Chairs and seats – Movable back – Tiltable
Reexamination Certificate
2000-05-01
2001-11-06
Barfield, Anthony D. (Department: 3636)
Chairs and seats
Movable back
Tiltable
C297S378120, C296S065170
Reexamination Certificate
active
06312055
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lock device for seatback which can hold a seatback of a vehicle seat at a predetermined angle, and which can self-lock upon upward pivoting of the seatback.
2. Description of the Prior Art
Hitherto, various types of lock devices for automotive pivotal seatback have been developed, one of which is described in Japanese Utility Model Second Publication 7-10946.
The lock device of the publication generally comprises a lock pin provided in the seatback, a spring for biasing the lock pin toward a lock position and a lock plate fixed to a side wall of a vehicle. That is, when the seatback comes to a desired angular position relative to a seat cushion, the lock pin is engaged with a lock hole of the lock plate due to the force of the spring. Upon this, the seatback is locked at the desired angular position. The lock device further comprises a self-lock mechanism by which self-locking of the lock device is carried out upon pivoting of the seatback from a forward folded position to a raised position. The self-lock mechanism comprises a guided pin fixed to the lock pin and a guide portion provided by the lock plate. Upon the upward pivoting of the seatback, the guided pin rises up and slides on the guide portion until the lock pin arrives at a position at which it engages with the lock hole. That is, until arrival of the lock pin at the position, the guided pin holds the lock pin at an unlocking position against the force of the spring, and thus upon arrival, the lock pin is moved until it engages the lock hole, enabling self-locking of the lock device.
However, since the guide portion provided by the lock plate is exposed to the vehicle compartment, the conventional lock device has an unsatisfactory external view. Furthermore, noise is produced by the sliding of the guided pin in the guide portion because the sliding is done against the force of the spring. Furthermore, when forward pivoting of the seatback is needed, the lock pin must be lifted high enough to avoid collision with the guide portion that tends to occur during the forward pivoting of the seatback. Thus, a large manipulated variable of the lock pin is needed, which causes poor operability of the lock device.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a lock device of a seatback having an improved external view due to no protrusion extending into the vehicle compartment.
It is another object of the present invention to provide such a lock device which self-locks upon upward pivoting of the seatback.
It is still another object of the present invention to provide such a lock device which has improved operability upon forward pivoting.
It is further object of the present invention to provide a measure for solving the above-mentioned drawback.
According to the present invention, there is provided a lock device which comprises a base plate fixed to a seatback having a lock pin biased by a spring. The lock pin engages a lock hole formed in a lock plate provided in a side wall of a vehicle body. The seatback is held at a predetermined angle by a lock device. A lift lever having two arm portions is held in a rest position by a force of a spring and pivotally connects to the seatback. Upon upward pivoting of the seatback, one arm portion contacts the front edge of the lock plate and pivots in a certain direction bringing about a pivoting of the other arm portion toward an unlocking position, enabling self-locking.
According to the present invention, there is further provided a lock device which comprises a lock plate having a guide slot into which one arm portion of a lifter lever enters upon upward pivoting of the seatback. The arm portion contacts an end of the guide slot upon forward pivoting of the seatback. The lifter lever reversely pivots from a rest position toward an unlocking position, and the arm portion is withdrawn from the guide slot, enabling forward pivoting of the seatback.
According to the present invention, there is further provided a lock device in which, upon upward pivoting of a seatback, a lift lever pivots and a lock pin moves toward an unlocking position, enabling self-locking. The self-locking is smoothly achieved, and there is no protrusion inside of the vehicle compartment, improving the external view.
According to the present invention, there is further provided a lock device in which, upon forward pivoting of a seatback, a lift lever reversely pivots and is withdrawn from a guide slot of a lock plate. Thus a large operating stroke of a lock pin is unnecessary, and the seatback can be easily pivoted forward, improving the operability of the lock device.
According to the present invention, there is provided a lock device of a pivotal seatback which comprises a base plate secured to the seatback; a lock pin held by the base plate, the lock pin being axially movable between locking and unlocking positions; first biasing means for biasing the lock pin toward the locking position; a lock plate secured to a fixed member, the lock plate having a plurality of lock holes with which the lock pin is engageable when assuming the locking position; a lift plate pivotally held by the base plate, the lift plate lifting the lock pin to the unlocking position when pivoted to a lift position from a rest position; a lift lever pivotally held by the base plate, the lift lever having first and second arm portions, the first arm portion being in contact with the lift plate so that when pivoted to a lift position from a rest position, the lift lever pivots the lift plate to the lift position; and second biasing means for biasing both the lift plate and the lift lever to assume their respective rest positions.
REFERENCES:
patent: 4561694 (1985-12-01), Mouri et al.
patent: 5562325 (1996-10-01), Moberg
patent: 5664839 (1997-09-01), Pedronno et al.
patent: 5713634 (1998-02-01), Koike
patent: 6132000 (2000-10-01), Tanaka
patent: 7-10946 (1995-03-01), None
Barfield Anthony D.
Foley & Lardner
Ohi Seisakusho Co. Ltd.
LandOfFree
Lock device of seatback does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lock device of seatback, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lock device of seatback will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2575421