Concealed clip for hollow strips

DETAILED DESCRIPTION We claim: 1.
In combination, two intersecting hollow strips of equal cross-sectional dimensions and a concealed clip for interlocking said strips, comprising two hollow strips of equal cross-sectional dimensions each having an equilateral parallelogram cutaway portion on one face, with two sides thereof extending across the full width of said strips, and two rectangular cutaway portions adjacent to said equilateral parallelogram cutaway portion located one in each side of said strip forming an equilateral parallelogram void in each strip extending through half the thickness of said strip, leaving a remaining half thickness opposite thereto, said hollow strips being interengaged with said void of each strip engaging a said remaining half thickness of the other said strip, and a semi-rigid clip disposed within said hollow strips at the intersection formed by said interengagement of said strips, said clips having a center portion and four outwardly directed legs, two oppositely directed legs extending into two oppositely directed portions of one said hollow strip, and two other oppositely directed legs extending into two oppositely directed portions of the other hollow strip, said four outwardly directed legs being formed to urge said two hollow strips together in said interengaged relation including upwardly extending portions on two oppositely directed legs and downwardly extending portions on the two other oppositely directed legs, said upwardly extending portions having a normally upwardly extending extent and said downwardly extending portions having a normally downwardly extending extent such that when said hollow strips are placed fully together in interengaged relation said upwardly extending portions and said downwardly extending portions are still compressed and tending to urge said hollow strips tightly together.
2.
The combination of claim 1 wherein said semi-rigid concealed clip consists essentially of a flat center portion and four legs extending outwardly therefrom in a form which is flat for part of the extent and having on the outer ends thereof a first portion extending out of the plane of the said center portion and a second portion extending back toward the plane of the said center portion, with the directions out of said plane of the said first portion of adjacent legs being opposite directions, and being directed toward the face of the respective hollow strip having therein said void