Abstract:
Improvements in a spray nozzle with fluid operated orifice cleaning member, these improvements consisting of an additional conduit connecting the lower chamber with the source, distance limiting devices limiting the distance of travel of the diaphragm, and a resilient washer to be compressed upon the downward movement of the diaphragm to minimize dripping.

Description:
SUMMARY 
     In the following specification I will explain three physical problems encountered in the operation of the &#34;Agricultural Spray Nozzle with Fluid Operated Orifice Cleaning Member&#34;, and will solve those physical problems and will claim these solutions as my invention. 
     The afformentioned physical problems and solutions are: 
     1. In my original application (Ser. No. 4,167) U.S. Pat. No. 4,248,381, I relied upon the nozzle orifice as an escape for the fluid present in the lower chamber when fluid was introduced into the upper chamber. If this nozzle orifice is blocked, movement of the diaphragm-punch assembly is sluggish or non-existant. In order to overcome this problem a second exhaust conduit is added. 
     2. In use, the only limit of movement of the diaphragm center is the physical strength of the material comprising the diaphragm. In order to avoid damage to the diaphragm, I have introduced mechanical stops. 
     3. In my original claims, I claimed that my invention minimized dripping. In order to be able to claim that this device stops dripping, I have installed a flexible, pliable, sealing device. 
    
    
     BRIEF EXPLANATION OF THE DRAWINGS 
     FIG. 1 shows the &#34;Agricultural Spray Nozzle with Fluid Operated Cleaning Member&#34; in the spraying position and includes the new parts. 
     FIG. 2 shows the &#34;Agricultural Spray Nozzle with Fluid Operated Cleaning Member&#34; in the cleaning position and includes new parts. 
    
    
     DESCRIPTION 
     FIGS. 1 and 2 show the working and structural parts of my invention and are as follow: 
     1. Nozzle holder assembly 
     2. Schematic view of the directional control fluid valve 
     3. Inlet conduit from the source 
     4. Outlet conduit and return conduit to the source (new) 
     5. Outlet conduit and return conduit to the source 
     6. Supply conduit for the upper chamber 
     7. Supply conduit for the lower chamber 
     8. Upper chamber 
     9. Lower chamber 
     10. Nozzle orifice 
     11. Connector (connects punch with diaphragm with a press fit and also serves as a stop (new) 
     12. Seal--washer shaped device constructed of a rubber-like material (new) 
     13. Control lever for directional control fluid valve (schematic view) 
     14. Stop--a minor adjustment of the shape of the lower end of the guide structure (new) 
     15. A spacer in the shape of a cylinder, surrounding the punch above the diaphragm (new) 
     In order to provide a ready and reliable escape for the trapped fluid in lower chamber 9 when the diaphragm is forced downward by the introduction of fluid into upper chamber 8, an outlet and return conduit 4 is provided. Upon the introduction of pressurized fluid into upper chamber 8, the diaphragm center is forced down. The fluid present in lower chamber 9 is easily and readily exhausted through supply conduit 7, through the lower section of directional control fluid valve 2, and finally through outlet conduit 4 to the source. 
     In the operation of the &#34;Agricultural Spray Nozzle with Fluid Operated Cleaning Member&#34; the diaphragm-punch assembly has the freedom to move as far as the structural elements will allow, the only other limiting factor being the strength and elasticity of the diaphragm. In order to provide a more reliable and a more durable device and to encourage a longer diaphragm life, a stop 14 and a spacer 15 have been added. The stop 14 consists of a change in the manufacture of that portion of the nozzle holder assembly which contains the guide leaving the bottom portion of the structure of the guide in a shape and form that will fit and stop the upward movement of spacer 15. Spacer 15 is merely a block of material of sufficient rigidity to stop the upward movement of the diaphragm center when it contacts stop 14. Spacer 15 can be shaped as a cylinder and fits around the punch at a point between the diaphragm and the lower end of the guide, referred to above as stop 14. Spacer 15 is of such a length so as to stop the diaphragm-punch assembly&#39;s upward movement at a point where the punch is completely removed from the orifice 10 and no longer interferes with the flow of fluid entering orifice 10. 
     The connector 11 serves as a movement limiting device which stops the downward movement of the diaphragm center at a point, after the punch has entered, moved through, and where said punch extends beyond lower extremity of orifice 10. This stopping action is effected when the lower end of connector 11 comes in contact with the structure which surrounds nozzle orifice 10. Although connector 11 was shown in my prior application (Ser. No. 4,617) it was not referred to in this respect and was not claimed as a movement limiting device. 
     In use, when the &#34;Agricultural Spray Nozzle with Fluid Operated Cleaning Member&#34; is in the position shown in FIG. 2, dripping is minimized, however dripping is not stopped. The addition of a flexible, pliable, rubberlike washer 12, glued or otherwise attached to the lower end of connector 11 causes a drip-proof seal when connector 11 is moved downward to a point where it presses washer 12 against the structure which surrounds nozzle orifice 10. Connector 11 is shortened approximately half the thickness of washer 12 in order to keep the same distance of downward movement of the punch.