Dual-spring plunger for a plunger matrix mattress

U.S. Patent 9,119,478

Issued September 1, 2015

Abstract

A dual-spring plunger for a plunger matrix mattress assembly includes an outer tension spring with an upper end fixed to an outer spring mount of a plunger guide body and a lower end located below the guide body positioned to receive a bottom end of a pin of the plunger. An inner tension spring nested within the outer tension spring has an upper end fixed to the inner spring mount of the guide body and a lower end having a spur slidably captured within a slot through a fin of the shaft of the pin. 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, whereas both the outer and the inner spring are tensioned during a second portion of downward movement of the pin relative to the pin guide.