster board panel or the like) against the wall formed by the masonry 1. In this case a hole (the diameter of the hole corresponding to the diameter of the sheath 21) is drilled through the structure 22 as well as the mortar 1 as shown in Fig. 7. The wall plug, together with the sheath 21, is then inserted until the flange 5 engages and abuts the outer face of the structure 22. As will be seen in Fig. 7 because the sheath 21 is a little longer than the thickness of the structure 22 it extends axially beyond the gap 23 formed between the structure 22 and the masonry 1.Accordingly, when a fixing agent is injected via the mouth-piece 16 and opening 7 into the cavity 2 the fixing agent does not leak out into the gap 23.

The sheath 21 is axially fixed in position by being clamped between the wall of the hole 2 in the masonry and the retaining members 3 of the wall plug.

The sheath 21 shown in Fig. 7 may be used with all the other illustrated wall-plugs.

WHAT I CLAIM IS: 1. A fixing plug for anchoring in a hole in masonry, the plug having a body with an internal bore for receiving a fixing screw, means for engaging the mouth of the hole in the masonry to limit the extent to which the plug can penetrate the hole, and an opening means which is such that when the plug is placed in the hole a fixing agent can be injected through it and into the space between the body and the wall defining the masonry hole, wherein the body of the plug is provided along its length with a plurality of transversely extending annular projections, each projection being provided with an axially extending opening, and each annular projection being substantially trapezoidal in a section taken in a plane containing the longitudinal axis of the plug, the smallest longitudinal dimension of each retaining projection being at its outer periphery.

2. A plug as claimed in claim 1, in which the engaging means is a flange.

3. A plug as claimed in claim l or claim 2, in which the opening means is a single aperture provided in the engaging means.

4. A plug as claimed in claim 2 or claim 3 when appendant to claim 2, in which the flange is annular and has a radially outwardly extending lug-like projection which is provided with the said opening means.

5. A plug as claimed in claim 1 or claim 2, in which the opening means comprises one or more apertures formed in the body of the plug adjacent to the engaging means and communicating with that portion of the plug bore adjacent to the engaging means, the remaining portion of the plug bore being sealed off from the opening means by a frangible membrane.

6. A plug as claimed in claim 5, in which a cap is provided on the insertion end of the wall plug to cover the internal bore of the plug.

7. A plug as claimed in claim 5 or claim 6, in which the opening means comprises two apertures.

8. A plug as claimed in claim 7, in which the two apertures are substantially diametrically opposite.

9. A plug as claimed in claim 3, in which an element is provided which is removably engageable in the plug bore and which has an inlet opening for registering with the opening means when the element is engaged in the bore.

10. A plug as claimed in claim 9, in which the inlet opening is funnel-shaped.

11. A plug as claimed in claim 9 or claim 10, in which the wall plug and the said element are provided with location means, which means engage when the inlet in the said element is in alignment with the opening means.

12. A plug as claimed in claim 11, in which the location means comprises a notch or recess provided on the wall plug of the said element and a projection provided on the said element or the wall plug respectively.

13. A plug as claimed in any one of claims 1 to 12, in which a sheath is provided for the wall plug, the sheath being mountable over the wall plug so that it resides behind the engaging means and extends over a portion of the length of the wall plug.

14. A plug as claimed in any one of claims 1 to 13, in which each of the axially extending openings in the annular projections is in the form of a notch or recess provided in the outer periphery of the annular member.

15. A fixing plug for anchoring in a hole drilled in masonry by filling up the drilled hole

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

be correctly positioned against the injection opening 7 by means of a member 18 in the form of a peg which slidably engages in the internal bore 9 of the wall plug. The closure member 18 is connected integrally to the mouth-piece 16. To assist proper location of the funnel-shaped opening 17 with the injection opening 7, the closure peg 18 is provided with a projection 20 which, when it engages in a complementary recess 19 in the bore of the wall plug, ensures that the funnel and opening are in alignment.

The mouth-piece 16 also prevents the fixing agent from being squeezed outwards between the nozzle 6 and the opening 7. Further, the mouth-piece allows the diameter of the opening 7 to be reduced to a minimum value consistent with allowing satisfactory flow of fixing agent through it.

The wall plug arrangement shown in Fig.

7 is much the same as that shown in Fig 6, except that a sheath 21 has been pushed over the insertion end of the wall plug until it is adjacent to the flange 5. This arrangement is particularly useful where one wishes to support a sub-structure 22 (for example a plaster board panel or the like) against the wall formed by the masonry 1. In this case a hole (the diameter of the hole corresponding to the diameter of the sheath 21) is drilled through the structure 22 as well as the mortar 1 as shown in Fig. 7. The wall plug, together with the sheath 21, is then inserted until the flange 5 engages and abuts the outer face of the structure 22. As will be seen in Fig. 7 because the sheath 21 is a little longer than the thickness of the structure 22 it extends axially beyond the gap 23 formed between the structure 22 and the masonry 1.Accordingly, when a fixing agent is injected via the mouth-piece

16 and opening 7 into the cavity 2 the fixing agent does not leak out into the gap 23.

The sheath 21 is axially fixed in position by being clamped between the wall of the hole 2 in the masonry and the retaining members 3 of the wall plug.

The sheath 21 shown in Fig. 7 may be used with all the other illustrated wall-plugs.

WHAT I CLAIM IS: 1. A fixing plug for anchoring in a hole in masonry, the plug having a body with an internal bore for receiving a fixing screw, means for engaging the mouth of the hole in the masonry to limit the extent to which the plug can penetrate the hole, and an opening means which is such that when the plug is placed in the hole a fixing agent can be injected through it and into the space between the body and the wall defining the masonry hole, wherein the body of the plug is provided along its length with a plurality of transversely extending annular projections, each projection being provided with an axially extending opening, and each annular projection being substantially trapezoidal in a section taken in a plane containing the longitudinal axis of the plug, the smallest longitudinal dimension of each retaining projection being at its outer periphery.

2. A plug as claimed in claim 1, in which the engaging means is a flange.

3. A plug as claimed in claim l or claim 2, in which the opening means is a single aperture provided in the engaging means.

4. A plug as claimed in claim 2 or claim 3 when appendant to claim 2, in which the flange is annular and has a radially outwardly extending lug-like projection which is provided with the said opening means.

5. A plug as claimed in claim 1 or claim 2, in which the opening means comprises one or more apertures formed in the body of the plug adjacent to the engaging means and communicating with that portion of the plug bore adjacent to the engaging means, the remaining portion of the plug bore being sealed off from the opening means by a frangible membrane.

6. A plug as claimed in claim 5, in which a cap is provided on the insertion end of the wall plug to cover the internal bore of the plug.

7. A plug as claimed in claim 5 or claim 6, in which the opening means comprises two apertures.

8. A plug as claimed in claim 7, in which the two apertures are substantially diametrically opposite.

9. A plug as claimed in claim 3, in which an element is provided which is removably engageable in the plug bore and which has an inlet opening for registering with the opening means when the element is engaged in the bore.

10. A plug as claimed in claim 9, in which the inlet opening is funnel-shaped.

11. A plug as claimed in claim 9 or claim 10, in which the wall plug and the said element are provided with location means, which means engage when the inlet in the said element is in alignment with the opening means.

12. A plug as claimed in claim 11, in which the location means comprises a notch or recess provided on the wall plug of the said element and a projection provided on the said element or the wall plug respectively.

13. A plug as claimed in any one of claims 1 to 12, in which a sheath is provided for the wall plug, the sheath being mountable over the wall plug so that it resides behind the engaging means and extends over a portion of the length of the wall plug.

14. A plug as claimed in any one of claims 1 to 13, in which each of the axially extending openings in the annular projections is in the form of a notch or recess provided in the outer periphery of the annular member.

15. A fixing plug for anchoring in a hole drilled in masonry by filling up the drilled hole

with a fixing agent, wherein the plug has an internal bore for screwing in a fastening screw, and a flange that is provided with an injection opening for passage of fixing agent and seals off the drilled hole, wherein the plug is provided with several flange-like retaining members which extend transversely to the longitudinal axis and locate the plug in the drilled hole, the retaining members having apertures in the axial direction and a wedge-shaped profile tapering towards the wall of the drilled hole.

16. A wall plug substantially as hereinbefore described, with reference to and as illustrated by Figs. 1 and 2, IFigs. 3 and 4, Fig. 5, Fig. 6 or Fig. 7 of the accompanying drawings.