US3038430A - Method of making sheet-metal parts - Google Patents

Description

June 12, 1962 KQLTON 3,038,430

METHOD OF MAKING SHEET-METAL PARTS Filed Dec. 50, 1959 INVENTOR DAVID KOLTON ATTORNEY United rates @atent @fifiee 3,938,436 i atenteri June 12, 1962 spasms NETHGD F MAKENG fiHEET-METAL PARTS David Koiton, Newark, NJ assignor to Federal Pacific Eiectric Company, a corporation of Delaware Filed Dec. 30, 1959, Ser. 1 o. 862,333 2 Claims. (Cl. 113-116) The present invention relates to methods of forming metal parts.

An object of this invention is to avoid waste in making parts of sheet-metal and more particularly parts having a split ring having an integral strip extension. An element of this form is used as the electrical terminal connection for a fuse holder, but it will be apparent that the concepts involved apply to other products.

As will be seen from the description of an illustrative embodiment shown in the drawings and described in detail below, the article is stamped from sheet-metal; and at least part of the strip portion extending from the ring is taken from the sheet-metal stock that would normally be waste, within the ring. In order to do this, the slit in the ring is initially made wide enough to provide material for the strip portion, even though that width is greater than is permissible in the finished article; and portions of the ring are deformed either before or during the blanking operation. Thereafter the deformations are flattened causing the over-size width of the opening in the ring to close to the desired dimension.

The nature of the invention will be better appreciated from the following detailed description of the illustrative embodiment shown in the drawings, wherein:

FIG. 1 is the plan view of the sheet-metal article to be formed;

FIG. 2 is the side elevation of the article in FIG. 1;

FIG. 3 is the plan view of a continuous series of metal blanks as they are related to each other in the blanking process, the broken lines in FIG. 3 representing marginal edges of a strip of sheet-metal from which the blanked parts illustrated are taken; and

FIG. 4 is an end view of a part in FIG. 3, viewed from the right.

Referring now to the drawings, the article in FIGS. 1 and 2 is seen to include a split-ring It} with a strip 12 extending integrally from the ring, this article having a slit or gap 14 that is opposite strip portion 12. A hole 16 is provided in strip 12, screw-threaded as illustrated. The ring forms a contact for a fuse in a fuse holder. This ring is to be forced into an opening whose diameter is less than the ring diameter, and snaps below an overhang so as to be fixed in position. During this inserting operation, the gap 14 is reduced and the inherent resilience of the ring 16 causes the ring to resume the shape illustrated, becoming self-locked in position. The strip 12 is bent to meet the requirements of the fuse holder.

If such a part were to be stamped from sheet-metal as is readily feasible, the hole left by piercing a disc from ring 1% would represent considerable waste, and the cost of this article would be unduly high. In accordance with the present invention, a method is provided which avoids most of this waste.

As illustrated in FIGS. 3 and 4, a series of parts 2% are stamped out of sheet-metal stock 18. The strips 12 are shown disposed within the rings it) in the relative positions they occupy in the stamping operation. There is no wasted disc within ring 10. However, the width of strip 12 is considerably greater than would normally be available at gap 14; and for this reason the edges 14' of ring it) are spaced apart much greater during the stamping operation than would be permissible in the finished product. Either prior to or during the blanking operation, or immediately after the blanking operation with the portions of ring ill fixed in the relative positions illustrated, dimples 22 are formed in the sheet-metal remote from edges 14', these dimples being of greater extent at the outside edges of ring 10 than at the inner edges of that ring.

Subsequently, handling parts 2% individually so that the space between edges 14'14 is left vacant, dimples 22 are flattened. This has the efiect of closing the wide space between edges 14 as illustrated in FIG. 3 so that they assume the required spacing in FIG. 1.

It is evident that the described illustrative embodiment of this invention is readily adaptable to articles of various shapes, and therefore the invention should be broadly construed in accordance with its full spirit and scope.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. The method of making an article having a split ring and a strip extending integrally from the ring from a length of sheet-metal stock material, the split in the ring being narrower than the width of the strip, including the steps of blanking and forming the strip and split ring with dimples therein, the split in the ring portion being large enough to provide material for the strip portion of another like article to be blanked from the sheet-metal stock, and with the dimples in said ring portion being at points remote from the edges of the split, the dimples being deeper at the outside edges of the ring than at the inside edges of the ring, and thereafter flattening the dimples to reduce the width of the split to the required size.

2. The method of making an article having a split ring provided with an inner and an outer periphery and a strip extending integrally from the outer periphery of the ring from a length of sheet-metal stock material, the split in the ring being narrower than the width of the strip, including the steps of blanking and forming the split ring with dimples therein, the split in the ring portion being large enough to provide material for the strip portion of another like article to be blanked from the sheet-metal stock, and with a plurality of the dimples spaced along the outer periphery of the ring, the dimples being deeper at the outer periphery of the ring than at the inner periphery of the ring, and thereafter flattening the dimples to reduce the width of the split to the required size.

Lang a Aug. 21, 1945 Engel Dec. 13, 1949

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