Coupling device for connecting a first workpiece to a second one

A connecting device for the connection of a first workpiece provided with at least one undercut longitudinal groove to a second workpiece which in turn is provided with a longitudinal groove or grooves, and for the connection of profile bars of polygonal cross-section with longitudinal grooves extending in the side walls of the profile bars, wherein the connecting device has at least one extent which exceeds the width of a narrow groove cross-section of the longitudinal groove or grooves of the second workpiece, wherein the connecting device (40, 60, 60a) has at least one main body (42, 42a, 42b) which can be partially fitted into the narrow groove cross-section (17) of the longitudinal groove of the second workpiece (16) and which has longitudinal lateral shoulder surfaces (45) extending on both sides of a ridge bar (43, 43b), which in the region of the ridge bar has passing therethrough at least one connection member (48, 48b, 48q) which is adapted to be connected to the first workpiece or one of the profile bars (10,10a), wherein the connecting device outside the main body is provided with a connection element (48, 48b, 48q;

• 70) for the second workpiece (10a, 10) wherein the main body (42), at least one of the ends of its ridge bar (43), has a shoulder surface (44) which transversely connects the longitudinal lateral shoulder surfaces (45) as a support surface for a clamping block (50) which can be fixed thereon and has a width which corresponds to the width (e1) of the ridge bar.