Sleep system mechanism

A sleep system assembly adapted for conversion between a sofa configuration where a user may sit on said assembly in a substantially upright position, and a sleep configuration, where said user may lie in a substantially prone position, said assembly comprising:

• a supporting frame;
• a seat having an upper surface on which said user may sit when said assembly is in said sofa configuration;
• a back cushion assembly having a frontal region for supporting said user's back when said assembly is in said sofa configuration;
• at least one linkage mechanism, said linkage mechanism being directly or indirectly connected to said frame, and coupled to said back cushion assembly, said linkage mechanism guiding movement of said back cushion assembly between said sofa configuration and said sleep configuration in response to external forces applied by said user to said sleep system assembly;
• when said sleep system assembly is in said sleep configuration, a sleep surface is formed by rear surface regions of said back cushion assembly, and said back cushion assembly is supported and prevented from further downward movement by elements of said sleep system assembly located only below said rear surface regions of said back cushion assembly;
• and
• said linkage mechanism is configured and coupled to said back cushion assembly so that movement of said sleep system assembly between said sofa configuration and said sleep configuration requires said user to only apply said external forces at a single location of said sleep system assembly.