US 2256947 A
Description (OCR text may contain errors)
p 1941- G. s. LEWIS 2,256,947
WHEEL RIM AND METAL TREATING METHOD Filed Jan; 2, 1940 Patented Sept. 23, 1941 WHEEL RIM AND METAL TREATING METHOD George S. Lewis, Evanston, 111. Application January 2, 1940, Serial No. 312,129
This invention relates to a wheel rim and to a metal treating method. The method may be used not only in forming the wheel rim but also in forming treated materials used in the manufacture of other products.
In the manufacture of wheel rims, it has been necessary to employ metal strips of relatively soft or low temper in order to enable the edge portions to be rolled to form beads. Should a metal strip of relatively high temper be used, the edge portions when rolled to form the beads split and break. It is desirable, however, to have the rim formed, in so far as is possible, of metal of relatively high temper in order to reduce the amount of metal used and in order to provide the rigidity desired for the rim.
An object of the present invention is to provide a method by which a rim formed of relatively high temper metal may be produced while at 'the same time forming beads thereon without difliculty. A further object is to provide a rim having heads at the edges thereof formed of annealed metal, the remaining portion of the rim being of relatively high temper metal. A further object is to provide a method of treating metal strips of relatively high temper so that edge portions or other areas thereof are annealed or otherwise treated so as to permit roiling or other manipulation thereof. Other specific objects and advantages will appear as the specification proceeds.
The invention is illustrated, in a preferred embodiment, by the accompanying drawing, in which- Figure 1 is a side view in elevation of apparatus suitable for the practice of my invention; 2, a top plan view of the same; Fig. 3, a broken perspective view of a strip of metal treated in accordance with my invention; and Fig. 4, a transverse sectional view of the rim formed in accordance with my invention.
In the illustration given, I designates a standard supporting a trunnion-equipped reel l l upon which is wound a long strip of metal l2. The reel II is shown equipped with handles l3 which may be employed in the winding of the metal thereon or the dispensing of the same from the spool or reel.
JusWhead of the standard I!) is a frame l4 consisting of three standards, each supporting a platform l5. Mounted on each of the platforms [5 are a pair of feed rollers l6 spaced apart to receive the strip metal l2. The feed or drive rollers l6 are each mounted upon a shaft ll journalled within a bearing 3 secured to the frame M. The shaft I1 is driven by any suitable means (not shown).
Spaced between the standards M are transformers l9 and 20 which are of well-known construction and need not be described in detail.
Transformer I9 is provided with -a pair of spaced roller electrodes 2! adapted to receive between them the metal strip l2 The roller electrodes 2| are of. the t p usually employed for seam welding and need not be described in detail. Each roller is equipped with an edge portion which directly engages the edge portions of the metal strip l2.
The transformer 20 .is likewise equipped with roller electrodes 22 which are spaced apart to receive the metal strip l2.
The metal strip I2 is, after the treating operation, wound upon a second spool or reel 23 equipped with handles 24 and the journal 25, the journal 25 being supported upon a bearing 26 providedby the standard 21.
In the operation of the apparatus, a strip of metal I2 is fed from the spool ll between the feed rollers [6 carried by the three platforms l5, the electrodes 2| and 22 being spaced at such distance from each other as to engage opposite edge portions of the strip-l2. It will be understood that the electrodes are adjustable laterally so as to enable them to engage strips of metal of varying widths. The strip of metal, after being fed between the electrodes, is wound upon the reel 23.
In order to anneal the edge portions of the strip without substantially affecting the temper of the remaining portion of the strip, it is important that, the strip [2 be advanced at such a speed as to maintain the temperature of the edge portions of the strip at an annealing temperature and without allowing the temperature of the edge portions of the strip to exceed these temperatures. In other words, if the metal were allowed to remain between the electrodes for the usual length of time, a welding temperature would be reached, but where the strip is moved forward at a predetermined speed, the temperature created in the metal does not exceed a cherry red temperature. It is found that, where the speed of movement of the metal is thus coordinated with the usual roller electrodes employed for making seam welds, that a quick heating of the areas along the edges of the metal to an annealing temperature is effected without causing this temperature to extend to the remaining portions of the metal. As a result, the major portion of the strip retains its initial temper, while the edge portions have their temper considerably reduced.
By wayof example, it is found that where a half hard cold rolled sheet steel .050 thick is treated in the manner described, the temper midway between the edges on some samples was approximately 753 Rockwell while the temper closely adjacent the edge was 36B Rockwell. Similarly, when strips of full hard cold rolled sheet steel .050 thick were treated as above described, the temper midway between the edges was approximately 94B Rockwell, and the temper closely adjacent the edge 57B Rockwell. In another case, the temper midway between the edges was 963 Rockwell while the temper adjacent the edge was 613 Rockwell. In still another case, the temper midway between the edges was 96B Rockwell, while thetemper adjacent the edge was 603 Rockwell.
In Figure 3 is shown a strip of metal 28 having all edge portions 29 thereof annealed in accordance with the method described. The soft edge portions 29 are readily rolled to form the beads 30 of the tire rim 3|, shown in Fig. 4.
By following the method described, it is possible to form rims of relatively thin metal of high temper, while at the same time the beads 30 may be readily produced without danger of splitting.
It will be understood that the method is not limited to the treatment of edge portions only. If it is desired to bend other portions of. the metal. such as, by creasing the same, and where an annealed area is required, the annealed area maybe produced at any point desired upon the metal strip H by adjusting the position of the metal or electrodes. I have found it particularly useful, however, in the' formation of rims because of the ease with which the edge portions maybe treated without ailecting in any substantial degree the temper oi the remaining portion of the metal. It will be noted that the edge portions 29 are separated by the main width of the metal.
While in the foregoing specification, I have set forth certain details of apparatus and certain steps in the method, it will be understood that these are for the purpose of illustration only and that such details and step-sequences may be varied widely by those skilled in the art without departing from the spirit of my invention.
1. The method of annealing areas of a relatively high temper metal strip comprising subjecting said areas to contact with the electrodes of an electric welding device long enough to raise said areas to an annealing temperature, causing said areas to pass beyond the heating zone after having reached the proper temperature for annealing, thereby preventing the remaining areas from becoming annealed, and slowly cooling said areas. I
2. The method of annealing the opposite edge portions of a high temper metal strip comprising subjecting each of said edge portions to contact with a pair of spaced electrodes of an electric welding device long enough to raise each edge portion to an annealing temperature, the heating of said edge portions being carried on simultaneously, causing said edge portion to pass beyond the said device after having reached the proper temperature for annealing, thereby preventing the remaining portions from becoming annealed, and slowly cooling said edge portions.
GEORGE S. LEWIS.