US3460500A - Flanging die - Google Patents

Description

T. A. MCCOY 3,460,500 I FLANGING DIE Filed Feb. 14, 1967 INVENTOR Thomas A. McCoy um? cum ATTORNEY United States a Patent Office 3,460,500 Patented Aug. 12, 1969 Int. Cl. B21d 3/14 US. Cl. 113-120 7 Claims ABSTRACT OF THE DISCLOSURE Background of the invention Each such cylindrical body is produced from an initially flat plate of sheet metal; the opposite ends of such plate being-in the body-forming operation-brought together and welded along a longitudinal or side seam. Thereafter, the cylindrical body is sized on an expanding mandrel which causes said body to shorten somewhat except along the side seam which resists such shortening. Consequently, at and immediately adjacent each end of the side scam, the body has a slight projection extending beyond the normal plane of the related end of said body. Following. the sizing operation,. the cylindrical body is forcefully relatively driven axially into an annular flanging die wherein the related end of the body is turned outward as a continuous flange whichwhen formedabuts against a stop shoulder. However, when the cylindrical body has a projection as hereinbefore describedat said related end and in the zone of the side seam, such projection strikes the stop shoulder prematurely; i.e. beforethe full flange is die-formed. This results in excessive pressure bn the side seam and causes buckling of the body along such seam. It is to the solution of this problem that the present invention is directed.

Summary of the invention The present invention provides, as a major object, a novel flanging die which is constructed in a manner to automatically compensate for the projection, in the zone of the side seam, on the related end" of the cylindrical body when the same is relatively driven into said flanging die; the arrangement being such that 'no excessive pressure is imposed on the side seam, and as a result the cylindrical body does not buckle along such seam.

The present invention provides,as another object, a flanging die-as above-wherein said compensating action is attained through the medium of. a stop shoulder comprised of a multiplicity of segments, any one of which can yield radially outward during the flanging operation and upon forceful engagement by the projection on said related end of the cylindrical body.

The present invention provides, as a further object, a flanging die which is designed for ease and economy of manufacture.

The present invention provides, as a still further object, a practical, reliable, and durable flanging die and one which is exceedingly effective for the purpose for t which it is designed.

Brief description of the drawings FIG. 1 is a plan view of the improved flanging die, partly broken away and in section.

FIG. 2 is a diametral section of the die; the view being taken substantially on line 2-2 of FIG. 1, and showing a cylindrical body as flanged by such die.

FIG. 3 is a fragmentary plan of the die, shown with a cylindrical body being flanged.

FIG. 4 is a side view, on reduced scale, of a typical seamed cylindrical body to be flanged; the body being shown after the sizing but prior to the flanging thereof.

Description of the preferred embodiment Referring now more particularly to the drawings and to the characters of reference marked thereon, the cylindrical sheet metal body 1which is to be flanged at one end-is forrneclas usual-from an initially flat plate, the ends of which are brought together and welded to provide a longitudinal or side seam 2 which is relatively thick. Upon subsequent sizing of the body 1 on an expanding mandrel, said body is shortened somewhat except in the zone of the seam 2 which resists such shortening action. As a result, each end of the body is left with a projection 3 in said zone after the sizing operation is completed; such projection 3, while slight, is nevertheless distinct and extends beyond the normal plane of the related end of the body.

The flanging die, which is the subject of this invention, comprises a rigid ring 4 adapted to be mounted in a suitable manner either in a fixed position or for vertical movement as may be required by the type of machine in which the die is mounted.

Formed with the ring 4 and upstanding from the base B of the die is a circular flanging die head 5; the radially outer surface 6 of said die head being formed, from the top down a certain distance, with a convex curvature or slope as indicated at 7. A relatively short vertical face 8, extending downward from the curved face 7, merges with a short and somewhat sharply concavely curved ledge 9 which projects radially out to the periphery 10 of the base B of the die. The diameter of the die head 5 at the vertical face 8 is such as to snugly engage in the body 1 being flanged, as shown in FIG. 2.

Surrounding and as a whole substantially engaging the periphery 10 of the base B of the die is a continuous but segmental band, indicated generally at 11, which extends from adjacent the bottom of the die to a point 'a short distance above the ledge 9 whereby said segmental band 11, ledge 9, and face 8 form a circumferential endless trough 12.

The band 11 comprises a plurality of separate but closely end-toend, radial segments 13, each of which has an inner edge circumferentially of a length not less than the width ofany given projection 3. Adjacent segments 13 are pivotally connected together at the top and bottom by links 14; corresponding top and bottom links 14 being connected at the ends to the related segments 13 by pivot pins 15. As so connected, any individual segment 13 is capable of limited radially outward movement.-

In order to maintain the segmental band 11 against vertical movement relative to the base B of the die, each segment 13 is formed with a flat rigid tongue 16 project ing radially inward and slidable in a circumferential groove 17 in said base of the die.

By reason of the described construction of the die head 5 and the arrangement of the band 11 therewith, said band forms a stop shoulder for the radially outer edge of the continuous flange 18 as formed on the cylindrical body 1. Such flange 18 is, of course, formed by exerting pressure in an axial direction to relatively force the cylindrical body 1 onto the die head 5 until the related, initially straight end of the body is outturned to the desired curved or flange shape by engagement with the curved ledge 9 of the die, and which ledge forms the bottom of the trough 12.

As the radially outer wall of said trough (i.e. the aforesaid stop shoulder) is formed by the segments 13, and as each such segment is individually yieldable outwardly to a limited extent, as previously noted, the following advantage ensures.

When the projection 3 on the related end of the body 1 becomes horizontal and moves radially outwardly on ledge 9 during completion of formation of the flange 18 but before the latter bears against the stop shoulder formed by band 11, the segment 13 engaged by said projection is forced radially outward; the corresponding connecting links 14 swinging out to follow the movement of said segment, as shown in FIG. 3. As a result of such I engaged segment 13 yielding outwardly, the excessive pressure which would otherwise be imposed on the side seam 2 by the projection 3 when the flange 18 is completed and strikes the band 11, is avoided and the body is not buckled along such seam. In other words, the premature engagement of the projection 3 with a segment 13 of band 11 is wholly compensated for by the outward yielding movement of said segment upon the flange 18 being completed and coming to a full-circle stop against the band 11.

By reason of the multiplicity of segments 13 used in the construction of the band 11, it is not necessary to initially dispose the body 1 in any specific or particular position relative to the band 11, since the projection 3 will always engage one or the other of such segments.

Whilefor the purpose of clear illustration-only one segment 13 is shown in FIG. 3 as yielding outwardly, it is to be recognized that there will in actual practice be a like but lesser outward displacement of the adjacent or near segments 13; this because of the interconnection of said segments 13 by the pivoted links 14.

From the foregoing description, it will be readily seen that there has been produced such a flanging die as substantially fulfills the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the flanging die, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

I claim:

1. In a flanging die which includes a circular'die head adapted to fit into a cylindrical, sheet metal body from one end thereof, and means forming a flanging trough about the die head facing and in position to forcefully receive said end of the body in outturned flange-forming relation; said means including a band surrounding the die head and forming the outer wall of the flanging trough, said wall providing a stop. shoulder for the flange as formed, and said band being segmental and yieldable in a radially outwardly direction :at individual points in the circumference thereof.

2. A flanging-die, as in claim 1, in which saiduband comprises a multiplicity of connected elements individually yieldable in said direction. r p 3. A flanging die, as in claim 1; 'including a radially outwardly extending ledge forming the bottom of "the flanging trough, and the band extending closely about the ledge; said band comprising a multiplicity of connected elements individually 'yieldable in said direction and away from the ledge.

4. A flangng die, as in claim 1, in which said band comprises. a multiplicity-0f separate rigid segments disposed .end to end,'and links spanning between and pivotally connecting adjacent segments together; the axes of the link pivot being parallel to the axis of said band.

5. A flanging die, as in claim 4, including means supporting the band segments individually from the die head for radial movement relative thereto but confined against movement axially thereof.

6. A flanging die, as in claim 5, in which the die head includes a base, and said supporting means comprises a tongue extending radially inward from each segment; the 'die -head base having a circumferential groove in which the tongues are slidably engaged.

7. A flanging die, as in claim 1, in which the flanging groove includes a radial bottom ledge about which the band closely engages, and said band comprises a multiplicity of arcnate end-to-end segments pivotally connected for individual yielding in said radially outward direction; each segment being formed with an integral tongue projecting radially inward below said ledge, and the die head including a base' having a circumferential groove into which such projecting tongues slidably engage.

7 References Cited UNITED STATES PATENTS RICHARD J. HER-BST, Primary Examiner US. Cl. X.R.

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