Loose-leaf binder having flexible spine

A loose-leaf binder comprising:

• a generally rectangular and relatively stiff rear cover provided with a free side margin and an inner side margin disposed opposite said free side margin;
• elongated sheet retaining means mounted on said rear cover adjacent to and parallel to said inner side margin;
• a rounded, flexible spine joined to the inner side margin of said rear cover along an outwardly bent fold line and extending therefrom along an arc which substantially encompasses said sheet binding means;
• and
• a generally rectangular and relatively stiff front cover provided with an inner side margin and a free side margin disposed opposite said inner side margin of said front cover, said front cover being joined to said spine along a reversely bent fold line so that said front cover remains substantially parallel to said rear cover as sheet stacks of different thickness are retained by said retaining means, said front cover further having a width between said side margins thereof such that said free side margin of said front cover is in general alignment with the free side margin of said rear cover.

A binder comprising:

• a generally rectangular rear cover panel having a free side margin and an inner side margin disposed opposite said free side margin, said rear cover panel having a width between said side margins thereof;
• sheet retaining mens for releasably holding sheets, said retaining means being mounted on said rear cover panel adjacent to said inner side margin and extending along said inner side margin, said retaining means having a transverse dimension along said width of said rear cover panel;
• a generally rectangular front cover panel having an inner side margin and a free side margin disposed opposite said inner side margin of said front cover panel, said inner side margin of said front cover panel being disposed parallel to said inner side margin of said rear cover panel, said front cover panel having a width between said inner and free side margins thereof, said front cover panel being less in width than said rear cover panel, the difference in width between said front and rear cover panels being greater than said transverse dimension of said sheet retaining means;
• and
• a spine sheet extending between and foldably joined along fold lines to said inner side margins of said front and rear cover panels, said spine sheet having a width between said inner side margins, said width of said spine sheet being greater that the difference in width between said front and rear cover panels.