Abstract: A stand, table or other supporting structure having one or more supporting leg assemblies connected thereto in such a manner that the leg assemblies can be collapsed into a compact condition to facilitate storage, transportation and handling of the stand, table or other supporting structure. The leg assemblies are retained in their operative position substantially perpendicular to and rigid with respect to the stand to provide a stable support for the stand and for any item or items placed thereon. The leg assemblies are retained releasably in their operative position by a manually operated spring lock device that is provided with a camming feature which enables automatic locking of the leg assembly when oriented into operative position and maintaining a continuous upward bias on the leg assembly for maintaining the rigid perpendicularity of the leg assembly in relation to the stand.