US 2431065 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
c. G. M|LLER 2,431,065 CONTINUOUS WIRE AND STRIP ELECTROPROCESSING MACHINE Filed Dem. 12., 1938 '7 Sheets-Sheet l Riton-wus Nov. 18, 1947. c. G. MILLER 2,431,065
CONTINUOUS WIRE AND STRIP ELECTROPROCESSING MACHINE med Dec. 12.; 193e v sheets-sheet a o o` o a o. o n o d. i 3 a n u u w u ma n n 82.15 u 5:5 .l 325g@ n an NOV. 18, 1947. C, Q MILLER 2,431,065
CONTINUOUS WIRE AND STRIP ELECTROPROCESSING MACHINE Filed Dec. 12., 1938 7 Sheets-Sheet 3 I V N E 5' J A' N u i Jl ma z IS l i f f" s.
TOWER (.GOLING l I a S lnvsnhr l l L Comma-nut Mnuen Nov. 18, 1947. c. G. MILLER 2,431,065
CONTINUOUS WIRE AND STRIP ELECTROPROCESSING MACHINE Filed Dec. 12., 193s '7 sheets-sheet 4 Vn Of Commmml Mmm bg @SQ-M Nov.. l, 1947. c. G. MILLER CONTINUOUS WIRE AND STRIP ELECTROPROCESSING MACHINE Filed Dec. 12, 19558l '7 Sheets-Sheet 5 lnvcnor Commun (1; Mmm b3 M *wlnw' B ktorncga Nov.1s,1947. c. G. MILLER N 2,431.065
CONTINUOUS WIRE STRIP ELECTROPRQCESSING MACHINE Fil'ed nec. 12., '193s 'f sheets-sheet' e 3' Inven Consmm Ne lum :e w M ttornegs Nov. 18, 1%?. c. G. MILLER 2,43L055 CONTINUOUS WIRE AND STRIPA ELECTROPROCESSING MACHINE Filed Dec. l2., 1938 'T Sheets-Sheet 7 srrs orties A"CQNTINUOUS WIRE AND STRIP ELECTRO- PROCESSING MACHINE Constantine G. Miller, Chicago, Ill., assigner to The Meaker Company, Chicago, Ill., a corporation of Illinois Application December l2, 1938, Serial No. 245.169
1 This invention relates generally to an apparatus for electroprocessing of metal, and more particularly to a machine for electrochemically cleaning and electrogalvanizing continuously moving articles and material such as wire. The invention disclosed and claimed in this application is an improvement overmy copending application Serial No. 87,850, filed June 29, 1936.
The apparatus of this invention is especially adapted for electrogalvanizing round or fiat wire, strip steel, metal ribbons, cables, tubing and the like.
It is an object of this invention to provide-an improved electrogalvanlzing machine which will rapidly and completely clean wire or metal strip material and apply a uniform adherent metal coating thereto while the wire is moved through the machine.
1t is another object of this invention to provide an improved electroprocessing apparatus for treating multiple strands of wire or strips wherein electric current is conducted to the strands by means of, contact nger members which are selfadjusting and self-protecting.
Another object of this invention is to provide an improved apparatus of this character which is capable of selectively treating a wire according to its requirement so as to render the same chemically and metallurgically clean prior to electrogalvanizing.
Another object is to provide a multiple wire or metal strand treating apparatus wherein the individual strands or different groups of wires can be continuously moved through the machine at the same or diilerent speeds, as desired.
Another object is to provide an improved electroprocessing apparatus wherein the electrical contact members, which conduct electricity to or' from the strip, are mounted in supporting frames which frames are made adjustable relative to the electrodes. This affords adjustment of the contact fingers so that the wire may be lowered toward the anodes as the anodes wear away, thus keeping the resistance between the anode and cathode more uniform, avoiding unnecessary power losses.
Another object is to provide an electrocleaning and galvanlzing machine through which multiple wires or strands of metal may be continuously guided by individually rotatable grooved sheaves.
sheaves complete through the machine it is possible to move `one or more of the wires through the apparatus at a different speed than others without any dii'llculty.
Another object is to provide an apparatus for electrocleaning and electrogalvanizing of continuous moving articles wherein rinse tanks are substantially eliminated and sprays provided with drainboard means are employed. This conserves space and aords a more economical arrangement without sacrificing the etiiciency oi the rinsing treatment.
Another object Oi this invention is to provide in an apparatus of this nature an improved electrical contact member which will insure electrical contact with the moving wire or strip being ltreated at all times regardless of the smoothness or imperfections of the surfaces of the strip.
'I'hese sheaves are made of stoneware, glass, or the l Another object of this invention is to provide an improved'electrcal Contact member which is self-cleaning and requires the minimum of attention While assuring proper electrical contact with the moving wire.
Another object of this invention is to provide an electrogalvanizing machine having an improved arrangement of the elements wherein the metal strip being treated is subjected to an electrolytic flash cleaner followed by an electrolytic strike anodic treatment prior to electrogalvanizing. This sequence of treatment results in a highly improved, economical and efllciently operating machine.
Another object is to provide a rapid galvanizing machine in which the material to be electrogalvanized is moved continuously and at a high rate of speed through the electrolyte. The electrolyte is kept in motion in the direction reverse to that of the moving wire or strip so as to maintain a uniform distribution of the electrolyte over the surfaces of the wire being electrogalvanized.
In the drawings:
Figures 1, 1A, 1B, l-C and 1-D illustrate the general layout of the electrogalvanizing ma,- chine of this invention. In the drawings the treatment of wires is illustrated but as heretofore mentioned, in place of wire's, metal strips, ribbons and the like may be used.
Figures 1 and 1A are side elevation views illustrating the arrangement oi the pay-oli reels or swifts. annealing furnace. and power washer;
Figures l-B, 1`C and l-D are similar side elevation views showing the general layout of the electrolytic cleaner, pickle, electro-flash, electrostrike, and electrogalvanizing tanks; nBetween the tanks the use or spray rinse and drainboard agences a side elevation view of the Figure 2 is aV general view of the cooling, cir-` culating and filtering system for maintaining the electrogalanizing solution in proper working condition; 1
Figure 31s a detail vertical sectional view taken on the line 3-.3 of Figure 2, looking into the end of the galvanizing tank and showing the arrangement of the electrolyte return conduit n means;
I trolytic strike cleaner taken on theline 8 5 0X Figure 4;
Figure 6 is a detail view partly in section of the ducking sheaves showing the telescoping construction-thereof and bushings provided therefor;
Figures 7 and 8 illustrative double and single grooved sheaves made of stoneware, glass, phenolformaldehyde resin or the like electrical insulating material, certain parts being shown in section to more clearly illustrate the structural shape and mounting on the axle shafts;
Figure 9 is a vertical sectional viewy transverse of the galvanizing tank. with certain parts broken away, showing the adjustable contact ringer frames and electrode adjacent thereto;
Figure 10 is a vertical sectional View taken on the line Ill-I of Figure 9. showing the particular construction of the adjustable contact fingers Figure 11 is a detail view of the adjustable contact finger frame taken on the line I I-I I of Figure 9, looking in the direction of the arrows;
Figure 12 is a detail view of the adjustable frame construction taken on the line I2-I2 of Figure 9 and looking in the direction of the aI'IOWS.
Referring to the drawings in detail, the numeral I3 designates the pay-off reels or swifts employed for feeding the wires I4 as work pieces through the apparatus. These wires are passed over the guide sheaves I and beneath the sheaves I6 while being passed through the lead annealing furnace I1. A I
The wires then pass to the power washer I8.
.The sheaves I9-guide the wires therethrough from whence they pass to the alkaline electrolytic cleaner 20. Th'e wires are guided over the sheaves- 2| and under the ducking sheaves 22, which are made of suitable alkaline resisting material. After passing through the cleaner the wires are moved over other guide sheaves 2I and under the spray rinse 23. Following the spray rinse the wires are drawn throughs. pickle tank 2B comprising sulphuric or other suitable mineral acid.
Ducking sheaves 25 are used for maintaining the wires submerged while passing through the pickling solution. These sheaves are mounted on vertically adjustable shafts as illustrated in Figure 1B and they are preferably made of acid resistant material and are individually rotatable relative to the commonaxle shafts. as shown in Figures 7 andY 8.
When desired the power washer, alkaline cleaner and spray rinse treatment of the wires prior to pickling may be omitted and the wires passed through the annealing furnace, then cooled and g passed directly into the pickling tank.
ing through the tank 3|.
with the surface of the wires being treated.
The wires are made the anode by electric current which is supplied to the wires through the guide sheaves ZI positioned at the end of the tank.
These sheaves preferably are of the telescoping type and are made of metal. Each sheave is independently rotatable on the axle shaft, as shown in Figure 6. The shaft is directly connected with the copper bus bars leading to the electric current supply means.
Vertical adlustable ducking sheaves 29 are centrally positioned in the tank 2l to maintain the wire submerged in the electrolyte while being drawn therethrough. These sheaves preferably are of double grooved stoneware construction, as shown in Figure '1. Where the ceramic material is of sufficient strength single grooved sheaves may be used similar to that illustrated in Figure 8. Passing from the electrolytic flash treatment the wires are moved through the spray rinse 30 over the sheaves 2l and thence into the electrolytic strike tank 3l. This is an anodic cleaning treatment similar to that employed in tank 2l. The construction of the electrolytic strike tank is illustrated in Figures 4 and 5. Electric current flows from the wire to the cathode grid electrodes 32. The electrodes may be made of lead or other suitable material insoluble in the electrolyte. The electrolyte employed in this strike cleaning tank is preferably strong sulphuric acid which is kept cool by the lead coils 33 installed in the tank. Cold water is circulated through these coils. The electrolyte is kept agitated by means of air forced through the perforated pipes 34 positioned below the cooling coils 33, as shown in Figure 5. Electric current is supplied to the wires through the guide sheaves 2l disposed at opposite ends of the tank in a similar manner as provided in the electro-flash treatment. g
The electrode grid members 32 are suitably supported on the member 35 which extends over the walls of the tank as at 36 and are connected with the bus bars 31, which in turn are connected to the negative side of an electric current supply means. A vertical adiustable ducking sheave 38 is positioned centrally of the electro-strike tank 3l under which the wires I4 pass. The shaft 40 upon which the sheaves are rotatably mounted is adjustable vertically in the yoke 4I by means of the screw threaded shaft 42. Vertical movement of the screw threaded member 42 is provided by turning of the handwheel 43. Sheave 38 is made of similar' material to sheave 29 and maintains the wire submerged in the electrolyte while pass- Glass` or other equivalent insulating rod means 39 are suitably positioned between the wires and the cathode grid electrodes 32 to prevent the wires from directly contacting the electrode while passing through the electrolytic strike cleaner.
The wires may be made either the cathode or the anode while passing through the electrolytic flash and strike cleaning tanks, depending upon the individual cleaning requirement of the material being processed. Likewise, one or more electrolytic flash or strike tanks may be used as desired; however. in general, only one electroilash and strike tank will be used. 'I'he tanks will be made of suillclent length to give the proper cleaning of the wires or strip material being electrogalvanized.
The wires, after leaving the electrolytic strike tank 3l, pass over` the sheaves 2| and are subjected to the spray rinse 44 and thence they are conducted through the electrogalvanizing tank 45 under the ducking sheaves 46. In the galvanizing tank 45 the wires are made cathodic and electroplated. Thereafter the wires are conducted tank through the conduit 69 which has a flared discharge outlet similar to the outlet pipe 82. Y
It will be seen that theelectrolyte in the galvanizing tank is kept flowing from one end of the tem illustrated in Figure 2. The suction lines of the pumps are located at one end of the galvanizout of the galvanizing tank over the sheaves 2l at the ends of the tank and subjected to thel spray rinse 41. Thereafter the wires are drawn through a hot rinse solution contained in tank -48 being-submerged therein by means of the ducking sheave 49. From the hot rinse the wires are wound on the take-up reels 50. as shown in Figure 1E. 'I'hese take-up reels may be driven at the same or different speeds so as to move the wires or strands of metal through the electrogalvanizing machine at any desired speed.
Electrolyte cooling, circulating and filtering system The electrogalvanizing electrolyte as used in the galvanizing tank 45 is constantly removed vfrom the galvanizing tank, cooled and otherwise pipe 58. f
Provision ls made for storing a certain amount of the electrolyte in one of the circulating tanks 59. Entrance and exit of electrolyte from the tanks is valve controlled through the pipes 60 and 8| so that the electrolyte may be permitted to flow directly into the circulating tanks and/or storage receptacle Y59 as required. Conduit 6i provides a common exit from the tanks of the electrolyte through the pipe 62 which forms a return inlet means for admitting electrolyte to the electrogalvanizing tank 45. The inlet pipe 62 is positioned at the opposite end of the tank from which the electrolyte is withdrawn and adjacent the side thereof, as illustrated in Figures 2 and 3.
The outlet opening of the pipe 62 is flattened and flared outward, as at 63, so as to distribute the electrolyte over the surface level of the solution. An overflow/pipe 64 communicates with the pipe 82 and the top of one of the intercommunicating circulating tanks 51 to prevent overflowing of the circulating tanks Nshould they become filled for any reason.
Filtering of the electrolyte is provided for by means of the pump 55 and filter press 68. Electrolyte is withdrawn from the galvanizing tank and forced through the illter press by the pump tered electrolyte returns to the other end of the ing tank where the wire enters, while the discharge lines are located 'at the opposite end. In this way the electrolyte in the galvanizing tank is circulated countercurrent to the directional movement of the wires through the electrogalvanizing tank.
The purpose of the several circulating tanks is to insure a thorough remixing and cooling of the electrolyte. It will beappreciated that when cooling of the electrolyte is unnecessary, the cooling tower may be omitted or electrolyte shunted directly into the circulating tanks and returned to the galvanizing tank. as illustrated in Figure 2.
Electrogalvanizing tank The elcctrogalvanizing tank 45 may be \con structed of wood or metal, and whenf of metal is rubber lined, as indicated at' reference numeral 10 in Figure 9. Lead lined metal tanks may also be used.
. In the galvanizing tank construction there is positioned a series of vertically arranged spaced dams 1I. Thesedams may be made of wood, phenol-formaldehyde resin, or any other suitable material which is resistant to the action of the electrolyte employed. The electrolyte is forced to flow over each successive dam which dams are placedadiacent the point of engagement of the electrical contact fingers 12 with the wires and between the opposed ends of the anode electrodes 13. In this way the electrolyte is circulated above the bottom of the tank and is kept in constant movement over the electrodes and the wires.
The anodes 13 extend lengthwise of the tank and parallel lto the wires passing therethrough and rest on the electrical conducting members 14. The latter are in turn supported on the framework 15 resting on the bottom of the tank, as illustrated in' Figures 2 and 9. Electrical conducting members 14 are preferably made of copper bars which are lead coated to prevent being attacked by the electrolyte.
The members 14 extend transverse of the tank and are electrically connected to busbars running along the side of the tank for supplying electric current to the anodes. The current density employed may be upwards of 3000 amperes per square foot. It will be appreciated that the electrical current carrying parts will be insulated from the tank, when made of metal, and be spaced from the oPDQSte electrode.
Referring to Figure 9, it will be observed the electrical contact finger members 12 are mounted on the shaft 16 of the carrier frame generally designated 11. This carrier comprises the contact finger shaft 16 and glass rod 18 which are positioned transverse of the tank and are retained in the flanged end supporting member 19.
The glass rod 18 positions the wires with respect.
to the ngers 12 so that proper contact can be made with the wires by the fingers 12.
The entire unit is vertically adjustable in the l brackets by means of the threaded rod memretained thereto by thenuts 83,threadedcnto^the" w yends of the rods, as shown in Figure 9. By adfastened to the angle irons 84, forming the ledgeV at' the sides of the 'galvanizing tank, by means of the bolts 85. Y
Guide members 86 are positioned onl the angle iron supports 81 by the bolts 08. `Tlie guides are supported below the laterally extending iiange 89 on the member 19. These guides are-provided with a slot 90 for accommodating the vertical movement of the member 19 and integral flange portionii, as shown in Figures 11 and 12. The angle iron supports 8l are suitably anchored to the inner walls of thegalvanizing tank, as shown in Figure 9. The metal parts are rubber covered or otherwise insulated against'contact with the electrolyte. Adjacentrthe ends of the glass rod 'i8 are provided screw locking members 8|.
The purpose of this adjustability of the con;Y
tact finger frame il is to maintain the constant distance of the wire from the surface of the anodes which are positioned below the wire. As the anodes wear away, that is, decrease in thickness, this frame can be lowered so that the wire and contact finger can be correspondingly lowered. In this manner a uniform distance can be maintained at all times between the wires and the anode. `This saves current and keeps the resistance between the anode and cathode more uniform. In this connection it will be appreciated that means may be provided for ad- Justing the positioning of the anode relative to the wire to achieve the same effect. All that is necessary is to have the contact fin-gers, wires and anodes mutually adjustable so that their relative positions may be varied to provide a predetermined distance between the anodes and the wire.
Electrical contact finger construction brass or copper alloy or other suitable electrical conducting material having the required strength and hardness. The finger member is rotatably mounted on the shaft 'i6 which is vertically adiustable in the frame 1l, as shown in Figure 9.
Integral with or attached to the contact finger 12 is an arm 93 slidable on which is a weight 06.
This weight may be positioned on the arm v93 by means of the stud bolt 95 threaded into the weight and contacting the arm S3, as shown in Figure l0.
Positioned around the finger member 02 is a loosely fitted porcelain insulator covering 95. The porcelainA cover is provided with a slot 9i through which is placed a retaining pin 93 which passes through the contact finger, as clearly illustrated in Figure 10. This mounting permits the reciprocation of the porcelain cover relative to the nger. 96 are overhanging ear portions 99 between which the wire or strip being treated passes. An opening |00 in the bottom of the porcelain covering allows the end portion i0! of the contact linger member to protrude and contact the wire or strip i4. The end of the finger portion lili will be grooved or shapedto fit the surface of the'strip` or wire being contacted.-
The upper part of the finger member 82 comprises an enlarged portion |02 which is provided withafsocket for receiving the member |03. The
At the lower end of the porcelain cover manner to the negative side of the electric curl rent generator so as to make the wire the cathode in the electroplating solution. The finger or stem 92 is accurately grooved from the center of the bolt |04 so ythat the weark in the groove on the end of the finger portion |0|` will be uniform.
When the wire kor strip I4 is not passing through the jaws of the insulator, the insulator part 90 drops down and protects the end of the contact finger portion |0| from acquiring a plate. This avoids interference with the function of the-,contact finger yvhen a wire or strip is passing through the electro'galvanizing tank.A When the contact nger is in place, as shown in Figure 10, and riding on the wire, the Wire holds up the porcelain cover 98 and allows the brass or contact finger portion |0| to ride directly on the wire. In this position the tip of the contact finger will become coated with lmetal which is being plated on the wire, but as the splices and imperfections on the wirev pass alon'g, the porcelain cover is moved up and down knocking off the loose, spongy metal maintaining/Aa clean velectrical contact. There is thus provided'anovel self-cleaning and self-protecting electrical/contact finger mechanism. The tensionl onthe wireis gauged by the counterweight 8d which is adjust-ably attached to the arm 93 of the finger` member.
Sheaves Thesheaves usedfor ducking the wires into the various acid, alkali and chemical treating solutions are preferably made of stoneware, glass or equivalent ceramicmaterial which is resistant to attaclr'by the chemical solutions used.
lStoneware sheaves are constructed as illustrated in Figures? and 8 and are of the single or double grooved Wheel type and designated |69 and H0, respectively. Generally the double grooved sheave construction is used in order to provide a sheave of sufficient thickness to have the required strength. If, however, the selected material possesses the required strength, single grooved sheaves, such as illustrated in Figure 8; may be employed.
Around the circumference of the sheaves are formed the `grooves, iii. The sheaves are also provided with a chemical resistant bushing H2 fitted on the axle shaft H3. Tlhe bushings may be made of stainless steel or other chemical resistant metal or non-metal materials.
- Metal ducking sheaves of the telescoping type, such as illustrated in Figure 6, may be used where it is desired to provide electrical connection to The construction of the telescoping sheaves, as
` shown in Figure 6, comprises the individual wheels lill of disk shape having grooves ||5 formed around the periphery. The walls of each sheave which form the grooves comprise a short leg por ing a sleeve of' insulating material having a lgrooved lower end straddling said wire, a rod of Iconducting material loosely extending through the sleeve, said sleeve being secured to said rod at an intermediate position and with -a connection that is adapted to yield in the longitudinal direction to permit movement of the sleeve with respect to the rod in said direction, the lower end o1' said rod being exposed in the groove to 'sheaves are provided with bushings H9 of suitable corrosive resistant material and rotate on the aXle shaft |29.
When wide tanks are used having upwards of forty or more wires in line passing therethrough, the shafts for the sheaves have to be supported in. the center to prevent bending.-
Where a bearing is necessitated, sheave separator members are inserted to separate the twov center wires further apart, to provide space for the bearing installation.
The operation of the electrogalvanizing machine is readily understood from the foregoing description and further explanation is deemed unnecessary.
It will be underdstood, of course, that this invention is not limited to the exact details of construction and operation since obvious modif cations may be made, by those skilled in the art, without departing from the spirit and scope of the description and claims.
Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:
1. In an electrogalvanizing machine for continuously electrogalvanizing multiple metal strands, means for moving said metal strands through said machine comprising guiding sheaves of inert material which are independently rotatable on a common axle, said sheaves having grooves with overlapping leg portions so as to be in telescoping engagement with each other.
2. A guiding wheel member for moving strands of metal lengths in spaced relationshipthrough an electroprocessing machine comprising multiple sheave members which are independently rotatable on a common shaft, said sheaves having grooves with overlapping leg portions so as to be in telescoping engagement with each other to 1provide a compact multiple strand handling un t.
3. In apparatus for the electrochemical processing of a moving wire, including a tank adapted to contain electrolyte, and means for guiding the wire substantially horizontally through said tank below the level of the electrolyte; the combinacontact the wire, the upper end o1' said rod being connected toa source oi' electrical power, and the point of contact with said wire being vertically offset from the pivot point so that a gravitational force yieldingly presses said rod against the wire.
5. In apparatus for the electrolytic mechanical processing of a, moving wire, including a tank adapted to contain electrolyte, and means for guiding the r wire substantially. horizontally through said tank below the level of the electrolyte; the combination therewith of an electric contactor rod pivoted about a point above said wire the end of said rod being in contact with said wire and including a covering o1' insulating material loosely mounted on said rod and having a grooved lower end straddling said wire, the lower end of said rod being exposed in tion therewith of an electrical contactor pivotedk about a point above said wire and including s. .sleeve of insulating material having a grooved lower end straddling said wire, and a rod of conducting material loosely extending through said sleeve, the lower end ,of said rod being exposed in the groove to contact the wire, the upper end of said rod being connected to a source oi' electrical power, and the point or contact with said.
wire being vertically offset from the pivot point so that a gravitational force yieldingly presses said rod against the wire.
4. In apparatus for the electromechanical proc- .essing of a moving wire, including a tank adapting the wire substantially horizontally through said tank below the level of the electrolyte: the `combination therewith of an electric contactor pivoted about a point above said Wire and .1.1191119- Y ed to contain electrolyte, and means for vguidthe groove to contact the wire, the upper end of said rod being connected to a source of electric power, and the point oi' contact with said wire being'vertically oil'set from the pivot point so that agravitational force yieldingly presses said rod against the wire, said covering of insulating material having means connecting the same to said rod, said last-named means including means for allowing some but preventing unlimited sliding movement of said covering on said rod.
REFERENCES CITED The following references are ci' record in the ille of this patent:
UNITED STATES PATENTS Number Name Date 2,094,712 Miller Oct. 5, 1937 2,092,130 Lyons Sept. 7, 1937 2,075,332 Antisell Mar. 30, 1937 2,037,633 Kelvie Apr. 14, 1930 1,991,817 Nachtman Feb. 19, 1935 1,900,534 Wilkins Mar. 7, 1933 1,484,653 Kirschner Feb. 26, 1924 2,080,506 Rinck May 18, 1937 1,803,691 Brockway May 5, 1931 1,322,494 Merritt Nov. 18, 1919 1,191,386 Battle July 18, 1916 954,833 Wallace Apr, 12, 1910 541,986 Sanders July 2, 1895 1,515,092 Cowper-Coles Nov. 11, 1924 2,053,279 Fosburg Sept. 8, 1938 2,146,488 Sykes Feb. 7, 1939 1,115,671 Herrmann Nov. 8, 1914 1,275,887 Finnell A118. 13, 1918 1,917,657 MacChesney July 11, 1933 2,093,238 Damm' sept. 14, 1937 2,203,062 Schueler June 4, 1940 1,425,184 Edison Aug. 8, .1922 1,804,486 Wright May l2, 1931 FOREIGN PATENTS Number Country Da te 63,030 Germany Oct. 9,v 1891 412,582 Great Britain June 25, 1934 19,586 Great Britain 1890 479,869 Great Britain Feb. 14, 1938