Method and apparatus for welding conduits
US4642154A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1982 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | Dec 15, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C66/9592
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A heating wire embedded in any one of several types of shaped elements is fed current by an electrical control apparatus for a time interval which is a function of the ohmic resistance of the wire and the type of shaped element. The type and resistance are automatically determined in advance by measurement of the wire impedance which indicates type and of the ohmic resistance. Welding time is selected from a predetermined directrix depending on resistance, and the directrix itself is chosen on the basis of type by the impedance measurement. A count representative of the time is stored in a counter and pulsed down to zero while current is delivered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.