Apparatus for forming tubular fibrous insulatory articles

Claim 1

In an appartus for forming a tubular shaped article from a continuous fibrous blanket having a binder therein, said blanket having a thick body portion and at least one feathered longitudinal edge portion generally paralleling its direction of advance, including a mandrel for winding said blanket around to form said tubular article, a pressure roll for forcefully bearing against said blanket while it is being wrapped around said mandrel, and a conveyor for conveying said blanket to said mandrel, the improvement comprising: means for gathering said feathered edge portion, for displacing said edge portion towards said thick body portion without severing the blanket, and for forming regular ends having a more uniform density on said tubular article, said gathering, displacing, and end-forming means comprising at least one forming member pivotally mounted in the path of said blanket at a point in the path before said blanket reachs said mandrel, said forming member having a first surface extending parallel to the direction of advance of the blanket and inclined to a major face of said blanket at a first obtuse angle, a second surface in the form of an ear contiguous with said first surface and inclined with respect to the advance of the blanket at a second obtuse angle, said second surface being inclined with respect to the face of the blanket a greater degree than said first surface, and a third surface lying in a plane perpendicular to the axis of said mandrel and defining a tube end forming face, said first surface extending around said pressure roll from a location in advance of where said blanket contacts said roll to a point where said feathered edge has been gathered and displaced toward said thick body portion, said second surface being contiguous with and located downstream from said first surface, and said third surface being adjacent to said pressure roll at a point downstream from said second surface.