Vehicle seat mounting devices

A vehicle seat mounting device comprising two frames (11, 12), means mounting said frames one above the other for connection to the floor of a vehicle and to the underside of a vehicle seat, said mounting means comprising spaced-apart guide rails (11a, 11b) on one of said frames (11) and rollers (17) on the other frame (12), said rollers engaging in the guide rails (11a, 11b) to permit relative sliding movement between the two frames, a third or intermediate frame (13), a position-adjusting device (15) including means for selectively connecting said intermediate frame (13) to a first one of the frames (11) and spring means (21) interposed between the intermediate frame (13) and the second frame (12), to allow a predetermined amount of relative movement therebetween, the position-adjusting device including a first actuator (24b, 24a) movable into and out of an engaged-state in which it locks the position-adjusting device (15) in any one of a plurality of selected static positions of the first frame (11) relative to the intermediate frame (13), lock-out means (16) including a second actuator (40h) movable into and out of an engaged state in which it causes the lock-out means (16) to lock the intermediate frame (13) to the second frame (12) thereby rendering the spring means (21) inoperative, characterised by a common operating member (27 or 127) and coupling means (25b, 34, 35) connecting the operating member (27) to said first actuator (24b or 124b) and to said second actuator (40h or 140b) and movable between a first mode `A` in which the first actuator (24b) is in its engaged state and the second actuator (40h) is in its disengaged state so that the first and third frames (11, 13 or 111, 113) are secured together but movable relative to the second frame (12 or 112) under the restraint of the spring means (21 or 121), a second mode `B` in which both first and second actuators are in their engaged state so that relative movement between the first, second and third frames is prevented, and a third mode `C` in which the first actuator is in its disengaged state and the first frame is movable relative to the second and third frames to change their selected relative positions.