Abstract: A recliner has a ratchet and a guide assembled together so as to be rotatable relative to each other, and a pawl supported by the guide in its circumferential direction. The pawl has an outer tooth row adapted to mesh with a part of an inner tooth row of the ratchet so as to inhibit rotational movement of the ratchet relative to the guide. The outer tooth row of the pawl is meshed with the inner tooth row of the ratchet such that only two adjacent tooth flanks located in a center of the outer tooth row in the circumferential direction are in contact with the inner tooth row, and at least one of adjacent two tooth flanks of the outer tooth row located at positions other than the center in the circumferential direction is received in the inner tooth row without being in contact with the inner tooth row.

Abstract: A recliner has a ratchet and a guide assembled together so as to be rotatable relative to each other, and a pawl supported by the guide in a circumferential direction. The pawl is adapted to inhibit rotational movement of the ratchet relative to the guide when moved to be pushed radially outwards. The pawl is supported by guide walls formed in the guide, and the guide walls are located at circumferentially opposite sides of the pawl. Each guide wall has a recessed part (weak portion) formed at a location spaced in the circumferential direction apart from a contact face of the guide wall which is in contact with the pawl. The recessed part is adapted to undergo local stress concentration and plastic deformation due to pressing force received from the pawl when a large load that causes the pawl to undergo forced deformation in the circumferential direction is applied.

Abstract: A recliner has a ratchet and a guide assembled together so as to be rotatable relative to each other, and a pawl supported by the guide in a circumferential direction. The pawl is adapted to inhibit rotational movement of the ratchet relative to the guide when moved to be pushed radially outwards. The pawl is supported by guide walls formed in the guide, and the guide walls are located at circumferentially opposite sides of the pawl. Each guide wall has a recessed part (weak portion) formed at a location spaced in the circumferential direction apart from a contact face of the guide wall which is in contact with the pawl. The recessed part is adapted to undergo local stress concentration and plastic deformation due to pressing force received from the pawl when a large load that causes the pawl to undergo forced deformation in the circumferential direction is applied.

Abstract: A recliner has a ratchet and a guide assembled together so as to be rotatable relative to each other, and a pawl supported by the guide in its circumferential direction. The pawl has an outer tooth row adapted to mesh with a part of an inner tooth row of the ratchet so as to inhibit rotational movement of the ratchet relative to the guide. The outer tooth row of the pawl is meshed with the inner tooth row of the ratchet such that only two adjacent tooth flanks located in a center of the outer tooth row in the circumferential direction are in contact with the inner tooth row, and at least one of adjacent two tooth flanks of the outer tooth row located at positions other than the center in the circumferential direction is received in the inner tooth row without being in contact with the inner tooth row.

Abstract: A pivotal device of a vehicle seat includes ratchet and guide mounted together to be rotatable relative to each other, and pawls supported by the guide in its circumferential direction and having external teeth adapted to mesh with internal teeth of the ratchet when an operating cam pushes the pawls radially outward, so as to inhibit relative rotation of the ratchet and the guide. One of the pawls is divided obliquely into two parts in the circumferential direction, and is pushed radially outward to mesh with the ratchet while increasing its width and eliminating clearances between the pawl and the guide. The rotating cam rides on a protrusion formed on the guide during rotation thereof, so as to largely push the pawls and press the ratchet radially against the guide.

Abstract: A connecting apparatus of the present invention includes an inner teeth member with inner teeth, a guide member with a rotation support portion rotatably supporting an outer peripheral surface of the inner teeth member, a first and second teeth member movably mounted on the guide member, and a switching member capable of switching a lock state and an unlock state by moving the first and second outer teeth members. Further the connecting apparatus includes a backlash preventing mechanism capable of preventing a backlash of the inner teeth member with respect to the guide member by the switching member pushing the inner teeth member (6) to the rotation support portion of the guide member. Space is formed between outer teeth of the second outer teeth member and the inner teeth of the inner teeth member. The space permits them to mesh with each other, and forms clearance between them in a radial direction.

Abstract: A pivotal device of a vehicle seat includes ratchet and guide mounted together to be rotatable relative to each other, and pawls supported by the guide in its circumferential direction and having external teeth adapted to mesh with internal teeth of the ratchet when an operating cam pushes the pawls radially outward, so as to inhibit relative rotation of the ratchet and the guide. One of the pawls is divided obliquely into two parts in the circumferential direction, and is pushed radially outward to mesh with the ratchet while increasing its width and eliminating clearances between the pawl and the guide. The rotating cam rides on a protrusion formed on the guide during rotation thereof, so as to largely push the pawls and press the ratchet radially against the guide.

Abstract: A connecting apparatus of the present invention includes an inner teeth member with inner teeth, a guide member with a rotation support portion rotatably supporting an outer peripheral surface of the inner teeth member, a first and second teeth member movably mounted on the guide member, and a switching member capable of switching a lock state and an unlock state by moving the first and second outer teeth members. Further the connecting apparatus includes a backlash preventing mechanism capable of preventing a backlash of the inner teeth member with respect to the guide member by the switching member pushing the inner teeth member (6) to the rotation support portion of the guide member. Space is formed between outer teeth of the second outer teeth member and the inner teeth of the inner teeth member. The space permits them to mesh with each other, and forms clearance between them in a radial direction.

Abstract: A reclining device of a vehicle seat including a ratchet, a guide, three pawls and a rotating cam. Three spacing distances are defined due to such positioning of the three pawls, and one of the spacing distances is determined so as to be greater than the remaining two spacing distances. A non-toothed raised flat portion is formed in a portion of an inner circumferential surface of an inner toothed portion of the ratchet at a single site in a circumferential direction thereof. The raised flat portion is protruded radially inwardly beyond tips of inner teeth. The smaller remaining two spacing distances are determined so as to be smaller than a circumferential length of the raised flat portion.

Abstract: A reclining device of a vehicle seat including a ratchet, a guide, three pawls and a rotating cam. Three spacing distances are defined due to such positioning of the three pawls, and one of the spacing distances is determined so as to be greater than the remaining two spacing distances. A non-toothed raised flat portion is formed in a portion of an inner circumferential surface of an inner toothed portion of the ratchet at a single site in a circumferential direction thereof. The raised flat portion is protruded radially inwardly beyond tips of inner teeth. The smaller remaining two spacing distances are determined so as to be smaller than a circumferential length of the raised flat portion.