US2596864A - Sheet holding means - Google Patents

Description

E. PENKER 2,596,864

SHEET HOLDING MEANS May 13, 1952 Filed My 2, 1950 5 Sheets-Sheet 1 MN TOR.

ATTORNEY y 13, 1952 E. PENKER 2,596,864

SHEET HOLDING MEANS Filed May 2, 1950 3 Sheets-Sheet 2 IN VEN TOR.

M y 13, 1952 E. PENKER 2,596,864

SHEET HOLDING MEANS Filed May 2, 1950 3 Sheets-Sheet s 3o v A 3! M%ENTOR.

Patented May 13, 1952 y OFFICE SHEET HOLDING MEAN S Ernest Penker, Flushing, N. Y., assignor to Etched Products Corporation, Long Island City, N. Y., a corporation of New York Application May 2, 1950, Serial No. 159,935

6 Claims. 1

This invention relates to printing apparatus and, more particularly, to apparatus for imprinting 'an' electric circuit design on metal foil or the like'as a step in the production of a printed circuit panel.

In the production of printed circuit panels, a sheet of thin metal foil is placed on a suitable backing, such as a plastic panel, and has the de- 1 sired circuit design imprinted thereon with a tacky ink. Acid or etch resist powder is then spread over the printed sheet while the ink is still wet. The powder sticks to the printed portions and is easily removed from the non-printed portions of the sheet. The foil coated panel is then etched, which removes the non-imprinted portions of the foil, leaving. after the ink and resist are removed, only the foil portions defining the conductive path of a circuit design. The circuit may be formed in the same way from a metal foil or metal sheet not mounted on a backing, and later secured to suitable supporting means.

In one form of apparatus, a master design panel is mounted on the flat bed of a machine which also supports a flat fixture having sheets of foil, with or without supporting panels, mounted thereon in set relation to the master design. An ink roller moves from an ink supply over the master and back to the ink supply, thus inking the design formed by themaster. Following this, a blanket roller, of rubber or the like, is moved over the inked master to pick up the inked design. The master roller then moves over the foil sheets on the fixture, transferring the inked design to the sheets. The latter are then further processed as mentioned above.

The holding of the thin foil sheets on the fiat surface of the fixture, in proper relation, presents a problem. One method used is to provide a plurality of pins projecting above the fixture and arranged to fit incorrespondingly located holes in the foil sheet. It should be stated that the usual clamping and handling methods are inapplicable due to the necessity of keeping the foil surface absolutely free of any foreign material such as moisture or grease. Such foreign substances may pick up the resist powder and thus interfere with accurate etching of the desired design.

While these pins are satisfactory as a means of holding the foil sheet against displacement, they must of necessity, project somewhat above the sheet, particularly when the latter is not mounted on a panel backing. Consequently, as

damage to the roll, several sets of similar located but spaced pins being encountered by the roll in one pass over the foil.

The present invention is directed to an improved arrangement for retaining the holding action of the pins while avoiding damage to the roller. To this end, the foil sheet supporting fixture includes spaced sets of vertically reciprocable pins which are normally biased to project through and above the foil. Means are provided for engagement by the roller whereby, as the latter advances over the foil, each set of pins is successively depressed just as the roller reaches the pins, and is released as the roller passes beyond the pins. As each set of pins is retracted, the remaining sets of pins hold the foil against displacement.

More specifically, the pins are mounted on bars extending transversely of the fixture beneath the undersurface thereof. These bars are spring biased upwardly to project the pins, and each bar has an upwardly projecting block mounted thereon at each end. These blocks each extend substantially in longitudinal direction from the pins. As the roller reaches the blocks, it depresses the bars before the roller is vertically aligned with the set of pins, and maintains the bars depressed until the roller has passed beyond the pins.

For a complete understanding of the invention principles, reference is made to the following detailed description of a typical embodiment thereof as illustrated in the accompanying drawing. In the drawing:

Fig. 1 is a top plan view of a foil supporting fixture;

Fig. 2 is a partial end elevation view of the fixture;

Fig. '3 is a side elevation view thereof;

Figs. 4 and 5 are transverse sectional views on the correspondingly numbered lines of Fig. 1;

Fig. 6 is a bottom plan view of the fixture;

Fig. 'I is a sectional view on the line l-'! of Fig. 6;

Fig. 8 is a sectional view on the line 88 of Fig. l; and

Fig. 9 is a somewhat schematic side elevation view of printing apparatus in which the invention may be incorporated. V 7

Referring to Figs. 1, 2 and 3, the foil supporting fixture I0 is mounted on the bed ll of the printing apparatus, being held in proper position by adjusting studs [2 threaded through angles [3 and provided with locknuts I4. Angles l3 are secured to bed ll bystuds I 6,. By suit- 3 able adjustment of the studs l2, fixture I is properly oriented on bed I I for correctly aligned cooperation with the blanket roller.

Fixture I0 is rectangular and generally in the form of a relatively thick plate which has a pair of parallel, longitudinally extending channels i1, I! in its upper surface, each near one side of the plate. Each channel I! is intersected perpendicularly by a plurality of short channels [8,

extending to the side edge of the plate, and by a plurality of shallower channels or grooves l9 extending inwardly of the plate.

Each set of channels ll, I8, 19 receives a lifting frame 20 comprising an elongated bar 2| lying in channel l1, lateral rods 22 connected to bar 2| and lying in channels l8, handle 23 interconnecting the outer ends of rods 22, and fingers 24 lying in and having less vertical extent than grooves l9. When frames 20 are in position, fingers 24 underlie a foil sheet or foil covered panel placed on the upper surface of fixtur [0. The frames are held disengageably in position by clips 25 secured in recesses 26 by bolts 21 and overlying bars 2!. The construction and arrangement of the frames will be clear from Figs. 4, 5, 7 and 8; a

The under surface of fixture I3 is formed with a series of laterally extending, longitudinally spaced parallel channels 3 l. Each channel slidably receives a pin supporting cross bar 30, each extending beyond both side edges of fixture (0, with the projecting ends of each bar having a block 33 secured thereto by studs 32. Blocks 33 as will be seen from Figs. 3, 4 and '7, extend above the upper surface of fixture [0.

Near either end of each channel 3!, a bushing 34 is mounted between the channel and the upper surface of fixture Iii. Bushings 34 act as bearings for sheet locating pins 35 set into bars 38. In the upper positions of bars 30, pins 35 project above the upper surface of mixture is to substantially the same extent as blocks 33. Bars are biased to the upper position by pairs of bowed rod springs 36 (Figs. 6 and 8) each extending through a bar and lying in narrow slots 43 intersecting channels 3| at right angles. The outer ends 37 of springs 36 bear on the upper surfaces of plates 38 secured to the undersurface of fixture 10 by studs 39.

Normally, all the pins 35 are in the upwardly projected position. When a foil sheet is to be placed on fixture [9, it is formed with holes located correspondingly to pins 35'. For example, and as seen in Figs. 4, 5 and 7, a panel'4l having foil sheets 45, on both surfaces, is-formed with holes 42 which extend through both foil sheets. Thus, the pins 35 extending through the holes 42 locate the foil coated panel properly on fixture l3 and retain it against lateral displacement thereon.

Additional holding efiect may be provided by vacuum devices connected to passages 43 extending through the fixture, such apertures being spacedly disposed within a zone co-extensive with the area. defined by the rear of the panel, the vacuum developed serving to maintain the panel in horizontal planar position.

The operation of the apparatus will be best understood from Figs. 1, 3 and 8. Fixture I0 is mounted on bed II in properly spaced relation to the master. panel or design 46. The apparatus is provided with an inking roller 41 and a blanket roller 48, thelatter being covered with or formed of relatively soft rubber. Suitable mechanism is provided for operating rollers 41 and 48 in predetermined patterns and in properly timed sequence.

In the first step, inking roller 41 moves from an ink supply, horizontally toward master 46, descends on the master, rolls thereover to ink the same, then lifts and retraces its horizontal path to the position of Fig. 9. Thereafter, blanket roller 48 moves horizontally to the right, descends to the right of master 46, rolls to the left thereover to pick up the inked design and moves horizontally to the left to roll over panel M on fixture [0 to imprint the design on foil sheet45.

During such rolling movement, as roller 48 approaches each set of laterally aligned pins 35, its surface first strikes the leading edges of the associated blocks 33, depressing the blocks and bar 30. The ends 31 of springs 36 slide outwardly on plates 38. Pins 35 are moved fiush with the surface of the sheet which is, meanwhile, held against movement by the other sets of pins, only one set of pins being depressed at a time. Progressive contact of the roller 48 with certain of the blocks 33 maintains the pins associated therewith depressed until the roller 48 has passed beyond the pins and releases the trailing edges of blocks 33.

The printed panels may be lifted from the fixture by releasing clips 25, and lifting the frames 20, the fingers 24 lying beneath the panel (Fig. 5) so that the panel need not be touched by hand.

Although in the specific embodiment illustrated in Figs. 4, 5 and 7, the product to be imprinted is illustrated as a panel of insulating material having foil sheets on opposing sides, which sides are imprinted, one after the other, with the apparatus in accordance with the method hereinabove outlined, it is within the province of the invention to imprint an unbacke'd foil sheet per se or an insulating panel having a foil sheet mounted on one side thereof, the essence of this invention being in the mechanism and maintaining a metal foil surface for imprinting of a circuit design thereon in advance of etching or other operations. Y

While a specific embodiment of the invention has been shown and described in detail to illustrate the application thereto, it should be understood that the invention may be otherwise embodied without departing from such principles.

What is claimed is:

1. In printing apparatus of the type in which a design carrying roller moves over a sheet mounted on the flat surface of a supporting and holding fixture, means for holding the sheet against lateral displacement on the fixture comprising, in combination, longitudinally spaced sets of laterally aligned pins mounted in the fixture arranged to engage correspondingly located holes in the sheet, means biasing the pins to project upwardly from the fixture surface, and means respectively connected with each set of pins and having portions disposed longitudinally in advance of each set of pins, the portions of said means being contactable by the roller, as it moves over the sheet, to successively depress each set of pins individually in'advance of engagement therewith by the roller and to maintain such set of pins depressed during passage of the roller thereover, the sheet being maintained in position by the other sets of pins.

; 2;. In printing. apparatus of the type in which a' design carrying roller moves over a sheet mounted on the fiat surface of a supporting and holding fixture, means for holding the sheet against lateral displacement on the fixture comprising, in combination, longitudinally spaced sets of laterally aligned pins mounted in the fixture arranged to engage correspondingly located holes in the sheet, longitudinally spaced means connecting and biasing each set of pins to project upwardly from the fixture surface, and means on said longitudinally spaced means disposed in the path of the roller in advance of the pins and contactable by the roller, as it moves over the sheet, to successively depress each set of pins individually in advance of engagement therewith by the roller and to maintain such set of pins depressed during passage of the roller thereover, the sheet being maintained in position by the other sets of pins.

3. In printing apparatus of the type in which a design carrying roller moves over a sheet mounted on the flat surface of a supporting and holding fixture, means for holding the sheet against lateral displacement on the fixture comprising, in combination, a plurality of longitudinally spaced bars extending laterally of the fixture and vertically reciprocable therein, spaced pins mounted on each bar and extending above the fixture surface to engage correspondingly located holes in the sheet, means biasing each bar upwardly to project its pins above the fixture surface, and means on each bar engageable by the roller to depress each bar individually as the roller approaches the pins to retract the pins and maintain them retracted during passage of the roller thereover, the sheet being maintained in position by the other sets of pins.

4. Apparatus as claimed in claim 3, in which said bars project laterally beyond the fixture and carry abutments on each end engageable by the roller.

5. Apparatus as claimed in claim 3, in which said bars are mounted in lateral channels in the undersurface of the fixture and project laterally beyond the fixture and carry abutments on each end engageable by the roller.

6. Apparatus as claimed in claim 3, including vacuum creating means connected to apertures in the fixture to maintain the sheet on the fixture.

ERNEST PENKER.

REFERENCES CITED The following references are of record in the file of this patent:

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