Sheet metal fastener with t-shaped key

Claim 1

A BRACKET FOR JOINING A PAIR OF PLATES OR THE LIKE IN ANGULARLY DISPOSED RELATIONSHIP, COMPRISING A GENERALLY RIGID ANGLE MEMBER HAVING AN UPRIGHT LAND AND A BASE LAND EXTENDING IN ANGULARLY INTERSECTING PLANES FROM A JUNCTION THEREOF TOWARD FREE ENDS OF THE LANDS AND ADAPTED TO BE RESPECTIVELY SECURED TO CORRESPONDINGLY DISPOSED PANELS AT A JUNCTION THEREOF, THE UPRIGHT LAND HAVING A T-SHAPED KEY MEMBER STRUCK THERFROM FOR ANCHORING IN A MATING T-SHAPED SLOT IN AN UPRIGHT PANEL OF ANY OF A RANGE OF THICKNESSES, SAID KEY MEMBER INCLUDING A LEG PROJECTING GENERALLY UPWARDLY FROM AN INTEGRAL CONNECTION WITH THE UPRIGHT LAND ADJACENT SAID JUNCTION AND A TRANSVERSELY DISPOSED HEAD ON A FREE END OF THE LEG, SAID LEG BEING BENT FIRST SLIGHTLY INWARDLY FROM THE PLANE OF SAID UPRIGHT LAND AND THEN SHARPLY OUTWARDLY AND DOWNWARDLY THROUGH AN ANGLE SUBSTANTIALLY MORE THAN 90* TO DISPOSE THE HEAD OUTWARDLY BEYOND SAID UPRIGHT LAND WITH A TRANSVERSE EDGE OF THE HEAD DIRECTED INWARDLY TOWARD THE UPRIGHT LAND FOR ENGAGING THE OUTER SIDE OF SAID UPRIGHT PANEL WHEN IT IS CLAMPED BETWEEN THE HEAD AND THE UPRIGHT LAND, THE FIRST INWARD BEND OF SAID LEG PROVIDING A YIELDABLE LEAD FOR INWARDLY BIASING SAID EDGE OF THE HEAD INTO TIGHT, INCISION ENGAGEMENT WITH SAID UPRIGHT PANEL, SAID UPRIGHT LAND ALSO HAVING INTEGRALLY FORMED PORTIONS PROJECTING UPWARDLY ON OPPOSITE SIDES OF AND BEYOND SAID KEY MEMBER FOR ENGAGING THE INNER SIDE OF SAID UPRIGHT PANEL IN OPPOSITION TO INWARD BIASING FORCES IMPOSED ON THE HEAD OF SAID KEY MEMBER.