Patent ID: 7708487

Claim:
A system of binder spines comprising: a first binder spine; a second binder spine; at least a third binder spine, each of said binder spines including a back panel, said back panel being generally rectangular, having a width and a length and bounded by generally opposed longitudinal edges and generally opposed lateral edges, a first of said longitudinal edges being joined through a first living hinge to a first side panel mounting edge of a first side panel and a second of said longitudinal edges being joined through a second living hinge to a second side panel mounting edge of a second side panel, each of said binder spines being foldable along said living hinges between an open generally flat configuration and a generally closed configuration, a plurality of post members located on said first side panel and a plurality of socket members located on said second side panel, said socket and post members including mating walls and being spaced apart in said open generally flat configuration by a distance, said mating walls being generally straight sided cylinders throughout their lengths, said socket and post members being positioned to retainingly interengage one another in said generally closed configuration to hold said binder spine in said generally closed configuration, said socket members being closed except for an opening at the top, each said opening being adapted to receiving a said post member in a snap fit wherein said post and socket members are adapted to forming airtight seals with one another when interengaged, the back panel in said second binder spine being at least about one-tenth of an inch wider than the back panel in said first binder spine, and the back panel in said third binder spine being at least about one-tenth of an inch wider than the back panel in said second binder spine, said distance between said socket members and post members being substantially the same in each of said first, second, and third binder spines.