Process for treating articles of manufacture to eliminate superfluous projections

Abstract

A sealed system process for the elimination (destruction or removal) of superfluous projections, such as unwanted burrs and sharp edges, on shaped or fabricated articles of manufacture, particularly those produced by mechanical shaping or fabricating, by treatment with transient elevated gaseous temperatures in a sealed and confined space. The transient elevated gaseous temperatures in the sealed and confined space are produced, for instance, by the ignition or other suitable reaction initiation of various compositions which are exothermic in the sealed and confined space, by the rapid and substantially adiabatic compression of a gas in the sealed and confined space or by some other manner such as by the rapid movement of a heated gas wave under pressure through the sealed and confined space, such as exists in a shock wave, so that the transient elevated gaseous temperatures are produced. The transient elevated gaseous temperatures that eliminate the superfluous projections usually have a duration of less than one second and the process is essentially self-limiting and selective in the removal of the superfluous projections. Various means of aiding the elimination of the superfluous projections are also described.

We claim: 
     
       1. The process for the elimination of superfluous thin cross-section .[.surface projections including.]. unwanted burrs .[.and.]..Iadd., flashings, surface irregularities or .Iaddend. sharp edges on an article of manufacture with a much thicker cross-section, the .[.projections.]. .Iadd.superfluities .Iaddend.being produced as the result of shaping or fabricating which forms the article of manufacture, which comprises: (a) providing a sealed and confined space surrounding the .[.superfluous surface projections.]. .Iadd.superfluities .Iaddend.to be eliminated on the article of manufacture such that there are open spaces within the sealed and confined space surrounding the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.to be eliminated; and   (b) generating a transient thermal energy release in a gaseous medium .Iadd.within the sealed and confined open space .Iaddend.thereby producing transient elevated gaseous temperatures in the open spaces within the sealed and confined space.Iadd., .Iaddend.sufficient thermal energy being generated to thermally eliminate the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.without damage to the article of manufacture .Iadd.and without material alteration of the dimensions and configuration of the article of manufacture.Iaddend..   
     
     
       2. The process of claim 1 wherein the confined space is defined by walls capable of withstanding without rupture the transient elevated gaseous temperatures and attendant pressure resulting therefrom and wherein the article of manufacture is introduced into the sealed and confined space so defined. 
     
     
       3. The process of claim 1 wherein the article of manufacture has selected external and internal portions with superfluous projections and wherein the selected external and internal portions of the article of manufacture provide upon closure the confined space which withstands the elevated gaseous temperatures and any attendant pressures resulting therefrom for the elimination of the superfluous projections. 
     
     
       4. The process of claim 1 wherein a gaseous oxidizing material is provided in the confined space which oxidizes superfluous projections simultaneously with the production of the transient elevated gaseous temperatures within the confined space. 
     
     
       5. The process of claim 1 wherein reducing conditions are maintained in the confined space upon production of the transient elevated gaseous temperatures within the confined space such that the oxidation of the article is prevented. 
     
     
       6. The process of claim 1 wherein the transient elevated gaseous temperatures are produced by initiating a reaction in a composition which produces transient elevated gaseous temperatures in the sealed and confined space. 
     
     
       7. The process of claim 6 wherein the transient elevated gaseous temperatures are produced by the ignition of a combustible gaseous mixture of an oxidizer gas and an oxidizable gas in the sealed and confined space. 
     
     
       8. The process of claim 7 wherein the gaseous mixture is hydrogen and oxygen. 
     
     
       9. The process of claim 7 wherein the gaseous mixture is natural gas and oxygen. 
     
     
       10. The process for the elimination of superfluous thin cross-section .[.surface projections including.]. unwanted burrs .[. and.]..Iadd., flashings, surface irregularities or .Iaddend.sharp portions of edges resulting from the mechanical shaping of a relatively much thicker cross-section article of manufacture which comprises: (a) providing the mechanically shaped article of manufacture with .[.superfluous projections.]. .Iadd.superfluities .Iaddend.composed of a material and with a structure such that it resists damage when exposed to transient elevated gaseous temperatures and pressures sufficient to eliminate the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.and any damageable essential parts of the structure being protected from such transient elevated gaseous temperatures and pressures;   (b) introducing the article with the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.into a sealed and confined space defined by walls capable of withstanding the transient elevated gaseous temperatures and pressures sufficient to eliminate the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.so that there are open spaces within the sealed and confined space surrounding the .[.superfluous projections;.]. .Iadd.superfluities;.Iaddend.   (c) generating a transient thermal energy release in a gaseous medium .Iadd.within the sealed and confined open space .Iaddend.thereby producing transient elevated gaseous temperatures and pressures in the sealed and confined space.Iadd., .Iaddend.sufficient thermal energy being generated to thermally eliminate the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.without damage to the article of manufacture .Iadd.and without material alteration of the dimensions and configuration of the article of manufacture.Iaddend.; and   (d) removing the article of manufacture, with the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.eliminated, from the sealed and confined space.   
     
     
       11. The process of claim 10 wherein the transient elevated gaseous temperatures and pressures are produced by the ignition of a combustible gaseous mixture of an oxidizer gas and an oxidizable gas in the sealed and confined space and wherein there is a molar excess of the oxidizable gas over the requirements for reaction with the oxidizer gas to prevent the oxidation of the article of manufacture. .[.12. The process of claim 10 wherein the transient elevated gaseous pressures and temperatures are produced by initiating a reaction in a composition which produces transient elevated gaseous temperatures and pressures in the sealed and confined space and wherein in addition particles of a solid material are provided in the sealed and confined space to facilitate the elimination of the superfluous projections by moving contact with the article of manufacture and the superfluous projections resulting from the reaction 
     
     
        initiation in the composition..]. 13. The process of claim 10 wherein the mechanically shaped article of manufacture with the superfluous projections also has needed surfaces which are protected by masking to 
     
     
        prevent damage by the transient elevated temperatures and pressures. 14. The process of claim 10 wherein the transient elevated gaseous temperatures and pressures are produced by the ignition of a combustible gaseous mixture of an oxidizer gas and an oxidizable gas in the sealed and confined space and wherein there is a molar excess of the oxidizer gas over the requirements for reaction with the oxidizable gas sufficient to 
     
     
        oxidize the superfluous projections on the article of manufacture. 15. The process of claim 14 wherein in addition the surfaces of the article of 
     
     
        manufacture are subsequently cleaned. 16. The process of claim 14 wherein 
     
     
        the oxidizer gas is oxygen. 17. The process of claim 10 wherein the transient elevated gaseous temperatures and pressures are produced by the substantially adiabatic compression of a gas in the sealed and confined 
     
     
        space. 18. The process of claim 17 wherein the gas is an inert gas. 
     
     
        19. The process of claim 17 wherein the gas is an oxidizer gas. 20. The 
     
     
        process of claim 17 wherein the gas is an oxidizable gas. 21. The process 
     
     
        of claim 17 wherein the gas is an oxidizer gas. 22. The process of claim 
     
     
        21 wherein the oxidizer gas is oxygen. 23. A process for removal of superfluous .[.projections including.]. unwanted burrs .[.and.]. .Iadd., flashings, surface irregularities or .Iaddend.sharp edges extending from an article of manufacture and wherein the .[.superfluous projections.]. .Iadd.superfluities .Iaddend.are the consequence of forming, fabricating, shaping or machining, which comprises: extending the .[.superfluous projection.].  .Iadd.superfluities .Iaddend.into a sealed and confined open space and generating a transient thermal energy release in a gaseous medium .Iadd.within the sealed and confined open space .Iaddend.thereby producing transient elevated gaseous temperatures in the open spaces within the sealed and confined space.Iadd., .Iaddend.sufficient thermal energy being generated to thermally eliminate the .[.superfluous projection.].  .Iadd.superfluities .Iaddend.without material alteration of 
     
     
        the dimensions and configuration of the article of manufacture. 24. The process for effecting localized .[.dimensional.]. changes by the removal of .Iadd.superfluous .Iaddend.thin cross-section .[.portions of the surfaces of.]. .Iadd.burrs, flashings, surface irregularities or sharp edges on .Iaddend.an article of manufacture without substantially affecting the established base dimensions .Iadd.and configuration .Iaddend.of the article which comprises: (a) providing the .[.surfaces.]. .Iadd.portions .Iaddend.of the article of manufacture requiring the localized .[.dimensional.]. changes by the removal of the thin cross-section .[.portions thereon.]. superfluities in a sealed and confined space such that there are open spaces surrounding the thin cross-section .[.portions;.]. .Iadd.superfluities; .Iaddend.and   (b) generating a transient thermal energy release in a gaseous medium .Iadd.within the sealed and confined open space .Iaddend.thereby producing transient elevated gaseous temperatures in the open spaces within the sealed and confined space.Iadd., .Iaddend.sufficient thermal energy being generated to thermally effect the localized .[.dimensional.]. changes by the removal of the thin cross-section .[.portions on the surfaces.]. .Iadd.superfluities .Iaddend.within the sealed and confined space without substantially affecting the established base dimensions .Iadd.and configuration .Iaddend.of the article.