Title:
Wheel rim production method
Kind Code:
A1


Abstract:
Generally, a wheel rim production method in accordance with the invention includes the steps of obtaining a length of extruded heat treatable metal alloy, preferably aluminum alloy, that has a cross-section of a wheel rim; heat treating the length of heat treatable metal alloy; winding or otherwise shaping the heat-treated length of metal alloy into a ring, leaving free ends in the ring forming a ring gap between the free ends; preparing the free ends of the ring for providing mating surfaces for welding; welding the mating surfaces of the ring, preferably using electron beam welding, to form a completed wheel rim; and finishing the completed wheel rim to achieve desired wheel rim parameters. In accordance additional aspects of the invention, additional steps can be carried out prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim.



Inventors:
Schroepfer, David J. (Trinidad, CO, US)
Application Number:
10/215499
Publication Date:
02/12/2004
Filing Date:
08/07/2002
Assignee:
SCHROEPFER DAVID J.
Primary Class:
International Classes:
B21D53/30; C22F1/04; (IPC1-7): C22F1/04
View Patent Images:



Primary Examiner:
WYSZOMIERSKI, GEORGE P
Attorney, Agent or Firm:
S. Michael Bender (St. Petersburg, FL, US)
Claims:

What is claimed as being new and desired to be protected by LETTERS PATENT of the United States is as follows:



1. A wheel rim production method, comprising the steps of: obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim, heat treating the length of heat treatable metal alloy, forming the heat-treated length of metal alloy into a ring, leaving free ends in the ring forming a ring gap between the free ends, preparing the free ends of the ring for providing mating surfaces for welding, welding the mating surfaces of the ring to form a completed wheel rim, and finishing the completed wheel rim to achieve desired wheel rim parameters.

2. The method of claim 1, further including the steps of: prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim, heating a quantity of metal alloy, and, from the quantity of heated metal alloy, extruding a length of heat treatable metal alloy into an extruded length of heat treatable metal alloy that has a cross-section of a wheel rim.

3. The method of claim 1, further including the steps of: prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim, obtaining a length of extruded heat treatable metal alloy, shaping the length of extruded heat treatable metal alloy into a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim.

4. The method of claim 1, further including the steps of: prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim, extruding heat treatable metal alloy into an extruded coil of heat treatable metal alloy that has a cross-section of a wheel rim, cutting off a portion of the extruded coil, and straightening the cut off portion.

5. The method of claim 1, further including the step of trimming the ring prior to welding.

6. The method of claim 1 wherein the heat treatable metal alloy is an aluminum alloy.

7. The method of claim 1 wherein the length of metal alloy is heat treated in a temperature-controlled oven.

8. The method of claim 1 wherein said heat treating the length of heat treatable metal alloy includes a first temperature-controlled heat treating stage followed by a second temperature-controlled heat treating stage.

9. The method of claim 8 wherein the second temperature-controlled heat treating stage includes artificial aging.

10. The method of claim 1 wherein said shaping includes moving a quantity of heat-treated length metal alloy through a die assembly.

11. The method of claim 1 wherein said shaping includes pinch rolling the heat-treated length of metal alloy.

12. The method of claim 1 wherein said shaping includes pinch rolling between complimentary contoured rollers.

13. The method of claim 1 wherein said shaping is carried out by cold forming.

14. The apparatus of claim 1 wherein forming of the shaped length of metal alloy into a ring allows for extra length necessary for final trimming.

15. The method of claim 1 wherein said trimming of the ring prior to welding is carried out by first placing the ring into a fixture.

16. The apparatus of claim 1 wherein preparing the free ends to provide mating surfaces includes preparing the free ends so that the mating surfaces include openings no deeper than 0.005 inch in each mating surface.

17. The method of claim 1 wherein welding the mating surfaces of the ring to form a completed wheel rim is carried out under vacuum conditions.

18. The apparatus of claim 17 wherein the vacuum conditions are maintained in a vacuum chamber.

19. The method of claim 18 wherein the vacuum chamber is maintained at a vacuum pressure of 10−4 Torr or less.

20. The apparatus of claim 1 wherein welding is carried out by means of electron beam welding.

21. The apparatus of claim 1 wherein welding is carried out by means of tungsten inert gas welding in a vacuum chamber.

22. The method of claim 1 wherein preparing the free ends of the ring for providing mating surfaces for welding includes providing bevelled surfaces on the free ends.

23. The method of claim 1 wherein welding is carried out by means of dip brazing welding.

24. The method of claim 1 wherein the width of the ring gap depends upon the method of welding that is employed.

25. The wheel rim made by the method of claim 1.

Description:

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to methods of producing wheel rims and, more particularly, to methods of producing wheel rims which include an extrusion step.

[0003] 2. Description of the Prior Art

[0004] In the prior art, U.S. Pat. No. 4,674,165 discloses a rim production method in which an aluminum alloy extrusion is bended, and ends of the bent extrusion are butt welded, without a description of the butt welding process.

[0005] The present invention relates to a method of producing wheel rims which provide a number of advantages. One advantage is that the weld to produce the wheel rim has excellent weld strength.

[0006] Another advantage relates to the material composing a wheel rim. For purposes of gasoline economy, it is desirable if wheel rims are made from metals that are lighter than steel. In this respect, aluminum alloy is lighter than steel. Yet, it would be desirable to provide aluminum alloy wheel rims that have mechanical properties that rivals mild steel and that may be even greater than mild steel.

[0007] Another advantage relates to types of welding processes that are employed in forming a wheeled rim. For example, with certain types of welding processes, a weld can be carried out in a controlled inert gas atmosphere. However, such a weld may be contaminated by breakdown products of the gas atmosphere. In this respect, it would be desirable if a welding process for producing wheel rims were provided which provides welds which are substantially cleaner than welds carried out in a controlled inert gas atmosphere.

[0008] Some types of welding processes employ heat-affected-zones that are relatively large and that produce sides of welds that are not parallel-sided. Parallel-sided welds are important to create straight strong welds, such as are desirable in a wheeled rim. In this respect, it would be desirable if a welding process were provided for producing a wheeled rim which provides a welding path that is remarkably parallel-sided and that employs a heat-affected-zone (HAZ) which is much less than that produced by other fusion welding processes.

[0009] Thus, while the foregoing body of prior art indicates it to be well known to provide wheeled rims employing a welding process, the prior art described above does not teach or suggest a wheel rim production method which has the following combination of desirable features: (1) has excellent weld strength; (2) provides mechanical properties of heat treatable aluminum alloy which are brought up to a level that rivals mild steel; (3) can provide mechanical properties of some of the heat treatable aluminum alloys which are brought up to a level that is substantially higher than mild steel; (4) provides a substantially cleaner weld than welding carried out in a controlled inert gas atmosphere; and (5) provides a welding path which is parallel-sided and employs a heat-affected-zone which is less than that produced by other fusion welding processes. The foregoing desired characteristics are provided by the unique wheel rim production method of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.

SUMMARY OF THE INVENTION

[0010] To achieve the foregoing and other advantages, the present invention, briefly described, provides in general, a wheel rim production method in accordance with the invention includes the steps of obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim; heat treating the length of heat treatable metal alloy; winding or otherwise shaping the heat-treated length of metal alloy into a ring, leaving free ends in the ring forming a ring gap between the free ends; preparing the free ends of the ring for providing mating surfaces for welding; welding the mating surfaces of the ring to form a completed wheel rim; and finishing the completed wheel rim to achieve desired wheel rim parameters.

[0011] In accordance with another aspect of the invention, the method of the invention includes the following steps carried out prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim. That is, a quantity of metal alloy is heated, and, from the quantity of heated metal alloy, a length of heat treatable metal alloy is extruded into an extruded length of heat treatable metal alloy that has a cross-section of a wheel rim.

[0012] In accordance with another aspect of the invention, the method of the invention includes the following steps carried out prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim. A length of extruded heat treatable metal alloy is obtained and is then shaped into a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim.

[0013] In accordance with another aspect of the invention, the method of the invention includes the following steps carried out prior to obtaining a length of extruded heat treatable metal alloy that has a cross-section of a wheel rim. Heat treatable metal alloy is extruded into a coil of heat treatable metal alloy that has a cross-section of a wheel rim. A portion of the extruded coil is cut off, and the cut off portion is straightened.

[0014] Preferably, the heat treatable metal alloy is an aluminum alloy.

[0015] In accordance with another aspect of the invention, the length of metal alloy is solution heat treated. The length of metal alloy can be heat treated in a temperature-controlled oven. The heat treating the length of heat treatable metal alloy can include a first temperature-controlled heat treating stage followed by a second temperature-controlled heat treating stage. The second temperature-controlled heat treating stage can include artificial aging.

[0016] In accordance with another aspect of the invention, the shaping includes moving a quantity of heat-treated length metal alloy through a die assembly.

[0017] In accordance with another aspect of the invention, the shaping includes pinch rolling the heat-treated length of metal alloy. The pinch rolling takes place between complimentary contoured rollers.

[0018] Alternatively, the shaping can be carried out by other forms of cold forming. Also, the shaping can include net shaping and net shaping with material allowance for final machining.

[0019] In accordance with another aspect of the invention, an additional step of trimming the ring prior to welding is carried out. Winding of the shaped length of metal alloy into a ring allows for extra length necessary for final trimming. The trimming of the ring prior to welding is carried out by first placing the ring into a fixture, whereby the ring is held immobile.

[0020] Preparing the free ends to provide mating surfaces includes preparing the free ends so that the mating surfaces includes openings no deeper than 0.005 inch in each mating surface.

[0021] Preferably, welding the mating surfaces of the ring to form a completed wheel rim is carried out under vacuum conditions. The vacuum conditions are maintained in a vacuum chamber.

[0022] Preferably, welding is carried out by means of electron beam welding in a vacuum chamber. Alternatively, the welding can be carried out by means of tungsten inert gas welding in a vacuum chamber. If desired, preparing the free ends of the ring for providing mating surfaces for welding can include providing bevelled surfaces on the free ends. Preferably, the welding is carried out without using a foreign material. The welding can include using a metal shim to prevent cracking in the ring. Alternatively, welding can be carried out by means of dip brazing welding. The width of the ring gap depends upon the method of welding that is employed.

[0023] The above brief description sets forth rather broadly the more important features of the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contributions to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will be for the subject matter of the claims appended hereto.

[0024] In this respect, before explaining a number of preferred embodiments of the invention in detail, it is understood that the invention is not limited in its application to the details of the construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood, that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0025] As such, those skilled in the art will appreciate that the conception, upon which disclosure is based, may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

[0026] It is therefore an object of the present invention to provide a new and improved wheel rim production method which has all of the advantages of the prior art and none of the disadvantages.

[0027] It is another object of the present invention to provide a new and improved wheel rim production method which may be easily and efficiently manufactured and marketed.

[0028] It is a further object of the present invention to provide a new and improved wheel rim production method which is of durable and reliable construction.

[0029] An even further object of the present invention is to provide a new and improved wheel rim production method which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such wheel rim production method available to the buying public.

[0030] Still yet a further object of the present invention is to provide a new and improved wheel rim production method which has excellent weld strength.

[0031] Still another object of the present invention is to provide a new and improved wheel rim production method that provides mechanical properties of heat treatable aluminum alloy which are brought up to a level that rivals mild steel.

[0032] Yet another object of the present invention is to provide a new and improved wheel rim production method which can provide mechanical properties of some of the heat treatable aluminum alloys which are brought up to a level that is substantially higher than mild steel.

[0033] Even another object of the present invention is to provide a new and improved wheel rim production method that provides a substantially cleaner weld than welding carried out in a controlled inert gas atmosphere.

[0034] Still a further object of the present invention is to provide a new and improved wheel rim production method which provides a welding path which is parallel-sided and employs a heat-affected-zone which is less than that produced by other fusion welding processes.

[0035] These together with still other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will be better understood and the above objects as well as objects other than those set forth above will become more apparent after a study of the following detailed description thereof. Such description makes reference to the annexed drawing wherein:

[0037] FIG. 1 is a flowchart depicting an embodiment of the wheel rim production method of the invention.

[0038] FIG. 2 is a cross-sectional view of an extrusion apparatus used for carrying out a portion of the embodiment of the invention shown in FIG. 1.

[0039] FIG. 3 is a front view of a length of extruded heat treatable metal alloy shown in FIG. 2.

[0040] FIG. 4 is a side view of a roller machine apparatus used in carrying out another embodiment of the invention.

[0041] FIG. 5 is a rear view of the top contour roller and the bottom contour roller of the apparatus of FIG. 4, taken along line 5-5 thereof.

[0042] FIG. 6 is a side view of a ring formed in carrying out the method of the invention.

[0043] FIGS. 7 through 9 disclose ring gaps of decreasing widths.

[0044] FIG. 10 is a perspective view of a length of extruded heat treatable metal alloy being treated by an electron beam in a vacuum chamber.

[0045] FIG. 11 is a perspective view of a coil of extruded heat treatable metal alloy that has a cross-section of a wheel rim.

[0046] FIG. 12 is a perspective view of a cut off portion from the coil shown in FIG. 11.

[0047] FIG. 13 is a perspective view of a ring formed from the cut off portion shown in FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0048] With reference to the drawings, a new and improved wheel rim production method embodying the principles and concepts of the present invention will be described.

[0049] Most generally, a wheel rim production method includes the steps of: obtaining a length of extruded heat treatable metal alloy 16 that has a cross-section of a wheel rim; heat treating the length of heat treatable metal alloy 16; winding, forming, or otherwise shaping the heat-treated length of metal alloy into a ring 12, leaving free ends in the ring forming a ring gap 14 between the free ends, (see FIGS. 6 and 13); preparing the free ends of the ring for providing mating surfaces 38 for welding; welding the mating surfaces of the ring to form a completed wheel rim (see FIG. 10); and finishing the completed wheel rim to achieve desired wheel rim parameters.

[0050] In accordance with a specific aspect of the invention, as depicted in FIGS. 1 and 2, the method of the invention includes the following steps carried out prior to obtaining a length of extruded heat treatable metal alloy 16 that has a cross-section of a wheel rim. That is, a quantity of metal alloy is heated, and, from the quantity of heated metal alloy 28, a length of heat treatable metal alloy 17 is extruded into an extruded length of heat treatable metal alloy 16 that has a cross-section of a wheel rim. As shown in FIG. 2, the quantity of heated metal alloy 28 can be extruded through a die 30.

[0051] In accordance with another specific aspect of the invention, as depicted in FIGS. 4 and 5, the method of the invention includes the following steps carried out prior to obtaining a length of extruded heat treatable metal alloy 16 that has a cross-section of a wheel rim. A length of extruded heat treatable metal alloy 17 is obtained and is then shaped into a length of extruded heat treatable metal alloy 16 that has a cross-section of a wheel rim.

[0052] In accordance with another aspect of the invention, as depicted in FIGS. 11 and 12, the method of the invention includes the following steps carried out prior to obtaining a length of extruded heat treatable metal alloy 16 that has a cross-section of a wheel rim. Heat treatable metal alloy is extruded into a coil 18 of heat treatable metal alloy that has a cross-section of a wheel rim. A portion of the extruded coil is cut off. (see FIG. 12 for cut off portion 20). The cut off portion 20 is formed into a ring 12.

[0053] Preferably, the heat treatable metal alloy is an aluminum alloy. With the prescribed heat treating, the mechanical properties of the heat treatable aluminum alloy are brought up to a level that rivals mild steel. Actually, mechanical properties of some of the heat treatable aluminum alloys are brought up to a level that are substantially higher than mild steel. The heat treatable aluminum alloy can be aluminum alloy 6061 T6. More generally the heat treatable aluminum alloy can be in the 2000, 6000, or 7000 aluminum alloy series.

[0054] In accordance with another aspect of the invention, the length of metal alloy is solution heat treated. The length of metal alloy can be heat treated in a temperature-controlled oven. The heat treating the length of heat treatable metal alloy can include a first temperature-controlled heat treating stage followed by a second temperature-controlled heat treating stage. The second temperature-controlled heat treating stage can include artificial aging.

[0055] In accordance with another aspect of the invention, the shaping includes moving a quantity of heat-treated length metal alloy through a die assembly 30.

[0056] In accordance with another aspect of the invention, the shaping includes pinch rolling the heat-treated length of metal alloy. The pinch rolling takes place between complimentary contoured rollers. More specifically, contoured rollers includes a top contour roller 22 and a bottom contour roller 24. A deflection roller 26 can also be employed. The top contour roller 22, the bottom contour roller 24, and the deflection roller 26 are assembled together in rolling machine.

[0057] More generally, the rolling can be achieved by many varied processes which also includes double pinch, triangle, single wheel driven, double wheel driven, or three wheel driven, guided shoes, sliding plate, etc.. Generally, any type of continuous, geometry-controlling bending operation can be performed for shaping in accordance with the invention.

[0058] Alternatively, the shaping can be carried out by other methods of cold forming. Also, the shaping can include net shaping and net shaping with material allowance for final machining.

[0059] In accordance with another aspect of the invention, an additional step of trimming the ring prior to welding is carried out. Winding of the shaped length of metal alloy into a ring allows for extra length necessary for final trimming. The trimming of the ring prior to welding is carried out by first placing the ring into a fixture. The trimming can remove any gripping features, tangent straight lengths associated with some rolling operations, and any other unwanted imperfections within the circular rim curve. The trimming places the ring into a correct size for accurate final product after welding.

[0060] Preparing the free ends to provide mating surfaces includes preparing the free ends so that the mating surfaces includes openings no deeper than 0.005 inch in each mating surface. In this respect, the mating surfaces are prepared to remove scratches, nicks, straightness, parallelism, and other associated fit parameters. The mating surfaces should also be free of foreign materials caused by grinding or overheating, etc..

[0061] Preferably, welding the mating surfaces of the ring to form a completed wheel rim is carried out under vacuum conditions. The vacuum conditions are maintained in a vacuum chamber 32. The vacuum chamber is maintained at a vacuum pressure of 10−4 Torr or less.

[0062] Preferably, welding is carried out by means of electron beam welding. Alternatively, the welding can be carried out by means of tungsten inert gas welding in a vacuum chamber. If desired, preparing the free ends of the ring for providing mating surfaces for welding can include providing bevelled surfaces on the free ends. Preferably, the welding is carried out without using a foreign material. Preferably, the welding is carried out with the ring in a fixture, whereby the ring is held immobile. The welding can include using a metal shim to prevent cracking in the ring. When ring is made from aluminum alloy, the metal shim employed is made from aluminum.

[0063] With respect to the preferred welding process, electron beam welding is a metal joining process, carried out by an electron beam welding apparatus, wherein coalescence is produced by heat created by the impingement of a concentrated beam 34 of high velocity electrons from an electron source 36 upon a workpiece. The beam is directed at the point or along the line of joining, and its power, spot size and time of application at the point or along the line are varied to control weld width and depth. Because of the high intensity to which an electron beam can be concentrated (e. g. 10 KW/mm2) and its high power capability (60 KW), the width of an electron beam weld in a given thickness of material is characteristically much narrower, and the thickness penetrated in a single pass is much greater than that produced by any other welding process. Also, because the intensity of the beam permits it to develop and maintain a borehole in the workpiece, and therein to apply its energy rapidly and uniformly throughout the depth of that penetration, the weld is created as the beam (and its borehole) are transported along the welding path is remarkably parallel-sided, and the extent of its heat-affected-zone (HAZ) is much less than that produced by any other fusion welding process. An important consequence of these characteristics is that the electron beam welds, because they are parallel-sided create no “wing-up” distortion, because they are much narrower create much less shrinkage, and because they have much less heat-affected-zone, they are stronger.

[0064] In addition, electron beam welds are parallel-sided in that no V-groove or J-groove preparation of the edge is necessary in order to effect penetration of the joint. Square-butt type joints are used for electron beam welding.

[0065] The high intensity of the electron beam, and the high speeds of welding that consequently are possible with the subject method of the invention minimize heat loss in the workpiece due to thermal conduction and make possible important capabilities in the welding of high thermal conductivity metals and refractory metals. With respect to refractory metals, with electron beam welding in accordance with the invention. A substantially cleaner weld is obtained than welding carried out in a controlled inert gas atmosphere.

[0066] After the welding takes place, a wheel ring is formed. Then, the wheel ring is finished, such as by machining (e.g. CNC machining), to obtained desired accuracy in parameters of roundness, profile, and size. The finished wheel rims made in accordance with the invention can be used for motorcycle wheels, automotive wheels, truck wheels, and any other alloy wheels cheaply and economically. After finishing of the wheel rims, in accordance with the invention, if the wheel rims are to be used with wire spoked wheels, holes are drilled in the wheel rims to accommodate the spokes.

[0067] The wheel rims produced in accordance with the invention provide wheel rims that rival wheel rims produced by a forging process. The wheel rims produced in accordance with the invention provide wheel rims that are stronger than wheel rims produced by casting, with no heat treatment necessary after rolling and electron beam welding. The shapes of the wheel rim profiles are limited only by the ability of the welding step (e.g. carried out by computerized welding) to obtain uniform thickness and penetration and the bendability of the shaped length of metal alloy.

[0068] After the wheel rims have been finished in accordance with the invention, they can be anodized or chrome plated or painted to suit the end use. The wheel rims can be mated with other hubs, spokes, blades, and be used to serve many other applications.

[0069] Alternatively, welding can be carried out by means of dip brazing welding. The dip brazing process allow the use of thin (sheet metal) type of pieces to be added to an assembly (in this case a wheel rim assembly). Once the pieces are attached in place by means of tabs, rivets, spot welding, etc., the entire assembly is prepared for dip brazing with the addition of flux, filler shims, etc. and placed into a pre-heated solution of water and salt. Then, the workpieces are taken, and the material is comprised of the filler shims is melted into the adjoining spaces. Afterwards, the entire brazed assembly is removed from the bath, it cooled (with controlled cooling) and cleaned with appropriate processing to prevent corrosion. The brazed assembly can be heat treated to restore the properties of the brazed materials to the maximum strengths. If necessary, final machining can take place after heat treatment.

[0070] With dip brazing welding, hollow wheel rims can be employed, resulting in wheel rims that have reduced rotating mass. Although dip brazing processes may be more expensive than other welding processes, the welding produced by dip brazing welding is very effective and may be desirable. With dip brazing, the pieces can be accurately positioned, weight can be controlled by discretionary use of geometry and parts. Once the dip brazing process has been complete, the final welds have very clean line weld (brazed) joints. These joints have close to parent metal strength. In one respect, the dip brazing process can be used in applications where electron beam welding cannot be employed. More specifically, the dip brazing process can enter spaces that cannot be reached by electron beam welding.

[0071] The width of the ring gap 14 depends upon the method of welding that is employed. As shown in FIGS. 7 to 9, ring gap 14a is relatively large, ring gap 14b has a medium size width, and ring gap 14c has a relatively small width. The ring gap 14c is most appropriate for employing an electron beam welding process step. As a corollary to the ring gap 14 is the concept of a heat-affected-zone. The heat-affected-zone is the region of the ring 12 that is melted during the welding process. In this respect, in FIG. 7 the heat-affected-zone is relatively large, e. g. 0.75 inch, suitable for manual tungsten inert gas. In FIG. 8, the heat-affected-zone is of medium width, e.g. 0.190 inch, suitable for electric resistance welding. In FIG. 9, the heat-affected-zone has a small width, e.g. 0.030 inch, suitable for electron beam welding.

[0072] As to the manner of usage and operation of the instant invention, the same is apparent from the above disclosure, and accordingly, no further discussion relative to the manner of usage and operation need be provided.

[0073] It is apparent from the above that the present invention accomplishes all of the objects set forth by providing a new and improved wheel rim production method that is low in cost, relatively simple in design and operation, and which may advantageously be used to provide excellent weld strength. With the invention, a wheel rim production method provides mechanical properties of heat treatable aluminum alloy which are brought up to a level that rivals mild steel. With the invention, a wheel rim production method is provided which can provide mechanical properties of some of the heat treatable aluminum alloys which are brought up to a level that is substantially higher than mild steel. With the invention, a wheel rim production method provides a substantially cleaner weld than welding carried out in a controlled inert gas atmosphere. With the invention, a wheel rim production method provides a welding path which is parallel-sided and employs a heat-affected-zone which is less than that produced by other fusion welding processes.

[0074] Thus, while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that many modifications thereof may be made without departing from the principles and concepts set forth herein, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use.

[0075] Hence, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification.

[0076] Finally, it will be appreciated that the purpose of the annexed Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. Accordingly, the Abstract is neither intended to define the invention or the application, which only is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.