Lock mechanism for seat track slide device
Seat tracks each include a lower rail, an upper rail, a lock lever, and a handle. When a handle is operated, the lock lever is set in a locking state or an unlocking state by engaging and disengaging the lock lever with and from lock recesses in the lower rail. The lock lever is supported pivotally with respect to the upper rail by pivot support portions, in which support holes in side plates of the upper rail and protrusions on arm plates of the lock lever are fitted together. A torsion coil spring, which interlocks the handle and the lock lever, includes a second stopper, which hooks on first stoppers provided on the arm plates of the lock lever.
1. A lock mechanism for a seat track slide device, the lock mechanism comprising:
a lower rail configured to be fixed to a floor;
an upper rail configured to be fixed to a seat and supported movably relative to the lower rail;
a plurality of lock portions formed in the lower rail to be arranged in a moving direction of the upper rail;
a lock member attached to the upper rail, the lock member having lock portions, which are engaged with and disengaged from the lock portion formed in the lower rail; and
a handle extending from the lock member, wherein
the lock member is inserted in the upper rail and has a pair of arm plates arranged side by side in a direction intersecting with the moving direction of the upper rail with an interval formed in between, a support plate extending from at least one of the arm plates, the handle being connected to the support plate,
the lock member being supported pivotally with respect to the upper rail by a pivot support portion, in which a recess formed in one of the upper rail and at least one of the arm plates of the lock member is fitted on a protrusion formed on the other of the upper rail and the at least one of the arm plates of the lock member, wherein the pivot support portion, in which the recess and the protrusion are fitted together, is provided on the upper rail and the arm plates of the lock member and between the lock portions of the lock member and the handle,
the lock member and the handle are interlocked with each other by an elastic force of a spring supported between the lock member and the handle,
the lock member can be set to a locking state or an unlocking state by operating the handle to engage or disengage the lock member with or from the lock portions formed in the lower rail, wherein
each arm plate of the lock member has a first stopper,
the spring has a second stopper, which engages with the first stoppers, and
engagement between the first and second stoppers prevents the protrusion and the recess from coming off from each other in directions opposite to directions in which the protrusion and the recess are fitted together in the pivot support portion, so that the protrusion and the recess of the pivot support portion are kept fitted together, and wherein the second stopper of the spring and the first stoppers of the arm plates of the lock member are provided between the pivot support portion and the handle.
2. The lock mechanism for a seat track slide device according to claim 1 , wherein
in one of the arm plates from which the support plate extends in the lock member, the first stopper, which is continuous with the support plate, is located between the pivot support portion and the support plate and is formed adjacent to the pivot support portion, and
in the other arm plate, the first stopper, which faces the first stopper of the arm plate from which the support plate extends, extends in a cantilevered fashion and is adjacent to the pivot support portion.
3. The lock mechanism for a seat track slide device according to claim 1 , wherein
the spring is a torsion coil spring having a coil portion and a pair of arm portions extending from the coil portion,
one of the arm portions is supported by the handle, and
the other arm portion is provided with the second stopper.
4. The lock mechanism for a seat track slide device according to claim 1 , wherein the protrusion of the pivot support portion is loosely fitted in the recess and is pressed against the recess by elastic force of the spring.