Vehicle seat

1. A vehicle seat base comprising a generally concave seat pan and side plates bonded to the seat pan for mounting the seat pan to the vehicle wherein the seat pan is formed of a composite material and has, relative to the direction of movement of the vehicle, a front face, a rear face, two lateral side faces and a bottom face, and wherein the side plates extend from the front towards the rear of the seat pan and the bond extends along at least part of the length of each of the side plates and wherein the front face, rear face and two lateral side faces all extend generally downwardly towards a bottom face, the front, rear and lateral side faces being at least in part planar and at least in part tapering inwardly and being configured when in use to receive and support together with the bottom face at least a part of the buttocks or the thighs of a person sitting on the seat, the upper edges of the front, rear and lateral side faces together defining a circumferential lip of the seat pan which extends around the circumference of the seat pan.

2. The vehicle seat base according to claim 1 , wherein each side plate includes at least one fixture for a pivoting link of a height adjust mechanism, and wherein the rear, front and side faces extend so that in use substantially all of the circumferential lip is vertically above the fixtures and the bottom face is vertically below the fixtures.

3. The vehicle seat base according to claim 2 comprising the height adjust mechanism mounted to the at least one fixture and further mountable directly or indirectly to the vehicle, for selectively adjusting the height of the seat base relative to the vehicle, the height adjust mechanism comprising a four link pivoting mechanism arranged to swing the seat base between first and second positions, the first position being forwards and lower relative to the second position.

4. The vehicle seat base according to claim 1 , wherein there are fixtures on each side plate for mounting the side plates directly or indirectly to the vehicle and located forwardly of and the same distance from the rear face of the seat pan, and between the rear face of the seat pan and the front face of the seat pan, and wherein the space within the seat pan extending directly between the said fixtures is in use substantially unobstructed by any seat structure.

5. The vehicle seat base according to claim 1 , wherein the side plates are bonded to the seat pan along at least 50% of their length.

6. The vehicle seat base according to claim 1 , wherein the seat pan is a unitary item.

7. The vehicle seat base according to claim 1 , wherein the thickness of the rear, front and side faces is greater than the thickness of the bottom face.

8. The vehicle seat base according to claim 1 , wherein there are apertures formed in the bottom face.

9. The vehicle seat base according to claim 1 comprising cushioning material within the seat pan, covering the front, rear, side and bottom faces.

10. The vehicle seat base according to claim 1 comprising a mechanism mounted to the side plates for mounting directly or indirectly to the vehicle for selectively adjusting the height of the seat base relative to the vehicle.

11. The vehicle seat base according to claim 10 , wherein the mechanism comprises a four link pivoting mechanism arranged to swing the seat base between first and second positions, the first position being forwards and lower relative to the second position.

12. The vehicle seat base according to claim 11 , wherein the four link mechanism is pivotally mounted to two fixtures along the side plates, one towards the front and a second toward the rear of the side plate, wherein the second fixture is forward of the rear face of the seat pan, and wherein the space within the seat pan extending directly between the said fixtures is substantially unobstructed by any seat structure.

13. The vehicle seat base according to claim 1 , wherein the seat pan comprises a first layer, a second, core layer and a third layer.

14. The vehicle seat base according to claim 1 , wherein the side plates are adapted to provide mounting points for a seat back.