Wales Hydra News No. 2 (1953): Hydra Springs compression spring catalogue

In this document

This commercial bulletin, the second issue ("Issue No. 2") of the "New Series" dedicated to Hydra Springs compression springs, presents two industrial models manufactured by the Wales-Strippit Corporation p. 18.

Model 52300

This spring exists in three series according to stiffness: 750 series at 20,000 #/in (pounds per inch), 625 series at 11,000 #/in, 500 series at 4,500 #/in p. 18. A dimensioned diagram indicates a diameter of 1¾ inches and dimensions from 3⅜ to 3¾ inches, with a ¾-16 NF thread on the "Force Adjuster" used for fine adjustments p. 18. An associated force/stroke graph shows the evolution of force (from 2000 to 8500 lb) according to the piston stroke, from 1/8 to 3/4 of an inch p. 18.

Model 53050

Longer, this second model displays lower stiffnesses: 750 series at 10,000 #/in, 625 series at 5,500 #/in, 500 series at 2,200 #/in p. 18. Its dimensions range from 4¼ to 5 inches for a diameter of 2¼ inches, with the same ¾-16 NF thread p. 18. Its force/stroke graph covers a longer stroke, from 1/4 to 1½ inches p. 18.

Summary table of stiffnesses

The text specifies that force and stroke can be modified by changing the preload or the Comproils (proprietary fluids) p. 18. A "Design Considerations" section touts the benefit of Hydra Springs for high-force and short-stroke applications, with efficiency gains announced of "300% to 1200%" compared to coil springs of equivalent size, depending on the stiffness p. 18.

Context

Wales-Strippit was an American manufacturer of industrial components; its "Hydra Spring" division marketed these hydraulic springs as a compact alternative to conventional metal springs, for tooling, presses, or other industrial uses. This type of document belongs to a series of technical bulletins (Hydra News) that the firm distributed to present its catalogue.

Paul Magès, a Citroën engineer developing the hydropneumatic suspension of the future DS at that time, was closely interested in competing or complementary hydraulic solutions, whether they were American liquid springs or systems like Dowty's.

Archivist's perspective

This technical catalogue, with no visible handwritten annotation in the transcription, seems to have been kept by Magès as a documentary watch on hydraulic spring technologies available in the United States.

It is part of a larger collection of Wales Hydra News bulletins present in the collection, notably number 1 on tension springs and number 3 on the flexibility of identical springs, suggesting a systematic collection of this promotional series by the Citroën teams, probably in connection with internal reflections on the "Hydra-Springs" springs mentioned in 1955.