Abstract: A substantially U-shaped sealing strip and a sealing strip are formed on an outer container of the electric storage device as first sealing strips by heat sealing processing so as to surround an electrode housing portion. Further, a safety valve portion having a narrower sealing width than other sites is formed in the center of the substantially U-shaped sealing strip. Furthermore, a second sealing strip is formed on the outer container to oppose the safety valve portion at a predetermined distance. When an internal pressure of the electrode housing portion exceeds a prescribed value due to overcharge, etc., a sealing surface of the safety valve portion peels away, thereby opening the safety valve portion such that gas in the electrode housing portion is discharged from the opened safety valve portion. Electrode material and an electrolyte are also discharged, but trapped by the second sealing strip.

Abstract: An inertia lock type synchronous clutch mechanism in which elastic ring members on blocking rings are engaged by a shift sleeve splined to a clutch hub at a plurality of sloped circumferential cam portions protruding from the inner circumference of the sleeve so that the blocking rings are moved axially into frictional engagement with tapered cone portions of synchronized gears by the force applied through the elastic ring members by the axial shifting action of the shift sleeve. Each of the elastic ring members is formed with a plurality of outwardly convex portions corresponding to the respective cam portions and concave portions between the convex portions so that the elastic ring member concave portions engage grooves formed in the outer circumference of the boss portion of each of the blocking rings, whereby excess bulging of the elastic ring member is prevented.