US2163003A - Method of die-forming parts - Google Patents

Description

June 20, 1939. GA, LY N 2,163,003

ua'raon 0F DIE-FORMING PARTS Filed Jun 4, 1956 f 2 Sheets-Sheet 2 Patented June 20, 1939 UNlTED STATES PATENT OFFICE METHOD OF DIE-FORMING PARTS George Albert Lyon, Detroit, Mich.

Application June 4, 1936, Serial No. 88,434 a Claims- (01. 113-116) This invention relates to improvements in a method of blanking or die-forming parts, the invention being highly desirable for use in connection with the forming of automotive vehicle parts, such as a tire cover part, a wheel disk part, a hub cap part and the like.

In the making of ornamental wheel disk constructions, hub caps and similar wheel-covering devices, a portion in simulation of a hub cap is usually formed inthe shape of a raised crown embodying an undercut annular indentation or roove, the minimum diameter of which is less than the maximum diameter of the crown portion. In most instances, it has been the custom to spin such a groove formation, and this spinning operation is objectionably dimcult and expensive, and in addition requiresa relatively light grade of metal to perform the operation-with suflicient economy to render it practical. Also the spinning operation has to be employed after the parts have been blanked or stamped with suitable die mechanism, thereby requiring an extra and expensive operation. v

The present invention contemplates the method of fo ming an undercut indentation or recess in an ornamental wheel disk, hub cap or similar wheel-covering element, wherein the spinning operation is eliminated.

Another object of the invention is the provision of a method of forming an undercut indentation or recess in an ornamental wheel covering soley by the use of die mechanism.

Still another object of the invention is the provision of a method of forming a wheel covering with an indented or undercut formation out of relatively heavy or sturdy stock, such, for example, as stainless steel.

It is also a feature of this invention to provide a method of making an automobile wheel covering including the steps of first shaping the disk into a predetermined shape consisting of a crown hub part, and then applying a pressure to the crown part so that the skirt portion thereof is v of a method of forming a wheel disk or similar.

forced to collapse inwardly as a result of the predetermined shape given the wall thereof.

Also an aim of this invention is the provision with a raised crown portion, the skirt of which given a predetermined shape. .By suitable die mechanism, the blank is again compressed in a manner to retain the shape of the crown portion and also the shape of the disk outside the crown portion, the movement of the die members towards each other resulting in a deflection of the skirt inwardly as a result of the predetermined shape given the skirt, thus providing an undercut indentation or groove in the finished article.

Other objects and features of this invention will more fully appear from the disclosures hereinafter, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a fragmentary, vertical sectional view, with parts in elevation, of apparatus embodying principles of the present invention, showing the same in an initial stage of operation;

Figure 2 is an enlarged showing of the structure seen in the left-hand portion of Figure 1;

Figure 3 is an enlarged fragmentary showing of the structure of Figure 1 in a. more advanced stage of operation; and

Figure 4 is a fragmentary, vertical sectional view, with parts in elevation, illustrating apparatus for forming a wheel cover element of slightly different form showing the same in an initial stage of operation.

As shown on the drawings: I

For the purposes if illustration, the structures I selected to be die-formed by the method embodied in this invention is shown in the form of an ornamental wheel disk of a character designed to cover. substantially the entire outer side surface of a vehicle wheel inside the rim. The disk illustrated in Figures 1 to 3, inclusive, is of that type with which a separate hub cap is not utilized, the disk having a central formationin simulation of a hub cap. Of course; the disk may be provided with any desirable contour, depending upon the particular form deemed most desirable for a vehicle to enhance the appearance of the vehicle.

In the present instance, the disk, generally indicated by numeral I, has been preformed to the shape seen in Figures 1 and 2, by any suitable,mechanism, preferably die-forming means.

'Thepreformedshape of the disk I includes a skirt 6 in the crown portion of the disk. An outer annular part I, which may be'given substantially any desirable shape for overlying a particular outer part of the wheel, connects the sldrt 6 with the trim 8, which is the part removed from the blank after the disk has been completely formed.

'On the other hand, this part 8 may be shaped so as to hold a rim-engaging member, if so de- An important feature of the presentinvention is the shape'of the preformed part 6. Wlth reference to Figure 2, it will be seen that this part is arcuate in cross-section, and where this part Joins the portion 1, substantially a groove 8 ,is formed, with the outer wall of the part 6 justabove the groove 8 substantially straight for a short distance. Of course, details in such con--- figuration may be varied, but the illustrated showing is a satisfactory formation for the purposes intended, and is herein set forth as a speciflc example. With such a construction, when pressure is applied to the dome-shaped part of the disk, with the annular part 1 held firmly in position, the skirt 6 will curl inwardly in the region of the groove 8 due to the preformed shape of this skirt.

The apparatus for forming the disk I, as illustrated substantially diagrammatically inthe drawings, includes in general a die block, generally indicated by numeral l0, and apunch die or the equivalent, generally indicated by numeral II. By any suitable means, such as a punch press, for example, these respective die parts It and II may be brought together in a well-known manner. It is preferable, however, that the die block Ill be held in fixed position, and the punch or top die ll be moved relatively thereto.

The'lower die part includes an upstanding die ring |2 defining an inner hollow or cavity forthe reception of a reciprocable die pad II. This pad is normally urged outwardly relative to the ring 12 by any suitable pressure means, such as one or more springs 13a positioned in confronting cavities in the pad l2 and die part III. The outward movement of the pad is limited by one or more pins or studs ll fixed in the ring die I2 each' with its free end projecting into a notch or recess Ila in the pad.

As indicated at It, the upper face of the die ring I2 is shaped to intimately flt the underface oi the part I of the disk. The outer face of the pad I3 is shaped to intimately fit the inner face of the dome part of the disk I out to and including the upper part of the skirt I, as clearly seen in Figure 1.

The upper or punch die includes a base portion It and an integral central projecting portion |1 faced to intimately overlie .the crown part of the disk. This facing is such as to preferably intimately contact the outer surface of the disk including the upper portion of the skirt 6, the die part terminating in an intermediate portion of the skirt, as indicated at I. in Figure 2, but extending radially outwardly beyond the pad l3. Spaced from the part l1, the base portion II is provided with an integral annular depending flange I! defining an annular recess 20 between itself and the part l1. In this recess, an annular die holding element 2| is slidably mounted and held in position by the engagement of a plurality of pins 22 in a like number of recesses 23.

The pins 22 are fixedly positioned in the depending flange l9, and the recesses 23 occur at like intervals in the die holding part 2|, whereby the reciprocal movement of this die part 2| is limited in each direction. A plurality of springs 24, suitably seated in recesses in the base portion l6 and reciprocal die part 2|, normally tendto urge this die part outwardly beyond the central aieaoos part 11. The reciprocal die part 2| is provided with an annular projection 25, the face of which is shaped complementally to the face II on the die block In, so that the portion 1 of the disk may be firmly and intimately clamped between the two die parts.

With reference to Figure 2, it will be seen that the holding die part 2| is preferably provided with an outwardly inclined or tapered inner wall 28 adjacent the skirt I of the disk. This wall 28, while outwardly inclined with respect to the axis of the punch die, is preferably curved so as to be slightly convex, as seen best in Figure 2. It will be understood that the wall portion 28 may be slightly varied in shape consistent with the point at which it is deemed best to have the skirt 8 of the disk contact the same, but it is to be noted that this wall need not of necessity be more than slightly out of alignment from the vertical wall portion thereabove.

After the disk has been preformed in the manner above dwcribed and placed between the die members l0 and H, with the portion 1 of the disk held firmly in position between the face I! of the die "land the part 25 of the reciprocal die part 2|, the die members Ill and II are brought together. In this movement, the projecting portion I! and the annular flange I! of the upper die member move relatively to the die part 2|, and the pad I3 of the lower die is moved against the action of the pressure means Ila relatively to the ring die part 12. The original shape of the crown part of the disk is maintained by the part l1 and the pad 13. Due to the previous formation of the skirt I, this skirt must give and will curve inwardly to form an undercut portion 21, as seen in Figure 8.

When the dies are compressed, the metal of r the skirt 0 is urged at an angle against the wall 28, aiding in the collapsing of the skirt. The part 21 provides an inwardly extending annular flange engageable in a snap-on manner by spring-retaining means carried by a vehicle wheel to hold the disk in place upon the wheel. Thus, it will be seen that no extra parts need be added to the disk, but that the disk may be made out of a single piece of material, die-formed with an undercut groove on its exterior side and an inwardly extending flange on its interior. Further, the disk may be formed of relatively heavy metal of the character of stainless steel, if so desired, and no spinning operations are necessary. In this instance, the part 21 is of relatively small radius. with a relatively sharp curve, and is provided by a simple die-forming operation in an extremely economical manner.

With the disk structure above described, the collapse must occur in the skirt i of the disk when the die members are brought together. The extent of the collapse or, in other words, the depth of the part 21, may be regulated very effectively by the distance which the upper die relatively smooth dome-shaped portion. The upper die mechanism is the same as that previously described, with the exception that the base It is provided with an extension |1a shaped to overlie a smooth dome portion of the disk;

i. e.,' the disk is not provided with the ribs 3 and 5 and the skirt portion 4. In this instance, the

disk to be formed includes a central smooth dome 28 joined to a skirt 29 by a relatively smooth curvature 30. The skirt 29 has a portion extending substantially vertically and terminates in a curvature 3| connecting the skirt with an outer flange portion 32 of the same nature as the aforesaid annular part I, which flange portion terminates in a trim 33 or a part that might subsequently be formed to hold a rim-engaging element. The curvature 30 and the curvature 3| both adapt the skirt so that it will collapse inwardly when subjected to 'axial pressure by the die mechanism.

The lower die, in this instance, does not need a pressure pad, and this die includes a block 34 having an outer annular portion shaped complementally to the part 25 of the upper die so as to intimately receive the underface of the skirt or annular part 32 of the disk. Inside this part, the die may have a substantially fiat surface, as indicated at'35, or, if so desired, the die may be hollowed out to decrease its weight. Due to the fact that the disk has a relatively smooth curvature in the domepart thereof, it is not necessary to have the underface of this part engaged by a die part, since collapsing will occur in the skirt 29, and the dome part will retain its shape without means in engagement with the undersurface thereof. In the previously described form, the the disk was provided with indented parts, such as 4, defined by annular ribs in the disk structure, and to maintain that portion of the disk I in its given shape, it is deemed preferable to use the pad l3. However, with the smooth and even dome shape illustrated in Figure 4; the pressure upon the upper face of the disk is transferred to the skirt 29,'and when the die mechanism is opfor the formation of hub caps, wheel disks and.

similar wheel-covering devices, the apparatus shown and the practice of the method taught herein resulting in a very economical manufacture of such devices from either-light 'or' relatively heavy stock, eliminating costly and expensive operations heretofore required. 4

' I'am-aware that many changes maybe made and numerous details of construction may be.

varied through a wide range without mdeparting from the principles of this invention,,an diI, there fore, do not purpose limitingthepatent granted hereon otherwise. than is necessitatedby the prior art e v Icl'ai-m as my inventionz I 1. The method of forming 'an'undercutjindem tation in acrown-like part comprising'a top portion, an outer portion, and an annular side wall connecting said portions and which side wall extends abruptly upwardly from said. outerf'iportion and 1 then'mergeswithfsaid top portion'gwhich includes: subjecting saidgpart' :to' an" endwlse .pressure while holding. said outerfportion and to I r compel the upper'portion of said .side walltoride along a generallyfrustoeconical guidingsurface whose'greatest diameter-is adjacent said outer portion, while supporting the lower end of said side wall on an abutment surface, thereby to compel a portion of the material insaid side wall to progressively move along the abutment surface and form an imdercut indentation therein adjacent the abutment surface.

2. The method of forming an undercut indentation in a circular member having a crownlike top portion, an outer portion,-and an upstanding side wall connecting said portions, which includes: holding said outer portion against movement and subjecting said crown-like top portion to endwise pressure to force said side wall against an abutment surface adjacent said outer portion, and positioning a guiding surface around said side wall for restraining outward collapse of said side wall, saidguiding surface and said wall being provided with a predetermined shape with respect to each other such that their opposed faces adjacent said outer portion flare slightlyaway from each other.

3. The method of forming an undercut inden:

tation in a circular member having a crown-like top portion, an outer portion, and an upstanding side wall connecting said portions, which includes: holding said outer portion against movement and subjecting said crown-like top portion to endwise pressure to force said side wall'against an abutment surface adjacent said outer portion, and positioning a guiding surface around said side wall for restraining outward collapse of saiddiate fold in a sheet metal member, which includes holding a marginal portion of the member while'feeding an intermediate annular portion of the metal member along a sleeve-like guiding surface against an abutment surface, said annular portion of said member being progressively forced out along said abutment surface away from said guiding surface, thereby forming an intermediate annular fold in said member.

5. The method of forming an annular intermediate fold in a sheet metal member, which includes holding a marginal portion of the member while'feeding' an intermediate annular portion of .the metal member along a sleeve-like guiding surface against an abutment surface, the sleevelike guiding surface being flared away from said annular portion adjacent said marginal portion,

saidannular portion of said member bein Pro-.

, gressively forced outalong said abutment surface away from said; guiding surface, 'thereby forming an intermediate annular fold in said member. 6. The method of forming an annular inter-; mediate fold in a sheet metal'membera'which includes holding a marginal portion of the member while feeding an intermediate annular portion'of like guiding surface andthe intermediate annular.

portion of'said member 'being flared away from. each other adjacent said marginal portion, and

the metal member along a sleeve-like guiding, surface against an abutment surface, the sleevesaid abutment surface being inclined with respect to said guiding surface, said annular portion of 7 said member being progressively forced out along said abutment surface away from said guiding surface, thereby forming an intermediate annular j fold in said'member.

eludes holding a marginal portion of the member while moving an intermediate annular portion of the member at an angle toward a guiding surf ace and against an abutment surface inclined to the guiding surface to compel the moving an? 10 in a circular member having a central part, 8.

marginal part, and an intermediate upstanding annular wall connecting said parts, which includes: holding the marginal portion of said member and forcing the wall portion vertically along a guiding surface toward an abutment surface, thereby compelling the wall portion to move progressively along the abutment surface and form a fold in said member.

GEORGE ALBERT LYON.

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