US1660493A - Method of making articles - Google Patents

Description

Feb 28, 192s; I 1,660,493

R. V. PRQCTOR METHOD OF MAKING ARTICLES Filed March 28, 1925 i V I b 1111111111 A, w

5 u f; 1NVENTO wwmQ y @w Patented Feb. 28, 1928.

UNITED STATES PATENT OFFICE.

ROBERT V. PROCTOR, OF YOUNGSTOWN, OHIO, ASSIGNOR TO THE COMMERCIAL SHEAR- ING & STAMPING COMPANY, OF YOUNGSTOWN, OHIO, A CORPORATION OFOHIO.

'unrnon or MAKING An'rrcLns.

Application filed March 28, 1925. Serial No. 19,015.

The present invention relates broadly to metal working, and more particularly to metal bending and shaping as adapted to the formation of sheet metal pallets suitable for manufacture of blocks, brick and th At the present time there is a growing demand for metallic pallets to replace wooden pallets of the type heretofore extensively used. Wooden pallets have obviously been objectionable, not only due to the thickness required in order to give the desired strength, but also by reason of the warping and cracking under successive ap- 1 plications of pressure in the presence of moisture and drying either by-steam or otherwise.

In the manufacture of metallic pallets requiring a flat upper surface, it has been found necessary to provide depending stiffening flanges in order to impart the desired strength to the pallets, and also to prevent twisting thereof along-the diagonals with consequent damage to the article supported thereon.

Due to the construction of molds'and the equipment with which the pallets are used, it is necessar to provide pallets having exceptionally s arp corners at the junction of the reinforcing sides with the main body. As fairly heavy gauge material must be used for the manufacture of said pallets, the problem of forming said corners has not heretofore been successfully solved, thereby preventing the'extensive adoption of pallets of this character.

The present invention has particularly for its object an improved method for the successfulmanufacture of pallets of the charac' 4o ter herein referred to, with down-turned flanges on opposite sides, and in which the top corners ave extremely small radii a proximating right angles. I have found in actual practice that when using sheet metal substantially in thickness, such as ordinarily require a radius of approximately it is possible in accordance with the present invention to produce a corner havmg a maximum radius of In the accompanyin drawings there are shown for purposes of lllustration only, certain preferred embodiments of the present invention, it being understood that the drawings do not define the limits of my invention,

as changes in the construction and operation disclosed therein may be made without departing either from the spirit of the invention or the sco e of my broader claim.

In the draw1ngs- Figure 1 is a perspective view of a completed pallet constructed inaccordance with the present invention;

Figure 2 is a perspective view of a preliminarily shaped blank adapted for the production of the pallet shown in Figure 1;

Figure 3 is a transverse sectional View through a pair of shapingdies illustrating a preliminarily shaped blank in position therebetween; and

Figure 4 is a view similar to Figure 3 illustrating the dies at the completion of their shaping movements.

In carrying out the present invention I provide a sheet metal blank of the dimensions required-for the production of a pallet of the desired size. The blank is then subjected to a forming operation of any desired character to impart-thereto substantially the shape illustrated in Figure 2. Such a'preliminary shaping produces an upwardly curved base portion 2 and outwardly and upwardly diverging sides 3, the bottom and sides being joined by corners 4 of relatively great radii. Such a blank can be easily produced in dies, or by rolling where quantities of the same dimensions are being manufactured.

This preliminarily shaped blank is-adapted to be subjected to a second shaping operation to produce a pallet as shown in Figure 1. This second sh'aping operation is preferably accomplished by the use of dies insurin the necessary pressure to impart the desired characteristics to the pallets.

In Figure 3 I have illustrated a pair of dies comprising a female die 5 and a male die 6, the cooperating portions of the dies being shaped to provide a forming cavity having exactly the dimensions of a finished pallet. When the dies are in space relation, a preliminarily shaped blank is inserted in position in the cavity in the female die as illustrated in Figure 3. This die has extremely sharp interior angles 7 adapted to form the top corners 8 of a finished pallet. The corners 9 of the male die may also be sharp, but this is not essential. These corners may be slightly rounded, if desired, in order to facilitate the movement of the. male die relatively to the blank. After no the blank is in position, the dies are brought together whereby the projection 10 engages the upwardly curved base 2 of the blank and tends to flatten it. This causes the edges 3 to assume a more nearly vertical position, and at the same time tends to produce a flowing of the metal, the amount of flow depending on the overall width of the curved base 2 as compared to the width of the cavity in the female die.

Continued movement of the dies brings the shoulders 11 of the male die into engagement with the upstanding edges 3 and prevents any upward flow of the metal therein. As the dies approach their closed posi tion, illustrated in Figure 4,. there is a down pressure on the center of the blank, as represented by the arrow 12. This pressure, being resisted .by the bottom of the die, resolves itself into a lateral component as indicated by the arrows 13. The sides of the die cavity prevent spreading of the blank such as would result from the lateral com an angular component indica ed by the arrows 15, and substantially intersecting the corners of the female die cavity. This action insures flowing of the metal of the blank into the corners to completely fill the same,

thereby insuring the production of extremely sharp corners of the order of the corners of the die cavity.

In accordance with the present invention I am able to produce a pallet of the character shown in Figure 1, having a flat forming surface 16, and projecting side flanges 17 which join the forming surface with sharp corners 8.

The advantages of the present invention arise from a method of producing a pallet from sheet metal of the desired thickness having reinforcing side flanges joined to the main body of the pallet with sharp corners.

I claim:

In the method of making rectangular flanged articles, the steps consisting in preliminarily shaping a flat sheet of metal to produce a blank having a curved body portion with diverging flanges joined thereto by corners of appreciable radius, pressing the body portion to cause the inner portions of the flanges to move away from each other, and then subjecting the sides of the flanges to pressure while both sides of the body are maintained under pressure to cause a flow of the metal and secure sharp corners at the junction of the body and the flanges.

In testimony whereof I have hereunto set my hand.

ROBERT V. PROCTOR.

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