FR2788541A1 - Rough boxes for permanent concrete shuttering with rigidity obtained by tenons and mortises locked by overlaps - Google Patents

Abstract

Boxes are made from plastic or cardboard sheets and marked with groove axes and box starting folds. They comprise a bottom (1) and four lateral faces (2, 3, 4/5, 6/7) forming a square or rectangular section. After folding, box rigidity is obtained by tenons (8, 10 and 9, 11) and mortises (14, 15) which are locked by overlaps (12,13).

Description

PLANAR DRAFT BOXES FOR LOST FORMWORK

RESERVATIONS.

  The present invention relates to the planar outline of boxes for cof-

  lost reservation reservations by folding a blank cut from a single piece,

  either in corrugated or compact plastics or similar materials or in particular

  corrugated or compact cartons.

  The creation, by the shell, of reservations in floors, slabs and walls ... concrete structures are necessary for the passage

  subsequent sheaths, conduits, pipes, various pipes of the finishing work.

  These reservations are obtained by lost formwork implemented

  before pouring concrete as well on traditional construction sites

  truction than in factories on the pouring tables of precast concrete building elements. In the current state of the art, the most common solutions used for the formwork of such reservations are as follows:

  - use of wood, this consists of making, to measure, to the dimensions

  sions of the reservation, a formwork box also called "anchor box" in wood or plywood with four sides with or without bottom. It will be fixed on the work plan by nailing, gluing or by ligatures to the reinforcements of the concrete irons. These wooden boxes are difficult to dismantle after the concrete has dried. To facilitate removal after setting of the concrete, the technique consists in treating the wooden walls in contact with the concrete with a so-called product.

"stripper".

  This solution is expensive because on the one hand the labor costs

  glass, carpentry work, implementation time, removal after drying, and on the other hand the costs for having specific tools on site,

  storage locations for wood, formwork products ...

  - use of polystyrene, this consists of cutting blocks of poly-

  styrene to the dimensions of the desired reservation. The fixing of these pavers on the work surface, before pouring the concrete, is done by means of

  adhesive tapes or cold glues ...

  This solution is also expensive, in labor the cutting in format being long and delicate, it requires a tool for the work of polystyrene, a large storage space for the blocks of polystyrene

sheltered from bad weather.

2 -

  The release of the reservation after the setting of the concrete is done by-

  ground polystyrene pavers, which in addition to the time of this

  operation, requires making the worktop clean and free of grease

nullates and debris of polystyrene.

  The prefabrication industry also supplies building components.

  precast concrete, slabs, floors, walls ... leaving the polysty-

  re booking locations, which not only gives a

  idea about the difficulties linked to the destruction of these paving stones on the manufacturing site

  cation in industry but also deprives this industry of an opportunity to deliver to the user products with higher added value by delivering objects with empty reservations. Indeed, the receiving customer must first of all get rid of the polystyrene contained in these objects or additional costs of labor, cleaning and waiting time, before

to do their own work.

  The lost formwork boxes of reservations objects of the invention pro-

  posed overcomes the drawbacks outlined above while ensuring better working conditions, time savings and improved safety for workers working on the works before and after pouring concrete.

  The invention consists of a planar box blank for per- formwork

  reservations due by folding a blank in one piece, either plastic or similar, corrugated or compact, or in particular

  in corrugated or compact cardboard, thickness between 2 to 8mm.

  The blanks of the boxes are delivered and stored flat.

  The blanks are produced by cutting and stamping the blank on

  a news. The cutting axes and the grooving axes, i.e.

  these folds are made on the blank of the blank during this press run. The particular configuration of the axes of cuts and folds of the blank

  gives this box its dimensions of length, width and height, its geo-

  cubic or parallelepiped metrics, its method of assembly and its locking system. The assembly and locking, by folding, ensures this box of lost forms its solidity, its rigidity and its good resistance to

  compression without bonding or welding the walls together.

  All folds and assemblies are carried out manually by the operator on the site, without any tools, before the installation and fixing of the -3-

  boxes on the worktop and concrete pouring.

  The invention makes it possible to manufacture boxes of lost formwork from reservoirs.

  Vations, fixed dimensions, square or rectangular sections, from 10 to 50 cm on the side and from 5 to 25 cm in height, making it possible to cover almost all the reservation sizes usually encountered in the building. However, to meet the needs of larger dimensions, it is possible

  to associate several boxes between them.

  The flat bottom of the box gives it a good seat facilitates its fixing on the work plan by means of nails, staples, ligatures, glues, adhesive tapes, permanent magnets ... The invention finds its application on all concrete works both horizontal and vertical The invention allows the rational preparation of the formwork work of reservations by better organization of work. Time savings in manpower, the formwork boxes are ready to use, in the desired dimensions and can be supplied from a supplier of construction materials, as and when required by the site. The invention provides the

  possibility of standardizing the dimensions of reservations, therefore the supply-

  boxes like other materials. The ease of supply and the small footprint of the boxes supplied flat, no longer require

  plenty of storage space.

  The accompanying drawings illustrate the invention

  - Figure 1 shows the developed blank of the blank box for cof-

  lost frages of reservations bearing the axes of the sections in solid lines and the axes of the creases for folding the box in dotted lines. This figure

  is the representation of the box in its delivery form, ie flat.

  - Figure 2 is the perspective view of the box of lost formwork of reservations assembled ready for use. The visible folds and edges are

  solid lines, hidden folds and edges are shown in dotted lines.

  We distinguish in Figure 1 the axes that determine on the blank of the blank.

  - The bottom (1) of the formwork box is provided with two rectangular notches

  opposite sides, each of the four sides of the bottom (1) is extended by flaps, two of which facing each other constitute the side walls (2) and (3) and the

  two others facing each other in alignment with the notches in the bottom (1)

  kill the assembly flaps (12) and (13).

  - The two side walls (2) and (3) on either side of the bottom (1). We recognize

  born, connected to the bottom (1) by a common edge (1/2) the wall (2) itself -4- extended around the common edges (2/4) and (2/5) by the half orthogonal side walls (4 ) and (5), the latter two being held in order, with the assembly tabs (8) and (9) by the common edges (4/8) and (5/9). By symmetry we recognize, connected at the bottom (1) by a common edge (1/3) the wall (3) also extended around the common edges (3/6) and (3/7) by the orthogonal side walls (6) and (7) themselves even standing, in order, to

  assembly tabs (10) and (11) by the common edges (6/10) and (7/11).

  The length of the wall (2) between the edges (2/4) and (2/5), that of the wall (3) between the edges (3/6) and (317) are increased relative to the length of the bottom (1), edges (1/2) and (1/3), about twice the thickness of the blank material. This arrangement allows the flap (12) to be wrapped when folded with

  the walls (4) and (6), the flap (13) with the walls (5) and (7).

  - The side walls (4, 5, 6, 7) are trapezoidal geometry in order to facilitate the mechanical shaping of the box during folding, the four small bases of the trapezoid or folding edges of the walls between (4) and (2 ), (5) and (2), (6) and (3)

  (7) and (3) are shorter by a space substantially equal to the thickness of the material.

  material of the blank relative to the four major bases of the trapezoid or edges

  folding walls between (4) and (8), (5) and (9), (6) and (10), (7) and (11).

  - The four assembly tabs (8,9,10,11) each carry a

  notch (16), they constitute the folding lock.

  - The two opposite flaps (12) and (13) connected to the bottom (1) by an edge

  common two by two (1/12) and (1/13) each have a recess notch

  tangular placed in the axis and of the same width as the bottom notches (1),

  these notches are used to assemble the folding.

  - The bottom notches (1) associated with those of the flaps (12) and (13)

  constitute the mortises (14) and (15) which will respectively receive the lan-

  post guards (8,10) and (9,11) to ensure terminal locking

folding the box.

  - The flap (12) is detached from the side walls (4) and (6), and the lans

  post-guards (8) and (10) by two cutting axes on each side

  of the flap (12) in the blank of the blank.

  - By symmetry the flap (13) is separated from the side walls (5) and (7), and the tongue-tenons (9) and (11) by two axes of cuts made from

  each side of the flap (13) in the blank of the blank.

  The perspective of Figure 2 shows the box ready for use. The cons-

  truction of the box of lost formwork reservations is obtained by folding to -5-

  hand of the blank of the blank without any tool, operating as follows.

  - The flat bottom (1) ensures a stable seat to the formwork box and

  allows its fixing on all supports or worktops.

  - The side walls (2) and (3) are raised perpendicular to the bottom (1), the two flaps (12) and (13) are pushed beyond the vertical towards the bottom (1) and the inside of the box , then the folds are carried out at right angles along the axes of creasing the blank, edges between the lateral faces (2,4) and (2,5),

  even on the opposite side of the edges between the lateral faces (3,6) and (3,7).

  - The device for assembling the box is obtained by creating the

  nons by bending perpendicularly along the creasing axes of the blank to the walls (4,5,6,7) respectively the tabs (8,10,9,11) which once joined together in pairs (8,10) and (9, 11) so that they come back to back to

  form the two tenons which fit into the two mortises (14) and (15).

  - The finish of the folding is obtained by the return of the flaps (12) and (13) in

  the plane parallel to the side walls (4,5) and (6,7), that is to say the plane perpendicular

  ring at the bottom (1), it consists in introducing the tenons (8,10) and (9, 11) into the mortises (14) and (15) up to the point where the notches (16) provided for this purpose hang in the upper part of the mortises. These operations close the two assembly locks (8,10,14) and (9,11,15) which ensure that this box has all its necessary mechanical qualities of resistance to compression

  for the function and its use as lost formwork for reservations.

-6-

Claims (5)

  1. - Flat outline of a box for formwork lost from reservations in concrete structures comprising a bottom with four integral flaps at the periphery, making it possible to make boxes of formwork by lifting the flaps and bringing them together by an assembly lock, The whole cut from a single-piece blank of plastics or cardboard, characterized in that it comprises, - a flat bottom (1) serving as a seat, in the form of a quadrilateral provided in its middle part with two notches acting as mortises (14,15), - flaps of two vertical walls (2) and (3) extend the bottom (1) on two opposite sides around two folding edges, the length of the walls (2) and (3) is greater than the common length of the folding edges with the side of the bottom (1) by a value approximately twice the thickness of the blank blank material, the side wall flaps (4) and (5) standing around a folding edge on either side in a s the length of the wall (2), they are themselves extended two by two around common folding edges by assembly tongues (8) and (9) acting as tenons, - flaps side walls (6) and (7) standing around a folding edge on either side in the direction of the length of the wall (3), they are themselves extended two by two around common folding edges by assembly tabs (10) and (11) acting as tenons, -flaps of two flaps (12) and (13) extend the bottom (1) on the other two opposite sides around two folding edges, they are each provided in their middle part with two notches serving as mortises (14,15) placed in alignment with the notches in the bottom (1), the mortises (14,15) in which the pins are formed after orthogonal folding of the bottom (1) and the walls (12) and (13) of the notches in the bottom (1) and of the notches in the flaps (12,13), - the assembly tongues (8,9,10,11) each carrying a notch (16) forming tenons after folding back to back (8/10) and (9/11) take place respectively in the mortises (14) and (15) and are immobilized there by   through said cuts (16). -7-   2. - Flat outline of a box for lost formwork according to the claim   tion 1, characterized in that the bottom (1) is a parallelogram, in particular   a square, possibly a rectangle.   3. - Draft olarne de can or coffraaes Derdus as claimed -   tion 1, characterized in that the geometry of the side walls (4), (5), (6), (7) is trapezoidal.   4. - Flat outline of a box for lost formwork according to the claims   1 and 2, characterized in that its folding is blocked by a device   "tenons" and "mortise" tabs constituting a mechanical lock without support   hard, no sticking of the various parts of the box.   5. - Draft olane box Dour coffraaes oerdus according to the claims-   1 and 2, characterized in that the flaps of the flaps (12) and (13) are deso-   lidarized side wall flaps (4), (5), (6), (7) and the tongues of the assemblies (8), (9), (10), (11) by cutting axes made in the blank of the draft.