US3164088A

US3164088A - Machine for printing on sheets including expansible sheets such as textiles

Info

Publication number: US3164088A
Application number: US156012A
Authority: US
Inventors: Vechot Jacques Lucien
Original assignee: Alsacienne de Constructions Mecaniques SA
Current assignee: Alsacienne de Constructions Mecaniques SA
Priority date: 1960-12-07
Filing date: 1961-11-30
Publication date: 1965-01-05
Anticipated expiration: 1982-01-05

Description

. V/////7 //J/w//%//.A/////////w///4 9 Sheets-Sheet 1 -11 l Il FEP ,Ji L. VECHOT MACHINE FOR PRINTING ON SHEETS INCLUDING Jan. 5, 1965 EXPANSIBLE SHEETS SUCH AS TEXTILES Filed Nov. 30, 1961 Jan. 5, 1965 J L vr-:cHoT 3,164,088

MACHINE FOR PRINTING oN SHEETS INCLUDING EXPANSTBLE SHEETS SUCH AS TEXTILES Filed Nov. 50, 1961 9 Sheets-Sheet 2 FIG. 3

J. L. VECHOT MACHINE FOR PRINTING ON SHEETS INCLUDING Jan. 5, 1965 3,164,088

EXPANSIBLE SHEETS SUCH As TEXTILES 9 Sheets-Sheet 3 Filed Nov. 30, 1961 Jan. 5, 1965 J. L. VECHOT MACHINE FOR PRINTING ON SHEETS INCLUDING EXPANSIBLE SHEETS SUCH AS TEXTILES Filed NOV. 30, 1961 9 Sheets-Sheet 4 Jan. 5, 1965 J. L. vEcHoT 3,164,088

MACHINE FOR PRINTING oN SHEETS INCLUDING EXPANSIBLE SHEETS SUCH AS TEXTILES Filed Nov. 30, 1961 9 Sheets-Sheet 5 Jall- 5, 1965 J. L. vEcHo'r 3,164,088

MACHINE FoE PRINTING oN sHEETs INCLUDING EXPANSIBLE SHEETS SUCH AS TEXTILES Filed Nov. 30. 1961 9 Sheets-Sheet 6 9s i! 1 13e 4 l 'i l 7a 9g 97` l l o2 6e k/Jwss 9 101 -I 65 l' il ////H \\qp \5\ x Jan. 5, 1965 J. L. vEcHoT 3,164,088

MACHINE FOR PRINTING ON SHEETS INCLUDING EXPANSIBLE SHEETS SUCH AS TEXTILES 9 Sheets-Sheet 7 Filed Nov. 50. 1961 Jan. 5, 1965 J. L. vEcHoT 3,164,088.

MACHINE FOR PRINTING 0N SHEETS INCLUDING EXPANSIBLE SHEETS SUCH AS TEXTILES Filed Nov. 30. 1961 9 Sheets-Sheet 8 Jan. 5, 1965 J. L. vEcHo'r 3,164,088

MACHINE FOR PRINTING ON SHEETS INCLUDING EXPANSIBLE SHEETS SUCH AS TEXTILES Filed Nov. 30, 1961 9 Sheets-Sheet 9 United States Patent Gce ldi i'tatented dan. 5, 1955 MACHNE FR PRNTING N SHEETS MCLUD- ING EXPANSIBLE SHEETS SUCH AS TEXTELES Jacques Lucien Vechot, Lyon Rhone, rance, assigner to Societe Aisacienne de Constructions mecaniques, liant-I Rhin, France, a company of France Filed Nov. Sil, 196i, Ser. No. @6,0m Claims priority, application France Dec. '7, 1960 Claims. (Cl. lill-212) This invention relates 4to printing machines and more especially though not exclusively to machines for printing patterns on flexible sheet materials having substantial extensibility, such as textile `fabrics and .the like. The invention is also applicable however to the printing on materials of other character, includingpaper, plastics, sheet metal, and the like. g

Great diiculties have been encountered heretofore when it has been attempted to use rotary printing machines, e.g. offset machines, for the printing of patterns on extensible sheet materials such as fabrics. A chief difliculty has been due to the requirement for extreme accuracy in the developed length of the printing cylinders and rolls and in the maintaining of such length to the prescribed Vvalue during long periods of work. This has considerably increased the cost of machine construction and maintenance, and has required frequent replacement of the printing rolls, so that operating costs were prohibitive. The true source of the trouble lies of course in the lack of dimensional stability of fabrics in contrast to paper and other inextensible sheet materials.

. It is an obiect of this invention to provide an improved printing machine which Will be free of these difticulties and will enable perfect printing of any desired patterns, in one or more colours, to be performed on sheet materials of any reasonable character, including materials having substantial dimensional instability in one or more dimensions, such as textile fabrics.

In accordance with a basic aspect of the invention there is provided a printing machine comprising means for supporting a length of sheet material; means for intermittently advancing the supporting means in a longitudinal direction; a printing roll supported with its axis parallel to said longitudinal direction, means providing an inken pattern around the periphery of the roll, and means operable in timed relationship with the advancing means for moving the roll transversely across the surface of the material in substantially frictionless rolling engagement therewith during a stationary period of said material supporting means to transfer the pattern to the material.

The pattern providing means may comprise a plate positioned to one side of said sheet material and in the same general plane as it, the printing roll being adapted to take up ink from said plate and transfer it to said material in accordance with a selected pattern, means being provided for supplying ink to the plate in timed relationship with the general operation of the machine.

The supporting means may comprise an endless conveyor belt or the like. The means for intermittently advancing the conveyor preferably comprise a plurality of longitudinally reciprocable clamping units spaced along the conveyor and engageable for gripping the conveyor and the sheet thereon across the full Width of the she-e and actuator means cyclically operated for sequentially engaging the clamp units, advancing the clamp units in a longitudinal direction and then disengaging the clamp units and moving them back to their initial position. Preferably, at least one stationary clamp unit is further provided engageable for gripping the conveyor and inaterial across the full width thereof after the conveyor has been advanced one step and disengageable for releasing the conveyor and material prior to a further step of advance. v

With the machine of the invention, highly accurate printing operations can be performed, theV degree of accuracy being primarily determined by the precision achieved in the successive steps of advance of the .material, which latter can be effected with a very high degree of precision.

v The above and further objects, features and advantages of the invention will appear as thedisclosure proceeds, with reference to the accompanying drawings which illustrate a preferred form of embodiment given by Way of example but not of limitation. p

FIG. l is a schematic perspective view illustrating the basic principle of the machine.

FIG. 2 is an elevational View of one practical embodiment of a polychrome, dry offset printing machine constructed according to the invention;

FIG. 3 is a corresponding view in plan;

FIG. 4 is an elevational View of the intermittent con* f veycr advancing means;

FIG. 5 is a corresponding view in plan;

FIG. 6 is a largcr-scale View in section on line Vl-VI of FIG. 4.

FIG. 7 is a sectional view, on a further increasedscale, on line VII*VII of FIG. 4.

FIG. S is an enlarged sectional view on line VIII-VIII of FIG. 3.

FIG. 9 is a corresponding plan view.

FIG. 1G is a section o-n line X-X of FIG. `9.

FIG. 11 is a view in section on an enlarged scale, on the line XI-XI of FIG. 3, or on line XI-XI of FIG. 12.

FIG. l2 is a plan View corresponding to FIG. 11.

FIG. 13 is a section on line XIII-XIII of FIG. 12. Y

FIGS. 14n, 14b and 14C are simplied partial views illustrating the operation of `the printing roll carriage; and

FIG. 15 is a schematic view of the central sequencing control of the machine. n

Referring to the simpliiied view of FIG. 1, an improved offset printing machine comprises a support in the form of an endless conveyor band 1 of flexible substantially inextensible material trained about end drums l1 and 12 and provided with means, not shown, for advancing the conveyor stepwise in a longitudinal direction as shown by arrow fl. The band 1 may be natural or synthetic rubber provided with reinforcement of natural or synthetic tibers, glass wire or the like for rendering the conveyor band substantially inextensible. Alternatively the support may be provided in the form of a plurality of parallel endless chains or belts. The sheet of material to be printed on is shown at l@ `and is secured to the outer surface of the conveyor by any suitable means, such as adhesive, or by means of clamps, or pins spaced along the length of the conveyor and projecting from .its outer surface.

The machine further includes a set of Wetter rolls 3, a set of inldng rolls 2, a pattern plate or block 4 supported on a bedplate 5, and a rotary blanket or printing roll 6.

The wetting and inking rolls and the pattern plate are mounted to one side of the support assembly described',

andthe rolls are arranged for displacement parallel to the direction f1 so as to engage the upper surface of the pattern plate. AThe printing roll dis mounted for displacement transverse to the direction f1. f

In operation, in a rst stage of the operating cycle the i conveyor 1 is advanced one step in the direction f1,

while at the same time the wetting rolls 3 and inking rolls 2 are displaced in the same direction on to and over the surface of the plate 4 so as to apply ink to said surface. During such displacement the printing roll 6 is positioned above the upper leaf of the .conveyor 1 and out of engagement with the surface of web 1t) attached thereto.

In a succeeding stage of the cycle, the inking and wetting rolls having performed their function are returned to their initial positions as shown, while the blanker or printing roll 6 is rolled across the surface of the pattern plate 4 so as to take up ink deposited on the prominent areas of the plate.

In the next stage the printing roll 6 is displaced transversely to roll across the surface of the sheet 1t) in the transverse direction thereby to transfer to said surface the ink pattern taken up by it from the pattern plate. The cycle described is repeated step by step each step of advance of the conveyor may correspond in length to the longitudinal dimension of the pattern on the pattern plate. It will be noted that the accuracy of the transfer or printing action is determined almost exclusively by the accuracy of the step-by-step advance of the conveyor.

While the arrangement schematically described above referred more especially to the form of offset printing process in which the pattern plate is first wetted then inked so as to transfer ink to the prominent areas of the plate, it is equally applicable to intaglio oifset processes in which ink is deposited on to the plate and then wiped oit with scraper means from the prominent-areas so as to transfer the recessed pattern from the plate on to the sheet of material. Further, the same principle can be applied to the so-called dry oiset process, in which case only the inlring rolls 2 would be used. Moreover, in applying the invention to multi-colour printing processes, it would simply be necessary to provide a number of similar printing assemblies each of which may be similar to that schematically shown in FIG. l, and spaced longitudinally along the sheet, With all the printing assemblies being operated in synchronism. Correct register is easily achieved if the pattern plates are correctly positioned on the bedplates and the step-by-step advance of the conveyor is accurately adjusted.

A practical embodiment of a polychrome, dry offset printing machine based on the principle of the invention presented above will now be described in detail with reference to FIGS. 2-15, in which components corresponding tocomponents shown in FIG. l are designated with the same references as in that ligure.

Referring -rst to FIGS. 2 and 3, there is shown an endless supporting conveyor belt 1 to the outer side of which is arliXed the sheet of flexible material 1l) to be printed on, and which belt is trained around the end drums 11 and 12. The drums are journalled on shafts 14 and 15 mountedin opposite ends of a machine frame 16. The embodiments described related to a polychrome printing process involving black and three colours, and hence comprises four

similar printing assemblies

21, 22, 23 and 24 spaced along the length of the conveyor. For imparting intermittent step-by-step advance to the conveyor in the longitudinal direction shown, by arrow f1 there is provided stepping mechanism including four clamping

trucks

26, 27, 28, 29 (see FIGS. 4 and 5) spaced longitudinally of the conveyor and each adapted to be reciprocated a limited distance over a corresponding length of

longitudinal track

31, 32, 33, 34. Each clamping truck is provided with clamping means adapted to engage a related area of the side edge of the upper leaf of the belt'l as will be presently described in detail. All four trucks are reciprocated in unison over their respective tracks; for this purpose a foremost one 26 of the trucks is connected by a connecting rod 35 With a piston reciprocating in a double-acting iluid pressure actuator V1, while all four trucks are interconnected by intervening connecting rods 37, 3S, 39 so as to be driven in unison. The reciprocatory stroke is determined by engagement of a stop 41 projecting from the bottom of truck 26 with each of two longitudinally spaced

abutments

42 and 43 preferably made adjustable relatively to the frame 16.

The four trucks are similarly constructed, each comprising a generally rectangular body 46 (FIG. 6) having four flanged rollers 47 journalled to its under surface for engagement with the rails forming the aforementioned track 31. The flat upper surface of the body 45 of each truck serves as a lower clamping surface for engaging the under side of the belt 1, and cooperates with an upper clamping member 48 supported on the truck by way of vertical rods slidable in a pair of vertically disposed double-acting hydraulic cylinders V2 arranged at opposite sides of the plate 46 as clearly shown in FIG. 6. As there shown, a line 51 is connected with the lower ends of both actuators V2 and a line 52 is connected with the upper ends of both actuators; valve means, not shown, are provided for alternately connecting line 51 to the pressure source and line 52 to exhaust for raising the upper clamping member 48 to release the belt 1, and connecting line 52 Ito the source and line S1 to exhaust to clamp the belt 1. The operation of the stepping mecha-Y nism described is briey as follows:

With the clamping trucks in the positions shown in FIGS. 4 and 5, pressure oil is supplied to the actuators V2 of all the trucks through line 52 to lower the tops 48 thereby to clamp the upper leaf of belt 1 (and sheet material l@ affixed to it) at four spaced points along the'length of the belt. Simultaneously or a short time later pressure oil is applied to a line 54 (FIG. 4) connected with the rear end of stepper actuator V1 whereby all four trucks are displaced forward until abutment of stop 41 with the front abutting surface 43, carrying the conveyor `belt forward in their displacement. The pressure oil valving is then reversed so as to connect line 51 of each actuator V2 with the pressure source to release the conveyor and connect line 55 of actuator 'V1 with the pressure source whereby all four trucks are re turned to their rearmost positions with stop 41 abutting rear abutment surface 42 as shown in FG. 4. During the return movement of the clamping trucks the belt 1 is released from the clamping means. However, more positively to prevent any tendency for the belt to be partially carried back by the trucks through friction, a. stationary clamping unit is preferably provided, generally designated 56 in FGS. 4 and 5 and shown in de-f tail in FIG. 7. The stationary clamp Se is very similar in structure to each of the movable clamps constituted by the trucks such as 2e except that its body 45a instead of being mounted on rollers is fixedly secured to the frame 16. The stationary clamp 56 comprises a vertically movable top member 48a supported on the piston rods of vertical actuators V3 (corresponding to actuators V2 of FIG. 6) which are connected at their lower ends with oil: line di) and at their upper ends with oil line 59.

Oil lines

51 and 5? may be interconnected in common and lines 52 and 6l) may be interconnected in common so that the stationary clamp is actuated to releasing condition when the movable clamps are actuated to clamping condition, and vice versa.

Each of the end drums 11 and 12 is rotatably mounted around the related stationary shaft 14 or 15 by way of a freewheel device 61 or 62 (FIG. 4) so as only to permit rotation of the drums in the sense that causes advance of the conveyor belt in direction f1 but prevents reverse rotation. Moreover, each

end drum

11 and 12 is provided with electromagnetic brake means generally shown at 63, 64 (see FIG. 5). These are safety features serving to prevent any undesired motion of the belt at times when uch motion might result in faulty printing or other deects.

The printing assemblies will now be described with especial reference to the assembly 21 (FIGS. 2 and 3). Each such printing assembly comprises a frame structure including a stand 65 (also see FIGS. 8, 9 and l0) for supporting the inking rolls, a stand 66 for supporting the bedplate 5 supporting a pattern plate or block, and a stand 67 for supporting the printing roll 6. The stand 67 comprises spaced upright members and a bridge structure supported thereby which extends transverse to the direction of the belt and over and across the upper surface Vand S6 secured coaxially with the rolls' 72. and 74.

snes-,oss

of the conveyor belt, so as to allow the printing roll 6 to be rolled across the surface of the work as later described in detail. The stands 65 and 66 are positioned to one side of the belt and their general arrangement will become apparent from the drawings as the disclosure proceeds. All three stands 65, 6o and 7 are iixedly related to the conveyor frame structure 1e as by being firmly imbedded on common foundations therewith.

The inlring assembly supported on stand 65 is generally conventional in a dry otfset process and will only be described in brief. Said assembly comprises a container 71 providing a store of ink and an associated roll 72 directly contacting a store of inl; and an associated roll 72 directly contacting the ink in the container, a swinging ink-transfer roll 73, a foremost roll 7d, an intermediate roll 75, a pair of stationary inking rolls 76 and 77, and three spreader rolls 7d, 79, and 311. All the rolls except the swinging roll 73 are permanently rotated during operation of the machine by means presently described; moreover the three spreader rolls in addition to their rotation are axially reciprocated in the usual way for smoothly spreading the ink across the surface of the inking rolls.

The means for driving the rolls in rotation comprise an electric motor M mounted on the frame 65 and driving through reducer gearing not shown an output screw shaft formed with two threaded sections 83 and dil of opposite pitch, respectively engaged by worm gears The remaining rolls are driven off the roll 74 through a train of gears not shown, the primitive circumferences of which gears would coincide, in the drawing of FIG. S, with the circumferences of the rolls since all the rolls must be so driven as to roll with respect to one another without relative circumferential slippage, and hence all the rolls must have equal peripheral linear velocities and revolve in opposite senses las from one roll to the roll next in the series. The drive gearing is housed in recesses formed in the uprights of the frame 65. To provide the aforementioned axial reciprocation of the spreader rolls 78, 79 and Sti, there is used in the example herein described mechanism including a grooved ring 96 (PEG. l0) se-y cured coaxially with the spreader roll 73, and engaged by driving fork 97 which is pivoted at a lixed point 9S to the stand 65 and having its end remote from that engaging the grooved ring 96, engaging a helical groove formed in the periphery of a cam 99. The cam 59 is secured to a gear 161 which meshes with a gear lll?, which in turn engages a suitable one of the gears of the train serving to rotate the remaining rolls of the inking assembly as above described.

The relatively stationary inking assembly just described and including the stationaryV inlring rolls 76 and 77 cooperates with a movable inking assembly or ink transfer assembly comprising three inlring rolls 87, S8, il? which are reciprocated as will soon be described to transfer inlr from the

stationary rolls

76, 77 to the surface of the pattern plate 4 supported on stand 66. For this purpose the transfer rolls 37, S8, S9 are journalled on a carriage 92 mounted on rollers 93 engaging the rails 911, he' which are secured in part to the upper surface or" stand 65 and in part to the upper surface of stand 66 (also see PEG. lil). The carriage 92 has side portions extending below the track 941-95 and having rollers 1&4, 1%5 journalled thereon which engage the under side of a pair of rails 94, 95 serving to prevent the carriage 92 from deraiiing. As shown, carriage 92 comprises a pair of side ilanges 166, 1117 ot' trapezoidal form held in parallel spaced relation by tubular spacers 1%, 19.

Each movable inking roll or transfer roll 37, 83, 89 is supported from the carriage 92 so as to be vertically displaceable relatively to it a limited amount. Thus roll S7 is journalled -at its ends between a pair of arms 111 112 pivoted about horizontal pivots 113, 11din the side anges of the carriage. Similarly each of the rolls 2:8 and S9 is journalled between the pair ofarms 11S-116 and 117-118 pivoted on the pivots 121-122 and 123-124 respectively. For reciprocating the transfer carriage 92 there is provided a reversible electric motor M1 supported from the stand 65 and carrying on its output shaft a drive pulley connected by a V-belt 126 with a driven pulley 127 fixed on a transverse shaft 123 journalled in the stand 65 and carrying the pair of

bevel gears

131, 132 on its respective ends. Meshing with these gears are bevel gears 133, 13d secured on longitudinally extending

lead screws

135, 136 on which are engaged respective nuts 137, 13S secured to the outer sides of the respective side flanges 106 and 1tl7 of the carriage 92. The lead screws 135, 136 have their one ends journalled in bearings 141, 142 secured to frame 65 and their other ends journalled in bearings 143, 1114i secured to the frame or stand 66.

ln operation, when motor M1 is rotated in one or the other direction, the lead screws 135, 136 are rotated through the transmission means described to traverse carriage 92 in a corresponding longitudinal direction relative to the frame. With carriage 92 positioned at the right hand eX- tremity of its stroke according to FlGS. 8 and 9, the transfer rolls S7, 3S, 89 are positioned in engagement with pattern plate Il, while at the other end of the displacement of the carriage the lirst two transfer rolls 87 and d8 are in engagement with the upper stationary inking roll 76 and the third roll S9 is resting upon the remaining upper stationary inlring roll 77. Rotation is imparted to the movable inlring rolls by their frictional engagement with the stationary inking rolls at `the left hand end o-f their reciprocatory stroke, so that when said movable rolls reach the right hand end of their reciprocation in engagement with the pattern plate 4, they already possess a linear peripheral velocity which is substantially equal tothe velocity required for a slip-free rolling engagement of said rolls with the surface of the pattern plate.

Now turning to the printing roll 6 (see FIGS. 2 and 3), this roll is supported on a carriage 146 (better shown in FGS. 1l to 13) made up of a pair of spaced

slide flanges

147, 143 interconnected by

tubular spacers

151, 152, 153 and 154 and mounted on

rollers

155, 156, 157 and 15S rolling on

rails

161, 162 secured to the under surface of the corresponding stand 67, e.g. to the vertical Webs of the horizontal channels comprising the frame members of said stand in the embodiment shown. The side tlanges 147, 143 further carry

lower rollers

163, 164 journalled on

pivots

165, 167 and engaging the lower edges of the

rails

161, 162 to prevent derailment of the upper rollers. The printing roll 6 is journalled at its ends in

lever arms

168, 169 interconnected by a tubular spacer 171 and freely pivoted on pivots 172, 173 to the respective side flanges 147, 148. A double-acting hydraulic actuator V4 has one of its component members, eg. the cylinder 17d, attached to a support 174 carried by the upper spacer 154 of the carriage and its other component, the piston rod 175, connected to the spacer 171 so that on application of pressure fluid to a line 176 or a line 177 connected to the respective ends of the actuator the printing roll 6 will either be moved to the raised position lshown in full lines in FlG. ll or will be lowered to the chain-line position. ln this latter position the roll 6 is in rolling engagement with the surface of printing plate 4 or with the surface of the work lil supported on the belt 1, which in turn is supported on a table 178 (FlG. ll) secured to bridging stand 67.

For reciprocating the carriage 146 over its rails and rotating the roll 6 there is provided a reversible electric motor M2 supported on the carriage. A belt drive comprises a belt 131 trained around a pulley 179 mounted on the motor output shaft and a pulley 132 secured on a transverse shaft 1&3 journalled between the flanges 147, 14S of carriage 146. Shaft 1%3 also has secured to it near its opposite ends the gears 134 and 185 which mesh respectively with a pair of racks 156 and 187. These racks are supported by and slidable relatively to the

respective rails

161 and 162 for reasons later described. Longitudinal reciproca'tion of the racks relatively to the rails is effected through the respective double acting hydraulic actuators V5 (see FIG. 3) to the opposite ends of each of which pressure fluid is selectively applicable through

lines

191 and 192. When motor M2 is energized to rotate in one or the opposite sense, the belt and gearing transmission means described operate to impart to the carriage 11ia displacement in a corresponding direction over the

rails

151 and 162.

To improve the accuracy of the printing process and avoid the development of any torsional stresses in the printing roll 6, the roll 6 is positively rotated and for this purpose has a pair of

gears

193 and 194 secured coaxially with it at its opposite ends, which mesh with respective gears 195 and 196 secured to the aforementioned pivot shafts 172 and 173. Said shafts further carry gears 12'? and 198 which mesh with the aforementioned gears 1M and 135 respectively, engaging the racks 18115 and 187.

The pitch diameters of the gears described are so determined with respect to one another that as the carriage 146 moves over the rails, the surface of printing roll 6 rollingly engages the surfaceV of the pattern block i or the surface of the web 1li, depending on the position of the roll, without any relative slippage and friction between the engaging surfaces. Since the gears 195 and 1% are coaxial with the shafts 172 yand 175 serving as pivots for the arms lofi and 159 supporting the printing roll, it will be obvious that said gears remain constantly in mesh with the

gears

193 and 1% secured to the opposite ends of said rolls, regardless of the angular position of the rolls, so that the setting of the roll with respect to the racks is at all times retained at a strictly constant value. Since it is essential that the teeth of the gears 193 and 124i should be positively prevented from contacting the pattern block or the surface of the work at any time, the outer diameters of the

gears

193 and 194 must be made smaller than the outer diameter of the printing roll 6. This makes it impossible to provide `an arrangement wherein said gears would be in direct rolling engagement with the racks, since in order that such rolling engagement should be 'slip-free, the pitch radii of the gears would then have to be made equal to the outer radius of the printing roll and the outer tips of the gear teeth would then project beyond the periphery of the roll.

It will be appreciated that the arrangement described above has the advantage of achieving apositive, slipfree rolling of the printing roll upon its rails while preventing such unacceptable projection of gear teeth.

In the operation of the machine, the motor M is permanently driven to impart continuous rotation to the stationary inking rolls 76 and 77, and related components. The remaining movable components of the machine are operated in timed relationship in accordance with an automatic sequencing programme, by timed actuation of the hydraulic actuators and electric motors described, so as to accomplish the desired operating cycle. This phase of the invention will now be described with reference to an exemplary embodiment.

As shown in FIG 15, the sequencing control for the various components is derived from a common camshaft 211 which is permanently driven in rotation from an electric motor M3 by way of a vari-able speed device generally designated 212 and a worm-and-worrngear reducer 213. Secured in spaced relation on the camshaft is a rst set of cams, herein tive, 221 through 225, which are engaged by 'actuator plungers protruding from respective hydraulic control valves generally designated D1 through D5. Each valve has a pressure inlet and a pressure outlet connection, and a pair of motor connections. All five pressure intake connections are connected to a common pressure line 241 connected with the outlet of a pump 242 (eg. gear pump) drawing 4hydraulic liquid from a sump 243, and all five outlet connections are connected in parallel l to a common outlet line 24d delivering into the sumo. The motor connections of each of the D valves are connected to the respective ends of a related one of the double-acting hydraulic actuator' cylinders described earlier.

Specifically, the motor connections 54 and 5S of valve D1 are connected with the opposite ends of actuator V1 controlling the intermittent advance of the conveyor belt 1.

Lines

51 and 52 from valve D2 connect with the ends of each of the actuators V2 controlling the clamp devices mounted on the trucks 26-29, the lines 59, 6u from valve D3 connect with the actuators V3 controlling the stationary clamp unit 56. Lines 176 and 177 from valve D4 connect with the actuator Vd controlling the vertical movements of printing roll 6; and the

lines

191 and 192 from valve D5 connect with the actuator VS controlling the longitudinal displacement of the racks 13e and 18'? which determine the relative angular setting of the printing roll.

Camshaft 211 further carries a set of cams 231. 232 and 233 engaged by actuator plungers projecting from respective electric switch devices C1, C2, C3. Each switch device has connections leading in parallel to a power source, herein three-phase alternating source 246, and cach switch device has a further pair of conductors connected therewith and leading to the energizing circuits of the respective electric motors or actuators earlier described. Specically switch C1 is connected through lines 251 to motor M1 serving to reciprocate the movable inl;- ing rolls 87, 8S, S9; switch C2 is connected by lines 252 with the motor M2 reciprocating the printing roll carriage 146; and switch C3 is connected by lines 253 with the electromagnetic actuators operating the conveyor belt drum brake devices 63 and d4.

Camshaft 211 further carries an indexing disk 258 which carries indicia, not shown, cooperating with a fixed marker 259 for indexing the various stages of an operating cycle, which cycle corresponds with one full revolution of the camshaft 211. Such operating cycle will now be described.

On termination of a preceding cycle of operation, the inking roll drive motor M is operating as is also the sequencing camshaft drive motor M3, while motors Mi and M2 are deenergized. rlfhe movable inking rolls S7, 55%, 89 are positioned at the left hand end of their reciprocatory stroke, as shown in dotted lines in FlG. 8, in engagement with the surfaces of stationary inking rolls 76 and 77. The printing roll 6 is raised above the surface of the work. The brakes 63 and 64 of the conveyor drums are applied. The trucks 26, 27, 2S, 29 are in their leftward or retracted position shown in PIG. 4, and their clamping devices are engaged to clamp the upper flight of belt 1 and the Work 10. The stationary clamping unit 56 is also applied at this time. The

racks

136 and 187 are positioned at the right-most end of their displacement as shown in FIiG. 14C.

As the camshaft 211 commences a fresh revolution, it operates the actuator plungcrs of hydraulic valves D1- D5 and switches Cil-C3 to produce the following sequence of events:

Valve D3 is actuated to supply pressure liquid through line 6G to actuator V3 so as to release the stationary clamp member 5o (FIG. 4,1.

Switch C3 is actuated to deenergize the electromagnetic actuator for releasing the drum brakes 63, 64 (FlG. 5).

Valve D1 is actuated to supply pressure liquid through line 54 to actuator V1 to displace the actuator piston to the right (FIG. 4). The conveyor belt 1 is therefore drawn by the clamping trucks 26-29 to effect one step of advance.

Switch C1 energizes motor M1 through lines 251 in a sense to impart rightward movement to the carriage 92 carrying the inking rolls 87-83 (see FIGS. 8 and 9). The said rolls loaded with ink from their previous engagement with the stationary inldng rolls '76, 77, now assume the positions shown in full lines in FIGS. 8 and 9 and deposit ink onto the surface of pattern plate 4.

As the conveyor belt 1 reaches the end of its step with stop 41 engaging the ixed abutment 43, valve D3 is actuated by its associated cam to supply pressure oil through 59 to the stationary clamp 56 to engage said clamp about the upper leaf of the conveyor belt and work; substantially simultaneously switch C3 operates the electromagnetically actuated brakes 63 and 6d to their applied condition; the work is thus arrested in position to receive a fresh print.

Valve D2. is actuated to supply oil via line 51 to the actuators V2, opening the clamp devices of trucks 26-29. Valve D1 is actuated to supply pressure oil via line 55 to actuator V1, causing the trucks 2er-29 to recede leftward.

During this receding movement of the trucks switch Cl is actuated to impart a further lertward movement to the inking-roll-supporting carriage 92 (FIGS. 8 and 9), returning rolls 87-89 to the positions shown at 87a, 3&1, 39a (FIG. S) where they engage the stationary inking rolls '76 and 77. Also substantially concurrently switch C2 is actuated to energize motor M2 so as to displace the printing roll supporting carriage lid-t from the position shown in FEGS. 3 and 14C where it overlies the work, to the position shown in FIG. 14a overlying the pattern plate 4. Throughout its displacement the printing roll is retained in its raised position out of engagement with either the work or the printing plate by the action of actuator Vl supplied with pressure oil through line YK from Valve D4.

As the printing roll o reaches the full-line position shown in FiG. 14a however, valve D4 now supplies oil to actuator V4 through line 177 to lower the printing roll into contact with the surface of block 4. Switch C2 is actuated to reverse the rotation of the motor M2 which thereupon moves the printing roll carriage ide rightward (FIGS. l1 and 14o) while the printing roll 6 moves in frictionless rolling engagement with the surface of block 4 from the full-line position to the dotted-line position shown at 6a.

The width of the pattern plate or block 4 substantially equals 4the developed peripheral length of the printing roll and equals the width of the material lib to be printed on. The relative setting of the roll 6 as later explained, is such that a longitudinal axial groove 2% provided on the printing roll is presented substantially in register with each of the side edges of the block A, and each of the side selvedges of the work material thereby to ensure proper engagement and disengagement of the roll with and from the block, and a proper printing of the pattern on the work.

The carriage 146 supporting the printing roll proceeds on its course towards the worn, and on reaching the work selvedge, substantially in the full line position 6b of FIG. 145, the groove 29 is still positioned in register with the selvedge, as will presently appear. The printing roll therefore engages the work cleanly and accurately; moreover the groove Zt? ensures that the roll will clear any selvedge clamps or pins that may oe used in attaching the work to the conveyor beit. Thereafter the printing roll rolls in a frictionless, slipfree manner over the surface of the work and transfers thereto the pattern formed by the ink taken up by the roll from the pattern plate. As the roll 6 reaches the end of its stroke at 6c (FIG. 14C), after having completed nearly one full revolution in contact with the work, switch C2 is actuated by its earn to deenergize the motor M2, and valve D4 is actuated by its cam to operate actuator V4 to raise the printing roll. The cycle is now completed.

The reason for the reciprocation of racks N6 and 1.87 is the following. If the distance between the adjacent side edges of the pattern block 4- and the work lo could be made strictly equal to the circumferential length of the printing roli 6, the racks could be made stationary. However, it is convenient to place the block d at a shorter distance from the work conveyor in order to reduce the lateral dimensions of the machine, and in any case accurate dirnensioning would be diiicult to maintain. This dithculty is overcome by the provision of the sliding rack arrangement described. The length of longitudinal travel of the racks is made equal to the distance E between the adjacent edges of plate or block 4 and the work it?. If such distance is greater than one half the developed length D of the printing roll circumference (D being the roll diameter), then the length of displacement of the racks can be, and preferably is, reduced from the value E to the value irD-E. The result will ybe exactly .the same, with the rotation of the roll being'simply foreshortened by one complete revolution.

With the arrangement described, when the racks are displaced by their actuators VS (controlled by the carnactuated valve device DS) by the amount speciiied above, then the roll on reaching the selvedge of the work (position 6b) will be at exactly the same angular setting relative to the work selvedge yas the relative angular setting of the roll relative to the edge of plate 4 at the time the roll rst started moving away from said plate. The racks are then returned from the positions shown in FIG. 14C to theirposition shown in FIG. 14a during the return displacement of the printing roll towards the plate, and preferably while the roll is moving over the gap between the work and block 4.

.in the polychrome printing press shown, it will be understood that all of the individual colour printing units (four in the example shown) are constructed as described above for unit 2li, and all the units are operated in syn- -chronisrrr A common sequencing control unit of the kind shown in FG. 15 may be used for controlling the synchronous operation.

It is apparent lthat .between adjacent printing units ample room can be made available for mounting any-desired drying, curing and/or other processing appliances, such as blowers, radiating 4heaters and the like. it may be indicated in this connection that in a printing process according to the invention substantially less ink need be deposited on the work than in comparable dry offset printing processes of conventional type, e.g. using printing frames, so that correspondingly less drying or curing is required to set the prints. I

Various modications may be conceived and departures made from the details vof the machine Shown and described without departing from the scope of the invention. As one example, the double-acting iiuid actuator V4 operating the up-and-down displacements of the printing roll may be replaced with a single-acting device in case the weight of the said roll with its associated parts is great enough to permit of substituting gravity for fluid pressure as the downward force acting on the printing roll. However, if a double-acting cylinder V4 is used as in the embodiment here described, the said actuator should be so dirnensioned and the iuid pressure so selected as to ensure obtaining the proper pressure of the printing roll upon the work suitable for each particular printing operation. As a general rule, large-pattern prints would involve the use of higher pressures while liner and more delicate patterns will require lower pressure.

The amount of ink collected at the surface of the movable inking cylinders 87, 8S, S9 depends on the time such cylinders dwell in contact with the stationary ink transfer cylinders 76, 7'7. It is, accordingly, desirable to provide s ome means of adjusting such dwell time, and this can be done by means of any suitable timing device of conventional character; conveniently the dwell time may be adjusted within a range of from one to tour seconds or so. The possibility of thus adjusting the inl: transfer time constitutes a distinct advantage over rotary textile printing machines of the conventional type in which the only way of controlling the quantity of ink deposited at each printing operation is by adjusting the doctor blade of enea-,oss

the ink store and/or the operating rate ot the swinging ink transfer roll corresponding to roll 73 of the present drawings. If desired, moreover, the amount of ink transfer can be increased by a provision for double transfer.

While the invention has been described with reference to a textile printing process, it is to be understood that its teachings are applicable to printing processes on carriers other than textiles, eg. paper, plastics, including rigid sheet materials such as metal sheet. The invention is applicable to type printing. In snch an application (and in other applications), the pattern plate d of the described embodiment would be replaced by a smooth plate and the printing roll 6 made to carry a cylindrical type block (or pattern block) with raised type thereon.

In the speciication and claims, the word ink (and its derivatives) is to be construed as including any transerable printing medium or agent.

What 1 claim is:

1. A printing machine comprising means for supporting a length of sheet material; means for intermittently advancing the supporting means in a longitudinal direction; a plate member having a generally ilat pattern surface stationarily supported to one side ot said material and substantially in a common plane therewith, inlsing means including a movable inking roll for supplying ink to said plate surface; said inking roll being movable across said plate member in a direction parallel to said longitudinal direction, an ink transfer member movable in a transverse direction from a position engaging said plate member to take up ink therefrom and-into engagement with said sheet material to transfer said ink thereto; and means operable in timed relationship with said advancing means for moving said inliing roll and said transfer memlber so as to ink said plate member and transfer ink from said plate member to said material in accordance with said pattern during a stationary period of said material supporting means.

2. 1n a printing machine, the combination comprising work supporting means providing a iiat work surface; a dat plate member spaced from said Work surface and substantially coplanar therewith; means supplying ink to said plate member; a roll member adapted to take up ink selectively from said plate member in accordance with a pattern and transfer said ink to said Work surface; and means for supporting and displacing said roll comprising: a carriage supported for movement from said plate to 'said work and back; .means supporting said roll from said carriage and movable between an operative position in which a generatrix of the roll lies on the common plane of the plate and work surfaces for transferring ink from the former to the latter, and a retracted position; a rack parallel to the path ot movement of the carriage; a gear journallecl on the carriage and meshing with the rack; power means for rotating said gear; a second gear secnrcd coaxially with the roll and having an outer radius substantially smaller than that of the roll; and a gear train interconnecting both gears, the drive ratio of the gearing so predetermined that the roll when in said operative position is rotated in substantially frictionless, slipfree rolling engafrement with said plate and work surfaces.

3. in the machine claimed in claim 2, means mounting the rack for longitudinal displacement; and means iinparting to the rack a displacement corresponding to the distance between adjacent sides of said plate and work surfaces during movement of said carriage from the time the roll has disengaged one ol said surfaces to the time the roll has engaged the other surface.

4. The claimed in claim 2, wherein said means supporting the roll from said carriage comprise a support structure having said roll journalled thereto about one and pivoted to said carriage about another axis for rotational movement of said support structure and roll about a pivot axis between said operative and inoperative positions; and wherein said gearing comprises a pair of ears rotatable coaxialiy about said pivot axis and respectively meshing with said first and second gears.

5. rhe machine claimed claim l, wherein said inl(- ing means comprise least one stationary inlting roll supported with its axis transverse to said longitudinal direction to one side of Said supporting means; means supplying inl; to said stationary roll and means for continuously rotating said stationary inl-Ling roll; and at least one movable inking roll supported With its axis parallel to that of said stationary inking roll; and means for displacing said movable inling roll in timed relationship with said advancing means between a position in engagement with said stationary inking roll to take up inl; therefrom and into rolling engagement across said plate member for delivering inl: tnereto.

Reterences Cited in the tile of this patent UNITED STATES PATENTS 188,370 reland Mar. 13, 1877 1,934,751 Von Webern Nov. 14, 1933 1,980,968 Ellunge et al Nov. 13, 1934 2,308,107 Robbins et al. lan. 12, 1943

Claims

1. A PRINTING MACHINE COMPRISING MEANS FOR SUPPORTING A LENGTH OF SHEET MATERIAL; MEANS FOR INTERMITTENTLY ADVANCING THE SUPPORTING MEANS IN A LONGITUDINAL DIRECTION; A PLATE MEMBER HAVING A GENERALLY FLAT PLATEN SURFACE STATIONARILY SUPPORTED TO ONE SIDE OF SAID MATERIAL AND SUBSTANTIALLY IN A COMMON PLANE THEREWITH, INKING MEANS INCLUDING A MOVABLE INKING ROLL FOR SUPPLYING INK TO SAID PLATE SURFACE; SAID INKING ROLL BEING MOVABLE ACROSS SAID PLATE MEMBER IN A DIRECTION PARALLEL TO SAID LONGITUDINAL DIRECTION, AN INK TRANSFER MEMBER MOVABLE IN A TRANSVERSE DIRECTION FROM A POSITION ENGAGING SAID PLATE MEMBER TO TAKE UP INK THEREFROM AND INTO ENGAGEMENT WITH SAID SHEET MATERIAL TO TRANSFER SAID INK THERETO; AND MEANS OPERABLE IN TIMED RELATIONSHIP WITH SAID ADVANCING MEANS FOR MOVING SAID INKING ROLL AND SAID TRANSFER MEMBER SO AS TO INK SAID PLATE MEMBER AND TRANSFER INK FROM SAID PLATE MEMBER TO SAID MATERIAL IN ACCORDANCE WITH SAID PATTERN DURING A STATIONARY PERIOD OF SAID MATERIAL SUPPORTING MEANS.