GB546098A - Improvements in or relating to oxygen jet cutting machines - Google Patents

Abstract

546,098. Cutting by fusion. HANCOCK, L. J. March 7, 1941, No. 3147. Addition to 534,714. [Class 83 (iv)] In a flame cutting machine as described in the parent Specification, in which the height of the burner above the work is maintained substantially constant by gearing driven by a reversible electric motor controlled through relays by runners moving over the work, electric contacts are provided to bring about energization of the relay initiating raising of the burner when the runner falls through a predetermined distance independently of the burner, a limit stop being provided to operate the contacts to de-energize the relay when the burner reaches a predetermined height. A counterweighted switch lever 50 with contact spring 56 wipes over contacts 57, 57a, 58 separated by insulating segments, the contacts 57, 57a being connected in common to the relay controlling the motor for raising the burner 3 and the contact 58 being connected to the relay for causing the motor to lower the burner. The lever is pivoted at 55 in the box 17 secured to the burner and is connected through a rod 51 provided with knuckle joints 53, 52 to the yoke 12 fixed to the rods 10 carrying the runners 11. The yoke 12 may be longitudinally adjusted on one of the rods 10 and secured by the clamp 13 to vary the normal distance between the end of the burner and the work. The rod 51 may be adjustable for a similar purpose. The spring 56 normally rests between contacts 57 and 58. When the runner rises the lever 50 connects with contact 57 and the relay is energized to cause the motor to lift the burner. When the runner falls the contact 58 is engaged and the motor lowers the burner. When the runner travels beyond the edge of the work it drops and the lever engages contact 57a so that the burner is raised. The downward movement of the burner when the contact 58 is in circuit and the upward movement when contact 57 or 57a is in circuit, are controlled by limit stops 62, 63. In the former case after the parts 11, 10, 12 and 51 and the burner are lowered a predetermined distance, the stop 62 strikes the top of the burner holder 2 and the lever 50 thus turns clockwise into neutral position to stop the motor. In the latter case when the parts 11, 10, 12, 51 and the burner rise a predetermined distance the stop 63 engages the holder 2 to check the rod 64 which causes lever 67 to operate the yoke 12 so that the lever 50 is lowered to its neutral position to stop the motor. The position of the burner relatively to the parts 11 may be set by lowering the burner by the hand wheel, the parts 11 which are in contact with the plate thus rising to set the lever 50. The lever 50 may also be handcontrolled by an arm 73 on a spindle 72 carrying a pointed arm 72 co-operating with indicating points and provided with a ball catch engaging one of three notches in the switch box 17.