Lock mechanism for adjustable seat

A seat support mechanism for supporting a seat so that the position of the seat is adjustable back and forth, comprising:

• first and second parallel guide rails,
• first slide means slidable on said first guide rail in forward and backward directions, and second slide means slidable on said second guide rail in the forward and backward directions, said first and second slide means being adapted to support the seat under the seat so that the seat is slidable along said first and second guide rails in the forward and backward directions,
• first lock means which locks said first slide means so that said first slide means is not slidable relative to said first guide rail when said first lock means is in a lock position, and unlocks said first slide means so that said first slide means is slidable relative to said first guide rail when said first lock means is in an unlock position,
• second lock means which locks said second slide means so that said slide means is not slidable relative to said second guide rail when said second lock means is in a lock position, and unlocks said second slide means so that said second slide means is slidable relative to said second guide rail when said second lock means is in an unlock position,
• an operating bar extending from a rear end to a front end in the forward direction, said rear end of said operating bar being connected with said first lock means so that said first lock means can be moved to the unlock position with said operating bar, and
• motion transmitting means, connected between said operating bar and said second lock means, for transmitting motion from said operating bar to said second lock means so that said second lock means is moved to the unlock position together with said first lock means with said operating bar, said motion transmitting means comprising a wire extending along a line crossing said first and second guide rails, and having a first end connected with said operating bar at an intermediate position between said front and rear ends of said operating bar, and a second end, and link means extending along the longitudinal line of said second guide rail and having a front end connected with said second end of said wire, and a rear end located away from said front end of said link means in the backward direction and connected with said second lock means.