Paperboard tray forming machine

Claim 1

A tray forming machine for forming from a flat production blank a paperboard tray having front and rear end panels hingedly attached to side panels by means of folded gusset corner panels and further having folded over corner flaps hingedly attached to the gusset panels and upwardly turned top flaps hingedly attached to the front and rear end panels, comprising: (a) a frame; (b) a plurality of endless traveling mandrels carried by the frame and having releasing means positioned within the mandrels for releasing a formed tray at a pre-determined time; (c) a sheet feeder, positioned above and in front of the traveling mandrels and attached to the frame, for feeding the flat production blank in one direction over the traveling mandrels; (d) first means, positioned above the mandrel, for folding the front panel downward over the mandrel; (e) second means, positioned above the mandrel for folding the rear panel downward over the mandrel as the mandrel advances; (f) a first pair of gusset influencers, positioned on each side of the traveling mandrel, for influencing the front gusset corner panels of the traveling production blank; (g) a second pair of gusset influencers, positioned on each side of the traveling mandrel and upstream from the first pair of gusset influencers, for influencing the rear gusset corner panels of the traveling blank; (h) third means, positioned above the mandrel, for folding the side panels downward over the mandrel after the first and second pair of gusset influencers have influenced the front and rear gusset corner panels; (i) a hot melt applicator, positioned on each side of the traveling mandrel for applying hot melt adhesive first to a portion of the front corner flaps and then to a portion of the rear corner flaps; (j) a pair of plows, positioned on each side of the traveling mandrel, for turning outwardly the corner flaps and folding them against the side panels; (k) a pair of conveyor belts positioned on each side of the traveling mandrel for holding the upwardly turned corner flaps tightly against the side panels until the previously applied hot melt adhesive has set; (l) first means, positioned below the traveling mandrel for pre-breaking a portion of the front panel by positioning it at a pre-determined angle internally of the tray; (m) second means, positioned below the traveling mandrel, for pre-breaking a portion of the rear panel by positioning it at a pre-determined angle internally of the tray; (n) means, positioned in proximity to the mandrel, for activating the releasing means at a pre-determined time to remove the formed tray from the mandrel; and (o) means, positioned above the released formed tray for further pre-breaking the upwardly turned top flaps to a pre-determined position which permits a lid to be later positioned over the tray after it has been filled.