Reinforced plastic panel

Claim 2

A reinforced plastic member comprising a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, the margins of said sheets being joined together to form an interior cavity, structural inserts having terminations in said cavity encapsulated by said sheets, said inserts being reinforcing beam constructions of rigid material, and compressible means for separating the sheets from the rigid material to establish relative movement of the sheets with respect to the rigid material at said insert terminations thereby avoiding internal stresses in said sheets due to differential changes in dimensions of the plastic material of the sheets and the rigid material of the inserts upon changes in temperature.

Claim 3

A reinforced plastic panel comprising a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, the margins of said sheets being joined together to form an interior cavity, structural inserts in said cavity encapsulated by said sheets, said inserts being reinforcing beam constructions of rigid material, a compressible sheath surrounding said beam constructions, said sheath being sandwiched between the encapsulating material and the rigid material of the beams thereby avoiding internal stresses in said sheets due to differential changes in dimension of the plastic material of the sheets and the rigid material of the inserts upon changes in temperature.

Claim 4

A reinforced plastic panel comprising a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, the margins of said sheets being joined together to form an interior cavity, structural inserts in said cavity encapsulated by said sheets, said inserts being reinforcing beam constructions of rigid material, a compressible sheath surrounding said beam constructions, said sheath being sandwiched between the encapsulating material and the rigid material of the beams thereby avoiding internal stresses in said sheets due to differential changes in dimension of the plastic material of the sheets and the rigid material of the inserts upon changes in temperature.

Claim 5

The combination as set forth in claim 2, wherein: said reinforcing beams are arranged about the periphery of said sheets, said beams having their registering ends intersecting each other, the rigid material of one beam on one margin portion of said sheets being received within the adjacent rigid beam on an adjacent margin of said sheets, whereby said rigid beams may shift one with respect to the other due to shrinkage of said plastic material upon changes in temperature.

Claim 6

The combination as set forth in claim 3, wherein: said beams include also an intermediate beam bridging intermediate portions of two opposed peripheral beams, thereby increasing the rigidity of the panel at the intermediate load supporting surface.

Claim 7

A reinforced plastic panel comprising, a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, the margins of said sheets being joined together to form an interior cavity, structural inserts in said cavity encapsulated by said sheets, said inserts being reinforcing beam constructions of rigid material, a compressible sheath surrounding said beam constructions, said sheath being sandwiched between the encapsulating material and the rigid material of the beams thereby avoiding internal stresses in said sheets due to differential changes in dimension of the plastic material of the sheets and the rigid material of the inserts upon changes in temperature, said reinforcing beams being arranged about the periphery of said sheets, said beams having their registering ends intersecting each other, the rigid material of one beam on one margin portion of said sheets being received within the adjacent rigid beam on an adjacent margin of said sheets, whereby said rigid beams may shift one with respect to the other due to shrinkage of said plastic material of the sheets upon changes in temperature, said beams including also an intermediate beam bridging intermediate portions of two opposed peripheral beams, thereby increasing the rigidity of the panel at the intermediate load supporting surface, the ends of said intermediate beam intersecting the intermediate portions of said opposed beams, said opposed beams being formed with apertures that receive the ends of said intermediate beam, the ends of the latter overlapping intermediate portions of the opposed beams whereby relative shifting movement therebetween is accommodated upon changes in dimension of said plastic material due to changes in temperature.

Claim 8

A reinforced plastic panel comprising, a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, the margins of said sheets being joined together to form an interior cavity, structural inserts in said cavity encapsulated by said sheets, said inserts being reinforcing beam constructions of rigid material, a compressible sheath surrounding said beam constructions, said sheath being sandwiched between the encapsulating material and the rigid material of the beams thereby avoiding internal stresses in said sheets due to differential changes in dimension of the plastic material of the sheets and the rigid material of the inserts upon changes in temperature, said reinforcing beams being arranged about the periphery of said sheets, said beams having their registering ends intersecting each other, the rigid material of one beam on one margin portion of said sheets being received within the adjacent rigid beam on an adjacent margin of said sheets, whereby said rigid beams may shift one with respect to the other due to shrinkage of said plastic material of the sheets upon changes in temperature, said beams including also an intermediate beam bridging intermediate portions of two opposed peripheral beams, thereby increasing the rigidity of the panel at the intermediate load supporting surface, the ends of said intermediate beam intersecting the intermediate portions of said opposed beams, said opposed beams being formed with apertures that receive the ends of said intermediate beam, the ends of the latter overlapping intermediate portions of the opposed beams whereby relative shifting movement therebetween is accommodated upon changes in dimension of said plastic material due to changes in temperature.

Claim 9

The combination as set forth in claim 1, wherein: said inserts form an internal corner and one of said sheets is separated from said reinforcing member in the region of said corner.

Claim 10

The combination set forth in claim 1 wherein said reinforcing member includes one or more recesses defining cavities extending in a predetermined characteristic direction, one of said sheets is separated from said reinforcing member in the region of said recesses, thereby avoiding internal stresses in said thermoplastic material.

Claim 11

A reinforced plastic panel comprising a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, portions of said sheets being joined together to form an internal cavity, structural inserts in said cavity encapsulated by said sheets, said inserts being formed of rigid material, a compressible member located between at least one of said sheets and said rigid material, said compressible member being sandwiched between the encapsulating material and the rigid material, thereby avoiding internal stresses in said sheets due to differential changes in dimensions of the plastic material of the sheets and the rigid material of the inserts upon chAnges in temperature.

Claim 12

A reinforced plastic panel comprising a pair of formed thermoplastic sheets situated in juxtaposed registering relationship, portions of said sheets being joined together to form an internal cavity, structural inserts in said cavity encapsulated by said sheets, said inserts being formed of rigid material, a compressible member located between at least one of said sheets and said rigid material, said compressible member being sandwiched between the encapsulating material and the rigid material, thereby avoiding internal stresses in said sheets due to differential changes in dimensions of the plastic material of the sheets and the rigid material of the inserts upon chAnges in temperature.