US1608542A - Spring-clip blank and method of making the same - Google Patents

Description

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Nov.

Nov. 30 1926.

1,608,542 W. P. WITHEROW SPRING CLIP BLANK AND METHOD oF MAKING THE SAME Filed April 7, 1922 3 Sheets-Sheet 2 IN ENT`OR Patented Nov. 30, 1926.

UNITED ISTATES .1,608,542 PATENT OFFICE.

WILLIAM P. WITEBOW', 0F PITTSBURGH, PENNSYLVANIA. ASSIGNOR Tp WITHEROW STEEL COMPANY, OF NEVILLE ISLAND, PITTSBURGH, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA,

SPRING-CLIP BLANK AND METHOD OF MAKING THE SAME.

Application led April 7,

The present invention relates broadly to metal working and more partlcularly to a metal rolling process for the making of structures having U-bolt characteristics such as spring clips and shackles.

It has heretofore been customary to form structures of this general nature by forging. Where such articles are formed entirely by a forging operation, it will be apparent that portions of the metal are subjected to a considerable strain, thereby greatly weakening the finished article. In addition to this, the production by forging methods 1s necessarily more or less limited, and the overhead due to high maintenance of forging hammers is excessive.

This invention relates to the production of articles of this nature by die-rolling whereby production is increased, the cost decreased and the strength of the articles increased. For sake of conciseness the term spring clips will be used throughout the specification and claims but this expression is inclusive of U-bolt structures of this general nature adapted for general use, or use as spring clips or shackles. n

In the accompanying drawings there 1s illustrated one embodiment of the present invention, but it will be understood that changes may be made in the construction and operation disclosed herein without departing from the spirit of the invention or scope of my broader claims.

In the drawings,-

Figure l is a side elevation of a portion of a series of connected blanks produced by die-rolling;

Figure 2 is an edge view of the blank illustrated in Figure 1;

Figure 3 is a view corresponding to Figure 2 illustrating a slightly modified form of blank;

Figure 4 is a side elevation of a single spring clip blank having the flash removed therefrom;

Figure 5 is an edge view of the construction illustrated in Figure 4;

Figures 6, 7 and 8 are views of one form of a spring clip produced in accordance with the present invention;

Figures 9, 10 and 11 are transverse sectional views on the lines III-IX, X--X and XI-XI, respectively, of Figure 6;

Figure 12 is a sectional view through one 1922. serial No. 550.1523.l

form of rolls for carrying out the present invention. A

The present invention is preferably carried out by producing a billet or leader having a cross sectional area substantially equal to the maximum cross sectional area of a finished spring clipvto be produced therefrom. By utilizing such a leader, work of the die-rolls is minimized and the cost of upkeep as well as the cost of operation is decreased. This leader may be heated to the desired temperature and then subjected to the rolling operation. In Figure 12 there is illustrated one form of die-rolls for this purpose, comprising a mandrel 2 adapted to supporta series of segments 3 of any desired construction, having formed therein shaping grooves 4 or projections 5. The diameter of the rolls preferably bears a definite relationship to the length of a spring clip blank to be produced whereby the rolls may carry a recurrent pattern for forming a series of clips lat each revolution thereof.

In Figures l and 2 of the drawings there is illustrated a portion of a connected series of blanks as produced by the rolls illustrated in Figure 12. Each of the blanks comprises leg-forming portions 6 extending in substantially longitudinal alignment and connected by angular offsets 7 with a saddleforming portion 8. An excess of metal may be provided in the leg-forming portion 6 with respect to the length thereof to allow -ior cutting or trimming for separating the individual blanks as illustrated by chain lines in Figures 1 and 2. In some cases it may be desirable to connect adjacent legforming portions 6 with a gating 9, as illustrated in Figure 3. Where such a gating is utilized, it will be apparent that it provides a bite for the rolls insuring proper gripping of the leader.

As before stated, the leader preferably has a cross sectional. area which is substantially equal to the maximum cross sectional area of a finished spring clip. This maximum area is located in a transverse plane passing through the angular osets 7, so that at these points there is substantially no re duction of the leader. Throughout other portions of the blank provision is made for a flash l0, the depth of which corresponds to the reduction which takes place during the die-rolling operation. The die-rolls have been found to produce advantageous results when shaped to form curved saddle-forming portions 8, as illustrated, and to form initial interior angles 11 which are substantially right angles, as Will be more fully pointed out hereinafter.

After the blanks are separated into individual units they are suitably machined or pressed to square the ends 12 and remove the flash 10, as illustrated in Figures 4 and 5. The leg-forming portions are preferably so rolled as to provide a lower cylindrical portion connected to the upper part, Which may be generally semi-cylindrical in cross section, by a shoulder 13. These leg-forming portions may then be suitably machined to reduce the diameter of the lower parts thereof and remove the shoulder 13 on the inner side of the blank. This removes the skin or outer surface of the blank and provides a solid portion adapted to be threaded in any desired manner. Either before or after the threading operation the blanks may be bent fromvthe form shown in Figures 4 and 5 to the form illustrated in Figures 6, 7 and 8.

The bending of the blank into its finished form is greatly facilitated by reason of the fact that the interior angles 11 are initially formed. This makes it unnecessary to redistribute the metal at these points during the bending operation, whereby the strain to which the metal body of the clip is subjected is minimized. The same is true of the offsets 7 as these offsets provide a surplus of metal permitting the formation of full corners Wi hout materially stretching the fibres adjacent the corner portions of the clip. This strain Will be substantially uniformly distributed throughout the j major part of the saddle-forming portion and in the upper parts of the leg-forming portions. It Will be obvious that due to the minimization of the strains in the finished clip that a stronger article is produced than can be produced by a forging operation.

The advantages of the present invention arise from the provision of a method by means of which uniform articles of this nature can be more expeditiously and less expensively produced.

Further advantages arise from the provision of a finished spring clip in which the strain is minimized and maximum strength insured. f

I claim:

1. In the method of forming spring cli the steps consisting in die-rolling a leadesr to form interior angles and to provide a surplus of metal adjacent each of said angles, and then bending the same to cause interior angles to form the inner corners of the finished clips, substantially as described.

2. In the method of forming spring clips, the steps consisting in flowing .successive portions from end to end of a blank to produce an article having interior angles of substantially 90, and having a surplus of metal opposite each of the angles, substantially as deszfribed.

3. As an article of manufacture, a die rolled spring clip blank having substantially straight leg forming portions of generally circular cross section and a curved saddle forming ortion of different cross section, said leg orming portions extending substantially in longitudinal alignment with each other and being connected with said saddle forming portion by angular offsets, substantially as described.

4. As an article of manufacture, a strin of die rolled spring clip blanks arrange end to end, each blank comprising leg form- .mg portions and an intermediate saddle forming portion, the adjacent legfforming portions of adjacent blanks having an integral flash extending along both of said adjacent leg forming portions, substantially as described.

5. As an article of manufacture, a string of die rolled spring clip blanks arranged end to end, each blank comprising leg forming portions and an intermediate saddle forming portion, the adjacent leg forming portions of the blanks having an integral fiash extending along both of said adjacent leg forming portions, the adjacent spring clip blanks being separated by a gating, the flash extending across the gating, substantially as described.

In testimony whereof I have hereunto set my hand.

WILLIAM I. VITHEROW.

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