STATEMENT OF THE INVENTION :
This invention pertains to the method and process of joining / assembly of the Sandwich Panels by welding the internal and external (or one of the) joints between the sandwich panels without de-lamination (failure of the adhesive bond due to weld heat) of the metal facings from the core, to form enclosures or structures.
PRIOR ART;
Previously the Sandwich panels were assembled to form enclosures or structures by using rivets or fasteners as illustrated in Fig 1. This involved internal and external angles to assemble the sandwich panels with rivets.
DRAWBACKS IN PRIOR ART :
The assembly of the sandwich panels using rivets resulted in thousands of potential leakage points for the leakage of rain water, dust ingress, penetration of external environment effects like humidity, temperature, RF radiation, nuclear radiation etc. The enclosure or structure thus constructed exhibited lesser structural and performance characteristics and was prone to degradation in performance due to loosening of rivets / fasteners due to Transit and environmental effects etc over periods of time in usage.

SOLUTION TO DRAWBACK:
The technology of assembling the sandwich panels by welding the internal and external (or one of the) joints between the sandwich panels results in the elimination of rivets / fasteners in assembly of such enclosures / structures , thus resulting in a hermetically sealed enclosure / structure exhibiting superior levels of water sealing, dust sealing and structural strength. Also, since the weld joints have lower impedance than a riveted joint in a sandwich paneled composite structures or enclosures, as a result welded assembly of structural sandwiched paneled enclosure / container exhibit high levels of RF shielding. The welded joints are not prone to transit or environmental degradations.
SUMMARY OF THE INVENTION :
Sandwich panels are useful structural components providing increased strength and stiffness despite their minimal weight. The sandwich panels are useful in many applications like enclosures, containers, structures, etc. These panels are assembled to form required enclosures or structures. This invention pertains to the technology of assembly of the sandwich panels by welding the internal and external (or one of the) joints between the sandwich panels as illustrated in fig 2 without de-lamination (failure of the adhesive bond due to weld heat) of the metal facings from the core. The assembled panels may be either at 90 deg to each other or at any other angle. The weld bead may also run at any place other then the edges of the panel ( for eg: Welding at the center of the panel to another sandwich panel forming a T-Joint).
2

DETAILED DESCRIPTION OF THE INVENTION :
A Sandwich Panel is fabricated by adhesively bonding of thin (0.8 mm to 5 mm) metal facings to either side of a core material using adhesives. The various facings which can be employed in the fabrication of the sandwich panels are as listed but not limited to: Aluminum sheet, steel sheet, galvanized Iron sheet and sheets of other metals. The various core materials which can be employed in the fabrication of the sandwich panels are as listed but not limited to: Rigid polyurethane foam cores, Honey comb cores (metallic as well as non-metallic), plywoods, woods etc. These sandwich panels are assembled to form enclosures or structures for various applications.
The sandwich panels are fabricated individually by employing any of the combinations of facings and core materials using adhesives, incorporating the facility for weld ability of the panels. Welding is carried out to join the sandwich panels together to form the enclosure or structures.
The sandwich panels can be assembled by welding to form hermetically sealed and or EMI shielded enclosures/ cabins / structures/marine structures / offshore installations / mobile and static systems, etc.
BRIEF DESCRIPTION OF THE DRAWINGS ;
The preferred embodiment of the present invention is described in conjunction with the associated drawings in which like features are indicated with like reference numbers and in which
3

Fig.l is an external and internal views of the assembly of sandwich panels by
riveting.
Fig.2 is an external and internal views of the assembly of sandwich panels by
welding.
While the preferred embodiments of the invention have been illustrated and
described, it will be clear that the invention is not limited to these embodiments
only. Numerous modifications, changes, variations, substitutions and equivalents
will be apparent to those skilled in the art without departing from the spirit and
scope of the invention as described in the claims.

1. the fabrication of sandwich panels having metal facings and core of metal / non-metallic materials, adhesively bonded together so as to permit joining with other sandwich panels by welding the joints without de-lamination (failure of the adhesive bond due to weld heat) of the metal facings from the core.
2. the fabrication of sandwich panels having metal facings and core of metal / non-metallic materials, adhesively bonded together so as to permit joining with other metallic components or parts by welding without de-lamination (failure of the adhesive bond due to weld heat) of the metal facings from the core as claimed in claim 1 which renders hermetical sealing to the joints thus suitable for its use in applications like blast pressure resistant/ ballistic enclosures (mobile/static),RF shielded enclosures (mobile/static)communication centers(mobile/static) and structures[mobile/static].