US2944502A - Apparatus for manufacturing wheel rims for road vehicles - Google Patents

Description

July 12, 1960 p, LEMMERZ 2,944,502

APPARATUS FOR MANUFACTURING WHEEL RIMS FOR ROAD VEHICLES Filed Oct. 5, 1954 INVENTOIZ APPARATUS FOR MANUFACTURING WHEEL RIIVIS FOR ROAD VEHICLES 7 Paul Lemmerz, Konigswinter, Rhineland, Germany, as-

signor to Firma Lemmerz-Werke G.m.b.H., Konigswinter, Rhineland, Germany 7 Filed Oct. 5,1954, ser. No. 460,483 V Claims priority, application Germany Oct. 10, 1953 2 Claims. 01. 113-49 This invention relates to apparatus for manufacturing fiat-base rims or rims having inclined tire-bead supporting shoulders for road wheels on lorries, omnibuses, roadhaulage vehicles, trailers and other roadvehicles.

According to the presentstate of the art, hot-rolled profiled iron strip is generally used as the starting material for the manufacture of rims of the above noted kind. This profiled iron strip is either suppliedinexact lengths corresponding to the circumference of the rim, or in other'rolled lengths. 'From the former, the rimis rolled directly and is then butt-welded. The. latter are usually rolled into spiral form and from this the rims are cut out, according to their lengths, and are then rounded off and butt-welded.

This starting material consisting of hot-rolled profiled iron strip is, however, very expensive, because therolling tools are very costly, their use being only economic for mass production. Owing to the high costs, it is only in rare cases that two rolling tools of the same profile are installed simultaneously. The manufacturer is consequently dependent to a very great extent for his supplies on the rolling mill in question. However, any such dependence involves a certain degree of uncertainty as re gards production, and this is to be avoided if at all possible. In order, therefore, to save the high cost of rolling tools and in order, moreover, not to be dependent to too great an extent on the rolling mill, it would be desirable to develop a process according to which it would be possible to manufacture from sheet-metal, strip iron or standard mill plate fiat-base rims or rims of present day construction having an inclined tire-bead supporting shoulder, e

Such a process has, however, always been handicapped by considerable difiiculties. The main advantage of the rolled profile'was that it was always possible, by suitable shaping of the rolls, to roll on reinforcements at the places subjected to greatest stress, that is to say, at the dangerous points in the cross-section of the rim, namely, at the point of transition from the rim base to the wheel flange and round the spring ring channel. In the deformation of fiat-base rims or inclined shoulder rims of all types, from sheet metal strip, strip iron, rounded and butt-welded rings in the rolling process, there are even produced at these places certain constrictions which result in an undesirable weakening in the cross-section of the material. In these cases, therefore, taking into account the constriction which is always considerable with these large and thick rims it would be necessary from the outset to make the starting material so thick that the necessary strength and safety of the rim at these critical points is assured. However, this method is unsuitable because of the wastage of material, that is to say, for reasons of whether'it be sheet metal, strip iron or mill plate, willactually be enlarged or thickened at the critical crosssectional areas. The production of this type of fiat-base rim or inclined shoulder rim may if desired be carried out so as to form the complete rim' in one press and using one tool. This process and the tool will now be described in greater detail, with reference to the accompanying diagrammatic drawing. 7 e I V The strip consisting of sheet metal, strip i'ron or uni: versal' mill plate is rolled' in known manner to form a ring and is butt-welded before being shaped. This ring is shown in side elevation in Figure l and in section in Figure 2 of the drawing. 4 e The further processing is carried out using the pressing tool which is shown in section in Figure 3 of the drawing. The ring 10 is first of all placed in a closed die 11 which is adapted to' be swung open after the pressing operation for removal of the formed rim. The bottom edge of the ring 10 is supported at 12 in the first rounded part of the die 11. Disposed at thebottom of the die 11' is a deflecting ring 13, by which the material of the ring is forced laterally outwardly as far as an abutment edge 14 in the 'die, so as to form the groove for the spring ring.

A suitably shaped punch 15 is provided comprising two parts, namely an upper part 16 and a'lower part 17.

The latter is resiliently connected to the upper part 16.

that is to say, towards the inside of the punch.

in the first working step, therefore, the rim is shaped except for the forming of the wheel fiange. The formation of the latter is conveniently carried out in a second working step, the initially-shaped rim being left in the die. This is effected either by means of a second suitablyshaped punch, which is removably fitted in thesame press or by using the same punch as in the first working step but with the interposition of an upper deflecting and shaping ring 20. Under certain circumstances, however, the upper part of the punch could be so formed that the complete rim is produced in one working step.

The annular shaping gap or space extending between the die parts 11 and 13 and punch parts 16 and 17 is widened relative to the wall thickness of the ring 10, at the points of transition from the rim base to the wheel flange 21 and at the rounded portion of the groove or channel 22 for the spring ring, so that a thickening and consequent strengthening of the material is produced at these critical points in the rim section.

It is therefore possible in this manner to achieve the object of the invention, which is to shape various types of fiat base rims and inclined shoulder rims. by a pressing method and at the same time to provide additional strength which is required at critical points ,in the rim a e gees inwardly drawn portion forming said circumferentially extending groove and parts of said radially outwardly extending portion terminating in said axially extending circumferential well being in the operation of the corresponding wheel rim subjected to greater stressesthan the remaining portions thereof and such portions consequent 1y constituting critical stress areas, said apparatus comprising a die and a punch member spaced therefrom so as to form an annular space comprising an inner and an outer wall for receiving a preshaped generally cylindrical sheet metal blank therebetween, the contour of the walls of said space corresponding to the ,final shape of the bed to be formed by the rim to be produced, an annular deflecting member at the bottom of said die and forming a radially outwardly extending annular channel therewith, said punch member comprising a movable lower part and a movable upper part, spring means for interconnecting said lower part with said upper part, an outwardly diverging shoulder formed in said upper part of said punch for engaging said blank edgewise at one end thereof to drive said blank in a first forming operation downwardly into said die, said lower part of said punch being positioned to be movable in the first forming operation into engagement with said deflecting memberto form therewith and with a corresponding portion of an inner wall of said die an annular space terminating in said radially outwardly extending annular channel, a portion of said annular channel corresponding to the critical stress area of the portion of the rim to be formed which has said circumferentially extending groove being wider than the thickness of the material of said blank, whereby the bottom end of said blank being driven in to said die in said first forming operation is deformed to produce said annular groove with the critical stress area thereof thickened as compared with the normal thickness of said blank, the top end of said blank being widened by saidoutwardly diverging shoulder incident to driving said blank in said first forming operation into said die to shape the bottom end thereof so as to form said annular groove, whereupon said punch is withdrawn from said die with said partially shaped blank remaining therein, an annular insert member then being mounted in the outwardly diverging shoulder portion of the movable upper part of said punch member for disposal within said widened end of said blank, said insert forming with the corresponding portion of the inner wall of said die a space having a portion with a width exceeding the thickness of the material of said blank and of a shape to form said other end of the Tim, said outwardly diverging shoulder on said upper part of said punch thereupon in a second forming operation engaging said insert to cause deformation of the blank at the corresponding end thereof so as to form said radially outwardly extending part terminating in said r 4 axially extending end wall with the critical stress area of said part thickened as compared with the normal thickness of the material of said blank.

2. Apparatus for making metallic wheel rims for vehicles having a rim bed defined by an integral tubular wall comprising an intermediate substantially cylindrical portion terminating at one end in a radially inwardly drawn portion forming a circumferentially extending groove and terminating at the other end in a radially outwardly extending portion which in turn terminates in an axially extending circumferential end wall, comprising a die member having an annular inner wall conforming to the shape of the outer surface of the metallic wheel rim, a

punch member movable into and out of the opening in said die member made up of two separable upper and lower parts connected together by spring means, the outer wall of said punch member conforming to the shape of the inner surface of the intermediate portion on the metallic wheel rim, an outwardly diverging shoulder on the upper part of the punch for engaging a wheel rim blank placed in the die member for pressing and shaping the wheel rim blank as it is forced into the space between the wall of the die and the wall of the punch member and forming an outwardly diverging surface on the upper end of the wheel rim blank, and an annular insert member adapted to be mounted in the said outwardly diverging shoulder after said upper part of the punch has been withdrawn and the outwardly diverging surface on the upper end of the wheel rim blank has been formed for cooperating with the upper portion of the die member to form the axially extending circumferential end wall of said metallic wheel rim. 7

References Cited in the file of this patent UNITED STATES PATENTS 865,257 Kohl Sept. 3, 1907 872,168 Clark Nov. 26, 1907 1,336,965 Klaus Apr. 13, 1920 1,388,889 Pomeon Aug. 30, 1921 1,475,032 Shrum Nov. 20, 1923 1,858,047 Ireland May 10, 1932 1,872,067 Furrer Aug. 16, 1932 2,089,784 Cornell Aug. 10, 1937 2,105,289 Lobdell Ian. 11, 1938 2,120,595 Ash June 14, 1938 2,139,833 Le Jeune Dec. 13, 1938 2,154,016 Sinclair Apr. 11, 1939 2,159,901 Le Jeune May 23, 1939 2,349,738 Le Jeune May 23, 1944 2,359,479 Ingersoll Oct. 3, 1944 FOREIGN PATENTS 916,471 France Aug. 19,1946

Images