EP1672143A2

EP1672143A2 - Reusable modular monobloc formwork for making square or rectangular columns

Info

Publication number: EP1672143A2
Application number: EP05425753A
Authority: EP
Inventors: Mirco c/o Geoplast S.p.a. Pegoraro
Original assignee: Geoplast SpA
Current assignee: Geoplast SpA
Priority date: 2004-12-17
Filing date: 2005-10-24
Publication date: 2006-06-21
Also published as: EP1672143A3; ITPD20040316A1

Abstract

The invention is a new reusable modular formwork for casting rectangular columns, consisting of a plastic panel (M) with various stiffening ribs on the outside (Me), the sides of which are at a 45° angle to enable their juxtaposition up against similar modular formworks of the same height but different widths. There are holes (Mf) in the ribbing around the perimeter of the element for the insertion of means (C) for connecting and locking adjacent formworks. Four modular formworks can be juxtaposed to create a rectangular self-supporting formwork assembley; several formworks can be stacked and locked together to obtain a completed self-supporting assembly of the required height.

Description

This patent relates to the equipment used in construction work and particularly concerns a new type of formwork for making square or rectangular concrete pillars or columns.
Previously-prepared formwork made of sheet metal or wood is generally used to make columns with a square or rectangular cross-section.
Sheet metal formwork is thick and consequently very heavy, however, so its installation often demands the use of a crane or lifting apparatus, or several workers. It needs to be routinely protected against rust and its weight makes it a constant hazard to workers, especially when it has deteriorated and risks causing injuries aggravated by the presence of rust. Its weight also makes it unsuitable for large-scale applications and its useful surface area is consequently very limited.
Wooden types of formwork are also known, consisting of flat planks that are assembled together with the aid of nails, brackets, crossbars and other metal equipment, which may be disposable all reusable.
This patent concerns new reusable plastic monobloc modular formworks with related keys that can be joined together to make a self-supporting formwork assembly for casting square or rectangular columns.
The object of the invention is to produce new reusable monobloc modular formworks and corresponding keys to make square or rectangular self supporting formwork assembley that is easy to assemble and dismantle.
Another object of the new reusable monobloc modular formwork is to make lightweight and stable forms without the need for any further external supporting structures.
Another object of the new reusable monobloc modular formwork is to enable a rapid stripping.
Another object is to prepare formwork suitable for use in casting various sizes of pillar, be they square or rectangular, or with other cross sections.
These and other direct and accessory objects are achieved by the new reusable monobloc modular formwork, which can be attached together with the keys to prepare square or rectangular columns, consisting of linear elements with flat walls and lateral coupling surfaces lying at a 45° angle thereto.
The monobloc modular formwork is made of plastic; it comprises a smooth formwork wall on the inside and has several stiffening ribs on the outside, preferably equidistant, lying both around the perimeter and over the surface of the wall.
This ribbing preferably extends at right angles from the plane of the wall and the coupling surfaces.
Holes are provided in the upper and lower perimeter ribbing and in the coupling surfaces to enable the insertion and rotation of the keys.
These keys consist of a cylindrical body with a handle at one end (preferably placed at right angles to said body), and two or more radial projections at the other end (preferably located at regular intervals).
Four modular formworks are juxtaposed to form a square or rectangular portion of formwork and attached together by means of the keys inserted and rotated in the aligned holes on said coupled modular form works. Several such formworks can be stacked to obtain a self-supporting formwork assembly of the required height and connected to one another by means of further identical keys. Alternatively, four formworks can be stacked vertically and then connected together, after coupling them two at a time, around the pillar's metal reinforcement bars.
Such compositions ensure the vertical stability of the self-supportin formwork prior to casting.
Suitable sloping surfaces are provided on the ribbing on the modular formwork in line with the holes and/or on the radial projections on the keys to prevent any unwanted rotation of the keys and consequent separation of the various modular elements, thus enabling the formworks to be locked to one another.
The characteristics of the new reusable monobloc modular formwork and related keys for making self-supporting formwork assembly for casting square or rectangular columns will be better explained in the following description, with reference to the drawings, which are attached as a nonrestrictive example.
Figures 1 and 2 respectively illustrate two orthogonal views of a modular formwork (M) for use in combination with other similar modular formworks (M), for casting square or rectangular columns.
The modular formwork (M) consists of a plastic panel of generically flat cross-section with coupling surfaces (Me) sloping at a 45° angle to the plane (M1) of said panel, suitable for juxtaposing with similar modular formworks (M), as shown in figure 4a.
Said formork (M) is complete with several stiffening ribs (Mn) on the outside (M2) and further stiffening ribs (Mo) lying around its perimeter.
The ribs (Mn) on the outside are distributed over the whole of said outer surface (M2) of the modular formwork (M).
The ribs on the upper and lower perimeter (Mo) of the panel forming the modular formwork (M) are preferably thicker and wider.
The upper and lower perimeter ribbing (Mo) also provides a surface for supporting or connecting further modular formworks (M) above and below each element (M).
Holes (Mf) are provided in said perimeter ribbing (Mo) and in said coupling surfaces (Me), that are preferably circular in shape and have two or more diametrically opposite grooves (Mf1).
Said holes (Mf) are arranged at regular intervals along the perimeter ribbing (Mo) and the coupling surfaces (Me) and in such a manner that, when several modular formworks (M) are coupled together or stacked, said holes (Mf) in one formwork (M) are exactly aligned with the corresponding holes (Mf) in the adjacent formwork (M).
The distance between the outermost holes (Mf) in each element's perimeter ribbing (Mo) or coupling surface (Me) and the end of the ribbing (Mo) or coupling surface (Me) is narrower than, and preferably half the distance between the other holes (Mf) lying along said ribbing (Mo) or coupling surface (Me) on the modular formwork (M).
The surface on the inside (M1) of the new modular formwork (M) is smooth and preferably treated so as to prevent the concrete from adhering thereto.
Figures 3a, 3b and 3c show three non-restrictive and non-exhaustive examples of modular formworks (M) in different sizes.
Modular formworks (M) of different sizes can be coupled in different combinations to obtain formwork of the required dimensions for casting square or rectangular columns.
The various modular formworks (M) can be connected with straps or, preferably, with specific keys (C).
Figures 5 and 6 respectively illustrate a side view and an axonometric view of such a key (C).
The key (C) consists of a body (C1) with a handle (C2) at one end and two or more radial projections (C3) at the other end.
The body (C1) of the key (C) is generically cylindrical in shape and has the same diameter as that of the holes (Mf) in the perimeter ribbing (Mo) and coupling surfaces (Me) on the modular formwork (M); its length exceeds the thickness of two perimeter ribs (Mo) or coupling surfaces (Me). To be more precise, said body (C1) has a portion (C11) of the end near the handle (C2) that is larger in diameter than the rest of the body (C1).
The handle (C2) at one end of the body (C1) is a portion lying at right angles to the body (C1) and may be shaped (C21) so as to provide a better grip.
The two or more radial projections (C3) at the opposite end of the body (C1) are diametrically opposite one another and preferably in the form of a segment of a ring.
Said radial projections (C3) are of such length and width that they can pass through the grooves (Mf1) in the holes (Mf) in the perimeter ribbing (Mo) and coupling surfaces (Me) on the modular formwork (M) when the key (C) is inserted in said holes (Mf).
A stable connection of the various modular formworks (M) is achieved by inserting said key (C) in the holes (Mf) in the perimeter ribbing (Mo) and coupling surfaces (Me) of the juxtaposed modular elements (M) so that the radial projections (C3) on said keys (C) both extend beyond the holes (Mf), and then rotating said keys (C) so that said radial projections (C3) are no longer aligned with the grooves (Mf1) in said holes (Mf).
Figure 7 shows an example of two modular formworks (M) connected by means of said key (C).
Provision can be made for said radial projections (C3) and/or the plane of the perimeter ribbing (Mo) or coupling surface (Me) in line with the holes (Mf) to lie at an angle so as to induce a compressive force between the two perimeter ribs (Mo) and between the two coupling surfaces (Me) of the juxtaposed modular formworks (M) when the key (C) is rotated.
The keys (C) thus described are equally suitable for the connection of four modular formworks (M) juxtaposed so as to form a tube, or the connection of modular formworks (M) stacked so that one acts as an extension of the other, simply by inserting and rotating each key (C) in the aligned holes (Mf) of the juxtaposed formworks (M).
Figures 4a, 4b and 4c show three non-restrictive and non-exhaustive examples of combinations of various modular formworks (M, M', M") of different sizes allowing rectangular columns in different sizes to be obtained.
The reusable monobloc modular formworks (M) and corresponding keys (C), made as described above to enable the construction of self-supporting formwork assemblies for casting square or rectangular columns, offers considerable advantages.
These modular formworks (M) are lightweight, shock-resistant, easy to transport and easy to assemble simply by inserting and rotating the keys (C) on the perimeter ribbing (Mo) and coupling surfaces (Me) of juxtaposed elements.
The modular formworks (M) enable a rapid stripping of the self-supporting formwork assembly soon after casting the concrete, simply by rotating and removing the keys (C) that hold the modular formworks (M) together.
The self-supporting formwork assembly prepared with the above-described modular formworks (M) and keys (C) need no specific external structures to maintain the alignment of the self-supporting formwork assembly as a whole because, thanks to the use of the keys (C), said formworks are connected together to produce a tubular structure that remains very stable during the casting operations.
Juxtaposing modular formworks (M, M', M") of the same height but different width enables the quick and easy preparation of rectangular self-supporting formwork assembly of the required dimensions.
Thus, with reference to the preceding description and to the attached drawings, the following claims are advanced.

Claims

Reusable monobloc modular formwork for making pillars or columns, characterized in that it consists of a generically flat plastic linear element (M) with a smooth surface (M1) forming the inside wall of the form, while on the outside (M2) there are stiffening ribs along its upper and lower perimeter (Mo) and intermediate stiffening ribs on the surface of the wall (Mn), wherein the sides of said wall include coupling surfaces (Me) sloping at a 45° angle to said wall (M1), so as to enable their orthogonal juxtaposition with other identical modular formworks (M) to form a square or rectangular a self-supporting formwork assembly.
Reusable monobloc modular formwork, according to claim 1, characterized in that the intermediate ribbing (Mn) on the outside (M2) lies at right angles and/or parallel to the coupling surfaces (Me).
Reusable monobloc modular formwork, according to the previous claims, characterized in that the perimeter ribbing (Mo) along the upper and lower edges of the modular formwork (M) are of sufficient thickness and width to enable their coupling with the upper and lower perimeter ribbing (Mo) of an identical modular formwork (M) juxtaposed thereto.
Reusable monobloc modular formwork, according to the previous claims, characterized in that the linear element (M) is designed to be juxtaposed with similar linear elements (M', M") of the same height but different width.
Reusable monobloc modular formwork, according to the previous claims, characterized in that the coupling surfaces (Me) on the sides of the modular formwork (M) are of such thickness and width as to enable their coupling to the corresponding coupling surfaces (Me) of an identical modular formwork (M) juxtaposed thereto.
Reusable monobloc modular formwork, according to claim 1, characterized in that it has holes (Mf) in the upper and lower perimeter ribbing (Mo) and lateral coupling surfaces (Me), said holes being preferably circular in shape with two or more grooves (Mf1) lying diametrically opposite one another, wherein said holes (Mf) are arranged along the upper and lower perimeter ribbing (Mo) and in the lateral coupling surfaces (Me) so that, when several modular elements (M) are juxtaposed or stacked, said holes (Mf) in the various juxtaposed or stacked modular elements (M) are aligned with one another.
Key (C) for use with modular formworks (M), characterized in that it consists of a cylindrical body (C1) with a handle (C2) perpendicular to said body (C1) at one end and two or more radial projections (C3) at the other, wherein said cylindrical body (C1) has the same diameter as the diameter of the holes (Mf) in the perimeter ribbing (Mo) and coupling surfaces (Me) of the modular formwork (M) and has a length that is greater than the thickness of two perimeter ribs (Mo) or two coupling surfaces (Me), and wherein said radial projections (C3) are preferably in the form of a segment of a ring so that they can pass through the grooves (Mf1) in the holes (Mf).
Key according to the previous claim, characterized in that it has said radial projections (C3) lying at an angle.
Reusable monobloc modular formwork, according to any of the previous claims from 1 to 6, characterized in that it is connected to other similar formworks by means of keys as described in claims 7 or 8, wherein said connection assures the stability of the self-supporting formwork assembley.