The present invention relates to a spacer for use in combination with an extended support element to carry this at a predetermined distance above a supporting surface on which a concrete floor is to be casted, which support element has a sliding plane surface for sliding movement of a concrete evening device carried by the support element and comprises two longitudinal form stable side walls defining between them a longitudinal space and being provided with a plurality of through- -holes allowing concrete compound to flow into said space, which side walls have horizontal foot portions, each of which is provided with a plurality of holes distributed evenly in a row, the holes in one and the same foot portion being located at a predetermined centre distance d. from each other, and an optional hole in one of the foot portions being located a predetermined centre distance b_ from the nearest hole on the other foot portion.

When casting concrete floors with greater thickness than normal, it is desirable to be able to use support elements forming a sliding plane surface, denoted screeds, with a height less than the thickness of the finished floor so that a free space is formed beneath the parallel support elements, that can be used for pipe laying and reinforcement. Otherwise, i.e. if the support elements extend all the way down to the support surface, pipe-laying and reinforcement must be performed through special apertures in the support elements.

The support element described in the introduction is of a completely new type which offers a number of important advantages over conventional support elements, such as low weight and consequently facilitated handling, quicker and simpler levelling to place the sliding plane surface

at the desired level, reduced crack formation in the finished concrete floor, offers great freedom of choice when inserting trussing irons, and is not limited to casting on the ground but can also be used when casting cassettes and arches. A support element of this new type is described in SE-B-468 097 corresponding to WO 92/16701.

When casting concrete floors on arches, where the floor is relatively thick, it is for several reasons desirable and advantageous to use support elements whose height is considerably less than the thickness of the finished floor. The support elements must then be levelled with the aid of spacers placed between arch and support element to provide support points located suitable distances apart along the support element. Such a support element, whose height is less than the thickness of the finished floor enables considerable material savings in comparison with a support element whose height is equivalent to the whole thickness of the floor.

Furthermore a free space is formed beneath the support element which can be advantageously utilized for pipe laying and reinforcement so that these no longer have to be passed through aligned apertures in the support element. Furthermore, the trussing irons and pipes can be laid first, and then the support elements fitted and levelled with the aid of the spacers. Another advantage is that the range of support elements of the above- described type can be greatly reduced since differences between floors of different thicknesses to be casted are adjusted by means of the spacers and any adjustment screws therein.

The spacers used hitherto have proved unsatisfactory since they impeded some of the pipes to be embedded, neither could they be quickly and efficiently secured to

the support element so that spacers and support element form a rigid and stable construction unit.

The object of the present invention is thus to achieve an improved spacer that can be quickly and simply secured to a support element of the type described, forming a rigid and stable construction unit and that, when pipe laying is to be performed, can be arranged so as not to impede said pipe laying, without the bearing capacity of the spacer being deteriorated despite the fact that it has recesses, is hollow and has low weight.

The spacer according to the present invention is characterized in that it is made in one piece from a sheet-metal blank and has two side sections and a bottom section connecting them, that each side section has a spine portion provided with a crest having a plurality of upwardly directed teeth separated by spaces and having a constant pitch £, and that the crests and their teeth are so arranged in relation to each other and to the foot portions and their holes in the support element that at least one tooth is received in each of four holes when the support element and spacer are brought against each other at right angels, said four holes being located at the corners of a rectangle.

According to a preferred embodiment of the invention said bottom section has at least two adjustment screws for adjusting the level of the slip surface on the support element.

The invention will be described in more detail in the following with reference to the accompanying drawings.

Figure 1 is a perspective view of one end portion of a support element of the type with which the spacer according to the invention is intended to be used.

Figures 2, 3 and 4 are different views from below, from one side and from one end, respectively, of a spacer according to a preferred embodiment of the invention.

Figures 5 and 6 show a top view and side view, respectively, of the spacer according to Figures 2-4 and illustrate how it is anchored to the support element according to Figure 1.

Figure 1 of the drawings shows a support element of elongate, rail-like shape, comprising a bottom member 1 intended to face towards the supporting surface on which the concrete floor is to be casted, and a top member 2 provided with an upwardly facing sliding plane surface 3 on which a concrete evening device shall rest while sliding along the support element in cooperation with the slide surface 3. The support element comprises two longitudinal, form stable side walls 4, 5 which, seen in a cross section of the support element, extend between the top member 2 and bottom member 1. The side walls 4, 5 define a free space 6 between them, which extends continuously between the ends of the support element. The side walls 4, 5 are provided with a plurality of through- -holes 7, 8 distributed evenly over the whole side wall in several horizontal rows. Each hole 7, 8 is sufficiently large to allow concrete to penetrate through the side walls 4, 5 into the space 6 and collect there, and the number of openings 7, 8 is sufficient and their distribution such that the entire space will be filled with concrete when the support element is embedded in the concrete, before this has had time to solidify. The term "form stable side walls" means that they are sufficiently strong to carry the weight of said concrete-evening device without becoming deformed. In the embodiment shown the side walls 4, 5 are inclined in relation to each other to form an acute angle. The outward slope of the

side walls from the top member allows the concrete to flow more easily through the holes. The inclined side walls 4, 5 suitably form an acute angle of 25°-90° with each other, preferably 30°-60°. The side walls 4, 5 are permanently joined in the top member 2 to form a form stable unit. The bottom member 1 comprises a foot portion 9, 10 at each side wall, said foot portion 9, 10 being permanently joined to the side walls 4, 5 and protruding away from the space 6. The foot portions 9, 10 are also provided with a plurality of through-holes 11, 12 permitting concrete to penetrate through them to the lower sides when they have been adjusted, thus ensuring that they are fixed a certain distance above the supporting surface. The holes 11, 12 have predetermined diameter so that side portions 15, 16 are left in the transverse direction of the support element. It will be understood that the holes 7, 8, 9, 10 offer considerable savings in material and reduction in weight. However, the space 6 gives the greatest reduction in weight in the support element. The support element is preferably manufactured out of a flat sheet-metal blank which is bent so that the foot portions 9, 10 and side walls 4, 5 converge into each other at the folding lines. The transition or cam 13 between the side walls 4, 5 can be designed in various ways to form either the entire top member 2 or a part of this. In the embodiment shown the cam 13 forms a part of the top member 2, which also includes a second part in the form of a non-deformable rail-like body 14 which is arranged above and firmly anchored to the cam 13. In the embodiment shown anchoring is achieved by the cam 13 being shaped with a longitudinal groove 17 and the body 14 then has a lower part 18 with a thickness corresponding to the width of the groove 17 so that the rail 14 can be fitted in the groove 17 and is held there in a firm engagement.

The foot portions 9, 10 have a predetermined width a. (see Figure 5) and the centre distance b_ between an optional hole 11 in one foot portion 9 and the nearest, i.e. opposite, hole 12 in the other foot portion 10, is predetermined for support elements 20 pertaining to the same type, which is normally dependent on the height of the support element.

Figures 2-4 show a spacer 30 according to a preferred embodiment of the invention, for use with a support element 20 of the type described above. The spacer 30 is manufactured in one piece from a flat sheet-metal blank bent along two parallel folding lines 31, 32 to form two side sections 33, 34 and a horizontal bottom section 35. The spacer 30 is symmetrical about the longitudinal vertical centre plane. Each side section 33, 34 has a substantially semi-circular recess 36 arranged so that the side section 33, 34 has two leg portions 37, 38 spaced from each other and located at the ends, the leg portions being connected by a spine portion 39. In the embodiment shown the bottom section 35 is restricted to two foot portions 40, 41 connecting two opposite leg portions 37, 38 together and forming an opening or free passage 42 between them. Depressions 43 are provided in the leg portions 37, 38 and extensions of the spine portions 39 forming sections in order to give the side sections 33, 34 increased bearing strength and rigidity. This in turn means that the recesses 36 and opening 42 can be made relatively large, that material savings can be obtained and the spacer 30 becomes lighter. The foot portions 40, 41 are also provided with reinforcing depressions 44.

The spine portion 39 of each side section comprises a crest 45 with a plurality of upwardly directed teeth 46 that can be bent down and retained in locking position. Between the teeth 46 are wide spaces 47, each having a

horizontal bottom edge 48. The space 47 is adapted to the width of the inner and outer side portions 15, 16 on each side of every hole 11, 12 in a foot portion 9, 10 seen in transverse direction of the support element 20 so that these side portions 15, 16 can easily be received in the spaces 47. The distance c_ between the crests 45 of the two spine portions 39, measured at the base 48 of the crests 45, is predetermined and adapted to said centre distance d. between two neighbouring holes 11 or 12 in one and the same foot portion 9 or 10, so that said crest distance e is a whole multiple of d_, i.e. c_ = ni • _, where n^ is preferably an integer between 1 and 3 depending on the magnitude of d.. The pitch £ of the teeth 46 is constant and adapted to the centre distance b. of the support element 20, so that is a whole multiple of the tooth pitch £, i.e. £) = n2 • £, where TΪ2 is an integer, preferably between 3 and 8. The width of the space 47 is preferably the same as that of the teeth 46, measured at the base of the crest. In the embodiment shown the tooth pitch £ is so small and the holes 11, 12 in the foot portions 9, 10 so large seen in the transverse direction of the support element 20, that two teeth 46 will be received in each hole 11, 12.

The foot portions 40, 41 are provided with circular holes 49, the edges of which have been shaped for thread engagement with adjustment screws 50. The vertical position of the spacer and support element is altered by turning the screws 50 in one direction or the other so that the sliding plane surface 3 is adjusted to the desired level.