Patent ID: 7883332

Claim:
An apparatus ( 10 ) for producing a seal ( 1 ) including a tubular sealing section ( 3 ) of an extruded elastomeric material, including a distribution block ( 11 ) having a terminal die plate ( 12 ) with an annular extrusion orifice ( 15 ) formed therein, corresponding to the cross section of the said tubular section ( 3 ); a chamber ( 18 ) being defined in the distribution block ( 11 ), in communication with the said orifice ( 15 ) and through which an elastomeric material for forming the said tubular section ( 3 ) is fed during operation; a passage ( 21 ) being formed through the die plate ( 12 ), separate and distinct from the said extrusion orifice ( 15 ) and able to put the said chamber ( 18 ) into communication with the external environment, the said passage ( 21 ) being provided to carry a flow of waste elastomeric material; a movable obturator ( 23 ) being associated with the said passage ( 21 ) for controlling the flow of the waste elastomeric material therethrough during extrusion; wherein said obturator ( 23 ) is movable without any interference or contact with the tubular section ( 3 ) of the seal ( 1 ) being extruded and is predisposed to only vary the output cross-section of said passage ( 21 ) for the elastomeric material, whereby in use variations in the wall thickness (WT) of said tubular section ( 3 ) are solely determined by variations in the pressure of the elastomeric material in the said chamber ( 18 ) achieved through the movement of said obturator ( 23 ).