Abstract Making a plastic expansion joint having not more than two convolutions with a uniform wall thickness by inserting a hollow plastic liner into a molding member and applying heat sufficiently to cause the liner to become pliable and applying fluid pressure to the inside of the heated liner whereby the liner will assume the shape of the internal configuration of the member and simultaneously applying an axial force against both ends of the liner thereby pushing the liner into the member allowing the liner to maintain a uniform wall thickness as it assumes the internal shape of the molding member. An apparatus for making a plastic-lined expansion joint from a corrugated expansion joint having flanges at each end and a heated hollow plastic liner positioned therein with the liner ends extending out of the joint and including support means fixedly holding the ends of the expansion joint relative to each other with first and second end plugs engaging opposite ends of the plastic liner. One of the plugs including an air passageway for applying forming pressure inside of the liner. A flare sleeve encircling each end of the liner for supporting the liner with the sleeve being of a length to provide a length of tubing at each end for forming a liner-sealing flange, and a sealing clamp clamping the ends of the liner to the end plugs preventing loss of fluid pressure from the liner interior.
An apparatus for lining a corrugated expansion joint having only one or two bellows having flanges at each end with a heated hollow plastic liner positioned therein with both ends extending out of the joint flanges comprising, support means for supporting and rigidly holding the ends of the expansion joint relative to each other, first and second end plugs each of which is adapted to engage one of the ends of the plastic liner for longitudinally moving the liner ends toward each other, said plugs extending into the ends of the liner against the internal walls thereof for providing internal support to the liner, a fluid passageway in one of the end plugs to provide fluid pressure into the interior of the liner for causing the liner to assume the internal shape of the joint, means for moving both of the end plugs in an axial direction towards each other for pushing the liner into the joint as fluid pressure is applied therein thereby maintaining the wall thickness of the liner uniform, and support means encircling each end of the liner exteriorly but adjacent each end of the joint and being of an internal diameter equal to the internal diameter of the end of the joint thereby providing external support to the ends of the liner for preventing buckling of the liner as the end plugs are moved.
Claim 2
Independent Claim
228 words
An apparatus for lining a corrugated expansion joint having only one or two bellows having flanges at each end with a heated hollow plastic liner positioned therein with both ends extending out of the joint flanges comprising, support means for supporting and rigidly holding the ends of the expansion joint relative to each other, first and second end plugs each of which is adapted to engage one of the ends of the plastic liner for longitudinally moving the liner ends toward each other, said plugs extending into the ends of the liner against the internal walls thereof for providing internal support to the liner, a fluid passageway in one of the end plugs to provide fluid pressure into the interior of the liner for causing the liner to assume the internal shape of the joint, means for moving both of the end plugs in an axial direction towards each other for pushing the liner into the joint as fluid pressure is applied therein thereby maintaining the wall thickness of the liner uniform, and support means encircling each end of the liner exteriorly but adjacent each end of the joint and being of an internal diameter equal to the internal diameter of the end of the joint thereby providing external support to the ends of the liner for preventing buckling of the liner as the end plugs are moved.
Claim 3
Dependent Claim
34 words
The apparatus of claim 1 including, a sealing clamp adapted to clamp the ends of the liner to an end plug for preventing the loss of fluid pressure from the interior of the liner.
Claim 4
Dependent Claim
63 words
The apparatus of claim 1 wherein the support means encircling each end of the liner is a flare sleeve positioned against each end of the joint, said sleeves being of a length to provide a length of liner at each end for forming a liner-sealing flange, said sleeves including a shoulder for limiting the axial movement of the end plugs towards each other.