Abstract:
A method for washing cored heads of lettuce includes placing such heads in a position with their cored holes facing downwardly toward an upwardly-directed spray of an aqueous solution, directing such a spray into, and washing the holes, then pushing the heads from that position onto a conveyor.

Description:
CROSS-REFERENCE AS TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 09/234,152, filed Jan. 19, 1999, in the United States Patent and Trademark Office (“PTO”), and now issued as U.S. Pat. No. 5,954,067, issued on Sep. 21, 1999. The &#39;152 application is a division of U.S. patent application Ser. No. 09/144,792, filed Sep. 1, 1998, in the PTO. 
    
    
     This invention relates to an apparatus and methods for washing the cored area of a lettuce head. 
     These apparatus, in preferred embodiments, include a perforated platform, preferably a perforated platform, connected to and supporting a tripod, or other lettuce head guide, that fits into the core hole of a cored lettuce head, and orients the lettuce head during washing of the core hole. Preferably, the guide includes three L-shaped vanes that project upwardly from the support platform. 
     In preferred embodiments, a support platform includes supports for a lettuce head holder. This holder has an opening sufficiently large to permit the guide to project through the opening with the holder in a first position over the guide. The opening in the holder includes, near the top of the holder, a recess, preferably of sufficient size and shape to receive and support a cored head of lettuce. In the first position, the core hole of a lettuce head is placed over the guide and into the recess of the holder, with the lettuce head otherwise resting in the recess of the holder. 
     The holder is pivotally connected to two holder supports. The two holder supports are connected to the support platform so that the holder can move upwardly from the first, preferably horizontal position, where the guide projects through the opening in the holder, to a second raised position at a distance of 45° to 75° from the first position. This movement to a second position unseats the cored area of the lettuce head from the guide and propels the lettuce head onto a conveyor that carries the cored, washed lettuce head from the washing apparatus. 
     Below the perforated platform is a housing for a chamber that stores and dispenses aqueous, lettuce head washing solution. Inside this chamber is an inlet valve through which such a solution enters the chamber. This inlet valve is connected to a float mechanism. The inlet valve maintains a predetermined, adjustable level, usually at or near the middle of the chamber. 
     Inside the chamber are a screen and screen housing through which the aqueous solution exits the chamber and flows, via lines and valves, into a pressurizable chamber. At least one valve is a check valve that prevents the aqueous solution from escaping the pressurized chamber, and flowing upstream toward the screen and screen housing. Inside the pressurized chamber is a syphon, preferably of cylindrical shape, with an opening at a distal end near the bottom of the pressurizable chamber. Aqueous solution enters the syphon from this distal end, and flows, under pressure, upwardly toward a nozzle at the proximal end of the syphon. The pressurized chamber also includes an opening for admitting a pressurizing gas such as air into the chamber. In preferred embodiments, the nozzle at the proximal end of the syphon discharges a spray of aqueous solution upwardly into and through the area within the guide, and into and around the cored area of a lettuce head to wash the head efficiently. 
     The washing apparatus also includes pressure driven timers. These timers control the time for aqueous solution to exit the chamber and flow into the pressurizable chamber; start and stop the flow of pressurizing air or other gas into the pressurizable chamber; initiate and sustain the spray from the nozzles into the area with the guide and into the core hole of a cored lettuce head placed on the guide; control the time for ejecting the cored lettuce head; and control the time delay between one wash cycle and another. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows an end elevation view in cross-section of a preferred embodiment of the cored lettuce head washing apparatus of this invention; 
     FIG. 2 is a side elevation view in cross-section of the cored lettuce head washing apparatus shown in FIG. 1; 
     FIG. 3 is a top plan view of the cored lettuce head washing apparatus shown in FIGS. 1 and 2; 
     FIG. 4 is a schematic of a preferred embodiment of an air pressurizing system for the apparatus of FIGS. 1 to  3 ; 
     FIG. 5 shows the apparatus of FIGS. 1 through 4 with a cored lettuce head in place, ready for washing; 
     FIG. 6 shows the apparatus of FIG. 5, with an aqueous liquid washing spray passing upwardly into, and washing, the cored hole of the lettuce head shown in FIG. 5; and 
     FIG. 7 shows the apparatus of FIG. 6 propelling the cored lettuce head, after washing of the core hole as shown in FIG. 6, onto a suitable conveyor (not shown). 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows lettuce head washing apparatus  100 . Apparatus  100  includes perforated platform  101  that supports, and is connected to guide  8 . Guide  8  includes three L-shaped vanes, that project upwardly from platform  101 . 
     Also attached to washing apparatus  100  are supports  102  and  103  for platform  104 . Platform  104  includes opening  105  sufficiently large in diameter to permit guide  8  to project through opening  105  with platform  104  in the horizontal position shown in FIG.  1 . Opening  105  includes, near the top of platform  104 , recess  106 . Recess  106  is of sufficient depth and size to receive and support a cored head of lettuce when the core hole is placed over guide  8  with the balance of the lettuce head resting in recess  106 . 
     Platform  104  connects to supports  102  and  103  with pivots  107  and  108  and is moveable upwardly from the horizontal position shown in FIG. 1 to a second position, as shown in FIG.  8 . Pneumatic piston  109  is connected by rod clevis  110  to platform  104 , and can move platform  104  from the position shown in FIG. 1 to the position shown in FIG.  7 . 
     Below platform  101 , and supporting platform  101 , is chamber  25 . Inside chamber  25  is valve  112  through which such a solution enters chamber  25 . Valve  112  is connected to float mechanism  113 , and opens when float  113  drops to a predetermined, adjustable level, usually at or near the middle of chamber  25 . Chamber  25  also includes screen and screen housing  114 . Aqueous solution in chamber  25  passes through screen housing  114 , line  115 , fitting  116  and check valve  117  into chamber  118 . Chamber  118  includes bottom closure  119 . 
     Inside chamber  118  is syphon  121 . Chamber  118  and syphon  121  receive aqueous solution via line  115 , fitting  116  and check valve  117 . Pressurizing air enters chamber  118  through opening  122  via an air pressurizing line (not shown). As the air pressure increases in chamber  118 , the aqueous solution in chamber  118  moves downwardly in chamber  118  and upwardly through syphon  121 , and nozzle  123 , then sprays upwardly into the area inside guide  8 . 
     FIG. 4 shows a schematic of the air pressure system that operates aqueous wash apparatus  100 . When a user pushes the momentary start button  400 , switch  200  is activated. Switch  200  delivers an air pressure signal on line  201  to timer  202 . Another air pressure signal then passes via line  205  to, and activates valve  206 , and valve  207 . Input Air (line  210 ) passes through check valve  208  and line  209  to chamber  118 . After chamber  118  is pressurized, and the aqueous solution in chamber  118  is sprayed through nozzle  123  into the core hole of a cored lettuce head for a time determined by timer  202 , air supply to chamber  118  ceases. After timer  202  times out, input air pressure is delivered through regulator valve  217  via line  218  to air cylinder  109  to move platform  104 , propelling a cored lettuce head onto a conveyor (not shown). After a predetermined time passes, an air pressure signal from timer  213  passes to reset timer  202  and deactivate air cylinder  109  via line  214 . 
     FIGS. 5,  6  and  7  show the sequence of operations in the washing of a cored lettuce head  300  by apparatus  100 . FIG. 5 shows cored lettuce head  300  placed on guide  8  with core hole  301  atop guide  8 . In FIG. 6, an aqueous solution from chamber  118  is sprayed through nozzle  123  into lettuce core hole  301 . In FIG. 7, platform  104  moves upwardly as the rod clevis  110  connected to piston  109  moves upwardly to deliver lettuce head  300  onto a suitable lettuce head conveyor belt.