Plastic pipe with bell
OwnerTimothy Toliver, Tony Kime +1inventors
InventorsTimothy Toliver, Tony Kime, Hubert Kossner
Life of this patent
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Abstract
A multi-layer bell is formed from the outer shell of a multi-layer pipe in a secondary process, thereby allowing the extrusion process to be conducted at normal speeds. The bell may include a strain limiting membrane fused or mechanically secured between the outer shell extrusion layer and the inner liner extrusion layer, increased hoop or circumferential stiffness. This invention allows the extrusion process to be in its simplest form, with no adjustments to the corrugator or extruder speeds.
Claims15
A method of forming a bell on the end of a plastic pipe, the method comprising the steps of:
- forming a heated segment of plastic pipe having an inner liner and outer layer attached to the inner liner, a portion of the outer layer having a bell shape adjacent an end of the pipe;
- allowing the heated segment of plastic pipe to cool to a temperature wherein the bell shaped outer layer portion holds its bell shape;
- and
- heating the cooled inner liner and forming the inner liner to the bell shaped outer layer portion such that the inner liner substantially covers an inner surface of the bell shaped outer layer portion, inner liner thereby reinforcing the bell shaped outer layer portion.
A method of forming a bell on the end of a plastic pipe, the method comprising the steps of:
- forming a heated segment of plastic pipe having an inner liner and outer layer;
- forming a portion of the heated outer layer to define a bell shape, wherein the portion of the heated outer layer having the bell shape is spaced apart from the inner liner, the inner liner within the bell shaped portion defining an inner bell liner;
- joining a portion of the heated inner liner to a portion of the heated outer layer at a location outside the portion of the heated outer layer having the bell shape;
- cooling the heated segment of plastic pipe to a temperature wherein the bell shaped portion of the outer layer holds its bell shape;
- subsequently re-heating the inner bell liner;
- and
- urging the re-heated inner bell liner into contact with an inner surface of the bell shaped portion, thereby bonding the inner bell liner with the bell shaped portion.
A method of forming a bell on the end of a plastic pipe, the method comprising the steps of:
- providing a segment of plastic pipe having an inner liner and outer layer attached to the inner liner, a portion of the outer layer having a bell shape adjacent an end of the pipe;
- reinforcing the bell shaped outer layer portion with the inner liner, wherein the inner liner substantially covers the inner surface of the bell by heating the inner liner and forming the inner liner to the bell shaped outer shell portion;
- wherein the segment of plastic pipe further comprises an intermediate layer between and connected to each of the inner liner and outer layer, and wherein the method further comprises the step of removing a portion of the intermediate layer from between the inner liner and the outer layer adjacent the end of the pipe prior to reinforcing the bell shaped outer layer portion.
Dependencies are inferred from the claim text.