US3135313A - Apparatus for forming sheet metal - Google Patents

Description

June 2, 1964 L. L. HOCK 3,135,313

APPARATUS FOR FORMING SHEET METAL Filed June 23. 1961 2 Sheets-Sheet 1 INVENTOR. LAWRf/VC L. H

ATTORNEYS June 2, 1964 L. 1.. HOCK 3,135,313

APPARATUS FOR FORMING SHEET METAL Filed June 23, 1961 2 Sheets-Sheet 2 INVENTOR.

' AAWR /WEL Hoax A TTORNEVS United States Patent H 3,135,313 APPARATUS FOR FORMING SHEET METAL Lawrence L. Hock, Snyder, N.Y., assignor to Niagara Machine & Tool Works, Bufialo, N.Y. Filed lune 23, 1961, Ser. No. 119,091 7 Claims. ((11. 153-21) This invention relates to a method of and apparatus for forming sheet metal parts by a succession of metal bending or forming steps carried out by successive strokes of a press brake or other power press provided with a single set of complementary punch and die members.

The method and apparatus of the present invention is directed primarily to the manufacture of a particular sheet metal product but one which is usually and customarily manufactured locally on a relatively small scale.

These articles are known in the art as standing S-cleats and are employed by sheet metal Workers mainly in joining square or rectangular duct sections in end to end relation.

Various economic factors dictate the general practice of manufacturing S-cleats on a relatively small scale local basis. In any event, presently known and used prior art methods generally entail a series of die forming operations performed in a series of different dies which methods involve multiple setting-up operations, multiple handling of the work pieces, and other inefiiciencies, not to mention the cost of the several separate sets of dies required to perform the successive forming steps of such prior art methods.

The present invention provides a punch and die construction and a novel method of employing the same whereby a workman merely places the workpiece successively in various positions in a single die structure and effects successive identical strokes of the press brake or other power press to perform a series of bending or forming operations without any change in dies, set-up, press stroke or any other condition of adjustment or operation.

The workman picks up a rectangular blank of flat sheet metal or analogous material, subjects the same to various bending or forming operations by successive strokes of the press, in the present instance five such strokes, and lays aside the finished standing S-cleat. Furthermore, the cooperating punch and die members disclosed herein for effecting the novel method of the present invention are extremely simple as to the profiles or configurations of the complementary punch and die surfaces.

' Since the standing S-cleats produced by the present method and apparatu are of random length and the forming affects only the transverse cross section of the workpiece, the work is usually performed in press brakes and the punches and die are merely continuous integral bars formed with the desired complementary forming surfaces, as is generally the case in punches and dies employed in press brakes.

A single specific die and punch structure and a specific succession of forming steps are illustrated in the accompanying drawings and described in detail in the following specification by way of example but it is to be understood that the principles of the present invention are not limited precisely thereto nor otherwise than as defined in the appended claims.

In the drawings:

FIG. 1 is a transverse cross-sectional view through one form of a pair of cooperating punch and die members of the present invention with the punch raised and a workpiece in position for a first forming operation;

FIG. 2 is a View similar to FIG. 1 but showing the punch in lowered position wherein the first forming operation has been effected;

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FIGS. 3, 5, 7 and 9 are similar to FIG. 1, showing the punch member in raised position but showing workpieces disposed for a series of subsequent forming operations; and

FIGS. 4, 6, 8 and 10 are views similar to FIG. 2, showing the punch member in lowered position with respect to the die member and showing the completion of such subsequent series of forming operations.

Like characters of reference denote like parts throughout the several figures of the drawings and the specific arrangement and contours of the punch and die members will now be described. Referring particularly to FIG. 1, a die member 15 is provided with a V groove 16 in its upper surface. In the illustrated instance the rear surface of the V groove is more vertically disposed than the front surface, as clearly depicted in the drawing.

The fiat upper portion of the die surface rearwardly of the V groove 16, designated 17, is sloped slightly so that the same is substantially at a right angle to the rear surface of the V groove 16. The front top surface of die block 15 forwardly of V groove 16 may be generally horizontal, as shown.

The punch member is designated 20 and is provided with a V formation 21 which is complementary to the V groove 16. The under surface of punch member 20 just rearwardly of the V formation 21, designated 22 in FIG. 1, is at right angles to the rear surface of V formation 21 and is consequently parallel to the upper rear surface 17 of die block 15. Rearwardly of the surface 22 punch member 20 is offset to provide a further surface 23 at right angles to the rear surface of V formation 21 and parallel to the surface 22 of the punch memher.

As shown in FIG. 2, the punch and die members 20 and 15 may be provided with conventional tongues designated 25 and 26 respectively for securing the punch and die members in a conventional press brake or like power press. The foregoing relatively simple punch and die set-up is adapted to perform, in the present instance, a series of five successive bending or metal-forming operations on a single workpiece With a single handling thereof and without any change in set-up to produce a finished S-cleat such as is shown at 28 in FIG. 10.

These successive operations are performed by successive press strokes and despite the differing character of the successive bending operations the design and arrangement of the punch and die members is such that the various operations are each performed with like strokes of the punch member. That is, the punch member descends a constant fixed distance into the die member on each stroke so that a workman need only successively reposition the workpiece between each bending or forming operation until the five operations of the present set-up have been performed and the finished piece produced.

It is to be understood that S cleats are generally elongated and of various lengths and that the several crosssectional views thereof shown herein are transverse. Accordingly, FIG. 1 shows a rectangular blank or workpiece 30, the width or smaller dimension thereof being shown in FIG. 1 in the initial position of the blank for the first forming operation.

The proportions of the V groove 16 and complementary V formation 21, their relative positions considered from front to rear (from left to right as viewed in FIG. 1), and the depth of travel of the punch member 20, are all such that in the lower or closed position of the punch member the rear or left-hand face of the V formation 21 as viewed in the drawings and the corresponding left-hand or rear face of the groove 16 are parallel and spaced approximately a metal thickness whereas the front or right-hand faces of the groove 16 and V formation 21 are likewise parallel but at a substantially greater distance from each other. Furthermore, the ledge 22 of the punch member 2b is arranged to approach the corresponding upper face portion 17 of die member 15 to within substantially one metal thickness when the punch is in its lowermost position.

In the first operation as shown in FIG. 2, an oblique flange 31 is formed along one edge of workpiece 30, the internal radius of the flange being of course determined by the radius of the apex of the ridge or V formation 21 of the punch member.

The workman then places the flanged workpiece 34 in the position shown in FIG. 3 and because of the relative spacing of the front face of ridge formation 21 and the corresponding surface of V groove 16, a subsequent press stroke produces a rounded return bent formation, as clearly illustrated in FIG. 4.

The operation illustrated in FIGS. 5 and 6 is substantially the same as that of FIGS. 1 and 2 excepting that the opposite edge of the blank or workpiece 3% is obliquely flanged as at 35 and in the present instance in the opposite direction.

In the succeeding forming operation illustrated in FIGS. 7 and 8 the workpiece is formed into substantially Z shape and at the same time the oblique flange 35 is formed into return bent form, again somewhat rounded as in the case of the return bent formation of flange 31, in this instance by reason of the relative spacing of the surface 23 of the punch member with respect to the companion surface 17 of the die block 15.

The generally 2 form of the workpiece produced as illustrated in FIG. 8 provides a right-angle bend at the upper rear edge of the V groove 16 which produces substantially the finished form of a medial flange 37 of the finished S cleat, as shown in FIG. 10. At the same time the apex of the ridge formation 21 of the punch member produces an acute angle formation which is placed in position with respect to die block 15, as illustrated in FIG. 9, whereby a subsequent downward movement of punch member 20 produces a further return bent formation to produce the substantially T form of the finished S cleat illustrated in FIG. 10.

Here again the spacing of the front face of ridge formation 21 of punch member 20 and the corresponding front face of V groove 15 in die block 15 results in a rounded edge in the return bent formation. The front face of punch member if) is notched at the base of the V formation 21 to clear the workpiece as the same flanges up in the various operations and to provide a ledge 38 which, in the final forming operation illustrated in FIGS. 9 and 10, engages the return bend which was formed in the operation illustrated in FIGS. 1 and 2 and holds the workpiece against slipping upwardly during the final forming operation illustrated in FIG. 10. The finished S cleat is thus provided with three smoothly rounded edges which by reason of their mode of formation are of substantially the same radius or thickness across the aforesaid return bends. I

I claim: H

1. In a die for forming metal sheets, a die member having an upper surface portion with a V groove therein,

a punch member generally complementary to said die surface having a V formation adapted to enter the V groove of said die member, said members being so proportioned that in closed position the complementary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced a distance greater than twice said sheet thickness throughout the entire depth of said V groove, the surfaces of said members rearwardly of said V groove and V formation being parallel to each other and at right angles to the rear surfaces of said V groove and V formation.

2. In a die for forming metal sheets, a die member having an upper surface portion with a V-groove therein, a punch member generally complementary to said die surface having a V formation adapted to enter the V groove of said die member, said members being so proportioned that in closed position the complementary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced a distance greater than twice said sheet thickness throughout the entire depth of said V groove, the surfaces of said members rearwardly of said V groove and V formation being parallel to each other and at right angles'to the rear surfaces of said V groove and V formation and proportioned to be spaced substantially a sheet thickness when said members are in closed position.

3. In a die for forming metal sheets, a die member having an upper surface portion with a V groove therein, said upper surface portion rearwardly of said V groove being substantially at right angles to the contiguous rear wall of said V groove, a punch member generally complementary to said die surface having a V formation adapted to enter the V groove of said die'member, said members being so proportioned that in closed position the complementary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced a distance greater than twice said she'et'thickness throughout the entire depth of said V groove, the surfaces of said punch members rearwardly of said V formation being parallel to the aforesaid rear upper surface portion of said die member and spaced therefrom substantially a sheet thickness when the members are in closed position.

4. In a die for forming metal sheets, a die member having an upper surface portion with a V groove therein, a punch member generally complementary to said die surface having a V formation adapted to enter the V groove of said die member, said members being so proportioned that in closed position the complementary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced a distance greater than twice said sheet thickness throughout the entire depth of said V groove, the surfaces of said members rearwardly of said V groove and V formation being parallel to each other and at right angles to the rear surfaces of said V groove and V formation and proportioned to be spaced substantially a sheet thickness when said members are in closed position, one of said last mentioned surfaces being stepped rearwardly to provide a rearward space substantially greater than said sheet thickness space.

5. Apparatus for forming sheet metal articles comprising stationary means and means movable toward and away from the same, said stationary means including a die member having a surface portion. with a V-groove therein, said movable means including a punch member having a V formation adapted to enter the V groove of said die member, said members being so proportioned that in closed position the complementary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced a distance at least twice said sheet thickness throughout the entire depth of said V groove.

6. Apparatus for forming sheet metal articlescomprising stationary means and means movable toward and away from the same, said stationary means including a die member having a surface portion with a V groove therein, said movable means including a punch member having a V formation adapted to enter the V groove of said die member, said members being so proportioned that in closed position the complemetary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced at distance at least twice said sheet thicktherein, said movable means including a punch member having a V formation adapted to enter the V groove of said die member, said members being so proportioned that in closed position the complementary rear surfaces of said V groove and V formation are parallel and spaced by substantially the thickness of a sheet to be formed therein and the complementary front surfaces are parallel and spaced a distance at least twice said sheet thickness throughout the entire depth of said V groove, the surfaces of said members rearwardly of said V groove and V formation being parallel to each other and substantially at right angles to the rear surfaces of said V groove and V formation and spaced substantially a sheet thickness when said members are in closed position, one of said last mentioned surfaces having an offset portion spaced rearwardly of said V groove and formation to provide forming surfaces spaced at least twice said sheet thickness.

References Cited in the file of this patent UNITED STATES PATENTS 658,077 Thomas Sept. 18, 1900 1,963,853 Jones June 19, 1934 2,383,133 Kost Aug. 21, 1945 2,821,234 Robbins et al Jan. 28, 1958 2,847,052 Hardman Apr. 12, 1958 2,908,315 Hellwig Oct. 13, 1959 3,034,559 Slater May 15, 1962 OTHER REFERENCES Cincinnati Press Brake Dies, Catalog D-3, page 17, The Cincinnati Shafer Co., Cincinnati, Ohio.

Claims (1)

1. IN A DIE FOR FORMING METAL SHEETS, A DIE MEMBER HAVING AN UPPER SURFACE PORTION WITH V GROOVE THEREIN, A PUNCH MEMBER GENERALLY COMPLEMENTARY TO SAID DIE SURFACE HAVING A V FORMATION ADAPTED TO ENTER THE V GROOVE OF SAID DIE MEMBER, SAID MEMBERS BEING SO PROPORTIONED THAT IN CLOSED POSITION THE COMPLEMENTARY REAR SURFACES OF SAID V GROOVE AND V FORMATION ARE PARALLEL AND SPACED BY SUBSTANTIALLY THE THICKNESS OF A SHEET TO BE FORMED THEREIN AND THE COMPLEMENTARY FRONT SURFACES ARE PARALLEL AND SPACED A DISTANCE GREATER THAN TWICE SAID SHEET THICKNESS THROUGHOUT THE ENTIRE DEPTH OF SAID V GROOVE, THE SURFACES OF SAID MEMBERS REARWARDLY OF SAID V GROOVE AND V FORMATION BEING PARALLEL TO EACH OTHER AND AT RIGHT ANGLES TO THE REAR SURFACES OF SAID V GROOVE AND V FORMATION.

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