GB2500963A

GB2500963A - Fastening system for a facade panel

Info

Publication number: GB2500963A
Application number: GB1300763.8A
Authority: GB
Inventors: Stefan Lind
Original assignee: NAUTH SL FASSADENTECHNIK GmbH
Current assignee: NAUTH SL FASSADENTECHNIK GmbH
Priority date: 2012-01-16
Filing date: 2013-01-15
Publication date: 2013-10-09
Anticipated expiration: 2033-01-15
Also published as: DE102012001131B4; GB201300763D0; TW201337073A; RU2013101794A; TWI577860B; RU2615951C2; GB2500963B; DE102012001131A1

Abstract

A fastening system, for a facade panel 10 which has a retaining bore with an undercut section. The system comprises a fastening anchor 30, which is provided with a thread, and a support sleeve 60. The anchor has a head 35 formed asymmetrically at a shank. The head 35 regionally protrudes in radial direction beyond the sleeve pushed onto the anchor and the support sleeve has a support section which at least regionally surrounds the head in the region in which the head does not fill out the retaining bore. The threaded portion may be an external thread or an internal thread. Also claimed is a method of fastening a facade panel by pushing the fastening anchor into the bore then pushing the anchor in a transverse direction such that the extended part of the head extends into the undercut. The sleeve is then pushed into the bore.

Description

FASTENING SYSTEM FOR A FACADE PANEL

The present invention relates to a fastening system for a facade panel.

An undercut anchor for natural-stone plates is known from the brochure fischer Zykon-Plattenanker FZP' of fischerwerke GmbH & Co. KG, Waldachtal, 2008. The undercut anchor consists of a countersunk screw, a spreader ring and a sleeve. All three parts have in the delivery state -here the spreader ring and the sleeve are pushed onto the countersunk screw -the same maximum external diameter to a first approximation.

Disposed in the natural-stone plate, in which the undercut anchor is to be installed, is a retaining bore which has an undercut in the region of its bore base. The undercut anchor, with the countersunk head of the countersunk screw foremost, is inserted almost free of force into this bore. The sleeve, which extends out of the bore and surrounds the thread of the countersunk screw, is now pressed against the bore base under spreading deformation of the spreader ring. The spreader ring is in that case spread between the head of the countersunk screw and the sleeve so that it wedges in the undercut of the retaining bore.

The present invention has the object of developing a fastening method and fastening system for facade panels in which a fastening device can be fixed in a retaining bore in the panel without radial caulking.

According to a first aspect of the invention there is provided a fastening system for a retaining bore, which is furnished with an undercut section, of a facade panel, the system comprising a fastening anchor, which is provided with an external thread, and at least one support sleeve, wherein the fastening anchor has a head asymmetrically formed at a shank, the head protrudes regionally in radial direction beyond the support sleeve pushed onto the fastening anchor and the support sleeve has a support section which at least regionally surrounds the head in the region in which it does not fill out the retaining bore.

The head is preferably formed at the shank eccentrically with respect to the centre line of the thread and has a length or diameter which is oriented transversely to the centre line and which corresponds with at least one 1.5 times the shank diameter. For preference, the geometric centre of the length of the head oriented transversely to the centre line is offset relative to the centre line by at least a quarter of the shank diameter.

In a preferred embodiment the geometric circumference of the head has an entirely or regionally cylindrical or a regionally frustoconical shape. The support sleeve is, for preference, a tubular body which has a recess at an end face, wherein the region, which is opposite the recess, represents the respective support section.

The head preferably protrudes at at least one place -transversely to the centre line -beyond the outer wall of the support sleeve by an amount which corresponds with at least a quarter of the shank diameter of the fastening anchor.

According to a second aspect of the invention there is provided a method ol fastening a fastening system to a facade panel, wherein the panel has a retaining bore with an undercut section and wherein the fastening system comprises at least one fastening anchor and a support sleeve, in which method: -production of the retaining bore with its undercut section is carried out in two stages, wherein in the first stage a cylindrical section of the retaining bore is produced by a tool and in the second stage the undercut section is produced by this or another tool from the base of the retaining bore in that the tool is, with removal of material, moved transversely to the centre line of the cylindrical section of the retaining bore, -the fastening anchor, which has a hook-shaped head, is in a first mounting step pushed into the retaining bore along the centre line so as to be pushed in a second mounting step in the direction of its hook length into the asymmetrical undercut section, -the support sleeve1 which has a recess in which the hook-shaped head fits, is pushed along the fastening anchor into the retaining bore until the recess at least regionally engages the head and the support sleeve in the mounted state protrudes by at least a few tenths of a millimetre out of the retaining bore.

For preference, the undercut section and the cylindrical section of the retaining bore have the same diameter.

According to a third aspect of the present invention there is provided a fastening system for a retaining bore, which is furnished with an undercut section, of a facade panel, the system comprising a fastening element, which is provided with an internal thread, and at least one support sleeve, wherein the fastening element has a head asymmetrically formed at its tubular body, the head protrudes regionally in radial direction beyond the support sleeve pushed onto the fastening element, and the support sleeve has a support section which at least regionally surrounds the head in the region in which it does not fill out the retaining bore.

The fastening system consisting of the fastening anchor and support sleeve enables rapid and secure mounting of a form of stud bolt at a facade panel in a corresponding bore. The fastening anchor and the support sleeve are inserted in succession into the retaining bore only by hand forca The support sleeve does not have to be knocked in. If due to production tolerances the friction between the retaining bore and the support sleeve is somewhat greater than intended the sleeve can be pressed into the retaining bore with the help of a screwdriver, a suitable tube socket or simply with the help of a short tube length.

Correct seating of fastening anchor and support sleeve can be readily recognised; if the sleeve protrudes from the rear side of the facade panel by, for example, 0.5 to 1.5 millimetres the seat is correct.

For screw-connection of the fastening anchor with a sub-structure carrying the facade panel the individual fastening anchor of stud-bolt form only has to be inserted through a corresponding bore in the sub-structure in order to then screw on a nut. Bracing of the fastening anchor is not needed for tightening this nut.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a first fastening system, mounted in a bore in a cut-away segment of a facade panel; Fig. 2 is a perspective view of the fastening system and panel segment of Fig. 1 from a different direction; Fig. 3 is a perspective view of a fastening anchor of the system, the anchor having a cylindrical head; Fig. 4 is a view similar to Fig. 3, the anchor having a conical head; Fig. 5 is a view similar to Fig. 3, the anchor having a hook-shaped head; Fig. 6 is a perspective view of a support sleeve for the fastening anchor of Fig. 3 and Fig. 4; Fig. 7 is a perspective view of a support sleeve for the fastening anchor of Fig. 5; Fig. B is a cut-away view of the facade panel segment; Fig. 9 is a cross-section of the facade panel in an undercut region of the bore; Fig. 10 is a sectional view of a fastening anchor according to Fig. 3 in front of the bore as a prelude to fastening; Fig. 11 is a view similar to Fig. 10, but showing the anchor in the bore; Fig. 12 is a view similar to Fig. 11, but showing a head of the anchor engaged in an undercut of the bore and a support sleeve in front of the anchor; Fig. 13 is a view similar to Fig. 12, but showing the support sleeve pushed onto the anchor; Fig. 14 is a view similar to Fig. 13, but showing a facade panel fixed to a sub-structure by the fastening anchor and support sleeve; Fig. 15 is a side view of a tool for forming the bore; Fig. 16 is a sectional view, to an enlarged scale, showing an assembly of sub-structure, facade panel and fastening system with the fastening anchor of Fig. 3; Fig. 17 is a view similar to Fig. 16, but with the fastening anchor of Fig. 4; Fig. 18 is a side view of a composite of fastening anchor and support sleeve of Fig. 7, the sleeve being deformed so as to be fixed in place on the anchor; Fig. 19 is an end view of the composite of Fig. 18; Fig. 20 is a longitudinal sectional view of the support sleeve of Fig. 7; Fig. 21 is a cross-section of the composite of Fig. 18, showing the anchor located in the undercut of the bore and notionally pivoted through 15 degrees; Fig. 22 is a perspective view of a modified fastening anchor with a flat; Fig. 23 is a sectional view of an assembly of sub-structure, facade panel and fastener system with sealing ring; Fig. 24 is a view similar to Fig. 23, but with a fastening anchor in the form of a tubular body; Fi9. 25 is a perspective view of a fastening anchor similar to that in Fig. 24, but with a cylindrical head; Fig. 26 is a perspective view of the fastening anchor in Fig. 24, the anchor having a conical head; and Fig. 27 is a perspective view of a fastening anchor similar to that in Fig. 24, but with a hook-shaped head.

Referring now to the drawings there is shown in Figs. 1 and 2 a cut-out segment 10 of a facade panel into which a fastening anchor 30 is inserted with mechanically positive engagement with the help of a support sleeve 60. The anchor 30 has a cylindrical head 35 which is formed at the shank 51 of the anchor 30 to be offset. The segment 10 is sectioned along the anchor 30 so that the centre lines 59 and 49 of the shank 51 and the eccentric head 35, respectively, lie in this sectional plane.

Fig. 3 shows the anchor 30 illustrated in Figs. 1 and 2. It has, for example, a length of 40 millimetres. The shank 51 has a threaded section 53 with a metric thread 54, for example M1O x 25. The front part of the shank 51, Le. the smooth shank section 52, has a cylindrical circumferential surface, the diameter of which corresponds with, for example, the nominal diameter of the thread 54. The cylindrical circumferential surface 36 of the head 35 has a diameter of, for example, 15 millimetres and a head height of, for example, millimetres. The centre line 49 of the head 35 is offset relative to the centre line 59 of the shank 51 by, for example, 2.5 millimetres.

The threaded section 53 is chamfered in the region of the rear end surface 47 of the shank 51. The chamfer 56 perpendicularly intersects the anchor plane spanned by the two centre lines 49 and 59. The chamfer 56 is in that case arranged in the half of the end surface 47 intersected by the prolongation of the centre line 49 in the inner region.

Fig. 4 illustrates a fastening anchor 31 having a head 37 with a frustoconical circumferential surface 38. The frustoconical circumferential surface 36 has a centre line coincident with the centre line 59 of the shank 51. However, this frustoconical circumferential surface 38 is cut down by a cylindrical circumferential surface 36, the diameter of which measures, for example, 15 millimetres. The centre line 49 of this cylindrical circumferential surface 36 is offset relative to the centre line 59 of the shank 51 by 2.5 millimetres.

The threaded section 53 has on the rear end surface 47 a transverse groove 57 or notch, the centre line or longitudinal direction of which lies in the anchor plane formed by the two centre lines 49 and 59.

A fastening anchor 32 is shown in Fig. 5, which has a block-shaped head 41 projecting at one side beyond the shank 51. The height of the head 41 is, for example, 5 millimetres, whilst the head width corresponds with the diameter of the smooth shank section 52. The radial side surface 36 -which, for example, is curved -of the head 41 is part of a cylindrical circumference having a diameter of, for example, 15 millimetres. The centre line 49 of this cylindrical circumferential section 36 is offset relative to the centre line 59 of the shank 51 by 2.5 millimetres.

The threaded section 53 has on the rear end surface 47 a depression 58 in the form of a conical bore, a hemispherical dent or the like. The depression 58 is cut by the centre line 49. Alternatively, the centre line of the depression 58 lies at a short spacing, for example 1 to 2 millimetres, from the centre line 49.

The chamfer 56, transverse groove 57 and depression 58 mark the orientation and/or extent of the eccentricity of the respective anchor head 35, 37, 41.

Figs. 6 and 7 show two support sleeves 60 and 70. The two support sleeves 60, 70 have an external diameter of, for example, 15 millimetres for a length similarly of, for example, millimetres. Its central bore has a diameter of 10 millimetres. This diameter is slightly greater than the diameter of the shank 51. The two support sleeves 60, 70 have material removed in the front region. The support sleeve 60 has a recess 61, in which, for example, a face miller with an outer diameter corresponding with the diameter of the cylindrical circumference 36-for example, 15 millimetres -mills along the centre line 63 to millimetres depth. The centre line 63 is offset relative to the centre line 69 of the support sleeve 60 by, for example, 2.5 millimetres. The offset is selected so that the cylindrical surface of the central bore and the inner cylindrical surface of the milled excavation 61 have a common circumferential line formed by the intersection of the cylindrical surfaces and a plane spanned by the two centre lines 69 and 63.

The recess 71 of the support sleeve 70 (cf. Fig. 7) corresponds with half a longitudinally divided tubular section of 5 millimetres length, the diametral size of which is identical with the support sleeve 70.

The depth of the respective recess 61, 71, thus the length thereof measured along the centre line 59, is smaller than or equal to the respective head height of the corresponding anchor head 35, 37, 41. According to Figs. 16 and 17 the depth corresponds with, for example, only half the head height.

Each support sleeve 60, 70 is optionally furnished with a chamfer 79 or a comparable characterising mark (cf. Figs. 12 to 14, 16 and 17). The chamfer 79 is arranged opposite the corresponding recess 61, 71 so as to facilitate positioning thereof during assembly.

Instead of the chamfer 79 the end face 66 of the support sleeve 60, 70 can have a graining, a notch or the like at a comparable location. In a given case a rectangular groove extending transversely over the end face 66 is also conceivable. By way of the rectangular groove the roughly placed support sleeve 60, 70 can then be precisely positioned by pivotation about the centre line 69 thereof.

The individual support sleeve 60, 70 can optionally have a structure 77 on its outer wall 67 (cf. Fig. 7). Arranged in the centre region of the outer wall 67 as the structure 77 are, for example, four encircling webs, which project slightly beyond the outer wall 67. The webs assist clamping of the support sleeve 70 in the retaining bore 11'. Instead of encircling webs they can also be axially parallel webs which are equidistantly distributed on the circumference of the middle region of the outer wall 67. The spacing between two adjacent webs in that case corresponds with the spacing of the encircling webs.

The resulting fastening system, consisting of the fastening anchor 30, 31, 32 and the support sleeve 60, 70, uses a special retaining bore 11 with a cylindrical section 12 and a special undercut section 21 (cf. Fig. 8). Shown there is a, for example, segment 10 of a mineral-material facade panel sectioned centrally through the retaining bore 11 The cylindrical section 12 formed on the rear side of the segment 10 perpendicularly to the surface thereof is, here, for example, 14 millimetres deep. It is ground out of the segment by, for example, a grinding tool 90.

The tool 90 is illustrated in Fig. 15. Disposed centrally at the front end on a tool shank 91 of, for example, 10 millimetres thickness is a cylindrical grinding head 92 having a diameter of 15 millimetres and a height of 5 millimetres. The grinding head 92 is wear-resistant not only at the end face, but also at its radial circumferential surface.

For producing the retaining bore 11 initially the grinding head 92 is moved into the segment 10 with a linear advance of 14 millimetres in order to then be laterally linearly moved transversely to this advance direction by, for example, 2.5 millimetres. The undercut section 21 is produced in this last processing step. The undercut section extends axially between the oval base 14 of the retaining bore 11 and the here crescent-shaped undercutflank2s(cf. Fig. 16).

The lateral direction of movement is usually the same for all retaining bores 11 of an individual facade panel. The undercut section 21 is preferably oriented so that it lies above the cylindrical section 12 when the façade panel is mounted (cf. Figs. 9to 14).

In order to produce a conical undercut section 22 for the fastening anchor variant according to Fig. 4 (of., also. Fig. 17) a grinding head having a frustoconical form is * needed. In that case, the conical frustum has, for example, the same cone angle as the head 37 of the corresponding fastening anchor 31.

For mounting of the fastening anchor 30 in the retaining bore 11 the anchor is introduced into the cylindrical section 12 (ci Fig. 10), so that the centre line 49 of the anchor head 35 is oriented to coincide with the centre line 19 of the cylindrical section 12. According to Fig. 11 the anchor 30 reaches, by the end face 45 of its head 35, the base 14 of the cylindrical section 12. The fastening anchor 30 is now displaced upwardly so that the head 35 protrudes into the undercut section 21 (cf. Fig. 12). The shank 51 of the fastening anchor 30 is centred in the cylindrical section 12 by this displacement. The centre line 59 of the shank 51 is coincidentwith the centre line 19 of the cylindrical section 12.

In order to be able to introduce the head 35, 37, 41 in the correct orientation into the undercut section 21 the threaded section 53 of the shank 51 has an appropriate marking 56, 57, 58 (cf. Figs. 3 to 5).

In a further step -if it has not taken place already -the support sleeve 60 is pushed with its recess 61 foremost on the shank 51 of the fastening anchor 30 (cf. Fig. 12) so that the support section 62 located underneath the recess 61 at least regionally surrounds the head 35 of the anchor 30 at the underside thereof (cf. Figs. 13 and 16).

In order to be able to push the support sleeve 60 in the correct orientation into the cylindrical section 12 the end face 66 of the sleeve 60 at the rear side has appropriate markings 79 (cf., inter alia, Figs. 16 and 17). The sleeve 60 pushed into the retaining bore 11 is seated therein by way of a friction couple. If as a consequence of the facade panel material a friction couple is not reliably guaranteed then use is made of a support sleeve with a structure 77 securing a clamping effect (cf. Fig. 7).

According to Figs. 1 and 2 the support section 62 extends around almost 50% of the head circumference. This also applies to the combination of the fastening anchor 31 according to Fig. 4 and the support sleeve 60 according to Fig. 6.

In both cases the combination of fastening anchor 30, 31 and support sleeve 60 can no longer be pivoted about the centre line 59, since the head 35, 37 and the support section 62 bear with shape-locking couple against the radial walls of the retaining bore 11 and the undercut section 21, 22.

If the fastening anchor 32 according to Fig. 5 and the support sleeve 70 according to Fig. 7 are used, the support section 72 of the support sleeve 70 bears against the front region of the shank 51 in which the hook-shaped head 35 is also disposed (cf., also, Figs. 18 and 19). Here, too, the fastening anchor 32 cannot rotate relative to the support sleeve 70, since the lateral flank 42 of the head 41 bears against the inner edge 73 of the support section 72 (ci Fig. 21).

Similarly, the combination of fastening anchor 32 and support sleeve 70 cannot pivot in the retaining bore 11, since the eccentric, cylindrically curved, radial outer face 36 of the head 41 (cf. Fig. 5) bears with shape-locking couple against the radial inner wall 23 of the undercut section 21. In Fig. 21 the combination of fastening anchor 32 and support sleeve is illustrated notionally pivoted relative to the retaining bore 11 through 15 degrees. As can be clearly seen, the head 41 intersects1 by its cylindrically curved outer surface 36, the contour 23 of the undercut section 21 so that an actual pivotation is impossible.

According to Figs. 1, 2, 13 and 14 the support sleeve 60 0170 is pushed to such a depth into the retaining bore 11 that it bears by the front end surface 64 thereof at least regionally against the base 14 of the retaining bore 11. As a result, there is no cavity, in which rainwater could collect, in the lower bore region closer to the ground.

After the support sleeves 60 have been placed, the facade panel 10 is suspended on a sub-structure 80 by means of the fastening anchors 30. For that purpose the threaded sections 53 of the anchors 30 are pushed into corresponding bores 61 of the sub-structure (ci Figure 14). Respective nuts 85 are subsequently screwed onto the threaded sections 5& The nuts 5 can be tightened without bracing the respective fastening anchor 30. In that case there is support, for example at the head 35 by the cylindrical circumferential surface 36 thereof, in part and in edge-free manner at the cylindrical inner wall 23 of the undercut section 21. If there is a small difference in diameter between the cylindrical circumferential surface 36 and the inner wall 23, the area pressure acting on the material of the panel is accordingly minimal.

The sub-structure 80 and the support sleeve 60 are tightened free of play with the respective heads 35 of the anchors 30 by the individual nuts 85.

During tightening of the nut 85 the material of the facade plate 10 does not experience any additional stressing apart from in the circumferential region of the head 35 (ci. Fig. 16).

Illustrated in this figure is a mounted anchor 30 which -for greater clarity -is shown seated in the retaining bore 11 with substantial play. As can be seen, the facade panel rests in radial direction of the anchor 30 only on the support sleeve 60 or the shank 51. In axial direction the head 35 does not rest by its end surface 45 on the base 14 of the retaining bore 11 and the rear end surface 46 of the head 35 does not contact the undercut flank 25 of the undercut section 21. The material of the facade plate 10 is thus not subject to any stress in axial direction of the fastening anchor 30, which could, for example, provoke fracture emanating from the undercut flank 25.

If the fastening anchor 31 according to Fig. 4 is used (cf. Fig. 17), the facade panel 10 can itself be centred relative to the anchor 31 in axial direction. In this variant the facade panel rests on the head 37 of the fastening anchor 31. Since the undercut section 22 here has a support surface in the form of a frustoconical circumference in the support region this support surface rests free of play on the head 35. Again, no axial stress in the facade panel is produced.

Illustrated in Figs. 18 to 22 is a fastening anchor 32 which has in the region of the smooth shank 52 and the head 41 a flat 55 with a depth corresponding with the thread depth of the thread 54. Fig. 22 shows the flat 55, which extends into the thread 54. The support sleeve 70 is pushed onto the anchor 32 even before installation in the facade panel. In order to mount the support sleeve 70 on the anchor 32 captively and secure against relative rotation the support sleeve 70 after being pushed onto the anchor 32 is plastically deformed in the region of the support section 72 thereof that a buckled zone is created, the inner wall 76 of which bears with play against the flat 55 of the anchor 32 (cf. Figs. 18 and 1 9) Since the flat 55 ends in the threaded section 54, the deformed support sleeve 70 cannot be withdrawn from the anchor 32. On mounting of the anchor 32 in the facade panel the support sleeve 70 is drawn back as far as possible on the fastening anchor 32 so that its end surface 65 has the maximum spacing from the head SE After pivotation or pushing of the head 41 into the undercut section 21 the support sleeve 70, guided at the flat 55 to be secure against rotation, is pushed into the cylindrical section l2of the retaining bore 11.

The fastening anchors 30 31, 32 are constructed in correspondence with the gravitational force of the facade panel to be supported, for example as Mb, M12 or also M6 or M8 anchors. The head diarñeter and thus also the inner diameter of the retaining bore 11 in that case correspond with, for example, at least 1.5 times the respective shank diameter.

The height of the respective head 36, 37,41 is equal to half the shank diameter.

The individual support sleeve 60, 70 has the external diameter of the corresponding head 35, 37, 41. The wall thickness of the support sleeve 60, 70 is a quarter of the shank diameter. The length of the support sleeve 60, 70 is matched, in accordance with requirements, to the wall thickness of the facade panel.

The individual geometric sizes of the respective fastening anchor 30, 31, 32 and the matching support sleeve 60, 70 can obviously depart from the aforesaid values as needed.

This can be required, inter alia, if the material of the facade panel is, for example, very porous. The associated material density can oblige use of a support sleeve 60 having an outer diameter greater than 1.5 times the diameter of the shank 51.

A sub-structure 80 with a facade panel fixed by way of the fastening anchors 37 is shown in Fig. 23. A resilient sealing washer 88 is arranged between the sub-structure 80, here an angle section, and the facade panel. The washer is seated, for example, on the support sleeve 60. The sealing washer 88 prevents, inter alia, penetration of moisture into the bore 11. However, particularly in the case of thin facade panel it can also transmit directly -thus not by way of the fastening anchor 37 -to the sub-structure 80 a wind loading which acts on the facade panel and presses against the facade. In this case, the sealing washer 88 can also be replaced by a plate spring.

Instead of a screw-like fastening anchor 30, 31, 32 a sleeve-shaped or bush-shaped fastening element 130, 131, 133 can also be used (cf. Figs. 24 to 27). The different fastening elements 130, 131, 133 correspond, with respect to the outer surfaces thereof, with the front parts of the fastening anchors 30, 31, 32. However, according to Fig. 24 they have a passage bore with an internal thread 154. A blind bore can obviously also used instead of the passage bore. In that case the respective end surface 45 would be formed as a closed surface.

According to Fig. 24 the clamping force, which holds the facade panel, between the support sleeve 60 bearing against the head 137 of the fastening element 131 and the angle section is produced by means of a screw 86 screwed into the thread 154. A washer 67 is optionally arranged between the head of the screw 86 and the angle section.

Claims

CLAIMS1. A fastening system for a facade panel having a retaining bore with an undercut, the system comprising a fastening member provided with a thread and with an asymmetrically arranged head, and a support sleeve mountable on the fastening member, the head protruding in a region radially outwardly of the mounted sleeve to be engageable in the undercut of the bore while leaving a part of the bore unfilled and the sleeve having a support section extending at least regionally around the head in a region thereof not filling out the bore.
2. A fastening system according to claim 1, wherein the head is formed on a shank of the fastening member and the thread is an external thread.
3. A fastening system according to claim 2, wherein the head is formed at the shank eccentrically with respect to the centre line of the thread and has a length or diameter which is oriented transversely to the axis and which is equal to at least 1.5 times the shank diameter.
4. A fastening system according to claim 3, wherein the geometric centre of the head is offset relative to the centre line of the thread by at least a quarter of the shank diameter.
5. A fastening system according to claim 3 or claim 4, wherein the head protrudes beyond the outer circumference of the mounted sleeve by an amount equal to at least a quarter of the shank diameter.
6. A fastening system according to claim 1, wherein the head is formed on a tubular body of the fastening member and the thread is an internal thread.
7. A fastening system according to any one of the preceding claims, wherein the head is at least partly cylindrical or frustoconical.
8. A fastening system according to any one of the preceding claims, wherein the wall of the sleeve is cut away in part in an end region of the sleeve to form a recess and the part of the wall left in that end region forms the support section. -15
9. A method of fastening a facade panel by a fastening system according to any one of the preceding claims, the panel having a retaining bore with an undercut section and the method comprising the steps of -pushing the fastening anchor with the head thereof foremost into the bore along the centre line thereof and then pushing the fastening anchor transversely thereto to engage the head in the undercut and -pushing the support sleeve along the anchor until the support section thereof extends at least regionally around the head in a region thereof not filling out the bore.
10. A method according to claim 9, wherein the fastening system is that according to claim B and the step of pushing the support sleeve along the anchor is carried out until the head is regionally engaged in the recess.
11. A method according to claim 9 or claim 10, wherein the axial length of the bore and that of the support sleeve are such that after the step of pushing the sleeve along the anchor the sleeve protrudes from the panel by at least some tenths of a millimetre.
12. A method according to any one of claims 9 to 11, comprising a preliminary step of forming the bore in the facade panel by producing a cylindrical section of the bore in the panel by a tool and producing the undercut of the bore at a base thereof by the same or a different tool through moving that tool transversely to the centre line of the cylindrical section to remove material laterally of the section.
13. A method according to any one of claims 9 to 12, wherein the undercut is curved with a radius of curvature the same as that of the cylindrical section.