Printing Machine Safety System

Abstract

A screen printing safety system is provided. The system includes a screen printing machine, and a plurality of zones in the vicinity of the screen printing machine. Each of the zones includes at least one sensor for sensing encroachment past a predetermined point. The sensors are adapted to stop operation of the screen printing machine when encroachment is sensed in at least one of the plurality of zones.

1 . A screen printing safety system comprising:
 a screen printing machine;   a plurality of zones in the vicinity of the screen printing machine, each of the zones including at least one sensor for sensing encroachment past a predetermined point;   the sensors adapted to stop operation of the screen printing machine when encroachment is sensed in at least one of the plurality of zones.   
     
     
         2 . The screen printing safety system of  claim 1  wherein the plurality of zones includes first, second and third zones. 
     
     
         3 . The screen printing safety system of  claim 2  wherein the first zone includes a physical barrier. 
     
     
         4 . The screen printing safety system of  claim 3  wherein the physical barrier includes a gate. 
     
     
         5 . The screen printing safety system of  claim 4  wherein the gate is approximately waist-high. 
     
     
         6 . The screen printing safety system of  claim 2  wherein the second zone sensor includes a light curtain. 
     
     
         7 . The screen printing safety system of  claim 6  wherein the light curtain includes a light emitting component and a light reflecting component. 
     
     
         8 . The screen printing safety system of  claim 2  wherein the second zone is located above the first zone. 
     
     
         9 . The screen printing safety system of  claim 2  wherein the third zone establishes a perimeter around the screen printing machine. 
     
     
         10 . The screen printing safety system of  claim 2  wherein the third zone sensor includes a light curtain. 
     
     
         11 . The screen printing safety system of  claim 10  wherein the light curtain includes a plurality of light emitting components and light reflecting components. 
     
     
         12 . The screen printing safety system of  claim 1  wherein the at least one sensor includes a video comparison system. 
     
     
         13 . The screen printing safety system of  claim 1  wherein the at least one sensor includes a photoelectric eye. 
     
     
         14 . The screen printing safety system of  claim 1  wherein the at least one sensor includes a scanner to scan a designated area for encroachment into a designated area. 
     
     
         15 . The screen printing safety system of  claim 14  wherein the designated area is the first zone. 
     
     
         16 . The screen printing safety system of  claim 14  further including an air curtain, the air curtain directing airborne particles away from the scanner. 
     
     
         17 . The screen printing safety system of  claim 14  wherein the designated area includes a warning field and a protective field. 
     
     
         18 . The screen printing safety system of  claim 14  wherein there is a time delay between sensing encroachment into the designated area and stopping operation of the printing machine. 
     
     
         19 . The screen printing safety system of  claim 1  wherein the operation of the screen printing machine restarts once the encroachment is no longer sensed. 
     
     
         20 . A screen printing safety system having two areas of protection from encroachment comprising:
 a screen printing machine having a loading area and a printing area;   a first entryway to the loading area from outside the loading area having a first vertical dimension from the floor to a top being sufficient to accommodate a human operator;   a segmented barrier to the first entryway enclosing a first area of protection, the segmented barrier comprising:
 a gate moveable from an open position to provide access to a first zone to a closed position to form a physical barrier to entry into the first zone, the gate adapted to stop operation of the machine upon movement of the gate; and 
 a first light curtain sensor for detecting encroachment into a second zone, the first zone and the second zone being disposed in a common vertical plane spanning a portion of the first entryway, the first zone extending approximately to the first height and the second zone extending from a point upward therefrom to the top; 
   a first fence at one end of the gate to form a barrier to entry to the first area of protection;   a second entryway to the printing area;   a second light curtain sensor surrounding the second entryway to define a second area of protection; and   the first light curtain sensor and the second light curtain sensor being adapted to stop operation of the screen printing machine when encroachment is sensed.   
     
     
         21 . The screen printing safety system of  claim 20  further comprising a second fence at an opposed end of the gate to form a barrier to entry into the first area of protection. 
     
     
         22 . The screen printing system of  claim 21  wherein the first fence supports a light producing component of the first light curtain and the second fence supports a light receiving component of the first light curtain.