Abstract: A distance measurement device includes: a mirror disposed so as to be tilted relative to a rotation center axis; a drive unit configured to rotate the mirror about the rotation center axis; a photodetector configured to detect reflected light, of laser light, reflected in a distance measurement region; and a condensing lens disposed on the rotation center axis and configured to condense the reflected light reflected by the mirror, on the photodetector. The mirror has a shape elongated in one direction and is disposed such that a short axis thereof is tilted relative to the rotation center axis in a direction parallel to a plane including the rotation center axis. A width in a short-axis direction of the mirror is smaller than a width of a lens portion of the condensing lens as viewed in a direction parallel to the rotation center axis.

Abstract: A gear is provided with double rows of teeth having the same pitch circle, which are deviated from each other in the circumferential direction. The gear can be mutually engaged with another counterpart identical with no backlash between the meshed teeth, whereby a rotary motion can be efficiently and smoothly transmitted between the rotating gears engaged without involving vibrations and noises.

Abstract: A method of producing an oriented electrical steel sheet having superior magnetic properties comprises the steps of, hot rolling a slab containing 0.8 to 6.8% of Si, 0.008% of Al acid soluble, the balance being Fe and accompanying impurities, by weight to form a strip, cold rolling the strip, primary-recrystallization annealing, coating the strip with an annealing separator, and finishing annealing, a nitriding treatment being effected after the primary recrystallization annealing but before the start of the secondary recrystallization of the finishing annealing. According to the present invention, with an atmosphere oxidizing degree (PH.sub.2 O/PH.sub.2): x in a soaking process in said primary recrystallization annealing an annealing is effected in an atmosphere which has an oxidizing degree (PH.sub.2 O/PH.sub.2): y in a range defined by the following inequality, at a temperature ranging from 650.degree. to 800.degree. C. in the heating process, for at least 5 secs.

Abstract: The present invention relates to a process for preparing a unidirectional silicon steel sheet having a high magnetic flux density which comprises heating a silicon steel slab comprising by weight 0.025 to 0.075% of carbon, 2.5 to 4.5% of silicon, 0.015% or less of sulfur, 0.010 to 0.050% of acid-soluble aluminum, 0.0010 to 0.012% of nitrogen, 0.050 to 0.45% of manganese and 0.01 to 0.10% of tin and optionally 0.0005 to 0.0080% of boron with the balance being iron and unavoidable impurities, at 1200.degree. C.

Abstract: Disclosed is a process for preparing a thin grain oriented electrical steel sheet having a final thickness of 0.05 to 0.25 mm from a silicon steel slab comprising 0.050 to 0.120% by weight of C, 2.8 to 4.0% by weight of Si and 0.05 to 0.25% by weight of Sn, wherein the starting silicon slab further comprises up to 0.035% by weight of S and 0.005 to 0.035% by weight of Se, with the proviso that the total amount of S and Se is in the range of 0.015 to 0.060% by weight, 0.050 to 0.090% by weight of Mn, with the proviso that the Mn content is in the range of {1.5.times.[content (% by weight) of S+content (% by weight) of Se[} to {4.5.times.[content (% by weight) of S+content (% by weight) of Se[} % by weight, 0.0050 to 0.0100% by weight of N, and {[27/14].times.content (% by weight) of N+0.0030} to {[27/14].times.content (% by weight) of N+0.0150} % by weight of acid-soluble Al.

Abstract: A reclining chair having a seat section slidably connected to a frame section. A rearward end portion of the seat section and a back-rest section are rockably and separably connected to a lower end portion of the back-rest section and to a rearward end portion of the frame section, respectively. A friction brake apparatus for non-stepwise controlling the sliding movement of the seat section is fitted to one side of the seat section, and through the brake apparatus the seat section is connected to the frame section by coupling means.

Abstract: A method for producing high magnetic flux density grain oriented electrical steel sheets or strips having a B.sub.8 characteristic in the rolling direction of not less than 1.9 Wb/m.sup.2 by hot rolling, continuous annealing for precipitation of the AlN, cold rolling into the final thickness, decarburization annealing, and finishing annealing. The cold rolling includes a final rolling at a strong reduction between 81 and 95%.