(under subclass 179) Devices comprising spaced sealing portions on the same central supporting structure.
(1) Note. Sealing portions separated merely by a washer or washers so that the sealing portions act as a unit are not considered to be spaced in the meaning of the definition of this subclass.
(2) Note. The "sealing portion" is the part which does the actual blocking of flow in the surrounding conduit. It is usually of rubber or deformable but may be a hard machined surface.
(3) Note. The sealing portions must be spaced, from any other sealing portion when in set, expanded condition.
SEE OR SEARCH THIS CLASS, SUBCLASS:
119, for relatively movable spaced packer or plug sealing portions with an expanding anchor.
127, for spaced packer or plug sealing portions and an expanding anchor with a controllable passage between a central chamber and a space below a packer. 146, and 147, for spaced packer or plug sealing portions with a controllable passage between a central chamber and a space below a packer.
186, for spaced packer or plug sealing means with a port between a central conduit and a space between the packer seals and a bypass passage around both packer seals.
