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US 4,630,866 AGranted
Seat recline unit
AssigneeMorse Controls Limited
InventorArthur H. McFarlane
Life of this patent
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AssigneeMorse Controls Limited
InventorArthur H. McFarlane
Estimating the term…
A recline unit (6) for controlling the recline angle of the back rest (2) of a seat (1) is interposed as a strut between the back rest (2) and the seat base (3). The recline unit (6) has a recirculating ball screw (7) and nut (8) of which the former is mounted to the back rest (2) so as to be restrained against rotation and of which the latter is mounted to the seat base (3) so as to be restrained from moving axially but to be free to rotate. Manual pressure applied to the back rest (2) to incline it will move the ball screw (7) axially and cause the nut (8) to rotate. A locking mechanism (25) is provided to lock the nut (8) against rotation when the back rest (2) is in the desired reclined attitude and so prevent further axial movement of the ball screw (7). The occupant of the seat (1) can unlock the locking mechanism (25 ) by operating a button (40) which acts through a pull cable (37) on the locking mechanism (25). A back rest return device (41) includes a constant torque torsion spring (43) which, when manual pressure is removed from the back rest (2) and when the locking mechansim (25) is unlocked, will reversely rotate the nut (8) thereby to axially move the ball screw (7) reversely and so return the back rest (2) towards its upright attitude, the torsion spring (43) being strained when the nut (8) is rotated during reclining of the back rest (2).
A recline unit for the inclinable back rest of a seat, comprising a cooperating screw and nut means, mounting means for mounting the cooperating screw and nut means between the back rest and a fixed part of the seat so that the recline unit is interposed as a strut therebetween, the cooperating screw and nut means when so mounted being responsive to the back rest being inclined such that relative axial movement occurs between the cooperating screw and nut means so varying the length of the strut in accordance with the inclination of the back rest with attendant relative rotational movement between the cooperating screw and nut means, and torsion spring means strained in response to the cooperating screw and nut means making said relative rotational movement and operative to effect reverse relative rotational movement between the cooperating screw and nut means with attendant reverse relative axial movement thereof to cause opposite variation in the length of the strut and so return the back rest to a lesser inclination.
A recline unit for the inclinable back rest of a seat, comprising a cooperative screw and nut means, mounting means for mounting the cooperating screw and nut means between the back rest and a fixed part of the seat so that the recline unit is interposed as a strut therebetween, the cooperating screw and nut means when so mounted being responsive to the back rest being inclined such that relative axial movement occurs between the cooperating screw and nut means so varying the length of the strut in accordance with the inclination of the back rest with attendant relative rotational movement between the cooperating screw and nut means, and torsion spring means strained in response to the cooperating screw and nut means making said relative rotational movement between the cooperating screw and nut means with attendant reverse relative axial movement thereof to cause opposite variation in the length of the strut and so return the back rest to a lesser inclination, wherein said mounting means comprises first mounting means for mounting the screw means to one of the back rests and the fixed part of the seat and second mounting means for mounting the nut means to the other of the back rests and the fixed part of the seat, the screw means when so mounted by the first mounting means being restrained against rotation about the axis of the screw means, and the nut means when so mounted by the second mounting means being restrained against axial movement but being free to rotate about the axis of the nut means, the screw means when so mounted being responsive to the back rest being inclined to move axially in one direction relative to the nut means thereby to cause the nut means to rotate about its axis, the torsion spring means being strained in response to said rotation of the nut means and operative to effect rotation of the nut means in the opposite sense thereby to cause the screw means to move axially in the opposite direction so returning the back rest to a lesser inclination, wherein the torsion spring means is a constant torque spring and wherein the cooperating screw and nut means is a high efficiency recirculating ball screw and nut.
Dependencies are inferred from the claim text.