Mining machine with apparatus for supplying dust suppression liquid to rotating cutting head

Claim 1

In a mining machine including a frame; a mining head mounted for rotation on said frame and having cutter bits and liquid spray means mounted thereon; a stationary member attached to the frame and having a cylindrical surface concentric with a cylindrical surface of the rotatable mining head to form an annular interface between the stationary and rotatable members; means in the stationary member for conveying liquid to the interface; and means in the rotatable member for conveying liquid from the interface to the liquid spray means; and further including an improved means for conveying the liquid from the stationary member across the annular space to the rotating member comprising: a pair of spaced parallel annular grooves in the surface of one of the members; fluid activated seals disposed in each groove to form an annular space between said seals, said rotating member and said stationary member, said annular space being in communication with the fluid conveying means at both members, each of the seals comprising a split outer ring of low friction material and having overlapping stepped ends allowing expansion and contraction of the ring and a split inner ring of resilient material adapted to push radially outwardly against the outer ring to hold the outer ring in gentle sliding contact with the surface of the other member; said grooves being sufficiently deep to provide an annular space under the seals such that when liquid flows in the annular space the pressure of the seals against the surface of the other member is increased.