Dual-spring plunger for a plunger matrix mattress

A mattress assembly, comprising:

• a frame;
• a plunger matrix supported by the frame comprising a plurality of plungers suspended by a plunger support platform wherein each plunger provides an independent point of support and the plunger matrix defines a support profile for a person lying on the mattress assembly;
• a top pad located above the plunger matrix and the coil springs;
• wherein each plunger comprises:
• a pin guide comprising a flange, a guide body extending from the flange, an outer spring mount extending from the guide body, and an inner spring mount extending from the guide body wherein the outer and inner spring mounts are disposed in an axially tiered relation,
• pin slidably received within the pin guide comprising a flange located above the flange of the pin guide, a shaft extending from the flange through the guide body, a fin along the shaft of the pin, and an elongate slot through the fin,
• an outer tension spring having an upper end fixed to the outer spring mount of the guide body and a lower end located below the guide body positioned to receive a bottom end of the pin shaft,
• an inner tension spring nested within the outer tension spring having an upper end fixed to the inner spring mount of the guide body and a lower end comprising a spur slidably captured within the slot through the fin of the shaft, and
• wherein the outer spring is tensioned while the inner spring is not tensioned during a first portion of downward movement of the pin relative to the pin guide, and wherein both the outer and the inner spring are tensioned during a second portion of downward movement of the pin relative to the pin guide.

A modular mattress assembly, comprising:

• a plurality of plunger matrix sections, each comprising a separate plunger matrix support platform, configured for side-to-side assembly;
• a foldable edge frame configured to snugly receive and house the plurality of plunger matrix sections in side-to-side relation, the edge frame defining a flange on an internal surface of the edge frame configured to support a plurality of the plurality of plunger matrix sections in side-to-side relation in a position allowing the plungers to move up and down within an internal space defined by the edge frame;
• a top pad configured to lay on top of the edge frame and the plurality of plunger matrix sections in side-to-side relation housed within the edge frame;
• a cover configured encapsulates the edge frame, the plunger matrix, and the top pad into a self-contained mattress unit;
• wherein each plunger comprises:
• a pin guide comprising a flange, a guide body extending from the flange, an outer spring mount extending from the guide body, and an inner spring mount extending from the guide body wherein the outer and inner spring mounts are disposed in an axially tiered relation,
• a pin slidably received within the pin guide comprising a flange located above the flange of the pin guide, a shaft extending from the flange through the guide body, a fin along the shaft of the pin, and an elongate slot through the fin,
• an outer tension spring having an upper end fixed to the outer spring mount of the guide body and a lower end located below the guide body positioned to receive a bottom end of the pin shaft,
• an inner tension spring nested within the outer tension spring having an upper end fixed to the inner spring mount of the guide body and a lower end comprising a spur slidably captured within the slot through the fin of the shaft, and
• wherein the outer spring is tensioned while the inner spring is not tensioned during a first portion of downward movement of the pin relative to the pin guide, and wherein both the outer and the inner spring are tensioned during a second portion of downward movement of the pin relative to the pin guide.