SE315798B - - Google Patents

Abstract

1,100,676. Thermal copying apparatus. VIEWLEX Inc. June 18, 1965 [Dec. 8, 1964], No. 25849/65. Heading G2A. In a thermal copying machine, the original and copy sheets are passed together between rollers 8 and 9. Roller 8 is a glass cylinder within which is adjustably housed a heat lamp 6 and reflector 7, so that the heat is concentrated on the line of contact between the rollers. The sheets are fed in through slot 3, passing between guides 17, 18, between the rollers, and between further guides 24, 25 to the exit 4. Thus the sheets take an S- shaped path through the machine, which minimizes overall slippage between the sheets. As they enter slot 3, the leading edge engages a projection 20a of a feeler 20, pivoting it clockwise about a shaft 20', and so closing a switch (21, Fig. 6, not shown) to energize the lamp. The sheets also engage another projection 20b of the same feeler, so that the lamp remains energized until the trailing end leaves projection 20b. A thermostat switch keeps the motor which drives the rollers running after the main switch has been turned off until the lamp has cooled sufficiently not to cause any damage to stationary rollers. Similarly the rollers are arranged to idle when the machine is on but has no sheets in it. The speed at which the sheets pass through the machine can be manually set, and then automatically adjusted by suitable circuits to compensate for fluctuations in the lamp temperature. A blower 30 for cooling is provided. If the rollers become jammed, an automatic switch arrangement shuts off the lamp.