Abstract: A printer capable of printing a multicolor image with a single pass of a paper or similar recording medium includes a plurality of print drums. Drum drive gears each are mounted on a particular print drum such that the print drum is replaceable. The print drums are interlocked to each other by rotatable members including relay gears meshing with the drum drive gears, timing pulleys fixed to the relay gears, a timing belt, and pulleys for adjustment. Each rotatable member has teeth the number of which is selected such that the number of rotations of the rotatable member to occur in a single period of the print drums is an integral multiple of the number of rotations of the print drums.

Abstract: Disclosed herein is a stencil printer including a rotatable paper pinch drum with a cutout, a plurality of printing drums, and a position control unit. The cutout is formed in a portion of the outer peripheral surface of the rotatable paper pinch drum along a generating line in the axial direction of the drum. The plurality of printing drums have axes parallel with an axis of the paper pinch drum and disposed around and near the paper pinch drum so that the printing drums rotate in synchronization with the paper pinch drum in the opposition direction from the direction of rotation of the paper pinch drum. Each of the printing drums includes a stencil paper clamper which clamps one end of a paper stencil wound around the outer peripheral surface of the printing drum and an internal press roller which supplies ink to the stencil paper.

Abstract: A printing control apparatus for controlling a stencil printing machine (50, 100), wherein a stencil sheet, which is made on the basis of image data, is wound around a printing drum (25; 125, 126) with which a print sheet (34; 141) is held in pressured contact to perform a stencil printing operation, provides the stencil printing machine with image data representative of an image to be reproduced as an object, and printing order information representative of a page order in which the printing operation is performed using image data, an ink color for the printing drum to be used, and a timing in which one printing drum is replaced with another one. In accordance with the printing order information, the ink color contained in image data is detected and an order for each page to be printed is determined on the basis of a user's print request to execute the printing operation according to the page order and to reduce the number of times the printing drum is replaced with.

Abstract: A user PC 120 for controlling a stencil printing machine 1, having a plurality of exchangeable printing drums, wherein respective printing drums are mounted with respective perforated stencil sheets which are formed by a stencil-making processing section 104 on the basis of image data, and a print sheet is held in press contact with the plural printing drums to perform a stencil printing process with first and second stencil-printing processing sections 105, 106 is disclosed as having a registering function to register printing ink colors to be used for printing with the respective printing drums by enabling reading-in of a printer driver and to store useable ink color information, a function to produce display data to display contents of the ink-color designating information produced by the designating section for the respective printing drums.

Abstract: A stencil capable of accurately transferring a picture with a plurality of colors by a person without skill. This stencil includes a plurality of die seal papers from which parts of a picture are die-cut at different positions from each other as cutting die portions which are associated with each other to form a completed picture. The bottom faces of the die seal papers are adhesive faces. The die seal papers are bonded and fixed to each other in the required ranges of the base portions thereof. After the lower die seal paper is put on an object to color the object via the cutting die portion, the lower die seal paper is peeled from the object and cut away from the base portion thereof to form a polychrome picture.

Abstract: In the multi-drum type rotary stencil printer adapted to drive a plurality of printing drums altogether in synchronization with one another by a common drive mechanism, when one of the printing drums is placed out of engagement with a printing, a degradation of ink is anticipated in the temporarily rested printing drum due to its excessive stirring during an idling rotation. In order to avoid such an ink degradation, a clutch is incorporated in a route of transmitting a driving force from the common drive mechanism to each of the printing drums, so that the transmission of the driving force through each of the route can be selectively interrupted.

Abstract: On each of plural printing drums (25, 26) in a stencil printing machine (1), a stencil sheet (11) made corresponding to printing data is rolled. The machine (1) for a stencil printing process, in which a printing paper is pressed on each printing drum and the used stencil sheet is disposed, has a mode designation section (101) and a controller (102). The section (101) designates whether or not a stencil printing process is performed for plural printing information including common printing data. The control section (102) controls the stencil making process, the stencil disposing process, and the stencil printing process for the printing information. When the printing information includes common printing data, the controller (102) controls the printing drum on which the stencil sheet for the common printing data is rolled so that the stencil making and disposal processes are not performed.

Abstract: A printer of the present invention includes drive pulleys each being mounted on a particular print drum.

Abstract: In a printer including a plurality of print drums sequentially arranged in a direction of sheet conveyance, a member causative of noticeable variation in load during printing is driven by a driveline assigned to one print drum that is connected to a main drive source. The printer reduces synchronization errors between the print drums ascribable to variation in load and therefore reduces offset ghosts while making the most of the advantages of a timing belt type drive system.

Abstract: A screen printing machine has article supports for articles to be printed, a displacement mechanism for displacing the article supports in succession around an endless path of travel and printing stations distributed along the path of travel and each having a printing head. The displacement mechanism has drive members engageable with the article supports for displacing the article supports, a reciprocating drive operable to reciprocate the drive members to and fro along the endless path to advance the articles in succession to the printing stations, and actuating devices for displacing the drive members into and out of engagement with the article supports. The article supports are vacuum tables communicating with a vacuum duct through a member sliding between flexible members extending along the duct.

Abstract: A new platen for use with a printing machine, and preferably for allowing automatic unloading of a printed article from a support surface of the platen is disclosed. The disclosed platen includes a structure for attachment to the printing machine, a support surface, and a gripping area disposed about the support surface to allow an automatic unloader to grip and remove an article from the support surface. The support surface is preferably rectangular having gripping areas proximate to each corner of the surface. The gripping areas are preferably notches within the support surface itself, but may also be in the form of a ledge with notches disposed along a portion of an edge and attached to the support surface.

Abstract: A printer including a plurality of print drums and capable of producing, e.g., color printings is disclosed. When a closed position sensor responsive to a door outputs a close signal and when a drum sensor assigned to a print drum to be mounted outputs an absence signal, a controller controls drum drive sections such that a mount/dismount drive section assigned to the print drum to be mounted takes the position corresponding to a mount position. Also, in response to a mount position signal output from a mount position sensor, the controller controls the drum driving device such that the mount/dismount drive section stops at the position corresponding to the mount position. The printer allows an operator thereof to mount the print drums without pressing, e.g., mount/dismount keys each time and thereby saves time.

Abstract: A method of operating a screen printing machine of the type where a number of garments supported on pallets sequentially move past a series of printing stations. In order to allow a sufficient delay between each print application the garments pass around the stations several times and in each lap only some of the colors are printed. The sequence is controlled by tracking the first garment and by activating counters at each active print head as the first garment arrives. The program allows for one process to complete while another commences and thus provides improved productivity.

Abstract: A method of making a heat transfer from an image for application to a T-shirt or other piece of cloth is disclosed. An image is scanned to create a computer image represented by a computer readable image file. The image is separated into a plurality of colors using a computer to create a separated image. A plurality of plates is created from the separated image corresponding to each of the colors. The plates are printed on film to create a plurality of color separation films corresponding to one of the plurality of colors. Mesh screens are treated with a photoemulsion. The color separation films are then placed on the mesh screens and light is applied to the mesh screens A portion of the photoemulsion hardens in the light and a second portion of the photemulsion covered by the printed matter on the color separation films remains soft. The mesh screens are washed to remove the second portion of the photoemulsion. Ink is applied to a piece of transfer paper through the mesh screens.

Abstract: A stencil printer includes a plurality of ink drums spaced from each other in the direction of paper conveyance and each having a respective master wrapped therearound. An upstream ink drum and pressing means movable into and out of contact with the upstream ink drum define an upstream print position. A downstream ink drum and pressing means movable into and out of contact with the downstream ink drum define a downstream print position. An intermediate conveyor is located between the upstream print position and the downstream print position for conveying a paper carrying an image printed at the upstream print position toward the downstream print position. A distance which the paper moves from the upstream print position to the downstream print position is longer than a distance between the upstream print position and the downstream print position. Defective printing is reduced even when the peripheral speed of the upstream ink drum and that of the downstream ink drum are different from each other.

Abstract: A printing press (10) including a pallet arm assembly (20) having a first arm extension (26) and a second arm extension (28) and an adjustable coupling (30) therebetween. Adjustment of coupling (30) adjusts the lateral and vertical position of a pallet table (22) carried by the pallet arm assembly. The printing press (10) also includes an angularly adjustable press arm bracket mount (60) that is mounted on a rotatable wheel (16) that carries multiple press arm assemblies (18). Adjustment of the angular position of bracket (60) assists in lowering press arm assembly (18) into a yoke gate (36) mounted on pallet arm assembly (20). Press arm assemblies (18) also include over-center spring mechanisms (90) that place a coil spring in compression rather than tension and include an enclosure (104) for capturing the coil spring for increased safety.

Abstract: A drying/curing apparatus for a rotary screen printing machine includes a carriage supporting a flash curing unit. The curing unit has a height or thickness that is less than the gap between the workpiece platen of the printing machine and the printing screen. The drying apparatus includes a structure attached to a print station of the printing machine that is configured to permit reciprocation of the curing unit across a substrate supported on the workpiece platen after an ink layer has been applied to the substrate and the platen has been retracted from the print screen. The curing unit includes a plurality of heat generating elements, such as high power quartz lamps, that are directed toward the ink layer on the substrate. The curing unit includes an insulator plate disposed between the curing lamps and the printing screen of the printing machine when the curing unit travels across the workpiece platen.

Abstract: A screen printing system has multiple screen cassettes stored in a magazine and a first screen cassette is transferred from the magazine into a printing station. A motorized pallet conveyor conveys a plurality of substrates, each of which is loaded one of a series of pallets of the conveyor, into and from the printing station and about an endless path. After printing the first image or color, the first screen cassette is returned to the magazine and a second preregistered screen cassette is brought to the printing station with a second image or color being printed on each substrate as the pallets carrying the substrates are conveyed into and from the printing station. Preferably, the substrates and pallets are maintained in a horizontal position while they travel laterally, downwardly and upwardly when moving along the endless path.

Abstract: A machine including a printing cylinder (6) engaging two stencil cylinders (7, 18) for printing at least two non-overlapping areas in different colors using the one printing cylinder. One of the stencil cylinders (7) is conventional and enables silk-screen printing in a first area. The other cylinder (18) includes raised portions provided with a stencil for printing one or more further areas different from the first area while preventing the rest of the stencil cylinder (18) from contacting the printing cylinder and particularly the area(s) printed by the first cylinder (7).

Abstract: A screen printing machine has article supports for articles to be printed, a displacement mechanism for displacing the article supports in succession around an endless path of travel and printing stations distributed along the path of travel and each having a printing head. The displacement mechanism has drive members engageable with the article supports for displacing the article supports, a reciprocating drive operable to reciprocate the drive members to and fro along the endless path to advance the articles in succession to the printing stations, and actuating devices for displacing the drive members into and out of engagement with the article supports.

Abstract: A stencil printer capable of printing a multicolor image on a sheet of the present invention includes a plurality of drums arranged side by side in an intended direction of sheet transport at a preselected interval. Ink of particular color is fed to the inner periphery of each drum carrying a respective master around its outer periphery. An intermediate transport device transports a sheet from an upstream drum to a downstream drum. A controller controls the sheet conveyance speed of the intermediate transport device and/or the print conveyance speed of the downstream drum in accordance with the size and/or the position of the sheet. The printer allows a minimum of double printing and misregister to occur by making up for a delay of transport of the sheet to the downstream drum.

Abstract: A preferred screen printing press (10) includes a plurality of print stations each having a print head (64) in registration with a platen (26) with the print head and platen being shiftable between a spaced position and a print position, and further includes a substrate handling assembly (20) for shifting a substrate from one printing station to another. The preferred press (10) also includes a plurality of curing stations each including a curing platen (28) and a heater for heating the platen to a selected ink curing temperature. The preferred print head (64) includes a lifting mechanism in the nature of air cylinders (96, 98) for applying a constant lifting force to the rearward edge of a print screen (94) in order to lift the screen (94) under this constant force and as the squeegee (104) moves therealong.

Abstract: A balloon printing apparatus for printing an image on the outer surface of a number of inflatable elastic balloons of the type defining a main body and a neck opening allowing access into the main body. The apparatus comprises: a conveyor device movable in a closed path in an intermittent manner; a plurality of nozzles spacedly carried by the conveyor device, insertable into a balloon neck opening and for inflating a balloon; as many balloon supporting frames as air nozzles, carried by the conveyor device, each nozzle adjacent to a corresponding frame, each frame sized to partly surround and support the main body of an inflated balloon installed on the adjacent nozzle with a portion of the inflated balloon protruding from the frame. The body remains in a stable position relative to the conveyor device while the inflated balloon is transported by the nozzle and frame through the closed path.

Abstract: In a method for forming a duplicate image by reading an original image from an original sheet and forming a duplicate image according to the original image, to allow the designation of a number of regions for forming duplicate regional images, from an overall image, with desired color separation or other various attributes to be carried out accurately, promptly and simply by mounting the original sheet only once on a digitizer or the like without regard to the number of processes of forming a duplicate image, a plurality of regions designated on a single original sheet are stored in a storage device such as computer memory, either the designated region stored in the storage device or the region other than the designated region is defined as an effective region, a duplicate image of only the effective region is formed for a first process of forming a duplicate image, only the region other than the effective region for the first process of forming a duplicate image is defined as a new effective region, and a du

Abstract: A mobile printing shop (300,301,302) is disclosed including a turret style printing machine (10) having a plurality of folding radial arms (30,70,170) and a vehicle (300, 301, 302) for transporting the machine (10).

Abstract: A method and apparatus for automatically adjusting the location of a screen frame holder of a silk screen printing head in the x-axis to maintain accuracy in registration of color-to-color in a multi-color printing process due to the inaccuracies in indexing of an indexing transport member.

Abstract: A process and system for applying or treating a graphic image on a substrate by using heat and pressure. The system is comprised of a frame having a plurality of supporting members and a reciprocally mounted heated platen extending from a first member, and a reciprocally mounted support having a pair of raised bars thereon reciprocally mounted on a second member. The heated platen and the raised bars of the support are first sequentially moved, and then simultaneously brought into contact with a supporting pallet and substrate, so as to condition, emboss, fix, form, or shape a surface of the substrate, or an image on the substrate, to thereby improve the quality thereof, or of further graphic images applied thereto.

Abstract: An improved stencil set and method of applying stenciled designs to a surface is provided. A plurality of stencil sheets are provided wherein each stencil sheet has a distinct portion of the design represented by cutout areas in the sheet and remaining portions of the design visibly printed on the sheet. The sheets are used in sequence to apply the design to a surface and, in the preferred embodiment, with each sheet, the portions of the design not being immediately applied to the surface are visible to the user on the stencil sheet itself.

Abstract: The screen printing process together with halftoning techniques for reproducing continuous tone color images has given considerable moire problems. Interferences between the halftoning technique and the screens, and the subsequent screens may be alleviated by appropriate orientation of the screens with respect to each other. Preferentially a frequency modulation halftoning technique is used for halftoning the color components.

Abstract: A silk screen printing apparatus of modular design which can be easily assembled and disassembled and easily transported on an ordinary hand truck in which there can be repetitive multi-color patterns printed on a plurality of like articles with precise registration of the silk screens and in which there can be an additional heating and drying mechanism as a separate, compatible, modular unit such as to permit in-line printing of fabric such as T-shirts and the drying of the printed T-shirts.

Abstract: A screen printing machine having a rotor, a stator, a device for moving the rotor and stator into juxtaposition, and an annular track and track followers for guiding the rotor in vertical and radial directions.

Abstract: A multi-colored silk screen printing machine has an improved electric resistance heating station to cure silk screen printed ink on a substrate such as a textile. A control system has a proximity switch that detects the presence of a pallet within the heat curing station and starts supplying electrical power to a bank of electric resistance heaters automatically only when a pallet is present. An infrared temperature sensor is used to measure the ink temperature when the bank of electric resistance heaters is heating the printed ink on the textile. The infrared sensor provides a signal to a control system that interrupts power to the bank of electric resistance heaters when the signal exceeds a preselected maximum ink temperature value. A timer can also be used to override the infrared temperature sensor. A sheltered passageway and a low level air flow therethrough protect the face or lens of the infrared sensor from gases, smoke or other types of contamination.

Abstract: A screen printing machine has a drive mechanism for moving printing platens along an endless horizontal path through successive printing stations and a printing screen carried by a printing head above the endless path at each printing station. A platen alignment mechanism at each printing station has locating members movable vertically into and out of engagement with freely rotatable rollers on the platen supports. A screen positioning mechanism at each printing station has screen holders engageable with opposite sides of screens, and the screen holders each comprise a screen support mounted for pivotation to and fro between a position beneath one of the screens. A lifting system at each printing station has supports positioned to support opposite ends of one of the printing heads and a support drive mechanism operable to simultaneously raise the supports.

Abstract: A turret style printing machine (10) having a plurality of radial arms (30,70,170) incorporates a plurality of hinge assemblies (35,75,175) for permitting the arms to be moved between a first, extended position for operation of the machine and a second, folded position for storing or transporting the machine (10).

Abstract: The disclosed printing apparatus is includes an ink-permeable cylindrical printing drum which is rotated about an axis of rotation thereof with a heat-sensitive stencil sheet wound around the circumferential surface thereof; a liquid ejector which ejects a photothermal conversion material contained in a liquid to the heat-sensitive stencil sheet in accordance with image information, so that the photothermal conversion material is transferred to the stencil sheet as a reproduction of the image; a light which radiates a visible or infrared ray to the stencil sheet to which the photothermal conversion material has been transferred, such that the stencil sheet is perforated by heat emitted by the photothermal conversion material; and a presser which presses at least either the printing drum or printing sheet that is being moved in synchrony with the rotation of the printing drum, bringing the drum and printing sheet into close contact with each other, such that the stencil printing ink that is fed into the printi

Abstract: Printing screens are registered using a photosensitive position locating sensor which is affixed to a pallet and aligned with the image of a register mark on the first of a series of printing screens. The location of the image is stored and signalled in a display device. The pallet is then roughly aligned with a second and subsequent screens of the series. The subsequent screens are each moved until the image of its register mark is superimposed upon the stored image. The signal output from the sensor is applied to a microprocessor which controls the display device.

Abstract: A turret style printing machine (10) includes a first tier (16) of pallet supporting members (14), a second tier (20) of printing head supporting members (18) and a third tier (24) of printing head supporting members (22). One can thus selectively move either a second tier member (18) or a third tier member (22) into alignment and registration with a first tier member (14). A uniform registration is further provided ensuring the second third tier supporting members consistently align with the first tier supporting members (14). This expansion increasing the number of stations is accomplished without necessarily increasing the required floor space or system diameter.

Abstract: A device to align images for a printing press control system comprising, a device for capturing a reference image containing one or more image planes from a reference copy, a device for converting the reference image into a monochrome reference image, a device for capturing a production image containing one or more image planes from a production copy, a device for converting the production image into a monochrome production image, a device for defining at least one object model in the monochrome reference image, a device for identifying the position of at least one of the object models in the production image, a device for defining a transfer function which maps the position of the models in said monochrome production image to the position of the models in said monochrome reference image, and a device for applying the transfer function to each of the image planes of the production image, resulting in its alignment to the reference image.

Abstract: The several screen frames of a multistation screen printing machine, such as a carousel screen printer, having multiple work supports movable to the printer stations in succession to effect successive printing of screen images on work pieces fixed to the supports are precisely registered with the work supports by providing each frame with two and preferably three registration points precisely located relative to the screen image on the frame, providing a selected work support with the same number of registration points precisely located relative to the position of a work piece on the selected support, effecting movement of the selected work support to the print stations in succession, adjusting the corresponding screen frame to directly align its registration points with the registration points on the selected work support, and securing the frame in fixed position relative to its respective print station while the frame and work support are firmly held in fixed position by registration pins extending between

Abstract: Printing screens are registered using a photosensitive position locating sensor which is affixed to a pallet and aligned with the image of a register mark on the first of a series of printing screens. The location of the image is stored and signalled in a display device. The pallet is then roughly aligned with a second and subsequent screens of the series. The subsequent screens are each moved until the display image of its register mark is superimposed upon the stored image. The signal output from the sensor is applied to a microprocessor which controls the display device.

Abstract: An apparatus for printing materials, particularly textile materials, ceramics, paper or the like, has a housing and a drive apparatus, with several printing units, which are respectively associated with a pallet arranged on a pallet carrier and with a rotary drive which receives the pallets and which transfers the pallets into a succeeding processing station, and with a plate which carries the printing units and which can be moved up and down with a lifting apparatus, wherein the rotary drive is constructed as an indexing table with a rotary plate and can be indexed electromechanically.

Abstract: A method for screen printing is provided where multiple screen frames used to facilitate multiple images are carried in fixed registration for an entire screen printing process. The method includes positioning and registering at least two screen frames in fixed registration inside a master frame with the screen frames disposed adjacent to one another and lying in a common plane with the master frame. The steps of coating the screens with emulsion, drying the coated screens, and producing an image on the screens are provided. The master frame is loaded in a printing press and the screens are inked. Printing occurs by repeatably positioning an object in adjacency to each screen for transferring ink through each screen onto the object to produce multiple images on the object where the screens are maintained in fixed registration relative to one another.

Abstract: A screen printing press is provided for printing on a web having defined, successive areas and indicia provided in predetermined positions relative to each of the defined areas. The press includes a base defining a work station, a screen supported on the base for movement between a printing position overlying the work station and an interrupted position, and a web handling assembly for advancing the web along a path of travel to successively feed the defined areas of the web toward the work station. A registration system successively positions the defined areas of the web in a desired predetermined relationship to the screen as successive defined areas are brought into a position to be printed. The registration system includes longitudinal, lateral and angular shifting mechanisms for adjusting the longitudinal, lateral and angular alignment between the screen and the web.

Abstract: An method and apparatus for forming adhesive and solder pads on a printed circuit board to surface mount electrical components to the board. In accordance with an embodiment of the invention, a solder paste is deposited onto the printed circuit board through a first stencil that has a plurality of first openings. The solder paste forms a plurality of solder pads on the board. A second stencil is then positioned on the printed circuit board. The second stencil has a plurality of second openings, and a recess in its bottom face configured to receive the plurality of solder pads. After the second stencil is positioned on the printed circuit board so that the solder pads are received in the recess on the bottom face of the second stencil, an adhesive material is deposited onto the board through the second openings of the second stencil to form a plurality of adhesive pads on the board.

Abstract: A simulated Jacquard fabric and method of fabrication. A flocked fabric is screen printed with specially engraved screens for each color of the design. Thereafter a blotch screen is used to overprint with dyes at a certain pressure that causes the formation of simulated binding or fine lines to simulate a Jacquard fabric.

Abstract: A sequencing system for a printing press, the printing press having a plurality of print stations, each of the print stations for printing a respective portion of a design on an item with ink, the printing press also having a curing station for curing the printed ink, the sequencing system comprising a controller having random access memory for selecting one of the print stations, for selecting one of the print stations, for indexing the item to the selected print station, for determining whether the item is present at the selected print station, for actuating the selected print station to print the respective portion of the design on the item, determining completion of the actuation, for selecting one of the curing stations, for indexing the item to the selected curing station, for determining whether the item is present at the selected curing station, for actuating the selected curing station, and for determining completion of the curing operation.

Abstract: An image printing apparatus (10) comprises a frame (11) to be fixed by suction cups (15) upon a surface (25) to receive an image. The frame (11) defines a space to receive a screen print frame (16). The position of screen print frame (16) may be adjusted by manipulation of the adjustable positioning cams (12, 13). Once accurately positioned, positioning cams (12, 13) are fixed by rotation of tightening knobs (18). An image of a selected color may then be printed upon the surface (25) using screen print frame (16). For overlaid prints in other colors, frame (16) may be removed, leaving at least some of the adjustable positioning cams (12, 13) in place such that a further screen print frame (16) of identical size and shape may be positioned accurately with respect to the previously printed image by contact with the positioning cams. Images of multiple colors may be printed in this manner.

Abstract: A recording apparatus is formed of a drum which is rotationally driven around a central axis of itself with a stencil sheet having a solvent-soluble resin layer wrapped around an outer circumferential surface of the drum, an ink supplying device disposed to the inside of the drum and supplying ink to an inner circumferential surface of the drum, and a solvent supplying device for selectively supplying a solvent containing a colorant to the stencil sheet, thereby conducting perforating the stencil sheet and selectively supplying the solvent to the printing paper thereby conducting recording.

Abstract: A method of molding a design in low relief in an area of printing ink with a puffing agent placed on fabric which comprises applying a molding die with a reverse impression of the design to be molded on the ink under heat and pressure for a sufficient time to activate the puffing agent to produce a molded design in the ink with a minimum change to the physical configuration of the underlying fabric. Heat and pressure can also be applied through a transfer medium to the area surrounding where the design in low relief is to be formed to enhance the feel or hand of the fabric. This method is especially useful for molding a design on cotton and cotton blend T-shirts and sweatshirts, hats and denim jackets.

Abstract: A screen printing machine has a bearing supporting a first arm structure for rotation about a vertical axis, the first arm structure comprising first arms equiangularly distributed about the vertical axis and extending radially outwardly of the vertical axis. The first arms each carry, at a free outer end thereof, a printing screen support platen. A second arm structure has second arms equiangularly distributed about the vertical axis and extending radially outwardly of the vertical axis, the second arms each carrying, at a free outer end thereof, a squeegee mechanism and a printing screen support for holding printing screen below the squeegee mechanism.