"SECTION OF WOOD SUBSTITUTE WHICH CAN BE USED IN PARTICULAR TO FORM THE FRAME PARTS OF FURNITURE DOORS"
This invention relates to a section obtained from a wood substitute substance which is in itself known such as "chipboard" or better "MDF" which is particularly- usable in the furniture industry, especially for making door frames, permitting the development of a new operating procedure which is appreciably simpler, more rational and more ' economical than those currently in use. As is known, particularly in the abovementioned furniture industry, natural wood species are being progressively replaced in practice by substitutes such as agglomerates based on wood chips or wood sawdust of various particle sizes. Using various techniques and procedures, all of which are well known, with such agglomerates, particularly those forming the so-called "chipboards", panels of various sizes and thicknesses are normally produced as well as rarely, in certain circumstances, individual elements which are shaped to form parts of corresponding pieces of furniture. Especially with very fine grained and homogeneous agglomerates such as MDF and the like, various elements having various shapes are produced using techniques and procedures which are all known, the so-called "semifinished products" which are in practice applied to parts of furniture or even members forming components of the furniture itself. A process of this type which has been known for some time and which is now in ordinary use is that commonly known by the term of "membrane pressing" . According to this system, starting from suitable uanels of a suitable ligneous agglomerate (normally MDF) which has already been coated (finished) on one side with - suitably coloured and/or decorated paper impregnated with a suitable substance such as normally a melamine resin, initial substantially rectangular members, in practice longitudinal members having a rectangular cross-section of specified length, width and thickness, are first obtained throxigh
suitable mechanical machining. Further mechanical machining carried out using suitable machines such as mills, routers, lathes, etc., the said initial members are given the final desired shape. Groups of members shaped in this way are then placed on the supporting surface of a special press, and then covered with a sheet of PVC of thickness between 0.25 mm and 0.5 mm or other suitable coating material and are finally hot compressed by a layer of suitable elastomer applied to the pressurising plate of the press used with the result that they are wholly coated. The individual members coated in this way are then cut and detached by essentially manual operations from the single sheet of coating material used for that operation and are finally blocked out and trimmed again using manual or mechanical operations .
The abovementioned process is currently used in virtually all the various sectors of the furniture industry, and is particularly and extensively used especially in the specific sector of the manufacture of doors, especially doors formed of a panel surrounded by a frame in which it is essentially used to produce the individual components of the said frame and specifically the two vertical members located at the sides of the door commonly referred to as "stiles", and the horizontal members located transversely at the top and bottom of the door respectively, and at intermediate locations between these, commonly referred to as rails.
Although this process is the fruit of recent progress, refinements and improvements in production techniques, it is clearly as a whole rather complex, as a result of which, in order to improve and further simplify the system for production of the frames for this type of door, a new process has been developed which according to this invention provides for the formation of a section from which members of the required length can
be easily and rapidly obtained and used in forming the frame of a door instead of stiles or rails produced using the abovementioned "membrane press" process. In order that the characteristics, the various possible advantages in application, the appreciable simplification in manufacture and the consequent economic advantages which use of the section in question makes possible, it is all described in detail below purely by way of the non-restrictive example with reference to the appended drawings in which:
- Figure 1 shows a front view of a door with a frame in which the lateral stiles which are cut off at right angles at their ends are connected to corresponding flat parts produced at the ends of the inner sides of the corresponding top and bottom transverse members,
- Figure 2 is a view in cross-section along the line I- I in Figure 1,
- Figure 3 is a view in cross-section along the line II-II in Figure 1,
- Figure 4 is a front view of a door wholly similar to that illustrated in Figure 1 and differing from that only in that in the frame the lateral stiles extend over the full height of the door and the top and bottom transverse members are connected to corresponding flat parts at the ends of the inner sides of those lateral stiles,
- Figure 5 is a view in cross-section along the line III-III in Figure 4,
- Figure 6 is a view in cross-section along the line IV-IV in Figure 4,
- Figure 7 illustrates in a magnified view details of the connection between stiles and rails identified by X
in Figures 3 and 5, the two short lengths of the corresponding members forming a stile and corresponding rail of a frame of a door arranged separately from each other prior to connection and in which a first member obtained by the known "membrane press" process has a greater thickness' than that of a second member comprising a length of the section in question,
- Figure 8 shows the same members in Figure 7 connected together,
- Figure 9 shows as in Figure 7 a short length of a first member obtained using the "membrane press" process and a short length of a second member comprising a length of the section in question in which the first and second member have equal thicknesses, arranged separately from each other prior to connection,
Figure 10 shows the same ' members in Figure 9 connected together,
- Figure 11 shows centrally an exploded perspective view of the various components of the entire door of the type illustrated in Figures 1, 2 and 3, and on the left in perspective view a length of a generic section constituting the object of the invention and which is used in that figure to form the stiles of the corresponding door and finally on the right an exploded perspective view of the detail of the application of a suitably shaped plate to the end of a stile as provided in the embodiment illustrated in Figures 9 and 10.
In the figures mentioned above common features are identified using the same reference numbers. Firstly it will be clearly seen from Figure 11 that the fundamental object of this invention essentially comprises a simple and very normal section which although wholly obvious and known in its execution,
structure and shape makes it possible in its particular use and its specific application to put into effect a new production process in the specific field of application which brings about appreciable rationalisation and simplification of the operations and operational stages together with obvious corresponding economic advantages .
The composition and manufacturing process of said section 1 identified by reference P in Figure 11 will therefore be described summarily. Starting from a panel of wood conglomerate of the "finished" type such as a common "chipboard" or better a more suitable "MDF" of suitable thickness, strips of a desired width are cut from a suitable thickness in ways and using means which are known. The strips of rectangular cross-section with the rectangular cross-section so obtained are shaped into the final desired shape through further machining carried out on their uncoated ("unfinished") surfaces using suitable machines (mills - lathes - routers and/or others) and in practice their longitudinal edges are bevelled in various ways and a groove F is made along their side. The bodies shaped in this way are then pressed with a sheet normally comprising a suitable layer of PVC in a thickness of approximately 0.2-0.5 mm using procedures and means which are well known, yielding the section P in question whose use in accordance with this invention is described in detail below.
For simplicity and clarity of description reference is first made to only Figures 1, 2, 3 and 11. It will be seen from these figures that the generic door A essentially comprises in a wholly normal way a panel B surrounded by a frame formed by two lateral stiles M which are connected at their abutting ends to corresponding end portions at the extremities of the outer ends of corresponding rails T. As may be clearly seen in Figure 11, said panel B is engaged
perimeterally in groove F provided in both stiles M and rails T. With reference in particular again to Figure 11 it will be noted that all the ends of stiles M have fitted to them pegs S which are inserted into corresponding holes L provided in the corresponding parts of rails T in such a way as to bring about attachment between them following the provision of a suitable adhesive between the matching parts in question.
Everything which has been described above clearly merely describes the normal composition and the normal procedure for the manufacture of an ordinary door which can be used for a great variety of applications.
As described at the outset, at the present time the various components of a door frame for furniture are all obtained using the so-called "membrane press", a process which as already mentioned is on the whole rather complex and cumbersome. Use of the abovementioned section P in the way which is described below makes it possible to produce at least one part of the components of the frame of door A in a simple and economical way, specifically the two lateral stiles M of a first possible embodiment illustrated in Figures 1, 2, 3 and 11 already mentioned or the two transverse members (rails) T of a second possible embodiment which is instead illustrated in Figures 4, 5 and 6. Clearly in the first case rails T and in the second case stiles M identified for clarity by references 12° and 12b respectively are still produced by the "membrane press" system.
In order to obtain stiles M in the first arrangement or rails T in the second arrangement it is sufficient to cut off section P with transverse cuts at right angles to obtain corresponding lengths 11a (first arrangement - Figures 1, 2, 3 and 11) or lib (second arrangement - Figures 4, 5 and 6) .
As may be clearly seen from Figure 11 in particular, suitable holes L coinciding with each other which are designed to receive suitable attachment pegs S are provided in the ends resulting at the ends of lengths 11a (stiles M in the first arrangement) and on the end lengths of the inner side of rails T which are opposite to them when assembled, thus providing one of the possible known forms of connection which can be used to join the two members in question (stile M - rail T) together. Obviously for final connection a suitable adhesive is applied to the entire area of the connection in ways and using means and techniques which are known.
At this point it should be pointed out that stiles M and rails T may have thicknesses which differ from each other or which are the same, and that all the corresponding longitudinal edges are normally bevelled to a greater or lesser extent or better rounded with larger or smaller radiuses of curvature.
It follows that situations which may give rise to disadvantages of various kinds may occur in the connection areas .
For clarity, as already mentioned, the details identified by X relating to two of the areas of connection between a stile M and a rail T are illustrated in Figures 3 and 5. In subsequent Figures 7, 8, 9 and 10 the two main situations which may occur in the said areas of connection between stiles M and rails T are illustrated in appreciably enlarged views of the aforesaid details X. It is also pointed out that in these Figures 7, 8, 9 and 10 the thickness of the plastics coating layer of the MDF bodies constituting the members involved in the connection is indicated with a line of appreciably greater thickness than that which would actually correspond to the enlargement for
greater clarity in interpretation. More specifically, Figures 7 and 8 illustrate the connection between two members of different thickness in which the member of greater thickness is that obtained by the usual "membrane press" process and that of lesser thickness is that formed from a length of the profile to which this invention relates and Figures 9 and 10 illustrate ■the connection between two members of the same thickness .
With reference first to Figures 7 and 8, there will be seen a first member El of the type obtained using the "membrane press" process which has a thickness Hl which is greater than the thickness H2 of a second member E2 comprising a length obtained from a section of the type in question. Said first member El also has a longitudinal edge which is taller than the side against which the head of second member E2 will abut, this being radiused with a connecting radius R so that that side produces a flat surface of height N which is equal to or greater than the thickness H2 of said second member E2. It follows that, as may be clearly seen in Figure 8, when that second member E2 (length of section P) is connected to said first member El, the surface area of its connecting head which is clearly completely hidden and therefore devoid of any coating because it results from the transverse cut of section P from which second member E2 was obtained will wholly abut against a corresponding flat surface in such a way that in this case no cracks and/or discontinuities between the surfaces of the two members El and E2 remain in the area of the connection.
When instead, as clearly illustrated in subsequent Figures 9 and 10, a first member E3 of the type using the "membrane press" process and a second member E4 comprising a length of the section of the type in question have a thickness Z which is the same and the said first member E3 has an upper edge D on the side
where connection is made to corresponding second member E4 which is discretely radiused (with a connecting radius of 0.3 mm to 3.5 mm), the flat end of said second member E4 will when resting against the connecting side of corresponding first member E3 leave part of its surface exposed with consequent unacceptable disadvantages.
In order therefore to avoid the formation of this exposed part and the disadvantages deriving therefrom it is possible to proceed in at least two ways .
A first way provides for adequately bevelling the edge and merely covering the part which remains exposed with a suitable thin film.
A second method, as may be seen in Figures 8 and 9 and even more clearly in the detail shown on the right hand part of Figure 11, instead provides for application of a plate (edge) 8 of small thickness and having a shape or better a perimeter identical to that of the transverse cross-section of the said section, that is of the end of second member E4, to the total surface of the end of the length of section P forming said second member E4. The upper edge C of said plate (edge) 8 may be suitably radiused with a radius which is the same as or different from that of upper edge D of aforesaid first member E3 for essentially aesthetic reasons. Clearly both the film which is applied in accordance with the first method and the plate (edge) 8 which is applied according to the said second method may be of the same colour or a different colour from that of the material coating the members which are connected together and obviously suitable adhesives will be used and applied for attaching these and for final attachment of the members in each connection.
From what has been stated it is obvious that the use of a simple section P according to this invention is easy,
quick and therefore appreciably more economical and therefore the use according to this invention of lengths of the said section P to form stiles or rails used in combination with corresponding rails or stiles obtained through the usual "membrane press" process to manufacture the frames of doors of furniture makes it possible to achieve an appreciable reduction in production costs and therefore appreciable corresponding economic advantages. Although it is understood that many variants may be applied particularly to the various possible systems and/or procedures for shaping and coating the section in question and to the systems and means for connecting the members forming the stiles and/or the rails of the frames of doors which can be implemented using the new process described above, these and other variants may however be provided without thereby going beyond the scope of what has been described and is claimed below and therefore beyond the scope of protection of this industrial invention.