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: 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 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: 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: 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.

Abstract: An apparatus for curing ink screen print on articles, particularly large articles such as pails or barrels, includes a rotatable turntable having a plurality of spin table compartments each of which is to receive a pail and carry the same in a circular path past a radiation source covered by a housing at a curing station. Each article is spun as it reaches the curing station to assure complete irradiation about the circumference of each article. The housing is provided with a large opening to facilitate loading of articles onto the spin tables and removal of articles with cured ink from the spin tables. An ejector mechanism is mounted on the apparatus to automatically eject cured articles from the turntable to reduce the labor needed to operate the apparatus. The preferred ejecter mechanism includes a fluid cylinder having a pusher mounted centrally of the turntable, and operable to extend into a compartment to push an article therefrom onto a takeaway conveyor.

Abstract: An apparatus for curing ink screen print on articles, particularly large articles such as pails or barrels, includes a rotatable turntable having a plurality of spin table compartments each of which is to receive a pail and carry the same in a circular path past a radiation source covered by a housing at a curing station. Each article is spun as it reaches the curing station to assure complete irradiation about the circumference of each article. The housing is provided with a large opening to facilitate loading of articles onto the spin tables and removal of articles with cured ink from the spin tables while the turntable continuously rotates.

Abstract: A carriage drive mechanism for a screen printing press includes a stroke adjustment mechanism which enables the length of the printing stroke to be altered quickly and conveniently from the exterior of the press without interrupting operation of the press.The preferred drive mechanism includes a pivoting drive lever joined to a crank link by a movable connector. Longitudinal displacement of the connector on the drive lever alters the length of the stroke of the drive lever, which alters the length of the printing stroke. The preferred means for displacing the connector includes a threaded rod which is disposed within the drive lever and which extends through a threaded bore in the connector so that rotation of the threaded rod about its longitudinal axis imparts longitudinal motion to the connector.

Abstract: An apparatus and method are disclosed for individually transporting large sheets of stock which may have curled ends from a planar support surface such as a printing bed to another location, such as a delivery station. The present invention includes lifting members for positioning a leading end of each sheet at a predetermined elevation prior to engagement by a purality of grippers having upper and lower jaws which grip the end of the sheet to transport it. In the preferred embodiment, the lifting member comprises a plurality of pins mounted in the support surface which are driven upward to raise the leading end of the sheet.

Abstract: In the preparation of screen process stencils a stencil frame is enclosed tightly by a pneumatically operated frame. Once the stencil frame is enclosed the pneumatic tensioning frame is inflated pulling a screen fabric outwardly to stretch the same with a concomitant vertical movement of the frame member and frame supporting portion of the tensioning frame so that the top wall of the frame member is pushed tightly and intimately against the underside of the screen fabric thereby promoting the desired adhesion between the fabric and the frame. This is achieved inexpensively in the present invention by providing a support means which supports the screen tensioning device at a predetermined angle to the horizontal so that with movement of the fabric carrying portion outwardly away from the stencil frame, the frame support portion is being raised and is lifting the side frame member upwardly against the underside of the screen fabric.

Abstract: A curing unit includes an arcuate reflector shield open at the lower end with a curing lamp in the shield and a cooling chamber above the shield. Cooling fluid is directed into the chamber toward the outer surface of the shield and some of this cooling fluid is also directed along the inner surface. Light trap are located adjacent the leading and trailing edges of the unit above an article conveyor belt and a vacuum chamber is located below the belt to draw ozone generated by the unit, as well as hold the article on the belt.

Abstract: A screen printing press including structure and electrical control circuits which permit selection of optimum speeds for the flood and print strokes, and which speeds may differ one from the other.

Abstract: A bottle printer includes a carriage reciprocated along a fixed screen and a squeegee and flood bar carried by the carriage. A bottle support and a nose cone are adjustably supported on the carriage to accommodate bottles of different sizes. A bottle registration mechanism is supported on the carriage and moves with the carriage.