Portable etching system for holes drilled in metals

[57] ABSTRACT

A system for controlling the flow of etchant and rinse through metal openings including containers, a manifold, tubing and an adapter for allowing an even regulated flow of liquid through the opening.

Claims, 6 Drawing Figures

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PATENTED JAN?11975

3,861.981

SHEET 1 OF 2

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PATENiTEflM2M975

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SHEET 2 OF 2

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3,861,981

PORTABLE ETCHING SYSTEM FOR HOLES DRILLED IN METALS

BACKGROUND OF THE INVENTION

This invention relates generally to the machining of specialized metals and more specifically to the precision drilling of holes in a metal such as beryllium.

Due to the sensitive nature of some metals to cutting force, each time a particular metal is drilled or machined approximately 0.002 inch of surface metal contains microcracks and is otherwise twinned. After each machining operation, this 0.002 inches of material must be removed. The best known and most common method of removing the material is by acid etching, followed by a rinse with de-ionized water. The best known prior art method of acid etching is by hand, utilizing a common medical Q-tip or similar swab and dipping into the acid and swabbing the hole until the unsuitable material is etched away. It is evident that this method may have been adequate when metals, such as beryllium were considered rare and their use was limited generally to the laboratory. Now, however, the use of these metals is more common and the time consuming methods of the prior art will not fulfill the demands of mass production.

SUMMARY OF THE INVENTION

The invention provides a new and improved means and method of said etching precision machined parts in ₃₀materials and more specifically metals.

With the utilization of a liquid form of etching acid rather than a paste, the invention utilizes a male and female fitting which abut opposite sides of the material and surround the openings to be etched. A liquid form 35 of the etchant is fed through the fittings for a precalculated time. Experience and experimentation allow the operator of the system to stop the flow of etchant at the appropriate time.

The advantage to the invention is in its ability to etch a number of holes simultaneously, thereby allowing a single operator to multiply his work output by as many holes as he is equipped to work with.

It is therefore an object of the invention to provide a new and improved portable etching apparatus,

It is another object of the invention to provide a new and improved automatic portable etching apparatus,

It is a further object of the invention to provide an etching apparatus that is more accurate than similar prior art devices,

It is another object of the invention to provide an etching apparatus with precise control and measure of the amount of material removed.

It is still another object of the invention to provide a system for etching that provides more uniform etching ⁵⁵than any hitherto known,

It is still a further object of the invention to provide a means for etching that is faster than known systems,

It is another object of the invention to provide a sys- ₆θ tern for etching that functions as satisfactory with thick metals as with thin,

It is another object of the invention to provide a system for etching that will allow a multiplicity of holes to be etched simultaneously,

It is another object of the invention to provide a new and improved means of etching that will allow holes and the like to be etched from any position.

It is another object of the invention to provide a new and improved means of etching that may be utilized in compartments or areas accessible only through hand holes.

It is another object of the invention to provide a method of etching that requires little operator skill.

It is another object of the invention to provide a new and improved means for etching that is less hazardous than similar prior art means,

1° It is another object of the invention to provide an apparatus for etching that prevents the escape of dangerous fumes.

These and other advantages, features and objects of the invention will become more apparent from the fol¹⁵ lowing description taken in connection with the illustrative embodiments in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of one embodiment of the invention.

FIG. 2 is a schematic representation of another embodiment of the invention.

FIG. 3 is a side elevation view partly in section of the etchant flow control apparatus.

FIG. 4 is an exploded view of the etchant flow control apparatus.

FIG. 4α is a cross-sectional view taken along line

A—A in FIG. 4.

FIG. Ab is a cross-sectional view taken along line B—B in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, the system utilizes etchant material shown as acid in the container 10 and deionized water for a rinse shown in the container 12. Tubing 14 and 16 connect the containers through the valves 18 and 20 to the manifold 22. The manifold may be con40 structed of teflon or other suitable material and provide any convenient number of outlets. A vent pipe 24 insures an even flow of the fluid acting under the influence of gravity.

A plurality of appropriate tubes 26 connect the mani45 fold to to the work piece 28. A screw-clamp 29 is provided on each tube to adjust and equalize the rate of flow for each hole. A specially constructed adapter 30 allows the fluid to flow through and react with the hole wall of the work piece while containing the fluid within the system. Tubing 32 leads from the adapter to a container 34 that receives the used fluid material.

FIG. 2, illustrates a series flow configuration for the invention. The tubing 40, 42 brings the fluid materials through the valves 44,46 to the manifold 48. A suitable vent is shown at 50. The tubing 52 carries the liquid to the adapter 54 where tubing 56 brings the fluid to adapter 58 where the series continues as necessary until the used material is finally collected in the container.

In FIG. 3 is seen an adapter consisting of a male fitting 62 and a female fitting 64. The tubing 66 engages the male fitting and is held in position by friction force. Female fitting engages the tubing 68 in same manner. In the figure, the fluid, either etchant or rinse, enters the male fitting and flows in the direction of the arrow 70. The fittings are constructed of a strong material that is uneffected by corrosive fluids such as teflon.

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The male fitting 62 has extending therefrom a threaded member 70. This member engages a corresponding threaded portion of the female fitting 64. In practice the male member is positioned through the opening and threaded into the female fitting. A seal between the metal sheet and the male-female fitting is provided by a pair of O-rings 72.

An exploded view of the invention is seen in FIG. 4. The male fitting 74 is shown with an extended member 76. The aforesaid member having a threaded portion 78 with which to engage a mating member 80 on the female fitting.

Fluid entering the male fitting passes through openings 82 as shown more clearly in FIG. 4A. The fluid flows along the sides of the extended member 76, through the metal sheet and into the female fitting 84. The female fitting includes a plurality of openings 86 as shown in FIG. 4B which corresponds to the channels 80 of flow along the sides of the male member. The fluid then flows into the elongated chamber 88 and into the tubing as shown in FIG. 1.

One of the particularly novel features of the invention is that the threaded engagement between the male and female members constitutes an interrupted internal thread whereby the male member screws into the openings of the female fitting and still provides six fluid passages in channels 80.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.