Hinged inner spring mattress and manufacturing method

A hinged inner spring mattress and support therefor comprising:

• a chest for supporting the mattress, the chest having an access panel on one end therefor;
• a pair of base sections positioned on the chest with one base section extending over the chest access panel, each base section having an inner spring and padding framework with top and bottom surfaces and peripheral side wall, the peripheral side walls of the base sections including corresponding hingeable side walls;
• a pair of shell portions enclosing the bottom surfaces and side walls of the base sections, each shell portion having a hinge forming sheet of substantially nonstretchable fabric extending across the bottom surface and upwardly along the hingeable side wall of a respective base section, the hinge forming sheets being joined together along a hinge axis adjacent the top surfaces of the base sections, whereby one base section may be rotated about the hinge axis relative to the other base section from a normal position, wherein the top surfaces are coplanar, to a retracted position to uncover the access panel;
• and
• a hinge line cover sheet of substantially nonstretchable fabric extending along the top surfaces of the base sections and over the hinge axis with free ends extending on each side of the hinge axis, the cover sheet being secured at its free ends to the top surface of each base section in a parallel manner to the hinge axis with a central segment of the hinge line cover sheet in tension so that this central segment of the cover sheet which extends over the hinge axis is placed in tension when the base sections are coplanar.