| 摘要 |
<p>993,465. Sawing. UNITED STATES STEEL CORPORATION. June 21, 1962 [June 30, 1961], No. 24011/62. Heading B5L. [Also in Divisions B3 and G1] Apparatus for automatically adjusting the stop 42 of a hot-metal cutting machine, such as a saw or shears, the stop being attached to a carriage 40 movable along a body base 18 by a power-actuated means 52, 54 connected to a reversible motor 48, comprises a temperaturesensing element 58 and means for applying voltage to the motor in accordance with the output of the element. As described, the machine has a saw 6 for cutting a workpiece 4, such as a structural-steel beam, which is moved along a conveyer 2 into engagement with the stop 42. The stop is carried by the carriage 40 and is movable into and out of the path of the beam 4 by a bell crank system 46 operated by a reversible motor 44. The carriage is movable along the body base 18 by a screw- and-nut arrangement 52, 54 driven through reduction gearing 50 by the reversible motor 48, and the body base 18 is movable along rails 20 by rack-and-pinion gearing 22, 24 driven by a worm 26 rotated by a reversible motor 28 under the control of a switch 30. The body base is moved by operation of the switch 30 until the stop is in a position corresponding to the desired cold length of the beam as indicated by a pointer 36 against a scale 38. Thereafter the stop is adjusted in accordance to the temperature of the beam by a voltage supplied from the temperature sensing element 58, which comprises an optical pyrometer, to the motor. The pyrometer is connected to a D.C. amplifier 68, the output of which is fed to a reversible motor having two shafts 76. One shaft is connected to the slider 78 of a linear potentiometer in the circuit to the amplifier, and the other shaft is connected to the slider 86 of a non-linear potentiometer in a circuit including a scaling potentiometer manually adjustable according to the desired cold length of the beam, a potentiometer 108 having its slider 106 mechanically connected to the shaft of the motor 48, and a D.C. amplifier having its output 104 connected to the motor 48. Damage to the saw is prevented by actuation of a switch which automatically disconnects the motor 48 from the carriage 40 as the saw is swung into its cutting position.</p> |
