Patent Publication Number: US-2009217830-A1

Title: Screen printer print carriage

Description:
FIELD OF THE INVENTION 
     This invention relates to improvements in the print carriages of carousel screen printing machines 
     BACKGROUND TO THE INVENTION  
     Carousel Screen printing machines are used for screen printing of garments and utilise a plurality of fixed print heads beneath which are positioned a plurality of garment support pallets which are moveable from one print head to the next. Each print head has a carriage mounted for reciprocal movement to move the flood bar and squeegee bars over the screen. 
     The flood bar and squeegee blades forming the print head in screen printing machines are mounted on a moving carriage with the flood bar down in the flood stroke and the squeegee down in the print stroke. The carriage is supported at both ends in a print frame and moves back and forth along the print frame. U.S. Pat. No. 5,189,950 discloses a centrally mounted print arm supporting a central portion of the carriage for reciprocal movement along the print arm. The carriage is pneumatically driven along the arm. An alternative to pneumatic drives is electric motor driven drive belts. 
     Conventionally the squeegee and flood bar on the print carriage are bolted in place and are difficult to remove. They are usually attached to the carriage from the top edge of the squeegee or flood bar. A typical arrangement is shown in U.S. Pat. No. 4,939,991. 
     U.S. Pat. No. 5,165,339 discloses a detachable scraper for a flood bar in which the top of the scraper blade is held in the flood bar holder. 
     U.S. Pat. No. 5,722,321 discloses a detachable squeegee blade which again is suspended from the top edge. 
     As the design of the rotary screen printing machines evolve ease of operation and reduction of fabrication costs are of increasing importance. Another desirable attribute is the ease with which screens and flood bar assemblies can be serviced and replaced. 
     It is an object of this invention to provide a squeegee and flood bar that is convenient to install adjust and remove, with minimum affect on the height and length of print stroke. 
     BRIEF DESCRIPTION OF THE INVENTION 
     To this end the present invention provides a squeegee or flood bar for the print carriage of a screen printing machine which consists of a mounting bracket and blade portion in which the bracket portion is adapted for quick attachment and detachment to the print carriage and the bracket is attached to the blade portion on one side of the blade portion. 
     The attachment means is preferably a toggle clamp on the carrier bar for the squeegee and flood bar. By simply releasing the toggle clamp the bracket and blade holder can be quickly removed and replaced. 
     The bracket attaches to one face of the blade near the upper edge and this offset position means that a change in the angle of inclination of the blade does not result in a large change in position of the bottom edge of the blade. 
    
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
       Preferred embodiments of the invention will be described with reference to the drawings in which: 
         FIG. 1  is a view of a detachable squeegee blade according to an embodiment of this invention; 
         FIG. 2  is an exploded view of the blade of  FIG. 1 . 
     
    
    
     The flood bar or squeegee blade consists of the blade portion  11  and the blade holder frames  12  and  13  which are secured together with screws  14 . Attached to frame  12  are the two pivot mounting blocks  16  secured by screws  17  to the frame  12 . Mounting brackets  18  are secured to the mounting blocks  16  by pivot screw fasteners  21  at holes  19 . The brackets  18  are L shaped and include a mounting slot  20  in the horizontal arm. 
     The squeegee and floodbar mounting bar  25  carries two toggle clamps  26  having shafts  27  that pass through holes in the bar  25  and carry the brass bushing  30 . The end of shaft  27  carries the bracket  31  secured by adjustor nut  29 . The spring  28  located about the shaft  27  provides the separating and leveling force between the mounting bar  25  and bracket  31 , to allow easy installation of bracket  18 . 
     The angle of inclination of the blade  11  can be adjusted by changing the relative angle between bracket  18  and the mounting block  16 . The locknut  29  has a retaining washer to adjust the clamping force. 
     To attach the squeegee to the carrier bar  25  the slots  20  of the brackets  18  are located about the bushes  30  and the toggle clamped in place. The toggles can be turned so that the handles are tucked away from interfering in the operation of the carriage. 
     From the above it can be seen that this invention provides a unique squeegee or flood bar design that provides flexibility and ease in changing machine configurations. 
     Those skilled in the art will appreciate that the teachings of this invention may be implemented in other embodiments without departing from the core concepts of the invention.