Abstract: The unload circuit includes a pump oil passage that connects between a hydraulic pump and a direction control valve, a tank oil passage that connects between the direction control valve and a hydraulic tank, a pressure compensating flow control valve interposed between the pump oil passage and the tank oil passage, a pilot operated relief valve interposed between the pump oil passage and the tank oil passage, and an unloading solenoid valve interposed in a vent oil passage of the pilot operated relief valve. The failure diagnosis device includes a pressure sensor that measures a pressure of the pump oil passage, and a controller that receives a pressure signal from the pressure sensor. The controller performs failure diagnosis of the unload circuit based on a differential pressure between a first pump oil passage pressure during unloading and a second pump oil passage pressure during on-loading.

Abstract: A locator device used to provide location information for a user. The device comprises a case containing a deflated airfoil and an inert gas cylinder. The inert gas flows into the airfoil upon puncture of the cylinder by a valve having a puncture valve. The valve is operated by a twist from a user. The twist of the valve causes the puncture valve to be driven into the gas cylinder, thereby puncturing the gas cylinder. The gas flows into the airfoil until it is fully inflated. The inflation of the airfoil automatically pulls a pin from a quick-release assembly thereby allowing the airfoil to be released and deployed upon full inflation. The airfoil is anchored to the area of the user by attachment to the invention. All of the invention's elements are contained within a case having easily separable halves.

Abstract: A pump failure alarm system which is provided in a hydraulic working machine comprising hydraulic pumps driven by a prime mover, delivery lines joining with one another into one common delivery line on the downstream side, check valves provided in the delivery lines upstream of a point where the delivery lines join with one another, a hydraulic cylinder driven by a hydraulic fluid introduced through the common delivery line, and a hydraulic reservoir. The pump failure alarm system comprises pressure sensors for detecting respective delivery pressures of the hydraulic pumps, bypass lines having one ends connected to the delivery lines at points upstream of the check valves and the other ends connected to the hydraulic reservoir, solenoid switching valves for opening and closing the associated bypass lines, an alarm display unit for giving an alarm in correspondence to each of the hydraulic pumps, and a controller.

Abstract: The invention is directed to a pressure monitoring system for monitoring a hydraulic pressure which is supplied from a fluid pump and accumulated in an accumulator. The pressure monitoring system includes an electric motor which drives the fluid pump to supply the hydraulic pressure in substantially linear proportion to a current fed to the motor, a current detection device which detects the current fed to the motor, and a pressure estimation device which estimates the hydraulic pressure accumulated in the accumulator in response to the current detected by the current detection device. A malfunction detection device may be provided for detecting a malfunction on the basis of the output of the pressure estimation device.

Abstract: An apparatus and method for producing sound, particularly unusual sound effects, wherein the apparatus comprises at least one diaphragm and a spring attached to the diaphragm, having a lowest resonance frequency less than 18 hertz. The apparatus includes a resonator affixed to the diaphragm.According to the method of the invention, sounds are produced on an instrument having a spring and a diaphragm connected to the spring by exciting an echophone frequency of the spring by either activating longitudinal motion of the spring, jerking at least one end of the spring in a longitudinal direction, longitudinally displacing and releasing a section of the spring, and moving at least one end of the spring longitudinally in a rhythmic motion to excite an echophone frequency.