Abstract: A screen printing apparatus has simultaneously movable multiple print heads made movable by a single fluid cylinder. The apparatus also has multiple printing platens, and structure for indexing and simultaneously registering the multiple platens into printing position, as well as combined flood bar/squeegee ink applicators which are capable of simultaneously shifting of operational positions, and provide a high quality printed image on the goods printed thereby.

Abstract: A take-off device for gripping and releasing an article has a gripper heat capable of imparting a downward force to an article gripped thereof. The gripper head has a lower jaw and an upper jaw, the lower jaw being capable of moving linearly with respect to the longitudinal axis of the take-off device. The upper jaw is capable of pivotal movement below the line of linear movement of the lower jaw after the lower jaw has moved linearly to release the article gripped by the gripper head, whereby a downward force to an article gripped and released by the take-off device may be imparted.

Abstract: Screen printing apparatus having an inner stationary column having a vertical axis and an outer rotatable cylinder encircling the column and rotatable about the vertical axis. A rotatable turntable is mounted on the rotatable cylinder for movement between successive screen printing stations. The turntable mounts plural work supports having vacuum beds to retain workpieces. A vacuum ring is connected to a stationary vacuum means and has a slidable sealed contacting surface with the turntable to transfer vacuum to a plurality of conduits extending to each work support.

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 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 multi-color printing apparatus for automatically screen printing workpieces in diverse colors. The apparatus has a plurality of printing units spaced about a central support. A number of radially extending support arms cantilevered from the central support carry the workpiece at their free end for movement between printing units. After being indexed to its approximate final position at a particular station, a brake is engaged to prevent rotation of the support arm and a lock engages the support arm bring the arm into a registered position for the duration of the printing operation, after which the brake and locking bar are disengaged, allowing the support arm to rotate to another printing unit.

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 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.

Abstract: An automatic peel control mechanism for use in a screen printing press employs a cam-driven mechanical linkage to raise the front end of the screen frame at a controlled rate to a predetermined height above the printing bed in timed relation to the motion of the carriage which transports the squeegee. The linkage includes a pair of elongated reciprocating bars which extend the length of the printing head and are connected to lifters at their forward ends to lift the front end of the printing screen. The cam is rotatably mounted upon the carriage drive shaft. The rotation of the cam is controlled by a roller chain assembly which maintains a timed relationship between the cam and the drive shaft. The initial off contact dimension and peel rate may be readily adjusted by varying the initial position and the rate of travel of the elongated bars.

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: A screen printing frame is formed with hollow extruded metal frame members joined at their ends by extruded metal interfitting connectors which are retained within the ends of their associated frame members by frictional engagement supplemented by a bonding agent. The force required to establish the frictional engagement is maintained in the preferred embodiment by elastic flexure of a bowed side wall on each connector arm. The structural members may have prefinished surfaces such as anodized surfaces and are joined together without welding as would mar such surfaces during the welding operation. The amount of metal used for the extrusions has been minimized for cost reduction and to obtain a lightweight structure.Grooves on the interfacing surfaces of the connector arms and the frame members cooperate to form an interstitial lattice which receives a bonding agent. Miter joints at the corners of the structure are sealed by corner webs on the connectors in combination with a bonding agent.