Title:
Apparatus for rustproofing the cut edges of stamped or punched articles
United States Patent 2263158


Abstract:
This invention relates to the manufacture of .articles stamped or punched from metal stock in sheet or strip form, and more particularly to an apparatus for treating the raw or freshly cut edges of such articles to prevent them from rusting. More or less trouble has been experienced heretofore...



Inventors:
Benton, Arnett E.
Application Number:
US30797139A
Publication Date:
11/18/1941
Filing Date:
12/07/1939
Assignee:
BOND MFG CORP INC
Primary Class:
Other Classes:
118/241
International Classes:
B21D51/44; C23F11/00
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Description:

This invention relates to the manufacture of .articles stamped or punched from metal stock in sheet or strip form, and more particularly to an apparatus for treating the raw or freshly cut edges of such articles to prevent them from rusting.

More or less trouble has been experienced heretofore in the manufacture of stamped or punched articles formed from sheet metal stock since the freshly cut surfaces of the articles are left ex- I posed, thus permitting oxidation to take place and grow into objectionable deposits. This problem is particularly acute in the manufacture of crown caps and similar closures where the closure shell is stamped or punched from sheet I metal stock the surfaces of which have been preliminarily treated with tin, varnish or other protective and decorative coatings.

In the manufacture of crown caps the shearing of the metal stock by the stamping or punching 2 machine leaves at the periphery of the blank a newly cut surface which is wholly unprotected by varnish or other protective coating. These raw edges of the caps tend to oxidize or rust even while the caps are in storage. Bottles capped 2 with closures of this type are often in transit or in storage in the ice box of the retailer or in the home for considerable periods of time and thus the closures are subjected to moist atmosphere under conditions favoring corrosion of exposed metal surfaces. This results in objectionable formations of rust at the raw edges of the cap which as the cap is disposed on the bottle are adjacent and frequently in direct contact with the neck of the bottle. Such rust deposits are hot only unsightly, but there follows from it the further disadvantage that the rust sticks to the neck of the bottle after the cap has been removed. The resulting deposit is not only unsanitary from the standpoint of removing the contents from the bottle, but before the bottle can be refilled, it is also necessary to give the bottle special treatment such as by dipping in a weak acid solution to completely remove the rust.

An object of the invention, therefore, is to provide an apparatus for applying a rust inhibitor to the raw edges of the stamped or punched articles during the stamping or punching operation: Another object of the invention is to provide an apparatus for applying a rust-inhibitor to the newly cut surfaces of blanks cut during the usual steps of cutting and forming crown caps and similar closures without hindering or slowing up the manufacturing operation.

Other objects and features of the invention comprise the provision of apparatus for presenting the rust-inhibiting liquid in cooperation with a stamping or punching machine whereby the Sraw edges of the newly cut articles are effectively and relatively and inexpensively coated with a film of rust-inhibiting liquid.

I accomplish the above objects and features in one form of the invention by providing the o stamping or punching machine with means for applying the rust-inhibiting liquid to a surface of the cutting punch. After the cutting punch has passed through the sheet stock its movement is continued so as to wipe the side walls s of the cutting die, thereby leaving a film of rustinhibiting liquid on the side walls of the die. On the next succeeding cutting stroke of the punch, the blank cut thereby acquires, upon entering the die, a coating of rust-inhibiting liquid on the o raw edges thereof.

In another form of the invention, the cutting die is provided with an annular porous member fitted into the inner side walls thereof, together with means for supplying rust-inhibitki. liquid '- to the porous member for application to the raw edges of the cut blanks as the blanks are forced inwardly of the die into wiping engagement with the annular porous member. As the description proceeds, additional forms of the means for ac3" complishing the invention will become apparent to those skilled in the art, the above forms being presented as illustrative of the invention only.

The above and additional objects and features of the invention will become further apparent upon consideration of the following description when read in connection with the accompanying drawing, in which: Fig. 1 is a vertical sectional view of the cutting and forming elements of a conventional type of bottle cap machine to which one form of the present invention is applied; Fig. 2 is an enlarged view showing in vertical section a portion of a pair of cutting and forming dies similar to those shown in Fig. 1 but provided with a modified form of the present invention; and Fig. 3 is a horizontal sectional view taken along line 3-3 of Fig. 2.

As shown in Fig. 1, the machine includes a base member I0 and an assembly head 12. The base member is provided with an annular cutting die 14, within which is positioned a forming die 16.

The assembly head is provided wth a tubular cutting punch II which is adapted to be vertically reciprocated relative to the cutting and forming dies 14 and 16. Slidably carried within the cutting punch 18 is a forming punch 20 adapted to reciprocate relative to the cutting punch during the cap forming operation. A plunger 21 is located centrally of the forming die 16 to eject the formed cap at the appropriate time.

In the operations of cutting and forming the bottle cap, sheet metal stock 22, which has previously been surface coated with tin, varnish or other protective material, is fed to the base member 10 and positioned over the mouth of the cutting die 14. The cutting punch 18 is forced downwardly against the sheet stock 22 whereby a circular blank 24 is severed by the coactive shearing relation of the punch 18 and the cutting die 14. Directly after the shearing of the blank, the forming punch 20 is forced downwardly relative to the cutting punch 18 to force the blank 24 against the forming die 16. The forming die being annular and provided with an upper shapeforming surface 26 of an appropriate character, the blank is caused to assume the desired form as the forming punch 20 enters the forming die 16.

In order to apply the rust-inhibiting liquid to the freshly cut edges of the cut blanks 24, I have provided in one form of the invention an applicator 30 which is secured to the stripping member 28 of the assembly head 12. The applicator comprises an annular member 32 provided with an inwardly extended flange 34. The annular member 32 is provided with an annular groove 36 in its outer surface adjacent its upper edge.

The outer surface of the member 28 is provided adjacent the lower edge thereof with a similarly shaped annular grooVe 38. A clamping ring substantially U-shape in cross-section and split in semi-circular halves is provided, the flanges which form the legs of the U being received in the goroves 36 and 38 to hold the annular member 32 against the lower edge of the member 28.

The outer surface of the clamping ring is grooved to receive a spring clamp 44, whereby the two sections of the clamping ring are held in securing position. The inner edge of the flange 34 is proportioned for alignment with the inner surface of the member 28 and to slidably engage the outer surface of the cutting punch. The space between the flange 34 and the lower edge of the member 28 is filled with felt or other suitable porous material 46 to which rust-inhibiting liquid is delivered through a conduit 48 from a source of supply, not shown. The liquid may be fed by gravity or, if desired, may be delivered under control of any appropriate pump or valve arrangement. Advantageously, the pump or valve may be operatively controlled by the sheet stock feeding mechanism so as to avoid continued delivery and waste of liquid upon discontinuance of the feeding of sheet stock.

The rust-inhibiting liquid may be a mineral oil or other suitable oil or other liquid possessing rust-inhibiting properties or may comprise any of various commercially available rust inhibitors dissolved or suspended in an oil or other suitable liquid menstruum. Among the rust inhibitors that may be employed either alone or in solution or suspension in a suitable oil or other menstruum are the following: oleic acid, naphthenic and emulsifying oils, palm oil, various complex alcohol acid phthalates, sperm oil, and purified lanolin. In the operation of the device illustrated in Fig. 1, the rust-inhibiting liquid is applied to the freshly cut edges of the blanks between the cutting and forming operations as follows. The liquid is delivered to and absorbed in the felt material 46. The side surfaces of the cutting punch adjacent the cutting end thereof receive a film of the liquid in its movement past the felt material. During the downward and upward movements of the cutting punch 18, a portion of the liquid adhering to the surfaces thereof is transferred to the inner side walls of the cutting die. Should the punch 18 receive an excess deposit of the liquid, the excess will be wiped off by the skeleton sheet as the punch 18 moves downwardly into the cutting die. During the next succeeding stage of the cap-forming operation, the blank cut by the punch 18 is forced ahead of it over the previously coated surfaces of the cutting die 14, whereby the .raw or newly cut edges of the blank receive a film of rust-inhibiting liquid. In order to avoid an overflow of liquid during periods when the sheet stock is not being fed to the machine, the flow of the liquid, as previously described, may be coordinated with the operation of the sheet stock feeding mechanism. Thus, should the feeding of the sheet stock be stopped, the supply of liquid would likewise be discontinued.

Referring to Figs. 2 and 3 of the drawing, a modified form of the invention is shown applied directly to the cutting die of a crown cap cutting and forming machine. The cutting die 14a is provided with an annular groove 52 formed in the inner side wall thereof and spaced a short distance from the upper or cutting edge of the die. The groove 52 is countersunk to provide shoulders 53 against which a porous member 54 is supported. Rust-inhibiting liquid is supplied to the groove 52 and the porous member 54 through a conduit 56. A drainage duct 58 is provided in the cutting die at a point adjacent the forming die 16 to permit any excess liquid to escape.

In operation of the modified form of the invention, the raw or freshly cut edge of the blank is caused to wipe across the porous member 54 as the blank is forced downwardly and inwardly of the cutting die toward the forming surfaces of the die 16 and in this way the cut edge acquires a coating of the rust-inhibiting liquid.

It will be recognized from the foregoing description of my invention for applying rust-inhibiting liquid to the raw edges of newly stamped or punched articles that the coating is applied immediately after the cutting of the article and before there is time for any oxide film to form thereon or dirt can accumulate on the exposed metal to interfere with the protection of the raw edges by the rust-inhibiting liquid. As is brought out above, my invention utilizes the usual cap-forming apparatus and the steps of operation thereof in applying the rust-inhibiting liquid without slow6o ing down the speod of production or adding any appreciable expense to the manufacturing process.

While I have shown and described two forms of my invention, I am fully aware that many modifications and variations thereof are possible; and for this reason, it i to be understood that the forms of the invention herein illustrated and described are intended to be illustrative of the invention and nit to limit the scope of the appended claims.

I claim: 1. In apparatus for manufacturing stamped or punched articles from metal in strip or sheet form, the combination with a cutting punch and die of means for protecting the raw edges of the newly cut articles from corrosion including means for effecting a surface presentation of a rustinhibiting liquid adjacent the cutting edge of the die in a position to insure wiping engagement therewith of the raw edges of newly cut articles as they move away from the cutting edge of the die thereby completely coating said raw edges with said liquid.

2. In apparatus for manufacturing stamped or punched articles from metal in strip or sheet form, the combination with a cutting punch, a cutting die having wall portions adjacent and posteriorly of the cutting edge of the die provided with a porous structure, and means for supplying rust-inhibiting liquid to said porous structure, said porous structure being so positioned in the walls of said die as to wipe the raw edges of newly cut articles and coat them with said liquid as they pass from the cutting edge of said die.

3. In apparatus for manufacturing stamped or punched articles from metal in strip or sheet form, the combination with a straight sided cutting punch and a cutting die of means for rust-proofing the raw edges of the newly cut articles including means defining a chamber surrounding the cutting punch and through which the punch is adapted to reciprocate, liquid applying material contained in said chamber in contact with the side surfaces of the punch, the inner walls of the die being continuous and of substantially the same shape as the cutting edge thereof, and means for supplying rust-inhibiting liquid to said material, whereby a substantial amount of the liquid applied to the straight side surfaces of said punch is transferred to the walls of the cutting die adjacent the cutting edges thereof for application to the raw edges of the next successively ciut article.

4. In apparatus for the manufacture of crown caps or similar closures from metal in strip or sheet form, the combination with a die having a tubular portion adjacent the cutting edge thereof, of means for providing a supply of rustinhibiting liquid, means for sweating said liquid onto the inner surface of said tubular portion and means for causing the raw edges of the newly cut blanks to wipe said inner surface and thereby receive a coating of rust-inhibiting liquid.

5. In apparatus for the manufacture of crown caps or similar closures from metal in strip or sheet form, the combination with an assembly head, a cutting punch and a cutting die, of means for rust-proofing the raw edges of newly cut blanks including an annular member having an inwardly extended flange adapted to fit closely about the side surfaces of the cutting punch, means for securing said member to said assembly head to form an annular chamber between said flange and the assembly head adjacent the side surfaces of said punch through which said punch is adapted to reciprocate, the inner walls of the die being continuous and of substantially the same diameter as the cutting edge thereof, and means for supplying rust-inhibiting fluid to said chamber for application to the side surfaces of said punch for transfer to the walls of the cutting die, whereby the raw edges of the blank cut by the next succeeding stroke is adapted to receive a coating of rust-inhibiting liquid.

6. In apparatus for manufacturing stamped or punched articles from metal stock in sheet or strip form, in combination with a cutting punch and a cutting die, means associated with said punch and said die for applying a coating of rust-inhibiting liquid to the raw edges of the newly cut articles immediately after they are severed from the strip or sheet by coaction of the cutting punch and the cutting die.

ARNETT E. BENTON.