Positive lock foil blades

Claim 1

A positive locking foil blade mechanism for papermaking machine comprising in combination: a foil having a substantially flat upper face arranged to diverge away from a traveling wire; an upper holder for the foil with means attaching the foil to the upper holder and movable toward and away from said wire; an intermediate holder attached to the upper holder for co-movement therewith; a lower holder attached to said intermediate holder for co-movement therewith and having downwardly extending sides and under-hanging flanges turning toward each other at the lower ends of the sides; a fixed mount having laterally extending ribs respectively received inside said sides and underhanging flanges of said lower holder such that a bottom of said ribs engages said flanges in an operative position of the foil in contact with said wire; means defining a single continuous channel extending longitudinally through the mount, said channel located intermediate said shoulders and flanges; an inflatable element in said channel having an upwardly extending projection positioned for engagement with the lower holder upon inflation of said inflatable element for holding the flanges in engagement with the ribs and positively fixing the operating position of the foil, said projection withdrawing completely into said channel upon deflation of said inflatable element permitting said lower holder to rest substantially flush on said fixed mount with said bottoms of said ribs and said under-hanging flanges out of engagement; and means for inflating and deflating the inflatable element.