Abstract:
An agricultural sprayer includes a spray boom equipped with a plurality of spray heads, with each head having a body defining a cavity located in fluid communication with a fluid inlet and an array of four outlets leading to four nozzles respectively having different flow rates. A nozzle-select control member is mounted for rotation in the cavity and includes a fluid passage arrangement for establishing fluid connections between the inlet and different ones or combinations of the four nozzles as the control member is rotated among preselected discrete positions by an electric stepper motor, with the stepper motor being controlled in response to vehicle speed so that the spray tip capacity decreases for effecting a constant application rate as the vehicle speed decreases from a maximum permitted speed.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to agricultural sprayers, and more specifically relates to automatically controlling the spray rate from a spray head for compensating for changes in vehicle ground speed so as to maintain a constant application rate. 
       BACKGROUND OF THE INVENTION 
       [0002]    Agricultural sprayers use nozzles for spraying a liquid which may be a fertilizer, a pesticide, a fungicide, or an insecticide, for example, onto agricultural crops. Traditional nozzles consist of an orifice with geometry controlling the flow rate, droplet size and spray pattern to the target. The flow rate through the orifice is mainly a function of the orifice area and geometry as well as the fluid pressure at the orifice (i.e., pressure just prior to the orifice). Since the orifice size is fixed, i.e., the orifice geometry doesn&#39;t change, the most common way to influence the flow rate through the nozzle is by changing pressure. 
         [0003]    Changing the fluid pressure at the nozzle to influence flow rate changes has become common place on sprayers in order to allow for variable vehicle speed. Systems change the flow rate proportional to the vehicle speed in order to keep the application rate the same. 
         [0004]    However, using the traditional fixed orifice nozzle has some limitations. The pressure versus flow relationship is a squared function. To double the flow requires increasing the pressure by a factor of four times. Unfortunately, changing pressure also changes atomization dynamics resulting in an impact on spray quality. Spray quality characteristics, namely, droplet size and the spray angle, both become smaller as pressure increases. These changes can negatively impact to spray deposit and spray drift. So, the need for a variable rate nozzle with uniform pressure has emerged. 
         [0005]    U.S. Pat. No. 7,124,964 discloses a nozzle arrangement including a flexible spray tip which may be manipulated by a driven metering member which acts to selectively change the spray tip configuration in response to changes in vehicle speed so as to change the spray tip spray rate for maintaining a desired application rate. This nozzle arrangement has the disadvantage of requiring a specialized nozzle construction instead of less costly standard nozzle configurations. 
       SUMMARY OF THE INVENTION 
       [0006]    According to the present invention, there is provided a novel spray head including a nozzle arrangement for maintaining a desired application rate. 
         [0007]    An object of the invention is to provide a spray head nozzle arrangement which automatically maintains a desired constant spray fluid application rate during changes in sprayer vehicle ground speed and which overcomes the above-noted disadvantages of the patented nozzle arrangement while maintaining the advantage of permitting the spray fluid to be supplied to the spray head nozzle arrangement at a constant pressure. 
         [0008]    This object is achieved by a spray head nozzle arrangement including a manifold body defining a cavity connected in fluid communication with a spray fluid inlet arrangement and a spray fluid outlet arrangement, with the outlet arrangement defining a plurality of passages having entrances defined as slots located in one or more circular patterns about an upright axis of rotation of a nozzle selector disk containing a plurality of slots located for being rotated into register with one or more of the entrance slots of the outlet arrangement, with the outlet arrangement leading to a plurality of standard nozzles carried by the body and respectively having spray tips designed for having different spray rates for a given pressure of the supplied spray fluid, whereby different spray rates are obtained by rotating the nozzle selector disk to different positions by a drive motor, with the drive motor being automatically controlled to rotate the nozzle selector disk to select one or more nozzles for effecting a spray rate corresponding to the spray vehicle speed so as to maintain a constant spray fluid application rate. 
         [0009]    This and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic showing a control system for automatically switching liquid spray fluid among a plurality of nozzles of a spray head for controlling the spray rate so as to maintain a constant application rate with varying travel speeds of the spray vehicle. 
           [0011]      FIG. 2  is a perspective view of a spray head including a switchable nozzle arrangement constructed in accordance with the present invention, but with the nozzles being removed from the nozzle connectors for the sake of simplicity. 
           [0012]      FIG. 3  is a vertical sectional view taken through the spray head of  FIG. 2  along a first plane passing through the inlet and a second plane passing through one of the four outlets, with the planes meeting at an axis of rotation of the nozzle selector disk of the nozzle arrangement. 
           [0013]      FIG. 4  is a bottom view of the spray head shown in  FIG. 2 . 
           [0014]      FIG. 5  is a top view of the flow direction control section of the nozzle arrangement shown in  FIG. 2 . 
           [0015]      FIG. 6  is a top view of the nozzle selector disk shown in  FIG. 2 . 
           [0016]      FIG. 7  is a horizontal sectional view taken through the flow direction control manifold body just above the lower flow direction control section of  FIG. 2  and looking downwardly and showing the fluid passage arrangement used to convey fluid from the flow direction selector slots of the selector disk to the four outlets leading to the nozzle connectors. 
           [0017]      FIG. 8  is a vertical sectional view taken through the lower flow direction control section of the manifold body along the lines  8 - 8  of  FIG. 7 , but with the lower portion of the upper inlet section and nozzle selector disk being removed for the sake of simplicity. 
           [0018]      FIG. 9  is a horizontal sectional view taken through the manifold body along the lines  9 - 9  of  FIG. 8 , but showing the entire manifold body. 
           [0019]      FIG. 10  is a horizontal sectional view taken through the manifold body along the lines  9 - 9  of  FIG. 7 , but showing the entire manifold body. 
           [0020]      FIGS. 11-26 , respectively, illustrate the sixteen positions of the nozzle selector disk for achieving each of sixteen spray rates from the spray head. 
           [0021]      FIG. 27  is a table showing the application rates achievable for each of the sixteen different selected positions of the nozzle selector disk shown in  FIGS. 11-26 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Referring now to  FIG. 1 , there is shown a schematic of a control system  10  for maintaining the application rate of an agricultural spray to a field substantially constant at different sprayer vehicle ground speeds. The control system  10  comprises a plurality of spray heads  12  (only one shown) which would be mounted in evenly spaced relationship to each other along the length of a sprayer boom (not shown). Each of the spray heads  12  includes a manifold body  14  having an inlet  16  coupled for receiving spray fluid from a supply tube  18  carried by the spray boom and coupled to an outlet of a supply pump  20  having an inlet coupled to a source of spray fluid contained within a spray fluid tank  22  carried by the sprayer vehicle. Four cylindrical, tubular nozzle connectors  24 ,  26 ,  28  and  30  (shown other than in actual locations of mounting for the sake of clarity), respectively, include upper ends secured to a lower surface of the manifold body  14  in fluid communication with four outlet openings, described below. Four conventional spray nozzles  32 ,  34 ,  36  and  38  are respectively coupled to lower ends of the connectors  24 ,  26 ,  28  and  30  by bayonet connections, for example, and respectively include spray tips  40 ,  42 ,  44  and  46  having different flow rates for a given spray fluid supply pressure. Instead of being configured for being mounted to the bottom of the connectors  24 ,  26 ,  28  and  30 , the manifold body and nozzles could be configured in any other suitable way to establish a connection of the nozzles with the four outlet openings, for example, the nozzles could be snap fit or threaded to the manifold body. 
         [0023]    A flow control valve is defined by a circular nozzle selector disk  48  and the manifold body  14  with the nozzle selector disk  48  being located within the manifold body  14  at a location between the inlet  16  and a flow direction control passage arrangement (described below) and is mounted for rotation about an upright axis of rotation. The flow direction control passage arrangement includes a plurality of slots (described below), which lead to and cooperate with passage ways (also described below) to define an outlet passage arrangement which lead to one or more of the nozzle connectors  24 - 30 , and hence to one or more of the spray nozzles  32 - 38 . 
         [0024]    The nozzle selector disk  48  is selectively positioned by automatic operation of a power-operated motor, which may be an electrically controlled pneumatic, hydraulic or electric motor, but is preferably an electrically powered stepper motor  52  mounted to a central location of a top surface of the manifold body  14  and has an output shaft  54  coupled, in a manner described in more detail below, to a central location of the nozzle selector disk  48 . The motor  52  is electrically coupled, as by a motor control signal lead  56 , for receiving electrical control pulses from a motor controller  58  as commanded by an electronic controller  60  coupled to the motor controller  56  by an output signal lead  62 . The electronic controller  60  may be a microprocessor having a memory into which field mapping data, for example, relating to potential yield, soil type, soil nutrients, soil moisture content, weeds, diseases, and field topography, may be stored along with corresponding spray fluid application rates. To go along with this mapping data, a GPS receiver  64  is coupled to the controller by a position input signal lead  66 . Also stored in the memory of the controller  60  is a look-up table containing data relating application rates of the nozzle tips  40 - 46  to ground speed of the spray vehicle. To go along with this data, a spray vehicle ground speed sensor  68  is coupled to the controller  60  by a ground speed input signal lead  70 . The type of spraying being done and the corresponding nozzle tips being used can be keyed into the memory of the controller  60  by a manually-operable data input device  72  that is coupled to the controller by a data input lead  74 . 
         [0025]    Referring now to  FIGS. 2 and 3 , there is shown the spray head  12  of  FIG. 1 , but with the nozzles  32 - 38  and associated spray tips being omitted for the sake of clarity. It can be seen that the stepper motor  52  includes a cylindrical housing  76  provided at its lower end with a horizontal mounting flange arrangement  78  secured against a top surface of the manifold body  14  by screw fasteners  80 . Also, it can be seen that the manifold body  14  includes an upper cylindrical spray fluid inlet section  82  and a lower cylindrical spray fluid outlet section  84 , the sections  82  and  84  being clamped together by a plurality of bolt and nut combinations  86  arranged in a circular pattern. It is to be understood that, instead of the nut and bolt combinations  86 , the manifold body sections  82  may be secured together in any other suitable fashion including threaded or interlocking connections, for example. 
         [0026]    As can best be seen in  FIG. 3 , a central location of the inlet section  82  of the manifold body  14  is provided with a stepped cylindrical through bore  88 . The output shaft  54  of the stepper motor  52  is disposed along a central axis of the bore  88  and is connected to the nozzle selector disk  48  by a shaft coupler  90  having a blind bore  92  extending axially from an upper end of the coupler and receiving the output shaft  54 , with the coupler  90  being secured for rotation with the shaft  54  by being keyed or having a splined connection (not shown) in a well known manner and being axially secured by a setscrew  94 . A lower end section  96  of the shaft coupler has a non-round cross-section, which may be square or round with a flat, for example, received in a complementary shaped opening  98  located at the axial center of the disk  48 . The coupler  90  further includes an annular flange  100  engaging a top surface of the nozzle selector disk  48 . One or more shims  102  is (are) located on a top side of the flange  100  and takes up any space between a top surface  104  of an annular fluid chamber  106  defined by a circular recess formed in the bottom of the inlet section  82  and the top of the outlet section  84  of the manifold body  14 , the chamber  106  being in fluid communication with the spray fluid inlet  16  and extending over the top of the nozzle selector disk  48 . Leakage of spray fluid from the chamber  106  along a flat interface established between the inlet section  82  and the outlet section  84  of the manifold body  14  is prevented by an o-ring seal  108  located in an annular seal groove provided in the underside of the inlet section  82  outwardly of the chamber  106 . Leakage of fluid along an annular interface between the shaft coupler  90  and the surface of through bore  88  is prevented by a low friction, annular shaft seal  110  located in an annular seal receptacle  112  defined by the through bore  88 . An annular seal retainer plate  114  engages a top surface of the shaft seal  110  and is supported on an annular step surface  116  defined by through bore  88 . The retainer plate  114  is held in place by a snap ring  118  that is received in an annular snap ring groove provided in a surrounding wall region of the through bore  88 . Referring now also to  FIG. 4 , it can be seen that the bottom of the outlet section  84  of the manifold body  14  includes outlets  120 ,  122 ,  124  and  126 , respectively, axially aligned with the tubular nozzle connectors  24 ,  26 ,  28  and  30 . 
         [0027]    Referring now to  FIG. 5 , it can be seen that the outlet section  84  of the manifold  14  contains an arrangement of flow control slots. Considering a vertical line through the center of the plate to be the loci of a 0° position at the bottom of the outlet section  84  and a 180° position at the top of the section  84 , then, proceeding clockwise, first, second, third and fourth flow control slots  128 ,  130 ,  132  and  134 , respectively, are angularly spaced from each other about the axis of the outlet section  84  in an inner ring or circular arrangement of locations at 0°, 45°, 202.5° and 225°, while fifth, sixth, seventh and eighth flow control slots  136 ,  138  and  140 , respectively, are angularly spaced from each other in an outer ring or circular arrangement of locations at 0°, 90° and 180°. 
         [0028]    Referring now to  FIG. 6 , it can be seen that the nozzle selector disk  48  contains an arrangement of nozzle selector slots. Assuming that the disk  48  is rotated in a clockwise direction for sequencing between positions for effecting increasing spray rates from the spray head  12 , the position illustrated is that for preventing flow to all of the flow control slots of the outlet section  84 . In this zero flow or “off” position, first, second, third and fourth nozzle selector slots  142 ,  144 ,  146  and  148 , respectively, are angularly spaced counterclockwise from each other about the axis of the disk  48  in an inner ring of locations which lead the 0° location of the outlet section  84  of the manifold  14  by respective angles of 22.5°, 112.5°, 202.5° and 292.5°, while fifth, sixth, seventh and eighth nozzle selector slots  149 ,  150 ,  151  and  152 , respectively, are angularly spaced clockwise from each other in an outer ring of locations which lead the 0° location of the control plate  50  by respective angles of 90°, 112.5°, 135° and 157.5°. 
         [0029]    Referring now back to  FIG. 2  and also to  FIGS. 7 and 8 , it can be seen that the outlet section  84  of the manifold body  14  includes first, second, and third horizontal, parallel blind bores  154 ,  156  and  158 , respectively, extending horizontally from a right side, upper level region of the outlet section  84  and making right angles with a vertical plane P passing through the center of the section  84 , with the outlets  120  and  122  being located to one side of the plane P and with the outlets  124  and  126  being located on the other side of the plane P. As can best be seen in  FIG. 9 , the blind bores  154 ,  156  and  158 , respectively, have right end portions sealed by first, second and third threaded plugs  160 ,  162  and  164 , respectively. The blind bores  154 ,  156  and  158  intersect respective upper end regions of the spray fluid outlets  120 ,  122 , and  126  which each extend vertically in the lower section  84  of the manifold body  14 . A fourth horizontal blind bore  166  is also located in the upper level of the outlet section  84  of the manifold body  14 , the bore  166  intersecting an upper end region of the spray fluid outlet  124  and being oriented so as to intersect and traverse the plane P, with the bore  166  making an angle of approximately 45° with the plane P. A left end portion of the blind bore  166  is provided with a fourth threaded plug  168 . The blind bore  166  includes a reduced diameter section  170  beginning at a location between where the bore  166  intersects the flow control outlet  124  and the plane P resulting in an annular shoulder being formed which defines a valve seat  172  for a one-way check valve ball  174  having a purpose discussed below. Referring now also to  FIG. 10 , it can be seen that a fifth horizontal blind bore  176  is located at a second level in the lower manifold body section  84  which is below the first level in which the bores  154 ,  156 ,  158  and  166  are located, with the blind bore  176  being centered along the plane P, with an end region of the bore  176  being disposed vertically beneath an end region of the fourth bore  166  which traverses the plane P. As viewed in  FIG. 7 , a bottom end portion of the bore contains a threaded plug  178 . The bore  176  is stepped so as to have a reduced diameter upper end section  180  resulting in a shoulder which defines a valve seat  182  for a one-way check valve ball  184  having a purpose discussed below. 
         [0030]    As can best be seen in  FIGS. 7 ,  8  and  9 , of the four flow direction control slots  128 ,  130 ,  132  and  134  making up the inner ring of flow control slots of the outlet section  84 , the slots  128  and  130  are both in fluid communication with the blind bore  154 , and hence the outlet  120 , while the slots  132  and  134  are both in fluid communication with the blind bore  156 , and hence with the outlet  122 . The three flow control slots  136 ,  138  and  140 , which make up the outer ring of flow control slots, extend vertically in the outlet section  84 , with the slot  136  intersecting the blind bores  158  and  176 , the slot  138  intersecting the large diameter section of the blind bore  166 , and with the slot  140  intersecting the reduced diameter sections  170  and  180  respectively of the blind bores  166  and  176 . Thus, the slot  136  is in fluid communication with the outlet  126 , noting that the check ball  184  prevents flow to any other outlet, the slot  138  is connected in fluid communication with the outlet  124 , noting that the check ball  174  prevents flow to any other outlet, and the slot  140  is coupled in fluid communication with both outlets  124  and  126 , noting that the check ball  184  permits flow to the outlet  126  by way of the bore  176 , slot  136  and bore  158 . 
         [0031]    Referring now to  FIG. 11 , there is shown a table correlating sixteen selection positions of the nozzle selector disk  48  which are respectively attained by indexing the selector disk  48  clockwise through 22.5° increments from the 0 or “off” position shown in  FIG. 6 . Also listed is four nozzle spray rates of 1, 2, 4 and 8 gallons per minute (GPM) respectively produced by the four tips  40 ,  42 ,  44  and  46  of the nozzles  32 ,  34 ,  36  and  38  respectively receiving fluid from the four outlets  120 ,  122 ,  124  and  126 . A column is also provided indicating the sum of the outlet spray rates attained by each selector disk position, noting that the application rate in gallons per acre (GPA) for each selector disk position would depend upon the speed of travel of the sprayer vehicle. 
         [0032]    Accordingly, with the nozzle selector disk  48  in the 0 or “off” disk position the disk is in a disk angle of rotation of 0° wherein none of the flow direction control slots  128 - 140  at the top of the outlet section  84  of the manifold body  14  are selected, i.e., in alignment with any of the nozzle selection slots  142 - 152  of the selector disk  48 . Consequently, the sum of the nozzle flow rates when the selector disk  48  is in the “off” position is 0 gallons per minute (GPM). This relationship between the selector disk  48  and outlet section  84  is illustrated in  FIG. 12 . 
         [0033]    Position  1  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise relative to the outlet section  84  through an angle of 22.5° from the 0° position, to the position illustrated in  FIG. 13  wherein the selector slot  142  of the selector disk  48  is superposed over the flow control slot  128  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  128  is coupled in fluid communication with the outlet  120  that supplies fluid to the nozzle  32 , with the tip  40  of this nozzle having a spray rate of 1 GPM. 
         [0034]    Position  2  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 22.5° position, to a 45° position illustrated in  FIG. 14  wherein the selector slot  146  of the selector disk  48  is superposed over the flow control slot  132  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  132  is coupled in fluid communication with the outlet  122  that supplies fluid to the nozzle  34 , with the tip of this nozzle  42  having a spray rate of 2 GPM. 
         [0035]    Position  3  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 45° position, to a 67.5° position illustrated in  FIG. 15  wherein the selector slots  142  and  146  of the selector disk  48  are respectively superposed over the flow control slots  130  and  134  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  130  is coupled in fluid communication with the outlet  120  that supplies fluid to the nozzle  32 , this nozzle having the tip  40  having a spray rate of 1 GPM. The flow control slot  134  is coupled in fluid communication with the outlet  122  which is coupled to the nozzle  34 , with the tip  42  of this nozzle having a spray rate of 2 GPM. Thus, the sum of the spray rates from the spray head  12  is 3 GPM. 
         [0036]    Position  4  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 67.5° position, to a 90° position illustrated in  FIG. 16  wherein the selector slot  149  of the selector disk  48  is superposed over the flow control slot  136  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  136  is coupled in fluid communication with the outlet  126  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 4 GPM. Thus, the spray rate from the spray head  12  is 4 GPM. 
         [0037]    Position  5  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 90° position, to a 112.5° position illustrated in  FIG. 17  wherein the selector slots  144  and  150  of the selector disk  48  are respectively superposed over the flow control slots  128  and  136  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  128  is coupled in fluid communication with the outlet  120  that supplies fluid to the nozzle  32 , with the tip  40  of this nozzle having a spray rate of 1 GPM, and the control slot  136  is coupled in fluid communication with the outlet  126  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 4 GPM. Thus, the total spray rate from the spray head  12  is 5 GPM. 
         [0038]    Position  6  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 112.5° to a 135° position illustrated in  FIG. 18  wherein the selector slots  148  and  151  of the selector disk  48  are respectively superposed over the flow control slots  128  and  136  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  128  is coupled in fluid communication with the outlet  122  that supplies fluid to the nozzle  34 , with the tip  42  of this nozzle having a spray rate of 2 GPM, and the control slot  136  is coupled in fluid communication with the outlet  126  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 4 GPM. Thus, the total spray rate from the spray head  12  is 6 GPM. 
         [0039]    Position  7  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 135° position to a 157.5° position illustrated in  FIG. 19  wherein the selector slots  144 ,  148  and  152  of the selector disk  48  are respectively superposed over the flow control slots  130 ,  134  and  136  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  130  is coupled in fluid communication with the outlet  120  that supplies fluid to the nozzle  32 , with the tip  40  of this nozzle having a spray rate of 1 GPM. The flow control slot  134  is coupled in fluid communication with the outlet  122  that supplies fluid to the  34 , with the tip  42  of this nozzle having a spray rate of 2 GPM, and the control slot  136  is coupled in fluid communication with the outlet  126  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 4 GPM, and the control slot  136  is coupled in fluid communication with the outlet  126  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 4 GPM. Thus, the total spray rate from the spray head  12  is 7 GPM. 
         [0040]    Position  8  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 157.5° position to an 180° position illustrated in  FIG. 20  wherein the selector slot  149  of the selector disk  48  is superposed over the flow control slot  138  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  138  is coupled in fluid communication with the outlet  124  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 8 GPM. Thus, the total spray rate from the spray head  12  is 8 GPM. 
         [0041]    Position  9  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 180° position to a 202.5° position illustrated in  FIG. 21  wherein the selector slots  142  and  150  of the selector disk  48  are respectively superposed over the flow control slots  128  and  138  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  128  is coupled in fluid communication with the outlet  120  that supplies fluid to the nozzle  32  having the tip  40  which has a spray rate of 1 GPA, and the flow control slot  138  is coupled in fluid communication with the outlet  124  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 8 GPM. Thus, the total spray rate from the spray head  12  is 9 GPM. 
         [0042]    Position  10  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 202.5° position to a 225° position illustrated in  FIG. 22  wherein the selector slots  142  and  151  of the selector disk  48  are respectively superposed over the flow control slots  132  and  138  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  132  is coupled in fluid communication with the outlet  122  that supplies fluid to the nozzle  34  having the tip  42  which has a spray rate of 2 GPM, and the flow control slot  138  is coupled in fluid communication with the outlet  124  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 8 GPM. Thus, the total spray rate from the spray head  12  is 10 GPM. 
         [0043]    Position  11  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 225° position to a 247.5° position illustrated in  FIG. 23  wherein the selector slots  142  and  146  and  152  of the selector disk  48  are respectively superposed over the flow control slots  134 ,  130  and  138  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  134  is coupled in fluid communication with the outlet  122  that supplies fluid to the nozzle  34  having the tip  42  which has a spray rate of 2 GPM, the flow control slot  130  is in fluid communication with the outlet  120  that supplies fluid to the nozzle  32  having the tip  40  which has a spray rate of 1 GPM, and the  138  is coupled in fluid communication with the outlet  124  that supplies fluid to the nozzle  38 , with the tip  46  of this nozzle having a spray rate of 8 GPM. Thus, the total spray rate from the spray head  12  is 11 GPM. 
         [0044]    Position  12  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 247.5° position to a 270° position illustrated in  FIG. 24  wherein the selector slot  149  of the selector disk  48  is superposed over the flow control slot  140  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  140  is coupled in fluid communication with both outlets  124  and  126 , these outlets respectively supplying fluid to the nozzles  36  and  38 . The nozzle  36  has the spray tip  44  having the spray rate of 8 GPM, and the nozzle  38  has the spray tip  46  respectively having the spray rate of 4 GPM. Thus, the total spray rate from the spray head  12  is 12 GPM. 
         [0045]    Position  13  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 270° position to a 292.4° position illustrated in  FIG. 25  wherein the selector slots  148  and  150  of the selector disk  48  are respectively superposed over the flow control slots  128  and  140  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  128  is coupled in fluid communication with the outlet  120  which supplies fluid to the nozzle  32  having the spray tip  40  having the spray rate of 1 GPM. The flow control slot  140  is connected in fluid communication with both of the outlets  126  and  124 , with the outlet  126  supplying fluid to the nozzle  38  having the tip  46  which has the spray rate of 4 GPM and with the outlet  124  supplying fluid to the nozzle  36  having the tip  44  which has the spray rate of 8 GPM. Thus, the total spray rate from the spray head is 13 GPM. 
         [0046]    Position  14  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 292.5° position to a 215° position illustrated in  FIG. 26  wherein the selector slots  144  and  151  of the selector disk  48  are respectively superposed over the flow control slots  132  and  140  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  132  is coupled in fluid communication with the outlet  122  which supplies fluid to the nozzle  34  having the spray tip  42  having the spray rate of 2 GPM. The flow control slot  140  is connected in fluid communication with both of the outlets  126  and  124 , with the outlet  126  supplying fluid to the nozzle  38  having the tip  46  which has the spray rate of 4 GPM and with the outlet  124  supplying fluid to the nozzle  36  having the tip  44  which has the spray rate of 8 GPM. Thus, the total spray rate from the spray head is 14 GPM. 
         [0047]    Position  15  of the selector disk  48  is achieved by indexing the selector disk  48  clockwise through an angle of 22.5° from the 215° position to a 237.5° position illustrated in  FIG. 27  wherein the selector slots  144 ,  148  and  152  of the selector disk  48  are respectively superposed over the flow control slots  130 ,  134  and  140  of the outlet section  84  of the manifold body  14 . As described above, the flow control slot  130  is coupled in fluid communication with the outlet  120  which supplies fluid to the nozzle  32  having the spray tip  40  having the spray rate of 1 GPM. The flow control slot  134  is connected in fluid communication with the outlet  122  which supplies fluid to the nozzle  34  having the spray tip  42  which has a spray rate of 2 GPM. The flow control slot  140  is connected in fluid communication with both of the outlets  126  and  124 , with the outlet  126  supplying fluid to the nozzle  38  having the tip  46  which has the spray rate of 4 GPM and with the outlet  124  supplying fluid to the nozzle  36  having the tip  44  which has the spray rate of 8 GPM. Thus, the total spray rate from the spray head is 15 GPM. 
         [0048]    It is to be understood that, while the nozzle selector disk  48  and flow direction control plate  50  are particularly suited for making it possible to sequentially select different ones or different combinations of the nozzles  32 - 38  for effecting eleven ever increasing spray rates, other selector disk control slot arrangements and outlet arrangements could be designed which would operate in accordance with the principles of the present invention to achieve satisfactory results for some spraying applications. Additionally, it is to be understood that, for some spray application rates, it might be expedient to provide selector disk control slot arrangements and outlet arrangements requiring the selector disk to be moved other tan sequentially among the “on” positions of the selector disk, even requiring the drive motor  52  to be reversed at times. 
         [0049]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.