A spring package, with grooves to hold the spring washers at the inner and outer edges, reduces hysteresis to a minimum. Three-segment retainers permit easy disassembly so that the spring rate can be changed

Mac Glashan, W. F.

English

NASA Technical Reports Server

Spring Depresses to Absorb Energ 
4
Three -Seg ii 
Outer Retainer 
--
 nnr.FWWW No 
Inner slian
Conical Spri
Washers 
Outer Tube 
March 1964
NASA TECH BRIEF
Brief 63-10247 
This NASA Tech Brief is issued by the Technology Utilization Division to acquaint industry 
with the technical content of an innovation derived from the NASA space program. 
New Package for Belleville Spring Permits Rate Change, Easy Disassembly 
The problem: To effect basic improvements to the 
Belleville spring package so that the spring washers 
can be added or taken out to vary the spring rate and 
still provide non-linear characteristics. Standard de-
signs have undesirable hysteresis effects and present 
problems in inserting or removing washers. 
The solution: A new kind of spring package that 
has grooves to hold the spring washers at both the 
inner and the outer edges. Hysteresis, or lag effects are 
reduced to a minimum. Three-segment retainers per-
mit easy disassembly so that the spring rate can be 
changed. 
How it's done: Key elements of the improved 
spring package are the grooved, three-segment, inner 
-	 and outer retainers. The segmented retainer permits
the spring package to be quickly assembled or dis-
assembled. The inner edge of each conical spring 
washer is held in a groove of the inner segmented 
retainer. A shaft fits into the central axis of the re-
tainer to hold it in place. 
Outer edges of the conical springs are held by 
grooves in the outer retainer, also made in three seg-
ments for easy disassembly. Segments are held in place 
by the outside tube which surrounds the outer retainer. 
In standard designs the outer radius of the last 
spring washer and the inner radius of the first spring 
carry the entire load. Forces are concentrated at the 
periphery of the washer, resulting in plastic deforma-
tion and large hysteresis effects.
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and S pace Administration. Neither the United States Govern-
ment, nor NASA, nor any person acting on behalf of NASA: A. Makes 
any warranty or representation, express or implied, with respect to the 
accuracy, completeness, or usefulness of the information contained in
this document, or that the use of any information, apparatus, method, 
or process disclosed in this document may not infringe privately-owned 
rights; or B. Assumes any liabilities with respect to the use of, or for 
dama g es resulting from the use of, any information, apparatus, method, 
or process disclosed in this document.
https://ntrs.nasa.gov/search.jsp?R=19630000034 2020-03-11T16:46:12+00:00Z
Since both inner and outer edges of the spring 
washers in this innovation are held by the grooves of 
the two retainers, each spring flexes the same amount 
and carries the same proportion of the load. Spring 
washers can easily be removed or added to effect a 
change in the spring rate or spring characteristics. 
The spring package is disassembled by first removing 
the outer tube and taking out the outer grooved re-
tainer, then the center shaft, and finally the inner 
retainers. 
Notes: 
1. Although this innovation was designed as a high-
pressure regulator in a space vehicle, it would have 
value in any machine where space is limited or 
where the required helical spring would have a
small index (ratio of coil spring diameter to the 
diameter of the wire). 
2. Other uses of this device could be the popoff valve 
of a boiler. Action of the spring results in extremely 
high tension with very slight movement. 
Patent status: NASA encourages the immediate 
commercial use of this invention. It is owned by 
NASA and a patent application has been filed. When 
patented, royalty free, non-exclusive licenses for its 
commercial use will be available. Inquiries concerning 
license rights should be made to NASA Headquarters, 
Washington, D.C., 20546. 
Source: William F. MacGlashan 
Jet Propulsion Laboratory (J PL-392) 
Brief 63-10247


New package for Belleville spring permits rate change, easy disassembly

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server