US 3494088 A
Description (OCR text may contain errors)
Feb. 10, 1970 M. KORNER 3,494,083
CONNECTING ANCHORS FOR MULTIPLE LAYER CONCRETE PANELS Filed Feb. 6, 1968 3 Sheets-Sheet 1 Feb. 10, 1970 M. KGRNER 3,494,088
CONNECTING ANCHORS FOR MULTIPLE LAYER CONCRETE PANELS Filed Feb. 6, 1968 3 Sheets-Sheet 3 United States Patent 3,494,088 CONNECTING ANCHORS FOR MULTIPLE LAYER CONCRETE PANELS Manfred Kiirner, Karlsruhe-Durlach, Germany,
assignor to Thor Waerner Filed Feb. 6, 1968, Ser. No. 703,414 Claims priority, applicatigrli Ge6rmany, Feb. 14, 1967,
Int. Cl. E04c 5/03, 2/06 US. Cl. 52410 3 Claims ABSTRACT OF THE DISCLOSURE A wave-shaped connecting anchor positioned between two concrete members and an insulating plate, the anchor being in the form of a closed wire loop having crests and peaks which are in the concrete and extend through the insulating plate.
There are already known prefabricated concrete parts as multiple layer panels which are also called sandwich panels and which are mainly destined for exterior walls of buildings. They comprise, for instance, a bearing reinforced concrete panel having an approximate strength of to 12 cm. the so-called interior layer or interior panel, a face panel of about half the strength, also consisting of reinforced concrete, which as exterior layer or exterior panel is destined for the outside of the building, and an approximately 3 to 4 em. strong intermediate layer of insulating material such as Styropor or similar. Since the insulating layer will not be able to take up the forces occurring, the exterior panel and the interior panel which are usually reinforced by woven steel fabric, are connected to each other by means of one or several steel anchors. The same will not only have to support the dead weight of the exterior Panel at the bearing interior panel during transportation and in the final building, but they will also have to receive the stresses resulting from differences in temperature between said two side panels which, in extreme cases, may amount to as much as 50 C.
Corresponding technical literature recommends the center or the center of gravity of the panels respectively as the most favorable location for the positioning of the connecting anchors. However, multipie layer panels are known providing for several anchors beyond the center, for anchors in every corner of the panels, or for anchors distributed all over the panel surface. The anchors already known are of double T shape, L shape or in the form of an angle with adjacent clamping legs to be clamped into the woven steel fabric of one of the two concrete panels. There are also known less heavy anchors in the form of hairpins or needles, provided with toothed edges. Since the insulating layer does not offer any protection againstcorrosion, the connecting anchors will have to be made from corrosion and acid resistant material such as special steel. Furthermore, light weight connection nails of synthetic material are also known.
The present invention provides for anchors to connect multiple layer reinforced concrete panels of the type described above and for multiple layer panels equipped with said anchors, in which the forces occurring will be received in a particularly favorable manner, while their assembly will be as simple as possible.
The connecting anchor according to the present invention is characterized in that it comprises a wavy or jagged ring bent from wire in the form of a crown, which, preferably, has four wave crests or jags each towards each of the two sides. But the ring may also have any other number of jags, for instance, 3, 6, or 8. Due to the bridges of this crown-like ring directed towards all sides,
stresses acting into all directions especially in the case of thermal expansion will be received in an ideal manner. In particular, said multi-jagged ring will receive directly horizontally and vertically acting forces. Apart from final installation of the composite panel, this will also be important with a view to transportation, since during shipment the panels may be placed without any risk both on their short or on their long edges.
According to another feature of the present invention the total height of the waves or jags of the ring or crown anchor is greater than the distance of the reinforcement of the two concrete panels consisting for instance of woven steel fabric, by such an amount that it will be possible to insert additional steel, for instance, simple straight steel rods, between the jag tops and panel armouring, said additional steel anchoring the connecting anchors against the armouring of the two panels and thus even the latter against each other.
According to the present invention an especially simple method to produce the anchors mentioned above is to start with bending a wire into a plane polygon, preferably a square, in which the two wire ends are overlapping on one side of the polygon. Then the corners together with parts, preferably the halves of the adjacent sides are bent out of the original plane by approximately into the same direction. Thus production is effected by the minimum number of simple steps. In the case of panels in the form of an oblong rectangle the production of the anchors may be based upon an oblong rectangle similar to that of the panel shape instead of a square.
According to the present invention the anchor ring will be favorably inserted in the production of composite panels such that the center of gravity of the panels will be located in the center of the same and the anchor jags in planes partially parallel to one pair of edges, partially parallel to the other pair of edges. This will result in especially favorable reception of forces without involving any detrimental moments. It is not important which side of the jagged ring is located in one of the panels and which in the other, so that in this respect any errors in the production of composite panels are not liable to occur. Insertion of the anchor between the woven steel fabrics will also be extremely simple, as any exact mutual position will not have to be observed, because the additionally inserted steel will be able to bridge distances of any size.
Further details of the present invention may be seen from the following specification and claims.
The drawings show a preferred embodiment of the present invention; in the same FIG. 1 shows a perspective view of a connecting anchor,
FIG. 2 shows a connecting anchor according to FIG. 1 in an intermediate production step,
FIG. 3 is a cross section through the center part of a multiple layer panel according to the present invention,
FIG. 4 is a top view of a multiple layer panel according to the present invention.
FIG. 1 shows a connnecting anchor 1 bent from special steel wire in the form of a jagged ring with 4 jags towards each side. The jag tops A, A and B, B of one side are located in pairs opposite each other and, in addition, on a circular line. The same applies to the jag tops A A and B B, of the other side.
In the production, as shown in FIG. 2, first a square is bent from the wire, the wire ends 2 and 3 overlapping each other side by side for a certain length. They may be lying loosely side by side or they may be connected to each other by welding, winding or similar. It will even be possible to butt-joint the wire ends and to weld the same in this position. Accordingly, the square may also be composed of several wire pieces.
After the square has been made, the corners A, A, B, B together with the adjacent lateral parts 4 and 5 and the bisecting points A A' B B' of the square sides are bent out of the plane of the original square into one direction by 90 so that they will occupy the position identified by a line of dots and dashes. All bending points are subject to angles of 90. This is the final shape of the connecting anchor. But it will also be possible to extend or to compress the jagged ring to increase or reduce the angles. However, in each case, the total height h of the jags will have to be greater than the distance of the concrete panel armouring which the anchor is to connect, by such an amount as to enable bracing by means of the additional steel 9.
As already mentioned, the crown-like jagged or wavy ring of "the connecting anchor may also have more or less than 4 jagged Waves.
Production of the multiple layer panel according to FIGS. 3 and 4 preferably starts with planely covering a shuttering panel =6 which has been smoothly polished, grooved or similar according to the desired surface form of the exterior wall. The woven steel fabric 7 of the exterior reinforced concrete panel 8 is placed upon the shuttering panel 6 by means of distance pieces, and the connecting anchor 1 is inserted into the center of the panel also by means of distance pieces such that the jag tops A and B are projecting through the woven steel fabric 7. Connection between the anchor 1 and the woven steel fabric 7 is effected by additional steel 9 arranged parallel and/ or crosswise. Now, the first layer-usually the exterior or face panel-is concreted, Naturally, the interior panel may also be concreted first and on the bottom.
Thus the insulating layer 12 shall be positioned, the jags of the connecting anchor 1 being points projecting through said layer. This may favorably be effected without any detrimental deformations with, for instance, plastic foam panels which are usually 3 to 4 cm. strong measuring 100 x 50 cm.
Subsequently the woven steel fabric armouring 10 of the second concrete paneL-in the embodiment according to IFIG. 3 the bearing interior concrete panel 11-is again provided with distance pieces in which case, regarding its connection 'with the connecting anchor .1 by means of additional steel 9 arranged parallel and/ or crosswise, the same will be applicable as for the face panel 8. After concreting upon said layer 11 the result will be a prefabricated three layer element of maximum stability and at the same time of free mutual mobility of the two concrete panels 8 and 11 around the center of gravity as a fixed point.
As may be seen from FIG. 4, the struts 4 and 5 of the connecting anchor 1 which are at right angles towards each other and which are located in planes parallel to the panel edges, will receive both the vertical and the horizontal forces of pressure and tension.
In addition and if so desired, both panels of the prefabricated structural element may be connected by nails provided with teeth or similar 13 of a type already known and made from special steel or any other corrosion resistant material 'within the area of the center anchor, but also in any other location such as in the corners.
The construction may also be modified otherwise without extending beyond the scope of the present invention. In particular, the anchor ring may consist of several independent parts to be assembled when making the composite panel such that the same technical effect will be obtained by them jointly as in the present embodiment. Several angular anchors of the type above may also be arranged in a circle around the center of gravity of the panels.
What I claim is:
1. A connecting device for a plurality of concrete members including an insulating plate between said concrete members comprising:
(a) an anchor alternately intersecting said insulating plate,
(b) said anchor being positioned in said concrete members on each side of said insulating plate,
(c) said anchor being in the form of a closed wire loop forming an opening having an axis substantially perpendicular to said concrete members,
(d) said anchor including plural pairs of spaced parallel arcuate segments of wire, one pair being disposed in substantially right angular relationship to a second pair of arcuate segments the contiguous ends of the segments being interconnected and forming peaks pointing in one direction and positioned in one of said members, each pair of segments also forming crests pointing in the other direction and positioned in the other of said members.
2. A connecting device as defined in claim 1 including reinforcing rods in said members.
3. A connecting device as defined in claim 1 wherein the points of said crests are coplanar and the points of said peaks are coplanar, said planes being parallel to said plate.
References Cited UNITED STATES PATENTS 3,237,357 3/1966 Hutchings 52 --4l0 3,338,017 8/1967 Ernst 52685 FOREIGN PATENTS 14,328 2/ 1926 Netherlands. 299,433 7/ 1917 Germany. 128,390 6/1919 Great Britain.
HENRY C. SUTH-ERLAND, Primary Examiner U.S. Cl. X.R. 52648, 650, 712