Abstract: The shape of a back-up ring is a V-shaped sectional shape. In the back-up ring, an annular concave surface part having a V-shaped sectional shape serving as a valley toward a high-pressure side is formed on a surface part on a side that faces a seal ring, and an annular convex surface part having a V-shaped sectional shape serving as a peak toward a low-pressure side is formed on a surface part opposite to the side that faces the seal ring. When a high pressure is applied from a high-pressure side, the back-up ring is deformed such that V-shaped angles of an annular concave surface part and an annular convex surface part are increased as the annular concave surface part is pressed against the seal ring, and is brought into close contact with a housing and a shaft.

Abstract: A power transmitting apparatus can include a gear-stage clutch comprising alternately arranged driving clutch discs and driven clutch discs; hydraulic chambers for actuating a hydraulic piston; and hydraulic oil supplying ports communicating with oil passages opening on the side surface of the input shaft for supplying the hydraulic chambers with hydraulic oil from the oil passages to actuate the hydraulic piston. Power can be transmitted at a predetermined gear ratio by engaging clutch discs of the gear-stage clutch by selectively supplying the hydraulic chambers with hydraulic oil. An annular sealing member can be fitted in a recessed portion formed around each opening of the hydraulic oil supplying port on the outer circumference of the input shaft. The recessed portion can have a flattened bottom surface on which the sealing member is seated so that it is contacted with the flattened bottom surface of the recessed portion.

Abstract: An oil seal for reciprocation motion including a seal main body, a resin backup ring, and a holding member. The seal main body includes a seal lip that can be in sliding contact with a reciprocating shaft. The backup ring is disposed such as to support the seal lip from the atmosphere side to ensure durability of the seal lip. In the backup ring, at least a single annular groove is provided on the inner peripheral surface opposing the reciprocating shaft. The annular groove can hold a lubricating material. The holding member holds the backup ring between the holding member and the seal main body in a sandwiched-state. The inner peripheral surface of the backup ring forms a taper that increases in diameter from a sealed side towards an atmosphere side in the axial direction.

Abstract: An oil seal (1A) has an outer member (2) fitted to a crankcase (100), an inner member (3) integrally rotatably fitted to a crankshaft (101), and a first movable lip (4) disposed in the gap (G1) formed by the outer member (2) and the inner member (3). The first movable lip (4) is disposed such that it is not in contact with the outer member (2) when rotation of the crankshaft (101) is stopped and that it is displaced in the direction to approach the outer member (2), coming into contact with the outer member (2) to close the gap (G1).

Abstract: In a method of working a recessed portion 2 in a headrest stay 32 which is provided in the stay portion 32 of the headrest stay 3 formed of a pipe, a recess 2? is preformed by pressing against the stay portion 32 an outer peripheral portion 4a of a first punch roller 4 for preforming having a rounded portion 47 on the outer peripheral portion 4a in a side view. Subsequently, an outer peripheral portion 7a of a second punch roller 7 on the outer periphery portion 7a of which a punch portion for final forming has been formed is directed toward and pressed against the recess 2?, so as to form a recessed portion 2.

Abstract: A reed valve includes a vibration suppressing member for suppressing transmission of vibration, caused due to opening and closing operations of a reed piece, to a fixed mounting portion of an engine part to which the reed valve is mounted. The vibration suppressing member includes an elastic annular projection formed on at least one of an outer peripheral surface of a gasket fitted around an outer peripheral edge of a valve plate and a pair of upper and lower surfaces of the gasket. The elastic annular projection is elastically engaged with the fixed mounting portion when the mount portion of the valve plate is mounted to the fixed mounting portion.

Abstract: A drum brake includes a brake drum attached to an axle, and a brake panel. The brake drum includes a disc portion and a cylindrical portion extending from an outer peripheral end portion of the disc portion towards the brake panel. On an outer peripheral end portion of the cylindrical portion, there is mounted a seal member. The brake panel includes an annular flat surface portion, and a cylindrical projecting portion projecting from an outer peripheral end portion of the annular flat surface portion towards the brake drum so as to surround the seal member. The seal member has plural resilient axial sealing lips and at least one resilient radial sealing lip. The axial sealing lips are in sealing contact with the annular flat surface portion, and the radial lip is in sealing contact with an inner peripheral surface of the cylindrical projecting portion.

Abstract: Polymer Insulator which is characterized by a rode having on its outer surface an umbrella-like housing or insulator layer and having end portions which are formed so as to freely expand with at least one splitting groove; a fixture having a mounting hole in which the end portion of the rod is inserted and which has an inner surface tapering inwards against which the outer surface of said rod abuts in its expanded state; and a wedge fixed in said mounting hole, the wedge being inserted into a splitting groove formed in the end portion of the rod when the end portion of said rod is mounted into said mounting hole of said fixture, the top end of the wedge having an engaging portion which is held in the splitting groove thereby to cause the whole wedge to engage in the splitting grove.

Abstract: A pressure roller is disclosed which comprises: a metal core; an elastic layer formed around the metal core; and a top layer provided over the elastic layer, the top layer having a thickness of not greater than 0.1 mm and being made of a fluororesin, the fluororesin having a coefficient of dynamic friction of 0.25 or more. The pressure roller is capable of forming a high quality image free of image failure and has excellent durability. The fluororesin having a coefficient of dynamic friction as high as 0.25 or more can be obtained by incorporation of a second component having high viscoelasticity into a fluororesin such as PFA, FEP, MFA or EPA.

Abstract: A water-proof sealing structure for an electric junction box including a main box having a first fitting portion and a water-proof covering having a second fitting portion to be mated with the first fitting portion; wherein either the first or second fitting portion is integrally formed with an elastomer-made fitting groove having a narrowed portion therein, while the other fitting portion is formed with a locking projection wall provided with a stopper; wherein the locking projection wall is suppressed by the narrowed portion when inserted into the fitting groove, forming simultaneously an air-keeping section between a top end of the locking projection wall and an innermost portion of the fitting groove.

Abstract: A fluid-flow controlling apparatus having a fluid-flow stopping state and a fluid-flowing state, wherein the valve body can be held positively at a determined position thereby to prevent any fluid leaks even when the pressure of supplied fluid is increased, said apparatus is characterized by: valve casing connected to the end of a fluid-supplying tube and comprising a valve seat and a slidable valve body; a reciprocating arm which is restricted by means of stoppers in its movement vertical to the flow direction in said valve casing; a connecting plate for connecting said valve body and said reciprocating arm together, said connecting plate being located in a direction parallel to said flow direction in said fluid-flow stopping state; a link mechanism for connecting a float to said reciprocating arm.

Abstract: In a method for examining the quality of adhesion in a vulcanized rubber-adhesively bonded metal part made by adhesively bonding a rubber member to a metal with an adhesive for rubber applied thereon in a vulcanization-forming or molding, a small rubber test piece is previously vulcanization-formed or molded together with the rubber member onto a portion of the metal surface other than the bonded joint of the rubber member, and the small rubber test piece is teared off from the metal surface, thereby discriminating the part whether the adhesion is good or bad.

Abstract: An oil seal of the type having a metallic reinforcement rig whose outer peripheral portion is oil-tightly fitted into a housing, characterized in that after the formation of fabrication of said metallic reinforcement ring, the latter is subjected to a nitriding hardening process so that its durability of a raw material of said metallic reinforcement ring; and a seal lip of formed over the inner peripheral edge portion of an annular flange portion of said metallic reinforcement ring.