Portable seat and back rest

Claim 2

A portable seat and back rest assembly comprising a pair of spring-like plates hinged together to form a seat rest frame and a back rest frame, a soft foam cover on the top surface of the seat plate and on the front surface of the back rest plate, a pair of parallel tracks mounted on the back of the back rest plate, one adjacent each side edge of the plate, an adjusting slide mounted on the tracks and bearing against the back of the back rest plate and imparting a forward transverse bow in the back rest plate to provide a lumbar support, and friction means forming part of the slide and engaging the tracks to yieldably retain the slide at any selected vertical elevation on the tracks.

Claim 3

An assembly as defined in claim 1 further characterized by said plates being made of spring steel, and slots formed in the plates to increase their flexibility.

Claim 4

An assembly as defined in claim 1 further characterized by said slide including a housing mounted on each track and bearing against the back rest plate, and a horizontal flexible band connected between the housings and bearing against the back rest plate providing support for the plate between the tracks.

Claim 5

An assembly as defined in claim 3 further characterized by said tracks being spaced from the back surface of the back rest plate, and said housings being disposed between the tracks and that back surface.

Claim 6

An assembly as defined in claim 4 further characterized by said tracks being a wide, flat band, said housings being open on the side facing the track, said friction means including a spring mounted in each housing and bearing against and slidable along the track.

Claim 7

An assembly as defined in claim 4 further characterized by a plurality of recesses formed on one of the surfaces of the track and spring bearing against one another and a boss on the other of the surfaces bearing against one another for releasably retaining the housings and tracks in a set position.

Claim 8

A back rest assembly comprising a back rest plate made of a flexible material, a slide assembly mounted on the back surface of the back rest plate and movable vertically against the back surface to change the curvature of the plate and produce a horizontal ridge across it to press against the small of the back of the user of the back rest, said slide assembly including a pair of vertical tracks on the back of the back rest plate along the sides thereof and somewhat stiffer than the plate, a housing slidable up and down on each of the tracks and bearing against the back surface of the plate, and flexible band means connected to the two housings and bearing against the back surface of the plate between the housing, and means in the housings frictionally engaging the track to hold the assembly in any set vertical position on the tracks.

Claim 9

A back rest assembly comprising a back rest plate made of a flexible material, a slide assembly mounted on the back surface of the back rest plate and movable vertically against the back surface to change the curvature of the plate and produce a horizontal ridge across it to press against the small of the back of the user of the back rest, said slide assembly including a pair of vertical tracks on the back of the back rest plate along the sides thereof and somewhat stiffer than the plate, a housing slidable up and down on each of the tracks and bearing against the back surface of the plate, and flexible band means connected to the two housings and bearing against the back surface of the plate between the housing, and means in the housings frictionally engaging the track to hold the assembly in any set vertical position on the tracks.

Claim 10

An assembly as defined in claim 7 further characterized by a seat pivotally secured to the bottom of the back rest plate.

Claim 11

An assembly as defined in claim 8 further characterized by said plate being made of spring steel.

Claim 12

An assembly as defined in claim 8 further characterized by a foam sheet on the front of the back rest and on the seat, and a covering for the back rest and seat, said covering being releasably closed at the back rest to provide access to the slide assembly.

Claim 13

An assembly as defined in claim 10 further characterized by said tracks being spaced from the back surface of the back rest plate, and said housings being disposed between the tracks and that back surface.

Claim 14

An assembly as defined in claim 11 further characterized by one end of each track being slidably attached to the back of the back rest plate and the other ends of the tracks being fixed thereto.

Claim 15

An assembly as defined in claim 7 further characterized by the housings having a curved edge which bears against the back surface of the plate, the radius of curvature of the edge of the housing being approximately 2 inches.

Claim 16

An assembly as defined in claim 7 further characterized by the plate being slightly curved in a vertical direction and concave when viewed from the rear, and said housing having a curved edge which bears against the back surface of the plate, the radius of curvature of the edge being substantially less than that of the plate.