Abstract: A vehicle seat includes: a holder assembled to a back frame, the holder configured to receive a backrest load of a seated person via a pad member; a vibration device assembled to a rear side of the holder, the vibration device configured to give a local stimulus to a seated person's waist; an air massage device disposed in a through hole formed in a thickness direction of the pad member, the air massage device configured to locally press a seated person's back; and a lumbar support device configured to change a projecting amount of a receiving surface of a seat back, wherein the lumbar support device has a rod configured to be movable between an advancing position and a retreating position to change the projecting amount of the receiving surface of the seat back, and wherein the rod is disposed between the holder and the vibration device.

Abstract: A vehicle seat includes: a holder assembled to a back frame, the holder configured to receive a backrest load of a seated person via a pad member; a vibration device assembled to a rear side of the holder, the vibration device configured to give a local stimulus to a seated person's waist; an air massage device disposed in a through hole formed in a thickness direction of the pad member, the air massage device configured to locally press a seated person's back; and a lumbar support device configured to change a projecting amount of a receiving surface of a seat back, wherein the lumbar support device has a rod configured to be movable between an advancing position and a retreating position to change the projecting amount of the receiving surface of the seat back, and wherein the rod is disposed between the holder and the vibration device.

Abstract: A booster having a feature of stroke jumping. In this type of booster a power piston, which is actuated by the difference of fluid pressure acting on either side thereof, is so constructed as to be able to shift, in relation to a control piston with a built-in control valve for controlling the fluid pressure, within a certain limited distance. Between the output member of the booster and the two pistons, i.e., power and control, is disposed a power lever, which is abutted at either end thereof on the output portion of the two pistons and at the middle portion thereof on the output member, for transmitting the movement of both pistons to the output member, while allowing the relative movement of both pistons. The output stroke of this booster can be made greater than the input stroke by means of the relative movement of the power piston to the control piston.

Abstract: A booster utilizing fluid pressure which is provided with a power piston disposed between a constant-pressure chamber and a variable-pressure chamber for being actuated by the pressure difference between the two chambers, a control valve actuated by shifting operation of the input member for producing the pressure difference between the constant-pressure chamber and the variable-pressure chamber, a control member disposed, being in connection with the control valve, relatively movably to the power piston in the operation direction thereof, and a spring disposed between the control member and the power piston, whereby the elastic force variation of the spring, due to the relative shifting of the control member and the power piston while in operation, may be transferred by the control member to the control valve for regulating the operation of the control valve.