EP3361037B1 - Profile system for aluminium and pvc door sash

Info

Technical Domain: Elements of external joinery with opening system and opening systems for external joinery

The invention relates to an assembly of aluminium profiles and PVC intended for doors that have the sash covered with a sheet of aluminium of 1-4 mm in order to eliminate deficiencies in classic PVC doors with the sash covered.

Technical Status:

At present, current systems of PVC doors are clad with aluminium panel by sticking to traditional PVC profile. This method has a number of deficiencies among which the most important and difficult to eliminate is the distortion due to the effect of differential expansion between aluminium sheet and PVC profile, the tape or adhesive bonding taking over the difference only in a limited capacity.
EP 2 933 422 A1 discloses a window frame comprising PVC and aluminium profiles being combined together with clipping means.
The trend for new elements of PVC in general and doors, is to be done with constructive depths increasingly higher to ensure an insulation coefficient as good as possible. But this causes a low static resistance because the elements are not capable of taking loads of stress. Thus, important deformations are occurring, making them virtually unusable.
Traditional PVC door system with the covered sash has a major drawback due to differences of expansion coefficients of the materials that come in contact (aluminium and PVC) - bending the door leaf when extreme temperatures are achieved - that is very high or very low temperatures on the external side of the door leaf.

Major disadvantages:

1. The door's curvature is more pronounced when the metal inside of the section profile is small compared to the size of the PVC so that the PVC has an important influence on the structure of the profile and the profile's static.
2. As a PVC profile gets massive - i.e. large construction depths, the more the problem grows - so the amount of metal used must be increased to ensure the stability of the door leaf. Once increased the amount of metal, the coefficient of thermal insulation will decrease making practically useless the increase of PVC profile.
3. The corners of a classic PVC door are relatively unstable where metal reinforcement is discontinuous - even using welded corners - stability of this region depends on the combination between the structure of PVC and the metal.
4. In the joining area between the sheet of aluminium and PVC profile appears an unaesthetic area, firstly caused due to the slightly curved structure of the profile in that area and secondly caused by errors of overlapping the aluminium sheet over the door sash.

Technical problem: The technical problem solved by the invention is to achieve a set of profiles, one of aluminium and one of PVC, that confer mechanical stability and resistance to thermal stress - similar to aluminium doors - and that also provide thermal insulation similar to or better than a classical PVC doors.

Invention exposure:

The achieved invention was used on system Profine MD88, but it can be used on any other system of PVC profiles currently on the market. The present invention provides a profile assembly according to claim 1.
The combination of aluminium profiles (2,3) has a generally rectangular form, achieved with a pronounced thermal break(4). Specific are channels where the PVC profile (1) is clamped. The combination of aluminium profiles (2,3) is assembled at the corners by welding or other mechanical joining and forms a continuous frame, which is the basis of the door.
The PVC profile (1) is designed to cover the combination of aluminium profiles entirely, except the outside - where the combination of aluminium profiles plated with the aluminium sheet (8) comes in contact with the outside. Such direct contact is eliminated between the PVC and the outside part of the door.
To achieve the door leaf, several steps are to be taken:

1. creating the PVC frame from a PVC profile (1) by the traditional method of cutting, milling, welding.
2. creating the aluminium frame from aluminium profiles (2, 3) and thermal break (4) by cutting, milling, mechanical joining.
3. Combining the two frames by clipping and screwing.
4. Making the panel by combining with glass (10)(optional), with filling (9) and aluminium plates (8).

Advantages:

1. A door with a high stability, deformation being minimized; the outside the door is completely aluminium,
2. The aluminium frame ensures the stability of the door. The amount of PVC being lowered carries little influence on the door.
3. The door reinforcement is removed, the role being taken over by an aluminium frame.
4. The profile system has a coefficient of thermal insulation similar to the classic PVC due to the filling within the whole profile.
5. It decreases the amount of PVC used at approximately 20-30% compared to a traditional profile.
6. It eliminates the use of weld brackets - expensive items.
7. Overall results in a high-quality door - covered door leaf, high strength, improved thermal stress resistance, higher insulation factor and also at a lower cost.

Figure description:

Figure 1 is a section through the door, realized with invented profiles in the threshold area (11) and Figure 2 in the frame area (14+ 15), we distinguish:

PVC profile (1) with clipping elements (5, 6) in the inside of the door
the aluminium profiles (2, 3) with thermal break(4) with the appropriate channels for clipping from the metal side
Fastening screws (7)

The other elements are common with the doors that have the sash covered - sheets of aluminium or another material (8), filling (9) with different densities of materials, insulating glass (10), threshold (11), gasket system (12, 16) dropper (13), the frame (14), aluminium cover for frame(15).