GB735875A - Apparatus comprising a touch finger for automatic adjustment of the height of the burner in burner cutting machines - Google Patents

Abstract

735,875. Automatic control systems. MESSER GES., A. May 22,1952 [May 22, 1951No. 13019/62. Class 38 (4). [Also in Group XXII] In means for automatically adjusting the height of a burner by a reversible electric motor the motor is controlled by a touch finger which makes only intermittent contact with the work. In an embodiment a burner 8 is adjustably mounted on a casing which is raised or lowered by a motor 9 driving a rack and pinion 11, 10. A touch finger 6 in the casing which may rest on the work around the burner is raised by an intermittently energized solenoid 5. The lower part of the finger 6 may be of refractory material. Contacts 12, 13, 14, adjustable for sensitivity, are provided in the casing, the contacts 12, 14 forming a switch in the circuit of a solenoid 16 controlling a switch for current supply to rotate the motor 9 in one direction and the contacts 13, 14 similarly operating a solenoid 15 to control rotation of the motor 9 in the opposite direction. The contact 14 is tensioned to engage the contact 12 when the finger 6 is raised but when the finger 6 falls under its own weight or by spring pressure to engage the work at the correct distance a stop 14a holds the contact 14 midway between contacts 12, 13. A motor 1 rotates a cam disc 2 which permits engagement of contacts 3, 3a to energize solenoid 5 during greater part of its rotation and breaks this engagement to make contacts 3a, 4 to allow possible operation of motor 9 during the remainder of its rotation. In operation the burner is set at the correct distance above the work with the finger 6 on the work and contact 14 midway between contacts 12, 13. With cam 2 allowing engagement of contacts 3, 3a solenoid 5 lifts finger 6. On rotation of the cam 2 the solenoid 5 is de-energized, the finger 6 falls and shortly after the contacts 3a, 4 are made. If the burner 8 is at the correct height the stop 14a positions the contact 14 midway between the contacts 12, 13 but if the burner is too high the stop 14a engages the contacts 14, 13 to energize solenoid 15 to make its switch and supply current to motor 9 to lower the burner 8 and casing. If the burner is too low the contacts 12, 14 are made to operate solenoid 16 to effect raising of the burner 8 and casing. The cam disc 2 may be replaced by two or more oppositely rotatable discs. The position of the finger 6 may be transmitted to control means for motor 9 by pneumatic or hydraulic means, by alteration in a capacitance or inductance circuit or by photo-electric means.