| 摘要 |
An apparatus for making concrete pipe having vinyl liners. An expandable core is used to hold a tubular vinyl liner. The core has over-center latches which lock the core in an expanded position to hold the liner against the outside surface of the core. The core is a flexible and expandable shell which can be deformed by a forming module into an exact desired shape prior to placing concrete arount the liner and the core. The liner and core are inserted along with a reinforcing cage into a dry-cast concrete form. Then the form is placed over the module and the module is actuated into engagement with the inside surface of the core. The module has a series of disc assemblies, each of which has a plurality of radially moveable shoes capable of being moved to expanded and retracted positions. The form is filled and immediately taken off the module. The form is immediately stripped, but the core is kept in contact with the liner to hold the liner in engagement with the concrete until the concrete sets sufficiently so that a complete bond between the liner and the concrete is established. Finally, the core is retracted and removed from the finished lined pipe.
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