Abstract: A first base supporting a lower blade is reciprocated horizontally by rotation of a first motor in one direction only. A second base supporting supporting an upper blade is reciprocated vertically by rotation of a second motor in one direction only. A signal corresponding to the movement of said work, preset length data and a signal corresponding to the rotation of said first motor are fed to first base numerical control means, and the first base is controlled during forward run of the first base by the first base numerical control means such as to follow the running of the work with the work projected by the preset length from the first base.

Abstract: In a reciprocating travelling shear in which a tool post travels reciprocatingly in the travelling direction of a travelling material and a cutting tool held by the tool post is made to move vertically by press mechanism to cut the material, the press mechanism is driven by a first DC motor, which is controlled by first numerical control means, the reciprocating travelling of the tool post is controlled by a second DC motor, which is controlled by second numerical control means, and the second numerical control means supplies a cut command to the first numerical control means thereby to drive the first motor when the tool post has travelled a predetermined distance.

Abstract: A cutting control apparatus for cutting, by a rotary type flying cutter, a sheet, pipe or like material fed by a feeder. On the basis of a synchronous cutting length corresponding to setting of a blade speed change mechanism of the flying cutter and one of a travelling speed signal of the material and the revolving speed of a blade of the cutter, a reference speed signal is produced for the other of the material travelling speed and the blade revolving speed. One of a signal related to length-measuring pulses corresponding to the distance of travel of the material and a signal related to rotation pulses corresponding to the rotation of the blade is applied as an additive input to an adder, and the other is applied as a subtractive input to the adder.

Abstract: In an AC-DC converter for converting an AC power by a six-phase, half-wave or three-phase, full-wave back-to-back or anti-parallel connection thyristor bridge to a DC power for input to a load, while the current to the load is small, the converter is actuated as a converter of a three-phase, half-wave back-to-back connection bridge, thereby to enable an alternate supply of negative and positive currents to the load. Letting the output by the AC-DC converting operation of the three-phase, half-wave back-to-back connection bridge and the output by the other converting operation be identified as main and auxiliary outputs, respectively, as the load current increases, the auxiliary output is also supplied to the load.

Abstract: A numerical control servo system, in which a set value in a setting memory and a measured numerical value corresponding to a controlled variable are subtracted one from the other by means of a digital subtractor and an object to be controlled is controlled based on the subtracted value in a manner to reduce the subtracted value to zero, such a control being repeatedly performed. Prior to each control, the output from the digital subtractor at the end of an immediately preceding control is written in a deviation memory. During the control, the value stored in the deviation memory is added directly or indirectly to the set value to compensate for the controlled deviation.

Abstract: In a servomechanism in which a cutter is rotated by a servomotor to cut a moving member in a predetermined rotational angular range of the cutter and the servomotor is controlled in accordance with the difference between the number of length measuring pulses generated corresponding to the distance of movement of the moving member and the number of rotation measuring pulses generated corresponding to the rotation of the cutter, a correcting signal is read out of a memory with respect to each rotational angular position of the cutter in the above said predetermined rotational angular range. The correcting signal corresponds to the component of unit rotational distance of the cutter in the direction of travel of the moving member at each rotational angular position of the cutter in its predetermined rotational angular range.