Corrugated tubing compression tool

A compression tool for compressing and flattening one or both ends of a length of corrugated tubing commonly used for making solar installations. A threaded force-transmitting driver is located within a threaded bore of a force-transmission cylinder. A clamp is disposed in surrounding engagement with the corrugated tubing. Tube retaining lips of the clamp are received between an adjacent pair of corrugatings to hold one end of the corrugated tubing in stationary axial alignment with the force-transmitting driver. A rotational force applied to the threaded force-transmitting driver causes the driver to rotate and move through the threaded bore of the force-transmission cylinder. A compression head at the front of the driver is correspondingly moved towards and into contact with the end of the tubing to compress and flatten the end to prevent a nut from sliding off the tubing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a hand-held tool to compress and flatten one or both ends of a section of corrugated (e.g., stainless steel) tubing of the kind that is commonly used in the solar energy industry. By virtue of the foregoing, a threaded fastener (e.g., a nut) carried by the corrugated tubing will be unable to slide off the compressed end of the tubing during transport or installation.

2. Background Art

It is often desirable to flare (i.e., widen) at least one end of metal tubing which is surrounded by a nut that is slidable along the tubing. The nut is a fastener that is intended to be connected to a complementary fastener so that the tubing can be coupled to an adjacent section of tubing or a fitting. Without having a flared or relatively wide end, the nut could inadvertently slide off the tubing during transport or installation.

A commonly used technique to flare the end of metal tubing is to strike the end with a hammer. However, the hammer striking force is sometimes uneven which may actually damage the tubing and make it unsuitable for coupling to another tube or fitting. In this same regard, a non-uniform flared end produced by a hammer strike may require the use of an additional slip ring to prevent a loss of pressure at the intersection of the coupled tubing sections.

Another technique to widen the end of metal tubing is to use silicone compression and isolation rings around the tube end. Such silicone compression and isolation rings are relatively expensive and are subject to cracking following their prolonged use under high temperature, pressure and mechanical stress conditions.

What is more, a section of metal tubing that is cut from tubing stock will typically have a jagged end surrounded by sharp burs. Such burs are known to cut washers and other seals that are used when adjacent tubing sections are coupled to one another. A seal which is cut will produce leaks and require repair. None of the known commonly-employed metal tube flaring techniques is adapted to simultaneously widen the cut end of the tubing and remove burs therefrom.

SUMMARY OF THE INVENTION

In general terms, disclosed herein is a hand-held compression tool for use in compressing and flattening one or both ends of a section of (e.g., stainless steel) corrugated tubing commonly used in solar energy installations. The compressed end of the tubing prevents a nut that is carried by the tubing from sliding off the tubing during transport or installation. The compression tool includes a tube clamp at one end thereof and a force transmission cylinder at the opposite end.

The tube clamp includes upper and lower cradles which are hingedly connected together and rotatable one above the other to surround and capture the corrugated tubing section to be compressed. Tube retaining lips which project from the upper and lower cradles are received between an adjacent pair of corrugations of the tubing to hold the tubing in stationary axial alignment with the force-transmission cylinder.

The force-transmission cylinder has a threaded bore running axially therethrough for receipt of a correspondingly threaded force-transmitting driver. Located at the front of the force-transmitting driver is a compression head. A deburring rim projects outwardly from the compression head. Located at the rear of the force-transmitting driver is a spindle adapted to be coupled to the socket of an impact wrench.

In operation, the upper and lower cradles of the tube clamp of the compression tool are rotated into surrounding engagement with the corrugated tubing section so as to hold the end thereof to be compressed to spaced axial alignment with the threaded force-transmitting driver of the force-transmission cylinder. The spindle of the force-transmitting driver is coupled to the socket of the power wrench. The power wrench is energized to apply a rotational force to the force-transmitting driver to cause the driver to correspondingly move axially through the threaded bore of the force-transmission cylinder. Accordingly, the compression head of the driver is moved towards and into contact with the tubing section, whereby to compress and flatten the end thereof. The deburring rim which moves with the compression head is received inwardly of the tubing section to automatically and simultaneously smooth any burs that are formed at the compressed end.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring concurrently toFIGS. 1-6of the drawings, details are provided for an easy-to-use hand-held compression tool1that has particular application for compressing one or both ends of a section of corrugated stainless steel tubing50so as to prevent a chrome-plated brass nut52, or the like, from sliding off an end of the tubing50during transport or installation. Such corrugated tubing50is commonly used in solar energy installations, such as for coupling a roof-mounted solar collector to a remote storage tank. However, it is to be understood that the compression tool1herein disclosed can be used in combination with any corrugated stainless steel, copper and similar tubing to be used in a variety of (e.g., plumbing, hydraulic, thermal, etc.) applications.

According to the preferred embodiment, a tube clamp3is located at one end of the compression tool1. A force-transmission cylinder5is located at the opposite end of the tool1. The clamp3and cylinder5are preferably manufactured from forged steel, although the material from which the tool1is made should not be considered a limitation of this invention. As will soon be described, the tube clamp3is adapted to surround and capture the section of corrugated tubing50to be compressed. The force-transmission cylinder5of tool1guides a driver towards and against one end of the tubing50that is captured by clamp3so that the one end can be compressed and widened to form a stop to engage and block the nut52from sliding off the tubing50.

The tube clamp3of compression tool1includes an upper cradle7and a lower cradle9. The upper and lower cradles7and9are pivotably connected to one another by a conventional hinge10such that the upper cradle7is rotatable relative to the lower cradle9between an open position (best shown inFIG. 2) and a closed position (best shown inFIG. 5). In the open position, the upper cradle7is rotated off and away from the lower cradle9at which time the corrugated tubing50can be moved into or out of receipt by the tube clamp3. In the closed position, the upper cradle7is rotated towards and over top of the lower cradle9at which time the tubing50is surrounded and captured by the tube clamp3. The lower cradle has a wide extension or tail11to reinforce the hinge10and prevent a dislocation thereof during the compression of the tubing50.

The upper and lower cradles7and9of tube clamp9have respective smooth and generally round interior cavities12and14that are sized and shaped to accommodate the corrugated tubing50therewithin. Thus, with the upper cradle7rotated to the closed position over the lower cradle9, the tube clamp3will lie in surrounding engagement with the corrugated tubing50to prevent a displacement thereof and hold the tubing in axial alignment with a soon-to-be described driver22that is guided by the force-transmission cylinder5towards one end of the tubing50to be compressed.

To this end, a respective tube retaining lip16and18lies within and extends outwardly from each of the interior cavities12and14of the upper and lower cradles7and9. When the upper cradle7is rotated to the closed position over the lower cradle9, the tube retaining lips16and18thereof will lie opposite and face one another. As is best shown inFIG. 5, the outwardly extending lips16and18are positioned between a pair of adjacent corrugations of the tubing50so as to prevent an axial displacement of the tubing relative to the force-transmission cylinder5. The lips16and18are arranged within the cavities12and14of the upper and lower cradles7and9so as to be received between an adjacent pair of the first few corrugations formed at the end of the tubing50to be compressed.

A threaded force-transmitting driver22is mated to a correspondingly threaded bore24that runs axially through the force-transmission cylinder5of the compression tool1. With the force-transmitting driver22received by the bore24of cylinder5and the corrugated tubing50received by the tube clamp3, the driver22and tubing50will be held in axial alignment (best shown inFIG. 3).

Connected to and projecting from the rear of the force-transmitting driver22is a spindle26. The spindle26enables the force-transmitting driver22to be coupled to an impact wrench60or a similar force-generating tool for a purpose that will soon be described. Connected to the front of the driver22is a compression head30. The compression head30may be detached from the driver22and replaced with a head having a different size. As will also soon be described, the compression head30is movable towards the corrugated tubing50so that a compressive force can be applied to the leading end thereof which has been surrounded and captured by the tube clamp3of the compression tool1. That is, rotational and pushing forces generated by the impact wrench60are transmitted to the compression head30by way of the force-transmitting driver22.

Attached to the compression head30by means of a suitable removable fastener (e.g., a screw)32is a deburring face33that is surrounded by a deburring rim34(best shown inFIG. 2). The deburring rim34cooperates with the compression head30to smooth out and eliminate any burs from the leading end of the tubing50at the same time that the leading end is being compressed by the compression head30. The deburring rim34is sized and (cylindrically) shaped so as to be able to move towards and inside the leading end of the corrugated tubing50while the leading end is being compressed.

The operation of the compression tool1for compressing one or both ends of the section of corrugated tubing50is now described while continuing to refer toFIGS. 1-6of the drawings. With the upper cradle7of the tube clamp3rotated to the open position, the tubing50is laid within the interior cavity14of the lower cradle9. The upper cradle7is then rotated at hinge10to the closed position to lay over top the lower cradle9and thereby surround the tubing50. When the upper cradle7is rotated to the closed position, the tubing50is also received within the interior cavity12of cradle7so that the tube retaining lips16and18which extend from respective cavities12and14are received between a pair of adjacent corrugations of the tubing. As earlier explained, the retaining lips16and18hold the corrugated tubing50in place within the tube clamp3and prevent an axial displacement of the tubing relative to the force-transmitting cylinder5of the compression tool1during the steps of compressing and deburring the tubing.

The impact wrench60is coupled to the compression tool1when the spindle26at the rear of the force-transmitting driver22of the force-transmission cylinder5is mated to a socket62of the wrench. By way of example, the impact wrench60is a ¼ inch, 18 volt tool. As is best shown inFIG. 4, the wrench60is held in one hand, and the compression tool1is grasped in the other. When the trigger of the wrench60is depressed and the wrench is pushed towards the tool1, rotational and pushing forcers are transferred from the socket62of wrench60to the spindle26. Accordingly, the threaded force-transmitting driver22is moved in a first direction axially through the threaded bore24of the force-transmission cylinder5towards the corrugated tubing50that is captured and held in place by the tube clamp3(best shown inFIG. 5).

The compression head30at the front of the force-transmitting driver22is correspondingly moved towards and forced against the leading end of the corrugated tubing50, whereby to compress and flatten the leading end to create a relatively wide head54(best shown inFIG. 6). At the same time that the tubing50is compressed, the deburring rim34that is connected to and moved with the compression head30is rotated inside the leading end of the tubing50(also best shown inFIG. 5) so as to simultaneously smooth out any burs created when the section of tubing is cut off tubing stock.

After compressing and deburring the leading end of the corrugated tubing50, the impact wrench60is used to rotate the compression head30and deburring rim34at the front of the force-transmitting driver22away from the tubing50. That is, the spindle26at the rear of the force-transmitting driver22is rotated in an opposite direction. Accordingly, the threaded force-transmitting driver22is moved axially and in a correspondingly opposite direction through the threaded bore24of the force-transmission cylinder5(best shown inFIG. 6). The upper cradle7of the tube clamp3may now be rotated at hinge10off the lower cradle9so that the wide headed corrugated tubing50can be removed from the compression tool1.

The tubing50can then be returned to the tool1with the trailing end thereof captured and held in place by the tube clamp3in spaced axial alignment with the compression head30of the force-transmitting driver22of the force-transmission cylinder5in order to compress, flatten and debur the trailing end in the same manner as described above.

FIG. 7of the drawings shows the section of corrugated tubing50after the flat and relatively wide compressed head54has been formed at one end thereof by the compression tool1. The compressed end of tubing50can be coupled to an adjacent thermal tubing or fitting by means of sliding the nut52down the tubing50and into surrounding mating engagement with a threaded male connector (not shown) of the other tubing or fitting. A high temperature sealing washer may be required between the nut52and the male connector depending upon application. The interconnection of the headed tubing50and the adjacent thermal tubing or fitting has been demonstrated to sustain working temperatures of greater than 300° F. and working pressures of 1200 psi.