Seat reclining device and seat device

A vehicle seat device comprising a seat back, a locking mechanism, a seat sliding device, and a switch limit mechanism, wherein

• the seat back has a tilting range divided into a seating region, in which an inclination angle thereof is adjusted, and a forward folding region set forward of the seating region,
• the seat back is tilted within the tilting range around an operation shaft relative to the seat cushion,
• when a first operation lever or a second operation lever is operated to rotate the operation shaft, the locking mechanism switches the seat back between a locked state, in which the seat back is restricted from tilting relative to the seat cushion, and an unlocked state, in which the seat back is allowed to tilt,
• the seat cushion is restricted from sliding at least in the seating region,
• the restriction of the sliding movement of the seat cushion is canceled in coordination with a tilting movement of the seat back from the seating region into the forward folding region after being unlocked by the locking mechanism, upon the second operation lever being operated,
• during operation of the first operation lever, the switch limit mechanism allows switching between locking and unlocking of the seat back by the locking mechanism only when the seat back is tilted within the seating region,
• the locking mechanism includes a first member, a second member, and a plurality of locking members,
• the first member is attached to one of the seat cushion and the seat back and has an internal gear around the operation shaft,
• the second member is attached to the other one of the seat cushion and the seat back and rotational around the operation shaft relative to the first member,
• the locking members are each attached to the second member and have external teeth facing the internal gear,
• the seat back is locked when the locking members are each pressed radially outward so that the external teeth mesh with the internal gear,
• the seat back is unlocked when the operation shaft is rotated thereby to move each of the locking members radially inward so that the external teeth disengage from the internal gear,
• the vehicle seat device further comprises a memory mechanism that remembers an angular position of the seat back where it is located immediately before being unlocked,
• the seat back, once unlocked, is locked only when it is tilted to the angular position that has been remembered,
• the memory mechanism works when the second operation lever is operated to rotate the operation shaft,
• the memory mechanism includes a housing recess, a memory plate, and an engagement portion,
• the housing recess is formed in a cylindrical shape in the first member,
• the memory plate is formed in an annular shape that is cut at one point,
• the memory plate is housed in the housing recess while being reduced in diameter,
• the memory plate includes a pair of engagement receiving portions at different positions,
• the engagement portion is provided to each of a pair of locking members, and engages with and disengages from the engagement receiving portions as the locking members move in the radial direction, and
• the unlocked state includes:
• an unlocked state in which the engagement receiving portions are pressed circumferentially with the engagement portions half engaged with the engagement receiving portions and the memory plate rotates together with the locking members relative to the housing recess, so that the seat back is allowed to tilt without the angular position being remembered;
• and
• an unlocked state in which the engagement portion going over the engagement receiving portion and slides on an inner circumferential surface of the memory plate with the memory plate being made irrotational relative to the housing recess, so that the seat back is allowed to tilt with the angular position being stored,
• the switch limit mechanism includes a rotation restricting portion provided in the first member,
• the rotation restricting portion has an inner circumferential surface with the same diameter as that of the inner circumferential surface of the memory plate on which the engagement portion slides,
• when the first operation lever is operated, the engagement portion that is half engaged is abutted on the rotation restricting portion so that the memory plate and the locking members are restricted from rotating, whereby the seat back is stopped from tilting from the seating region into the forward folding region, and
• when the second operation lever is operated, the engagement portion rides over the engagement receiving portion and the rotation restricting portion and slides on the inner circumferential surface of the memory plate, whereby the seat back is allowed to tilt from the seating region into the forward folding region.

A vehicle seat device comprising a seat back, a locking mechanism, a seat sliding device, and a switch limit mechanism, wherein

• the seat back has a tilting range divided into a seating region, in which an inclination angle thereof is adjusted, and a forward folding region set forward of the seating region,
• the seat back is tilted within the tilting range around an operation shaft relative to the seat cushion,
• when a first operation lever or a second operation lever is operated to rotate the operation shaft, the locking mechanism switches the seat back between a locked state, in which the seat back is restricted from tilting relative to the seat cushion, and an unlocked state, in which the seat back is allowed to tilt,
• the seat cushion is restricted from sliding at least in the seating region,
• the restriction of the sliding movement of the seat cushion is canceled in coordination with a tilting movement of the seat back from the seating region into the forward folding region after being unlocked by the locking mechanism, upon the second operation lever being operated,
• during operation of the first operation lever, the switch limit mechanism allows switching between locking and unlocking of the seat back by the locking mechanism only when the seat back is tilted within the seating region,
• the locking mechanism includes a first member, a second member, and a plurality of locking members,
• the first member is attached to one of the seat cushion and the seat back and has an internal gear around the operation shaft,
• the second member is attached to the other one of the seat cushion and the seat back and rotational around the operation shaft relative to the first member,
• the locking members are each attached to the second member and have external teeth facing the internal gear,
• the seat back is locked when the locking members are each pressed radially outward so that the external teeth mesh with the internal gear,
• the seat back is unlocked when the operation shaft is rotated thereby to move each of the locking members radially inward so that the external teeth disengage from the internal gear,
• the vehicle seat device further comprises a memory mechanism that remembers an angular position of the seat back where it is located immediately before being unlocked,
• the seat back, once unlocked, is locked only when it is tilted to the angular position that has been remembered,
• the memory mechanism works when the second operation lever is operated to rotate the operation shaft,
• the memory mechanism includes a housing recess, a memory plate, and an engagement portion,
• the housing recess is formed in a cylindrical shape in the first member,
• the memory plate is formed in an annular shape that is cut at one point,
• the memory plate is housed in the housing recess while being reduced in diameter,
• the memory plate includes a pair of engagement receiving portions at different positions,
• the engagement portion is provided to each of a pair of locking members, and engages with and disengages from the engagement receiving portions as the locking members move in the radial direction, and
• the unlocked state includes:
• an unlocked state in which the engagement receiving portions are pressed circumferentially with the engagement portions half engaged with the engagement receiving portions and the memory plate rotates together with the locking members relative to the housing recess, so that the seat back is allowed to tilt without the angular position being remembered;
• and
• an unlocked state in which the engagement portion going over the engagement receiving portion and slides on an inner circumferential surface of the memory plate with the memory plate being made irrotational relative to the housing recess, so that the seat back is allowed to tilt with the angular position being stored,
• the switch limit mechanism includes:
• an abutment receiving portion that is provided to the seat back and is displaced with a tilting movement of the seat back;
• a movable stopper tiltably supported by a shaft to tilt between an abutting position, where the movable stopper is abutted on the abutment receiving portion to restrict tilting of the seat back, and a non-abutting position, where the movable stopper is retracted from the abutting position;
• a link member that is connected to the operation shaft and capable of transmitting, to the movable stopper, rotation of the operation shaft upon the first operation lever or the second operation lever being operated;
• and
• rotation transmission control means, wherein
• the rotation transmission control means
• does not transmit rotating movement of the link member to the movable stopper when the first operation lever or the second operation lever is operated in order to rotate the operation shaft by an angle for unlocking and allowing the seat back to tilt without an angular position being remembered;
• positions the movable stopper at the abutting position to restrict the seat back from being tilted forward, whereby switching between the locked and unlocked states by the locking mechanism is allowed to be performed only when the seat back is tilted within the seating region;
• transmits rotating movement of the link member to the movable stopper when the second operation lever is operated more largely to rotate the operation shaft than when unlocking and allowing the seat back to tilt without an angular position being remembered;
• and
• retracts the movable stopper to the non-abutting position to cancel the restriction of the forward tilting of the seat back, whereby the seat back is allowed to tilt from the seating region into the forward folding region.