Pallet alignment assembly

In a screen printing press, the combination comprising:

• a plurality of screen printing heads for printing on a workpiece;
• located means on the printing heads;
• screen printing frames having a screen with an image thereon for precise registration with images printed with other screens;
• locator means on each screen printing frame for cooperating with its associated locator means on its associated printing head to locate the screen images in a registered position for printing, the screen frame locator means restoring the screen frames in their respective registered positions upon each removal and subsequent reattachment of the screen frames to their respective printing heads;
• a plurality of pallet support arms moveable into registration with each of the printing heads;
• pallets for supporting a workpiece during printing thereon, removably mountable to respective support arms;
• and
• alignment means on the pallets for mounting the pallets on respective support arms in a predetermined orientation and spacing corresponding to said registered position of the screen frames, the alignment means restoring the pallets to their predetermined orientation and position on the support arm, in accurate registration with the registered position of the screen frames, upon each removal and subsequent reattachment of the pallets to their respective support arms, to accurately locate the print on the workpiece following reattachment of the pallets and screen frames to the printing press;
• and
• the alignment means on the pallets comprising a plurality of eccentrics mounted for turning into engagement with their support arms and fasteners to fasten the eccentrics in their engaged positions against opposite sides of their respective support arms.

A method for aligning a plurality of printing screens and a plurality of workpiece supporting pallets on a screen printing press in relation to one another to precisely register printed screen images with one another and accurately locate the printed images on the workpiece, the method comprising:

• mounting the plurality of printing screens, having an image thereon, with registration locating means on print heads of the printing press in relation to one another for printing the images of the screens in precise registration with one another;
• and
• mounting the plurality of workpiece supporting pallets to respective pallet supports of the printing press to align the pallets in an orientation and position corresponding to the registered position of the printing screens to accurately locate the print on the workpiece in a desired orientation and position;
• marking the pallets with indicia to identify the pallets with the pallet supports upon which they were aligned;
• marking the printing screens with indicia to identify the printing screens with the print heads in which they were mounted;
• removing the pallets from the pallet supports and removing the printing screens from the printing heads;
• securing alignment means on each of the pallets in position abutting the respective pallet supports;
• and
• reattaching the printing screens and the pallets to their respective marked locations with the locator means on the printing screens and printing heads re-registering the printing screens and with the alignment means on the pallets re-aligning each pallet in its previously registered position on its support.

In a screen printing press, a pallet assembly for detachably mounting to a pallet support arm, having locating surfaces thereon and on a screen printing press, in a precisely aligned orientation and predetermined position on the pallet support arm, the pallet assembly comprising:

• a base having a lower surface for resting on the pallet arm to be supported thereby during printing,
• first positioning locator means on the underside of the pallet base movable to a first positioning location to engage locating surfaces on one side of the pallet support arm,
• second positioning locator means on the underside of the pallet base spaced from the first positioning locator means, and adjustably movable relative to the base into position to engage locating surfaces on another side of the pallet support arm after the pallet has been precisely aligned,
• locking means operable to lock the second positioning locating means in its respective adjusted position after the pallet has been aligned, and
• releasable securing means operable in a first position to secure the pallet to the support arm with the second positioning locator means locked in engagement with the locating surfaces on the pallet support arm;
• the releasable securing means being movable to a release position to allow removal of the pallet from the support arm and return of the pallet with the first and second positioning locator means remaining in their previous positions to restore the pallet to its previously-aligned orientation and predetermined position on the support arm prior to re-securing the pallet by the releasable securing means.

A pallet assembly, comprising:

• a base having a lower surface for resting on the pallet arm to be supported thereby during printing,
• first positioning locator means on the underside of the pallet base movable to a first positioning location to engage locating surfaces on one side of the pallet support arm,
• second positioning locator means on the underside of the pallet base spaced from the first positioning locator means, and adjustably movable relative to the base into position to engage locating surfaces on another side of the pallet support arm after the pallet has been precisely aligned,
• locking means operable to lock the second positioning locating means in its respective adjusted position after the pallet has been aligned, and
• releasable securing means operable in a first position to secure the pallet to the support arm with the second positioning locator means locked in engagement with the locating surfaces on the pallet support arm;
• the releasable securing means being movable to a release position to allow removal of the pallet from the support arm and return of the pallet with the first and second positioning locator means remaining in their previous positions to restore the pallet to its previously-aligned orientation and predetermined position on the support arm prior to re-securing the pallet by the releasable securing means.

A method of locating a removable pallet on a pallet supporting arm of a rotatable printing press having a plurality of screen printing heads and a plurality of pallet support arms for carrying a pallet to support a workpiece while being printed, said method comprising the steps of:

• rotating a pallet arm beneath a screen printing head and shifting a pallet on the arm into a registered position beneath the screen and printing an image thereon;
• shifting the pallet on the support arm to position the pallet precisely relative to the printing screen;
• providing eccentrics on the pallet for cooperating with locating surfaces on the support arms;
• turning the eccentrics to locating positions in abutment with the locating surfaces on the arm, and securing the eccentrics in the locating positions while against the locating surfaces;
• fastening the pallet to the pallet arm in the locating position;
• printing with the pallet in its registered position;
• removing the pallet for replacement by a second pallet;
• and
• replacing the second pallet with the first pallet leaving the eccentrics in their previously-adjusted positions and abutting the eccentrics against the locating surfaces on the arm to re-establish the same previous registration for the pallet.