Joint assemblies between structural members

A joint assembly between first plate means and second plate means, said first plate means having opposite sides and peripherally closed non-circular opening means therethrough, said opening means having a first axis and major and minor dimensions transverse to said first axis, said second plate means having a second axis and laterally opposite side edges extending in the direction of said second axis and spaced apart a distance greater than said minor dimension and less than said major dimension, whereby said second plate means can be introduced into said opening means with said opposite edges facing in the direction of said major dimension, said second plate means further including recesses extending laterally inwardly from said opposite side edges and having inner ends spaced apart a distance closely corresponding to said minor dimension, whereby said second plate means when in said opening means can be displaced about said first axis to a locking position in which said recesses receive said first plate means, and an opposed pair of resilient tab means on said first plate means and outwardly adjacent each of the opposite sides of said opening means in the direction of said minor dimension, the tabs of each said pair of tabs being spaced apart in the direction of said major dimension to receive a corresponding portion of said second plate means therebetween when said second plate means is displaced about said axis to said locking position.