Adjustable tension butterfly valve ring seal retaining wire - has ends returned to anchor on screw and rotatable washer

摘要

The butterfly valve of the main patent has the sealing ring (12) for the perimeter of the butterfly (8) held in place by a wire ring (6) permitting tension adjustment. This ring is housed in an annular groove in the butterfly periphery, and itself houses the wire ring in a continuous slot (14) which extends for more than half of the thickness of the seal. A radial aperture (30, 32) through the seal and the butterfly body leads the ends of the wire ring into an anchorage recess. One end (34) of the wire is eyeletted and held down by a screw (35, 38). The other wire end (46) is returned in a 'U' formation, with the vertical bar of the 'U' engaged in a hole (45) in a rotatable washer. The wire ring tension is adjusted by rotating the washer. A pin (50) engages a suitable hole (48) in the washer to lock it in the desired position.