Abstract: A screen printing apparatus comprising a plurality of print stations arranged in a circle and an equal plurality of platens carrying objects to be printed by the print stations. Objects to be printed are placed on platens at a loading/unloading one of the stations and the platens are indexed around the circle of print stations for printing. A control unit controls the printing at the print stations and selectively inhibits printing at individual ones of the print stations. During start up, the control unit activates print stations, one at a time, in synchronism with the indexing of the platens. A skip mode is available in which printing at a given platen is inhibited by the control unit at each print station, when the given platen is at that print station. The control unit also successively inhibits print stations, one at a time, in synchronism with platen indexing to provide a controlled stop of the apparatus.

Abstract: A control for the electrical curing elements on screen printing apparatus which applies full power to the elements during a heat-up period, and upon attaining a preselected temperature the control switches to a selected lower percentage of full power which continues as long as the apparatus continues to index through its printing cycles.

Abstract: Disclosed is a pallet aligning system which allows a pallet to be mounted to a pallet support arm in a desired orientation and lateral spacing with respect to the support arm and thereafter be removed and remounted to the support arm in the previously defined orientation and lateral spacing, thereby precluding the need to reposition the pallet upon each subsequent reattachment thereof to a pallet support arm. This pallet alignment system is particularly useful when combined with a screen alignment system to re-establish registration of the screens as well as the pallets used therewith. Lateral restraining members are mounted to the underside of the pallet for selective laterally movement. After the pallet has been oriented and positioned as desired, the lateral restraining members are moved into abutment against opposite lateral sides of the pallet support arm and secured in their respective positions thereat to maintain the set orientation and location of the pallet.

Abstract: In a screen printing cylinder press, the combination comprises:a cylinder having a gripper thereon to grip a sheet,a screen printer including a movable screen printing carriage for applying ink to the sheet on the cylinder;a lever connected to the cylinder and screen printing carriage to move the same through a stroke of given length;a cam having a predetermined profiled cam surface and a cam follower for following the cam surface and connected to the lever to actuate the lever to rotate the cylinder and to reciprocate the screen printing carriage; andadjustable stroke device in said lever for adjusting the stroke of the lever from a given length of stroke, thereby changing the length amount of rotation of the cylinder and the travel of the screen printing carriage.

Abstract: A UV curing apparatus includes a single UV lamp providing a source of UV energy for irradiating ink on a substrate being conveyed through a UV curing station. Substantial reductions in the amount of energy absorbed by the substrate and substantial increases in conveying speeds may be obtained by use of a reflector means which preheats the ink to raise its temperature and then applies UV to cure the previously heated ink. The preferred reflector means has an upstream preheating section of a parabolic shape for providing IR radiation to preheat the ink and a second downstream section of elliptical shape to provide maximum UV radiation of the previously heated ink.

Abstract: A screen printing press carriage is reciprocated by an adjustable stroke lever connected through a cam follower to a cam profiled to cause the carriage to accelerate to its maximum velocity in each direction of travel in substantially less than fifty percent of the travel time in that direction and decelerating over more than fifty percent of the time in each direction.

Abstract: A multi-color printing apparatus for screen printing workpieces in diverse colors. The apparatus has a plurality of printing units, each located at a work station, and spaced about a central support. A number of radially extending support arms cantilevered from a rotatable central support carry the workpieces between printing stations. After being indexed to its approximate final position at a particular work station, the support arms engage a brake pad to absorb rotational energy and to control motion of the support arm during a final, precise alignment step wherein a fork member is advanced toward a roller mounted on the support arm to precisely align and lock the support arm during the screen printing operation. Also disclosed is a collar for rotatably mounting the central support at its bottom end. The collar has two portions, one mounted to the central support and the other mounted to a desired location in the printing apparatus.

Abstract: A printing press having novel sheet transport mechanisms which facilitate precise operation at high speeds. In the preferred embodiment, the press includes a printing bed which pivots forward and downward on parallel links to remove sheets of stock from forwardly opening grippers. Also in the preferred embodiment, novel mechanisms for opening and closing the grippers are provided, including a mechanism for closing the grippers which is inoperable until the grippers are in the proper position to grip the leading edge of a sheet of stock.

Abstract: A method and apparatus for automatically screen printing on objects includes a first transfer mechanism having suction cups for swinging the objects from a supply station at which are located a plurality of the objects to a preregistering station at which is a preregistering device which rotates the objects into a predetermined orientation closely positioned to a reference position to which the object is printed. From the preregistering station, the objects are swung by a second oscillating transfer means to a third oscillatory transfer means which swings the preregistered objects to the printing station. Preferably, the objects are swung into a holding station wherein the objects are held between transfer movements by the respective second and third transfer means.

Abstract: A printing cylinder composed of extruded equally curved cylindric sections joined at the axial edges thereof, one of said sections having a channel recess to provide for a stock gripper assembly, the other sections having axial channels in the outer periphery closed at both ends by end members, with one end member providing a means of communication between groups of these axial channels for evacuation air flow, these sections and end members being surrounded by a perforate cylindrical jacket covering said channels, and journal support shafts on the ends.

Abstract: A squeegee assembly is provided with selectively adjustable stiffness for the squeegee blade to control the deflection of the squeegee blade and thereby the position of the leading edge of the blade when it is under pressure and forcing ink through a screen printing fabric. The preferred adjustment is achieved by a vertically movable clamp having front and rear plates engaging the front and rear faces of the squeegee blade. The clamp is moved up or down the squeegee blade to adjust the stiffness of the blade by moving the plates vertically. Preferably, the plates are at a fixed spacing with a lower end on the rear plate located below the lower end of the front plate. Fasteners clamp the plates to an upper holder and clamp the lower ends of the plates against the squeegee blade.

Abstract: Disclosed is an apparatus for curing ink on the exterior surface of an article preferably with ultraviolet radiation. A conveyor transports the article along an enclosed path within a housing having a wrap-around reflector which provides indirect stray light about the 360.degree. circumference of the article. The interior reflective surface within the housing is preferably dimpled to cause the light to scatter in every direction and to provide indirect substantial uniform light intensity about the curcumference and the top of the article, i.e. uniform and indirect radiation over substantially the entire exposed surface of the article, without requiring rotation or other manipulation of the article. The preferred wrap-around reflector includes reflective specular surfaces on the front and rear walls of the housing as well as the corners of the housing where these walls join the side and top walls of the housing.

Abstract: A master frame assembly for use in a screen printing press carries an upper seal means to seal directly to a screen printing frame to provide an enclosed sealed chamber within the screen frame to contain solvents associated with the ink within the sealed chamber. The preferred upper seal means includes a traveling cover sheet which is pressed directly into sealing engagement with the underlying screen frame about all four sides of the screen frame. Mounted on the master frame are side seal bars for pressing the traveling marginal edges of the sheet against the underlying sides of the screen frame. These side seal bars are adjustably and movably mounted on the master frame so that they may press the traveling cover sheet against the sides of each of several different widths of screen frames.

Abstract: A screen printing apparatus having a rotatable turret with a plurality of work supports is indexed by a curved geneva mechanism to each of a plurality of index positions. The curved geneva mechanism includes a plurality of curved slots having surfaces engaged by the driver with the curved slots designed to minimize the maximum amount of inertia and to maximize the available time for deceleration of the turret to provide a smoother and slower stopping of the turret and registration without banging and jarring of the apparatus. The preferred curved slots have a modified sine wave characteristic to provide slower changes in velocity during the stopping. The amount of inertia change during the indexing motion is analyzed and the curved slots are generated to eliminate abrupt changes in inertia that would result in a rough movement.

Abstract: A master frame assembly for use in a screen printing press carries an upper seal means to seal directly to a screen printing frame to provide an enclosed sealed chamber within the screen frame to contain solvents associated with the ink within the sealed chamber. The preferred upper seal means includes a traveling cover sheet which is pressed directly into sealing engagement with the underlying screen frame about all four sides of the screen frame. Mounted on the master frame are side seal bars for pressing the traveling marginal edges of the sheet against the underlying sides of the screen frame. These side seal bars are adjustably and movably mounted on the master frame so that they may press the traveling cover sheet against the sides of each of several different widths of screen frames.

Abstract: A method and apparatus for automatically screen printing on objects includes a first transfer mechanism having suction cups for swinging the objects from a supply station at which is a preregistering device which rotates the objects into a predetermined orientation closely positioned to reference position to which the object is printed. From the preregistering station, the objects are swung by a second oscillating transfer means to a third oscillatory transfer means which swings the preregistered objects to the printing station. At the printing station, the objects are rotated relative to a printing screen by a rotating chuck device. After printing, grippers are swung into the printing station to remove the printed object and to convey the printed object to discharge station at which is located a discharge conveyor of UV curing apparatus.

Abstract: A manually operated silk screen printing apparatus having a printing bed and a chase overlying the printing bed for removably mounting a screen in alignment with the overlying printing bed. Preferably, a single ball-shaped handle or joystick is mounted on the top of the squeegee carriage for pushing or pulling to slide a squeegee carriage mounted on a lever arm over the center of the screen. The carriage travels on a three-point bearing arrangement with a guide or track surface on the lever arm. Flipping of the handle through an overcenter position reverses the squeegee and the carriage for the respective flood and print strokes. More specifically, the lever arm includes a generally horizontal guide track overlying the chase and extending approximately the length of the screen. The guide track is centered with respect to the chase and guides the carriage.

Abstract: An apparatus for the ultraviolet irradiating printed ink on sheet at a UV curing station is provided with a cooling station immediately downstream of the UV curing station. Air knives at the cooling station increase the air velocity and cause a turbulent air flow across the sheet to cool the same while a suction device beneath an air pervious conveyer for the sheet holds the sheet against fluttering at the curing station and at the cooling station.