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US 12,722,338 B2Granted
Constant strain PEX expansion tool head
AssigneeZurn Water, LLC
InventorGlen Trickle
Life of this patent
Estimating the term…
Abstract
Various improved designs for expansion tool heads are disclosed herein that are structured (1) to provide improved and more-evenly distributed strain in the pipe during the expansion strokes of the tool head which can include more gradually inducing the strain in the pipe and/or (2) to avoid the induction of plastic deformation of the pipe in regions of seal formation between the radial-inwardly facing surface of the pipe and the radially-outward facing surface of the fittings (i.e., the ribs of the fitting) especially in instances in which the tool head is not rotated between separate expansion steps. This may be achieved, for example, by the use of convexly curved outer profiles that limit initial insertion depth of the tool in the pipe prior to expansions and/or by the use of a “hybrid” toothed profile.
Claims23
A method of installing a fitting in a pipe having a first size, the method comprising:
- providing a fitting with a size corresponding to the first size of the pipe, the fitting having an abutment flange and a rib for making a sealed connection, wherein the rib is separated from the abutment flange by a rib distance;
- providing an expansion tool head including a set of jaws sized to correspond with the first size of the pipe, the set of jaws defining a tip end and a base end that is opposite the tip end, the set of jaws being circumferentially positioned about a central axis, and outer surfaces of the jaws having a continuously curved outer profile that protrudes in a convex manner outwardly from the central axis, the outer profile having a rounded shape extending in a direction along the central axis;
- inserting the tip end of the expansion tool head into an axial end of the pipe, wherein the size of the set of jaws is configured to limit an initial insertion distance of the tip end into the axial end of the pipe to an amount less than the rib distance;
- actuating the set of jaws with an actuator while the tip end is located at the initial insertion distance to move the set of jaws outward relative to the central axis from a retracted position to an expanded position thereby expanding the axial end of the pipe, wherein moving the jaws outward from the retracted position to the expanded position includes moving the base end of each jaw of the set of jaws by a first radial distance relative to a central axis, and moving the tip end of each jaw of the set of jaws by a second radial distance relative to the central axis, the second radial distance that the tip end moves being less than the first radial distance that the base end moves, and wherein, in both the retracted position and expanded position, the outer surfaces of the jaws maintain a true round cross-section relative to the central axis;
- and
- installing the fitting at the axial end of the pipe.
3 more elements
A method for expanding an axial end of a PEX pipe to accommodate reception of a fitting, the method comprising:
- inserting a tip end of an expansion tool head into the axial end of the PEX pipe a first axial distance, the expansion tool head including a set of jaws circumferentially positioned about a central axis, wherein each jaw includes a base end and a distal end opposite the base end, outer surfaces of the jaws having a continuously curved outer profile that protrudes in a convex manner outwardly from the central axis, the outer profile having a non-linear shape extending in a direction along the central axis;
- and
- actuating the set of jaws with an actuator to move the set of jaws outward from a retracted position to an expanded position thereby expanding the axial end of the PEX pipe, wherein moving the jaws outward from the retracted position to the expanded position includes moving the base end of each jaw of the set of jaws by a first radial distance relative to the central axis, and moving the distal end of each jaw of the set of jaws by a second radial distance relative to the central axis, wherein the second radial distance that the distal end moves is less than the first radial distance that the base end moves, and wherein, in both the retracted position and the expanded position, the outer surfaces of the jaws maintain a true round cross-section relative to the central axis.
A method for expanding an axial end of a PEX pipe, the method comprising:
- inserting a tip end of an expansion tool head in a retracted position into an axial end of a PEX pipe, the expansion tool head including a set of jaws circumferentially positioned about a central axis, the set of jaws extending from a base end to a tip end parallel to the central axis, outer surfaces of the jaws having a continuously curved outer profile that protrudes in a convex manner outwardly from the central axis, the outer profile having a rounded shape extending in a direction along the central axis, the continuous, convex, curved profile configured to limit an initial insertion distance of the tip end into an end of the PEX pipe and control local deformation of an inner surface of the end of the PEX pipe;
- actuating the set of jaws with an actuator to move the set of jaws outward from the retracted position to an expanded position, wherein, when moving the jaws from the retracted position to the expanded position includes moving each of the jaws at the base end by a first radial distance relative to the central axis, and moving each of the jaws at the tip end by a second radial distance relative to the central axis thereby expanding the axial end of the PEX pipe, wherein the second radial distance that the tip end moves is less than the first radial distance that the base end moves, and wherein a radially outermost ring of the curved outer surface between the base end and the tip end forms a ring of contact at a point within the inner surface of the PEX pipe;
- and
- returning the expansion tool head to the retracted position at the initial insertion distance,
- wherein, in both the retracted position and the expanded position, the outer surfaces of the jaws maintain a rounded cross-section relative to the central axis.
2 more elements
Dependencies are inferred from the claim text.