Reclining device

A reclining device for a seat, which includes an upper arm adapted to be fixed to a seat back of the seat and a lower arm adapted to be fixed to a seat cushion of the seat, said upper arm being rotatable with respect to said lower arm, said upper arm having a gear section at a lower end thereof, said reclining device comprising:

• a lock gear means rotatable downward or upward on said lower arm to respectively permit meshed engagement or disengagement from said gear section said lock gear means having a contact edge defined at a lower side thereof;
• a cam means rotatablg mounted on said lower arm adjacent to said lock gear means,
• said cam means having a first center of rotation defined therein, and a first end portion and a second end portion, wherein said second end portion includes at least two different cam surfaces, each having a contact area upon which said contact edge of said lock gear means can be stably engaged;
• said at least two different cam surfaces including a first cam surfaces spaced from said first center of rotation which rotates said lock gear means upwardly for the meshed engagement with said gear section and a second cam surface spaced from said first center of rotation to permit said iock gear means to be rotated downwardly for disengagement from said gear section;
• an operation lever means rotatably provided on said lower arm, said operation lever means having a second center of rotation, a generally rectilinear section defined at a first end thereof and a downwardly expanding section defined at a second end thereof opposite to said first end, such that the second center of rotation is defined between said generally rectilinear section and said downwardly expanding section and is spaced from said first center of rotation;
• said downwardly expanding section substantially overlapping said cam means;
• and connecting means on said downwardly expanding section and said cam means for slidable and continuous engagement between said operation lever means and said cam means to rotate said cam means into meshed engagement or disengagement, whereby rotation of the operation lever means causes said lock gear means to be rotated upwardly and downwardly by rotation of said cam means so as to effect meshed engagement or disengagement between said lock gear means and said gear section;
• wherein the reclining device is of a dual type comprising a pair of first and second reclining devices, each being mounted to the respective lateral sides of said seat back, wherein both said first and second devices are basically of a same structure including said lock gear means, said cam means and said connecting means, except that only one of said first and second reclining devices includes said operation lever means, wherein in addition thereto, said first and second reclining device each includes a guide means for assisting in downward rotation of said lock gear means for the disengagement from said gear section of the upper arm, wherein said guide means in said one of said first and second reclining devices is provided between said downwardly expanding section of said operation lever means and lock gear means, while said guide means in another of said first and second reclining devices is provided only at said lock gear means, and wherein an interlocking means is provided between said first and second reclining devices in order to cause said cam means and guide means to be actuated simultaneously in both said first and second reclining devices only through said one operation lever means, to thereby effect the meshed engagement and disengagement of said lock gear means with and from said gear section in both of said first and second reclining devices.

A reclining device for a seat, which includes an upper arm adapted to be fixed to a seat back of the seat and a lower arm adapted to be fixed to a seat cushion of the seat, said upper arm being rotatable with respect to said lower arm, said upper arm having a gear section at a lower end thereof, said reclining device comprising:

• a lock gear means rotatable downward or upward on said lower arm to respectively permit meshed engagement with or disengagement from said gear section associated with said upper arm, said lock gear means having a contact edge defined at the lower side thereof;
• a cam means rotatable mounted on said lower arm, adjacent to said lock gear means, said cam means having a first center of rotation defined therein, first end portion and second end portion, wherein said second end portion includes at least two different cam surfaces, each having a contact area upon which said contact edge of said lock gear means can be stably engaged;
• said at least two different cam surfaces including a first cam surface spaced from said first center of rotation which rotates said lock gear means upwardly for meshed engagement with said gear section and second cam surface spaced from said first center of rotation to permit said lock gear means to be rotated downwardly for disengagement from said gear section;
• an operation lever means rotatably provided at said lower arm, said operation lever means having a second center of rotation, a generally rectilinear section and a downwardly expanding section, such that the second center of rotation is defined between said generally rectilinear and downwardly expanding section and further spaced from said first center of rotation on said cam means;
• said downwardly expanding section substantially overlapping said cam means;
• and
• said cam means being of smaller area than that of said downwardly expanding section of said operation lever means and interposed between said lower arm and said downwardly expanding section such that the cam means is substantially rotatable within the area of the downwardly expanding section;
• said contact edge of said lock gear means being disposed within the area of said downwardly expanding section of said operation lever means, such that the contact edge may be contacted upon a selected one of said first cam surface and said second cam surface within the area of said downwardly expanding section;
• and
• a connecting means for operatively and directly connecting said downwardly expanding section of said operation lever means with said first end portion of said cam means;
• said connecting means being formed in both said downwardly expanding section and said first end portion of said cam means;
• wherein a pin is provided at said lower arm, which corresponds to said center of rotation of said cam means, whereupon said cam means is rotatable on said pin, wherein said pin extends in a direction transversal of both said upper arm and said downwardly expanding section of said operation lever means, and wherein an escapement hole means is defined in said downwardly expanding section such as to allow said pin to move freely therein without interference with said operation lever means.