Abstract: An automatic recording bias current setting apparatus comprises a bias current generating circuit for generating a bias current with varied level of the bias current, a testing signal generating circuit for generating two kinds of testing signals having different mid and high frequencies of an audio signal, by independently varying the levels of the testing signals, a recording and reproducing circuit for recording the two kinds of testing signals with the bias current onto a magnetic recording medium and reproducing the same, and a bias current detecting circuit for detecting the level of a bias current. The recording and reproducing circuit repeats an operation in which the two kinds of testing signals are recorded onto the magnetic recording medium and then reproduced with independently varied levels of the two kinds of testing signals under the same bias current obtained from the bias current generating circuit, for each of the different varied bias currents.

Abstract: In a photo-mask blank, a transparent substrate is covered with a shading layer including chromium and chromium carbide. On the shading layer is an antireflection layer which includes chromium and chromium nitride. The shading and the antireflection layers are deposited in the same hollow space by sputtering. The etch rate of the shading layer is adjustable to that of the antireflection layer to make both etch rates equal and, thereby, to reduce undercuts appearing at the shading layer.

Abstract: A method and apparatus for reducing the energy consumption of fluorescent lighting energized by an alternating voltage source comprising sensing for a particular amplitude of the alternating voltage and upon sensing such voltage amplitude establishing a given time period which is a fraction of a cycle of the alternating voltage. At the end of the given time period actively connecting the alternating voltage source to the fluorescent lighting whereby the lighting is energized for a portion of the cycle, and for a given time interval at the start of operation continuously actively connecting the alternating voltage source to the fluorescent lighting so that the components of the fluorescent lighting can efficiently warm up.

Abstract: An exercising device, especially for physical therapy, is formed of two planar members connected at an angle and sandwiching therebetween a sponge member of angular conformation to constitute a compressible structure. The sponge member is replaceable to provide selectivity with respect to compression and with respect to angular relationship between the planar members. A further planar member is optionally and adjustably connected to the compressible structure to provide a heel rest. A strap is provided to encircle the compressible structure and to hold an operator's extremity, such as a foot or hand, thereon. Flat rigid members are optionally usable to enable the device to be employed for dorsiflexion rather than plantiflexion. In this case the structure is mounted on top of the foot with the rigid members sandwiching the foot and exercising device therebetween.

Abstract: A positive displacement rotary pump based on the spiral principle in which the piston is given a complex orbital motion by a crankshaft drive, the piston being also pivoted to a second guide element, this pivot point reciprocating along an open path. The second guide element is constructed to provide compactness and ease of manufacture.

Abstract: A vacuum booster device which comprises a booster shell; a booster piston axially slidably accommodated in the booster shell and having a central boss portion and a disc portion around the outer circumference of the boss portion; and a diaphragm superposed on the rear surface of the disc portion and having an inner circumferential bead fitted to the central boss portion of the booster piston and an outer circumferential bead fitted to the circumferential wall of the booster shell. The booster piston and the diaphragm cooperate with each other to divide the interior of the booster shell into a front side first working chamber communicated with a vacuum supply source and a rear side second working chamber selectively communicated with the first working chamber or the atmosphere via a control valve operatively connected to an input member. The front and rear walls of the booster shell are connected to each other by tie rods extending through the disc portion of the booster piston and the diaphragm.

Abstract: A tile-lined pipe and its method of manufacture comprising a tubular pipe member having a layer of tile elements on the inner surface to form a lining therefor. The tile elements extend one after another along helical lines and are formed by subdividing larger tiles transversely along score lines so that the adjoining faces of the subdivided tiles will be in closely conforming adjoining relation. Within the tile elements is an erodible layer. The structure is encompassed by resin saturated fiberglass. The resin serves to absorb energy from impacting particles.

Abstract: An anti-lock braking system for a four-wheel vehicle having a pair of left and right front wheels and a pair of left and right rear wheels in which one pair of wheels carries a greater load than the other, the system comprising a first braking pressure regulator operative to simultaneously reduce the braking pressures in a pair of wheel cylinders of the left and right front wheels in response to an anti-lock control pressure for the front wheels and a second braking pressure regulator operative to simultaneously reduce the braking pressures in a pair of wheel cylinders of the left and right rear wheels in response to an anti-lock control pressure for the rear wheels. A late-period operation type anti-lock control pressure supply device is associated with the pair of left and right wheels carrying the greater load to supply the anti-lock control pressure to the corresponding regulator upon detection of locking of a wheel later than the other in the pair of left and right wheels carrying the greater load.

Abstract: A digital filter having a band-pass filter characteristic or a band-elimination characteristic is constructed by a designing procedure comprising a step in which a function H(z) is obtained from a Z-transform of a bi-quad transfer function H(s) in a Laplace transfer form comprising conjugate pairs of poles and zeros, and establishing a center frequency of the filter characteristic from the radius of a circle in the s-plane in which the poles and zeros of the bi-quad transfer function H(s) are on the same circle, a step in which a quality factor Q of the filter characteristic is established so as to satisfy the following two equations (I) and (II) in which .sigma..sub.1 is the real-axis projection part and .omega..sub.1 is the imaginary-axis projection part of the above two poles in the s-plane, and .sigma..sub.2 is the real-axis projection part and .omega..sub.

Abstract: A device for controlling the load distribution and speed of gas turbine systems and particularly gas turbine engines comprising for each engine a fuel control unit having a proportionally acting speed governor and a master speed governor for a common output shaft of the gas turbine systems and a load distributing control device. The master speed governor forms signals from the speed deviation and the load distributing control device forms signals from load deviations of the gas turbine systems from one another. The signals influence the speed set points of the proportionally acting governors through electronic operational amplifiers forming signal outputs from the deviation signals and preferably an auxiliary quantity and electronic summing amplifiers for adding the signal outputs together to form the control signals.

Abstract: A system for the displacement of two thrust reversers for two jet engines of an airplane. Each thrust reverser has a drive motor operated by compressed air, a valve controlling the flow of compressed air to the motor, a set-point indicator including an input piston controllable by the action of compressed air, a differential transmission, and a feedback system from the motor to the differential transmission. The valve is actuated by the input piston and the motor via the differential transmission. The displacement of the two thrust reversers is halted by a system of stops acting on the input pistons at identical intermediate points in the paths of travel thereof and the displacement is thereafter continued after the thrust reversers have both reached their intermediate points in their paths of travel by deactivation of the stops.

Abstract: A signal pickup device in a rotary recording medium reproducing apparatus comprises a turntable placed thereon with a rotary recording medium recorded with an information signal as variations in geometrical configuration, for rotating the rotary recording medium, a reproducing stylus provided at a tip end of a cantilever, for making contact with and sliding against a recorded region of the rotary recording medium upon reproduction to reproduce the information signal, a resonator having a resonance frequency which varies in accordance with the above variations in geometrical configuration, and a conductive ribbon having one end connected to the reproducing stylus and the other end connected to the resonator to electrically connect an electrode of the reproducing stylus with the resonator, where the conductive ribbon is in a curved and bent state upon reproduction of the rotary recording medium.

Abstract: A horizontal scanning frequency multiplying circuit comprises a flip-flop supplied with an input horizontal synchronizing signal having a horizontal scanning frequency f.sub.H of a television signal, a phase-locked-loop (PLL) for producing a signal having a frequency Nf.sub.

Abstract: A D.C. motor driving circuit comprises a first transistor circuit comprising an initial stage transistor and a terminal stage transistor respectively connected in Darlington pairs, for supplying a current to a D.C. motor, coupled between the D.C. motor and a power source, a switching transistor coupled to the initial stage transistor of the first transistor circuit, and a second transistor circuit including a transistor coupled in parallel to the first transistor circuit, for supplying a current to the D.C. motor. The switching transistor is turned ON when applied with a driving signal voltage to put the first transistor circuit in an ON state. The current supplied to the D.C. motor decreases as a rotational speed thereof increases after starting of the D.C. motor. The first transistor circuit is turned OFF when the rotational speed of the D.C. motor reaches a speed near its constant normal rotational speed. The D.C.

Abstract: A turbine blade adapted for use with hot gases comprising a radially inward portion of metal including a core projecting radially outwards on which is supported a ceramic portion of airfoil section enclosing the core. The inner end of the ceramic portion forms a continuous surface contour with the metal inward portion. The ceramic portion extends no more than one-half of the total span of the blade and, preferably, about one-third of the blade span. In a particular embodiment, the wall thickness of the ceramic portion can increase in an radially outwards direction.

Abstract: A multiple-layer wall is provided for a hollow body to sustain high thermal and mechanical loads and to afford adequate thermal insulation. The wall has, on the inside, a heat and/or wear resistant ceramic inner layer and, surrounding it, a preferably prestressed retaining layer of fiber reinforced plastic. An intermediate layer of a thermally insulating ceramic material can also be provided. The wall can also have a retaining layer of metal. At least the retaining layer is shrink-fitted. The retaining layer of metal and/or the intermediate layer moreover can be deposited by a sintering process. Prestressing is achieved also by the shrinkage resulting from the sintering process. As a result of prestressing, the inner layer, when under internal pressure, comes under substantially no circumferential tension or under circumferential compression only. The wall is used especially with precombustion chambers of Diesel engines or with cylinder barrels or internal combustion engines.

Abstract: A fuel-injection valve comprises an electromagnetically actuated armature attached to the needle-like stem of a valve head. In order to promote control of fuel flow under varying conditions the valve opens by moving the valve head downstream from its valve seat and the stroke of the valve head is limited by a mechanical stop situated downstream of the valve seat.