Patent Publication Number: US-8985483-B2

Title: Adjustable trajectory spray nozzles

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of U.S. provisional application No. 61/590,008, entitled “Adjustable Trajectory Spray Nozzles” filed Jan. 24, 2012, and the entire disclosures of which is hereby specifically incorporated by reference for all that it discloses and teaches. 
    
    
     BACKGROUND OF THE INVENTION 
     It is common for most spray devices such as showers, garden sprayers, etc. to offer the user a device which has more than one spray pattern. Most typically these devices provide for the use of multiple spray patterns by selection of alternate sets of outlet flow nozzles or orifices. Potential disadvantages of using alternate sets of outlets are the added difficulty of manufacturing control for each set, additional space required in the device for each set of orifices, generally the use of more sealing members to prevent undesired leakage between set of orifices, and additional parts to permit the selection of each set of orifices, etc. 
     In some cases, these sets of outlet flow nozzles or orifices may consist of just one nozzle or orifice. In other cases, the outlet set will consist of multiple individual orifices, each producing its own individual jet. Advantages of outlet sets consisting of multiple individual orifices are droplet size, which is better controlled, and the distribution of the issuing fluid can be more predictably controlled. These advantages provide particular value for the personal shower user where certain spray droplet sizes and distribution of these droplets can provide for a more enjoyable showering experience. 
     In recent years, shower manufacturers, in particular, have employed elastomeric or rubber-like materials in their products as part of the product to produce the final spray patterns. One reason for doing this is that if particles block the spray opening or deposits, i.e. mineral-type, collect in the vicinity of the opening, these obstructions can be removed by deforming the rubber-like feature. Generally, these rubber-like materials are used in conjunction with other more rigid materials to support the flexible material against the imposing fluid pressure. Without the use of more rigid materials, the elastomeric or rubber material is likely to excessively deform and render the product unusable with higher fluid pressures. 
     SUMMARY OF THE INVENTION 
     An embodiment of the present invention may therefore comprise: a fluid spray control device that produces a variety of fluid spray patterns comprising: a housing that forms an enclosed flow path interface between a pressurized fluid source and at least one flexible member comprising at least one flexible flow channel, the flexible flow channel having an inlet, a protruded, approximately cylindrical axis with a length which is greater than diameter, and an outlet thereby forming a nozzle; a manifold within the housing that distributes the fluid to at least one nozzle; a rigid support plate that supports and retains the flexible member with the manifold; a deflecting member that when engaged, contacts at least a portion of the flexible flow channel to deflect the direction of the flow channel thereby changing the angle of trajectory of the fluid exiting the nozzle. 
     An embodiment of the present invention may also comprise: a hand shower device that produces a variety of fluid spray patterns comprising: a housing that forms an enclosed flow path interface between a pressurized fluid source and a flexible member comprising a disk containing a plurality of flexible flow channels, the flexible flow channels each having an inlet, a protruded cylindrical axis with a length which is greater than diameter, and an outlet thereby forming individual nozzles that extend beyond the distal surface of the disc; a manifold within the housing that supplies the fluid into the nozzles; a rigid support plate that supports and retains the flexible member with the manifold; a deflecting member that that when engaged, contacts some or all of the flexible flow channels to deflect the direction of the flow channels thereby changing the angle of trajectory of the fluid exiting the nozzles; an alignment member that contacts the flexible flow channels and allows limited and specific deflection angles and position of the flexible flow channels; a lower support member that retains the alignment member, the deflecting member, the rigid support plate and the manifold with the housing. 
     An embodiment of the present invention may therefore comprise: a method of producing a variety of fluid spray patterns that issue from a plurality of flexible nozzles comprising: introducing a fluid under pressure to a manifold that distributes the fluid to a flexible member; supporting and retaining the flexible member to the manifold with a rigid support plate; flowing the fluid through the plurality of flexible flow channels in the flexible member; producing a first fluid spray pattern of the fluid exiting the nozzles with the flexible flow channels each having an inlet, a protruded cylindrical axis with a length which is greater than diameter, and an outlet thereby forming individual nozzles; contacting some or all of the flexible flow channels with a deflecting member to deflect some or all of the flow channels to a modified angle of trajectory; producing a second fluid spray pattern of the fluid exiting the nozzles with the flexible flow channels that have been deflected with the deflecting member to the modified angle of trajectory. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, 
         FIG. 1A  schematically illustrates an embodiment of a hand shower with an adjustable trajectory spray nozzle. 
         FIG. 1B  is an exploded view of the embodiment of the hand shower depicted in  FIG. 1A  with the lower support member, elastomeric member and upper support member shown in detail. 
         FIG. 1C  shows a cross section view thru the head of the shower depicted in  FIG. 1A . 
         FIG. 2A  schematically illustrates the fluid flow thru orifices with angled side walls. 
         FIG. 2B  illustrates the fluid flow thru straight walled orifices whose axes are oriented at an angle to the outer surface of the member with the orifice holes. 
         FIG. 3A  schematically illustrates an exploded isometric view of the components utilized for controlling the direction of fluid flow thru an elastomeric member by deflecting a boss. 
         FIG. 3B  illustrates the fluid flow direction when the elastomeric member of  FIG. 3B  is in an undeflected condition. 
         FIG. 3C  illustrates the fluid flow direction when the elastomeric member of  FIG. 3B  is in the deflected position. 
         FIG. 4A  schematically illustrates another embodiment of an exploded isometric view of a set of components for controlling the direction of fluid flow thru an elastomeric member. 
         FIG. 4B  illustrates the fluid flow direction when the elastomeric member of  FIG. 4A  is in an undeflected condition. 
         FIG. 4C  illustrates the fluid flow direction when the elastomeric member  FIG. 4A  is in a deflected position. 
         FIG. 5A  schematically illustrates an embodiment of an isometric view a hand shower. 
         FIG. 5B  is an exploded, isometric view of the hand shower  FIG. 5A . 
         FIG. 5C  is a cross section view at mid-plane of the shower product shown in  FIG. 5A . 
         FIG. 5D  is an enlarged view of a portion of the cross sectional view of  FIG. 5C . 
         FIG. 5E  is an enlarged view of a partial section of the center of the assembly of the embodiment depicted in  FIG. 5C . 
         FIG. 6A  schematically illustrates a view looking thru the top surface of the shower head with that surface removed. 
         FIG. 6B  is an exploded view of the components of  FIG. 6A . 
         FIG. 7A  schematically illustrates an isometric view of the upstream surface of the elastomeric member of the disclosed embodiments. 
         FIG. 7B  is a bottom plane view of the downstream surface of the elastomeric member of the disclosed embodiments. 
         FIG. 7C  is a partial cross sectional view of the elastomeric member taken thru the view direction shown in  FIG. 7B . 
         FIG. 8A  schematically illustrates an isometric view of the upstream surface of the lower support plate of the disclosed embodiments. 
         FIG. 8B  is a plane view of the upstream surface of the lower support member of the embodiment depicted in  FIG. 8A . 
         FIG. 8C  is a partial cross section view of the embodiment of  FIG. 8A , thru the lower support member with the elastomeric member assembled on top of the upstream surface of the support member. 
         FIG. 9A  schematically illustrates an isometric view of the upstream surface of the upper alignment member of the disclosed embodiments. 
         FIG. 9B  is a plane view of the upstream surface of the upper alignment member of  FIG. 9A . 
         FIG. 9C  is an isometric view of a partial cross sectional area taken thru the assembly of the lower support member, elastomeric member, and the upper alignment member of  FIG. 9A . 
         FIG. 10A  schematically illustrates an isometric view of the deflecting member of the disclosed embodiments. 
         FIG. 10B  is a plane view of the downstream surface of the deflecting member of  FIG. 10A  illustrating a spiral cutout section. 
         FIG. 10C  is a partial cross sectional view of an assembly of the lower support member, the elastomeric member, the upper alignment member and the deflecting member of  FIG. 10A . 
         FIG. 11A  schematically illustrates a plane view looking at the upstream surface of the deflecting member in the assembly of the lower support member, elastomeric member, upper alignment, and the deflecting member. The Illustration depicts the alignment of the deflecting member so as not to interfere with the upstanding features or bosses of the elastomeric member. 
         FIG. 11B  is an enlarged view of the area detailed in  FIG. 11A . 
         FIG. 11C  is a plane view of the hand shower containing the disclosed embodiments with the resulting, approximate trajectory of the issuing fluid streams as shown for the assembly shown in  FIG. 11A . 
         FIG. 12A  schematically illustrates a plane view looking at the upstream surface of the deflecting member in the assembly of the lower support member, elastomeric member, upper alignment member, and the deflecting member with the tab on the lower product support member being rotated counter clockwise. 
         FIG. 12B  is an enlarged view of the inner most bosses in the elastomeric member and  FIG. 12C  is an enlarged view of the outer most bosses in the elastomeric member of  FIG. 12A . 
         FIG. 12D  is a plane view of an embodiment view of the hand shower with the resulting, approximate trajectory of the issuing fluid streams as shown with the lever of the lower support member rotated as shown in  FIG. 12A . 
         FIG. 13A  schematically illustrates a plane view looking at the upstream surface of the deflecting member in the assembly of the lower support member, elastomeric member, upper alignment member, and the deflecting member with the tab on the lower support member being rotated in a clockwise direction. 
         FIG. 13B  is an enlarged view of the inner most bosses in the elastomeric member. 
         FIG. 13C  is an enlarged view of the outer most bosses in the elastomeric member of  FIG. 13A . 
         FIG. 13D  is a plane view of an embodiment of the hand shower with the resulting, approximate trajectory of the issuing fluid streams as shown with the lever of the lower support member rotated as shown in  FIG. 13A . 
         FIG. 14A  schematically illustrates another embodiment of a hand shower. In this embodiment, an exploded isometric view, with a small cutaway section, depicts an embodiment where the relative movement between a deflecting member and an elastomeric member is achieved by using a knob to rotate the deflecting member. 
         FIG. 14B  illustrates an isometric view of a cutaway of the hand shower showing the engagement between the knob and the deflecting member of  FIG. 14A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is susceptible to embodiment in many different forms, it is shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not to be limited to the specific embodiments described. 
     The disclosed embodiments utilize a method and apparatus to control a spray pattern produced from a spraying device consisting of a plurality of individual jets that form the resulting spray pattern. The trajectory of each individual jet is controlled by orienting the nozzle-like feature that produces each individual jet, thereby producing a variety of spray patterns. This is accomplished utilizing the flexible properties of elastomeric or rubber-like materials. In addition to allowing for deformation or movement to remove possible obstructions to the fluid flow, this flexibility property also permits for specific, controlled movements whereby it is possible to control the trajectory of the fluid issuing from the device. These rubber-like materials can include specific features that allow the material to be deformed in a controlled fashion so as to predictably position the trajectory of the streams issuing from the individual nozzles. 
     While rubber or elastomeric materials can generally experience considerably more movement or flex without breakage or damage than other more rigid materials, these materials do have limits of motion if long product life is to be realized. The disclosed embodiments utilize these material limitations and translate this understanding to a novel design. 
     Reference is made to  FIGS. 1A ,  1 B and  1 C showing a typical application featuring an elastomeric member in a hand shower  100  held by a user with a gripping handle  102 . The elastomeric member  104  is assembled on top of a downstream support plate  106 . In the current configuration, an upstream support member  108  is provided to contain the elastomeric member fixed in the assembly. The elastomeric member  104  is deformed by the user by contacting the outer portion of the elastomeric member  104 . 
     The trajectory of streams issuing from a pressurized fluid container can be controlled in a rigid material member by the device shown in  FIGS. 2A and 2B .  FIG. 2A  shows a technique employed in molding parts featuring straight core pulls. The sidewalls of the orifice, shown as  110  and  112 , are angled relative to the surface normal, shown as the dashed line  116 , but at a positive value of the angle. The trajectory of the issuing stream  114  is at an angle intermediate to the sidewall angles, since this angle of the issuing fluid is determined by the average fluid momentum flux. Another option to control trajectory is to create flow paths thru orifices  120  at the desired trajectory angle as shown in  FIG. 2B . 
     The disclosed embodiments control issuing stream trajectories by orienting the flow channel in an elastomeric member  122 . Because this member  122  is elastomeric, a flexible flow channel can be created. Reference is made to  FIGS. 3A ,  3 B and  3 C for a simplified representation of one such device. The elastomeric member  122  has an upstanding feature, referred to as a boss  124 , and a convoluted lower feature  126 . The support member  128  supports the elastomeric member  122  against the fluid pressure. Positioned atop the elastomeric member  122  is a moveable member  130  capable of interfering with the boss member  124 . When the moveable member  130  is positioned so as not to contact the boss member  124 , the fluid trajectory is normal to the flat outer surface of the support member  128  as shown by the arrow  123  in  FIG. 3B . However, when the moveable member  130  is positioned to interfere with the boss  124 , the fluid trajectory, shown by the arrow  121 , is altered to some angle, the value of which will depend upon the resulting deflection and deformation of the boss  124  as shown in  FIG. 3C . 
       FIGS. 4A ,  4 B and  4 C show another embodiment to alter the stream trajectory of an elastomeric member  134 . In this embodiment, a supporting member  132  provides a method to support the elastomeric member  134  against the internal fluid pressure. Positioned below the supporting member  132 , is a moveable member  136  which has a flat surface  138  to support the convoluted surface of the elastomeric diaphragm  140 . When the moveable member  136  is positioned so that the flat surface  138  is supporting the convolution  140 , there is no deformation of the elastomeric member  134 , and the issuing fluid trajectory is as shown by the arrow  142  in  FIG. 4B . This moveable member  136  also has a raised feature  144  on its supporting surface  138 . When the moveable member  136  is positioned so that the raised surface  144  contacts a portion of the convoluted surface  140 , the elastomeric member  134  is deformed or deflected, and the fluid trajectory is altered as shown by the arrow  146  in  FIG. 4C . The above disclosure is not limited by the manner in which the elastomeric member is deformed or deflected thereby altering the issuing stream trajectory. 
     Reference will now be made to  FIG. 5  thru  FIG. 13  to describe the present embodiments.  FIG. 5A  schematically illustrates an isometric view of an embodiment of a hand shower.  FIG. 5B  shows an exploded view of the components of the hand shower in  FIG. 5A . A handle  160  is attached to the housing  168  to form the fluid housing, although an integral construction of the handle  160  and housing  168  is an alternative option. Extended bosses  166  integral in the housing  168  align with ribs  164  of the deflecting member  162 . When the ribs  164  engage extended bosses  166 , the deflecting member  162  is prevented from rotating in the housing  168 . An alignment plate  156  is positioned on top of the elastomeric member  154  and serves to provide alignment for the elastomeric member  154 . The elastomeric member  154  is positioned on top of the support member  152  which provides a supporting restraint against the fluid pressure. A tab  158  is attached to the support member  152  and provides a method in which the support plate  152  can be rotated. A retaining ring  148 , which contacts the outer surface of the support member  152 , is attached to the housing  168  via a thread  170 , and thereby secures the components into the housing  168 . A seal  150 , which contacts both support plate  152  and retaining ring  148 , prevents leakage of fluid to the outside.  FIG. 5C  shows a cross section view of the hand shower shown is  FIG. 5A .  FIG. 5D  shows and enlarged view of the cross section view of  FIG. 5C . A retaining ring  148  engages the housing  168  via a set of threads  170 . 
     The seal  150  contacts the inside surface of the retaining ring  148  and the outside surface of the support member  152  thereby preventing fluid leakage. A protruding boss  182  on the alignment plate  156  assembles into a recess  178  of the support member  152  and provides a method to align these respective parts. The boss feature  172  of the elastomeric member  154  is positioned in the opening (slot  180 ) of the alignment plate  156 , and between sidewalls of the deflecting member  162 .  FIG. 5E  shows an enlarged partial view of the cross section shown in  FIG. 5C . Here a protruding center boss  190  of the deflecting member  162  is positioned into the central recess  192  of the alignment member  156 , thereby providing axial alignment for these parts. 
       FIG. 6A  shows the upstream surface of the deflecting member  162  with the top surface of the housing  168  removed. It is shown in this view that ribs  164  of deflecting member  162  are engaged by the protruding ribs  166  of the housing  168 . This engagement prevents the rotation of the deflecting member  162  relative to the housing  168 .  FIG. 6B  shows the major components of the disclosed embodiment. The deflecting member  162  is positioned on top of the alignment member  156  which is positioned on top of the elastomeric member  154 . The support member  152  provides structural support to the elastomeric member  154 . 
       FIG. 7A  shows an isometric view of the upstream surface of the elastomeric member  154  with the upward extending bosses  172 .  FIG. 7B  shows a plane view of the upstream surface of the elastomeric member  154 .  FIG. 7B  also shows the spiral path  194  along which each of the boss-like features  172  and convoluted surfaces  174  shown in  FIG. 7C  are distributed. The boss  172  features allow the flow path to be deflected and the convoluted surfaces  174  allow the boss  172  deflection to occur over a more widely distributed area, thereby reducing stresses incurred during the deflection process. These features are shown in the cross sectional view of  FIG. 7C . 
       FIG. 8A  is an isometric view of the upstream surface of the lower support member  152 .  FIG. 8A  shows the concave recesses  176 , which are distributed along the same spiral path  194  as shown in the elastomeric member  154 . These concave recesses provide support against the fluid pressure for the convoluted surfaces  174  of the elastomeric member  154 .  FIG. 8B  shows a plane view of the upstream surface of the support lower support member  152 . Small recesses or pockets  178  are also seen in  FIG. 8B  to receive the protruding alignment features  182  of the alignment member  156 .  FIG. 8C  is a cross sectional view of the elastomeric member  154  and the support member  152 . Feature  184  is a groove for a sealing member. Concave recesses  176  are shown providing support to the elastomeric member  154 . 
       FIG. 9A  shows an isometric view of the upstream surface of the alignment member,  156  along with the slotted holes  180  distributed along the same spiral path  194  as that of the elastomeric member  162 . Also, a small, cylindrical recess  192  is present at the center of the part and is used to help align the axes of the deflecting member  162  and the alignment member  156 .  FIG. 9B  is a plane view of the downstream surface of the alignment member  156  showing the orientation of these slotted holes  180  such that the centerline axis of the slotted holes, indicated by arrows  196 , is pointing toward the center axis  198  of the alignment member  156 . Since the bosses  172  of the elastomeric member  154  protrude thru these slots  180 , it can be seen that the bosses  172  can only move along the path of this slot  180 . This is also illustrated in  FIG. 9C . Additionally,  FIG. 9B  shows four small protruding boss features  182 , which assemble into the small recesses  178  of the lower support member  152 , thereby locking the alignment plate to the lower support plate and preventing relative rotation between the lower support member  152 , the elastomeric member  154 , and the alignment member  156 . 
       FIG. 10A  illustrates an isometric view of the upstream surface of the deflecting member  162 . A slot  202  is present in the deflecting member, and its centerline follows the same spiral path  194  of the elastomeric member  154 . Ribs  164  provide means to stiffen the deflecting member  162 , as well as a way to prevent rotation when engaged by the extending bosses  166  of the housing  168 . As can be seen in  FIG. 10B , the width of this slot  204  at the outer most portion is narrower than the width at the inner most portion  205 . This variation in width is determined by the design intent, and the result of this variation will become apparent later in the discussion. Also, a small protruding cylindrical boss feature  190  is seen and this boss is assembled into a cylindrical recess feature  192  of the alignment member  156  to provide axes alignment between this member and the deflecting member  162 .  FIG. 10C  is a cross sectional view of the assembly of the lower support member  152 , the elastomeric member  154 , the alignment member  156  and the deflecting member  162 . Feature  184  is the groove for the sealing member  150 . 
     Reference is now made to  FIG. 5D . The elastomeric member  154  is assembled into the lower support member  152 , making sure that the convoluted surfaces  174  of the elastomeric member  154  is align with the concave recesses  176  of the support member  152 . Assembly in this manner will prevent relative rotation between the two members,  154  and  152 . Alignment member  156  is then position so that the bosses  172  of elastomeric member  154  protrude thru the slots  180  in the alignment member, and also that protruding bosses  182  of the alignment member fit into the recesses  178  of the lower support member  152 . The deflecting member  162  is also positioned so that the sidewalls of the spiral slot  202  in the deflecting member  162  are not contacting the bosses  172  of the elastomeric member  154 , as shown in  FIG. 5D . Referring now to  FIG. 5E , the deflecting member  162  is then positioned so that the small protruding cylindrical feature  190  of the deflecting member  162  fits into the small cylindrical recess  192  of the lower support plate  152 . 
       FIG. 11B  shows this alignment, as there is clearance between the boss  172  surfaces and the sidewalls  188  of the spiral slot as shown at locations  206 . The ribs  164  of the deflecting plate are then oriented so as to fit between the protruding features  166  of the housing,  168  as the assembly is inserted into the housing  168  as shown in  FIG. 6A . This assembly prevents relative rotation between the deflecting member  162  and the housing  168 . The lower support plate  152 , elastomeric member  154  and upper alignment member  156  are still free to rotate as an assembly, with the rotation occurring at the interface between the upstream surface of the alignment member  156  and the downstream surface of the deflecting member  162 . Seal member  150  is then positioned in the groove  184  of the lower support plate  152  and this assembly is then held in place as the retaining ring  148  is assembled to the thread  170  of the housing  168 . 
     Actual operation of the disclosed invention is described as follows. When then deflecting member  162  is oriented relative to the elastomeric member  154 , such that there is no contact between the spiral slot sidewall surfaces  188  in the deflecting member  162  and the bosses  172 , the bosses  172  maintain their natural alignment. In this case the issuing fluid flow trajectory is in a direction normal to outer face of the lower support member  152  and is shown by the arrows  208  in  FIG. 11C . 
     If the tab  158  of the lower support member  152  is rotated in a counter clockwise direction, as shown in  FIG. 12A , the sidewall surfaces  188  of the spiral slot  202  will begin to contact the surfaces of the outer-most bosses  212  of the elastomeric member  154 . Since the outer-most portion of the slot  204  is narrower than the inner portion  205 , contact will first be made with the outer-most bosses  212 . With continued rotation of the deflecting member  154 , the outer-most bosses  212  will experience greater contact as indicated by the regions of interference  171  when compared to the contact at region  210  as shown in  FIGS. 12B and 12C . As a result of this greater contact and interference, the outer bosses  212  will undergo a greater deflection than the innermost bosses,  214 . Because of the presence of the alignment member  156 , the bosses  172  can only move in a direction along the slots  180 . As a result, the upper ends of the bosses  172  are deflected toward the center of the assembly, which further results in the effective flow axis of the bosses  172  being angled away from the center axis, with the outer-most bosses&#39;  212  axes having a greater angular change than the inner bosses  214 . The resulting trajectory of the issuing streams will be as shown by the arrow  216  in  FIG. 12D . 
     If the tab  158  of the lower support member  152  is rotated in a clockwise direction as shown in  FIG. 13A , the sidewall surfaces  216  of the spiral slot  202  will begin to contact the inside surfaces  222  of the outer-most bosses  212  of the elastomeric member  154 . Since the outermost portion of the slot  204  is narrower than the inner portion  205 , contact will first be made with the outer-most bosses  212 . With continued rotation of the deflecting member  162 , the outer-most bosses  212  will experience greater contact as indicated by the region of interference shown as  220  in  FIG. 13C  as compared to the region of interference  218  shown in  FIG. 13B . As a result, the outer most bosses  212  will undergo a greater deflection. Again, because of the presence of the alignment member  156 , the bosses can only move in a direction along the slots  180 . This also results in the upper end of the bosses  172  being deflected away from the center of the assembly. Thus, the effective flow axis of the bosses  172  is being angled toward the center axis, with the outer most bosses&#39;  212  axes having a greater angular change than the inner bosses  214 . This allows the stream to be directed to converge at a point at some chose distance from the face of the lower support member  152 . The resulting trajectory of the issuing streams will be as shown by the arrows  224  in  FIG. 13D . 
     The previously disclosed embodiments utilize a design where a deflecting member is held in a stationary position, and a lower support member can be rotated to produce a deflection to the boss thereby changing the issuing stream trajectories.  FIG. 14A  discloses an alternative embodiment where the deflecting member  236  is rotated by a knob  226  assembled thru a hole  234  in the back of the housing  168 . In this example, the lower support member  238  would not be required to rotate. The retaining ring  230  is used to restrain the knob  226  in position in the housing. A seal  232  would be utilized to prevent leakage around the knob stem  228 .  FIG. 14B  illustrates a method by which the slot  240  in the knob  226  could engage the intersection of the deflecting plate ribs  236 , thereby allowing the knob  226  to rotate the deflecting plate  162 . 
     The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.