Abstract:
An insert body ( 10 ) for a spray nozzle assembly ( 1 ) has a fan jet producing section ( 17 ) for producing an oscillating, large-area fan jet and a point jet producing section ( 18 ) for producing at least one point jet located in the wetting area of the fan jet. It is thereby ensured that even if the fan jet collapses or is pushed aside, the surface is wetted at least by the or each point jet, which are much more forgiving from a fluid dynamics standpoint.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a U.S. National Phase Patent Application based on International Application Ser. No. PCT/EP2008/000507 filed Jan. 24, 2008, the disclosure of which is hereby explicitly incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to an insert body for a spray nozzle assembly, and to a spray nozzle assembly equipped with such an insert body. 
     2. Description of the Related Art 
     One insert body for a spray nozzle assembly is known from U.S. Pat. No. 4,463,904 A. The prior insert body comprises a fan jet producing section, which can be impinged on by a fluid via an insert entrance channel and is adapted to produce an oscillating fan jet, issuing from a fan jet exit opening, in order to wet a surface, typically the windshield of a motor vehicle. Although a relatively large-area fan jet can be produced under certain temperature conditions by means of a spray nozzle assembly equipped with such an insert body, there is a problem in that in the presence of unfavorable fluid mechanical boundary conditions, for example a low temperature or a high relative speed of the spray nozzle assembly compared to the surrounding medium, as is the case, for example, with a vehicle traveling at a relatively high speed, the fan jet fails to form or, due to the wind pressure, fails to impinge on the areas of the windshield that are to be wetted down. 
     SUMMARY OF THE INVENTION 
     The present invention provides an insert body for a spray nozzle assembly, by means of which a surface can be wetted reliably even under unfavorable boundary conditions. 
     This object is further achieved according to the invention, in connection with a spray nozzle assembly, by means of a spray nozzle assembly comprising an insert body according to the invention. 
     Because the insert body comprises, in addition to the fan jet producing section, a point jet producing section whose antechamber is in fluid mechanical communication with the insert entrance channel and is able to emit fluid in the direction of the fan jet via at least one point jet channel, there is, in addition to the fan jet, which is more sensitive to external influences, at least one point jet that can usually be produced without problems of any kind and is therefore reliably present, and which wets the windshield at least satisfactorily even if the fluid jet collapses due to unfavorable fluid mechanical boundary conditions or is pushed aside by high wind pressure. 
     In one form thereof, the present invention provides an insert body for a spray nozzle assembly for wetting a surface, including a fan jet producing section able to be impinged on by fluid via an insert entrance channel and provided to produce an oscillating fan jet that issues from a fan jet exit opening, characterized in that a point jet producing section is present that includes a collection chamber, which is in fluid mechanical communication with the insert entrance channel and which has at its disposal at least one point jet channel extending from the collection chamber and from a point jet exit opening and provided to produce at least one point jet in the direction of the fan jet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a graphic perspective view of a spray nozzle assembly with an insert body according to the invention for producing a fan jet and two point jets; 
         FIG. 2  is a front view of the spray nozzle assembly according to  FIG. 1 ; 
         FIG. 3  is a partially cut-away side view of the spray nozzle assembly according to  FIG. 2 ; 
         FIG. 4  is a section through the insert body according to the exemplary embodiment of  FIG. 3  along line IV-IV; and 
         FIG. 5  is a section through the insert body according to the exemplary embodiment of  FIG. 3  along line V-V. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
     DETAILED DESCRIPTION 
       FIG. 1  is a graphic perspective view of one exemplary embodiment of the invention, comprising two identically constructed spray nozzle assemblies  1 , which are connected in the region of a windshield  2  to a hood  3  of a motor vehicle. As can readily be seen from  FIG. 1 , each spray nozzle assembly  1  serves to produce, in a manner described in more detail below, a fan jet  4 , which extends from the particular spray nozzle assembly  1  over a relatively broad range of angles transverse to the direction of travel, said range typically being about 20 degrees to about 50 degrees, in a plane intersecting the surface of the windshield  2 , and a first point jet  5  and a second point jet  6 , each of which preferably extends from said spray nozzle assembly  1  approximately midway between the center line of the fan jet  4  and its edges and impinges on the windshield  2  in the manner of a filiform jet of fluid with a continuous, volume-conveying core. 
       FIG. 2  is a front view of a spray nozzle assembly  1  according to the exemplary embodiment of  FIG. 1 . The spray nozzle assembly  1  comprises a nozzle body  7  on which is formed an adapter  8  for effecting connection to a fluid delivery system not shown in  FIG. 2 . Configured on the opposite side of nozzle body  7  from adapter  8  is a nozzle body  9 , into which an insert body  10  according to the invention is fitted sealingly in terms of fluid mechanics. 
     It can be seen from  FIG. 2  that the one-piece insert body  10  is configured with a rectangular end face  11 , which is turned toward the viewer in the representation according to  FIG. 2 , and which is penetrated by a narrow, rectangular fan jet exit opening  12 , disposed adjacent a long edge side and extending from that long edge side into approximately the center of the end face  11 . Configured on the other long edge side of the end face  11  are a first point jet exit opening  13  and a second point jet exit opening  14 , which are configured as semicircular and open toward the particular long edge side, and are arranged symmetrically one on each side of the fan jet exit opening  12 . 
       FIG. 3  shows the spray nozzle assembly  1  according to  FIG. 2  in a side view, which is cut away in the region of insert body  10 . It can be appreciated from  FIG. 3  that a delivery channel  15  extending from adapter  8  through nozzle body  7  opens into an insert entrance channel  16  configured in insert body  10  on the opposite side of insert body  10  from end face  11 , which insert entrance channel  16  extends over the entire thickness direction of the square-shaped insert body  10  and is sealed on the side facing away from delivery channel  15  by the nozzle head  9 . 
     Insert entrance channel  16  is connected to a fan jet producing section  17  and to a point jet producing section  18 , both of which—fan jet producing section  17  and point jet producing section  18 —extend from insert entrance channel  16  to end face  11  and are open to the outside of the insert body  10 , with the result that the nozzle body  9  performs the function of sealing insert body  10  to the outside, while inside the insert body  10 , a partition  19  is provided between fan jet producing section  17  and point jet producing section  18 . 
     It can be appreciated from  FIG. 3  that fan jet producing section  17  comprises an antechamber  20  of constant height, which on the one side is in communication with insert entrance channel  16 , and which, on the side remote from insert entrance channel  16 , gives way to an expansion chamber  21  whose height increases from antechamber  20  toward end face  11 . 
       FIG. 4  shows the insert body  10  according to  FIG. 3  in section along line IV-IV, located in the region of fan jet producing section  17 . It can be appreciated from  FIG. 4  that the antechamber  20  narrows in width from the insert entrance channel  16  toward the expansion chamber  21 , and that configured one on each side of expansion chamber  21 , in the end region proximate end face  11 , are return channels  24 ,  25  that begin with outward-bulging pressure pulse return regions  22 ,  23 , and open into an intersection region  26  configured in the constriction between antechamber  20  and the expansion chamber  21 , which broadens gradationally in width in the direction of end face  11 . A fan jet exit channel  27  extends centrally from the end of expansion chamber  21  proximate end face  11 , and broadens in width from expansion chamber  21  to fan jet exit opening  12 . 
     With this construction of the fan jet producing section  17 , a pressure pulse in intersection region  26  can, in a manner known per se, be coupled via pressure pulse feedback from the side of expansion chamber  21  proximate end face  11  through pressure pulse return regions  22 ,  23  and return channels  24 ,  25  into intersection region  26  and fed back into expansion chamber  21 , and leads, by reflection from the gradationally widening boundary surfaces of expansion chamber  21 , which are formed on separating walls  28 ,  29 , to the shape of the fan jet  4  described and illustrated in connection with  FIG. 1 . 
       FIG. 5  shows the insert body  10  according to  FIG. 3  in section along line V-V located in the region of point jet producing section  18 . It is evident from  FIG. 5  that configured in point jet producing section  18  is a collection chamber  30  that extends from insert entrance channel  16  toward end face  11 , initially with a constant and thereafter a widening cross section. Opening into collection chamber  30  on the side remote from insert entrance channel  16  are two point jet channels  31 ,  32 , which are disposed symmetrically to a central longitudinal axis and have a substantially smaller cross section than the cross section of collection chamber  30  in the region remote from insert entrance channel  16 , and each of which opens into a respective fan jet exit opening  13 ,  14 . By virtue of this configuration of point jet producing section  18 , directed point jets emerge from point jet exit openings  13 ,  14  and undergo relatively little widening over the path of the jet, yielding the shape of the point jets  5 ,  6  explained and illustrated in connection with  FIG. 1 . 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.