US2333239A - Spool truck for screen printing apparatuses - Google Patents

Description

Nov. 2, 1943. H. FLEISHER ETAL SPOOL TRUCK FOR SCREEN PRINTING APPARATUS Filed Sept. 6, 1941 5 Sheets-Sheet 2 I a NVENTORS Harry flasher mum- | l l I I l I I I I I I I I I I i i l I I I I lll'lv' )1 on 4 IIIIIII l E w mm 'IIL BAN 12 N h ATI'ORN EY Nov. 2, 1943. Lz s ETAL 2,333,239

SPOOL TRUCK FOR SCREEN PRINTING APPARATUS Filed Sept. 6, 1941 5 Sheets-Sheet s Nov. 2, 1943.

H. FLEISHER ET'AL 2,333,239

SPOOL TRUCK FOR SCREEN PRINTING APPARATUS IGI Filed Sept. 6, 1941 5 Sheets-Sheet 4 1943- H. FLEISHER EI'AL 2,333,239

SPOOL TRUCK FOR SCREEN PRINTING APPARATUS Filed Sept. 6, 1941 5 Sheets-Sheet 5 INVENTOR Harry 1"; c-z'sher. G egrge H. 72Zlezz.

ATTO RN EY Patented Nov. 2, 1943 UNITED STATES PATENT OFFICE SPOOL TRUCK FOR. SCREEN PRINTING APPARATUSES Harry Fleisher, Watertown, Conn., and George H. Tillett, Jackson Heights, N. Y., assignors to Roto-Matic Screen Printer, Ltd., New York,

N. Y., a corporation of New York Application September 6, 1941, Serial No. 409,868

2 Claims.

. screen printing apparatus disclosed in,a prior Patent No. 2,210,474 issued August 6, 1940, to George H. Tillett, entitledfColor printing web."

This application is a continuation in part of our prior application, Serial No. 364,604, filed November 7, 1940, entitled Screen printing apparatus.

One object of this invention is to provide means to secure a web-carrying spool, mounted on a movable carrying truck, in accurate alin'ement with the screen printing apparatus, whereby the area of web to be printed will be in proper transverse registry with the stencil screen.

Another object of this invention is to provide an improved apparatus for applying designs upon flexible webs of the above nature, which will be relatively inexpensive to manufacture, simple in construction, easy to operate by relatively unskilled labor, compact, ornamental in appearance, and very efficient and durable in use.

With these and other objects in view, which will appear as the description proceeds, there have been illustrated in the accompanying drawings several forms in which the invention may be conveniently embodied in practice.

Briefly, the screen printing apparatus of this invention includes a central table for supporting a screen frame and a pair of spools, one carrying a roll of web to be printed, and the other serving as a take-up roll for the web after printing. The web to be printed is adhesively fixed to a carrier belt which is fed manually intermittently from one spool below the screen to be wound upon the other spool. Provision is also made of marginal spacer strips secured to the carrier belt so that when said belt is wound in spiral condition, the color paste freshly printed upon the web will be kept out of contact with the adjacent layer of said web, whereby smudging of said color will be prevented, and said fresh color will be given a chance to dry. The spacer strips also serve to separate the successive layers of the web and provide between them a drying space through which a stream of dry air may be forced.

By winding the printed web in spiral form upon the take-up spools, the material maybe stored while drying or curing in the minimum of space as compared to the former methods of drying printed webs on elongated flat tables or suspending said webs in festoons or loops. The compact coiled web-carrying spools of the present invention are movably mounted on caster trucks so as to facilitate the feeding of the web back again through the printing apparatus for applying additional colors or printing the web at different areas from those originally printed.

In the drawings: Figure l is a front elevational view of the improved screen printing apparatus embodying the invention.

Figure 2 is a broken end elevational view of the same.

Figure 3 is an enlarged and broken transverse section taken on the line 3-3 of Figure 2 and shows a top plan view of the spool truck aligning and clamping means.

Figure 4 is a side view of the parts shown in Figure 3 Figure 5 is a broken top view of one corner of the spool truck and machine frame shown in unclamped and partly separated position.

Figure 6 is a perspective view of a spool truck with a spool mounted thereon.

Figure '7 Ba broken sectional view of 'an assembled spool and truck with a modified form of clamp mechanism for detachably connecting them together.

Figure 8 is a side view of the same.

Referring now to the drawings wherein like reference numerals designate like parts throughout the several views, the-numeral [0 denotes a flat table top which, in this instance, is suitably supported by four corner uprights, or legs, ll, l2, l3, and M. The front uprights II and [2 are connected and braced by horizontal bars. I5, I

I6, and I! while the rear uprights I3 and II are likewise connected and braced by similar horizontal bars located behind said bars l5, l6, and I1, and concealed thereby as viewed in Figure 1. The front uprights II and 12 are connected and braced at the top by horizontal side bars l8, l9, and 20, and the uprights II and I4 are braced by similar side bars concealed thereby. At each end of the apparatus, provision is made of upright bars 2| extending from the lower horizontal bar I5 to the upper bar l1, and a short vertical bar 22 extends at each side' from the intermediate horizontal bar l9 to the lower bar 20 (Figure 2).

Provision is also made of a pair of horizontal shafts 23 mounted in and extending between the front uprights II and I2, and the rear uprights l4 and I3, respectively. Each of said shafts 23 is journaled at each upright H, H, I3, and I4,

in brackets 24 (Figures 1 and 2), each of which is vertically adjustable in and is secured to the respective upright by a bolt 23 passing through each shaft 23 and a sprocket 23 is secured upon the rear end of said shaft. The shafts 23 are extended at their front ends 23 beyond the uprights II and I2, and said ends are preferably made hexagonal in cross-section to removably receive a manually-operated crank handle 33.

The table top I 3 extends rearwardly beyond the comer uprights II and I4, as at 3| and is provided with a pair of transversely-spaced apart bearing brackets 32 and 33 adjustably mounted thereon by means of bolts 34 and 33 passing through a common elongated slot 33 in each bracket and through the table top extension 3|, (Figures 1 and 2). An angle piece 31 secured to the table top extension 3| has a screw 38 threaded therethrough into engagement with each of the brackets 32 and 33 to permit them to be held in any desired position and to prevent said brackets from moving rearwardly when the machine is being operated.

Stencil screen Provision is also made of a swingable stencilsupporting frame, (Figures 1 and 2), comprising end rods 33 and 43, and side bars 4| and 42-the rear end rod 43 being pivoted in bearings carried by the brackets 32 and 33, respectively. The rods 33, 43, 4| and 42 are connected together at the corners of the stencil frame by four angle blocks 43, thus maintaining the frame in rectangular shape.

Four vertically disposed posts 46 extend upwardly-one from each angle block 43-to support side rods or tracks 41 and 48 which are spaced above the side rods 4| and 42, respectively, and are parallel thereto. An elongated angle bar 43 extends between the side rods 4| and 42 adjacent the front end of the screen supporting frame, and a similar angle bar 33 extends between the rods 4| and 42 adjacent the rear ends thereof. The angle bars 43 and 33 are adiustably secured to the respective rods 4| and 42 by clamping brackets 3|, and are arranged to have one of their angle portions horizontal and the other vertical. By means of the brackets 3|, the angle bars 43 and 33 may be adjusted longitudinally in the direction of web travel along the rods 4| and 42 to position the stencil frame supported thereby in the desired location.

The horizontal base portions 32 of the angle bars 43 and 33 extend toward each other and form opposing seats for a rectangular stencil screen,

which, in this instance, is made of four narrow wooden strips 33, 34, 33, and 33, and secured together at their adjoining ends. A printing stencil sheet 31 is stretched across the bottom of the stencil screen, said sheet 31 being preferably made of specially treated silk having the desired perforated design formed thereon through which the thin color paste may penetrate and be applied by a squeegee to the web W placed thereunder. In this instance, the front and rear strips 33 and 34 of the stencil screen are removably seated on the horizontal portions 32 of the angle bars 43 and 33 of the swingable stencil screen supporting frame.

The stencil frame, comprising the strips 33, 34, 33, and 33 is seated'in the carrying frame, comprising thebars 33, 43, 4| and 42, and may be brought into exact register with thedesign on the stencil screen by adjustment of the vertical limit arm 38, (see Figure 2), of an adjustable guide bar having a horizontal arm 33 which is secured to the table top l3.

The stencil screen, 33, 34, 33, and 33 may be manually-lifted from the underlying web W whenever it is desired to shift the web by swinging its carrying frame 33, 43, 4|, and 42 upwardly about the hinged connection of the rods 43 in the bearings 43 and 44 as a pivot.

Provision is also made of means to manually lift the stencil screen carrying frame 33, 43, 4|, and 42, and such means comprises a pivoted foot treadle 83 which, as shown in Figure 2, is connected to the front rod 33 of the screen carrying frame through a system of links and levers arranged with a "mechanical disadvantage whereby a comparatively small movement of the treadle 83 will move said frame a relatively large amount.

The foot treadle 83 is pivoted to a cross bar 82 extending between the lower side bars 23, and provision is made of a short upstanding link 83, which loosely connects the forward part of the treadle 83 with a long vertical link 84. The upper end of the long link 84 is loosely connected to ashort vertical link 83, which in turn is pivoted to an inclined arm 83 at a point closely ad,- jacent the lower fixed end 31 thereof. The end 81 of the arm 33 is pivoted to the front intermediate upright 2| between a pair of angle blocks and the upper end 33 of the arm 83 is connected by a chain, 3| (see Figure 2) reeved over a pulley 32, supported on the rear surface of the upright 2|, said chain passing downwardly from said pulley and being connected to a post 33 secured to a vertical slide 34, which is adapted to loosely embrace the upright 2|.

The slide 34 is connected to the lower end or an upstanding plate 33 (Figures 1 and 2), which carries a short horizontal shaft 33 at its upper end. The shaft 33 extends beyond the'sides oi the plate 33 and has rollers 31 Journaled on each end thereof. The rollers 31 engage blocks 33 secured to the underside of the front screen frame rod 33 and serve to reduce friction. By means of this construction, it will be seen that, when the operator steps on the treadle 33, force will be transmitted through the links 83, 34, 83, and 36, chain 3|, slide'34, plate'33, to the rollers 31, causing the front end of the stencil screen carrying frame to swing upwardly and lift the stencil screen out of contact with the web W. To assist the operator in this operation, counterweights 33 may be hung upon the arm 33 adiacent its upper end 33. The stencil carrying frame is engaged at its forward end by a pair of curved strips I34 and I33 (see Figures 1 and 2) which serve to guide the angle blocks 43' as this frame is lowered into place.

The web W is adapted to be fed across the table top l3 under the stencil screen 31 from one side of the printing apparatus to the other. In order to avoid any stretching or movement of the web W, it is temporarily secured upon a carrier band, or belt, I33, preferably constructed of heavy flexible paper, by means of a non-drying, sticky adhesive which may be composed, for example, of a mixture of China clay and glycerine. By the use of this adhesive, the carrier belt |33 may be used repeatedly before replacement is necessary, due to the fact that it may be stripped therefrom without damage to the belt I33 of the web W. In most instances, only the outer fibres at the undersurface of the W are impregnated by the adhesive.

Provision is also made of a pair of spa r strips IM and I02 disposed beneath both margins of the carrier belt I00, and preferably cemented thereto, (see Figure '7). It will be understood that said strips IN and I02 may, if desired, be

. riveted to the carrier belt I as by eyelets, within the scope of the invention. The combined web W, carrier belt I00, and spacer strips IM and I02, are adapted to be guided across the table top I0, by means of a pair of transverse grooves I03 and I04 respectively, formed in the upper surface of said table top I0, (see Figure 2). When the web W and the carrier strip I00 are wound into a spiral coil upon a spool I05, (as shown in Figures 1 and 2), it will be understood that the belt I00 will be spaced apart in successive layers by the strips IOI and I02 at its edge, thus providing an air space therebetween, protecting the color paste printed on the web W and preventing smudging of the table top I0 thereby. The color will thus be permitted to penetrate uniformly into the web and produce a .sharp and distinct reproduction of the design thereon. The edges of the web carrier belt I00 'outside the web are preferably coated with shellac or other suitable material to seal them against moisture and afiord additional stiffening.

The color paste employed in the screen printing apparatus is adapted to be forced through perforations in.the stencil screen 51 onto and into the web W by means of a squeegee blade I08, preferably made of soft rubber and having its upper edge set into a recessed strip I01, The strip I01 is hinged as at I08 to another strip I09, located above it, which strip I08 is adapted to be clamped between a pair of transverse angle bars H0 and III by a pair of thumb screws H2. The angle bars H0 and III are secured to the forward ends of a pair of short horizontal slide members H3 and H4 of inverted U-shape crosssection. The legs of each inverted U-shaped member straddle the parallel side tracks 41 and 48 and thus guide the squeegee blade I06 in its manual reciprocation by the operator who grasps a relatively long handle rod II secured at one end to the cross bars H0 and III, as shown in Figures 1 and 2. It will be noted that the inverted U-shaped guiding members H3 and H4 d not actually rest on the tracks 41 and 48, but the weight of this structure and the squeegee blade I08 is imposed directly upon the stencil screen 51 so as to cause the color paste to pass therethrough and upon the web beneath it. The pressure of the squeegee blade I06 upon the screen may be increased if desired by the use of suitable ring shaped weights II6 surrounding a pair of vertical posts II1 extending upwardly from the guide members II4.

In operation, the squeegee blade I06 will be lifted at each end of its stroke and moved and lowered at the opposite side of the mass of color paste so as to push it in the reverse direction. This operation is readily accomplished by swinging the handle rod I I5 upwardly and causing the rear ends H9 and I of the guide members H3 and H4 to engage the tracks 41 and 48 which act as fulcrums therefor.

When the printing operation is completed, the squeegee blade I05 will be raised away from the stencil screen 51 and maintained in such raised position, while the stencil screen is also lifted and the web shifted to bring a new unprinted portion into registry with the screen. For this purpose,

provision is made of a pair of transversely spaced apart standards I2I and I22 secured to the table top I0 at the rear of the stencil screen supporting angle bar 50. Each of the standards I2I and I22 has a horizontal rearwardly extending arm I23, I24, and forwardly extending angle arm I25, I26, respectively. The arms I23 and I24 extend outwardly in opposite directions and carry rollers I21, and the arms I25 and I26 extend inwardly toward each other and carry rollers I28.

When it is desired to support the squeegee blade I06 up out of contact with the stencil screen 51 at the rear end of its stroke, it will merely be necessary to tilt the handle II5 upwardly to cause the rear ends IE9 and I20 of the guide members H3 and M4 to be disposed under the rollers I21, and the rear cross bar III to be disposed above the rollers 828. The web-carrying belt with the web W adhering thereto may then be fed across the table top I0 from the feed spool I05 on one side of the printing apparatus to the take-up spool I05 on the other side. Each of the spools I05 has a hollow shaft I29 extending from its rear end, and has a sprocket I30 detachably secured to said extending end by a set screw I3I. A chain I32 is reeved over the sprocket I30 and the sprocket 28 on the hand wheel shaft 23, whereby rotation of the hand wheel 21 on the take-up side of the apparatus will cause the web W to be fed across the table top Whom the feed spool I05.

In order to insure accurate printing, indicating lines are marked at spaced intervals along the edge of the carrier belt I00, and a single line is marked on the table top I0. These marks when in alignment indicate to the operator that the web W has been properly positioned in accurate registration for another printing operation.

Spools As herein shown, a pair of identical spools I05 are provided, which may be selectively used for feeding and taking-up of the web. Each spool is permanently mounted upon a truck I35 having casters I36 whereby it may be wheeled toward and away from the apparatus to carry the web into and out of printing position. In order to insure accurate registration of the printed designs on the Web, means are herein provided on each side of the printing apparatus for alining the spool carrying truck I35 with said apparatus. The alining means above referred to includes two pairs of resilient arms I31, I31a extending outwardly from the side end uprights I2, I3, and II, I4. The arms I31, I31a are each curved outwardly to facilitate the movement of the side base bars I38 and I39 of the truck I35 into engagement therewith and to guide the feeding spool so that the web W to be printed will be in correct transverse re istry with the stencil screen when it is fed into printing position.

In order to lock the spool truck I35 in operating position, provision is made on each of said alining means of a toggle mechanism comprising a lever I40 having one end pivoted as at I4I to the adjacent resilient arm I31, I31a. A handle I42 at the other end of the lever I40 is provided to manipulate the same. Provision is also made of a thin rod I43 having a hooked end I44 adapted to catch into elongated slots I45 provided in the side base bars I38 and I39 and piv otally secured to the lever I40 intermediate its ends, said rod I43 passing through a vertical post I46 which is arranged to rotate in the lever I40. A coiled, spring I41 surrounds the rod I43 and reaots between the post I46 and a washed held on the outer end of the rod I43 by lock nuts I49 and I50.' When it is desired to hold the truck in the locked position (as shown in Figure 3), the hooked end I44 of the rod I43 will be connected to the truck side bars I38 and I39 by engagement inethe slot I45 nearest thereto and the levers I40 will be swung from the open position, shown in Figure 5, into the truck-locking posi tion as shown, in Figure 3. If desired, an additional slot I45 may be used so that the trucks may be readily reversed and either side thereof selectively applied to the printing apparatus.

Web-drying apparatus While the apparatus is being operated, and a freshly printed web W is being wound continually upon the take-up spool I05, a constant flow of dry air will be directed against the surface of the web on said spool by means of a duct II leading from a central motor driven air blower I52 (see Figure 1). Additional drying may also be obtained by means of an auxiliary blower, not shown, to force dry air into the hollow spool shaft I29, which air will be caused to flow outwardly through perforations I53 therein and between the layers of the spiralcoil of web W wound thereon.

As is clearly shown in Figures 1, 3, 4, and 6, the side base bars I38 and I39 of the spool carrying truck I35 are joined together by front and rear base bars I56 and I51. Moreover, a pair of vertical brackets I58 and I59 of trapezoidal shape extend upwardly from the side bars I38 and I39 of the truck and have Journal blocks I60 mounted upon the upper edge of each of said brackets I58 and I59 to support the ends of the shaft I29 of the spool.

which serve to guide the base bars I39, I99 and facilitate the insertion of the spool truck into its proper aligned position with respect to the central printing table.

By means of this construction it will be seen that the spool truck may readily be. released from the printing. table by first depressing either of thepedals I14 and pulling that side of the truck outwardly away from said table. The truck may then easily be rolled out from engagement .with the printing table.

If desired, rubber bumpers I92 may be attached to the end base bars I2 and I3 of the table to absorb the shock when the truck is forcibly, engaged with the printing table.

Operation The operation of the above described screen printing apparatus is substantially in accordance with that disclosed in the above-mentioned Patent No. 2,210,474. In brief, the operation is as follows:

Assuming the squeegee blade I06. is held in raised position by the rollers I21-and I20 (see Figure 5), the stencil screen frame will be swung upwardly by depressing the treadle 00. The webcarrying belt I00 will then be drawn across the table top' l0 from the feeding spool ill with the spacer strips IOI and I02 guided by the grooves I03 and I04, respectively. The free ends of the web-carrying belt I00 will then be attached to a take-up roll I05, which has first been locked Provision is also made of a pair of collars I6I and I62 secured on the shaft I29 by set screws I63 whereby the spool may be held in any desired lengthwise adjusted position with respect to the truck and to thus permit alignment of the flanges I64 and I65 of the spool with the web-carrying strip I00. The flanges I64 and I65 are secured to the spool shaft by circular ribbed plates I66 and I61, respectively. I

In the modified form of the invention, shown in Figures '7 and 8, a novel clamping mechanism is disclosed for detachably connecting the truck I35 to the central screen printing table. This mechanism comprises a pair of levers I10, I10 on each end of the table pivoted tovthe legs I2 and I3 by horizontal bolts I1 I, Hi, said levers having downtumed catch hooks I12, I12 for engagement with the bases of triangular wedge-shaped lugs I 13 secured tothe extremities of the base bars I38, I39, respectively, of the spool truck I35.

The opposite ends of the levers I10 are provided with rectangular pedals I14, I14, and said levers are also provided with vertical cross bars I15, I15, having eyes I16 at their upper ends for connection to one end of inclined coiled springs I11, the other ends of said springs being attached at eyes I18 formed in the-legs I2 and I3 of the printing table, so as to cause said spring to exert 'a continuous tension upon said lever tending to urge it towards the position shown in Figure 8. The opposite ends of the cross bars I15 are provided with horizontal stop ears I19 which prevent the levers I10 from swinging beyond the position shown in Figure 8.

Provision is also made of a pair of fixed outturned resilient curved guide strips I80 and I8I secured to the printing table below the levers I10 in place at the other side of the printing apparatus. The hand wheels 21 will then be turned to bring the first mark on the carrier belt into alignment with the mark on the table top II. whereupon the stencil screen holding frame will be lowered to cause said screen to engage the web W. The squeegee blade I06 will then be lowered upon the rear end of the stencil screen 51 and the proper quantity of color paste will be then placed upon the screen 51 in front of the blade I06, which may then be pulled forwardly by means of the handle H5.

When the squeegee blade I06 is in its forward position after having traversed the length of the screen 51, it will be lifted by tilting the handle II5 upwardly and placed in front of the mass of color paste, and then pushed rearwardly to spread the same along the screen 51. After the desired number of strokes of the squeegee blade I06 have been made, said blade will be latched in its raised position as above described. The stencil carrying frame will be swung upwardly by means of the treadle 90. The web W will then be fed along, the desired amount, to bring the next desired indicating mark on the webcarrying belt into registry with the mark on the table top I0. This procedure will be continued until the web has been completely unrolled from the feed spool and wound up on the take-up spool.

After the spool of unstenciled web has been unwound from the feeding spool, printed, and wound up on the take-up spool, the latter may be unlocked and rolled away from the printing apparatus for drying or other treatment. It will then be returned to the printing apparatus on either side thereof, and the previous take-up roll will then serve as the feed roll-it being merely necessary to shift the crank handle 30 to the other shaft 23 to operate the feeding mechanism and take-up mechanism, as described above.

While there have been disclosed in this specification several forms in which the invention may be embodied, it is to be understood that these forms are shown for the purpose of illustration only. and that the invention is not to be limited to the specific disclosures, but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new and for which it is desired to secure letters Patent, is:

1. In a latch mechanism for holding a webcarrying spool in accurate registry with a screen printing table, a resilient outwardly curved arm connected to said table and having guiding engagement with a movable truck upon which said spool is mounted, a toggle lever connected at 1 one end to the free end of said resilient arm,

and an elongated rod slidably connected to the HARRY FLEISHER. GEORGE H. TILIEIT.

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