Vehicle seats

Claim 2

A vehicle seat comprising a base part, a seat part mounted on a spring suspension for upward and downward movement relative to said base part, said spring suspension comprising a gas spring, a pump source of compressed gas forming part of the seat and fixed to said base part, said pump being permanently connected to the said gas spring and operable to introduce gas into said spring in order to raise the level of said seat part to a ride position, and a valve connected to said gas spring operable to release gas from said spring in order to lower the level of the seat part to the ride position, said pump source comprising a cylinder mounted for pivotal movement about an axis perpendicular to the axis of the cylinder, a piston positioned in said cylinder, a piston rod having an outer end extending from said piston, a linkage arm having opposite ends pivoted at one end to the outer end of the piston rod at a pivot connection and at its opposite end about a support on the base part, and means for moving said linkage arm about said support thereby to move the piston relative to the cylinder.

Claim 3

A vehicle seat according to claim 1 wherein the means for moving the linkage arm of the pump comprises a handle movable angularly about said support and rigidly connected to said linkage arm.

Claim 4

A vehicle seat according to claim 1 wherein the pivot connection between the piston rod and linkage arm is movable along a linear path through a position in which said rod and arm are colinear.

Claim 5

A vehicle seat according to claim 3 wherein said linear path is generally vertical and the means for moving the linkage arm of the pump comprises a mass free to move vertically in response to upward and downward movement of the vehicle and connected to the pump in the vicinity of the pivot connection.

Claim 6

A vehicle seat comprising a base part, a seat part mounted on a spring suspension for upward and downward movement relative to said base part, said base part comprising a base plate fixable to the floor of the vehicle, a column extending upwardly at the rear of said seat part from said base plate, and said spring suspension comprising guides attached to said column, a carriage connected to the seat part and mounted in said guides for movement up and down the column, a suspension arm having opposite ends pivoted at one end to the base part and at its opposite end to the seat part, a spring opposing the downward movement of the carriage, and a shock absorber connected between the carriage and the base part, said spring being in the form of a gas spring comprising first and second gas chambers, said first gas chamber being mounted on said base part and in communication with said second gas chamber mounted on said carriage, one of said first and second chambers having a constant volume and the other of said first and second chambers being flexible to permit expansion and contraction of the space within the flexible chamber in response to upward and downward movement of the seat part, the gas spring having an inlet valve for introducing compressed gas into the chambers and an outlet valve for releasing compressed gas from the chambers to raise or lower, respectively, the seat part.

Claim 7

A vehicle seat comprising a base part, a seat part mounted on a spring suspension for upward and downward movement relative to said base part, said base part comprising a base plate fixable to the floor of the vehicle, a column extending upwardly at the rear of said seat part from said base plate, and said spring suspension comprising guides attached to said column, a carriage connected to the seat part and mounted in said guides for movement up and down the column, a suspension arm having opposite ends pivoted at one end to the base part and at its opposite end to the seat part, a spring opposing the downward movement of the carriage, and a shock absorber connected between the carriage and the base part, said spring being in the form of a gas spring comprising first and second gas chambers, said first gas chamber being mounted on said base part and in communication with said second gas chamber mounted on said carriage, one of said first and second chambers having a constant volume and the other of said first and second chambers being flexible to permit expansion and contraction of the space within the flexible chamber in response to upward and downward movement of the seat part, the gas spring having an inlet valve for introducing compressed gas into the chambers and an outlet valve for releasing compressed gas from the chambers to raise or lower, respectively, the seat part.

Claim 8

A vehicle seat according to claim 5 further comprising pump means mounted on the base part and having a gas-flow connection to said inlet valve.

Claim 9

A vehicle seat according to claim 5 wherein the flexible chamber comprises a bellows connected at one end to an inlet of the constant volume chamber and at its opposite end to a mounting hub fixed on the base part.

Claim 10

A vehicle seat according to cLaim 7 wherein the bellows is of a rolling-lobe type.

Claim 11

A vehicle seat according to claim 5 wherein the column is of generally rectangular section but having an elongate opening extending upwardly along one side, and the carriage supports rollers which roll in said guides.

Claim 12

A vehicle seat according to claim 5 wherein said inlet valve is connected to an inertia pump means operable in response to upward and downward movement of the base part of the seat.

Claim 13

A vehicle seat according to claim 10 including a leveling valve means operable to connect the spring to atmosphere when the seat part remains above the ride position, and to connect the spring to the pump when the seat part remains below the ride position.