Protector for arc welding

Abstract

Abstract PURPOSE: To enable the perfect protection of the eyes from weld arc by controlling the start and end of welding as well as the modulation of the transparency of liquid crystal cell shield spectacles at fixed timings and letting light be shielded when a flash is detected. CONSTITUTION: When a power source switch S and torch switch TS are turned on, a relay CR1 operates to open its normally closed contact CR1' to cause the signal to a liquid crystal cell LCD to become nonconducting, due to which the applied transparent type LCD is de-energized and its transparency begins to decrease. On the other hand, the operation of a timer TR1 causes the time-limiting operation contact TR1' to be closed with a delay for a fixed time and therefore at the time when the shield filter has sufficiently decreased of its transparency, the welding flash of the welding machine AM is generated. Next, when ordinary welding is suspended and crater welding is started, the switch TS opens but the contact of the photo detecting means PH having been opened through detection of the flash is in a nonconducting state as far as the flash exits. Hence, the LCD maintains the non-transparent state. When the flash extinguishes, the time-limiting operation contact TR2' of the timer TR2 closes with a delay for a fixed time and the LCD becomes transparent. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Susumu Nishikawa
• 👤 Manabu Nishikawa

Bibliographic Details