Abstract: A slide type vacuum pump has a cylinder bore with a cylindrical piston reciprocatingly slidably fitted therein and defining a vacuum pumping chamber. A seal element is housed in an annular groove around the piston defined by a radially extending annular surface and an axially extending cylindrical surface. The seal element includes an inwardly radially extending annular portion axially abutted against the annular groove defining surface and an axially extending cylindrical portion slidingly sealing against the cylinder bore. A first spring member has an inwardly radially extending annular portion axially abuttingly holding the annular seal element portion against the annular groove defining surface, and several axially extending resilient finger portions each angled outwards somewhat and springingly pressing the cylindrical seal element portion radially outwards against the cylinder bore to effect sealing therebetween.

Abstract: An exhaust gas recirculator for an internal combustion engine having an exhaust pipe, an intake manifold and a carburetor throttle valve. The exhaust gas recirculator comprises an EGR passage which makes the exhaust pipe communicate with the intake manifold, an EGR controlling valve and an EGR valve respectively arranged in the upper and lower portions of the EGR passage. The EGR valve operates in association with the carburetor throttle valve for metering the flow of EGR gas. The EGR controlling valve is separated by a diaphragm into an EGR gas chamber communicating with the EGR passage between the EGR controlling valve and the EGR valve and a negative pressure chamber communicating with the intake manifold.