Abstract: A vibration damping and isolation apparatus including a passive damping mechanism and an active enhancement mechanism. The passive damping mechanism operates to dissipate vibratory and shock forces applied to the vibration damping and isolation apparatus. The passive damping mechanism includes first and second spaced damping elements. A first resilient structure connects the first damping element to the second damping element to define a primary fluid chamber between the first and second damping elements. The passive damping mechanism further includes a second resilient structure that defines a secondary fluid chamber which is in fluid communication with the primary fluid chamber via a fluid flow orifice. A fluid fills the primary fluid chamber, the secondary fluid chamber and the fluid flow orifice.
Abstract: The present invention utilizes the integrated circuit manufacturing process to produce integrated circuits including bias circuits which implement active devices having uniform gain and gate threshold characteristics. The uniformity of these active devices increases when they are tightly clustered in an integrated circuit chip. Precise linear control of constant current output to a load is realized by maintaining a gate voltage in the linear operating region for a plurality of similarly configured, uniformly fabricated and doped current mirrors.
Abstract: Two windshield wiper blades are powered by separate electric motors. The blades overlap and when one blade is at its reversal point the other blade leaves part as the other blade begins to return to park. The position of the blades is encoded. The blades, if synchronized should be at identical locations and position codes at the same time. Motor power to the blade that arrives first is be removed, allowing the blade to coast. If the other blade still does not arrive at the position after an elapsed time, the first to arrive blade is dynamically braked. Intermittent wiper operation is provided in a way that initiates an immediate wipe if wiper delay is changed while the blades are parked.
Abstract: An apparatus for controlling an adjustable-speed electric motor. The actual motor speed is sensed and compared with a commanded motor speed. A speed error signal, which depends on the difference between the actual and desired values of motor speed, is derived and applied to a proportional-plus-integral control circuit which converts it into a first torque command signal. The speed command signal is converted into a second torque command signal proportional to the rate of change of the speed command signal. The second torque command signal is added to the first torque command signal to provide a torque command signal. A control circuit responds to the torque command signal by controlling the operation of the motor in accordance with the torque command signal.
June 6, 1988
Date of Patent:
September 26, 1989
Otis Elevator Company
Masao Iwasa, Yasutami Kito, Masayuki Mori
Abstract: A safety device for stopping an elevator car or counterweight has a brake shoe on one side of a guide rail, and, on the other side, two leaf springs and a roller. The springs define a tapered area, and the roller is pulled by a governor to engage the rail, which trips the roller, causing it to be forced into the tapered area and forcing the brake shoe against the rail. The roller engages a soft metal stop when the device is operated and this stop is worn away during each operation, which permits the roller to move higher on each operation; this compensates for any wear on the brake shoe. The governor is attached to the car or counterweight.
Abstract: A polyphase induction motor propels an elevator car. The motor is powered by a multiphase inverter which receives power from a battery. The inverter is controlled in such a way as to control the frequency and amplitude of the power supplied to the motor in order to control the motor's speed, acceleration, and slip. That inverter control is accomplished by sensing the motor's speed and in response providing predetermined slip and torque signals. The slip can be controlled over a range which can provide negative slip, by which power is regenerated into the battery, which is thereby charged, and positive slip for motoring torque. A charger also charges the battery. The motor and its controls are thereby ostensibly isolated from the power system that supplies power to the charger, the battery handling the peak power requirements.
Abstract: An elevator system using a linear induction motor for propulsion. The linear induction motor is mounted in the elevator counterweight along with a battery, motor control equipment, and battery charger. The counterweight is guided by a tubular rail which acts as the motor armature.
Abstract: A flapper valve having a negative rate characteristic is variably opened by an external force and controls fluid pressure to a piston which moves, in response to this pressure, in order to return the valve to a null position. A positive rate flapper valve applies force to the negative rate flapper valve and balances the fluid pressure in the negative rate flapper valve, thus providing high sensitivity negative flapper valve operation in the null position region and a negative rate in the region to overcome piston friction, without instability.
Abstract: A method for assembling a pressure gauge which employs a removable metal safety plate. The gauge movement, comprising a Bourdon tube, pointer, gauge dial and gear mechanism is mounted on both sides of a metal safety plate and the entire assembly is then inserted into the gauge case and fastened in place.
Abstract: Exhaust gas is recirculated to an intake manifold of an engine by a shut-off valve and a fluidic amplifier for modulation in accordance with different engine parameters. The shut-off valve is normally biased to a closed position and it is opened to permit recirculation in response to a signal received from a fluidic NOR gate which operates in accordance with position of a carburetor throttle, engine speed and engine temperature. The fluidic amplifier includes a power jet chamber receiving a supply of exhaust and a vent chamber in fluid communication with a venturi disposed in the exhaust manifold, a receiver chamber and a pair of control jets. One of the control jets may be in fluid communication with the intake manifold or with a carburetor venturi. The other control jet may be open to atmospheric pressure compensated for the effect of changes in air density or engine speed.