Patent Description:
PEX tubing is commonly used in plumbing applications as a substitute for copper pipe. PEX tubing can be coupled to fittings in various ways. Crimp rings or clamp rings can be compressed onto the outside of PEX tubing over a fitting to couple the PEX tubing to the fitting. Alternatively, the PEX tube can be expanded and the fitting inserted into the expanded end of the PEX tube. The PEX tube elastically recovers around the fitting to form a tight connection. Tools used to expand PEX tube for this purpose are referred to as PEX expansion tools.

According to its abstract, <CIT> describes a pipe end that is expanded with the aid of an expander tool. The expander tool comprises a plurality of jaws that are radially movable between a retracted and an expanded position. The jaws have outer jaw surfaces which are intended for engagement with the inner surface of the pipe end and which lie adjacent to one another in the retracted position of the jaws and have an at least generally circular arcuate shape in cross-section. The expander tool further comprises a piston or cone with a tapered end for moving the jaws between the retracted and the outer expanded positions and the piston is moved in a reciprocating manner in the axial direction before expanding the pipe end gradually in the stages. The axial reciprocating movement of the piston is guided to rotate the jaws to a certain extent in a circumferential direction after each expansion stage.

According to its abstract, <CIT> describes an expander that includes a first head member, a rotating portion, a plurality of expanding members, and a tightening structure. The first head member and the rotating portion have conical faces corresponding to each other. The rotating portion has a threaded rod section which is screwed with the first head member. The expanding members are arranged around the two conical faces, and the expanding members tend to approach each other due to the tightening structure. When the rotating portion is rotated to approach the first head member, the expanding members are pushed outward to radially expand a tubular element. In addition, a plurality of restriction slots are formed on the conical face of the first head member, and each expanding member forms a corresponding rib slidably disposed in the restriction slot to improve stability.

According to its abstract, <CIT> describes an apparatus for enlarging or belling an extremity of a plastic pipe so that the extremity of an adjacent length of pipe may be received and retained therein. An expanding mandrel is provided, and this mandrel includes expander jaws, expander wedges, and expander wedge guides which engage a tapered spindle. A continuous steel sheath surrounds the mandrel components and longitudinal movement of the tapered spindle provides progressive enlargement or reduction of the mandrel diameter.

The present invention provides, in one aspect, an expansion tool according to appended independent claim <NUM>. The expansion tool includes a working element configured to expand an end of a tube, the working element including a plurality of jaws movable between a closed position and an expanded position, a first mandrel including a first contact surface, and a second mandrel coupled to the first mandrel, the second mandrel including a second contact surface. The first mandrel and the second mandrel are movable together relative to the jaws in a first direction along an axis from a retracted position toward an extended position and in a second direction along the axis opposite the first direction from the extended position toward the retracted position. The first contact surface and the second contact surface are engageable with the jaws to move the jaws from the closed position toward the expanded position in response to movement of the first mandrel and the second mandrel from the retracted position toward the extended position.

The first contact surface may be spaced from the second contact surface along the axis. The jaws may define an internal cavity when the jaws are in the closed position, and the second mandrel may be positioned entirely within the internal cavity when the first mandrel and the second mandrel are in the retracted position. The second mandrel may include a bore, and a portion of the first mandrel may extend into the bore.

The expansion tool may be configured to perform cycles of axially extending and retracting the first mandrel and the second mandrel, the first mandrel and the second mandrel may be movable from the retracted position to the extended position in a first time period, the first mandrel and the second mandrel may be movable from the extended position to the retracted position in a second time period, and the first time period and the second time period collectively may define a cycle time of the expansion tool. The first time period may be longer than the second time period. The cycle time may be one second or less.

The expansion tool may further comprise: a housing; a motor supported by the housing; a battery pack removably coupled to the housing, and the battery pack may be configured to provide power to the motor; and a drive mechanism that may be configured to convert a rotational input from the motor into translational movement of the first mandrel between the extended position and the retracted position. The motor may be operable in a first direction to move the first mandrel from the retracted position toward the extended position, and the motor may be operable in a second direction opposite the first direction to move the first mandrel from the extended position toward the retracted position.

Described herein, in one example, is an expansion tool including a housing, a motor supported by the housing, a mandrel, and a drive mechanism configured to convert a rotational input from the motor into translational movement of the mandrel between an extended position and a retracted position. The expansion tool is configured to perform cycles of axially extending and retracting the mandrel, and an elapsed time for one cycle of moving the mandrel from the retracted position to the extended position and back to the retracted position defines a cycle time of the expansion tool. The cycle time is one second or less.

The expansion tool may further comprise a battery pack removably coupled to the housing, and the battery pack may be configured to provide power to the motor.

The expansion tool may further comprise a working element coupled to the housing, the working element may include a plurality of jaws, and the mandrel may be engageable with the jaws to move the jaws from a closed position toward an expanded position in response to movement of the mandrel from the retracted position toward the extended position. The jaws may be insertable into an end of a PEX tube when the jaws are in the closed position and to expand the end of the PEX tube when the jaws move toward the expanded position. The jaws may define an internal cavity when the jaws are in the closed position. The mandrel may include a first portion defining a first contact surface engageable with the jaws and a second portion defining a second contact surface engageable with the jaws, and the first contact surface may be spaced from the second contact surface.

Also described herein, in another example, is an expansion tool including a housing, a motor supported by the housing, a mandrel, and a drive mechanism configured to convert a rotational input from the motor into translational movement of the mandrel between an extended position and a retracted position. The expansion tool is configured to perform cycles of axially extending and retracting the mandrel. The mandrel is movable from the retracted position to the extended position in a first time period, and the mandrel is movable from the extended position to the retracted position in a second time period different than the first time period. The first time period and the second time period collectively define a cycle time of the expansion tool.

The first time period may be longer than the second time period. The cycle time may be one second or less.

The expansion tool may further comprise a working element coupled to the housing, the working element may include a plurality of jaws, wherein the mandrel may include a first portion defining a first contact surface engageable with the jaws and a second portion defining a second contact surface engageable with the jaws, wherein the first contact surface may be spaced from the second contact surface, and wherein the first contact surface and the second contact surface may bear against the jaws to expand the jaws when the mandrel moves from the retracted position toward the extended position.

<FIG> illustrates an expansion tool <NUM> usable to expand PEX tubing prior to inserting a fitting. The expansion tool <NUM> includes a housing <NUM> (only a portion of which is illustrated in <FIG>) with a handle <NUM> configured to be gripped by a user during operation of the expansion tool <NUM>. The housing <NUM> supports a motor casing <NUM> and a drive casing <NUM>. An actuator <NUM> (e.g., a trigger) for operating the expansion tool <NUM> is positioned on the handle <NUM>.

Referring to <FIG>, a motor <NUM> is supported within the motor casing <NUM>, and a drive mechanism <NUM> is supported at least partially within the drive casing <NUM>. In the illustrated embodiment, a battery <NUM> provides electrical power to the motor <NUM> (e.g., in response to the actuation of the actuator <NUM>). The battery <NUM> is removably coupled to a battery receptacle <NUM> located at a base of the handle <NUM>.

With reference to <FIG>, the drive mechanism <NUM> converts a rotational input from the motor <NUM> into a translational movement of a mandrel <NUM> along a mandrel axis <NUM>. The mandrel <NUM> includes a conical outer surface <NUM> engageable with a working element <NUM> (<FIG>) that is configured to be attached to the expansion tool <NUM>. More specifically, the mandrel <NUM> is driven in a reciprocating manner, to expand and retract the working element <NUM>. The working element <NUM> is movable from an initial or closed position (illustrated in <FIG>) toward an expanded position (<FIG>) in response to movement of the mandrel <NUM> along the axis <NUM> from a retracted position toward an extended position. The working element <NUM> may be biased toward the initial position by a spring element (e.g., an o-ring), such that the working element <NUM> returns to the initial position when the mandrel <NUM> retracts.

Referring to <FIG>, the working element <NUM> includes a plurality of jaws <NUM>, each having an exterior side with a tapered portion <NUM> and a sizing portion <NUM>. When the working element <NUM> is in the closed or retracted position (<FIG>), adjacent jaws <NUM> abut one another, and the tapered portions <NUM> of the jaws <NUM> collectively define a frustoconical profile. The sizing portions <NUM> of each of the jaws <NUM> collectively define a cylindrical profile with a diameter or maximum cross-sectional dimension D1. The dimension D1 is sized for proper expansion of PEX tubing of a nominal size when the jaws <NUM> are inserted into an end of the PEX tubing.

The illustrated working element <NUM> further includes a second mandrel <NUM> at least partially received within an internal cavity <NUM> defined by the inner sides of the jaws <NUM>. Referring to <FIG>, when the working element <NUM> is in the closed position, the second mandrel <NUM> is positioned entirely within the internal cavity <NUM>. The mandrel <NUM> of the expansion tool <NUM> (i.e. the first mandrel) extends into the working element <NUM> and is coupled to the second mandrel <NUM>. In the illustrated embodiment, an end of the first mandrel <NUM> is received within a bore <NUM> in the second mandrel <NUM> to couple the first mandrel <NUM> to the second mandrel <NUM>.

In some embodiments, the mandrel <NUM>, and/or the working element <NUM> may be configured to rotate about the mandrel axis <NUM> before, during, or after expansion of the working element <NUM>. For example, the expansion tool <NUM> may include a rotation assembly with a rotation collar as described and illustrated in <CIT> to Milwaukee Electric Tool Corporation.

The illustrated expansion tool <NUM> includes cycles of axially extending and retracting the mandrel <NUM>, which may include reversing the operating direction of the motor <NUM> in some embodiments. In other embodiments, the expansion tool <NUM> may perform cycles of axially extending and retracting the mandrel <NUM> in response to continuous operation of the motor <NUM> in a single operating direction. In such embodiments, the expansion tool <NUM> may include a motion converting mechanism (such as a cam and follower mechanism) configured to convert a rotational input from the motor <NUM> into reciprocating movement of the mandrel <NUM>.

The expansion tool <NUM> includes a controller (not shown) configured to control operation of the expansion tool <NUM> (e.g., energize the motor <NUM> to rotate the driving mechanism <NUM> a desired number of cycles, reverse the operating direction of the motor <NUM>, etc.). In operation, the working element <NUM> (<FIG>) is inserted into an end of a segment of PEX tubing to be expanded. The tapered portion <NUM> abuts an interior wall of the PEX tubing. The operator depresses the actuator <NUM>, and the motor <NUM> and the drive mechanism <NUM> perform a cycle of axially extending and retracting the mandrel <NUM>, thereby expanding and contracting the jaws <NUM> of the working element <NUM>.

More specifically, the motor <NUM> drives the drive mechanism <NUM> in a first direction (i.e. a forward direction) to extend the first mandrel <NUM> (<FIG>). As the first mandrel <NUM> is extended, it engages the second mandrel <NUM> to move the second mandrel <NUM> forward (i.e. to the left in <FIG>) along the axis <NUM> within the internal cavity <NUM>. The second mandrel <NUM> includes a tapered outer surface <NUM> that engages a corresponding internal surface <NUM> on each of the jaws <NUM> to urge the jaws <NUM> radially outward. The exterior surface <NUM> of the first mandrel <NUM>, which is spaced from the tapered outer surface <NUM> of the second mandrel <NUM> along the axis <NUM>, is engageable with a corresponding internal surface <NUM> adjacent the rear end of each of the jaws <NUM>. Thus, the working element <NUM> engages the jaws <NUM> at two separate, spaced contact areas. By engaging the jaws <NUM> at two separate contact areas, the jaws <NUM> are expanded more evenly. After expanding the jaws <NUM>, the motor <NUM> drives the drive mechanism <NUM> in a second direction (i.e. a reverse direction) to retract the mandrel <NUM>, allowing the jaws <NUM> to retract (e.g., under the influence of a spring).

The elapsed time for a cycle of axially extending and retracting the mandrel <NUM> defines a cycle time TC of the expansion tool <NUM>. More specifically, the mandrel <NUM> is movable from a retracted position to an extended position in a first time period T1 in response to operation of the motor <NUM> in the first direction. The mandrel <NUM> is movable from the extended position to the retracted position in a second time period T2 in response to operation of the motor <NUM> in the second direction. The first time period T1 and the second time period T2 collectively define the cycle time TC of the expansion tool <NUM>.

In the illustrated embodiment, the cycle time TC is about one second or less. In some embodiments, the second time period T2 is less than the first time period T1. That is, the mandrel <NUM> retracts at a faster rate than it extends to take advantage of the reduced load on the mandrel <NUM> when moving toward the retracted position. In some embodiments, the controller may operate the motor <NUM> at two different speeds. Alternatively, the time periods T1 and T2 can be varied in other ways. Retracting the mandrel <NUM> more quickly contributes to a short cycle time TC, which advantageously minimizes the time required to fully expand the PEX tubing to receive a fitting.

Claim 1:
An expansion tool (<NUM>) comprising:
a working element (<NUM>) configured to expand an end of a tube, the working element including a plurality of jaws (<NUM>) movable between a closed position and an expanded position;
a first mandrel (<NUM>) including a first contact surface (<NUM>); and
a second mandrel (<NUM>) coupled to the first mandrel, the second mandrel including a second contact surface (<NUM>);
characterized in that the first mandrel and the second mandrel are movable together relative to the jaws in a first direction along an axis (<NUM>) from a retracted position toward an extended position and in a second direction along the axis opposite the first direction from the extended position toward the retracted position, and
the first contact surface and the second contact surface are engageable with the jaws to move the jaws from the closed position toward the expanded position in response to movement of the first mandrel and the second mandrel from the retracted position toward the extended position.