Location of card frame guide members

An assembly of guide members and support members for a frame construction of the type where the guide members are arranged to lie transversely between a pair of spaced, parallel, elongated support members and are provided with locating means at each end to cooperate with corresponding means on each of the support members, and with a slot to receive an edge of a board, wherein the support members are each provided with a longitudinally extending rib formation which, in cross section, is of rounded form carried by and symmetrically of the axis of a neck portion, and the end of each guide member defines a correspondingly rounded groove formation provided, in cross section, by a pair of flexible arms whose free ends extend towards one another and thus towards the neck portion of the support member so as to create a snap-on connection onto the rounded rib formation of the support member, and wherein complementary locating formations are provided at spaced positions along the rib formation and in each groove formation to prevent relative movement between the rib and groove formations in the longitudinal direction of the rib formation, each locating formation comprising, respectively, a recess defined in the rib formation and opening to one side only of said axis of symmetry of the neck portion and the rib formation and being at least mostly disposed in the part of the rib formation on said one side of said axis of symmetry, and a complementary projection within and extending from the groove formation and disposed at least mostly on said one side of said axis of symmetry, whereby the arms are enabled to flex relative to one another and grip the rib formation even in conditions wherein the locating formations have not already interconnected during assembly operations.