Patent ID: 6910361

Claim:
A coupling device for releasably securing together the ends of a first and a second longitudinal rail, one end of the second rail having a hollow bore formed therein, the coupling device comprising: a first housing securable to the end of the first rail, one end of said first housing having an elongate load transferring member securable to the first rail and the opposite end of said housing having an elongate spigot, said spigot of a size and shape such that said spigot is closely receivable within the hollow bore in the end of the second longitudinal rail; and, an activator that upon activation causes at least a portion of the periphery of said spigot to expand such that when said spigot is received within the hollow bore in the end of the second rail said spigot releasably secures the ends of the first and second rails together, said spigot and said elongate load transferring member receiving and accommodating bending moments resulting from loads applied to the first and second rails and dissipating bending moments across the first and second rails to resist flexure therebetween, said spigot having a generally hollow interior and including a plurality of balls partially protruding through openings about the circumference of said spigot, said openings of a shape corresponding to said balls but having a diameter smaller than said balls to prevent the complete passage of said balls therethrough, said spigot further including a wedge positioned within said hollow interior of said spigot, said wedge connected to said activator such that said activator causes said wedge to be driven within said hollow interior of said spigot and into contact with said balls causing said balls to partially extend through said openings about the circumference of said spigot, when said spigot received within said hollow bore of said second rail said partially extending balls received within an interior race in said hollow bore and securing said spigot within said hollow bore.