Method and apparatus for making electrical heater pad
US4933038A · kind A · utility
Inventor
Key dates
| Filing date | Oct 24, 1988 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Oct 24, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T156/1741
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of forming an electric heater pad having a continuous resistance heater wire which zig-zags transversely back and forth in longitudinally spaced runs secured intermediate two insulating sheets, the method comprising: (a) laying the wire inbetween the sheets by successive passes back and forth transversely between the sheets, (b) drawing the two sheets with the wire therebetween between two first pressure rollers to bond central areas of the sheets together leaving border strips on each transverse slide edge of the sheets unbonded, and (c) subsequently, bonding the sheets together over the border strips, wherein each successive pass comprises: (1) catching the wire between the sheets in a nip between the first rollers near the juncture of the border strips and central areas at one side, (2) drawing the wire transversely across the sheets to beyond the side edges of the sheets at the other side where tension is applied to the wire forming it into a straight run extending transversely across the sheets so that the straight run is promptly caught in the nip and secured between the sheets over said central areas, and (3) wherein before the step (1) of catching the wire in the n…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.