US3503245A - Method and apparatus for removing defects from sheet metal - Google Patents

Description

March 31, 1970 B. BRANDL 3,503,245

METHOD AND APPARATUS FOR REMOVING DEFECTS FROM SHEET METAL Filed Oct. 4, 1967 2 Sheets-Sheet l I I P W" E q /Z FIG 2 INVENTOR BEN BRANDL ATTORNEYS March 31, 1970 B. BRANDL 3,503,245

METHOD AND APPARATUS FOR REMOVING DEFECTS FROM SHEET METAL Filed Oct. 4, 1967 2 Sheets-Sheet 2 FIG. 3

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INVENTOR BEN BRANDL BY @4444, M, Y -5 ATTORNEYS United States Patent 3,503,245 METHOD AND APPARATUS FOR REMOVING DEFECTS FROM SHEET METAL Ben Brandi, Royal Oak, Mich. (233 Kirk Lane, Troy, Mich. 48084) Filed Oct. 4, 1967, Ser. No. 672,875 Int. Cl. B21c 51/00; B21d 11/04, 1/05, 31 /06 US. Cl. 72-340 6 Claims ABSTRACT OF THE DISCLOSURE The method and apparatus for correcting defects, such as gouges, scratches, indentations, scale marks, or coil marks in sheet metal, which would otherwise be scrapped, by locating such defect in the sheet in registry with a hardened steel anvil or hammer; mechanically upsetting the metal to a height at least equal to the depth of such defect, and surface grinding away of excess metal and rolling same to provide a prime sheet.

The present invention relates to a method and apparatus for treating metal sheets, which would normally be scrapped due to gouges, scratches, indentations or other defects in the surface thereof.

It is the primary object of the present invention to provide a practical novel method and apparatus for the saving of steel or other metal sheets becoming scrap, simply because there are defects or indentations in one or more areas thereof. Any type of alloy metal, hot rolled, or cold rolled steel sheets, stainless steel, titanium, aluminum, or any other special alloys including heavy gauge plates of any type metal alloy may be treated by the present method and apparatus in gauges which range from .018" to .750" gauge sheets or three-quarter inch plates.

Such defects or indentations may be in the form of rolled-in scale, coil or friction gouges, deep pits, lamination lines, or any other of the many problems that cause steel or other metal surfaces to be defective.

An object of the present method and apparatus is to save a high percentage of steel, for example, from being rejected or scrapped, where in the present process in using the present apparatus or the equivalent, a prime sheet of metal may be sold at prevailing prime metal prices.

For illustrations, steel warehouses may sell such reject or scrap steel at $60.00 to $70.00 dollars per ton, for example, whereas the same sheet steel as prime steel or rendered prime by the present process will sell for approximately $l40.00 per ton and upwards, for illustration.

In the production of bumper steel at .110" gauge sheets, a defect in the sheet such as a large scale mark or a plurality one-quarter inch round 0A") and .015" deep, normally rejectable as scrap, employing the present process, such scale mark is completely removed and its prior existence will not be recognized.

It is therefore another object of the invention to provide a process which eliminates such defects and at the same time leaves no dents, gouges, or other off-color areas and produces a prime fiat surface.

It is therefore the primary object to provide a method and apparatus for taking metal or steel sheets with defects normally producing scrap, elevating such defects by the up-setting of the metal at such defect to a height at least equal to the depth of the defect or gouge, and thereafter grinding away the excess metal to produce a sheet free of such defect.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawings in which:

FIGURE 1 is a partly schematic and broken away and sectioned side elevational view of a simple form of apparatus for carrying out the present process.

3,503,245 Patented Mar. 31, 1970 FIGURE 2 is a similar view of a modification.

FIGURE 3 is a similar view of another modification.

FIGURE 4 is a block diagram illustrating the steps of the present process.

FIGURE 5 is an elevational view taken from the side of a sheet having a defect which additionally shows the same sheet with the metal up-set at said defect and the same sheet after the up-set excess metal has been removed by a grinding and polishing operation.

It will be understood that the above drawings illustrate merely illustrative preferred apparatus of carrying out the present method, and that other apparatus is contemplated within the scope of the claims hereafter set forth.

Referring to the drawings, and as shown in FIGURE 5, the three illustrations successively show from top to bottom the original sheet of metal S, with small defect or indentation D, which may range in depth from .024" to .050". The second illustration shows the same sheet after the metal thereof has been mechanically up-set by the present process and apparatus at the said defect, whereas the third illustration of FIGURE 5, shows the sheet after the grinding and polishing and rolling operation as a prime sheet with only a tiny indentation in its undersurface, which means nothing and has no effect upon the ultimate usage of the sheet, such as for a plating operation on its top surface, as in the manufacture of bumpers, for illustration.

One form of apparatus for carrying out the present process includes bed 11 mountable upon a floor 12 and having a horizontally disposed table 13. A series of coplanar roller castors are located throughout the top area of the table 13 and are universally movable thereon, adapted to movably support a sheet of metal, as for example the steel sheet S having a defect, such as a gouge, scratch or indentation designated at D.

Centrally disposed upon table 13 and secured thereto is a suitable mounting plate 15 with a bore 16 therethrough.

Hardened steel anvil 17 of a mushroom form, for illustration but which may be of other shapes, such as elongated or oval, is mounted upon the plate 15, and includes a depending shank or bolt 18, which extends through the bore 16 and into a corresponding bore within the table 13 and may be threaded therein as at 19.

Anvil 17 normally lies above the plane of the castors 14 adapted for cooperative registry with the undersurface of the sheet S in registry with defect D.

The light 20 mounted at 21 spaced above table 13, includes a beam 22, which is focused at all times directly upon and in registry with anvil 17. In carrying out the method, such as shown schematically in the block dia gram, FIGURE 4, there may be a preliminary step of flat polishing the metal sheet in order to better bring out and locate the defect, which may be a gouge, scratch or indentation or scale mark, and the same can be marked if desired with a marking crayon for better location. In the locating step of the present method the sheet S is mounted over support rollers 14 and is movably adjusted thereon until the now identified defect is in direct registry with the light beam 22. This guarantees furthermore that the defect is also in direct registry with the hardened anvil 17.

Thereafter the metal is up-set by the application of sufficient transverse pressure to the sheet at the said defect. In the illustrative embodiment in FIGURE 1, the rubber or leather mallet 23 is provided and upon application of a sufiicient blow to the metal at the defect, there will be produced sufficient upset of the adjacent metal to a height at least equal to the depth of the gouge or defect, and this corresponds to the second up-setting of FIGURE 4.

The sheet is then removed from the table and is subjected to a grinding operation in a conventional machine known as an abrasive belt sheet steel or other metal grinder and polisher, which is power operated and which subjects the entire top surface of the sheet as it is fed over rolls to a uniform grinding and polishing operation. Normally there is employed aluminum oxide, cloth or paper belts of a standard length 126", which may have a width as much as 72" for illustration, for the particular grinding and polishing operation. This step concludes one form of the present process to provide a substantially prime sheet of metal and wherein the defect or defects or indentations or gouges have been mechanically removed from the top surface thereof. A further step is contemplated; namely, the rolling step, such as shown in FIG- URE 4, using level rolls for rendering the sheet more fiat. For example, where a pit sought to be removed by the present process if .005" in depth, and the up-set involved is .009" and wherein the grinding and polishing removes only .005, the advantage in the use of the level roller is that it will further flatten and completely correct the sheet metal and thus counteract for any possible excess upsetting as a final step in the sheet metal treating process, as further described in detail hereunder and wherein power operated level rolls are employed.

MODIFICATION NUMBER I Upon a similar bed 11, partly broken away for illustration, having table 13 and castors 14 to support the sheet metal S thereabove, it is noted that at least similar parts of the corresponding apparatus bear the same identification and their description is not repeated in detail. Here the hardened anvil 24, is dome-shaped for illustration, but which could be of other convex shape, has a depending shank or bolt which extends down into the piston rod 26 or may be threaded thereinto for movement with the connected piston 27 within the hydraulic power cylinder or hammer 28, mounted at 29 upon a suitable support within bed 11.

A movable and interchangeable anvil 24 loosely projects up through the bore 30 in table 13 and when activated upwardly through the controls 28', schematically shown, is adapted to operatively engage sheet S at defect D for carrying out the present process. A holddown apparatus is illustrated, which includes a vertically adjustable metal platten 31, normally spaced above table 13, and vertically adjustable thereover, employing hydraulic or pneumatic cylinders 36, with piston rods 38 connected at 39 to said platen, and regulated under controls 37, schematically shown for feed movements towards table 13.

A resilient pressure block of rubber or neoprene of a high durometer in the range of 70 to 90 as designated at 32 and is suitably secured to the undersurface of the platen 31, for cooperative retaining engagement with said sheet before and during the upsetting process.

The platen 31 has a bore 33 therethrough in registry with corresponding bore 34 in the pressure pad 32, by which the light beam 22 as above described, is focusable upon the defect D when the sheet has been transversely moved upon the castors for registry therewith, and assuring registry with and alinement with hardened steel anvil 24, which forms a part of the hydraulic hammer 28, and is removably connected thereto.

It is noted that the undersurface of the pressure pad 32 is slightly concaved as at 35, adapted to receive cooperatively the metal which is up-set, when the hammer 28 is activated.

While FIGURE 1 apparatus does not designate a means for holding the sheet S in position during the upsetting operation, the embodiment of FIGURE 2 being more of a mechanical device illustrates therefore the platen 31 and pressure pad 32 for this purpose.

MODIFICATION NUMBER II Another form of the present apparatus for carrying out the method is shown in FIGURE 3 wherein the hollow bed upon floor 12 includes upright side walls 41 mounting the top guideways 42, receiving the V-shaped guides 44 which depend from table 43 to provide for longitudinal adjustment of the table upon-said bed.

For this purpose a suitable motor 45 is bracketed at 46 to the bed and includes output shaft 47 and sprocket drive 48, which through sprocket chain 49 drives sprocket 50 upon one of a pair of feed screws 51. These screws, suitably supported and journalled upon the bed, are in threaded engagement with nut portions 52, which depend from table 43. The second feed screw 51, FIGURE 3, is connected with the first feed screw by means of an additional sprocket gear set 53, and sprocket chain 54, whereby the feed screws 51 are adapted to rotate in unison in the same directions for effecting feed movement of the table 43 upon bed 40.

Extending transversely of table 43 and formed therein or applied thereto are suitable guideways 55 adapted to supportably receive the transversely adjustable magnetic chuck 56, which supports the sheet S, having a defect D to be removed by the present process.

Suitable magnetic means is schematically shown at 57, connected to a power source and to the magnetic chuck 56, to provide a means for magnetically securing and holding down the sheet S for the upsetting operation. This provides a means by which the' holddown platen 31 and pressure pad 32 of FIGURE 2, and associated mechanism may all be eliminated, and at the same time provide for automatic feed adjustment of table 43, and the transversely adjustable magnetic chuck 56.

Chuck 56 has a central bore 58 of sufiicient size as to receive when adjusted transversely and longitudinally, the hardened steel mushroom-shaped anvil 71, for up-setting defect D in the sheet S, there being a suitable corresponding central bore or recess extending through table 43 to provide suitable clearance.

Motor 59 bracketed at 60, FIGURE 3, provides a power train 61 for driving the feed screw 62, which is journalled at 63 and supported at 64. Said feed screw, of which there may be one or more, threadedly engages the nut 65 on the chuck 56, to thus provide controlled transverse adjustments of said chuck with respect to table 55, and thus providing universal adjustment for the workpiece or sheet S, to thus locate its defect D, so that beam 74 from the light 72 on bracket 73 is in registry therewith.

Since the beam 72 is at all times in registry with and in alinement with the longitudinal axis of the anvil 71, it is assured that once the beam 74 illuminates the defect D, that said anvil will be in the correct relative position for up-setting the metal of the sheet at the defect, such as shown in FIGURE 5.

The present power hammer, identified as a hydraulic cylinder at 67, FIGURE 7, is fixedly secured within bed 40 by suitable brackets 66. The power hammer or cylinder 67 includes reciprocal piston 68 with rod 69 apertured at its upper end to receive loosely or threadedly a depending shank 70 of the hardened steel anvil 71. A suitable manual or other control is schematically shown for regulating and controlling and supplying the pressure fluid for the operation of the pneumatic or hydraulic hammer 67.

In the hand method of up-setting the metal in the apparatus of FIGURE 1, suflicient up-setting pressure is provided by the use of the rubber or leather mallet 23, which is manually operated, and by hitting the defective area D, which is directly under the light beam 22, in turn in registry with the anvil 17, for elevating the defective area D.

A mechanical type of operation is better shown in FIGURES 2 and 3. It is noted in FIGURE 2 that the pressure pad 32 in addition to having a holddown function will during the up-Setting operation permit the defective area to recess into its body, as shown at 35.

After the up-setting operation by any of the apparatus, FIGURES l, 2, and 3, and as shown in the block diagram, FIGURE 4, the sheet of steel or other metal as upset is put through the preadjusted flat polishing machine of a conventional character, and available on the market, by which the elevated up-set area is ground down to the bottom of the defect or indentation. It is contemplated that a disc grinder may also be employed for removing the defect in the elevated area.

In the event the defect be a lamination line or a long handling or mechanical gouge or scratch, then a correspondingly elongated anvil 17 would be employed, which rather than mushroom-shaped will be elongated and convex. The corresponding upset in the steel then would be similarly elongated, but would nevertheless be removed in the grinding and polishing step, FIGURE 4. It is contemplated that a pair of spaced light beams could be employed, so focussed as to register with spaced points upon the elongated anvil employed, and to thus assure that the up-setting of the metal is in registry with the elongated scratch or other defect.

After the grinding operation it is considered a desirable step in many instances to run the sheet through a roller leveller to further assist in restoring the sheet to its original flat shape, and this is particularly true wherein the up-setting operation the height of the upset happens to exceed the depth of the defect or gouge or other indentation.

It is contemplated as a part of the present invention that the present method is applicable to a continuous coil of steel and is not necessarily limited to sheet strips. In this situation a coil of steel as it is partly unwound, or passed over an inspection area, has designated over that portion of the unwound coil the defect area where it is to be up-set by the present method. The defect is then adjusted in registry with the illumination source, and an anvil and an up-setting operation takes place manually or automatically or by power as hereinbefore described, thus up-setting the defect area to a height least equal to the depth of the defect, and thereafter and adjacent thereto, there will be a hand polishing or finish polishing station by hand grinding or with a belt type of grinder through which that portion of the coil passes to thus provide in the completed coil prime material free of defect.

Having described my invention reference should now be had to the following claims. I claim:

1. The method of treating normally scrapped steel or other metal sheets which have surface defects, including indentations, scratches, gouges, or rolled in scale to render the same prime stock, which consists of the following steps:

adjustably positioning such sheet upon a horizontal support and locating a defect therein in registry with a power operated anvil positioned below said sheet;

applying a compressive yieldable holding force to and surrounding the defect top side of said sheet;

upsetting the metal of said sheet at said defect by application of an upward force through said anvil to a height above the top surface of said sheet at least equal to the depth of said defect;

grinding said sheet removing therefrom portions of the elevated metal which include said defect providing a top surface for said sheet free of said defect;

said locating including continuously focusing an overhead beam of light in registry solely with said anvil; and

translating said sheet upon said support so that said beam of light illuminates said defect, thus accurately locating said defect above the hidden anvil.

2. Apparatus for treating normally scrapped steel or other metal sheets which have surface defects, including indentations, scratches, gouges, or rolled-in scale, to render the same prime stock, the improvement comprising:

a bed;

a table thereon having a central bore;

a hardened steel anvil of mushroom shape on said bed and projectable from said table and including a support shank;

coplanar support means movably mounted upon said table adapted to movably mount a metal sheet having an indentation defect in its top surface;

said support means lying in a plane below said anvil when operative;

and a light source spaced from said table having a beam focused solely upon said anvil;

said sheet being movable over said support means for registry of said defect with said beam;

a. power operated cylinder and reciprocal piston rod assembly mounted on said bed with its axis in registry with said light source, said piston rod assembly being connected to said anvil, adapted for operative engagement with said sheet on its under surface at said illuminated defect for upsetting the metal of said sheet at said defect above its normal top surface to a height at least equal to the maximum depth of said defect;

an adjustable hold down means above said table adapted to retainingly engage said sheet;

and apertured therethrough for the passage of said light beam onto said defect.

3. In the apparatus of claim 2, said hold down means including an apertured movable platen;

and a yieldable apertured cushion means upon its under surface for operative engagement with said sheet.

4. In the apparatus of claim 2, said table being movably mounted on ways upon said bed for longitudinal adjustment in one direction;

said support means including a chuck movably mounted on guide ways upon said table for transverse adjustment; and power feed means on said bed for controlling feed movements of said table and chuck in right angularly related directions.

5. In the apparatus of claim 4, a magnetic hold down means incorporating into said chuck for retaining the metal sheet thereon.

6. The method of treating normally scrapped steel or other metal sheets which have surface defects, including indentations, scratches, gouges, or rolled in scale to render the same prime stock, which consists of the following steps:

adjustably positioning such sheet upon a horizontal support and locating a defect therein in registry with a power operated anvil positioned below said sheet;

applying a compressive yieldable holding force to and surrounding the defect top side of said sheet;

upsetting the metal of said sheet at said defect by application of an upward force through said anvil to a height above the top surface of said sheet at least equal to the depth of said defect; grinding said sheet and removing therefrom portions of the elevated metal which include said defect providing a top surface for said sheet free of said defect;

and pressure rolling said sheet at its top and bottom surfaces and further flowing the remaining elevated metal into the body of said sheet to provide a top planar surface.

References Cited UNITED STATES PATENTS CHARLES W. LANHAM, Primary Examiner E. M. COMBS, Assistant Examiner US. Cl. X.R.

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