Abstract: A dashpot wherein a fitting including a calibrated bleed orifice formed therein is detachably retained in a valve body which houses a check valve and forms a part of a diaphragm chamber.

Abstract: A pressure switching valve device including: a valve adapted to open and close an orifice defined in a valve seat; a diaphragm cooperating with the valve and so loaded as to maintain the valve in its open or closed position; and an atmospheric density compensating mechanism in engagement with the diaphragm to compensate for the opening and closing operations of the valve in response to the variation in atmospheric density, whereby the valve is opened and closed by impressing a given pressure on the diaphragm. This valve device features that the direction of a force exerted on the diaphragm so as to maintain the valve in its normally open or closed position is in coincidence with the direction of a force exerted by the atmospheric density compensating mechanism.

Abstract: An alarm device for use in an exhaust gas recirculating system wherein part of exhaust gases from an internal combustion engine is introduced back into a suction system of the engine to thereby lower the combustion temperature of the engine, thus reducing the amount of nitric oxides contained in the exhaust gases. This alarm device is of the type which detects abnormal recirculating condition of recirculating exhaust gases to thereby warn of the abnormal operation of the exhaust gas recirculating system. The features of this alarm device are that the variation in flow rate of exhaust gases flowing through the exhaust gas recirculating passage communicating the exhaust gas system with a suction system is detected according to the pressure, whereby when the pressure thus detected deviates from the predetermined value, the abnormal-condition indicating device is driven to warn of the abnormal recirculation of exhaust gases.