(under the class definition) A collection of documents comprising spring devices that have variable or adjustable support characteristics, with the support characteristics of the spring changeable from one fixed value to another fixed value.
SEE OR SEARCH THIS CLASS, SUBCLASS:
697, for mattresses with uniform firmness that is changeable by the user.
716+, for mattresses having innerspring-type cores.
SEE OR SEARCH CLASS
267, Spring Devices,
177, for coil springs including an adjustable end thrust member to vary the thrust reaction.
