Composite framing profile
The present invention relates to a composite framing profile.
Composite framing profiles are known comprising an outer metal portion having structural aesthetical and atmospheric agent resistant purposes, an inner wooden portion having aesthetical and thermal insulation purposes and an intermediate plastics portion having thermal insulation and elastic connection purposes between the metal and wooden portions. Such composite framing profiles proved to be effective both from the aesthetical view point, since they enable the assembly frame, seen from inside, to have the traditional appearance of wooden frames, and from the functional view point, since they present a high resistance to atmospheric agents, due to the external metal portion, a high non- deformability due to the possibility of mutual longitudinal sliding of the composing portions, and therefore of absorption of unavoidable differences of thermal expansion, and a sufficient degree of thermal insulation, due to the presence of the plastics portion which insulates the outside from the inside.
Generally the coupling between the inner wooden portion and the plastics portion is steady and is obtained by joint
and glueing, whereas the coupling between the outer metal portion and the plastics portion is obtained by. snap engagement or clamping through a cold deformation of the edges of this metal portion. The instant invention particularly relates to a composite framing profile in which the coupling between the metal outer portion and the plastics portion occurs by snap engagemen .
The known solution of this kind must satisfy at the same time two contrasting requirements: on one hand the need of obtaining a snap engagement compels to realize the plastics portion with a material enough elastic to enable this snap engagement; on the other hand the need of ensuring the maintenance of this snap engagement compels to realize the plastics portion with a material enough stiff to prevent the mutual disengagement due to unavoidable mechanical stresses to which the portions are subjected, particularly due to the larger thermal dilations of the metal with respect to the wood. Up-to-date these contrasting requirements have been reconciled by resorting to a compromise solution, which has been empirically reached in the most cases through a series of attempts which however require the rejection to the
optimal results which can be reached in order to satisfy each requirement individually considered. Furthermore, since the compromise solution between the flexibility of the plastics material to enable the snap engagement with the metal material and its stiffness to ensure the maintenance of such an engagement are necessarily related to the value of temperature, unavoidably a solution which is effective for a temperature cannot be likely effective for different temperatures. A main aim of the invention is to overcome these limits of the prior art and to realize a composite framing profile of the kind above referred to, which enables, within a wide range of temperatures pratically corresponding to the several climatic conditions in which the assembly frame must be used, an easy snap engagement between the plastics portion and the metal portion during the constructional stage of the composite profile, and a sure maintenance of the so obtained engagement during the utilization stage of the same composite profile. This aim and further aims which will be apparent from the ensuing description are attained according to the invention by a composite framing profile, formed by the coupling of an outer metal portion, of an inner wooden
portion and an intermediate plastics portion as described in claim 1.
The present invention is hereinafter further clarified with reference to the enclosed sheets of drawings in which: Figure 1 shows in cross-view a frame using, for the fixed door and the movable door, composite framing profiles according to the invention, Figure 2 schematically shows one of these framing profiles in a second embodiment, Figure 3 shows it in a third embodiment. Figure 4 shows it in a fourth embodiment, Figure 5 shows it-in a fifth embodiment, Figure 6 shows it in a sixth embodiment,
Figure 7 shows in the same view as figure 1 a composite framing profile using different parts which ensure a better thermal insulation between the external ambient and the inner ambient.
As can be seen from the figures the composite framing profile according to the invention is obtained through the coupling of three elements. The first element consists of a metal profile 2, preferably of extruded aluminium which, apart from slight differences which will be better evidentiated in the following description, can be used to
realize the fixed frame or the door of the assembly frame. It comprises a tubular body 4, from which a flat wing 6 projects, directed outwards and forming the visible surface of the composite profile according to the invention. At the free end of the wing 6 a groove 8 is provided facing the inside of the assembly frame and suitable to house, as it will be better clarified, a gasket 10 for the external sealing, cooperating with a double glazing unit.
From the wall of the tubular body 4 opposite to the wing 6 four paralel wings, more precisely two external 14,16 and two internal 18,20, project towards the assembly frame. Both the wings 14,16 -present at the free end, on the surface facing the external wing, a substantially triangular cross section rib 22, and furthermore the external wing 14, nearer to the double glazing unit 12, that is the external wing shown in the upper part of the sheet of drawings, presents a further rib 24 on the surface opposite to that provided with the rib 22.
More precisely each rib 22 has a larger wall, having a smaller angulation with respect to the plane of the same rib 22 and a smaller wall, sunbstantially perpendicular to the larger wall.
The second element of the composite framing profile
consists of a wooden profile 26. It is provided with two longitudinal parallel grooves 28 for housing and engaging corresponding ribs 30 foreseen in an intermediate plastics element 32 connecting the metal profile 2 and the wooden profile 26. Each groove 28 has substantial trapezoidal section, with the inner surface, that is with the surface nearer to the other rib 30, which is parallel to the corresponding surface of this and with the external surface inclined so as to converge with the internal one towards the bottom of the same groove.
The wooden profile 26 is also provided with a third longitudinal groove 34 suitable to house a gasket 36, which, in the case the profile forms the door, ensures the sealing between the door and the fixed frame, whereas in the case the profile forms the fixed frame, it ensures the sealing between this and the pallet or the masonry 38.
The third element of the composite profile consists, as already said, of a plastics profile 32 connecting the outer metal profile 2 and the inner wooden profile 26. This plastics profile 32 comprises a middle portion 40, from which two ribs 30 project towards the wooden profile 26 and four wings 42,44 project towards the metal profile 2, that is in the opposite direction. Each rib 30 has a cross
section substantially complementary to the section of the corresponding groove 28 of the wooden profile 26.
The outer surface of each groove 30 is wholly smooth and inclined according to the inclination of the corresponding surface of the groove 28, whereas the inner surface is provided with a plurality of longitudinal parallel streakings which makes easier the arrangement of the same rib into the corresponding groove 28 and the steady engagement between the two by means of suitable adhesives. Each external wing 42 of the plastics profile 32 facing the metal profile 2 is slightly inclined so as to converge towards the other external wing and presents on the outer surface a groove 46 complementary to the triangular rib 22 of the corresponding wing 14, 16. Furthermore the inclination of each wing 42 is such that its outer surface forms an inclined plane, along which the triangular rib 22 can slide, as it will be better clarified, to make easier its snap engagement with the corresponding groove 46. Likewise to the ribs 22, the groove 46 has a larger wall, slightly inclined with respect to the wing 42 and a smaller wall, substantially perpendicular to the larger wall.
Finally the heigth of each external wing 42 is such that, in the engagement configuration shown in fig. 1, its
free edge forcedly adheres to the outer surface of the corresponding wing 18,20 thus being in pre-loaded condition and opposing in such a way the disengagement between the two profiles 2 and 32. The centered position of the profiles 2 and 32 in condition of mutual engagement is also ensured by the rest of the outer surface of the inner wings 44 of the plastic profile 32 against the inner surface of the inner wings 18,20 of the metal profile 2. The metal profile 2 of the frame presents a groove 48 housing a gasket 50 which ensures the sealing, when the frame is closed, between the door and the fixed frame of the assembly frame, and limits a longitudinal chamber 52 between the two. As already said, the external wing 14 of the metal profile 2 of the door presents a rib 24 facing the double glazing unit 12. A corresponding groove 54 of a plastics profile 56 engages with this rib 24, housed in a wooden profile 58 having the function of glass-block and provided, in correspondence of the edge near the double glazing unit 12, with a sealing gasket 60.
In order to ensure an effective insulation against the noises and wind, the gasket 60 is provided with a fin 62
extending so as to rest with its free edge against the wall of the tubular body 4 of the metal profile 2.
It is also foreseen that the plastics profile 56 housed in the profile 58 is provided with a plurality of spaced apart grooves 54 which enable the choice for the engagement of the ribs 24 according to the khickness of the double glazing unit 12 and therefore according to the distance which must be maintained between the profile 58 and the double glazing unit 12. In order to assembly the composite profile according to the invention, firstly the wooden profiles 26 are coupled with the plastics profiles 32. Such a coupling occurs in correspondence of the ribs 30 of the profile 32, which are inserted into the corresponding grooves 28 of the profile 26 and are firmly bound to this by means of suitable adhesives. Then the profiles 32 are coupled to the metal profiles 2, the former being already coupled with the corresponding wooden profiles 26. This operation, which is carried out through mechanical forcing with a press or with a suitable rolling equipment, foresees that the wings 42 of each profile 32 engages with the inner wings 18,20 and the outer wings 14,16 of the corresponding metal profile 2.
More precisely during this forced insertion the
triangular rib 22 of each external wing 14,16 of the metal profile 2 slides along the external surface of the corresponding inclined wing 42 of the profile 32 which elastically bends until this triangular rib 22 snap engages with the groove 46 of the wing 42, thus firmly binding the metal profile 2 to the plastics profile 32. This snap engagement can be obtained due to the mutual arrangement between the rib 22 and the corresponding groove 46, with a slight elastic yielding of the rib 22 and this allows to use for the construction of the profile 32 a plastic material sufficiently loaded and therefore sufficiently stiff and such as to ensure the maintenance of the obtained snap engagement. The contrast between the edge of the wings 42 and the outer surface of the wings 18,20 of the profile 2 also cooperates to the steadiness of this engagement.
It iε also foreseen that the coupling between the two profiles 32 and 2 is make easier by the smooth shape of the relevant inner wings 44 and 18,20.
The so obtained composite profile combines the advantages of a high thermal insulation between the outer metal element and the inner wooden element, with the advantages of a complete non deformabilit , due to the possibility of mutual longitudinal sliding between the
several parts, and therefore an absorption of the unavoidable changes of thermal dilation due the different kind of the composing materials. The sliding between the wood and the plastics, practically eliminable when using a loaded plastics having a dilation coefficent near to that of the wood, is however allowed by the same elasticity of the used adhesive and by the surfaces into touch; the sliding between the plastics and the metal is allowed by the same mutual engagement. In order to realize a frame assembly, for example a leaf door, the composite profiles are cut according to the sizes of the fixed frame and of the door and then are assembled according to traditional technique to form the two different f ames. Then the external gasket 10, the double grazing unit 12 and the glass-block profile 58 already provided with a gasket 60, the gasket 34 and the accessories are applied to the frame of the door.
Subsequently the frame which forms the fixed frame iε fixed to the pallet already applied to the masonry 38 and the door is then applied to the fixed frame.
Substantially in the compoεite profile according to the invention, the converging arrangement of the wings 42 of the
plastics profile 32 on one hand makes easier the snap engagement between this and the metal profile 2 and on the other hand, due to the elastic reaction of the deformation, to which the wings are subjected in engagement condition oppose to their disengagement during the use of the assembly frame and at the same time they take their mutual position, thus ensuring the parallelism between the visible surface of the metal and of the wood.
In such a way the drawbacks of the prior art are avoided, in which the function for contrasting the disengagement is carried out by elements different from those which cerry out the functions of stabilization and which can be plastically and not elastically deformed during .the coupling stage, not ensuring the parallelism between the visible surfaces of the wood and of the metal. ~-
In the embodiment shown in fig. 2, each internal wing of the plasticε profile iε connected to the external wing, εo as to form a tubular appendix 64 ensuring a εteady εnap engagement between the plaεticε profile and the metal profile alεo without the preεence in this latter of the inner profile. In this case the pre-loaded condition of the external converging ribs of the plastics profile 32 is obtained through the elaεtic reaction of the deformed tubular
appendiceε 64.
The same result can practically be obtained with the embodiment shown in fig. 3 in which the plastics profile 32 presents only one tubular appendix 66, formed by the two external converging wings connected each other to. The embodiment shown in fig. 4 εubstantially coresponds to the embodiment of fig. 3 but it differs from thiε latter for the different εhape of the two tubular appendiceε 64, which cooperate with a central rib 68 foreεeen in the metal profile 2 to give a more effective transverεal εteadineεε to the two elementε and to enεure their centering during the aεεembly εtage.
This steadiness can further be increased with the embodiments shown in figs. 5 and 6 in which also the metal profile 2 is provided with two ribs 18, similar to those of the plaεtics profile 2 of fig. 1, separated or connected each other to. The compoεite profile εhown in fig. 7, uεed for the construction of the fixed frame of the asεembly frame, differes from the corresponding profile of fig. l since the sealing gaεket 50, inεtead of engaging with the groove 48 foreεeen in the metal profile 2 of the fixed frame and adhering, when the aεsembly frame is closed, to the metal profile 2 of the door, engages with a groove 48' foreseen
partly in the metal profile 2 and partly in the plasticε profile 32 which form the door and adhereε, when the assembly frame is closed, to the plasticε profile 32 which form the fixed frame. In this way the longitudinal chamber 52' which is formed by the door and the fixed frame, is completely limited by the thermoinsulating plasticε material and this preventε from the arising of condensation phoenomena of the air housed therein, such phoenomena being well evident in the case the longitudinal chamber adheres to the metal profiles. Consequently the wooden profile 26 which faces this longitudinal chamber 52' and all the accesoorieε which generally are housed within it are kept apart from the dangerous effects of the humidity.