Follow-up control means in swinging-arm flame-cutting machines

Follow-up control means in swinging-arm flame-cutting machines comprising a scanning element which is arranged at the outer component arm of the swinging arm carrying the cutting torch, and in coaxial relation to the latter and which is advanced by drive means likewise arranged on the outer component arm to follow automatically the contour of a pattern having the configuration of a part to be cut from a workpiece, characterized by the following features:

• (a) the scanning element comprises a photo-electric scanning head (24) which together with the feeding means (26) forms an assembly (23) seated at the outer guide rod (14) of the swinging-arm (16) for rotation about the torch axis (57, 27);
• (b) the feeding means (26) comprises a feed wheel (39) which is driven by a feed motor (36) and which rides on an end plate (40) fixed to the frame of the flame-cutting machine (10, 60) which extends in parallel to the supporting surface (19) for the pattern (20) and to the plane of movement of the torch (21), respectively the point of contact (42) between the feed wheel (39) and the said end plate being arranged at the point where the torch axis (57, 27) projects through the contact surface (43) of the end plate (40), and the center plane of the said feed wheel (39) which comprises the torch axis (57, 27) extending perpendicularly to its axis of rotation (41);
• (c) the scanning head (24) comprises a conventional arrangement of photo-electric detectors picking up the directional changes of the contour of the pattern and generating a control signal characteristic of any deviation of the contour of the pattern (20) from the momentary feeding direction, which signal is supplied to a swivel control motor (33) which, in response to the said control signal, rotates the scanning head (24) together with the drive means (26) into the orientation conforming to the contour of the pattern;
• (d) the pattern (20) is arranged in a plane extending between the scanning head (24) and the workpiece and in parallel to the latter and to the end plate (40), and the torch (21) is connected with the outer guide arm (14) by means of a U-shaped arm (24) encompassing the pattern (20) at a certain distance.