Description of the Prior Art Various methods are known for connecting tubing with small diameter to various types of connecting fittings and extrusions used with domestic gas appliances. In the environment of domestic gas appliances, such as a gas stove, tubing attachments to an outlet or inlet portion of a gas valve or other extrusions need to reliably provide and maintain fluid tight seals. A problem with one known arrangement is that when rotational force is applied to the tube, the tube may be caused to rotate so that the gas tight seal is compromised. Typically extremely soft tube material is used so that handling problems can occur during shipping and installation of the tubing. Also a compression fitting often is used for connection of the tubing to a gas valve, adding to the total cost of the system in both material and labor expense.

For example, U. S. patent 3,711,132 discloses a metal tube end fitting including axially spaced circumferential grooves within the bore of an end fitting to which a metal tube is attached by radial expansion are provided with a special contour. The group of grooves nearest the exterior of the fitting is provided with inclined sidewalls, while the inner adjacent group is provided with perpendicular sidewalls.

In the process of assembly, the perpendicular sidewall grooves are substantially filled by the metal of the tubing while the inclined sidewall grooves are only partially filled.

U. S. patent 3,977,710 discloses a tube fitting assembly including a fitting having a first bore through a portion of the fitting and a second bore larger than the first bore and concentric with and through a portion of the first bore. A tubing having a diameter substantially equal to the first bore engages an inside surface of the fitting defined by the end of the first bore. A sleeve having an outwardly extending projection receives the tubing with the projection located within the second bore. Relative movement between the fitting and the tubing radially expands the tubing wall to engage the first and second bores and deforms the sleeve projection outwardly from the tubing to engage the second bore by action of the radial expansion of the tubing wall.

U. S. patent 4,200,314 discloses a tube fitting assembly including a fitting having a first bore through a portion of the fitting and a second bore larger than the first bore and concentric with and through a portion of the first bore. A tubing having a diameter substantially equal to the first bore engages an inside surface of the fitting defined by the end of the first bore. Relative movement between the fitting and the

tube deforms the tubing wall to engage the first and second bores and to form an annular bead of the tubing wall outside of the fitting assembly. The bead is swaged into engagement with an outside surface of the fitting surrounding the second bore.

U. S. patent 5,492,376 discloses a connecting and fitting method provided for metallic pipes with a small diameter. The method includes providing a piping component having a tube wall extending therefrom and defining an expanded chamber. The method further includes providing a pipe member and forming at least one circumferential discontinuity in the pipe member near one end. The end of the pipe member is then inserted through an annular sealing component and into the expanded chamber defined by the tube wall. A diameter reducing area is then formed on the tube wall at a location substantially registered with the circumferential discontinuity in the pipe member to squeeze and tightly seal the sealing component into connecting engagement with the circumferential discontinuity on the pipe member.

U. S. patent 5,573,285 discloses a tube-fitting assembly including a formed tube, first and second threaded fitting member, and a scaling member. The tube has a first annular bead near an end of the tube and a second annular bead outboard of the first annular bead.

The first threaded fitting member surrounds the tube and has a radially inwardly extending first shoulder inboard of the first and second annular beads. The second threaded fitting member has an annular second shoulder at an acute angle to a longitudinal axis of the tube.

The second fitting member surrounds the end of the tube and is in threaded engagement with the second threaded member such that the second should engages an outboard side of the second bead to establish a first seal

between the tube and the second fitting member against leakage of fluid pressure. The sealing member is a washer or O-ring which surrounds the tube and engages the tube and at least one of the first and second threaded fitting members to establish a second seal against leakage of fluid pressure at temperatures which may relax the second fitting member and break the first seal. In a preferred embodiment the sealing member is made of silicone to maintain the second seal at the relatively high temperatures.

A need exists for an improved method for attachment of tubing to valves and extrusions. It is desirable to provide more flexibility in the selection of tubing materials used to form the tubing joints. It is desirable to provide an improved method for attachment of tubing to valves and extrusions and resulting tubing joints that provide effective and reliable operation.

Summary of the Invention A principal object of the present invention is to provide an improved method for attachment of tubing to valves and extrusions. Other objects are to provide a new and improved method and tubing joints that provide effective and reliable operation ; and to provide such method and tubing joints that overcome many of the disadvantages of prior art arrangements.

In brief, a method and apparatus for attachment of tubing to valves and extrusions and tubing joints are provided. An extrusion body portion is provided with a bore for receiving a tube. A groove is formed around the exterior of the body portion. The tube having an outside diameter less than an inside diameter of the bore, is inserted in the bore. Force is applied to the body portion for deforming an area of the body portion

near the groove together with the tube to achieve a mechanical bond.

In accordance with features of the invention, multiple spaced apart grooves can be formed around the exterior of the body portion to provide multiple seals.

One or more of the grooves can be generally cylindrical and/or generally elliptical.

Brief Description of the Drawings The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the drawings, wherein: FIG. 1 is a perspective view illustrating a tubing joint resulting from the method for attachment of tubing to valve body or extrusion of the preferred embodiment; FIG. 2 is a sectional view taken along line 2-2 of FIG. 1 ; FIGS. 3 and 4 are sectional views illustrating successive steps in the method for attachment of tubing to valves and extrusions and illustrating how the seal between the tubing and valve body of FIGS. 1 and 2 is formed; FIG. 5 is a sectional view similar to FIG. 3 illustrating an alternate valve body extrusion portion of the preferred embodiment; FIGS. 6,7 and 8 are enlarged sectional views of alternately configured grooves of the valve body extrusion portion of the preferred embodiment ;

FIG. 9 is a sectional view similar to FIG. 2 illustrating an alternative elliptical groove of the valve body extrusion portion used in the method for attachment of tubing to valves and extrusions of the preferred embodiment; FIG. 10 is a sectional view illustrating an alternative tubing joint and the resulting seal between the tubing and the alternative elliptical groove of the valve body extrusion portion of FIG. 9 ; FIG. 11 is a sectional view similar to FIG. 2 illustrating another alternative arrangement with multiple cylindrical grooves of the valve body extrusion portion of the preferred embodiment; FIG. 12 is a sectional view similar to FIG. 2 illustrating another alternative arrangement with one cylindrical groove and one elliptical groove of the valve body extrusion portion of the preferred embodiment; FIG. 13 is an exploded perspective view illustrating an alternative arrangement for attachment of tubing to valve body or extrusion including a flanged eyelet of the preferred embodiment; FIGS. 14 and 15 are sectional views illustrating successive steps in the method for attachment of tubing to valves and extrusions and illustrating how the seals between the tubing and valve body of FIG. 13 is formed ; FIG. 16 is an exploded perspective view illustrating another alternative arrangement for attachment of tubing to valve body or extrusion including a flanged eyelet of the preferred embodiment;

FIGS. 17 and 18 are sectional views illustrating successive steps in the method for attachment of tubing to valves and extrusions and illustrating how the seals between the tubing and valve body of FIG. 16 is formed; FIG. 19 is a perspective view illustrating another alternative of the valve body extrusion portion used in the method for attachment of tubing to valve body or extrusion also including a flanged eyelet of the preferred embodiment; FIGS. 20 and 21 are sectional views illustrating successive steps in the method for attachment of tubing to valves and extrusions and illustrating how the seals between the tubing and valve body of FIG. 19 is formed.

Detailed Description of the Preferred Embodiments Having reference to the drawings, FIGS. 1-4 illustrate a tubing joint generally designated by the reference character 100 of the invention. Attachment of a small diameter tube or tubing 102 to a valve body 104 or other extrusion is provided with a valve body portion 106 receiving the tubing 102. The valve body portion 106 has a bore 108 receiving the tubing 102 and having an inner diameter approximately equal to an outer diameter of tubing 102. Referring to FIG. 3, a groove 110 initially is formed by drilling or machining around the exterior of valve body portion 106. Groove 110 is generally cylindrical extending around the exterior of the valve body portion 106. FIGS. 3 and 4 illustrate successive steps of the attachment method of the invention, illustrating how the sealed tubing joint 100 between the tubing 102 and valve body portion 106 is formed. In FIG. 3, a force is applied to the valve body portion 106 via a swage or die member 112 longitudinally along the tube 102 as indicated by arrows labeled F as

shown in FIGS. 3 and 4. An applied impact force causes the initial groove 110 to collapse causing an area 114 of valve body portion 106 near the initial groove 110 to deform together with a tubing portion 116 to achieve a mechanical bond forming the tubing joint 100, shown in FIG. 4. Sealing portions 114 and 116 form a mechanical bond defining the tubing joint 100. FIGS. 1 and 2 also illustrates the completed tubing joint 100.

Alternatively, the tubing joint 100 can be formed by crimping or rolling techniques. The initial groove 110 can be crimped or rolled, to deform together the valve body portion 114 and the tubing portion 116 to form the tubing joint 100.

In accordance with features of the attachment- method of the invention, all of the required machining to form the initial groove 110 is done external to the attachment area 114,116 of tubing joint 100. As a result, flexibility is provided as to the time or stage of the valve making process, this machining operation is performed. Further conventional drilling and milling techniques can be used to form the initial groove 110.

Extrusion body portion 106 advantageously is formed of a conventional material uses for gas valves and similar extrusions, such as an aluminum, grade or type 6262T6. Tubing 102 advantageously is formed of aluminum, such as aluminum, grade or type 6061-T6 or 3003-0. Tubing is a small diameter tube, having a wall thickness of 0.028 inch or 0.035 inch and an outer diameter (O. D.), for example, of 0.250 inch, 0.281 inch, 0.291 inch or 0.375 inch. The bore 108 has an inside diameter (I. D.) of 0.251 inch, 0.282 inch, 0.292 inch or 0.376 inch determined by the O. D. of the tubing 102. The valve body portion 106 has an O. D., for example, of 0.375 inch, 0.402 inch, 0.412 inch or 0.500 inch. The machined groove 110 in the valve body portion

106 has an I. D., for example, of 0.315 inch, 0.342 inch, 0.352 inch, or 0.440 inch.

FIG. 5 illustrates an alternate valve body extrusion portion generally designated by 106A in accordance with the present invention. Valve body portion 106A includes a conical or tapered wall portion 130 for seating engagement with an end 132 of the tubing 102. The conical wall portion 130 engages the tubing end 132 to keep the tubing 102 from collapsing.

FIG. 6 illustrates a preferred radius groove configuration for the groove 110. FIGS. 7 and 8 illustrate alternately configured V-shaped and square grooves 110A and 110B of the valve body extrusion portion 106.

Referring to FIGS. 9 and 10, an alternative generally elliptical or inclined groove 140 is machined in the exterior of the body portion 106. The alternative inclined groove 140 creates an alternative tubing joint 100A. An applied force causes the initial groove 140 to collapse causing a ramped valve body area 142 near the groove 140 to deform together with a tubing area 144 to achieve a mechanical bond forming the tubing joint 100A, shown in FIG. 10.

Referring to FIGS. 11 and 12, first and second alternative arrangements of multiple grooves 150 and 152 and multiple grooves 154 and 156 are shown. As shown in FIG. 11, grooves 150 and 152 are generally cylindrical formed around the exterior of body portion 106. In FIG.

12, a generally elliptical groove 154 is formed at an inclined angle around the exterior of body portion 106.

Groove 156 is generally cylindrical formed around the exterior of body portion 106.

Referring to FIGS. 13,14 and 15, there is shown an alternative arrangement for attachment of tubing 102 to the extrusion body portion 106 including a flanged eyelet 160. The flanged eyelet 160 includes a tubular body 162 received within tubing 102 and a flanged end 164. As best seen in FIG. 14, the O. D. of the tubular body 162 is approximately equal to the I. D. of tubing 102. The flanged end 164 of eyelet 160 is seated against the tubing end 132. The extrusion body portion 106 includes a pair of cylindrical grooves 150 and 152 defining a tubing joint generally designated by 100B, as shown in FIG. 15. The tubing joint 100B is formed as described above, by applying a force to the grooves 150 and 152 with an impact force, crimping or rolling to form deformed areas 174 and 176 of the extrusion body portion 106. Deformed areas 174 and 176 of the extrusion body portion 106 form a pair of mechanical seals at tubing areas 178,179 to define the tubing joint 100B. The flanged eyelet 160 provides rigidity for the tubing joint 100B supporting the tubing 102.

With the flanged eyelet 160, tubing 102 can be formed of a softer aluminum, such as aluminum, grade or type 1235F.

The flanged eyelet 160 advantageously is formed of brass when used with an extrusion body portion 106 having a single groove 110 or with multiple grooves, such as grooves 150 and 152 or grooves 154 and 156.

Alternatively, the flanged eyelet 160 can be formed of steel when used with an extrusion body portion 106 including multiple grooves, such as grooves 150 and 152 or grooves 154 and 156. An advantage of using steel to form the flanged eyelet 160 is that the eyelet can easily be detected during processing to determine that it is properly seated at the tubing end 132.

Referring now to FIGS. 16-18, there is shown an

alternative of the valve body extrusion portion 106 used in the method for attachment of tubing 102 also including the flanged eyelet 160. The valve body extrusion portion 106 includes an alternative tapered end portion generally designated 180 and a cylindrical groove 182. Extrusion end portion 180 has a reduced wall thickness. A tubing joint 100C is formed as described above by applying a force to the tapered end portion 180 and the groove 182 with an impact force, crimping or rolling to form deformed areas 184 and 186 of the extrusion body portion 106. Deformed areas 184 and 186 of the extrusion body portion 106 form a pair of mechanical seals at tubing areas 188,189 to define the tubing joint 100C.

Referring now to FIGS. 19-21, there is shown another alternative of the valve body extrusion portion 106 used in the method for attachment of tubing 102 also including the flanged eyelet 160. The valve body extrusion portion 106 includes another alternative end portion generally designated 190 and a cylindrical groove 192. Extrusion end portion 190 includes a cutout portion 193. A tubing joint 100D is formed as described above by applying a force to the notched end portion 190 and the groove 192 with an impact force, crimping or rolling to form deformed areas 194 and 196 of the extrusion body portion 106. Deformed areas 194 and 196 of the extrusion body portion 106 form a pair of mechanical seals at tubing areas 198,199 to define the tubing joint 100D. The notched or square cutout portion 193 of the extrusion end portion 190 forming deformed area 194 closes against the tubing area 198 to prevent rotation of the tubing 102.

While the present invention has been described with reference to the details of the embodiments of the invention shown in the drawing, these details are not intended to limit the scope of the invention as claimed in the appended claims.