An aircraft seat has a chassis ( 21 ), fixed to a pallet which is fixed to the floor of the aircraft. The chassis has two load bearing sides ( 23 ) and opposite ends ( 24, 25 ). Fixed along the top edge of the sides ( 23 ) and facing outwards are pins ( 26 ) supporting bearing wheels ( 27 ). These on each side engage with a rectangular S form interconnection beam ( 28 ) having an inside groove ( 29 ) for receiving these wheels. On the outside, the beam has another groove ( 30 ) receiving similar wheels ( 31 ), on pins ( 32 ) fixed to the inside of side plates ( 41 ) of a sub-frame ( 42 ), these side plates being interconnected by front and rear beams ( 43, 44 ). Thus the sub-frame can move back and forth, with the wheels acting as rolling element bearings. The beams move half the distance of the sub-frame, in analogous manner to the bearing of filing cabinet drawers.
1. An aircraft seat convertible to a bed comprising:
a seat having:
a squab and a backrest, both being movable and
a mechanism for moving the squab and the backrest, the mechanism having:
a seat chassis, via which the seat can be fixed to a floor,
a first linear runner beam mounted on the seat chassis,
a seat frame sub-frame bearingly mounted on the first linear runner beam,
linear drive means for extending and retracting the sub-frame on the first linear runner beam with respect to the seat chassis between a retracted position and an extended bed position,
a pan for the squab pivotally mounted on the sub-frame,
pan angle drive means for pivoting the pan between a back dropped TTL position and a bed position,
a support for the back rest hinged to the pan and
back drive means for moving the back rest support between a back up TTL position and a bed position.
2. An aircraft seat as claimed in claim 1 , wherein the first linear runner beam (a) is mounted via roiling element bearings on the seat chassis, (b) has an S cross-section, and (c) comprises first and second grooves, with some of the rolling element hearings attached to the seat chassis engaging in the first groove of the first linear runner beam and the other of the rolling element hearings engaging in the second groove of the first linear runner beam.
3. An aircraft seat as claimed in claim 1 , wherein the linear drive means comprises a lead screw.
4. An aircraft seat as claimed in claim 1 , further comprising a second linear runner beam, and wherein the linear drive means is a pair of belts, one of the pair of belts being associated with the first linear runner beam and the other of the pair of belts being associated with the second linear runner beam, the two belts being drivable in tandem.
5. An aircraft seat as claimed in claim 4 , including:
sub-frame drive belts arranged at both sides of the seat chassis;
guide pulleys at opposite ends of the seat chassis for guiding the drive belts;
drive pulleys engaging the drive belts in one run of the belts between the guide pulleys;
a drive motor mounted on the seat chassis and drivingly connected to the drive pulleys;
pinch pulleys for normally engaging the belts with the drive pulleys;
means for manual disengagement of pinch wheels to allow the drive belts to move past the drive pulleys and
means for securing another run of the drive belts to the sub-frame.
6. An aircraft seat as claimed in claim 1 , wherein the sub-frame has a front and the pan is pivoted to the sub-frame at a position spaced back in the seat from the front of the sub-frame.
7. An aircraft seat as claimed in claim 1 , wherein the sub-frame has a front and the pan is pivoted to the sub-frame at the front of the sub-frame.
8. An aircraft seat as claimed in claim 1 , wherein the pan angle drive means comprises a crank depending below the pan and an actuator for moving a lower end of the crank back and forth.
9. An aircraft seat as claimed in claim 1 , wherein the pan angle drive means comprises a depending link, pivoted to the pan and guided at its lower end in a cam groove, along which it is driven by a lead screw, having a drive nut pivotally mounted to the sub-frame.
10. An aircraft seat as claimed in claim 1 , wherein the back rest support is hinged to the sub-frame.
11. An aircraft seat as claimed in claim 10 , wherein the hinge is a multi-link linkage providing a pivot axis spaced below the links themselves.
12. An aircraft seat as claimed in claim 1 , wherein the back drive means is an arm extending back and below the support for the back rest, and is connected at its distal end to a lead screw actuator.
13. An aircraft seat as claimed in claim 1 further comprising a second linear runner beam and in which the seat chassis defines opposed first and second sides, the first linear runner beam is mounted via rolling element bearings on the first side of the seat chassis, the second linear runner beam is mounted via rolling element bearings on the second side of the seat chassis, and the seat frame sub-frame is mounted via rolling element bearings on at least the first linear runner beam.