Abstract A method is described for joining of mating ends of tubular metal sections in the manufacture of window and door frames and the like. The invention employs internal connectors which are wedged outwardly into tight engagement with the internal walls of the sections by pins that are driven through the wall of each section and into slits which are preformed in the arms of the connectors. The pins punch a pellet of metal from the wall and drive it through the slit and into a cold weld with the opposite wall. Very tight and precise joints are attained by the method which comprises compression of the sections together on the joint line and placement of the pins through the sections. Both sections of an in-line joint can be secured in one operation. With mitered, angle joints, one arm of the connector is placed within the first of the two sections slightly past its intended joint line and is locked therein by driving at least one pin through a wall of the section and the slit in the connector arm. The second section is then placed on the remaining arm of the connector and sufficient pressure is applied axially to the sections to compress them together and to draw the arm of the connector into precise alignment in the joint. One or more pins are then driven through the wall of the second section and the slit of the remaining arm to lock the sections together. Also disclosed are joints of relatively large tubular sections with specially designed connectors and a pin with a shape designed to accommodate for manufacturing tolerances in the internal dimensions of the tubular portion of the sections. The method is superior to welding and to other mechanical join of sections. Welding anneals and weakens the metal and requires refinishing to remove marks and weldment. Other mechanical joints are weak, do not seal to the environment, and can break the anodic coating or finish of the metal.
In a method for forming a miter joint between mating ends of sections having at least one tubular element wherein a right angle connector of a width and thickness slightly less than the internal dimensions of the tubular elements and with opposite arms bearing longitudinal slits extending substantially along said arms with a small web therebetween is positioned within the tubular elements of said sections to bridge the juncture of the joined sections and the slit halves of each arm are wedged outwardly into expansion with three of the internal walls of the tubular elements by pins driven transversely through the walls of the sections and into said slits, the improvement for securing a precise alignment between the joined sections which comprises: positioning one of the arms of the connector in the tubular element of a first section at a position therein past its intended joint line, securing said connector in the tubular element of the first section by driving at least one metal pin through a wall of the first section and the slit halves of said arm to expand said slit halves of said arm into a three-walled contact with the internal walls of said tubular element and thereafter positioning the second section on the remaining arm of said connector, applying a force, axially, to said second section to compress said sections and draw said connector into precise alignment on the juncture plane of said joined sections and thereupon driving at least one metal pin through the wall the the second section to enter the slit of the connector''s remaining arm and expand its halves outwardly into binding engagement with the internal walls of the second section
Claim 2
Dependent Claim
279 words
In a method for forming a miter joint between mating ends of sections having at least one tubular element wherein a right angle connector of a width and thickness slightly less than the internal dimensions of the tubular elements and with opposite arms bearing longitudinal slits extending substantially along said arms with a small web therebetween is positioned within the tubular elements of said sections to bridge the juncture of the joined sections and the slit halves of each arm are wedged outwardly into expansion with three of the internal walls of the tubular elements by pins driven transversely through the walls of the sections and into said slits, the improvement for securing a precise alignment between the joined sections which comprises: positioning one of the arms of the connector in the tubular element of a first section at a position therein past its intended joint line, securing said connector in the tubular element of the first section by driving at least one metal pin through a wall of the first section and the slit halves of said arm to expand said slit halves of said arm into a three-walled contact with the internal walls of said tubular element and thereafter positioning the second section on the remaining arm of said connector, applying a force, axially, to said second section to compress said sections and draw said connector into precise alignment on the juncture plane of said joined sections and thereupon driving at least one metal pin through the wall the the second section to enter the slit of the connector''s remaining arm and expand its halves outwardly into binding engagement with the internal walls of the second section
Claim 3
Dependent Claim
31 words
The methOd of claim 1 wherein said connector is inserted into the tubular element of said first section a distance from 0.005 to about 0.02 inch past its intended joint line.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein said connector is inserted into the tubular element of said first section a distance from 0.01 to about 0.015 inch past its intended joint line.
Claim 5
Dependent Claim
30 words
The method of claim 1 wherein said force applied to said sections is from 200 to about 1000 pounds per square inch of cross sectional area of said metal sections.