Abstract: A metal-sawing machine includes a rocking system whereby the saw blade is enabled to rock in a cutting plane in which the work is cut, wherein the rocking motion is controlled so as to conform to the cutting stroke, which is determined in accordance with the shape and size of the work. The machine ensures that the rocking motion of the saw blade fully participates in cutting the work unlike the known metal-sawing machines in which the rocking motion is partially wasted in cutting "air".

Abstract: The invention provides a metal-sawing machine including a guide frame vertically movable with respect to a work to be cut, a saw carrier capable of rocking in the cutting plane with respect to said work, a pair of servo-cylinders one on the left-hand section and the other on the right-hand section of said saw carrier, each of said servo-cylinders being connected at one end to said guide frame at a first pivotal point while the opposite end thereof is connected to said saw carrier at a second pivotal point, a rocking motion control means for alternately differentiating the distance between said first and second pivotal points of each of said servo-cylinders, and a guide means for preventing said saw carrier from horizontal displacement with respect to the line of cutting action of the saw blade while in its rocking motion.

Abstract: A hydraulic system for controlling the cutting feed speed of a saw frame of a sawing machine, such as a band-sawing machine, includes an improved control valve on the discharge line enabling the fluid to draw off from the hydraulic cylinder, the control valve being capable of amplifying changes of pressure in the cylinder occurring in response to changes of cutting resistance to the saw blade, thereby securing a proper control over the cutting feed speed of the saw frame irrespective of the size and weight of the saw frame.

Abstract: A hole making position control unit for a hole making machine suitable for making rivet holes and bolt holes in shaped steel. This control unit mainly comprises a marked plate having marks thereon, a photoelectrical apparatus for detecting the mark and a hole making head interlocked with the photoelectrical apparatus, and controls the action of the hole making head in accordance with the arrangement of the marks, which are arranged at the positions corresponding to the centers of holes to be made and to the turning positions of the moving direction of the hole making head. Each mark has a width to be detected in the detecting direction of the photoelectrical apparatus, so that during the detection of the mark the hole making head is instructed to decelerate, and when the detection is finished the hole making head is instructed to stop.

Abstract: A method of controlling the cutting feed speed of a saw frame of a band-sawing machine or a similar machine, whereby the change of cutting resistance to the saw blade is detected as a change in pressure of an oil pressure cylinder supporting the saw frame and by transforming such change into a voltage change by means of a piezoelectric element, the flow rate of a flow control valve provided in the pressure oil discharge circuit of the oil pressure cylinder is controlled by said detected voltage or the like and thereby the cutting feed speed is changed in response to the change of cutting resistance so as to maintain the cutting resistance to the saw frame at an optimum.

Abstract: A method of controlling the cutting feed speed of a saw frame of a band-sawing machine or a similar machine, whereby the change of cutting resistance to the saw blade is detected by sensing the change of load on the back of the saw blade or the change of pressure of an oil pressure cylinder supporting the saw frame and by transforming such change into a voltage change or amperage change by means of a piezo-electric element, the flow rate of a flow control valve provided at the pressure oil discharge circuit of the oil pressure cylinder being controlled by said detected voltage or the like and thereby the cutting feed speed being changed in response to the change of cutting resistance so as to maintain the cutting resistance to the saw frame at an optimum value.