Eiki Watanabe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: A linear motor elevator system comprising a sheave disposed in the upper portion of an elevator hoistway, a length of rope wound around the sheave, a movable member connected to said rope, a primary winding disposed only on a first side of said movable member and a secondary conductor extending within and along the hoistway in association with said primary winding to constitute a linear motor. The system may comprise a brake unit disposed on a second side of said movable member which is opposite to said first side and a guide rail disposed within said hoistway for being engaged by said brake unit.
Abstract: A hydraulic elevator control apparatus comprises an induction motor for driving a hydraulic pump which sends and receives a fluid, an inverter circuit for determining the number of rotations of the induction motor using variable-voltage variable-frequency, and a speed control apparatus which detects the voltage and current of the induction motor, calculates the number of rotations of the induction motor on the basis of the detected voltage and current, and controls the inverter circuit on the basis of the calculated number of rotations.
Abstract: A drive control apparatus includes a magnetic field in which a magnetic field gradient is provided by applying a magnetic field to the magnetic fluid to produce an apparent specific gravity gradient in accordance with the magnetic field gradient. A control member immersed in the magnetic fluid moves under the influence of buoyant force from a gradient of the apparent specific gravity produced in accordance with the magnetic field gradient, so that a driven body interlocking with the control member is driven at a low noise level.
Abstract: In an elevator system comprising a machine room and an elevator car, as the elevator car moves along a hoistway between a plurality of floors, a radio system permits wireless communication between the machine room and the elevator car. As the elevator car moves along the hoistway, the distance between the elevator car and the machine room varies. To effect stable signal transmission and avoid receiver saturation when the elevator car is in close proximity to the machine room, the output of the transmitter or the sensitivity of the receiver is varied in accordance with the distance between the elevator car and the machine room.
Abstract: This invention relates to a control system for an induction motor which has power factor control means for altering the power factor of the input current of a converter composed of self-arc extinguishing elements, such as transistors, to vary the d.c. output voltage of the converter to perform a pulse-amplitude modulation control in a variable voltage, variable frequency controller for controlling the rotating speed of the induction motor by the converter of a sinusoidal wave input to reduce noise generated by the operation of the motor.
Abstract: This invention relates to an elevator signal transmitting equipment characterized in that a shielding body of a magnetic shielding material envelops a transmitting line laid along a shaft through which a cage travels and a portion of a coupling device extending toward said transmitting line, the transmission and reception of signals being realized through the magnetic coupling between said transmitting line and said coupling device to control the operation of said cage, a path through which a part of said coupling device travels being left not enveloped.
Abstract: A passenger conveyor apparatus comprises a plurality of steps endlessly connected to each other and guided along a circulating conveyor path, each of the steps having a tread on which a passenger stands and a riser adjacent the forward edge of the tread, at least a portion of the riser of the steps being constituted by a light transmissive material, and a light source for throwing light on the light transmissive material of the riser, the light source being disposed inside the circulating conveyor path.
Abstract: A control apparatus for an escalator wherein a low speed operation is performed in the absence of passengers at the escalator, and a high speed operation is performed in the presence of passengers at the escalator the alternating current of a three-phase A-C power source is converted by frequency conversion means into a three-phase alternating current of low frequency, with which an induction motor is energized to perform the low speed operation, so that the induction motor is rotated near a synchronous speed corresponding to the low frequency, to realize the low speed operation of high efficiency.Moreover, when passengers have been detected, the frequency of the alternating current from the conversion means is gradually raised, and the conversion means is thereafter switched to the three-phase A-C power source upon detecting the synchronism of this alternating current with the alternating current of the three-phase A-C power source, so that smooth switching free from shocks becomes possible.
Abstract: A passenger conveyor system is provided with a driving unit disposed at an upper horizontal portion of the system and a linear motor disposed at a midway portion of the system for driving the passenger conveyor, thereby not requiring the provision of expensive linear motors over a full rise of the system, and adding a linear motor to only a portion of the conventional system, while the comfort of the passengers is considerably improved.
Abstract: An elevator such as an escalator having a display device presenting, whenever necessary, a display of matters to be noted upon a predetermined special operation (for example, when conveying a wheelchair) while making the display disappear during normal operation of the escalator so as to avoid unsightly appearance. This is also effective in preventing the inadvertent overlooking of the matters displayed. The display device comprises a liquid crystal layer; a pair of electrodes disposed on opposite sides of the liquid crystal layer, one of the electrodes being a transparent pattern electrode having a pattern corresponding to the display of the matters that should be taken note of, the other electrode being a transparent common electrode; and an electric power source for supplying electricity to the electrodes.
Abstract: An elevator control system connected to a source of three-phase alternating current which is rectified by a converter to direct current which is converted to a variable-voltage variable-frequency A.C. voltage which, in turn, drives the elevator hoist motor. A resistor and a switch are connected across the D.C. terminals of the converter. When the motor is operating in the regenerative mode, the switch is closed to permit the regenerated circuit to flow through the resistor which dissipates or consumes the regenerated power. When the regenerated power being consumed by the resistor is detected to exceed a predetermined value, the excess regenerated power is returned to the A.C. source through a regenerative inverter.
Abstract: An elevator wherein an electric motor for driving the cage of the elevator is driven by the use of alternating current produced by an inverter, comprising a converter which feeds D.C. power to the inverter and which is so arranged that a plurality of transistors are connected into a bridge corresponding to the number of phases of an A.C. power source connected on the input side of the converter and that diodes are connected to the respective transistors in inverse parallel relationship. In addition, a battery to be used in emergency is connected on the input side of the converter. The converter is controlled in the pulse width modulation in the normal state of the A.C. power source, and the converter connected to the battery is controlled as a chopper during the stoppage of the power source, thereby making it possible to run the elevator at high speed even with the battery of low voltage.
Abstract: Series circuits consisting of diodes for blocking reverse currents are inserted between the upper and lower arms of bridge-connected transistors constituting an inverter, and contacts of a contactor adapted to close upon a stoppage of power supply are respectively connected in parallel with the series circuits so as to short-circuit the series circuits of the diodes, whereby the inverter is changed-over from a current type inverter to a voltage type inverter upon the stoppage of the power supply. Thus, even in an elevator employing the current type inverter, a rescue operation during the stoppage of the power supply can be performed with a simple circuit arrangement employing a D.C. power source.
Abstract: A control apparatus for an elevator comprising a temperature sensor which senses the temperature of the rotor of an induction motor during the stoppage of a cage, and a voltage/frequency control device which calculates the secondary winding resistance value of the induction motor on the basis of the output value of the temperature sensor and which vector-controls a power conversion device by the use of the calculated secondary winding resistance value, so that during the stoppage of the elevator, the temperature of the rotor is measured to alter the secondary winding resistance value necessary for the vector control, whereby the optimum control can be performed.
Abstract: A control apparatus for an elevator comprising loss impartation means to impart a loss to a hoisting machine for a cage; cage position detection means to detect the position of the cage; and control means to control the loss impartation means on the basis of an output signal of the cage position detection means so as to adjust the loss in accordance with the position of the cage; wherein by adjusting and controlling the loss, the resonance of a mechanical system composed of the cage, a balance weight, a hoisting rope, etc., is suppressed to improve riding conditions in the elevator car.
Abstract: An elevator control system has a converter for converting an AC power from a normal power source to a DC power having a variable voltage, an inverter for inverting the DC power from the converter to an AC power having a variable voltage and a variable frequency, and an induction motor energized by the inverter to drive an electric motor. When a power failure occurs on the normal power source as sensed by a power failure sensor, the converter is connected to an emergency power source to be fully fired to generate a DC power higher in DC voltage than that due to the normal power source.
Abstract: An elevator drive motor 1 is normally energized from an AC power source 8 via an AC-DC converter 4 and a DC-AC inverter 3. When the power source fails the elevator is braked and the inverter is supplied from an emergency battery 11 to access the nearest floor for passenger discharge. If a fault occurs in the inverter it is disconnected from the motor by opening a switch contact 15a, and the closing of a further contact 15b enables the converter to energize the motor in a "reverse function" mode from the battery.
Abstract: A variable-voltage variable-frequency elevator control apparatus is disclosed in which a circuit for the consumption of regenerated power produced during regenerative braking is provided on the DC side of the apparatus rather than on the AC side. During regenerative braking with an emergency generating unit in operation, regenerated power is consumed by the consumption circuit on the DC side of the circuit and is prevented from being returned to the emergency generating unit. This prevents the production of voltage notches commonly produced during regenerative braking by thyristor commutation in conventional circuits. Because no voltage notches are produced, a reduction in the size of the emergency generating unit can be achieved. In addition, since it consumes DC power rather than 3-phase AC power, the consumption circuit requires fewer elements than in conventional control apparatuses.
Abstract: An electric elevator car drive has a sheave having grooves lines with non-metallic linings, and a controller which stops the elevator car when the linings are damaged. The grooves of the sheave have a plurality of metallic projections projecting thereinto which are normally covered by the non-metallic layers but which come into secure engagement with the cable when the layers are damaged. A fault detector detects the damage done to the layers, and, when damage to the layers are detected, the controller stops the elevator car at the nearest floor at which it can be stopped safely without damage to the cables suspending the elevator car.
Abstract: The disclosed elevator control systems comprises a three-phase AC source and an emergency three-phase AC generator supplying selectively an AC power to a thyristor Leonard type converter connected to a hoist DC motor for driving an elevator car, and a firing control circuit formed of a microcomputer. With the converter connected to the AC source, the microcomputer calculates a firing signal from a command and an actual speed signal for the hoist motor, and an input current to the converter according to a firing program stored in it and delivers the firing signal to the converter to control its firing in the symmetric mode. Upon a suspension of the AC power, a power failure detecting relay drops out to connect the converter to the emergency generator, decrease the command speed signal and cause the microcomputer to calculate similarly a firing signal but by using the decreased command speed signal and another firing program stored in it.