Crest-to-crest compression spring with circular flat shim ends

A crest-to-crest circular, resilient, compression spring having load support surfaces for supporting a work element thereon disposed at opposite ends of said spring the spring being formed from an elongate flat wire strip spirally wound around a common edge of the wire strip and around the longitudinal axis of the spring to form a series of spring turns, the compression spring having two free ends at opposite end portions of said spring, each of the spring turns lying adjacent to each other so as to form a multiturn ring, each of said spring turns having a plurality of successive waves therein, each of said waves including separate wave crest and wave trough portions, said waves defining a wavepath between the opposite free ends of said spring, the amplitude of the waves in said wavepath incrementally diminishing from a preselected wave amplitude present in the central portions of the spring down to a zero wave amplitude at the opposite ends of said spring, said spring including three continuous and distinct wave regions, the first distinct wave regions being generally disposed in the central portion of the spring, said first distinct wave region including at least one spring turn, the second distinct wave region including two second wave region portions disposed generally adjacent to and outwardly of said first distinct wave region, the two second distinct wave region portions each having a free height and each including one spring turn, and the third distinct wave region including two third distinct wave region portions disposed generally adjacent to and outwardly of said two second wave region portions, the amplitude of the waves in each of said second distinct wave region portions incrementally diminishing down from said first wave region preselected wave amplitude uniformly within said second wave region to a zero wave amplitude in said third wave region, said third wave region beginning where said second wave region wave amplitude reaches said zero wave amplitude, the opposite ends of said spring each including portions of a spring turn which have a constant zero wave amplitude, said third wave region portions forming two load support surfaces which are substantially perpendicular to the longitudinal axis of said compression spring and are substantially parallel to each other, each of said two load support surfaces having a substantially uniform thickness.

A crest-to-crest circular, resilient, compression spring having load support surfaces for supporting a work element thereon disposed at opposite ends of said spring, the ring being formed from an elongate flat wire strip spirally wound around a common edge of the wire strip and around the longitudinal axis of the spring to form a series of spring turns, the compression spring having two free ends at opposite end portions of said spring, each of the spring turns lying adjacent to each other so as to form a multiturn ring, each of said spring turns having a plurality of successive waves therein, each of said waves including separate wave crest and wave trough portions, said waves defining a wavepath between the opposite free ends of said spring, the amplitude of the waves in said wavepath incrementally diminishing from a preselected wave amplitude present in the central portions of the spring down to a zero wave amplitude at the opposite ends of said spring, said spring including three continuous and distinct wave regions, the first distinct wave region including at least one spring turn and being disposed generally in the central portion of the spring, the waves of said first distinct wave region having a constant amplitude, the second distinct wave region including two second wave region portions disposed generally adjacent to and outwardly of said first distinct wave region, the two second distinct wave region portions each having a free height and the waves of each of said second distinct wave region portions having a variable amplitude and each second distinct wave region portion including one spring turn, and a third distinct wave region including two third distinct wave regions portions disposed generally adjacent to and outwardly of said two second wave region portions, each of said third distinct wave region portions including a single wave of constant zero amplitude, the amplitude of each of said second distinct wave portions incrementally diminishing down in a uniform manner from said constant wave amplitude of the first wave region to the constant zero wave amplitude in the third wave region, the amplitude of successive wave crest and wave trough portions in each of said two second distinct wave region portions being incrementally diminished in said uniform manner by an incremental reduction factor of I derived from the formula:

• ##EQU5## wherein:
• A=The amplitude of the first distinct wave region (in.).
• N=The number of wave crests and trough portions per spring turn found in the second wave region portion,
• said third wave regions beginning where said second wave region portions reach a zero wave amplitude, each of said third distinct wave region portions of constant zero wave amplitude including a spring turn which extends between 300.degree. and 540.degree. of revolution around said spring longitudinal axis, said third distinct wave region portions thereby forming two compression spring load support surfaces which are substantially perpendicular to the longitudinal axis of said compression spring and which are substantially parallel to each other, each of said load support surfaces having a substantially equal and uniform thickness.