ATTACHMENT PLUG

Abstract: The invention relates to an attachment plug for attaching linings, bolts, screws, pins etc. to a wall. The attachment plug comprises a sheet (2) of spring steel, which is bent to form a substantially cylindrical sleeve, said sleeve being provided with lugs (3-6) spaced apart along said sleeve and punched from the metal sheet and bent outwardly at a certain angle. The lugs punched in the sleeve comprise at least two different lengths of lugs (3, 5; 4, 6), said lugs being disposed in the longitudinal direction of the sleeve, one after the other, and comprising short lugs (3; 4) and long lugs (5; 6) in an alternating sequence. Two sets of lugs (3, 5) are bent in a direction outwardly from said sleeve and two sets of lugs (4, 6) are bent in a direction towards the inner portion of said sleeve, each set of lugs comprising at least two different lengths of lugs (3, 5 respectively 4, 6). The ends of the lugs bent outwardly (3, 5) are directed towards the inner end of the sleeve and the ends of the lugs (4, 6) bent inwardly are directed towards the outer end of the sleeve.

Description: ATTACHMENT PLUG The present invention relates to an attachment plug for attaching linings, screws, pins etc to a wall, said at- tachment plug comprising a substantially cylindrical sleeve formed by bending a metal sheet, said cylindrical sleeve comprising lugs punched in the metal sheet and bent out¬ wardly, said lugs being spaced apart in the longitudinal direction of said sleeve. The attachment plug according to the invention is particularly well suited for use for mounting insulation on a house wall, but is also suited for use as nail plug, plug for hollow concrete stone, wall face plug and as conven¬ tional expansion plug. Attachment plugs of the kind mentioned initially are previously known. Available on the market are thus attach¬ ment plugs of plastic material or metal which on the out¬ side are provided with outwardly projecting lugs or tongues which yield when the plug is inserted into a bore hole, but blocks against removal of the plug by traction. Sleeve-like attachment elements made of thin steel sheet having lugs or tongues punched in the sleeve-like shell thereof and serv¬ ing as blocking elements, are also previously known, said attachment element comprising two series lugs or tongues bent outwardly. One series of tongues is bent in a direc¬ tion outwardly from said sleeve and in a direction back¬ wards in order to block against removal of the attachment element from the hole in which it is inserted, and the other series of tongues is bent in a direction inwardly to- wards the inner portion of the sleeve and having their free ends directed toward the inner end of the sleeve for en¬ gagement with a screw etc which is introduced into the sleeve. Previously known attachment plugs of the kind men- tioned above are available on the market in a great number of embodiments intended for different kinds of wall ma¬ terial and having each attachment plug within the different types of embodiments intended for a certain diameter of the screw, the pin etc which shall be attached to the _wall by means of the attachment plug. The lugs or tongues pro¬ jecting outwardly from the attachment plugs have a uniform length, which means that plugs intended for insertion in walls of a hard material are not suitable for insertion in walls of a soft material, e.g. light weight concrete, since when inserting the attachment plug into a soft material, the rigid lugs will tend to cut a groove into the wall ma¬ terial and thus providing very small blocking action against removal of the attachment plug from the wall. In those cases where the attachment plug includes inwardly di- rected projections, lugs or tongues, the attachment plug can be used only for wood screws having a diameter within a very narrow diameter range. The present invention relates to an attachment plug of the kind mentioned initially, which is also suitable for fitting in different kinds of wall material, such as brick, concrete, light weight concrete, hollow concrete, stone etc, and which is particularly well suited for use for mounting insulation or other linings on walls, and which for one and the same hole dimension allows for the use of screws, bolts, pins etc of different diameters. The objects mentioned above are obtained by a con¬ struction in accordance with the appended claims. The invention will be described below in connection with an exemple of an embodiment with reference to the en- closed drawing, on which fig 1 shows an enlarged side view of an attachement plug according to the invention, said plug being intended to be used for attaching e.g. an insulating layer on the inside of a wall. Fig 2 is a section taken as shown by arrows A-A and C-C in fig 1. Fig 3 is a section taken as shown by arrows B-B in fig Fig 4 is a section taken as shown by arrows D-D in fig * Fig 5 is a section taken as shown by arrows E-E in fig Fig 6 is a section taken as shown by arrows F-F in fig Fig 7 is an end view of the attachment plug according to fig 1 as shown by arrows G-G. Fig 8 is a development of the attachment plug formed from a thin rectangular spring steel and having tongues of lugs punched in the spring steel. Fig 9 schematically illustrates the development of a variant of the attachment plug according to the invention to be used as a conventional plug. The attachment plug 1 illustrated in enlarged scale in figures 1-8 is particularly intended for use for attach¬ ing a lining, e.g. a layer of insulating material on a wall. The attachment plug thus includes an inner portion to be introduced into a bore hole in the wall with the dimen¬ sions of tghe bore hole adapted to the dimensions of the plug, and an outer portion which, after inserting the plug in said hole, protrudes from the wall a distance which sub¬ stantially corresponds to the thickness of the lining, e.g. the insulating layer which shall be attached to the wall. The attachment plug 1 is made of a rectangular thin sheet 2 of spring steel, preferably stainless acid proof steel. In the front portion of the sheet 2 i.e. the portion which after bending the sheet 2 into sleeve form, constitutes the inner part of the attachment plug for insertion into the wall, a number of lugs or tongues 3, 5 are punched, said lugs or tongues to be bent outwardly at an angle from the sheet which is bent into sleeve form. The free ends of said lugs are further bent outwardly. The punching has been made so that after bending outwardly the free ends of said lugs are directed away from the inner end of the attachment plug 1. The punched lugs comprise two series of lugs 3 and 5 having different lengths, all of them having a convexly curved terminal edge. As seen in fig 2 the lugs of the il¬ lustrated embodiment are punched one after the other to form raws. The uppermost raw starts with a short lug 3, followed by a long lug 5 and then a short lug 3. The adja¬ cent raw starts with a long lug 5, followed by a short lug 3 and then a long lug 5. The pattern is repeated around the sleeve-formed inner portion of the attachment plug. A number of lugs or tongues 4 and 6 are also punched in the rear portion of sheet 2 of spring steel, i.e. in the portion, which after bending of the sheet into sleeve form and inserting the attachment plug into a hole in the wall protrudes outside the wall, said lugs or tongues to be bent at an angle inwardly into the sheet bent into sleeve form. The punching of said lugs 4, 6 is such that the free ends of the inwardly bent lugs, which have a concave curved edge, are directed away from the outer end of the attach¬ ment plug, i.e. inwardly towards the inner end of the sleeve-formed attachment plug. The free ends of said lugs are further bent inwardly. The lugs punched in this portion of the attachment plug also include two series of lugs 4, 6 having different lengths, which, like the lugs in the outer portion of the attachment plug, are punched one after the other to form raws. The uppermost raw thus comprises a short lug 4, followed by two long lugs 6, as seen from the outer end of the attachment. The adjacent raw starts with a short lug 4, followed by another short lug 4 and then a long lug 6. This pattern is repeated in adjacent raws around the periphery of the attachment plug. The number of raws having lugs 3, 5, bent outwardly in the inner end portion of the attachment plug 1 may be subject to variations, as well as the number of lugs in each raw. The presence of at least two series of lugs having different lengths and alternating short lugs and long lugs, with result in that the attachment plug may be used in hard materials as well as in porous materials. In hard materials said short lugs provide a more firm grip due to the stiffness than the long lugs which are more re- silient. In porous materials, e.g. light weight concrete, the short lugs tend to cut a groove for the following long lugs, which thus will obtain a greater deflection angle outwardly, resulting in an improved ability of supporting forces acting upon the attachment plug in a direction out- wardly. The number of raws of lugs which are bent inwardly as well as the number of lugs in each raw may also be subject to variations. The fact that there are at least two series of lugs of different lengths which are bent inwardly is ad- vantageous in that an attachment plug according to the in¬ vention of a certain dimension can be used for several dif¬ ferent dimensions of screws or pins. The inwardly deflected lugs are also advantageous in that the screws do not need to be screwed into the attachment plug but may be intro- duced into the attachment plug by tapping or pushing action and then be tightened by means of a screw driver. The in¬ wardly deflected lugs also allow for the use of screws or bolts having different types of threads, i.e. screws with conical threading as well as screws with cylindrical threading. The lugs 4 situated at the right end serve for centering and stabilizing a screw which is introduced into the sleeve. All lugs 4 and 6, having different lengths, are deflected inwardly such a distance that the free ends of said lugs terminate at the same distance from the centre axis of the attachment plug to form a centre opening having the same diameter. The deflecting angles of the lugs 4 and 6 respectively are thus different. As appears from fig 8 a number of tapering lugs 7 are punched in the front short side of the rectangular sheet 2, said lugs to be bent at an angle inwardly to form a point or a rounded point 8 on the inner end of the attachment plug, e.g. as shown in fig 1, when the sheet 2 is bent to form a sleeve. As further appears from fig 8 the opposite short side of the rectangular plate 2 is provided with a collar 9 at the extreme end of the attachment plug, said collar being directed outwardly at right angle. When at¬ taching a lining, e.g. an insulating layer on a wall, the insulating layer is passed over the attachment plugs pro¬ truding from the wall and is then secured in position by presssing insulation retaining means, e.g. a slotted bracket over said collar 9. The attachment plug described with reference to fig¬ ures 1-8 is, as mentioned, intended for use for attaching a lining on a wall and does thus protrude outside the wall and comprises lugs which are bent inwardly only in the outer portion of the attachment plug. However, the inven¬ tion also comprises embodiments intended for use as a con¬ ventional plug which is completely introduced into the bore holes in the wall and which in addition to lugs which are bent outwardly also include lugs bent inwardly. A pattern for punching lugs which are bent outwardly as well as lugs which are bent inwardly in such an embodiment of the at¬ tachment plug according to the invention, is schematically illustrated in fig 9. In this figure the lugs extending outwardly have been indicated with a horizontal, parallel sectioning and the lugs extending inwardly have been indi¬ cated with a parallel sloping sectioning. As appears from fig 9 long lugs 5 directed outwardly and short lugs 3 di¬ rected outwardly are punched in the sheet 10 in an alter- nating sequence and in adjacent raws, and long lugs 6 di- rec ed inwardly and short lugs 4 directed inwardly in al¬ ternating sequence. This embodiment of the attachment plug may be provided with a point or a rounded point 8 and with a collar 9 in a corresponding way as described with re- ference to figures 1-8. The transversal cross section of the lugs 3, 4, 5, 6 may have a plane, rectangular form. In that case the lugs will be relatively resilient, which may be preferred for attachment plugs intended for attachment in porous ma- terials, e.g. light weight concrete. If a greater stiffness of the lugs is desired, said lugs may be punched during ma¬ nufacture so that a transversally curved cross section hav¬ ing concave or convex curvature is obtained. Such an em¬ bodiment is preferred for attachment plugs intended for at- tachment in hard materials, e.g. brick, concrete etc. Instead of extending substantially along a straight line in the direction sloping outwardly or inwardly re¬ spectively, the lugs 3-6 may be bent with a curvature out¬ wardly or inwardly respectively as indicated by dash-and- dot lines at the lug 5 of fig 1. The invention is not limited to the embodiments de¬ scribed above, but may be subject to variations within the scope of the appended claims.

Claims: CLAIMS 1. Attachment plug (1) for attaching linings, bolts, screws, pins etc on a wall, comprising a metal sheet (2) which is bent to form a substantially cylindrical sleeve provided with lugs (3, 4, 5, 6) spaced apart in the longi¬ tudinal direction of said sleeve, said lugs being punched in the metal sheet and bent outwardly in an angle with re¬ spect to the sleeve, c h a r a c t e r i z e d in that the metal sheet (2) consists of spring steel and in that said lugs punched in the sleeve comprise at least two dif¬ ferent lengths of the lugs (3, 5 respectively 4, 6) , the lugs being disposed in the longitudinal direction of the sleeve one after the other and comprising short lugs (3; 4) and long lugs (5; 6) in an alternating sequence. 2. Attachment plug as claimed in claim 1, c h a r a c t e r i z e d in that said sleeve comprises two sets of lugs (3; 5) which are bent in an outwardly di¬ rection from said sleeve and two sets of lugs (4; 6) which are bent in a direction inwardly towards the inner part of said sleeve, said lugs (4, 6) which are bent inwardly hav¬ ing their ends directed towards the inner end of said sleeve and the lugs (3, 5) which are bent outwardly having their ends directed towards the outer end of the sleeve. 3. Attachment plug as claimed in claim 2, c h a r a c t e r i z e d in that each set of lugs com¬ prises at least two different lengths of said lugs (3, 5 respectively 4, 6) . 4. Attachment plug as claimed in claim 3, c h a r a c t e r i z e d in that said plug comprises an inner end portion to be inserted into a hole in a wall etc and an outer portion projecting outwardly a predetermined distance outside the wall, the inner end portion being formed with said lugs (3, 5) which are bent outwardly and the outer portion of said plug being formed only with lugs (4, 6) which are bent inwardly. 5. Attachment plug as claimed in any of claims 1-4, c h a r a c t e r i z e d in that said lugs (3, 5 re- spectively 4, 6) have a cross section form which is plane in the transverse direction. 6. Attachment plug as claimed in any of claims 1-4, c h a r a c t e r i z e d in that said lugs (3, 5 re¬ spectively 4, 6) have a cross section form having a concave or a convex curvature in the transverse direction. 7. Attachment plug as claimed in any of the preceeding claims, c h a r a c t e r i z e d in that the lugs (3, 5) pointing outwardly and the lugs (4, 6) pointing outwardly are bent with a curvature outwardly or inwardly re- spectively. 8. Attachment plug as claimed in any of claims 2-7, c h a r a c t e r i z e d in that the free ends of lugs (3, 5) bent outwardly are convexly rounded, and the free ends of lugs bent inwardly (4, 6) are concavely rounded. 9. Attachment plug as claimed in any of the preceeding claims, c h a r a c t e r i z e d in that the free ends of the lugs (3, 5, 4, 6) are bent at a certain angle. 10. Attachment plug as claimed in claim 9, c h a r a c t e r i z e d in that the free ends of lugs (3, 5) bent outwardly are bent in a certain angle out¬ wardly, and the free ends of lugs (4, 6) bent inwardly are bent in a certain angle inwardly. 11. Attachment plug as claimed in any of claims 2-10, c h a r a c t e r i z e d in that the free ends of lugs (4, 6) bent inwardly terminate at the same distance from the centre axis of the attachment plug (1) . 12. Attachment plug as claimed in any of the preceeding claims, c h a r a c t e r i z e d in that the inner end of the sleeve is formed with lugs (7) arranged peripherally adjacent each other, which are bent inwardly to form a rounded point (8) of the plug, the outer end of said sleeve being provided with an end flange (9) bent outwardly.

Inventors: ENGSTROEM BORIS, ENGSTROEM, BORIS
Applicants: ENGFIX AB
Application year: 1992
Main classification: E04B1
IPC codes: F16B13