US3554892A

US3554892A - Electrolytic machining and fixturing means

Info

Publication number: US3554892A
Application number: US618909A
Authority: US
Inventors: Eugene P Schellens; Roy E Black Jr
Original assignee: Schellens True Corp
Current assignee: TURBO PRODUCTS INTERNATIONAL Inc A CORP OF DE; Dana Inc; Ex-Cell-O Corp; Schellens True Corp
Priority date: 1967-02-27
Filing date: 1967-02-27
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12
Also published as: GB1210697A; SE345975B; FR1595537A; JPS5038623B1

Abstract

A FIXTURING ARANGEMENT UTILIZED IN THE ELECTROLYTIC MACHINING OF SHAPES FROM BAR STOCK HAVING A PAIR OF COOLING CHAMBERS DISPOSED ON OPPOISTE SIDES OF AN ELETROLYTE CONTAINING CHAMBER. EXPANDABLE SEALING MEANS ARE DISPOSED BETWEEN THE COOLING CHAMBERS AND ELECTROLYTE CONTAINING CHAMBER AND SEALIG MEANS ARE ALSO DISPOSED AT THE ENDS OF THE COOLING CHAMBERS REMOTE FROM THE ELECTROYLTE CONTAINING CHAMBER. THE SEALING MEANS ENVELOP THE BAR STOCK PERMITTING IT TO EXTEND THROUGH AND BE MOVABLY INDEXED WITHIN THE COOLING AND ELECTROLYTE CONTAINING CHAMBERS. A GUIDANCE AND ALIGNMENT MEANS HAVING NON-INTERFERING MACHINING ELECTRODE CHARACTERISTIC IS ALSO INCLUDED WITHIN THE ELCETROLYTE CONTAINING CHAMBER TO PROVIDE GUIDANCE AND SUPPORT FOR THE POSITION OF THE BAR STOCK THEREWITHIN.

Description

Jan. 12, 1971 ELP, scHELLENs ETAI- 3,554,392

ELECTROLYTIC MACHINING AAND FIXT-URING MEANS Filed Feb. 27. 1967 4 SheetS-Sheet l SR. mmJ. oLK

P HPC@ mm w W m# m Q @Il rL l Nv vm om /Lmm \.TW www mm ATTORNEYS Jan. 12, 1971 E, P, SCHELLENS ETAL 3,554,892

ELECTROLYTC MACHINING AND FIXTURING MEANS Filed Feb. 27. 1967 4 Sheets-sheet z M fw ATTORNEYS Jari. 12; 1971 E' P, SCHELLENS ETAL 3,554,892

ELECTROLYTIC MACHINING AND FIXTURING MEANS INVENTORS EUGENE P. SCHELLENS ATTORNEYS Jan. 12., 1971 E, p SCHELLENS ETAL 3,554,892

l -ELECTROLYTIC MACHINING AND FIXTURINGYMEANS Filed Feb. 27. 196'? 4 Sheets-Sheet 4 u. K l n ijs? .IV /Y FIG. a

- INVE ORS EUGENE P. SCH LENS.

ROY E. BLACK,JR Fla-9 Mm.

ATTORNEYS United States Patent Office Patented Jan. 12, 1971 U.S. Cl. 204-206 Claims ABSTRACT OF THE DISCLOSURE A fixturing arrangement utilized in the electrolytic machining of shapes from bar stock having a pair of cooling chambers disposed on opposite sides of an electrolyte containing chamber. Expandable sealing means are disposed between the cooling chambers and electrolyte containing chamber and sealing means are also disposed at the ends of the cooling chambers remote from the electrolyte containing chamber. The sealing means envelop the bar stock permitting it to extend through and be movably indexed within the cooling and electrolyte containing chambers. A guidance and alignment means having non-interfering machining electrode characteristics is also included within the electrolyte containing chamber to provide guidance and support for the position of the bar stock therewithin.

Although apparatus utilizing the electrolytic principle for the removal of material and thereby the shaping of intricate, difficult to machine parts is known, none of these prior art devices have provided a high production output and none of these machines have functioned to provide a direct line sequential output. Such an operative arrangement would materially reduce the time required for the production of these parts, such as turbine blades, by reducing handling and feed time of these parts from and to the electrolyte machining operation to thereby reduce the cost of the produced parts to a minimum. It would, therefore, be desirable to provide a direct line production apparatus utilizing the electrolytic removal principle which not only provided a high production rate but also furnished a product whose dimensions and quality could be closely controlled.

Accordingly, it is an object of the invention to provide an apparatus for electrolytically shaping parts including the fixturing therefor, the apparatus having a direct line feed and, therefore, high production.

It is an additional object of the invention to provide the fixturing for an electrolytic apparatus so that product parts may be sequentially formed along the length of bar or strip stock.

It is an additional object of the invention to provide a fixturing for the bar or strip stock that insures proper cooling thereof under the high current rates utilized in the electrolytic shaping of the production items, such as turbine blades and the like.

It is a further object of the invention to provide a positive sealing means which permits sequential movement of the bar or strip stock through the fixturing and also prevents leakage of the electrolyte and coolant outwardly of the fixturing or into an intermingling relationship.

It is an additional object of the invention to provide for positive alignment of the bar or strip stock contacting electrodes to insure intimate contact therebetween and proper conducting of the anode electrical current away from the fixturing.

It is a still further object of the invention to provide an insulating barrier between the fixturing so that the coolant in that portion of the fixturing is at bar or strip stock potential.

Cil

It is still a further object of this invention to provide a variable spacing means in the fixturing to accommodate variable length production turbine blades or the like.

It is a still further object of the invention to positively guide the bar or strip stock within the fixturing which still permits rapid and proper electrolytic machining to occur.

Other and further objects of the invention will be apparent from the following description and claims and may be understood by reference to the accompanying drawings which, by way of illustration, show a preferred embodiment of the invention and what is to be considered to lbe the best mode for applying the above principles.

In the preferred embodiment of the invention a pair of sealed cooling fixtures are disposed on opposite sides of a sealed fixture chamber containing the electrolyte and cathode electrodes, these electrodes being provided with the opposite shape as that desired of the finally finished piece. Each of the sealed cooling fixtures contains a pair of electrodes in contact with the bar or strip stock to serve as a current carrier for it, provisions being made by electrode mounting means to insure that there is intimate contact between the electrodes and workpiece. A sealingfmeans is provided at each end of each of the cooling fixtures to prevent the escape of coolant therefrom and the'intrusion of electrolyte into the cooling fixtures or outwardly to atmosphere from the central fixture electrolyte containing chamber. The bar or strip stock from which the turbine blades or the like are electrolytically machined extends through the cooling fixtures and central fixture chamber with the electrolyte machining apparatus having an indexing means for moving the bar or strip stock the amount required to bring unmachined material into the chamber after a single blade or the like has been formed on a preceding portion of the bar or strip stock. The sealing means, previously described, provides for movement of the bar or strip stock during this indexing operation. Guide means are also provided within the central fixture electrolytic chamber to insure proper alignment of the bar or strip stock so that the cathodes of the electrolytic machining apparatus move uniformly towards the bar or strip stock on opposite sides thereof.

A better understanding of the invention will be had with reference to the appended drawings wherein:

FIG. 1 is a view of the entire device taken generally along line 1 1 of FIG. 2, but shown only partly in crosssection;

FIG. 2 is across-sectional view of a portion of the device shown in FIG. l taken along line 2 2 of FIG. l;

FLIG. 3 is a cross-sectional View of the inner sealing means and related elements as taken generally along line 3 3 of FIG. 4;

FIG. 4 is a cross-sectional view of the inner sealing means and related elements taken on line 4 4 of FIG. 3;

FIG. 5 is an enlarged view of the inner sealing means as shown in FIG. l

FIG. 6 is a cross-sectional view of the sealing means taken generally on line 6 6 of FIG. 3;

FIG. 7 is a cross-sectional view of the guide means taken generally on line 7 7 of FIG. 3;

FIG. 8 is a cross-sectional view of the guide means and locating pad taken on line 8 8 of FIG. 3; and

FIG. 9 is a view in perspective of the lower guide means partly broken away.

The invention comprises an electrolytic removal fixturing 10 that includes, generally, an electrolyte containing fixture chamber 12 located centrally relative to the main body of the electrolytic removal fixturing 10 and a pair of

fixture cooling chambers

14 and 16 disposed on opposite sides of the electrolyte containing chamber 12.

Electrolyte containing fixture chamber 12 is partially formed by a bottom wall 18 and top wall 19 through which a pair of electrodes and 22 of an electrolytic machining apparatus 11 (only partially shown) extend to form the cathode for the electrolytic machining operation, as is seen (FIG. 1). A pair of sidewalls '21 and 23 and a pair of front and back walls 23A, 23A (only the back wall being shown) complete the chamber 12. The front and back walls 23A, 23A may be attached to the other walls of the chamber 12 by any conventional means which insures a seal therebetween. The electrodes 20` and 22 are oppositely disposed so as to machine both sides of the portion of a bar stock 24 that extends through the electrolytic containing fixture chamber 12 and

fixture cooling chambers

14 and 16. Each of the electrodes 20 and 22 is mounted on a feed means 26 that advance or retract the electrodes linearly in a unitary but opposed manner as electrolytic machining of the bar stock 24 occurs. A housin-g 28 supports each of the feed means 26 by attachment of the Ihousings 28 by a series of bolts 29 to the walls 18 and `19, respectively, of the chamber 12. A pair of sealing means 33 and 35 are disposed between the -feed means 26, the bottom wall 18 or top wall 19 and the housing 28 to prevent escape of the electrolyte from bottom or top area of the electrolyte containing chamber 12. As is conventional in the art, each of the feed means 26 is preferably controlled by a means (not shown) to advance the electrodes 20 and 22 so that machining of the bar stock 24 occurs in a predetermined and desired manner. An inlet and an outlet means 45 and 47 (FIG. 7) provides, as is conventional, a continuous flow of high pressure electrolyte solution upwardly between the electrodes 20 and 22, this flow of electrolyte also cooling the portion of bar stock 24 within the electrolyte containing chamber 12.

Each of the fixture cooling chambers 14 and 16 (FIGS. 1 and 2) is a generally closed container of elongated rectangular configuration with a bottom wall 30, top wall 31,

side walls

33, 35 and front and

back Walls

37 and 39, forming, along with an insulating Wall 164, the confines for the volume of the closed container. Disposed within each of the

fixture cooling chambers

14 and 16 are a pair of clamping electrodes 32 and 34 that are pivoted on pins 36 and 38 extending from the side '

walls

33 and 35 and fixedly supported thereby by outwardly extending

fixed pintles

41, 41 and 43, 43 to provide a secure pivotal connection for the electrodes 32 and 34. The clamping electrodes 32 and 34 are each provided with a portion 40 that extends rightwardly of the pivot pins 36 and 38 (FIG. 2) and which portion 40 is pivoted to a clamping block 42 by a pin connection 44 extending loosely through the portion and threaded into the clamping block 42. An aperture 46 of rectangular shape provided in the clamping block 42 permits the portion 40 to extend therein so that clamping block 42, itself, serves as a trunnion for the portion 40 and connected pivot pin 44. A bore 48 is also provided in the clamping block 42 to provide means for assembly of the pin 44 to the clamping block.

The clamping blocks 42, upon movement of the clamping

portions

40, 40 towards each other, abut opposite sides of the bar stock 24 and, because of their free floating relationship within the

chamber

14 or 16, provide an intimate electrical contact therewith to positively lead the electrical current imposed on the bar stock 24 by the electrolytic machining operation away from it. The electrical current is then led from each clamping block 42 to a pair of cables 50 and 52 that are attached to each of the clamping blocks 42 by a pair of

set screws

54, 54 threadedly mounted in a pair of bores 56, 56 provided in the clamping block 42. The cables 50 and 52 seat in a pair of bores 58, 58 provided in the clamping 'block 42 when engaged by the set screws so that both a good physical and electrical connection are provided between the cables 50 and 52 and the clamping block 42.

The

fixture cooling chambers

14 and 16, at the location of each of the cables 50 and 52, are sealed from atmos phere by a sleeve 53 which is attached to its respective cable by moulding the sleeve around the cable, for example, so as to provide an air and water tight connection therebetween. Each sleeve 53 is located on its cable so that it extends through the top or

bottom wall

31 or 30, a seal being provided between it and the top or

bottom wall

31 or 31 by a pair of O-rings 55, 55 which permit the sleeve 53 and attached cable to slide without leakage as the clamping electrodes 32 and 34 pivot on pivot pins 36 and 38.

Actuation of the clamping electrodes 32 and 34 is accomplished by a double acting hydraulic means 60` disposed between the electrodes 32 and 34 at the ends thereof opposite the ends 40. The double acting hydraulic means 60 is attached to the upper clamping electrode 34 by a pin connection `61 or the like and is attached to the lower clamping electrode 32 by a piston 62 of the double acting hydraulic means 60 extending downwardly into a bore 64 formed in a boss 66. The boss 66, in turn, is pivotally attached to the clamping electrode 32 by a pin 63 extending through a clevis portion 67 of the boss 66. It is evident from this arrangement that extension of the piston 62 causes pivoting of the portions 40 of the clamping electrodes 32 and 34 towards each other and moves the clamping blocks 42 into engagement with the bar stock 24 insuring a positive electrical contact therebetween.

In order to permit only limited floating movement of the hydraulic means 60 and the adjacent ends of the clamping electrodes 32 and 34 and to limit downward pivoting of the clamping elctrode 34 due to the force of gravity a pair of

adjustable stops

68 and 70 are provided so as to extend through the

walls

30 and 31, respectively, as by being inserted in threaded

apertures

73 and 75 therein. These stops are adjusted so as to abut against portions of the clamping electrodes 32 and 34 to provide the foregoing action, A pair of

lock nuts

72 and 74 are threadingly received on stops `68 and 70 to insure that these stops may be positively fixed at the desired position of adjustment.

In View of the large amounts of current that must be passed through the bar stock 24 to obtain a rapid electrolytic machining rate, the

fixture cooling chambers

14 and 16 must be supplied with a relatively high flow rate of cooling water. Water flows into each of these chambers through an inlet to be later described, and exits from the chamber through outlet pipes 76 and 78 (shown in phantom in FIG. 2) Which communicate with the interor of the chamber through the front wall 37. It is, of course, important to keep the water flowing through the cooling

chambers

14 and 16 relatively pure, especially that water flowing through the fixture cooling chamber 14 since this portion of the flow serves as a bath -for the machined bar stock 24 and, therefore, flushes the small amount of electrolyte remaining on the bar stock from the electrolytic machining operation. This flushing prevents further uncontrolled electrolytic machining from occurring in the fixture cooling chamber 14.

A sealing means 80 (FIGS. 1 and 5) is provided on the outward side of each of the

fixture cooling chambers

14 and 16 to positively prevent the escape of cooling water therefrom and yet to permit indexing of the bar stock 24. The sealing means 80 includes a generally oval shaped seal member 82 with flattened faces on the long sides thereof (in cross-section shown in FIG. 6) made of neoprene or the like and having a rectangular aperture 83 which extends through a main body portion 81 thereof for entrance of the bar stock 24. The seal member 82 thus surrounds the periphery of the bar stock 24 contained therein to provide a seal between it and atmosphere and with the remainder of the sealing means 80 prevents leakage of cooling water from the cooling

chambers

14 or 16. A pair of axially spaced first flanges 84, 84 of fairly small axial thickness relative to their height extend radially outwardly from the main body 8l of the seal member 82 and substantially around one-half of the pcriphery of the seal member 82. A pair of axially spaced second tianges 86, 86 projecting from the main body 81 are joined to the first fianges 84 and extend around the remainder of the periphery of the seal member 82. The second flanges 86 are of thicker axial dimension than the first flanges 84 so that they, in conjunction with the first anges, form a peripheral groove 88 that extends completely around the seal member 82, said groove having two different adjoining widths.

A metallic ring member 90, preferably made of stainless steel to resist corrosion, is seated in and extends entirely around the peripheral groove 88. Ring member 90 is of substantially the same width as the grooves 88 and thereby varies in width over its length so as to abut against the flanges 84, 84 and the anges 86, 86 within the groove 88 to form a cavity 89 of varying axial dimension between the ring member 90 and seal member 82. As will be later explained, the ring member 90 limits outward expansion of the seal member 82 upon pressurization and directs its expanding force into sealing engagement with the bar stock 24.

The seal member 82 is disposed within a circular bore 92 forming a cavity in an extension 94 of the fixture cooling chamber and abuts inwardly at its inner face 85 against an inner seal retainer 96, this retainer being mounted within the bore 92 and, in turn, abutting an inner terminatingface 93 thereof. Inner seal retainer 96 is of larger diameter than seal member 82 and of cylindrical shape so as to extend Aradially outwardly of the seal member 82 and is provided with an O-ring 98 between its outer periphery and a circumferential wall 99 that forms the bore 92 to thereby provide a seal therebetween and prevent leakage of cooling water radially outwardly of the Seal member 82. A rectangular aperture 100 with a tapered enlarged portion 101 providing easy entrance of the bar stock 24 extends through the inner seal retainer 96 to permit linear movement of the bar stock 24 through it. Seal retainer 96 is preferably made of plastic, such as nylon or the like, so as to serve as an insulator for the bar stock 24.

Surrounding and extending radially outwardly of the seal member 82 and also disposed within the bore 92 is a. cylindrically shaped seal housing member 102. This member abuts against inner seal retainer 96 by means of a shoulder 104 formed thereon and prevents outward movement of the inner seal retainer 96 and also prevents outward movement of the O-ring 98 by abutment therewith by an extension 105 projecting inwardly from the main portion of the seal housing member 102 A bolt 106 extends axially through the main portion of the seal housing member 102 and the inner seal retainer 96 to compressingly connect the seal housing member 102 to the extension 94, a depression 107 being provided in the seal housing member 102 for the purpose of seating the head of bolt 106. A seal is also formed between the seal housing member 102 and the circumferential wall 99 forming the bore 92 by an O-ring 108 which is disposed in abutting relation with both of them and seated in an annular groove 109 in the seal housing member 102 to provide another outer area of sealing for the sealing means 80.

A bore 110 of generally attened oval shape in crosssection, extending axially and medially in the seal housing member 102, receives the seal member 82 in a centralized position, radially, to center it so that the rectangular aperture 83 of the seal member 82 is aligned with the rectangular aperture 100 in the inner seal retainer 96. The bore 110 also seats a plastic seal bushing 112 of flattened oval shape in cross-section made of nylon or the like to insulate the seal housing member 102 of the sealing means 80 from the bar stock 24 and center it so that a rectangular aperture 114 extending therethrough is aligned with the previously related bar stock receiving apertures 83 and 100.

Seal bushing 112 is tightly sealed from seal housing member 102 by an oval shaped sealing ring 116 disposed substantially medially its axial extent in a generally annular groove 117 provided therein so that another sealing area is maintained outwardly of the seal member 82. The length of the seal bushing 112 is sufiicient to protrude outwardly beyond the axial extent of the seal housing member 102 so as to be urged inwardly into engagement with the seal member 82 by a cap member 118 of disk shape, the said sealing member 82 being axially compressed by this arrangement. The cap member 118 tightly holds seal bushing 112 against the seal 82 by impingement against an outer face 87 thereof within the bore 110, the cap member 118 being held by a plurality of bolts 113 fastening the cap member 118 to the outer end of extension 94. The bolts 113 also fasten the extension 94 to its respective

fixture cooling chamber

14 or 16.

Means are provided to supply fiuidic pressure to the seal 82 so that it, because of the compressive force applied by the ring member 90, the inner seal retainer 96 and the seal bushing 112, expands inwardly into intimate contact with the bar stock 24 in order that no cooling water can escape from the

fixture cooling chambers

14 or 16. More specifically, this means includes a transverse bore 122 having threads therein that extends inwardly slightly over half-way through the wall 99 forming the bore 92, the transverse bore 122 thereby providing connection for a fitting for a conduit hose 119 or the like (partially shown) extending to a uidic pressure supply (not shown) such as a pressurized source of air, oil or water. Communication inwardly with the bore 122 is made by an unthreaded counterbore 111 which extends through the remainder of the wall 99 and communicates by way of a passage 121 in seal housing member 102 having the shape of an inverted L with an aperture 123 formed in the thickened portion of the ring member 90, this aperture extending completely through the ring member to provide an air passage to the cavity 89 which, as set out previously, is the space formed between the ring 90 and the main body 81 of the seal element 82. Thus, liuidic pressure may be imposed on the seal 92 and, because of the compressive force of ring member 90 and seal bushing 112, when liuidic pressure is imposed thereon, the main body 81 of the seal member 82 expands inwardly to tightly grasp bar stock 24 and provide an extremely effective seal therebetween. Outward leakage of cooling water from the

fixture cooling chambers

14 and 16 from areas other than that adjacent the sealing member 82 surrounding bar stock 24 is, of course, prevented by O-rings 98, 108 and 116.

The sealing means 80, just described, provides a water tight seal between the atmosphere and the

fixture cooling chambers

14 and 16 and also permits extension movement of the bar stock 24 when indexing is required. At this time liuidic pressure is removed from the seal 82 and its frictional grip on the bar stock 24 is removed. But, substantially no or very minimal leakage occurs at this time even though cooling water and electrolyte solution are still fiowing in the

fixture chambers

12, 14 and 16 because an effective seal is still imposed between seal member 82 and bar stock 24 due to the compressive force of the ring member 90 and seal bushing 112.

Since various lengths of turbine blades or the like may be required to be electrolytically machined from the bar stock 24, the extension 94 containing the sealing means 80 is provided in a variety of lengths. The proper length of extension 94, dependent upon the length of finished blade, is then selected for attachment to the leftwardmost end of the fixture cooling chamber 14 to insure that the sealing means 80 envelops and engages the periphery of the bar stock 24 between machined blades in an unmachined portion 25 thereof.

A pair of inner sealing means 124 (FIGS. l, 3, 4 and 6) are also provided between the electrolyte containing chamber 12 and the

fixture cooling chambers

14 and 16 to prevent the mixture of water and electrolyte solution either in the electrolyte containing chamber 12 or in the iixture cooling chamber 14'and 16, respectively. Each of the sealing means 124 includes a seal member 82 and a ring member 90, exactly the same as previously described, disposed between the electrolyte containing chamber 12 and the

fixture cooling chambers

14 and 16.

Each of the seal members 82 is prevented from inward movement towards the machining electrodes and 22 disposed within chamber 12 by abutment against an insulating locating pad 126 of substantially flattened oval shape in cross-section made of nylon or the like which, in turn, is prevented from inward movement by engagement with a flattened oval shaped shoulder 127 formed in a guide means 128 for the `bar stock 24, the guide means 128 being provided in the electrolyte containing chamber 12. An epoxy adhesive 130 disposed between a shoulder 129 of the guide means 128 and the locating pad 126 fixes the locating pad 126 to the guide means 128 and also aids in sealing the electrolyte containing chamber 12. A seal retainer 132, also made of nylon or the like and having an outer periphery of generally flattened oval shape, abuts against the outer side of seal 82 to prevent its outward movement. This seal retainer is seated in a -fiattened oval shaped bore 134 in the guide means 128 and is sealed therefrom by a pair of iiattened oval shaped sealing rings 136, 136 so that there is no flow of the contained electrolyte solution between the guide means 128 and seal retainer 132 radially outwardly of the seal 82. As illustrated, the seal retainer 132 is of sufiicient length to extend axially outwardly of the bore 134 beyond the guide means 128 to abut by a shoulder 133 on the seal retainer 132 (FIG. 4) a seal retaining clamp 138. The seal retaining clamp 138 extends around and envelops the seal retainer 132 around a circumferential periphery 137 formed thereon and limits the seal retainer 132 against outward movement by a series of -bolts 139 attaching it to the guide means 128.

Mounted outwardly of the seal retainer 132 and seal retaining clamp 138 is a wedge seal member 140 made of insulating plastic which abuts with one of its faces the outer face of the seal retainer 132 and also abuts, on its opposite angled sloping face 142, an oppositely disposed angled sloping face 144 formed on the insulating wall 164 (shown only fragmentarily in FIG. 3), this sloping face being provided in a cutout 145 (FIG. 1) in the insulating wall 164. The wedge seal member 140 is urged downwardly to move the seal member 82 into compressed position against the locating pad 126 by a set screw 146. The set screw 146 is screwingly engaged in a top plate 148 made of insulating plastic material so as to abut against a face 141 formed by the termination of a bore 143 in the wedge seal member 140 and urge it in the compressing direction for the seal member 82.

Top plate 148 is mounted to the guide means 128 by being abutted against a shoulder 150 formed in the guide means 128 near its end and seats thereon on a flat face 151A formed in the guide means 128. Top plate 148 is fixed to the guide means 128 by a series of bolts (not shown). By the arrangement just described, the sealing means 124 including the seal member 82 and the ring member 90 completely seals the electrolyte containing chamber 12 from the

fixture cooling chambers

14 and 16, respectively, in the area surrounding the bar stock 24 and also provides for movement of the bar stock 24 as indexing occurs by release of fiuidic pressure upon the seal member 82 in the manner set forth previously in the description of sealing means 80, a pair of -

bores

121 and 125 and an aperture 123 in the guide means 124 and ring member 90, respectively, providing for entrance of the fiuid under pressure. The

bores

121 and 125 may take the form of the bores for entrance of liuidic pressure described previously for the sealing means 82. Such bores may include enlarged threaded portions for attachment of ttings for ease in conduit connection.

The guide means 128 includes an upper supporting member 149 and a lower supporting member 151 which, when viewed in assembled relation in cross-section near their ends (FIG. 6), provide the guide means with a rectangular configuration that generally encompasses the inner sealing means 124. A pair of thickened

end portions

153, 153 and a pair of thickened

end portions

155, 155 are provided on the upper and lower supporting

members

149 and 151, respectively. These thickened end portions properly space the guide means 128 within the electrolyte containing fixture chamber 12 by seating the guide means 128 in

apertures

157 and 159 in the chamber walls 21 and 23 (FIG. 1). The

end portions

153 and 155 are securely held together by 4bolts 147 (only two shown) extending completely through the upper end portion 153 and screwingly seating in the lower end portion 155. The

end portions

153 and 155 terminate inwardly slightly beyond the locating pads 126 so that ow of electrolyte adjacent the electrodes 20 and 22 is unimpeded by their mass.

Disposed between the

end portions

155 and 155 on the lower supporting member 151 (FIG. 9) are a series of

stringer members

161, 163 and 167. The

stringer members

161 and 163 are generally rectangular in crosssection and provide support and rigidity to the guide means 128. In furtherance of this aim, these members may be integral with or welded to the

end portions

155, 155. The stringerY member 167 is also fxedly attached to the

end lportions

155, 155 and is generally rectangular in cross-section at its upper portion but has a tapered bottom portion 171 so that electrolyte solution streaming upwardly through an inlet means 45 provided between the

stringer members

161, 167 and 163, 167 is not severely impeded in its flow and the turbulance thereof controlled. Stringer member 167 also mounts on its upper side a guide channel 176 (FIG. 7) serving as a lower guide and alignment means for the bar stock 24 as it traverses the electrolyte containing fixture chamber 12.

Disposed axially intermediate the widths of the thickened

end portions

153 and 153 of the upper supporting member 149 and extending between the end portions is a single stringer member 178 which may be made integral with or welded to the

end portions

153 and 153 to provide structural rigidity to the upper supporting member 149. Stringer member 178, as stringer member 167, also supports a guide channel 176, this guide channel serving as an upper guide and alignment means for the bar stock 24 as it traverses the electrolyte containing fixture chamber 12. Because of the absence of structure on opposite sides of the stringer member 178 an outlet means 47 is formed on ropposite sides of the stringer member to provide for outward flow of the electrolyte solution and thereby removal of this solution from the area adjacent the electrodes 20 and 22.

The

guide channels

176 and 176 are made of an insulating plastic and are generally U-shaped in end view and cross-section to provide for proper tracking of the bar stock 24 as it traverses therealong. These guide channels extend linearly along the full length of the

stringer members

167 and 178 and also extend outwardly beyond the stringer members so as to enter and be seated in the locating pads 126, 126 (FIG. 8). A pair of upper and

lower apertures

182 and 184 are formed in each of the locating

pads

126, 126 for this purpose. Thus, the

guide channels

176, 176 are constrained from movement transverse to the linear extent of the remainder of the guide means 128 by the locating pads 126, linear movement of the

guide channels

176, 176 in the direction of the bar stock 24 being prevented by abutment of the ends of the

guide channels

176, 176 with the

seal members

82, 82 of the inner sealing means.

lt should be apparent that the guiding means 128 just described provides a positive support and alignment meansand an insulating means for the bar stock 24 in its movement through the electrolyte containing fixture chamber l2 while still affording an nnimpeded area between tlie stringer members of the upper and lower supporting members 149 and 151 (the area between

stringer members

161 and 178 and the area between

stringer members

163 and 178, respectively) for the movement of the electrodes 20 and 22 inwardly towards the bar stock 24. Convenient inlet and outlet means comprising the before mentioned inlet 45 and outlet 47 are also formed by the spacing of these stringer members to permit the flow of electrolyte to be directly impinged n the work area of the bar stock 24 adjacent the electrodes and 22.

Since the bar stock 24 in the area of the inner sealing means 124, 124 is conducting a high fiow rate of electrical current, entrance of the cooling water flow through

fixture chambers

14 and 16 is adjacent each of the sealing means 124, 124 to prevent burning of the bar under the sealing means where no cooling can be done. Cooling water flows to the area adjacent the sealing means 124 through a pipe or conduit (not shown) which is conveniently attached to a conveniently internally threaded flange 156 fixed by epoxy or the like to the top plate 148. Flange 156 communicates with a bore 158 extending through the top plate 148, the said bore being angled outwardly and upwardly to provide sufficient peripheral area on the top plate 148 for attachment of the flange 156. Communicating with the bore 158 in the top plate 148 is a bore 160 extending through the upper wall 149 of the guide means 128, the said bore 160 being placed in confluent relationship with the bore 158. This bore, in turn, communicates with an annular groove 162 in the seal retainer 132 with the groove 162 extending 360 around the seal retainer 132 to serve as a distributing passageway for the inward ow of cooling water.

A plurality of channels 164 in the seal retainer 132 communicate -with the annular groove 162 and extend angularly inwardly therefrom to provide a flow of cooling water which impinges against bar stock 24 immediately adjacent the inner sealing means 124 and then flows outwardly around the bar stock 24 (FIG. 1) into its respective

fixture cooling chamber

14 or 16. Outward liow therefrom, as set out previously, is through

outlet pipes

76 and 78.

The cooling water fiowing adjacent to the inner sealing means 124, 124 is not at the potential of the electrolyte containing chamber 12 but is kept at the fixture cooling

chamber potential

14 or 16 because of the isolation afforded by the various members of the sealing means 124 having insulating properties. Also, additional insulation in the form of the insulating walls 164 are disposed against opposite sides of the fixture electrolyte containing chamber 12 and between it and the

fixture cooling chambers

14 and 16 to insure that the

fixture cooling chambers

14 and 16 remain at their own potential.

Each of the insulating walls 164 (FIG. 1) is fixed by an epoxy resin 165 or the like to the wall 35 of its respective fixture cooling chamber and covers substantially the entire surface confronting the electrolyte containing chamber 12, the ends of the insulating wall 164 nesting against shoulders formed on the confronting chambers. By the insulating arrangement of the inner sealing means 124 and glass wall 164 no errant electrical current flows between the electrolyte containing chamber 12 and the

fixture cooling chambers

14 and 16 and all current flowing outwardly from the electrolyte containing chamber 12 is constrained to flow within the bar stock 24.

Means is provided for indexing the bar stock, this means being shown generally schematically at 166 and being conventional in character so as to provide movement of the bar stock 24 a desired amount upon actuation to provide an unmachined portion within the electrolyte containing chamber 12, the index modulus selected also locating an unmachined portion of bar stock 24 within the inner sealing means 124 and 124. This unmachined portion, of course, is also of sufficient length for forming the desired size of turbine blade or the like.

The

fixture cooling chambers

14 and 16 are completed by an access port 168, generally conventional in character, mounted on the wall 30 over an opening 171 therein. The access port 168 includes a viewing station 169, rectangular in shape, and made of translucent material and held in water hight relation to the wall 30 by a rectangular flange 170 mounted, in turn, to the wall 30 by a plurality of -bolts 172.

A single embodiment of this invention has been shown and described and it is readily apparent that many changes may be made therein without departing from the scope of this invention vas defined in the following claims.

What is claimed is:

1. A fixturing for the electrolytic machining of elongated stock material comprising in combination; (a) an electrolytic chamber for containing an electrolytic solution under pressure, (b) said chamber having a plurality of walls with at least one of said walls having a first opening therein for receiving the elongated stock material with a first portion of the material disposed in said chamber and a second portion of thematerial projecting beyond said one wall, (c) a cathode electrode disposed in said chamber for electrolytically machining the first portion of the elongated stock material and including means mounting said electrode for movement relative to said chamber and toward the stock material, (d) a cooling chamber for containing a cooling liquid and being disposed adjacent t0 said one wall and connected to said electrolyte chamber, (e) said cooling chamber having an opening therein aligned and conuent with said first opening for receiving the stock material with the second portion of the material disposed in said cooling chamber, (f) anode electrode means disposed in said cooling chamber for conductively contacting the second portion of the elongated stock material, and (g) sealing means carried by at least one of said chambers for sealingly engaging the portion of the stock material intermediate the first and second portions thereof and for sealing the openings in said chambers from each other, (h) said sealing means having an opening therein for receiving the intermediate portion of the stock material and being alternately expansible and retractable in response to a fluidic pressure being imposed thereon and withdrawn therefrom, respectively, for alternately sealingly engaging and disengaging the intermediate portion of the stock material.

2. The combination set out in claim 1 wherein said sealing means includes; (a) a resilient seal member having a deformable outer periphery, said seal member having a deformable inner periphery for circumferentially surrounding the intermediate portion of the elongated stock material and sealingly engaging the same, and (b) means compressingly engaging said seal member adjacent its outer periphery for limiting the outwardly expanding movement thereof.

3. The combination set out in claim 2 wherein said sealing means includes means for compressing said seal member axially. (a) an electrolyte chamber for containing an electrolyte under pressure and for receiving a rst portion of the stock material and having cathode electrode means disposed therein and means for moving said electrode relative to said chamber and toward said stock material, (b) support means disposed within said electrolyte chamber for guiding and aligning the first portion of the elongated stock material, said support means having provision for the entrance of said cathode electrode means for electrolytically machining a portion of the elongated stock material, (c) a first and a second cooling chamber for containing a cooling liquid and for containing second portions of the stock material and being disposed on opposite sides of said electrolyte chamber, said chambers having aligned apertures therein for receiving the stock material, (d) anode electrode means disposed in said cooling chambers for conductively contacting the second portions of the elongated stock material, and (e) sealing means carried by one of said first 1 1 cooling chamber and said electrolyte chamber and carried by one of said second cooling chamber and said electrolyte chamber for sealingly engaging said chamber carrying the same and for sealingly engaging the stock material, said sealing means Ibeing expandible by uidic pressure for providing a positive seal ibetween said chambers.

4. A xturing apparatus for electrolytic machining of elongated stock material comprising in combination; (a) an electrolyte chamber for containing an electrolyte under pressure and for receiving a rst portion of the stock material and having cathode electrode means disposed therein and means for moving said electrode relative to said chamber and toward said stock material, (b) support means disposed within said electrolyte chamber for guiding and aligning the first portion of the elongated stock material, said support means having provision for the entrance of said cathode electrode means for electrolytically machining a portion of the elongated stock material, (c) a lirst and a second cooling chamber for containing a cooling liquid and for containing second portions of the stock material and bein disposed on opposite sides of said electrolyte chamber, said chambers having aligned apertures therein for receiving the stock material, (d) anode electrode means disposed in said cooling chambers for conductively contacting the second portions of the elongated stock material, and (e) sealing means carried by one of said first cooling chamber and said electrolyte chamber and carried by one of said second cooling chamber and said electrolyte chamber for sealingly engaging said chamber carrying the same and for sealingly engaging the stock material, asid sealing means for being expandible by tluidio pressure for providing a positive seal between said chamber.

5. A ixturing apparatus for the electrolytic machining of elongated stock material comprising in combination;

(a) an electrolyte chamber for containing a first portion kof the stock material and an electrolyte under pressure and having cathode electrode means disposed therein and means for moving said electrode means toward the stock material (b) a cooling chamber disposed adjacent said electrolyte chamber for containing a cooling liquid and for containing a second portion of the stock material, (c) electrode means contained in said cooling chamber for conductively contacting the second portion of the Stock material, (d) common wall means forming the adjacent portions of said chambers and having an aperture therein for receiving the stock material, (e) sealing means disposed between said cooling chamber and said electrolyte chamber and disposed in said aperture means for sealingly engaging said wall means and the stock material, and (f) insulating means including at least a portion of said wall means and a portion of said sealing means for insulating said cooling chamber from said electrolyte chamber, said insulating means being interposed between said electrolyte chamber and said cooling chamber whereby the elongated stock material provides the sole electrical path therebetween.

References Cited UNITED STATES PATENTS 2,725,352 1l/1955 Strobel 204-211X 2,756,206 7/1956 Rosenqvist 204-225X 3,296,114 1/1967 Lloyd 204-225X JOHN H. MACK, Primary Examiner D. R. VALENTINE, Assistant Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Parent No. 3 554 ,892 Dated January l2, 1971 Invented@ Eugene P Schellens et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 10 line 58 beginning with (a) an electrolyte chamber" cancel all to and including "between said chambers in line 7 column 11 same column 1l line 32 "asid" should read said Column 12 line 8 after (c) insert anode Signed and sealed this 29th d ay of June 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents FORM IDO-1050 [IO-69) UscoMM-DC 60376-P