Multiple rate coil spring assembly
US5868383A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Mar 27, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/481
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An automated method for the manufacture of a coil spring assembly including inserting coil springs having predetermined multiple spring rates into respective individual pockets of a continuous pocket strip in a predetermined order. The predetermined multiple spring rates of at least one coil spring may differ from that of the other coil springs, and each of the multi-rate coils has at least two different spring rates. One or more wires having a substantially uniform thickness are coiled to form the multiple rate coil springs before insertion into the continuous pocket strip. The wire is preferably coiled to produce a coil spring having at least two different diameters and at least two different pitches. The method also includes cutting the spring-filled strip into one or more desired lengths, placing at least two spring-filled lengths adjacent to each other; and attaching adjacent lengths together. A coil spring assembly may thus be provided with one or more firmness zones. Perimeter coil springs may also be inserted into pockets corresponding to the outer perimeter of the coil spring assembly, and border wire may be added for stiffness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.