US3639056A

US3639056A - Programmed plate-making machine

Info

Publication number: US3639056A
Application number: US47051A
Authority: US
Inventors: Albert Gerson
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-06-17
Filing date: 1970-06-17
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01

Abstract

A photo-offset plate-making machine particularly adapted for the exposure of a series of prints by successively locating a negative carrier in predetermined horizontal and vertical positions relative to a plate-supporting frame for repeated exposure. Illuminated adjustable signal means is provided to indicate the arrival of the negative carrier to said predetermined locations, the signal means being powered by extendable power cords having means for retracting the same depending upon the location of the negative carrier.

Description

United States Patent Gerson 1 Feb. 1, 1972 [54] PROGRAMMED PLATE-MAKING 2,153,186 4/1939 Henderson ..355/70 MACHINE 2,919,635 1/1960 Levine et al. ..355/84 [72] Inventor: glue: Glflrson, Bsaglgwin Road, Yorktown Primary Examiner samue| Matthews mg 10 Assistant Examiner-Richard A. Wintercom [22] Filed: June 17, 1970 Attorney-Charles E. Temko A photo-offset plate-making machine particularly adapted for [52] US. Cl 335555581, 335554785, the exposure f aseries f i t b cce sively locating a l S In Cl negative carrier in predetermined horizontal and vertical posi- 58] Fieid 84 tions relative to a plate-supporting frame for repeated expo- 5 sure. Illuminated adjustable signal means is provided to indicate the arrival of the negative carrier to said predetermined [56] Reierences Cited locations, the signal means being powered by extendable power cords having means for retracting the same depending UNITED STATES PATENTS upon the location of the negative carrier.

3,380,339 4/1968 Moss 3S5/5l 6 Claims, 8 Drawing Figures A? 76 e E T i 3 11 8(0) 36) J n O l I g o I 7'! F A? a U SHEET 1 OF 3 PATENTED FEB 1 I972 PATENTED FEB I i972 SHEET 2 U? 3 PATENTEDFEB H972 3.839.056

SHEET 3 OF 3 ma m3 me A we PROGRAMMED PLATE-MAKING MACHINE This invention relates generally to the plate-making art used in photo-offset lithography printing, and more particularly to a machine adapted for multiplate printing and color work. Reference is made to my prior U.S. Pat. Nos. 3,150,582 granted Sept. 24, 1964; and 3,484,166, granted Dec. 16, 1969; the present invention relating to improvements in structure disclosed therein.

In the photolithographic process, it is frequently desireable to have multiple images in spaced and predetermined positions on the photographic plate, which images are obtained by repeated exposure. Certain economies result from the production of a number of identical reproductions from a single plate impression, and in color work, the number of impressions is equal to the number of colors required. In order to reproduce work of highly acceptable quality, it is necessary that the various color impressions be exactly superimposed. To this end, it is necessary that the negatives used to expose the photolithographic plate be in precise register and proper contact. While devices of this general character are known, because of the extremely accurate machine work required in the fabrication thereof, and the large bulk and weight involved, such devices are relatively costly, and the use thereof is consequently restricted. In addition, the systems employed in prior art machines are complicated and require considerable training before the operator is capable of reproducing satisfactory work.

In my prior above-mentioned U.S. Pat. No. 3,150,582, there is disclosed a device, including a generally vertically oriented frame which supports a negative carrier in such manner that it may be moved in a parallel vertical plane over the face of a support for the lithographic film or plate, and be locked in proper location in any one of a plurality of positions whereby successive exposures may be made. By virtue of cooperating racks arranged along vertical and horizontal axes, it is possible to obtain fine adjustment of the order of one-half of a single rack tooth in either of the two above-mentioned directions before the negative carrier is locked in position just prior to exposure. In my U.S. Pat. No. 3,484,166, there is disclosed a means for obtaining even finer adjustment of the order of several thousands of an inch, which the toothed rack engagement cannot always provide.

While the above-mentioned means are extremely useful, nevertheless, where a plurality of lithographic films or plates are exposed from a single negative, it is still necessary to precisely align the negative carrier using said means each time the negative carrier is moved to a new location. The locating of the negative carrier must be determined by reference to a scale, first with respect to horizontal position, and secondly with respect to vertical position. This has been time-consummg.

It is, therefore, among the principal objects of the present invention to provide an improved indicating means which will visually call attention to the operator of the arrival of the negative carrier, with each successive positioning at the correct location, both horizontally and vertically, without the necessity of resorting to examination of the above-mentioned scale.

Another objection of the invention lies in the provision of illuminated means operative upon arrival at predetermined location of the negative carrier with respect to a plate-support, whereby a series of lithographic films or plates may be exposed from a single negative in rapid succession, and with a minimum of effort on the part of the operator.

Yet another object of the invention lies in the provision of illuminated signal means of the class described, which may be readily incorporated into existing plate-making machines with a minimum of adaptation, irrespective of the means already present in such devices for achieving precise registry.

A further object of the invention lies in the improved signalling means of the class described which may be carried by the negative carrier to be progressively actuated by any of a series of contact closing devices, previously positioned at the start of a given job to constitute a program for exposure, the

programming means being such that it need not be disturbed should it be necessary to use the plate-making machine for single isolated exposures not requiring the program.

These objects, as well. as other incidental ends and advantages, will more fully appear in the progress of the following disclosure, and be pointed out in the appended claims.

In the drawings, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.

FIG. 1 is a front perspective view of an embodiment of the invention.

FIG. 2 is a fragmentary enlarged front elevational view of a chase or negative support incorporating a horizontal axis adjustment means.

FIG. 3 is a fragmentary view in elevation showing a corresponding vertical axis adjustment means.

FIG. 4 is a view in elevation showing self-operative means for storing a power cord used in conjunction with signalling means forming a part of the disclosed embodiment.

FIG. 5 is a side elevational view of an individual circuit closing means forming a part of the embodiment.

FIG. 6 is an end elevational view thereof, as seen from the left-hand portion of FIG. 5.

FIG. 7 is a bottom plan view thereof.

FIG. 8 is a view in elevation of a light element carried by the chase or negative carrier, in such manner as to be selectively engaged by one of a plurality of circuit-closing means shown in FIGS. 5 to 7, inclusive.

In accordance with the invention, the device generally indicated by reference character 9, comprises broadly: a base 10, a lithographic plate support element 11, lithographic plate registering means 12, mounting means 13 for positioning the support element 11, a negative carrier support 14, horizontal registering means 15, vertical registering means 16, means 17 to vertically move the horizontal registering means, and programming means 18. Supported from the base 10 is a negative carrier illumination means (not shown) similar to that disclosed in my prior U.S. Pat. No. 3,484,166, and eliminated from the drawing for purposes of clarity.

The base 10 is possessed of sufficient weight and rigidity to form a stable foundation for the device. Projecting perpendicularly upward from the base are a pair of uprights l9 and 20. Secured between the uprights l9 and 20 are a plurality of struts 21 forming the mounting means 13.

The vertical registering means 16 includes a pair of

racks

23 and 24 which are substantially identical, and in horizontal alignment. Slideably disposed on said racks, are a pair of

housings

25 and 26. Overlying the

racks

23 and 24 are short rack sections 27 which are completely complementary to the racks, so that with relatively light pressure, the rack sections will properly seat or mesh with the racks to immobilize the housings with respect thereto. The rack sections 27 are moved toward and away from the

racks

23 and 24 in a manner disclosed in my prior above-mentioned patent using an operating lever 28.

The

housings

25 and 26 are connected to one point on angular chains 29, which ride on upper sprockets 30 and 31, and lower sprockets 32 and 33. A counterweight (not shown) is mounted on each of the chains 29 to substantially offset the weight of the means 16. The upper sprockets 30 and 31 are fixed on a transverse upper shaft 34 joumaled on the ends of the uprights I9 and 20, respectively. One end of the shaft 45 is connected by a pair of bevel gears (not shown) to be operated by a handwheel 35. Thus, when the lever 28 is in its neutral position, wherein both rack sections 27 are disengaged, rotation of the handwheel moves the shaft 45 and the housings 25 and- 26 up or down to a desired approximate position (as for example to a position within one-eighth inch of the ultimately desired position). Moving the lever 28 up or down will then force one or the other of the rack sections into the racks, and when the parts are fully interengaged, they will be disposed precisely at a predetermined position.

To obtain still closer adjustment, in the order of the nearest one-thousandth of an inch, in the

housings

25 and 26 include auxiliary frame elements 36 arranged for rectilinear movement with respect thereto. The frame elements support a pair of trunnions 37 and turn mounting a stub shaft 38. The shaft mounts a small handwheel or knob 39 at one end, and a threaded collar 40 'at an opposite end which engages a trans verse shaft 41 to transmit motion to a corresponding shaft (not shown) on the oppositely disposed housing. The stub shaft 38 mounts a bevel gear 42 which transmits motion to a bevel gear 43 on a vertically arranged internally threaded bushing 44. This arrangement drives a micrometer gauge 45, the operation of which is more fully set forth in my above-mentioned U.S. Pat1No. 3,484,166.

The horizontal registering means 16 includes a rectangularly shaped member 47 (FIG. 2) supported upon a transverse beam 48 by rollers 49.

Rack sections

50 and 51 selectively coact with a rack 52, and are supported for pivotal movement by pin 53 which provides a pivotal axis in a member 54 which remains fixed with respect to the rack 52 when either rack section is engaged therewith. A pair of corresponding cam rollers, one of which is indicated by reference character 55, are both mounted on a pivotally mounted cam member 55a operated by a shift lever 56. A horizontally adjustable plate 57 is supported in position between upper and

lower guides

58 and 59, respectively, the plate being formed integrally with the member 54, and mounting an eccentric 60 on a shaft 61. The cam includes a manually engageable member 62 for rotation thereof, the eccentric cam surface bearing against the surface of a circular bore in a follower plate integral with the member 47. Thus, with rotation of the cam 60, minute adjustment of the member 47 along the transverse beam 48 is possible. A micrometer gauge 63 is connected to an operating pintle 64, and is fixed with respect to the member 54, so as to indicate movement of the member 47. A lock nut 65 bears upon the shaft 61, and prevents rotation in those applications where minute horizontal adjustment is not required. The nut 65 is providedwith a manually engageable member 66 extending therethrough to facilitate loosening and tightening thereof. The negative carrier support 14 is secured to the lower portion of the. member 47, and thus moves horizontally therewith. From a consideration of FIG. 2, it will be apparent that a simple mode of operations includes the locating of the member 47 by first locking the same using the shift lever 56 and the. subsequent rotation of the cam 60 while reading horizontal displacement on the gauge 63 to the precision desired.

Referring again to FIG. 3 in the drawings, the transverse beam' 48 is provided with a horizontally arranged groove or track 67, in which there is slightably disposed an elongated scale member 68. Preferably, the track 67 is of rectangular cross section including a lower wall 69 provided with a pluralityof small vertically or laterally arranged bores 70, spaced from each other in equal increments, as for example, l-inch intervals. The leftward end of the scale member 68 is provided with a pivotal locking member 71 mounted on a pintle 72, and having a projection 73 selectively engageable in one of the bores 70. Rightwardly of the pintle 72 is an index (a point of zero measurement) 74, and subsequent graduations 75. Extending leftwardly from the member 47 is a corresponding index member 76 alignable with the graduations 75.

While the scale member 68 will normally be positioned with the pintle 72 engaged in the leftwardmost bore 70, in certain types of copy, it may be desirable to arrange the leftward mar gin inwardly from the normal leftward edge of the plate support'element 11. When such is the case, the locking member is manually pivoted out of an engagement with the leftwardmost bore, and the scale member slid rightwardly to the desired location, following which the locking member is again engaged within another bore. With a new reference point established, the member 47 may be moved with relation thereto without the necessity of making a mental addition to each measurement made onthe scale member.

The programming means 18 serves the purpose of simplifying making serial adjustments to the same predetermined position. While the above-described scale may be used for the particular value thereon -is known, which corresponds to the desired position, each time the same position is established, the scale must be viewed in order to establish this position. The means 18 provides an automatically actuated indication upon the arrival of the negative carrier support element at the proper location, both with respect to horizontal and vertical axes of movement. To this end, the means 18 comprises a horizontal axis adjustment element 78 and a vertical axis adjustment element 79.

The element 78 includes a transversely extended bar 81, the axis of which is parallel to that of the rack 52. Mounted upon the bar 81 is a similar rack 82 coextensive with the rack 52,

and having corresponding teeth of identical pitch. A plurality of contact clips, best seen in FIGS. 4, 5, and 6 are selectively engageable with the rack 82 at positions corresponding to desired points along the rack 52. The contact clips 83 are substantially similar, each including a generally C-shaped main body 84, the body including a base member 85, having retaining lugs. 86 at the four corners thereof. Extending upwardly from one end of the base member is a vertical wall 87, in turn supporting an upper wall 88. A manually engageable member 89 is secured to the vertical wall 82 by a rivet 90, the inner end of'which serves as a stop to position the clip 83 with respect to the rack 82. The upper wall 87 mounts a spring91 adapted to engage'an upper surface of the rack, while the base member 85 along the longer edges thereof is modified to provide tooth-engaging projections 92 engageable with teeth on the lower surface of the rack. The retaining lugs 86 maintain an electrically insulated member 93 against the lower surface of the base member 85, the member 93 including a pair of lower tapering surfaces 94 and a horizontal generally centrally located surface 95 defining an elongated groove 96 therein. An electrically conductive member 97 is mounted within the groove 96, and the axis of which is perpendicular to the axis of the rack 82 when the clip 83 is mounted.

The lamp element 98, is mounted by screws 99 upon the member 47, as best seen in FIGS. 1 and 2. The element 98 includes a lamp 100 connected in series with an extensible power cord 101, the circuit running through a pair of contact points 102, the. upper ends 103 of which are of a width corresponding to that of the conductive member 97.

The vertical axis adjustment element 79 is generally similar, including a rack 105 vertical orientation by supporting brackets 106, and having its own contact clips 107 engaged therewith. The lamp element 108 includes a power cord 109 cooperating with an elongated housing 110 which retracts the cord as the negative carrier is lowered.

Referringto FIG. 4 in the drawings, there is illustrated a schematic view of the .elongatedhousing 111 which retracts the power cord 101. The housing is mounted in fixed vertical relation upon the base 10, and includes an open upper end having a pulley 112 tangent to one edge of the opening thereof. Disposed within the hollow interior 113 is a weighted roller.l14 whichengages a medial part of the cord 101. From a consideration of this figure, it will be clear that as the cord is retracted, the'weight of the roller draws a looped segment thereof into the interior of the housing, thereby preventing the cord from becoming tangled with to and fro movement of the negative carrier along a horizontal axis. The cord 109 is retracted within the housing 110 in a similar manner, with the exception that the housing 110 does not require structure corresponding to-the pulley 112.

During operation, the machine is set up for repeated cyclic operation by determining the positions of successive exposures on a single lithographicfilmor plate. This operation will normally require-movement of the negative carrier in a serial fashion to several positions along a horizontal axis. .As these positions are determined, individual contact clips .83 are positioned along the rack 82 in such manner that the circuit through the lamp element 98 is closed, as indicated by illumination of the lamp 100. A similar operation is carried out for the vertical axis adjustment element 79, resulting in the locating of a plurality of corresponding contact clips 107. Once the program has been established, repeated exposures may be interrupted at any time without disturbing this program, as for example, where a single nonrelated exposure is required, following which a return to programmed operation may be made. In making successive exposures, the operator need only initially align the vertical axis adjustment element 79 to its uppermost position, and move the negative carrier rightwardly as seen on FIG. 1, stopping for an exposure each time the lamp 11 is illuminated. When the rightward most clip 83 has been reached, the negative carrier is adjusted so that the next lower contact clip 107 on the vertical axis adjustment element 79 is illuminated, and the cycle along the horizontal axis adjustment element 78 is repeated.

Since the obtaining of any desired degree of fineness of adjustment is already present in the device, an indication of the reaching of this degree of adjustment will depend upon the effective width of the conductive member 97, as measured perpendicular to its own axis, and the contact area on the upper ends 103 of the contact points 102. The contact clips 83 and 107 can be relocated when required for each succeeding programmed operation.

I wish it to be understood that I do not consider the invention limited to the precise details of structure shown and set forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

lclaim:

1. In a photolithographic plate exposing machine, including a lithographic plate support, a negative carrier support movable in a plane substantially spaced and parallel to said plate support, and means for adjusting the position of said carrier support, with respect to said plate support, said last mentioned means including a rack having teeth thereon of predetermined size and pitch, improved means for indicating the adjustment of said negative carrier support to a predetermined location comprising: a second rack connected to said plate support, said rack having teeth corresponding to the teeth on said first mentioned rack, and having a principal axis substantially parallel to that of said first mentioned rack, rack adjusting means for locating said negative carrier support relative to said plate support, said rack adjusting means having teeth corresponding to the teeth on said first mentioned rack, and having a principal axis substantially parallel to that of said first mentioned rack, improved means for indicating the adjustment of said negative carrier support to a predetermined location comprising: a second rack connected to said plate support; at least one electric circuit closing means adjustably engaged with said rack, a lamp element supported by said negative carrier and having a normally open circuit means powering the same, alignment of said lamp element with said circuit closing means serving to illuminate said lamp element.

2. Structure in accordance with claim 1, including an extensible power cord interconnected into said lamp element.

3. Structure in accordance with claim 2, said power cord ineluding an elongated vertically disposed housing fixed relative to said plate support, a weighted member disposed within said housing, said power cord being looped intermediate first and second ends thereof about said weighted member, whereby said power cord may be at least partially stored within said housing with movement of said negative carrier support in a direction toward said housing.

4. Structure in accordance with claim 1, including first indicating means showing a horizontal adjustment of said negative carrier support, and second indicating means showing a vertical adjustment of said negative carrier support.

5. Structure in accordance with claim 1, said circuit closing means including a body member having a pair of parallel rack tooth-engaging portions, and an outwardly facing elongated strip of conductive material disposed substantially parallel to said projections, said lamp element including a housing, a pair of contacts extending outwardly of said housing, said contacts lying in a plane parallel to the principal axis of said strip of conductive material to be simultaneously engaged thereby upon the arrival of said negative carrier support at predetermined location.

6. Structure in accordance with claim 1, including a plurality of circuit closing means positioned at predetermined locations to be selectively illuminated by movement of said negative carrier support.

Claims

3. Structure in accordance with claim 2, said power cord including an elongated vertically disposed housing fixed relative to said plate support, a weighted member disposed within said housing, said power cord being looped intermediate first and second ends thereof about said weighted member, whereby said power cord may be at least partially stored within said housing with movement of said negative carrier support in a direction toward said housing.