SCREEN PRINTING MACHINES

Abstract

A quick release pallet for a screen printing machine in which the pallet for supporting an item to be screen printed having having a longitudinal axis a top surface for supporting a garment to be printed and an underneath portion for attachment to a pallet arm; a top plate of a porous material; and at least one key hole slot in the underneath portion of said pallet. The pallet arm supports the pallet along its longitudinal axis and has attachment means to cooperate with the underneath portion of the pallet. The attachment means comprises two fastening heads adapted to fit and slide in the slot in the underneath portion of the pallet and the fastening heads are able to be clamped against the slot to fix the pallet to the pallet arm. The advantages are that the pallet has no attachments and can be very quickly positioned and released. Because there are no screw holes in the top surface of the pallet it has a larger print area. The pallet can be modified to a vacuum pallet with a perforated or porous top plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of this invention will now be described with reference to the drawings in which:

FIG. 1 is an exploded view of the pallet arm and pallet of this invention;

FIG. 2 is a side view of the pallet fastened to the pallet arm;

FIG. 3 is an underneath plan view of the lower portion of the pallet of this invention;

FIG. 4 is a detailed side view of a preferred toggle assembly according to the invention.

The pallet 10 is a flat aluminium cast plate of a size matched to the garment to be printed. The pallet has an upper surface 12 and a lower surface 11 to which an attachment plate or underlay 13 is attached by way of screws at points 19 in each corner. Alternatively the underlay 13 may be adhered to the surface 11 of the pallet. The underlay 13 incorporates a first slot 14 commencing in an end edge of the underlay and a second slot 16 located longitudinally in line with slot 14 toward the opposed edge of the underlay 13. Each of slots 14 and 16 include recessed edges 15 and 17. The second slot (16) has an opening 18 at the end closest to slot 14 to allow the bolt head 25 to be introduced into the slot 16.

An alternative pallet arrangement uses a continuous slot formed in the under surface of the pallet, instead of two separate slots. Such a pallet can be formed in one piece by extrusion and avoids the need for machining or assembly of an underlay to the pallet body.

The pallet arm 20 has an upper surface 21 and a side portion 22. Counter sunk bolt heads 24, 25 protrude from the upper surface 21 of the pallet arm 20. On the under sides of the heads 24, 25 are inclined faces which engage the edges 15, 17 of the slots 14, 16 in underlay 13. Associated with the bolt heads 24, 25 are the toggles 26, 27 which act to press the heads 24,25 against the edges 15, 17 to secure the pallet in position.

A preferred toggle assembly is shown in FIG. 4. The lever 27 acts on the shaft 30 to which the head 25 is attached. A compression spring 32 is inserted between the head 25 and a spacer 31 to provide a spring loaded locking arrangement.

To assemble a pallet to a pallet arm the pallet is centered on the pallet arm so that the slots 14 and 16 are on the remote side of the heads 24, 25 and then pulled toward the free end of the pallet arm. To lock the pallet to the arm the toggles 26, 27 are actuated.

From the above description it can be seen that this invention provides

• • 1) a pallet that is simple to manufacture.
  • 2) The pallet is simple to assemble to the pallet arm.
  • 3) The pallet has a larger free surface for printing because there are no screw holes through its top surface
  • 4) The pallet and arm can be made from off the shelf components which reduces the costs of production.

The pallet may be adapted for use with a vacuum line as described in U.S. Pat. Nos. 6,575,091 and 6,789,473.

Those skilled in the art will appreciate that this invention can be implemented in embodiments other than those described without departing from the core teachings of this invention.

Claims

1. In a screen printing machine of the type having a pallet mounted on a pallet arm which is successively brought into registry with a series of printing heads the improvement comprising a) a pallet having a longitudinal axis, a top surface for supporting a garment to be printed and an underneath portion for attachment to a pallet arm;b) a pallet arm to support said pallet along its longitudinal axis and having attachment means to cooperate with the underneath portion of the pallet;c) at least one slot in the underneath portion of said pallet;d) and two fastening heads adapted to fit and slide in said slot in the underneath portion of said pallete) said fastening heads able to be clamped against the slot to fix the pallet to the pallet arm

2. A pallet for supporting an item to be screen printed having a) having a longitudinal axis, a top surface for supporting a garment to be printed and an underneath portion for attachment to a pallet arm;b) at least one slot in the underneath portion of said pallet.

3. A pallet arm as claimed in claim 2 in which there is one continuous slot in the underneath surface of said pallet.

4. A pallet arm as claimed in claim 3 which is formed by extrusion.