Motor-vehicle frame

1. A motor-vehicle frame, comprising:

a pair of longitudinal members comprising a first longitudinal member and a spaced apart second longitudinal member;

a plurality of cross members that extend between and join said longitudinal members to one another, said pair of longitudinal members and said plurality of cross members forming a resting surface that defines a surface of a floor;

a front-seat assembly disposed above said resting surface;

a pair of upwardly extending front uprights disposed forward of said front-seat assembly; and

a platform structure comprising:

a raised portion raised above said resting surface, said front-seat assembly being mounted on said raised portion, and

two opposite foot formations that support said raised portion and that rest on said resting surface or on at least one of said longitudinal members, a space being formed below said raised portion and between said foot formations;

at least one additional upright upwardly projecting from said first longitudinal member of said pair of longitudinal members;

a longitudinal element that is disposed at an elevation above said raised portion and that extends from said at least one additional upright to one upright of said pair of front uprights; and

said platform structure further comprising at least one lateral support that upwardly extends from said raised portion to said longitudinal element.

2. The frame according to claim 1 , wherein said platform structure comprises a further lateral support that connects said raised portion to said second longitudinal member of said pair of longitudinal members.

3. The frame according to claim 2 , wherein said further lateral support extends, for joining said raised portion to said second longitudinal member of said pair of longitudinal members, in a direction inclined downwards, towards said second longitudinal member.

4. The frame according to claim 1 , comprising a pair of further longitudinal elements that are set on the same level as or are below said pair of longitudinal members and are joined to one another by said cross members.

5. The frame according to claim 1 , wherein said platform structure is constituted by bent metal sheets or else by tubular modules.

6. The frame according to claim 1 , wherein said platform structure comprises:

a first metal sheet, which is bent substantially to form an arch and is oriented so as to define a substantially horizontal raised surface;

two transverse metal sheets, which are coupled to the opposite edges of said first metal sheet and are cut out in a central region thereof so as to reproduce the arched profile defined by said first metal sheet; and

a top metal sheet bent so as to define a substantially horizontal central portion, which constitutes said raised portion, and two inclined lateral portions, which are designed to define said lateral supports.

7. The frame according to claim 1 , wherein said structure comprises two parallel plane modules, each of which is formed by tubular portions and has at least two pillars and a horizontal element supported by said pillars, the latter connecting up to said additional longitudinal element set on top of said one longitudinal member, via an extension inclined upwards, and to said other longitudinal member via an extension inclined downwards, wherein said pillars of said modules define said foot formations, said horizontal element defines said raised portion, and said extensions define said lateral supports, and wherein said structure moreover comprises at least one cross member that connects said modules together.

8. The frame according to claim 1 , wherein said platform structure is configured for performing a function of support for the door of said motor vehicle.

9. The frame according to claim 8 , wherein said structure comprises a further lateral support, configured for constituting an upright designed to withstand the lateral loads acting against said door.

10. The frame according to claim 1 , wherein said longitudinal element is disposed at an elevation below an upper end of said front-seat assembly.

11. The frame according to claim 1 , wherein said longitudinal element connects with said at least one additional upright at an elevation above said raised portion.

12. The frame according to claim 1 , wherein said longitudinal element connects with said one upright of said pair of front uprights at an elevation above said raised portion.

13. The frame according to claim 1 , wherein said first longitudinal member and said second longitudinal member each have a first end and an opposing second end, the raised portion being disposed between said first end and said second end of said first longitudinal member and said second longitudinal member.

14. The frame according to claim 1 , further comprising a rear-seat assembly disposed behind the front-seat assembly.