Abstract: A tooth rolling flat die and a method for forming a tooth are provided. The die has the same service life as those of the conventional tooth rolling flat dies using oil coolant even if conducted by semi-dry forming. A first substantially quarter length portion of the leading teeth section of the die has a first surface roughness Rz of maximum height ranging from 20 to 35 &mgr;m, and a second substantially quarter length portion of the leading teeth section of the die has a second surface roughness Rz of maximum height ranging from 5 to 20 &mgr;m. The die is adapted for semi-dry forming the tooth.

Abstract: A helical gear tooth broach having an elongate body having a series of axially aligned and spaced teeth disposed thereon. The direction of tooth spaces or traces of the teeth in a longitudinally extending helical alignment and the direction of the gullets of the teeth in a side by side circumferentially extending helical arrangement are both oriented at a right-upward or a left-upward helix angle in common with each other.

Abstract: A wrist mechanism of an industrial robot is described which comprise first, second and third wrist elements rotatably supported relative to each other around respective rotation axes which are mutually inclined, which leaves a hollow space inside thereof free for passage of supply cables and pipes which are to be connected to a tool being secured to the robot wrist. The second and third wrist elements carries first and second ring-shaped hollow reduction units, and their respective output shafts rotates the second and third wrist elements, respectively, thereby the amounts of backlashes and flank wears in the transmitting gears as well as the amounts of reflected rotational movements of the second and third wrist elements affected by the rotational movements of the first and second wrist elements are reduced within fractions of the reduction ratios of each of the reduction units, which result the controllings of the positionings of the wrist elements become easy and accuracies thereof are increased.

Abstract: A wrist mechanism of an industrial robot is described which have a first ring-shaped hollow reduction unit secured to an arm of the robot, and a first hollow drive tube and a second ring-shaped hollow reduction unit secured to an output shaft of the first reduction unit, respectively. The wrist mechanism further have a second hollow drive tube and a third ring-shaped hollow reduction unit secured to an output shaft of the second reduction unit, respectively, and a third hollow drive tube secured to an output shaft of the third hollow reduction unit rotatably around a first axis. The first, second and third hollow drive tubes are connected to first, second and third wrist elements, respectively, to rotate each of the wrist elements relative to each other, which leave a hollow space inside thereof free for passage of supply cables and pipes which are to be connected to a tool being secured to the robot wrist.

Abstract: A method for manufacturing a solid lubricant film for cutting tools, having a hard material layer positioned on a tool steels, high-speed steels or cemented carbide substrate, includes the steps of: depositing on the hard material layer a solid lubricant oxide layer (MOX :0.2≦×<2) where the metal M is selected from Si, Zr, Ni, Fe, Co, Cr or combinations thereof. The thickness (t) of the solid lubricant oxide layer is 0.01 &mgr;m≦t<3.0 &mgr;m. The solid lubricant oxide film is deposited on the harden layer by heating a vacuum ion-plating chamber to a temperature of between from 150° C. to 450° C., and depositing on the coated cutting tool the solid lubricant oxide layer by an ion-plating. A negative bias charge is applied using a direct current of from −15 V to −1000 V or a high frequency alternating current equivalent to an effective negative bias charge of the direct current of from −15 V to −1000 V.

Abstract: An improved single-row multi-point-contact ball bearing for an electromagnetic clutch and pulley and for a compressor for an automobile air conditioner is provided, which has a low relative inclination between the inner and outer rings and rotatable at a high revolution of about 10,000 rpm, and yet inexpensive requiring a small axial space. A single-row four-point contact angular ball bearing is provided which comprises an one-piece inner and outer rings. Each raceway surface of the inner and outer rings is made to form a Gothic-arched configuration having two curved surfaces, and each radius of curvature of the two curved surfaces is made to range substantially 0.515 to 0.55 of the outer diameter of a ball.

Abstract: An improved vacuum carburizing method is provided which is easy to handle or to maintenance and low equipment costs without using hydrogen gas or acetylenic gas. The improved vacuum carburizing method comprises a carburizing treatment of workpieces made from steel material heated to about 900-1100° C. performed by introducing an ethylenee gas as a carburizing gas at a vacuum of 1-10 kPa in a carburizing furnace chamber.

Abstract: An industrial robot is provided which has a compact and of low height body operable within an operating range not exceed the height of the robot during operation, and yet is able to secure a wide operating range of the near front side of the robot. The robot has a fixed base, a rotary base mounted on the fixed base rotatably around a vertical swing axis, a first arm mounted on the rotary base rotatably around a horizontal first rotational axis, a second arm mounted on the first arm rotatably around a horizontal second rotational axis and a wrist mounted on the distal end of the second arm rotatably around a longitudinal axis thereof. The first arm is made operable to hang down in a position where the axis of the first arm is perpendicular to the installation surface of the robot and outwardly offset from the outer surface of the fixed base, the operating range of the first arm which interfere with the fixed base is made so small and the operating range of the front side of the robot is much enlarged.

Abstract: A cutting tool having cutting edges made of a high speed tool steel exhibiting very high wear and anti-chipping resistances, and sufficient toughness is provided. The high speed tool steel consists essentially of by weight C:0.6 to 1.8%, Si:1.2% max, Mn:0.5% max, Cr:3.5 to 5.0%, Mo:10% max, W:21% max, V:2 to 4% and Co:7 to 10%, the balance being Fe and incidental impurities, and the steel of the cutting edge comprise MC-type carbide grains each having a maximum equal value diameter of a circle ranging substantially 5 to 14 &mgr;m, and the MC-type carbide grains having an equal value diameter of the circle ranging substantially 5 to 14 &mgr;m have a ratio between short and long diameters ranging over substantially 0.3.

Abstract: An improved supporting device for wiring of electric cables for an industrial robot is provided which is adapted to house an increased number of electric cables and pipes without making the robot body of a high vertical height or large-sized. The supporting device has plurality of circular spaces divided by axial partition walls each extending along a concentric circle with respect to the rotation axis of the rotary base. A plurality of bundles containing a plurality of electric cables and/or pipe(s) are so installed in each of the circular spaces that each one end of the bundles is secured on the interior wall of the base and then, each bundle extends halfway along a center of one of the circular spaces, and then is turned back to form an U-shaped configuration and returns along a center of opposite circular spaces of the rotary base, and each of the other end of bundles is secured on the rotary base.

Abstract: An improved single-row multi-point-contact ball bearing for an electromagnetic clutch and pulley and for a compressor for an automobile air conditioner is provided, which has a low relative inclination between the inner and outer rings and rotatable at a high revolution of about 10,000 rpm, and yet inexpensive requiring a small axial space.A single-row four-point contact angular ball bearing is provided which comprises an one-piece inner and outer rings. Each raceway surface of the inner and outer rings is made to form a Gothic-arched configuration having two curved surfaces, and each radius of curvature of the two curved surfaces is made to range substantially 0.515 to 0.55 of the outer diameter of a ball.

Abstract: An improved solid cemented carbide ball nose end mill is provided which enables a cutting of a quenched or hardened difficult-to-machine material without any chipping or break of edge under the condition of a high speed and high load cutting. The improved end mill comprises a substantially semi-spherical ball nose portion provided with such cutting edges as to form a virtually S-shaped symmetrical configuration as viewed from the tip end and a tool body integral with said ball nose portion and having a peripheral cylindrical portion being provided with no peripheral cutting edge and a shank at the rear end thereof. The cutting edges extending from the tip end of the ball nose portion to the respective terminals positioned at the furthest at the vicinity of the border between the ball nose portion and the tool body are formed in the ball nose portion only. Preferably, each of a rake angle and a relief angle of the cutting edge is set between 0.degree. and -10.degree., and between 6.degree. and 16.degree.

Abstract: A hydraulic device comprises a variable displacement pump, a plurality of hydraulic actuators, a plurality of directional valves capable of controlling the delivery oil flowing into each of the actuators, a plurality of pressure compensation valves which compensate the pressures of respective directional valves, and a delivery oil flow rate varying means capable of controlling the pump delivery. At least one of the pressure compensation valves decreases its output flow to a particular actuator according to an increase in the loaded pressure of the particular actuator. With this arrangement, if the loaded pressure of the particular actuator suddenly changes, the loaded pressure attenuates to ensure stable operation of the hydraulic device. Further, the stable operation is fee of hunting for both low-load actuators and high load actuators, regardless of an independent operation or a compound operation.

Abstract: A grease composition for rolling bearings is disclosed which contains:(A) 100 parts by weight of a base oil having the kinematic viscosity of 40 to 200 mm.sup.2 /s at 40.degree. C.,(B) 5 to 65 parts by weight of a urea thickener, and(C) 0.05 to 10 parts by weight of zinc dithiocarbamate,the composition being free of boron nitride. This grease composition is suitable for application to rolling bearings in electrical components and accessory devices for automotive vehicles, such as alternators, electromagnetic clutches for car air conditioners, idle pulleys, electric fan motors, or the like.

Abstract: An electrically driven explosion-proof painting robot comprises a base having a first pressurized chamber, a rotary base having a second pressurized chamber, an inner arm having a third pressurized chamber and an outer arm having a fourth pressurized chamber. Each pressurized chamber is hermetically sealed and independently formed, can contain an electric motor connected with cables and is not in fluid communication with one another. Each pressurized chamber is supplied with pressurized air respectively by respective air pipes extending through the respective walls of the chambers. Each air pipe is made detectable its pressure respectively.

Abstract: A hydraulic device comprises a variable displacement pump, a plurality of hydraulic actuators, a plurality of directional valves capable of controlling the delivery oil flowing into each of the actuators, a plurality of pressure compensation valves which compensate the pressures of respective directional valves, and a pump flow control valve capable of controlling the pump delivery. Each of the pressure compensation valves decreases its output flow to a particular actuator according to an increase in the loaded pressure of the particular actuator. With this arrangement, if the loaded pressure of the particular actuator suddenly changes, the loaded pressure attenuates to ensure stable operation of the hydraulic device. Further, the stable operation is fee of hunting for both low-load actuators and high-load actuators, regardless of an independent operation or a compound operation.

Abstract: According to the present invention there is provided a wear resistant vane for alternate flow that is appropriate for a rotary compressor that employs HFC flow as an alternate refrigerant, and which vane possesses: a reciprocal or opposed characteristic in that it does not cause to wear a piston to which it contacts and nevertheless causes little wear to itself; a preferable corrosion resistance; and an ensured reliability, in that when employed for an operation that continues for an extended period of time there is no possibility of a surface layer suddenly peeling off.

Abstract: By utilizing Corynebacterium sp. N according to the present invention, massive amounts of the waste fluid containing high concentration ethanolamines can effectively be treated without causing an environmental pollution. According to the present invention, it is possible to treat the waste fluid containing ethanolamines in a small-scale manner. The apparatus for treating the waste fluid according to the present invention can readily be installed, and the initial and running costs such as a maintenance of the apparatus are inexpensive.

Abstract: The present invention relates to a method for dressing a hone of a honing wheel which is used for honing a gear to be finished. A dressing tool is brought into contact with the honing wheel under a predetermined constant contact pressure and during the reciprocal feed of the dressing tool. The amount of the contact pressure is maintained constant so as to gradually increase the in-feed of the honing wheel. This is useful in decreasing the number of transverse feeds of the dressing tool.

Abstract: In order to synchronize the operations of at least two industrial robots which can operate independently of each other in accordance with their respective operation programs, the time is obtained which is required for one of the robots serving as the master to move from one working position to the next position at which it operates jointly with the remaining robot. The remaining robot serving as the slave is moved from the position where it exists at present to another position corresponding to said next position, thereby synchronizing the operations of all the robots. An apparatus for such synchronous control comprises a program used to compute with a specified moving speed the interpolation movement due to which each robot is moved between the adjacent working positions and a program used to compute the interpolation movement with a specified moving time. In case of the asynchronous control, the robots move independently in accordance with their respective operation programs.