Abstract: A servo control system has a motor for a control and a device for commanding target distance and velocity of movement of the control so as to actuate the motor in accordance with commands from the commanding device.

Abstract: A work holding device used in an external form cutting machine for printed boards, the cutting machine including a work mounting table movable in X direction and a cutter mounting spindle movable in Y direction perpendicular to X direction, comprising holding device disposed above the table, pushing device for pushing said holding device, elevating device for raising and lowering said holding device. The holding device and the elevating device engage with each other slidably in a vertical direction with the pushing device interposed therebetween. By virtue of these arrangements, the printed boards are surely holded, resulting in an uniform cutting surface of piled printed boards. Holding pins used in prior arts for holding printed boards are not required, resulting in an improved operational efficiency of the cutting machine.

Abstract: In a pressure foot used in an apparatus for drilling printed circuit boards, which includes a bearing for holding a spindle, and formed at the end portion thereof with an inner void space having a bottom hole for passing the drill bit, the end portion of the pressure foot is provided with an annular end surface possibly contacting with the printed circuit board and air injection ports for injecting compressed air into the inner space. The air injection ports are so directed that the air flow from each injection port is tangently contacts with the circumferential surface of the drill.

Abstract: An arc welding power source supplies a high voltage for the reignition of an arc after the polarity reversal of a welding current to prevent the destruction of circuit elements and ensure the stable and positive polarity reversal despite its reduced size, and also the occurrence of a spike voltage in a main circuit during the polarity reversal of a large current or alternatively the welding current during the polarity reversal is controlled to suppress a spike voltage during the current reversal.

Abstract: In a method of drilling a printed circuit board according to the present invention, an entry feed rate at which a drill is fed into the printed circuit boards during the initial stage of drilling is made slightly smaller than a drilling feed rate at which the drill is fed while it is drilling a hole through the printed circuit boards, so as to enhance the accuracy at which holes are located. One drilling operation includes a plurality of drilling feeds of the drill, and pulled-out positions of the drill which are reached by the drill between adjacent drilling feed rate are set within a range in which the pressure of a pressure foot is effective. This can prevent the stacked printed circuit boards from shifting and increase the accuracy at which the holes are located.

Abstract: A board exchanging apparatus comprising a first transfer device for transferring boards along a transferring path connecting a processing device and a feeder between the feeder and the transferring path, a second transfer device for moving a liftable board holding member along the transferring path and conveying the boards, a waiting device including liftable comb-like holding members superimposed in top and bottom relation and disposed at a location opposite to the processing device, a third transfer device for transferring the boards between the processing device and the waiting device, and a delivery device provded in the processing device.

Abstract: In an ink-jet recording device in which a nozzle is so excited that ink droplets jetted from the nozzle are alternately separated into large-diameter ink droplets and small-diameter ink droplets, and recording ink droplets to be stuck onto the recording surface are made to fly straight while nonrecording ink droplets are charged and deflected to be retrieved by a gutter, there are provided a nonrecording ink droplet sense circuit and a correction signal generator circuit for generating correction charging voltage when an ink droplet to be controlled is generated provided that the preceding ink droplet is a nonrecording ink droplet and the ink droplet to be controlled is a recording ink droplet.

Abstract: In a coordinates detecting device comprising: a cursor; a tablet in which conductors are arranged in a predetermined periodic pattern; and arithmetic means for calculating the position of the cursor according to the outputs of the tablet, correction values for correcting the errors which are caused in common with all the periods of the pattern and in correspondence to the positions in each of the periods have been stored in memory, and the position of the cursor calculated by the arithmetic means is corrected by using the respective correction value.

Abstract: A coordinate detection system is disclosed which comprises a pointer which is excited by current of a predetermined frequency. Two conductors are arranged on a tablet for producing voltages which depend on the position of the tablet at which the pointer is located. Selector wires are arranged at intervals of half cycles of the conductors and a processor computes the position pointed to on the tablet based on an output voltage obtained, while scanning selected selector-wire pairs, sequentially, from any selected selector-wire pair exceeding a predetermined set voltage. The processor provides an output indicating the phase difference between waveforms induced in said two conductors.

Abstract: An ink-jet printer including an ink jet nozzle for ejecting ink droplets onto the recording paper which is moved relative to the nozzle so that dots of ink are printed in the form of a pattern. The trajectory of flying ink droplets is deflected along the direction of the relative movement under control based on the measurement of the relative movement speed.

Abstract: In a tool failure detection apparatus for a working machine such as a drilling machine for circuit boards, light is irradiated onto a workable area of a workpiece, and reflection light from the workable area is picked up by an imaging unit to produce a video signal. A video signal indicative of at least either one of a tool image and a worked void image which is picked up within a predetermined region of a picture is sampled to calculate an image area. A comparator compares a calculated image area with a preset reference value indicative of normality of the tool to judge whether the tool is normal or broken.

Abstract: An apparatus for forming openings in printed circuit boards includes a work table for supporting the printed circuit boards, and at least one drilling unit movable relative to the work table. The apparatus uses drills each having a shank, a collar fitted around the shank at a predetermined position. For holding these drills, at least one first tool holding device is provided on the work table, and at least one second tool holding device of a magazine type for containing the drills parallel to each other is removably mounted above the work table. At least one transferring device is provided to operate to push a desired drill out of the second tool holding device of the magazine type, hold the pushed-out drill and transfer the same to a position where it is aligned with the drilling unit.

Abstract: While the excitation voltage of an ink jet nozzle is swept on the logarithmic scale, the generation state of ink droplets at a phase .theta..sub.k is examined. An excitation voltage value Vn generating an ink droplet of small diameter at the phase .theta..sub.k, an excitation voltage value Vn generating an ink droplet of large diameter at the phase .theta..sub.k, which is lower than vn, and an excitation voltage value Vn+1 generating an ink droplet of large diameter at the phase .theta..sub.k, which is higher than vn are stored. Difference values expressed asWn=vn-Vnwn=Vn-1-vnare derived on the logarithmic scale. Then the nozzle excitation voltage is set at such a value as to generate ink droplets and minimize the value of .vertline.Wn-wn.vertline..

Abstract: In an ink jet recording apparatus, an amplification-degree control circuit is associated with an amplifier circuit amplifying a detection signal indicative of the quantity of charge of charged ink droplets, so as to decrease the degree of signal amplification by the amplifier circuit when a charging signal is applied to a charging electrode charging the ink droplets, but to increase the degree of signal amplification by the amplifier circuit when the quantity of charge of the charged ink droplets is detected from the detection signal.

Abstract: A method of and apparatus for grinding a work by a surface grinder having a rotating grinding wheel with a flat grinding surface. During the grinding of the work, a support for the spindle of the rotating grinding wheel is moved in the direction of a thermal distortion of the support which is caused by the heat generated in a spindle head rotatably mounting the grinder spindle, thereby to obviate any reduction in the precision of grinding attributable to an inclination of the grinding surface caused by the thermal distortion of the support.

Abstract: An arc welder is provided with a phase control circuit by rectifying elements to simplify the construction of the arc welder and improve the performance and operability. The arc welder is further provided with a storage control circuit to enable the retrieval of stored data of the same welding conditions. A union/individual control circuit is provided to eliminate troublesome adjustment of potentiometers.

Abstract: An electric discharge machining apparatus capable of automatically optimizing the machining stabilizing condition including set voltage of machining pulse, duty factor of the pulse, electrode raising period and working fluid pressure, and hence capable of being full-automated. Each machining stabilizing condition is successively changed within a predetermined range and set when the maximum effective discharge generation rate is obtained. Spark machining is effected on the basis of the set value.

Abstract: In a machine tool, a tool failure detection equipment in which chips or particles resulting from the machining of a work are collected and whether the tool is intact or broken is detected from the quantity of collected chips or particles. Chips or particles are sucked by a suction means and the quantity of collected chips or particles is detected by an optical detecting means. When the detected quantity is less than a predetermined value, the tool is detected as being broken.

Abstract: An automatic welding line tracing method and apparatus for causing a welding torch to follow the welding line by using a single non-contact-type sensor for detecting the welding line which is continuously reciprocated to traverse the groove of two pieces to be welded. During the reciprocating motion of the sensor, the sensor generates output voltages E.sub.1 and E.sub.2 respectively obtained by detecting the both ends of the groove to obtain E.sub.1 -.delta. and E.sub.2 -.delta. on the basis of the detected voltages E.sub.1, E.sub.2 and a separately established reference voltage .delta., and an output voltage P.sub.S corresponding to the central position of the groove is obtained from E.sub.1 -.delta. and E.sub.2 -.delta. to thereby compare the voltage P.sub.S with a voltage indicative of the central position of the oscillating motion of the sensor to thereby cause the welding torch to follow the welding line in accordance with the difference between these two voltages.

Abstract: An automatic weld line copying apparatus has a non-contact type sensor including a core wound with an exciting primary winding which in turn is wound with a secondary winding a plurality of secondary coils differentially. The sensor is compact and able to detect, without contact, the distance from the flat surface or edge line of an object to be welded thus making possible accurate and efficient automatic welding of a small welding assembly with a complicated weld line.