ARRANGEMENT FOR THE PRODUCTION OF LONGITUDINAL SCREED SLABS CONSISTING OF CONCRETE

Abstract: Arrangement for ensuring in connection with the production of concrete screed beams for concrete floors or similar devices good linerarity of the product when casting in accordance with the so-called battery method. On a bed of beams (1) pipes (2) with a certain degree of levelling (3) are placed. In the mould the beams (1) become the underside whereas two nearby pipes (2) become the side walls. The arrangement consists in a plate (5) between two beams (1). The plate is located and shaped in such a way that the T-shaped rail (4) at the bottom of the pipe fits into a recess (6) in the plate. In this way the pipes are aligned, which is the necessary condition for ensuring good linearity of the product.

Description: Arrangement for the production of longitudinal screed slabs consisting of concrete The Swedish patent application 8001 63-7 describes a method for producing concrete floors of high quality as regards planeness and rational construction. With this invention use is made of slide tracks for the vibrating beams employed in the process of producing the floor, by way of permanent moulds. By providing the slabs with either holes or both holes and brackets continuous reinforcement can be achieved, which means that shrinkage cracks do not arise in the floor along these slabs. In producing these slabs a number of problems have been encountered all of which could be solved with the aid of generally known technology (e.g. concrete grades suitable- or the hard wear). One problem, how¬ ever, has proved to be of considerably greater complexity. It relates to the fact that when casting the slabs, which is done in so-called battery moulds, the slabs must be linear. The difficulty consists partly in the fact that it is difficult to produce moulds of sufficient linearity and in that after repeated use the moulds developed a non¬ linear shape due to handling. The present invention proposes an arrangement enabling production with the aid of cheap moulds suitable for imparting good linearity to the slabs. Moulds can be produced from thin metal sheeting bent to the required cross-sectional shape. The sections are then connected by point- elding. This gives rise to. heat stresses causing deformation of the sheets with disastrous consequences for the use cf the resulting slabs. Also injection-moulded aluminium has been tried but after handling the condition of this product became quite bad. Once this was the case it was less possible to produce correct slabs. In addition aluminium is, after all, subject to the disadvantage that it is attacked by concrete, so that the surface of the product becomes rough. It has. proved possible to produce good quality slabs by the so- called battery process. The latter is characterised in that several slabs are simultaneously produced in a large mould. As a result the moulding costs and the moulding work are reduced. However there is still the problem of making these slabs linear. This has been solved in accordance with the invention by shaping the slabs with the aid of parallel pipes close to one another. In the mould the outer sides of these pipes become the lateral boundary surfaces for the concrete. By placing these pipes on a bed of beams, one also achieves, owing to the beams, a lower boundary surface. The bed of beams consists of a frame of strong beams, whereby the length of the frame may amount to 5-10 metres and the width to 1-2 metres. The choice may be made entirely according to the capacity of lifting devices at the place of work (trucks or overhead cranes). Within the frames beams extend at equal distances, i.e. parallel to the longitudinal sides. The pipes are then placed in such a way that the beams constitute the underside of the mould. The invention now aims aτ an arrangement by which the pipes are secured and aligned in such a way that the linearity of the pipes is at least as good as that of the bears. As regards the pipes, the cross- section of which is nearly circular, that part of the periphery which is to form the base is levelled somewhat. This levelling operation is effected between 30- 0 degrees of the centre angle. At the centre of this levelled face a rail is fixed which consists in an upside-down T. Eowever, the continuity of the rail is broken by gaps at equal distances. These breaks occur e.g. at a rate of one per metre and with a length of 5 cm. This can be varied within wide limits, and the dimensions given at this point are mentioned only to facilitate comprehension of the function. Cn the bed of beams and between the beams are placed, at the same distances as the breaks in the rails plates, the top edges of which are located edge in edge with the top edges of the beams. The plates are provided with a Y-shaped recess with the opening so arranged that the web of the T-shaped rail fits inside the Y-shaped recess. The expanding part of the Y-shapes is used for controlling the rail, in case non-linearities in the pipe may have prevented simple insertion. Figure 1 shows a cross-section illustrating the function of the above-named rail and the recessed plate. ( ) are two adjacent beams. On top of these beams is located a pipe (2) with a levelled part of the periphery (3)« Attached to this pipe can be seen the T-rail (4) which, subject to certain breaks, extends along the pipe (2). The plate (5) is provided with a Y-shaped recess (6) subdivided into the inner section (7) and the expanding outer section (θ). Figure 2 shows the plate by itself in a different projection, use being made of the same reference numbers as in the previous case. It is of course most important that the bed of beams is made of strong beams and that the planeness is accurately adjusted. The entire bed of beams is then placed on three or several bearing brackets which in turn are provided with vibration- enerating devices, all with a view to ensuring satisfactory casting.

Claims: Patent claim An arrangement for casting in a mould of so-called battery design longitudinal concrete bodies with a high degree of linearity, the moulds consisting of pipes of substantially circular cross-section, these being placed on top of beams which, within a frame, extend parallel to the longitudinal sides, whereby the beams constitute the lower and two parallel pipes constitute two lateral boundary sides in the process of casting, characterised in that the underside of the mould pipes is levelled and provided with a longitudinal rail of upside-down T-shape, which is cut out over a certain length at several points and at mutually identical distances and in that a plate with a Y-shaped recess is placed between the top edges of the beams and at the same distances as the cut out rails, the recess matching the leg of the T-rail. Oi PI AMENDED CLAIMS (received by the International Bureau on 26 October 1982 (26.10.82)) An arrangement for casting within a mould of so-called battery design longitudinal concrete bodies (9) with high linearity, the moulds consisting of pipes (3) with substantially circular cross- section, which are placed on top between beams (1) extending within a frame parallel to the longitudinal sides of the frame. The beams constitute lower and two parallel pipes (3) constitute lateral boundaries of the mould. The invention is characterised in that the substantially circular cross-section of the mould pipes is modified in is lower part to such an extent that the distance between two beams is bridged by a levelled section (ll) and provided on the underside with a longitudinal r.ail, the cross-section of which is an upside-down T (4). The course of the rail along the pipe is broken at a number of points at mutually equal distances. Between the beams are fixed plates provided with a Y-shaped recess. The plates are secured in such a way that all openings of the recesses point the same way in the longitudinal direction of the beams. The plates shall in partiαular be so located that their upper surface is in the same plane as the upper surface of the beams. The distance between the plates shall be the same as between the breaks in the pipe rail. The pipes are then positioned between the beams and the end faces of the rails are pressed against the recesses in the plates. As a result the pipe rail is pressed into the inner part of the recess, whereby the pipe is controlled both in the vertical and horizontal direction. -BUREA OMPI C EDITORIAL NOTE The applicant failed to renumber the amended claims in accordance with Section 205 of the Administrative Instructions. In the absence of any specific indication from the applicant as to the correspon¬ dence between original and amended claims, these claims are published as filed and as amended.

Inventors: JOHANSSON LENNART, LJUNGKVIST STIG-AOKE, JOHANSSON, LENNART, LJUNGKVIST, STIG-AOKE
Applicants: VM PERMABAN AB
Application year: 1982
Main classification: E04G21
IPC codes: B28B7, E04G21