The present invention relates to a method of forming a door assembly.
Background of the Invention
Door assemblies have been produced for many years. Compression molded door assembles are often superior to a wooden door, in that they have dimensional stability which resists excessive deflection and warping caused by temperature and humidity differentials. For example, in prior US patent 4,965,030 a compression molded door assembly has been disclosed having compression-molded skins and compression molded panel. The panel may be molded with one of the skins or molded separately. The surfaces of the panel and a surface of each of the skins have a textured pattern, which simulates the grain and texture of a wood door. A core is positioned between said skins. The construction of the skins permits effective introduction of foam to form the core therebetween following assembly of the skins.
Similarly in US 5,537,789 a door assembly is disclosed having a core positioned within a frame. The door assembly further includes a pair of opposed molded skins. There are edges adjacent the skins. The skins are made of a polymer material, a low profile additive and reinforcement fibers. Each of the skins has an exterior surface and an interior surface. The interior surface is adjacent the core. The exterior surface includes a textured pattern consisting of level portions and depressions.
In US publication 20030005645 a fireproof door assembly structure is disclosed comprising two molded door panels of compression molded thin skins overlaid with each other to form door with a hollow core. A rectangular foamed sealing is provided on said door panels operable to said frame of the opposing panel when said panels are overlaid with one another; a reinforcing part located respectively between said panels in the area where the handle will

be attached with said door panels; and a fireproof material core formed in place between said door panels to produce a real wood like fireproof door.
US patents 4,922,674; 4,901,493; 4,152,876; 4,860,512 etc. are other examples of prior patented compression molded door assemblies.
In the existing technology the two skins are held onto a frame and through a hole in the frame the core material, which is a polyurethane foam, is injected to a required volume and held in position till curing takes place. The whole assembly then becomes integral.
The main disadvantage of this method is the possibility of unfilled areas in the chamber between the skins, which could result in a hollow space, pores or soft spot, which makes the assembly weak, incapable of solid bonding and susceptive to breakage of skin under impact. As all dispensing equipment operates on tolerance on shot volume there is a possibility of such occurrence from piece to piece. Also, the existing method requires projections to be present in the inner surfaces of the skins and matching profiles to be cut in the frames for better locations of the skins with the frame.
Object of the Invention
The primary object of the present invention is to provide a compression molded door assembly that is both attractive and also has strength and dimensional stability. A further object of the invention is to provide a door assembly, which can utilize a number of different central panel configurations.
Other objectives and advantages will become apparent from the description and drawings

Summary of the present invention
The present invention overcomes the drawbacks of the existing technology by providing a novel method of manufacturing a compression molded door assembly. In this method, a door assembly having top, bottom and a pair of opposed side edges and having (a) skin members joined to form a chamber consisting of a pair of spaced apart longitudinal (stiles) one adjacent each of said side edges (rails) and (b) molded foam core in said chamber molded according to the inner profile of the skins to fit in the chamber molded according to the inner profile of the skins to fit in the chamber exactly to the inner dimension of the chamber. The door assembly has compression molded skins with one or more central panels with a suitable outer frame are provided. The outer surfaces of the skins have a textured pattern, which simulates the grain and texture of wood door. A core made out of molded foam material to exact inner profile of the door skins is positioned between the said skins. The profile of the door skins is positioned between the said skins. The construction of the skins permits effective introduction of the molded foam to form the core therebetween following assembly of the skins.
The present invention ensures that there are no unfilled areas in-between the skins and the outer frame thereby resulting in a high quality door assembly with uniform density.
Brief Description of the drawings
The invention is described in details in an unrestricted manner with reference to a particular embodiment thereof illustrated in the accompanying drawings, in which:

Figure 1 is an elevational view of the compressed molded door assembly (4 panels) according to the present invention;
Figure 2 is an exploded filamentary view of compression molded door assembly (4 panels) according to the present invention;
Figure 3 is a fragmentary view of the frame assembly;
Figure 4 is a fragmentary view of the compression molded skin sections (4 panels).
Detailed Description of the Invention
Figures 1 and 2 according to the present invention shows the elevational and exploded view of the door assembly respectively. The door assembly according to the present invention comprises a top compression molded SMC skin (1), a bottom molded compression molded SMC skin (2) and a frame assembly (4). One or more central panels (3) are provided on the surfaces of the top and bottom compression molded SMC skins (1, 2). Pre-molded expanded polystyrene (EPS) is denoted by numeral (5).
According to the inventive method, the pre-molded foam/expanded polystyrene (5) is made out to the exact inner profile of the door skins (1, 2) and is positioned between the said skins (1, 2). Using a molded foam core is unique to this invention as the foam core is separately molded to form a component, which would have the exact profile of the inner side of the molded SMC skins. This fits in exactly in the chamber formed as the doorframe between the stiles and the rails (6 and 7 of figure 3). There would be absolutely no gaps between the skins (1,2) and the core (5) and the bonding is perfect to

make a solid door assembly. Also, since there is perfect alignment with the frame (4), there is no requirement of locators as in the prior art.
Figure 3 shows the fragmentary view of the frame assembly (4). The stiles (6) and the rails (7) are made out of Wood PVC or other suitable material. Numeral (8) refers to a lumber block for door lock. The frame assembly (4) is further provided with stiffeners (9, 10) made out of Laminated Veneered Lumber (LVL).
Figure 4 is a fragmentary view of the compression molded skin sections. Detail D gives the design of the profile of the panels; section C-C gives the details of the construction of the door assembly. The top and bottom SMC molded skins are denoted by numerals (11, 12). The wood PVC stiles are denoted by numeral (6) and the LVL stiffeners are denoted by numeral (9). Numeral (15) denotes the lumber block for the lock and the EPS is denoted by numeral (5). Section A-A gives details of the panel profile and section B-B gives another view of the door profile.

We Claim:
1. A method of forming a compressed door assembly having top, bottom
and pair of opposed side edges comprising the steps of:
Providing at least two sheet molded compound (SMC) skins with one or more central panels with a suitable outer frame;
Providing a pre-molded foam core having the exact profile of the inner side of the molded SMC skins, said pre-molded foam core being fitted exactly in a chamber formed by stiles and rails according to the inner dimensions of the chamber;
Compressing the skins and the pre-molded foam core to form the compressed door assembly.
2. The method as claimed in claim 1, wherein the outer surface of the SMC skins have a textured pattern which simulate the grain and texture of wood door.
3. The method as claimed in claim 1, wherein the pre-molded foam core is an expanded polystyrene (EPS).
4. The method as claimed in claim 1, wherein the stiles and rails are
formed from wood PVC and Laminated Veneered Lumber (LVL).
5. A compressed door assembly formed by the method as claimed in the
preceding claims.