Sealing structure for a machine for centrifugally casting pipes and machine including said structure

In a centrifugal casting machine comprising a rotary mould, a non-rotating casing surrounding the mould, means defining a cooling water circuit for containing water for cooling the mould, the water circuit comprising means defining a water jacket adjacent and surrounding the mould, an annular radial flange integral with the mould, a ring axially spaced from and coaxial with the flange and integral with the casing, the ring and flange being part of the means defining the water circuit;

• the improvement comprising an annular sealing structure axially interposed between the flange and the ring and consisting of an annular recess which is formed in the ring and defined by two coaxial annular walls radially spaced apart and a transversely extending inner end wall, an inflatable elastically yieldable annular tubular chamber located in the recess in adjoining relation to the inner end wall, means for inflating the annular chamber, a rigid annular sealing member having two coaxial cylindrical surfaces and a planar outer end surface terminating the cylindrical surfaces, the sealing member being mounted in the recess so that said cylindrical surfaces are respectively in close axially slidable contact with said two annular walls and the sealing member is in axially adjoining relation to the chamber, and means for precluding rotation of the sealing member relative to the ring, the sealing member having a portion which extends axially beyond the ring and is defined by a part of said cylindrical surfaces and said outer end surface, which outer end surface is in axially abutting sliding relation to the flange.