US1815102A - Machine for bending sheet metal - Google Patents

Description

July 21, 1931. M. I HNRICH MACHIHNEIEFOR BENDING SHEET METAL Filed March 17, 1950 2 Sheets-Sheet 1 ATTORNEYS Patented July 21, 1931 I 1 UNITED STATES PATENT OFFICE;

ROBERT M. HINRICH, or DETROIT, MICHIGAN, ssrenon To DRAKE-AVERY COMPANY,

013 DETROIT, MICHIGAN, A CORPORATION or: MICHIGAN MACHINE FOR BENDI SHEET TAL,

The invention relates to machines for bending sheet metal of the general type known as brakes. It is the object of the invention to obtain a construction which is particularly designed for the forming of a type of oint or seam extensively used in sheet metal construction and to accomplish this with the elimination of a number of operations necessary with brakes of ordinary construction. To this end the invention consists in the novel construction as hereinafter set forth.

In the drawings:

Figure l is an end elevation of a brake to which my improvement is applied;

Figure 2 is a front elevation of a portion of Figure 1;

Figure 3 is a cross section;

Figure 4 is a similar View showing the parts in different positions;

Figures 5 and 5a are cross sections showing the successive operations with my improved machine;

Figures 6, 6a, 6b, 60, 6d and 6e are cross sections showing the successive operations usually performed for forming the same joint by an ordinary construction of brake, and

Figure 7 is a section similar to Figure 3 showing a modified construction.

The general construction of my improved brake may be of any suitable design as hereinafter set forth. It comprises essentially a bed or table A having a depending front flange B and a movable jaw or clamp O which is raised or lowered by any suitable means such as the lever D and eccentrics E. F is a bending leaf which normally lies parallel to the flange B and which is pivoted at G in alignment with the corner at the intersection of the table A and flange B.

The parts thus far described are common to other constructions of brakes and may be used for forming various constructions of joints by a series of distinct bending operations. Thus Figures 6 to 6d inclusive show the successive operations for forming one type of joint as follows: In Figure 6 the sheet metal blank 1 clamped by the member C has a flange 2 bent at right angles through the raising of the leaf F. By a distinct operation shown in Figure 6a a portion 3 of the flange 2 is bent at right angles to form a Z-shaped construction. By a third operation shown in Figure 6b the portion 2 is bent at an acute angle to the portion 1 and by a succeeding operation Figure the portion 3 is bent at an acute angle to the portion 2. By

a fifth operation, Figure 6d, the structure is flattened down to form return bends 4f and 5 and by a sixth operation Figure 6c the por-. tion 1 is pressed up into the plane of the portion 3. p

To avoid the necessity of performing all of these successive operations, I have designed a construction in which with only two. operations the: joint is completely formed. This asshown' in Figure 3 comprises a member H which may be laid upon the bed A to raise the level thereof but terminating short of the front flange B to form by the bed a lower step I, The leaf F has attached to its front face an upwardly projecting flange J and'the clampingmember C has attached to its outer face a step K with a downwardly projecting flange L. The arrangement is such that by first placing the sheet metal blankupon the bed and clamping the same by the member Cwith aportion projecting outwardly, the wing F may then be swung upward. into the position shown in Figure 4. This bends the metal into av Z-shaped form with two acute angle bends, one formed aroundthe edge of'the clamping member 6' and the otherby the co-operation of. the projecting flanges J andL together with the step K. At-the completion of. this operation the clamp is released, the leaf-F lowered and the blank with the z-shaped bend therein ismoved inward so as to bebeneath the raised clamp C; This clamp is then lowered into theposition shown in Figure 3 where the Z- shaped bend is flattened. down into the re-. cess formed by the step I, forming the structure as shown inFigure 5a. Thus completed structure includesthe two portions M andM which are arranged in the same plane and the reverse return bent portions M and M the latter being off-set as shown.

In the modified construction shownin Figure 7', the onlydifl'erence, is the placing of a proj eating-portion N. ontheclamping member C which registers with the recess formed by the step I. With this structure when the sheet metal blank is first clamped by the depression of the member 0 it will simultaneously form an off-set portion between the projection N and the step I. The leaf F is then swung upward to bend this offset portion into the Z form, after which the clamp is released, the Z-shaped portion is moved inward beneath the portion I and the clamp is again depressed to flatten down the bend. In other words, in the construction shown in Figures 3 and 4 the off-set is formed in the final operation whereas with the construction shown in Figure 7 the off-set is formed in the initial operation but the final structure is the same in each instance.

My improved machine will greatly expedite the forming of the seam and thus will considerably reduce the cost of the labor.

IVhat I claim as my invention is:

1. A sheet metal brake comprising a bed, a clamping head above said bed having an acute angular edge portion, a swinging leaf for bending a projecting portion of a blank clamped by said head and bed over said acute angular edge, co-operating means on said swinging leaf and said head for forming a reverse acute angular bend in said blank and a raised portion on said bed for supporting the blank removed from the edge to form a recess into which said reverse acute angular bends may be collapsed by the clamping pressure of said head to form in said blank an offset double return bend.

2. A sheet metal brake comprising a bed, a clamping head having an acute angular edge portion, a swinging leaf pivoted on an axis adjacent to said acute angular edge, an acute angular bent edge carried by said leaf for engaging a projecting portion of a sheet metal blank clamped by the said head and bed to bend the same over said first mentioned angular bending edge, and a member on said clamp co-operating with the acute angular bending edge on said leaf for forming a reverse acute angular bend in said blank and a raised portion on said bed for supporting the blank removed from the edge to form a recess into which the reverse acute angular bends in said blank may be collapsed to form in said blank a laterally off-set double return bend.

3. A sheet metal brake comprising astepped bed, a clamping head extending over the step in said bed and provided with an acute angular edge portion, a swinging leaf pivoted upon an axis adjacent to said acute angular edge, an acute angular edge portion carried by said leaf and adapted to bend a projecting portion of a sheet metal blank clamped by the said head and bed about acute annular edge on said head, a member projecting from said head,fco-operating with the acute angular edge portion on said leaf for forming in saidblanka reverse acute angular bend

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