US2836917A - Etching machine - Google Patents

Description

June 3, 1958 N. c. SCHUTT ETAL 2,836,917

ETCHING MACHINE 4 Sheets-Sheet 2 Filed Aug. 3, 1955 lNVENTORS ATTORNEYS June 1958 N. c. SCHUTT EI'AL 2,836,917

ETCHING MACHINE Filed Aug. 3, 1955 4 SheetsSheet 3 Norman C. Schufl, John Louis Bielland,

Flnyd W. Flynn ATTORNEYS Fig. 3.

United States Patent ETCHING MACHINE Norman C. Schutt, Gien Cove, John L. Bjeiiand, Huntington, and Floyd W. Flynn, Glen Cove, N. Y., assignors to Powers Chemco, End, Glen Cove, N. Y., a corporation of New York Application August 3, 1955, Serial No. 526,284

8 Claims. (Cl. 41-9) This invention relates to etching machines for etching printing plates and the like and has specific reference to a machine wherein etching acid is continuously sprayed against the plate during the etching process and where an irregular motion is imparted to the plate during this process to insure that the etching will be uniform throughout the entire area of the plate.

Objects and advantages of the invention will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

In the drawings:

Figure 1 is a plan view of the etching machine of the present invention with portions of the machine being broken away and with the mechanism for imparting an irregular motion to the printing plate shown mounted on top of the machine.

Figure 2 is a front elevational view of this mechanism for imparting an irregular motion to the printing plate and is taken generally from line Z2 of Figure 1.

Figure 3 is a rear view or" the carriage which forms a part of this mechanism with this view being taken from line 33 of Figure l and showing in detail the sector gear drive for imparting a reciprocating motion to the carriage.

Figure 4 is an end view of the mechanism for imparting an irregular motion to the printing plate and is taken generally from line 4-4 of Figure 2.

Figure 5 is a sectional view of this mechanism taken along line 5-5 of Figure 2.

In etching machines of the type to which the present invention pertains, etching acid is contained in a housing or tank and is continuously sprayed by suitable mechanism against a printing plate introduced and retained in the housing for the time necessary to etch the plate as desired. In order to have uniform acid distribution and accordingly uniform etching of the printing plate it has been recognized that it is highly desirable to continuously move the plate through a constantly varied motion pattern during the etching process with the motion that is imparted to the plate preferably being both reciprocatory and rotary and restricted to a plane generally normal to the direction or" spray projection. While there are several known etching machines which provide an irregular motion pattern for the plate being etched during the etching process, such as the machines disclosed in United States Patent Numbers 2,669,048 and 2,700,838 issued to I. A. Easley et al. and W. E Guenst, respectively, each of these known machines have certain inherent undesirable characteristics in that an irregular motion pattern of the plate is not insured or operational difiiculties are experienced because of the particular design and construction of the drive mechanism with stoppages, breakdowns, and/ or repairs being relatively frequent.

The present invention has for its object the provision of an improved etching machine of the type wherein during the etching process acid is continuously sprayed against the plate while the latter is moved in an irregular motion pattern. Another object of the invention is to provide such an etching machine wherein the drive for imparting this irregular motion to the plate includes a rack and pinion with the rack being in the form of a worm that is continuously rotated during the etching process and with the pinion being in the form of a worm wheel intermeshed with the worm. Another object of the invention is to provide such an etching machine having this drive and wherein the plate to be etched is supported from a carriage that is continuously reciprocated through a predetermined amplitude with the worm wheel being mounted on and carried by the carriage and with the worm being mounted on the machine free of the carriage. Another object of the invention is to provide such an etching machine wherein the worm and the carriage are driven through a common drive mechanism. Another object of the invention is to provide such an etching machine wherein this mechanism for imparting an irregular motion to the plate is mounted for simultaneous movement to and from a position where the plate is operatively disposed within the machine and a position where the plate is located exteriorly of the machine, with this movement being permitted only when the plate is within a limited range of rotative positions and with an indicator being provided to indicate the rotative position of the plate. A further object of the invention is the provision of such an etching machine that is rugged and highly reliable in its operation and which results in uniform etci ing of the plate. 7

In accordance with the present invention the etching machine comprises a housing or tank upon the top or side of which is mounted mechanism effective to impart an irregular motion to a printing plate that is supported within the housing and has acid sprayed against its face by any suitable means. The plate is removably secured to a support member disposed on the end of a shaft that extends outwardly through a slot provided in the top or wall of the housing and which is carried by a carriage in a manner permitting rotation of the shaft about its axis. The carriage is mounted on the etching machine in a manner so that it may be reciprocated longitudinally of this slot with the carriage and accordingly the shaft connected thereto being continuously reciprocated at a uniform linear velocity through a motor driven drive including a sector or mangler gear rotated by a motor through a speed reducer and positioned between a pair of toothed racks provided on the carriage for alternate engagement with these racks. The shaft is rotatably driven in response to reciprocation of the carriage by a drive assembly that includes a pair of intermeshed gears one of which is secured to the shaft while the other is secured to a drive shaft that is journaled to the carriage in parallel spaced relation with the shaft that carries the plate to be etched. Also secured to this drive shaft is a pinion which is continuously intermeshed with a rack which is mounted upon the machine free of the carriage and extends in parallel relation with the axis of reciprocation of the carriage. This pinion is in'the form of a worm wheel while the rack is in the form of a worm andis mounted upon the etching machine in a manner so that it may rotate about its axis but is prevented from moving in a longitudinal or axial direction. During reciprocation of the carriage the worm is continuously rotated and for this purpose suitable drive mechanism is provided with this drive mechanism being driven by the same motor that drives Mounted upon housing; supports printing plate .14 within the housing and imparts c r a V the sector or mangler gear through which the carriage is continuously reciprocated and with the rotation imparted to the worm being such, as tofc'ontinuously vary the rota-. V tive positionof theplaterelativefto its linear positionwith V successive .recipro'cations'pf the. carriagefand"accordinglyimparting an irregular motion pattern tothe plate. "This mechanism for imparting this 'irregulan'mo'tion 101 the plate ism'ounted upon .a portion of. the machine which ciprocal movement. 'Reciprocal movement of the. carprovides for pivotal movement of this mechanism to and .1

from an operative position where the plate is opera'tiveifv disposed within the machine and a position where the plate is located exteriorly of the machine and may readily be attached or removed from this mechanism.

The"

opening provided in the cover'or wall of the machine and I through which the plate 'must pass during this pivotal inovementiis generally of such size that the, plate must be in aparticular position in order to be able to pass through this opening.

in its operative position withinthe machine with the indi- .cato-r being visible exteriorly of the machine and being .actua'ted through the shaft upon which the plate' is sup ported.

n will 'be understoodthat the foregoing general description-and the following detailed description as well are For this, reason an. indicator v isprtn/idcd' for indicating the rotative'position of the plate when his 4 ria e is limited by spaced stops 69 secured to rod 22 p being so positioned that gear '48 will 'propwith these erly mesh the teeth of racksSt) and SZupon becoming disengaged from one and engaged with the other of these racks. W

Carriedby and iournaled to body memberifau of 'cartriage 21 are the spaced parallel shafts6 and 62 each of I which extends through this body portion with shaft '62 being mounted within spaced bearings 64 secured within V bore 66 and with shaft 61) being mounted within spa ced bearings 68 secured withinbore 749.. Artial'movement of each of these shafts is prevented by collars 72 which are 4 I secured to the'shaft's at a location immediateiyoutwardly of each of the bearing members. Frame member and p 1 housing 1!? are provided with an elongated slot 74 para lle l' exemplary and explanatory of the invention but are'nct V restrictive thereof. 7 7 a Referringnow to the drawings'wherein likereferen'ce characters are used throughout to designatelike elements,

7 the illustrative and preferred embodiment o'fthefinven tion' disclosed therein comprises a housing-or tank It), only a fragmentary portion of which is shown, andwhich is adaptdto contain a suitable etching fluid as well as.

suitable means for continuouslyspraying the fluid against the face of. a printing plate; that is to be etch ed all as is well known in thea rt'. V

an irregulanmotiion' to the plate during the etchingjopera- 7 tion. .While this mechanism is shown as mounted on the top 'or cover, of the housing it may equally. well be mounted upon a vertical or 'slantedwall of the housing; so long as the acid sprayimpinges againstthefac'e of'plate "14. The mechanism. '12 comprises a frame member 20 overlying and secured'to the top of housing Mounted.

is the mechanism 12Which with the axis of reciprocation of the carriage and through which extendssha'ft 6t) with flange 76'being'securedto the innene'nd of this shaft. The printing plate 14"is-supported within housing 16 during the etching process by support plate '78 which issecured to the inner surface of flange 76 by screws 89 with special clamp means 81 being provided to permit easy attachment and removal of the printing plate to. and from the support plate and with these clamps being adjustable to accommodate plates of difier- -ent sizes. Leakage of acid spray from the interior of housing It along shaft 66 is prevented by bafiie plate pr ring member 82 which is positioned immediately below 7 housing 84 secured to the underside of the top wall of tank It) and within which housing is' disposedgfloatring ring 85 with this'baflie 'plate, housing and ring-forming a labyrinth which effectively prevents the escape of acid;

V spray from within the tank or housing 1 0.

Rotation of shaft 6%) is effected in, response itoreeipro- '5 J cation of the carriage throughthe drive 'assenibly desig natcd on the. drawings. generally as 84 and which inimmediately above and in spaced relation. to this frame memberis thecarriage 2l which is received or supported upon the parallel, laterally spaced support rods 22'arid 24 for reciprocal movement therealong with these rods being secured to and extending between spaced support brackets V 26 and 28 which extend upwardly from frame member 2%.

The'carria-ge- 21 cornprises the generally horizontallydisposed body member 30 to one end of which issecured,

which embrace r0d.24 therebetween. Extending inwardport rod 22 is snugly but slidably received; 7

Reciprocation of carriage 21 along the spaced parallel rods 22 and 24is effected through a suitable motor driven drive mechanism which includes motor 42 and speed reducer 44'both of which are mounted upon support frame which is driven at a uniform speed by motor 42 through speed reducer 44. This sector gear 48 is interposed be ment in an axial direction. by cap screws 32, the upright' plate' member 34 and on the other end'of which is mounted spacedrollers 38 2 1y from the inner face of plate 34 are the spaced ears-40 which are provided with coaxial bores withinwhich sup- Rack member 36 extends between and is-journale eludes rack member 86 in continuous engagement with which is pinion 88 mounted upon and secured ,toihe;

upper end of shaft 62. Also secured to'shaft 62 is' gear $0 which is intermeshed' with gear-92 disposed iupon;and

secured to shaft 60 so that the rotationof-shaft62 is imparted to shaft 60through thesegears9012 1 2....

spaced support brackets 26 and 28 so that fthe' raek' is'f free to rotate about its axis but is prevented from rnovea u As carriage 21" is] reciprocated in opposite directions along rods 22'and 2 4'shaft; 60 is rotated in opposite directions through this rack I and pinion drive with pinion fifi being continuously in-j termeshed with rack .86 and caused to'r'otatef by axial movement of the carriage. a s 1 As embodied, rackand pinion 86 'and88 are in the form of a worm and worm wheel, respectively, and in order to provide an irregular motion pattern for plate 14 this worm 36 is continuously rotated during reciprocal V movement of the carriage at such a'speed that the rota-, i

7, able drive mechanism which, like sector gear48, is driven V tween the'spaced toothed racks 50 and 52, which are se- J by motor 42 through Spfid Ieducer 44 Wlth' thls drive cured to th e inner surface" of spaced fianges 54 and 56,

' respectively, that extend laterally from platemember 3 with these racks being retainedin positionby' screws 58 'that' extend-through the respective flanges; These racks are in parallel relation'with support rods 22 and 24 and arealternately engaged by the toothed portionof the sec:

mechanism including shaft 94'which extendslthrough and is journaled within housing 9 6.whichformsla partuof 7 support bracket28i Secured"to. one end of, 'thej shaft 7' 'is'pu1ley98which" is interconnected with and driyen frohl pulley 1001by belt 1021withit his later pulley'beingk mounted uponshaft 46. the other endof shaft is secured worm 104 which is continuously intermeshed with worm wheel'106 securedto the end of rack or Worm 86. Thus, as carriage 21 is reciprocated through motor 42, speed reducer 44, and sector gear 48, worm 86 is continuously rotated at a relatively slow speed so that an irregular motion pattern for plate 14 is established.

In order to facilitate attachment and removal of plate 14 to and from support plate 78 the mechanism 12 is preferably mounted upon a portion of housing which is hinged so that this mechanism may be pivoted from its operative position depicted in the drawings to a position where the plate is located exteriorly of the housing and accordingly is readily accessible. In the illustrative organization the portion 108 of the cover of the machine may be pivoted in this manner through the medium of hinges 119 with the plate 14 passing out through opening 109 provided in the top of the machine as this portion 1118 is pivoted upwardly and with gasket 111 providing a fluid tight seal when this portion 108 is in its lowermost position and plate 14 is operatively disposed within the machine. Alternatively, rather than hinging only a portion of the cover of the machine the entire cover may be pivota-lly mounted if desired.

With certain sizes of printing plates that are utilized it is necessary that the plate be in a particular rotative position or in other words have a particular orientation with respect to the housingor tank 10 before mechanism 12 may be'pivoted either to or from its operative position, where the plate is located within housing 10, since otherwise the plate would contact the wall of the housing and prohibit this pivotal movement. Inasmuch as it is impossible to determine the exact rotative position or orientation of plate 14 after the etching operation is complete without gaining access to the interior of housing 10, a suitable indicator is provided whichis visible exteriorly of the machine and provides a continuous indication of the rotative position of the plate with this indicator comprising dial 112 formed on the end of support member 114 which is provided with later-ally extending bosses 116 and is supported from body member of carriage 21 by means of spaced arms 118 which are secured to these respective members by cap screws 120. Extending through and journaled within the bore provided in support member 114 is shaft 122 to one end of which is secured beveled gear 124 that is intermeshed with an identical gear 126 secured to the upper end of shaft 60. On the other end of shaft 122 is secured pointer 128 which overlies the face of dial 112 with suitable indic-ia 13%) being provided on this dial so that when pointer 128 is positioned therebetween the rotative position of plate 14 within housing 10 is such as to permit pivotal movement of mechanism 12 about hinges 110 to a position Where the plate is located exteriorly of housing 10 thereby permitting the plate to be readily removed and another readily attached to the support plate 78.

In operating the present invention a printing plate that is to be etched is attached to support plate 78 by means of the clamps 81 and the cover or the portion of the cover 108 together with mechanism 12 is then moved to its operative position where plate 14 is dis posed within housing 10. During the etching process this printing plate is continuously reciprocated through a predetermined amplitude through the toothed arc of sector gear 48 and the spaced toothed racks 5t and 52, with this drive mechanism being effective to move the carriage 21 and the plate at a constant linear velocity throughout the extent of their movement in each direction and with acid being continuously sprayed or splashed against the inner surface or the plate during this reciprocal movement.

In response to reciprocation of the carriage through its opposite directions of movement shaft 60 and accordingly plate 1d are rotated in opposite directions through 5 the rack and pinion drive 86 and 88. Rack or worm 36 is continuously rotated during reciprocal movement of the carriage with the rotation of this worm being at a relatively slow speed such as to provide an irregular motion pattern for the plate with the respective linear and rotative positions of the plate varying with each reciprocal movement.

Thus, with the present invention not only is the motion pattern of the plate irregular during the etching process, but the linear and rotative velocities imparted to the plate are uniform and do not vary widely, as was the case heretofore, resulting in more uniform distribution of the acid over the total area of the plate and accordingly more uniform etching.

The invention in its broader aspects is not limited to the specific mechanism shown and described but departures may be made therefrom, within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. In an etching machine of the type wherein acid is continuously sprayed against a plate to be etched, the combination of a carriage mounted for reciprocation through a fixed amplitude, means for reciprocating said carriage including a pair of parallel spaced toothed racks mounted on the carriage, a motor driven sector gear between the racks alternately engaging one or the other of said pair of racks, a rotatable plate support mounted on said carriage, a pinion driving said support, a rack mounted parallel to the path of carriage reciprocation and in driving engagement with said pinion, means driven from said motor for continuously progressing said rack during reciprocation of the carriage, support and pinion whereby relative rotational position of said support with respect to its linear position varies with each reciprocation of the carriage.

2. In an etching machine of the type wherein acid is continuously sprayed against the plate to be etched, the combination of a carriage mounted on said machine for reciprocation through a fixed amplitude, means for continuously reciprocating said carriage, a support rotatably mounted on said carriage for movement therewith to support a plate to be etched, means for rotating said support in response to reciprocation of said carriage including a worm and a worm wheel continuously intermeshed therewith, said worm wheel being rotatably carried by said carriage and effectively interconnected with said support, said worm being rotatably mounted on the machine in generally parallel relation with the axis of reciprocation of the carriage and held against axial movement thereof relative to the machine, said worm being continuously rotated about its axis during reciprocation of carriage.

3. The etching machine of claim 2 wherein the means for reciprocating the carriage through a fixed amplitude comprises a pair of spaced toothed racks mounted on said carriage in parallel relation with the axis of reciprocation of the carriage and a motor driven sector gear stationarily mounted on said machine for rotation about its axis and interposed between said racks for alternate engagement therewith.

4. In combination with an etching machine of the type described, a carriage mounted thereon for reciprocating movement, means for continuously reciprocating said carriage through a fixed amplitude, a shaft carried by and journaled to said carriage, said shaft extending into said machine and carrying on its inner end a support for a plate to be etched, a rack in the form of an elongated worm mounted on said machine in parallel relation with the axis of reciprocation of said carriage and in a manner permitting rotation about its axis but preventing axial movement thereof relative to said machine, said worm being continuously rotated during reciprocation of the carriage a Worm wheel intermeshed with said Worm and carried by said carriage, said worm wheelbeing rotatable about its axis and being eifectiv'e to rotate said shaft.

I 5. The etching ma chine of claim 4 wherein rotation of the Worm and reciprocating carriage are driven by a common'motor.

rocation of said carriage and held against axial -move- V ment relative to said machine;.said worm and worm wheel being continuously intermeshed, and means for. con- 7 tinuously "rotating said Worm during reciprocation ofthe 6. The organization of 'claim wherein the drive for rotating'the worm during reciprocation of the carriage includes a reduction gear train with a driven gear secured to oneendrof said worm and having a driving gear intermeshed therewith. V

7. Anetching machine of the type wherein during the etching process acid is continuously sprayed against the face of the plate'to be etched While an irregular motion is'imparted to said plate comprising in combination, a container within which the acid is contained and the plate disposed during the etching process, mechanism mounted innerend a support for aplateto be etched, a drive shaft. carried by and journaled tosaid-carriage in spaced relationto said shaft'carrying said support and being inter connected therewith through a gear train, aworm wheel mounted on and secured to said drive shaft, a rack in the form of an elongated rotatable worm mounted on said machine in 'parallel relation with the axis of recip- Tcarriage and including La worm wheel secured ,to 'said V shaft and intermeshed with a worm'journaledto the machine and driven by said motor. I I r 8. In an etching machine of the type wherein acid is continuously. sprayed against a plate to be etched, the combination of a carriage mounted for reciprocation through a fixed amplitude,vmeans. for reciprocating said. carriage including a drive motor, a rotatable plate support.

mounted on said carriage, a pinion driving, said support,

' arotatableraci; mounted parallel to the path of carriage reciprocation and in driving engagement with said pinion and means driven. through reduction gearing from said 7 motor forrcontinuouslyfrotating said rack during recip rocation of the carriage, support and pinion whereby. relative rotational position of said support with respect to its linear. position varies with eachreciprocation of the carriage 1 7 References Citedin thefile of this patent UNITED'STATES PATENTS 27,698 Cooper Apr. .3, .1860 r 45,779, 'Werni a "Ian. 3, 1865 1,390,930 Scott Sept. 13, 1921; 2,669,048 Easley et a1. Feb. 16, 195.4 2,700,838

Guenst Feb; 1, 1955

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