Hot melt induction heater and method
US5414247A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1993 |
| Grant date | May 9, 1995 |
| Priority date | — |
| Expiry date | Dec 29, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C66/919
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A fiber optic cable extends into the housing of an induction heater and has a sensing end positioned to confront a part being heated. Infrared radiation from the part is transmitted by the cable to a transducer. The transducer converts the infrared energy into an electrical signal that is used by a control circuit to control the heating operation. The control circuit has an internal electronic timer that is used in normal operation and to detect certain failure conditions. In normal operation, electromagnetic pulses are provided to the heater at a predetermined power level until the part reaches a predetermined temperature. Then the control circuit adjusts the power level to hold the part at the temperature for a brief holding period. The timer is used by the control circuit to detect failure to reach a desired temperature after a maximum delay and to detect dropping of the temperature below a minimum level during the holding period. The control circuit also detects overheating of the workpiece. The control circuit adjusts and terminates the power level through a silicon controlled rectifier which receives a pulse train from the control circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.