Blind rivet

Claim 1

A BLIND RIVET FOR INSERTION IN A HOLE THROUGH A PANEL, SAID RIVET COMPRISING AN ELONGATED FLAT MALLEABLE STRIP HAVING TAPERED FREE ENDS AND BEING FORMED WITH A MEDIAL LONGITUDINAL SLOT THEREIN, SAID STRIP BEING FOLDED BACK UPON ITSELF AROUND AN IMAGINARY TRANSVERSE CENTERLINE EXTENDING THROUGH SAID SLOT FOR FORMING A SUBSTANTIALLY U-SHAPED SLEEVE WHEREIN THE BASE OF THE U-SHAPED SLEEVE FORMS A SELF-SUPPORTING SUBSTANTIALLY RIGID INNER END FOR INSERTION THROUGH THE HOLE IN THE PANEL, SAID SLEEVE PROVIDING AN ELONGATE CAVITY OR RECTANGULAR CROSS-SECTION IN WHICH THE ARMS OF SAID U-SHAPED SLEEVE FORM SPACED SUBSTANTIALLY FLAT PARALLEL WALLS OF SAID CAVITY, SAID SLOT DEFINING SPACED ELEMENTS AT THE INNER END OF THE SLEEVE ADAPTED TO BE FORCIBLY SPREAD INTO ENGAGEMENT WITH THE UNDERSIDE OF THE PANEL, THE FREE ENDS OF THE STRIP BEING FOLDED TO PROJECT OUTWARDLY OF THE SLEEVE IN OPPOSITE DIRECTIONS FOR FORMING AN INSERTION LIMITING SHOULDER FOR THE RIVET AND THEN BEING BENT INWARDLY UPWARDLY INTO ENGAGEMENT FOR FORMING THE RIVET HEAD AND THEN BEING FOLDED TO EXTEND IN JUXTAPOSED RELATION DOWNWARDLY INTO THE CAVITY WITH THE TAPERED FREE ENDS DIRECTED TOWARD SAID SLOT FOR FORMING TAPERED FREE ENDS DIRECTED TOWARD SAID SLOT FOR FORMING AND HAVING FLAT SURFACES ENGAGEABLE THROUGHOUT SUBSTANTIALLY THEIR ENTIRE LENGTH WITH SAID FLAT WALLS OF SAID CAVITY, WHEREBY, ON INSERTING THE SLEEVE THROUGH THE HOLE AND APPLYING PRESSURE TO THE RIVET HEAD FOR MOVING THE SPREADING MEMBER LONGITUDINALLY INWARDLY IN THE CAVITY TOWARD THE LEADING END OF THE SLEEVE, THE TAPERED FREE ENDS OF THE SPREADING MEMBER ENTER THE SLOT BETWEEN SAID ELEMENTS AND FORCIBLY SPREAD THE LATTER INTO ENGAGEMENT WITH THE UNDERSIDE OF THE PANEL WHILE SAID WALLS OF SAID CAVITY SUPPORT SAID SPREADING MEMBER AGAINST BUCKLING IN A DIRECTION TRANSVERSE TO THE PLANE THEREOF.