US2995850A - Etching machine - Google Patents

Description

ug- 15, 1961 J. sTRAUss 2,995,850

ETCHING MACHINE ATTORN EY5 Aug. 15, 1961 J. sTRAUss ETCHING MACHINE Original Filed Feb. 6, 1957 FIG.4

F I 6.5 2,44XA

INVENTOR.

ATTORNEYS Patented Aug. l5, 1961 2,995,850 ETCHING MACHINE Joseph Strauss, Hopewell, NJ., assignor to Trenton Times Cprporation, Trenton, NJ., a corporation of Delaware vide an etching machine which is simple and inexpensive in construction, yet which is efHcient and reliable operation.

A still further object of the present invention is to pro- 5 vide an etching machine wherein the etchant uid is dsonlegglcatginaglgagnl 5132: tributed uniformly against the face of a plate disposed-ev 730,209 within the machine. j

s Claims, (C1, 41-9) Other objects and many of the attendant advantages of the invention will become more apparent when con- The present invention relates to a new and novel etchsidered in connection with the accompanying speciiica- Y ing machine, and more particularly lto an etching machine tion and drawings wherein: e utilized in connection with printing plates or the like. FIG. l is a perspective View of the etching machine The present application is a division of U.S. patent with portions thereof being broken away to illustrate the application Serial No. 638,509, led February 6, 1957. principle of operation; y The present invention is especially adapted for use in FIG. 2 is an enlarged sectional view illustrating theV etching magnesium plates as one step in the processing plate rotating means embodied in the etching machine; thereof as, for example, described in the method disclosed FIG. 3 is a -sectional view taken along line 3-3 ofl in my aforementioned copending application. Etching FIG. 2, looking in the direction of the arrows; j y., operations on printing plates are often a critical matter FIG. 4 is a front elevational view of the assemblyv since the `depth of the etches is very important to achieve shown in FIG. 2; A' the desired results. Accordingly, etching operations ordi- FIG. 5 is a transverse sectional view through the etchnarily required Ia very skilled operator in order to achieve ing machine illustrating the cover construction and dethe proper degree of etch. It is a primary concern of the tails of the exhaust ducting system; f present invention to provide an apparatus which may be FIG. 6 is a transverse sectional view taken through one 4 quickly and easily adjusted, and is fully automatic in of the paddle assemblies; t operation whereby the skill required of an operator is FIG. 7 is an elevational view -showing an end portion. reduced to a of one of the paddle assemblies; Y Numerous prior art devices have been constructed for FIG. 8 is an elevational view illustrating the mounting performing etching operations, and one of the problems assembly of one of the paddle shafts; and which has been encountered is the fact that the etching 30 FIG. 9 is a partial perspective view of an end portion I. fluid has a tendency to become concentrated in certain of one of the deecting boards and illustrating adjustablev areas thereof greater than other areas thereby causing an mounting means associated therewith. y uneven etch to be made. It is conventional practice in Referring now more particularly to the drawings' etching machines of this type to raise and lower paddleV wherein like reference characters designate correspond-V 'y assemblies within the machine to control the distribution ing parts throughout the several views, the etching inaor spray of the etching fluid. This, of course, requires a chine is shown most clearly in FIG. 1 and is constructed rather complex and bulky arrangement which is awkward of generally rectangular form and is provided .with v ai' to operate. vertical rear wall 278 and a front wall 279 spaced therel The new and novel structure, according to the present from with side walls 280 interconnecting the front andVl` invention, incorporates a pumping system which is em- 40 rear walls as well as a bottom wall 281- so as toform', f ployed to distribute the etching fluid from a reservoir an enclosure Within which a plate 282 is disposed'during'fsupply to a plurality of troughs from whence the etching the etching process. On the inside of the tank and alongu iluid is distributed to the printing plates by the paddle the bottom thereof is provided an open top trough `283. assemblies The pumping system distributes the etching and a similar trough 284 ,is disposed in spaced paraluid from the reservoir to the troughs, thereby effecting lelism thereto as is shown most clearly in FIG-' l. Each, f a continuous agitation and mixing of the etching iluid to of vthese troughs extends completely in between the sidev prevent concentrations of weak etching iluid. Rather than walls of the machine and associated with each of the'sferl` providing adjustable paddle assemblies -as is common in troughs is a paddle assembly, the ends of'twhich aref;` the prior art, the pumping system is so employed for con- Y shown in FIG. l and designated by the reference char-ll trolling the level of the etching iluid within the troughs acters 285 and 286. Y 'j of the device so that the amount of etchant distributed Each paddle assembly incorporates a plurality fii by `the paddle assemblies is thereby controlled without splashing blades which dip into a supply of etchingl ,solu-` necessitating any movement of the paddle assemblies. tion received in the respective tanks 283 and 284 and, Easily accessible controls are provided on the exterior of when rotated, splash or spray the etching solution for-5 l' the machine whereby an unskilled operator may make a wardly to distribute it more or less evenly against the i few simple adjustments and accurately control the etchface of the plate 282 disposed Within the machin'el- The ing operation. The controls are so connected that an tanks 283 -and 284 are connected directly to the ralY operator may actuate the paddle assemblies either conwall 278 of vthe machine and the paddle assemblies-285 jointly or either paddle assembly may be operated sepa- `and 286 are journalled in the side Walls 280, as will .j rately. more fully described hereinafter. With the'particulr" An object of the present invention is to provide a new arrangement shown, there are actually three supplies of and novel etching machine which may be quickly and etching uid within the interior of the machine."` Thef easily operated and which minimizes the skill required iirst supply, which is actually a reservoir, is contained infn; of an operator. the bottom portion of the machine forwardly of the lowerj" Another object of the present invention is to provide trough assembly 283 `and the level of such supply will, at" an etching machine which substantially eliminates connot time, except the height of the trough' 283 softhat y' centrations of weak etching fluid. there is no communication therebetween. The other'tv'vo l A further object of the present invention is to provide supplies are contained within the troughs 283 and' 284 an etching machine wherein the distribution of etchant and a pumping system is employed to distribute the etch-7^' may be easily controlled, and the paddle assemblies of ing uid from the rst mentioned reservoir supply 'i the machine may be individually operated.

the two troughs 283 and 284 and this forms an impc,l Yet another object of the present invention is to propart of the etching machine assembly inasmuch it ef Y 3 fects-ea `VcontinuousA agitation and mixing of the etching uid so that the tendency for concentrations of spent or weakeching fluid are not apt to occur.

Thepumping "system-embodies one or more pumps such as'ithoseiindicated by the reference characters 287 and A 288, eachhaving a driving means such as the electl'icftllot'ors1 289 and 290. lThe inlet of each pump is so co'nnctedas'to pickvup'the etching uid from the bottom ofil'the-'main'freservoir or supply chamber within the etching`machine, as for example, by means of the inlet pipe" 291"`"sl'iown connected to thepump 288 and being 'p Iinto 'theletching machine through the opening 292 in `tzlrebctto1i1 wall 281. The other lpump 287 is provided wthla, similar inlet pipe 293. The outlet of each pump is 'cqnnectedhrough a valve mechanism suitably accessibleto the operator and discharges' into one or the other or both of Avthe troughs 283 and 284. For example, the 288` is provided with the Voutlet line 294 which preferably ex'tendsup 'along the side wall 280 to a valve 295" an'd"thence connects with a horizontally disposed distribution line296 having'connections 297 and 298 discharging :through theV back wall 278 and into the upperrnost trough 284, whereas the other pump 287 is provided with a similar discharge or outlet line 299 leading to the valve 300 and thence to the distribution line 301having the outlet connections 302 and 303 discharging'into lthellower trough 283.

Inetching machines of the general character herein de` scribed; Iitis conventional practice to raise and lower theI paddle assemblies 285 andA 286 so as to provide a greateror' lesser ldistribution or spray of etching uid upon `the associated plate, the level of etching fluid remaining 1substantially constant within the reservoir supply 'beneath or associated with the paddle assembly. However-,z the present invention contemplates the use of Ipaddle assemblies which, during the normal operation of the'machine, are fixed and wherein the pumping system' associated therewith in the specific embodiment shown inv FIG. Vl and as described above is so controlled asto'ipermit the raising or lowering of the etchant uid within the troughs 283 and 284 so that the amount of etchant :sprayed or distributed by the paddle assemblies is thereby controlled without necessitating any movement of-fthe paddle assemblies themselves.

Furthermore, in the specific embodiment shown, the individual paddles and their troughs with their individual pumping systems permit the individual control of the spr-ay'issuing from each paddle assembly. That is, by utilizing'a 'separate pumping system for each paddle asseibly, thelpaddle assemblies may be individually con-v trolrlled. This' is accomplished by means of the valves 29'5an'd 300which can be manipulated by the operator tohpreset the Yow characteristics in the distribution lines 296V and; v301 so as to maintain'any desired level of etchant within the troughs 283 and 284, thus individually controlling the spray characteristics delivered by the individual'paddle assemblies 285 and :286.

The paddle assemblies themselves are constructed preferably in the manner which is shown most clearly in 'V6 and 7 wherein each Awill be seen to include a pluralityv of individual and separate sections 304, 305, 306,` etc'. Preferably, each of these sections incorporates a centrally disposed hubportion 307 which is hollow so asto receive therethrough a driving axle 308 or 309 as' shown in FIG. 1,'and with a plurality of blade members 310, 311, 312 and 313 projecting radially therefrom and equidistantly spaced' circumferential relationship as Y"sho'v'vn most clearly in FIG. 1. The con-tour of each ofthe/blades is preferably similar to that shown in FIGQG wh'erein there is only a slight concave curvature offtheblades as presented to the etchant during normal rotation ofthe paddle assembly, the rotation -being clock- WiseinFIG. 6. It is'important to note, in connectionv Wift'li,fthecontour?ofY the blades,-that there is no sharp trap the etchant Vas the paddle is rotated, and the curvature is substantially uniform and to such a small degree as to permit the etchant to be thrown from the paddle assemblies in its entirety wihout any amount of the etchant being retained. This assures a uniform distribution ofthe etchant as accomplished by the paddle'assemblies. Y Y

Each of the sections 304, 305, etc. also includesta circularside' plate 314 and when al-lof the sectionsy are mounted upon the associated driving shaft, as is shown in FIG. 7, these side plates314,'=315,316, etc. abut adjacent blade assemblies, as shown, so as to forma unitary paddle assembly and it 'is preferred, in this respect, that the individual blades' be disposed in alignment withV each other along a length of the paddle `assembly as 'is shown in FIG. 7. j

The previously mentioned drive shafts 308 and309 ofthe paddle'assemblies `are journalled at opposite ends in the side walls 280v and at the other end thereof project outwardly from the associated side wall and are provided with means such as the pullies 317 and 318; For the purpose of driving each of the paddle assemblies, there may bemounted on suitable stands or brackets 319 and 320V driving means such as the electric motors 321y andrv 322 operating through belts 323 and 324 to impart the necessary rotation to the paddle assemblies 385 and 286. Referring at this time more particularly to FIG. 8, the

manner of mounting the opposite ends of the paddle drive` shafts will be seen. On the outer side of theassociated side wall 280, there is provided a generally L-shaped bracket member 325 presenting a horizontally disposed outwardly projecting upper shelf portion 326 having a pair of dipped holes receiving therethrough the elevating bolts 327 and 328. The bolts 327 and 328 are connected to a pillow blockA assembly 329 and are rigidly affixed thereto, such pillow block journalling the associated end of the paddle drive shafts, such as the drive shaft 308 as shown. Lock nuts 330 and 331 are associated with the bolts beneath the shelf 326 and when it is desired to make an adjustment of the associated paddleassembly, these lock nuts are backed ol as well as the lock nuts 332 and 333 associated withthe pillow block assembly and the bolts 327 and 328 are turned to raise or lower thev pillow block assembly and, consequently, the associated end of the shaft 308.` When the proper adjustment is attained, the lock nuts are, lof course, re-tightened to hold the assembly rigid. The purpose of they pillow block adjusting means is to permit the paddle `assemblies to be disposed in a direct horizontal position so that they will be uniformly disposed in partial submersions with relation to the etchant solution throughout the lengths of the `same so as to cause a uniformity in the spray action imparted thereby across the entire width of the machine. This is necessary, of course, inasmuch as it is 'easier 'to adjust the positioning of the paddle assemblies than it is to level the entire etching machine with relation to the paddle assemblies which would'otherwise be necessary in order to achieve the proper lrelationship between the etchant level and the paddle assemblies.

Cooperating with each of the paddle assemblies to provide 'the desired spray characteristics is a baffle plate, indicated in FIG. 1 by the reference characters 334 and 3375, one of such bale plates being shown in partial de'- ftail more clearly in FIG. 9. YIn Vthe latter figure, the baille plate 334 will be seen to be provided at its ends with axially projecting journals 336 which project through an arcuated slot 337 in the associated side wall 280 and in lturn journalled within a rectangular'plate member 338 'lying against the outer'sidc of the associated side wall 280. A pair of wing nuts 339 and 340 project through the plate 338 and cooperate therewith and with the arcuate slot 337 to permit the journal end 336 to be located at will at any position within the confines of the slot 337. n

thereof and suitable means, such as a set screw, not shown, or the like, may be utilized to fix the bathe plate 334 in any desired rotated position with relation to the plate 338. By this construction, the angularity of the baille plates as well `as the fore and aft positioning thereof may be adjusted at will to impart the desired characteristics to the spray issuing from the associated paddle asj sembly.

FIG. illustrates Ithe construction of the upper portion of the etching machine and illustrates the cover structure therefore as well as a portion of the exhaust ducting therefor. In this figure, it will be seen that the machine is provided with a partially enclosing top wall 341 which projects forwardly from the back wall 278 and terminates substantially midway between the front and back walls as shown. Preferably, the inner end of the fixed top wall portion 341 is provided with a rigidifying bead 342 of suitable configuration to impart sucient rigidity to this portion of the top to support the overlying slidable cover member 343. The cover member 343 when closed, extends from the inner face of the front Wall 279 to a point beyond the inner edge of the xed top wall portion 341 as shown and is provided thereat preferably with a vertically projecting edge portion 344 serving as a convenient means to grasp the slidable cover and move it backwardly or to the right in FIG. 5 so as to expose the top front portion of the machine to permit the insertion of the magnesium plate and associated support assembly, hereinafter described, into the machine.

For the purpose of exhausting fumes from the interior of the etching machine, the same is provided with one or more exhaust fan structures indicated generally lby the reference character 345 in FIG. 5, which are disposed in vertical alignment below outlet portions 346 of an exhaust ducting system. Associated with the fans 345 may be a shroud plate 347 to direct the exhausted fumes toward the central portion of the fan, the fan being preferably of the centrifugal type.

FIG. l illustrates the manner in which the fans may be driven and, in this respect, the rear wall 278 of the machine is provided with a pair of brackets 348 and 349 which support electric motors 350 and 351 having drive shafts projecting into the machine and mounting the eX- haust fan structure. In this gure also, the exhaust ducting system 352 is more clearly shown.

FIGS. 2 and 3 illustrate the construction of the plate supporting assembly and the manner in which the plate may be manipulated within the machine. In FIG. 2, reference character 353 illustrates a support plate formed of light-weight material, such as aluminum, and having a plurality of uniformly spaced perforations or holes therethrough which are preferably closely spaced so as to render the plate as light as possible. A magnesium printing plate or the like may be lfastened to the support plate by a number of suitable screw fasteners which project through the holes provided in plate 353 to hold the printing plate firmly in place. Support plate 353 is provided with a hub 354 having a bore 370 of substantially square cross-sectional conguration formed therein. Square end 355 of support shaft 356 is disposed within bore 370 and is journalled in a suitable bearing block 357 xed to the inner surface of the front Wall 279. A handle mechanism indicated generally by reference character 358 is fixed to the outer end of shaft 356. Hub 354 is also provided with a notch 371 as seen in FIGS. 2 and 3, the divergent side walls 372 and 373 of which flare outwardly from the bore 370. `The notch, as seen most clearly in FIG. 2, is not as deep as the bore 370 so that when the support shaft 356 is engaged with the hub 354, the outer end portion of the square end 355 of the support shaft will be rrnly sealed within the square socket portion defined by the bore 370 beyond a notch of the hub. The purpose of the notch is to permit the support plate and hub to be easily engaged with the end of Support shaft 356 since the divergent walls 372 and The handle assembly as shown in FIG. 4, is provided l with four radially projecting spokes 359, 360, 361 and 362, the purpose of which Iwill be presently apparent. Fixed to the shaft 356 on the outer side of the front Wall 279 is a stop collar member 363 serving to position the shaft 356 in its innermost position. The purpose of the handle assembly, constructed as shown, is to provide an indexing means for the operator in performing the etching operation. That is to say, each etching operation is done on four sides of the printing plate 282 and the spokes provide =a convenient index for the operator to produce a quarter of a turn `on the support plate assembly 353 and, consequently, the magnesium printing plate 282 attached thereto so as to alternately etch all four sides of the plate 282.

As previously described, the operator may control the spray volume by controlling the valves 295 and 300 and, consequently, the vamount of etchant supplied to the troughs 283 and 284, raising or lowering the level therein to increase or diminish the spray volume, as desired. The operator also has access to a series of control switches along the upper `side of the machine and as are designated by the reference characters 364, 365, 366, 367 and 368. These controls are, respectively, for operating the llian, yfor rotating the lower paddle assembly, for rotating the upper paddle assembly, for operating both paddle assemblies simultaneously, and for energizing the two pumps. In addition to 'these controls, there is a timer mechanism 369 mounted adjacent the controls and preferably including a sweep second hand. By utilizing the controls and operating them in accordance with a prescribed elapsed time, it is possible to eliminate to a large extent, the skill required in the etching operating. In the event that it is desired to etch only certain portions of a plate, the plate should be placed in the machine and only one acid splash paddle assembly is utilized so as to direct the etchant only against those areas of the plate which require etching.

It is apparent from the foregoing that there is provided a new and novel etching machine which minimizes the skill required of an operator to produce proper and uniform results. The apparatus substantially eliminates any tendency for concentrations of weak etching Huid to occur, and the necessity of moving the paddle assemblies to control the amount of etchant sprayed or distributed thereby is eliminated. The paddle Aassemblies of the device may be individually controlled and they Iadditionally provide a substantially uniform distribution of the etchant. The apparatus is simple and inexpensive in construction, and yet is eiiicient and reliable in operation.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, and since the scope of the invention is defined by the appended claims, all changes that fall Within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are therefore intended to be embraced by those claims.

I claim:

l. An etching machine comprising a substantially rectangular tank `for containing a supply of etchant, a pair of troughs mounted within said tank in vertically spaced relationship to each other for containing supplies of etchant separate and distinct -from the supply contained by said tank, a pump system for circulating etchant from said tank to said troughs, a paddle assembly for each of said troughs and each projecting at least partially into its associated trough to contact the etchant therein, means v for driving said paddle assemblies, means for controlling by said pump means to sepa- Y so constructed and arranged that etchant sprayed by each of said paddle assemblies is directed toward saidmounting means such that the etchant will irnpinge upon an article supported by the mounting means.

2. An etching m-achine comprising a tank-like housing providing an etchant reservoir in the lower portion thereof, means for supporting a printing plate in vertical position within said housing, a pair of horizontally disposed, vertically spaced open top troughs fixed within said housing, the lower of -which is disposed such that its top is above the level of etchant in said housing, a paddle assembly associated with each of said troughs, each paddle assembly includinga plurality of closely spaced -blades rotatably supported about a horizontal axis above an associated trough so that theblades pass through the conlines of the tank during a portion of their rotary paths,

' meansV for rotating said paddle assemblies, means for circulating etchant lfrom the housing reservoir to said troughs whereby-to maintain the entire body of etchant in a state of iiow, means for controlling the last mentioned means such that a separately variable predetermined etchant level is selectively maintained in each individual trough which is at least as high as the lowermost portion of the paddle assemblies whereby the volume'of etchant thrown from the troughs is variable, said paddle assemblies and said support means being so constructed and arranged that etchant sprayed by each of said paddle assemblies is directed toward said support means such that the etchant will impinge upon an article supported by the support means.

3. The assembly as defined in and =by claim 2 wherein the printing plate supporting means is manually rotatable to selectively position the plate within the machine.

4. The assembly as detined in and by claim 2 including a deliector plate mounted `within said housing above each of said paddle assemblies, each deflector plate being mounted for varying in angle to the horizontal and for moving the same forwardly and rearwardly in said housing so as to selectively position its leading edge disposed closest to the printing plate.

5. An etching machine comprising a substantially rec:-y tangular tank for containing a supply of etchant, a pairl ofV troughs mounted `'within said tank in vertically spaced relationship to each other for containing supplies of etch-v ant separate and'distinct from the supply contained by said tank, a pump system for circulating etchant from said tank to said troughs, a paddle assembly for each of said troughs and each projecting at least partially into itsassociated trough to contact the etchant therein, means for driving said paddle assemblies, means for controlling the ow of etchant eifected by said pumpV means to sepa# rately` control the etchant level within each individual trough andA thus determine the quantity of etchant splashed therefrom bysaid paddle assemblies, a defiector plate supportedwithin said tank above said paddle assembly for controlling the spray characteristics of the etchant projected from the trough by said paddle assembly, and means for vmounting a printing plate within said tank for action thereon by 'the etchant splashedby said paddle assemblies,V said paddle assemblies' and said mounting means being so constructed land arranged that etchant sprayed by each of said paddle assemblies is directed toward said mountinggmeans such that the etchant will impingeL upon an article supported by the mounting means;

6. An etching machine comprising a substantially rectangular tank for containing la supply of etchant, a pair of troughsmounted within said tank in vertically spaced re.

lationship to each other for containing supplies of etchant separate and distinct from'the supply contained by said tank, a pump system 'for circulating etchantV from said `tank to' said troughs, a paddle assembly'for each of said troughs and each projecting at least partially into its associated trough to contact the etchant therein, means for driving said paddle assemblies, means for controlling the flow of etchant effected by said pump means to sepa# rately control the etchant level within each individual' trough and thus determine the quantity of etchant" splashed therefrom by said paddle assemblies, a deiiectorV plate supported within said tank above said paddle assembly for controlling the spray characteristics of the etchant projected from the trough by said paddle assembly, adjustable mounting means for said deector plate" whereby the angularity of the deiiector plate with respect to the horizontal maybe varied and including means for moving the leadingedge of the deliector plate toward and away from a print-ing plate disposed within the tank, 'and means for mounting a printing plate within said tank for' yaction thereon by the etchant splashed by said paddle assemblies, said paddle assemblies and said mounting means being so constructed and arranged that etchantV sprayed by each' of 'said lpaddle assemblies is directedY toward said mounting means such that the etchant will impingev upon an article supported by the mountingV for supporting a printing plate in Avertical position within said housing, said supporting means being rotatable to selectively position the plate within fthe machine, a pair of troughs mounted within said tank in vertically spaced relationship to each other for containing supplies of etchant separate and distinct from the supply contained in said reservoir, a paddle assembly for each of said troughs and each projecting at least partial-ly into its associated trough tocontact the etchant therein, means for driving said paddle assemblies, pump means for circulating etchant from the supply within said reservoir to each trough so as to vcontinuously replenish the supply of etchant in each trough and maintain the entire body of etchant in agitated, circulating flow, said pump means including a driven pump having its inlet connected to said tank supply and having a first outlet conduit connected with one of said troughs and a second outlet conduit connected with the other of said'troughs, a separate controllable valve connected in each of said conduits for selectively individually controlling the level of etchant in the diierent troughs to thereby eifectively vary the amount of etchant distributed-by` the paddle assembly of veach `in"- dividual trough, said paddle assemblies and said support means being so constructed and `arranged that etchant 2.sprayed by each of said paddle assemblies is directedr Vtoward said support means such that the Vetchant will impinge upon an article supported by the support means.

8. Apparatus as defined in claim 7, including a deector plate supported within said tank above eachof said paddle assemblies for controlling the spray characteristics of the etchant projected from the trough bythe asso*- ciated paddle assembly,.each of said deector plates being separately and individually adjustable whereby the angu- Ilarity of each deflector plate may be separately varied.

References Cited inthe file of this patent` UNITED STATES PATENTS' 1,267,754 Flick May .28, 1918 1,747,168 Holmstrom Feb. 18, 1930 1,825,127 Powers Sept. '29,V 1931 2,669,048 Easley et al Feb. 16, 1954 2,822,635 Mears Feb.`11, 1958 2,827,723 Clarkl Mar. 25, 1958

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