Apparatus for making girders

Claim 1

APPARATUS FOR MAKING ENDLESS LATTICE GIRDERS HAVING SPACED-APART UPPER AND LOWER CHORDS AND ZIG-ZAG LATTICING OF CHANNEL-SHAPED TRANSVERSE CROSS SECTION JOINING THE CHORDS, SAID APPARATUS COMPRISING, IN COMBINATION: (A) MEANS FORMING A PRODUCTION LINE HAVING AT LEAST THREE PARALLEL PATHS FOR THE UPPER AND LOWER CHORDS AND THE LATTICING; (B) DRUM MEANS ARRANGED AT THE START OF THE PRODUCTION LINE FOR SUPPLYING AT LEAST THREE STRIPS WHICH ARE TO CONSTITUTE THE UPPER AND LOWER CHORDS AND THE LATTICING; (C) PULLING MEANS ARRANGED AT THE DELIVERY END OF THE PRODUCTION LINE FOR PULLING SAID STRIPS ALONG THEIR RESPECTIVE PATHS THROUGH THE PRODUCTION LINE IN A STEP-BY-STEP MANNER, THERE BEING PAUSES BETWEEN THE STEPS; (D) MEANS ARRANGED ALONG THE PATHS TRAVERSED BY THE STRIPS WHICH ARE TO CONSTITUTE THE UPPER AND LOWER CHORDS FOR CONTINUOUSLY IMPARTING THERETO THE SHAPE OF THE UPPER AND LOWER CHORDS WHILE THE STRIPS MOVE ALONG THEIR RESPECTIVE PATHS; (E) MEANS ARRANGED ALONG THE PATH TRAVERSED BY THE STRIP WHICH IS TO CONSTITUTE THE LATTICING FOR IMPARTING THERETO, DURING SAID PAUSES, A CHANNEL-SHAPED TRANSVERSE CROSSS SECTION AS WELL AS A ZIG-ZAG CONFIGURATION, AND FOR PLACING THE ZIG-ZAG LATTICE OF CHANNEL-SHAPED TRANSVERSE CROSS SECTION AGAINST THE CHORDS, SAID LASTMENTIONED MEANS COMPRISING (I) A FIRST DEVICE FOR IMPARTING SAID CHANNEL-SHAPED TRANSVERSE CROSS SECTION TO THE LATTICING STRIP THROUGHOUT LENGTHS EQUAL TO THE REACHES OF THE ZIG-ZAG, THE STRIP BEING LEFT FLAT AT THOSE REGIONS WHERE THE SAME IS TO BE SECURED TO THE CHORDS OF THE GIRDER, AND (II) A SECOND DEVICE FOR IMPARTING THE ZIG-ZAG CONFIGURATION TO THE LAST-MENTIONED STRIP, SAID