Oil cylindrical rotational damper

A rotational damper, the damper comprising:

• a housing having an annular space containing a viscous fluid;
• a cylindrical rotor accommodated in said housing and which receives a damping action from the viscous fluid, wherein the cylindrical rotor comprises a cylindrical head, and wherein the cylindrical rotor is hollow throughout the length thereof;
• an annular cap provided independently of said rotor and engaged with the housing, which retains said rotor in said housing;
• a ring-shaped first sealing member disposed between said rotor and said cap;
• and
• a ring-shaped second sealing member disposed between said rotor and said housing.

An assist grip comprising:

• (a) an arm supported so as to be rotatable between a first angular position during use and a second angular position during non-use, with said arm biased to return from the first angular position to the second angular position;
• and
• (b) a damper for damping arm rotation, the damper including:
• a housing containing a viscous fluid;
• a cylindrical rotor accommodated in said housing for receiving a damping action from the viscous fluid;
• an annular cap having a central aperture and provided independently of said rotor, and which retains said rotor in said housing;
• a ring-shaped first sealing member disposed between said rotor and said cap;
• and
• a ring-shaped second sealing member disposed between said rotor and said housing;
• said cylindrical rotor including a cylindrical head having an end side with a first hollow cylindrical portion threat, said first hollow cylindrical portion being passed through the central opening of said annular cap, with said first sealing member disposed between said first hollow cylindrical portion and the central aperture of said annular cap.

An assist grip comprising:

• (i) an arm supported so as to be rotatable between a first angular position during use and a second angular position during non-use and biased to remain in said second angular position;
• and
• (ii) a damper for damping rotation of said assist grip, said damper including:
• a housing containing a viscous fluid, the housing having an inner cylinder;
• a cylindrical rotor accommodated in said housing and for receiving a damping action from the viscous fluid;
• an annular cap having a central aperture and provided independently of said rotor and which retains said rotor in said housing;
• a ring-shaped first sealing member disposed between said rotor and said cap;
• and
• a ring-shaped second sealing member disposed between said rotor and said housing;
• said cylindrical rotor being provided with a cylindrical head, having opposite ends and having a first hollow cylindrical portion at one of the end sides, said first hollow cylindrical portion being passed through the central aperture of said annular cap;
• said cylindrical rotor having a second hollow cylindrical portion at the other end side of said cylindrical head, and a portion of said inner cylinder of said housing entering into said second hollow cylindrical portion;
• said cylindrical rotor having a damping cylinder provided independently of said cylindrical head;
• and
• said second sealing member being disposed between said second hollow cylindrical portion and said damping cylinder.

A rotational damper, comprising:

• a housing having an inner cylinder and outer cylinder disposed concentrically with each other and an annular space formed between the inner cylinder and the outer cylinder containing a viscous fluid;
• a cylinder rotor accommodated in said housing and which receives a damping action from the viscous fluid, wherein the cylindrical rotor is hollow throughout the length thereof;
• means for preventing viscous fluid leakage;
• and
• an annular cap provided independently of said rotor and mounted to said housing, and which retains said rotor and said sealing member in said housing.