Abstract:
A milking apparatus that is used to extract milk from dairy animals includes a vacuum source, a milking liner cooperating with a shell to define a pulsation chamber; and a pulsator in fluid communication with the pulsation chamber and the vacuum source. The pulsator is configured to produce at least a four-phase milking cycle in the milking liner with the cycle including at least an A phase and a C phase. The A phase is wherein the liner is changed from a closed configuration to an open configuration during which the pulsator provides fluid communication between the pulsation chamber and the vacuum source. The C phase is wherein the liner is changed from an open configuration to a closed configuration during which the pulsator allows atmospheric air to flow into the pulsation chamber. A restrictor is disposed in the path of the fluid communication between the pulsator and the pulsation chamber with the restrictor slowing the C phase compared to the A phase.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/974,455 filed Sep. 22, 2007; the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention generally relates to automated milking apparatus and, more particularly, to a restrictor for controlling the “A” phase or the “C” phase of the pulsation process. Specifically, the invention relates to a restrictor that may be incorporated into the pulsation process to slow the “C” phase of the pulsation process to improve milking efficiency. One manner of positioning the restrictor is to splice the restrictor into the pulsator tube. 
     2. Background Information 
     An example of an automated milking machine is indicated generally by the numeral  1  in  FIG. 1 . Machine  1  is one example of a configuration known in the art to extractor milk from dairy animals. Milk extraction typically occurs in a milking facility where dairy animals are positioned in milking stalls. Milking machine  1  may be provided for each milking stall. Machine  1  generally includes a claw  2 , multiple teatcups  3 , a long milk tube  4 , a long pulsator tube  5 , and a pulsator  6 . Claw  2  is an assembly that connects short pulsator tubes  7  and short milk tubes  8  from teatcups  3  to long pulsator tube  5  and long milk tube  4 . A milk bucket  9  is provided to accumulate the milk extracted from the animal. A vacuum source  10  is fluid communication with machine  1 . 
     As shown in  FIG. 2 , each teatcup  3  includes a rigid outer shell  11  that holds a soft milking liner or inflation  12 . The annular space between shell  11  and liner  12  is a pulse or pulsation chamber  13 . Liners  12  are attached to the teats  14  of a dairy animal to perform the milking process. The milking process is driven by applying a cyclic vacuum to pulsation chamber  13 . 
     During milking, liner  12  is subjected to a milking vacuum  15  through short milk tube  8 .  FIG. 3  depicts the following pulsation process graphically. Pulsation chamber  13  is subjected to a pulsating vacuum that varies between approximate atmospheric pressure and a vacuum pressure that approximates or is greater than the milking vacuum applied to liner  12 . The pulsating vacuum is controlled by pulsator  6 . Pulsator  6  has a four-phase pulsation cycle defined by (i) an opening phase (the A phase) during which the pulsation vacuum  16  increases from atmospheric pressure to the milking vacuum level and liner  12  moves from a closed position to an open position (the pressure of liner  12  is indicated on the graph with reference line  17 ), (ii) an open phase (the B phase) during which the pulsating vacuum has reached its maximum level, which is substantially equal to the milking vacuum level, liner  12  is in an open position allowing milk to flow from teat  14 , (iii) a closing phase (the C phase) during which the pulsating vacuum decreases from about the milking vacuum level to the atmospheric pressure and liner  12  moves from the open position to the closed position, and (iv) a closed phase (the D phase) during which the pulsating vacuum is equal to the atmospheric pressure and inflation  12  is in a closed position stopping milk flow from teat  14 . The above action of pulsator  6  is referred to herein generally as the “pulsation process.” The above phases are referred to as phase A, phase B, phase C, and phase D. 
     As shown in  FIG. 2 , pulsator  6  applies the different vacuum pressures of phases A-D to chamber  13  through a long pulsator tube  5  and a short pulsator tube  7 . Tubes  5  and  7  are typically flexible tubing. 
     SUMMARY OF THE INVENTION 
     The invention provides an apparatus that restricts at least one of the phases of the pulsation process. In one configuration, the apparatus slows the C phase. The restriction may be adjustable. 
     The restrictor of the invention may be placed, by splicing or by using a pair of pulsator tubes, along the short, long, or both pulsator tubes. The restrictor slows the flow of atmospheric air back into the pulsation chamber thus slowing the C phase of the pulsation process. Slowing the C phase is believed to provide more efficient milking by decreasing the overall time required to extract milk. 
     The invention also provides a restrictor that may be used to slow the A phase by reversing the orientation of the restrictor along the short, long, or both pulsator tubes. 
     In one configuration, the invention provides a pulsator flow restrictor for a pulsator tube in an automated milking apparatus. The restrictor includes a restrictor body defining a main airflow pathway and an alternate airflow pathway; a check valve disposed in the main airflow pathway; and the alternate air pathway bypassing the check valve; the alternate airflow pathway having a lower flow rate than the main airflow pathway. 
     The invention provides a milking apparatus having: a vacuum source; a milking liner cooperating with a shell to define a pulsation chamber; a pulsator in fluid communication with the pulsation chamber and the vacuum source; the pulsator configured to produce at least a four-phase milking cycle in the milking liner; the cycle including at least an A phase and a C phase; the A phase being wherein the liner is changed from a closed configuration to an open configuration during which the pulsator provides fluid communication between the pulsation chamber and the vacuum source; the C phase being wherein the liner is changed from an open configuration to a closed configuration during which the pulsator allows atmospheric air to flow into the pulsation chamber; and a restrictor disposed in the path of the fluid communication between the pulsator and the pulsation chamber; the restrictor slowing the C phase compared to the A phase. The restrictor may have a main airflow pathway and an alternate airflow pathway; the flow rate through the alternate airflow pathway being slower than the flow rate through the main airflow pathway; the atmospheric air flowing into the pulsation chamber during the C phase being directed through the alternate airflow pathway. 
     In one configuration, the restrictor includes a body defining a main air pathway running from the inlet to the outlet. A check valve is mounted in the main air pathway. The check valve is to be open during the A phase and closed during the C phase of pulsation. The body of the restrictor also defines an alternate airflow pathway, which allows both vacuum and atmospheric air to pass through. In one configuration, the serpentine configuration of the alternate pathway slows the flow. In another configuration, the cross sectional area of the alternate airflow pathway is reduced compared to the cross sectional area of the main air pathway and thus reduces the flow. Another configuration uses an impediment such as a valve to reduce the flow. These configurations may be used alone or in combination to control the C phase flow. The flow rates may be adjustable. 
     Another configuration of the invention uses a bi-directional valve in the main airflow path. The bi-directional valve is configured to allow air to flow faster in one direction than the other. The flow rates may be adjustable. 
     A further configuration of the restrictor adjusts the flow rate by providing a body having first and second portions that receive the check valve. The first and second portions may be rotated with respect to each other to adjust the cross sectional area of the flow path. Indicators on the body portions may be provided to show the flow rate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a portion of a prior art milking machine. 
         FIG. 2  is a schematic view of a portion of a prior art milking machine attached to a teat. 
         FIG. 3  is a graphical representation of the pulsation process. 
         FIGS. 4-7  depict a first exemplary configuration of the restrictor. 
         FIG. 4A  is a perspective view of the first configuration of the restrictor. 
         FIG. 4B  is an exploded perspective view of the first configuration of the restrictor. 
         FIG. 5A  is a perspective view of the rear end of the first body portion of the first configuration. 
         FIG. 5B  is a section view taken along line  5 B- 5 B of  FIG. 4A . 
         FIG. 5C  is a section view taken along line  5 C- 5 C of  FIG. 5B . 
         FIG. 5D  is a section view taken along line  5 D- 5 D of  FIG. 5C . 
         FIG. 6A  is a section view taken along line  6 A- 6 A of  FIG. 5C . 
         FIG. 6B  is a perspective view of the front end of the first body portion. 
         FIG. 6C  is a section view taken along line  6 B- 6 B of  FIG. 4A . 
         FIG. 7A  is a section view taken along line  7 A- 7 A of  FIG. 4B . 
         FIG. 7B  is a section view taken along line  7 B- 7 B of  FIG. 7A . 
         FIG. 7C  is a perspective view looking into the second body portion. 
         FIG. 7D  is a side view of the second body portion. 
         FIGS. 8-11  depict a second exemplary configuration of the restrictor. 
         FIG. 8A  is a perspective view of the second configuration of the restrictor. 
         FIG. 8B  is an exploded perspective view of the second configuration of the restrictor. 
         FIG. 9A  is a perspective view of the rear end of the first body portion of the second configuration 
         FIG. 9B  is a section view taken along line  9 B- 9 B of  FIG. 8A . 
         FIG. 9C  is a section view taken along line  9 C- 9 C of  FIG. 9B . 
         FIG. 10A  is a side view of the first body portion of the second configuration. 
         FIG. 10B  is a perspective view of the first end of the first body portion. 
         FIG. 10C  is a section view taken along line  10 C- 10 C of  FIG. 10A . 
         FIG. 11A  is a perspective view looking into the second body portion. 
         FIG. 11B  is an end view of the second body portion. 
         FIG. 11C  is a section view taken along line  11 C- 11 C of  FIG. 11B . 
         FIGS. 12-15  depict a third exemplary configuration of the restrictor. 
         FIG. 12A  is a perspective view of the third configuration of the restrictor. 
         FIG. 12B  is an exploded perspective view of the third configuration of the restrictor. 
         FIG. 13A  is a perspective view of the second end of the valve. 
         FIG. 13B  is a section view taken along line  13 B- 13 B of  FIG. 12  A. 
         FIG. 13C  is a section view taken along line  13 C- 13 C of  FIG. 13B . 
         FIG. 14A  is a perspective view of the first end of the first body portion of the third configuration. 
         FIG. 14B  is a side view of the first body portion. 
         FIG. 14C  is a section view taken along line  14 C- 14 C of  FIG. 14B . 
         FIG. 15A  is a perspective view looking into the second body portion of the third configuration. 
         FIG. 15B  is an end view of the second body portion. 
         FIG. 15C  is a section view taken along line  15 C- 15 C of  FIG. 15B . 
         FIG. 15D  is an enlarged view of the encircled portion of  FIG. 15C . 
         FIGS. 16-20  depict a fourth exemplary configuration of the restrictor. 
         FIG. 16A  is a perspective view of the fourth configuration of the restrictor. 
         FIG. 16B  is an exploded perspective view of the fourth configuration of the restrictor. 
         FIG. 17A  is section view taken along line  17 A- 17 A of  FIG. 16A . 
         FIG. 17B  is a perspective view of the second end of the valve. 
         FIG. 17C  is a section view taken along line  17 C- 17 C of  FIG. 17A . 
         FIG. 18A  is an end view of the first body portion. 
         FIG. 18B  is a side view of the first body portion. 
         FIG. 18C  is a section view taken along line  18 C- 18 C of  FIG. 18B . 
         FIG. 19A  is a perspective view looking into the second body portion of the fourth configuration of the restrictor. 
         FIG. 19B  is a side view of the second body portion. 
         FIG. 19C  is an end view of the second body portion. 
         FIG. 19D  is a section view taken along line  19 D- 19 D of  FIG. 19C . 
         FIG. 19E  is a section view taken along line  19 E- 19 E of  FIG. 19B . 
         FIG. 20  depicts different flow adjustments for the fourth configuration of the restrictor. 
         FIGS. 21-24  depict a fifth exemplary configuration of the restrictor. 
         FIG. 21A  is a perspective view of the fifth configuration of the restrictor. 
         FIG. 21B  is an exploded perspective view of the fifth configuration of the restrictor. 
         FIG. 22A  is a perspective view of the second end of the valve. 
         FIG. 22B  is section view taken along line  22 B- 22 B of  FIG. 21A . 
         FIG. 22C  is a section view taken along line  22 C- 22 C of  FIG. 22B . 
         FIG. 23A  is a side view of the first body portion. 
         FIG. 23B  is a section view taken along line  23 B- 23 B of  FIG. 23A . 
         FIG. 24A  is a side view of the second body portion of the fifth configuration of the restrictor. 
         FIG. 24B  is a section view taken along line  24 B- 24 B of  FIG. 24A . 
         FIG. 24C  is a section view taken along line  24 C- 24 C of  FIG. 24A . 
         FIG. 25  is a side view of a sixth exemplary configuration of the restrictor. 
         FIG. 26  is a perspective view of the sixth configuration. 
         FIG. 27  is an exploded perspective view of a seventh exemplary configuration of the restrictor. 
         FIG. 28  is a perspective view of the seventh configuration. 
     
    
    
     Similar numbers refer to similar, but not necessarily identical, parts throughout the specification. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The restrictor configurations of the invention allow the speed of the A and C phases of the pulsation process to be changed. The amount of the change can be determined by using a tool that measures air pressure over time. The results of such a measurement can be presented in a graph such as that shown in  FIG. 3  wherein the A-D phases are graphically represented. These phases are also commonly referred to the opening and closing of liner  12 . The A phase is the opening of liner  12 , the B phase is when liner  12  is open and is called the “milking phase”, the C phase is the closing of liner  12 , and the D phase is when liner  12  is closed and is called the “rest phase”. The restrictor of the invention may be used to change the “C” phase (atmospheric air entering chamber), while not substantially changing the “A” phase (vacuum in the chamber). When used to change the “C” phase, an alternate airflow pathway or a plurality of alternate airflow pathways are provided by the restrictor of the invention to determine the speed of the “C” phase. This is accomplished by changing the size, shape, length, or number (or a combination of all) of the alternate airflow pathway or pathways. 
     A typical use of the restrictor is to alter the C phase by lengthening the C phase and shortening the D phase while not substantially changing the A and B phases. An alternative use is to alter the A phase by lengthening the A phase while shortening the B phase while not substantially changing the C and D phases. Lengthening the C phase is believed to increase milking efficiency by decreasing the time required to extract milk. 
       FIGS. 4-24  depict the construction and assembly of exemplary pulsator restrictor configurations. In each of the configurations of  FIGS. 4-24 , the reference numeral  20  is used to generally indicate a restrictor having a first body portion  22  and a second body portion  24  that connect together to define a main airflow pathway  26  and at least one alternate airflow pathway  28  with a check valve  30  disposed in at least main airflow pathway  26 . In one configuration, valve  30  is a bi-directional valve that allows less air flow in one direction than the other. When valve  30  is configured to be bi-directional, the alternate airflow pathways described below are not necessarily needed for restrictor  20  to function as the reduced air flow rate back through valve  30  is enough to slow the A or C phase as desired. In another configuration, valve  30  allows air to flow substantially freely in the direction from its base towards its taper while permitting little or no airflow in the other direction. When valve  30  is configured in this manner, the air flow back through valve is directed through the alternate airflow pathway or pathways described below to achieve the desired slowing. Valve  30  is formed from a flexible and resilient material that substantially seals against the surfaces of the body portions. Valve  30  may include one or more raised rings  32  that engage the inner portion of first body portion  22  to form a good seal. Valve  30  may also include a flange  34  at its base that fits tightly within a recess  36  defined by first body portion  22  such that the end of flange  34  engages the inner surface  110  of second body portion  24 . The configurations of  FIGS. 4-24  allow the alternate airflow pathway  28  to be adjusted by rotating body portions  22  and  24  with respect to each other. Each body portion  22  and  24  is configured to be readily attached to a flexible tube of the sort typically used as a pulsator tube  5  or  7 . As such, each body portion  22  and  24  may have a tube-shape end adapted to fit over or inside a pulsator tube  5  or  7 . 
     In each of the configurations of  FIGS. 4-24 , first body portion  22  includes a pair of cantilevered, resilient arms  40  that are received in a snap-fit connection into a portion of second body portion  24 . Arms  40  hold body portions  22  and  24  together with valve  30  trapped inside aligned main airflow pathway  28 . The position of arms  40  may be reversed so that arms  40  cantilever from second body portion  24 . Each arm  40  includes a hand  41  having a catch surface that cooperates with a corresponding catch surface defined by second body portion  24 . Each hand  41  also defines an angled wall that engages a portion of second body portion  24  when body portions  22  and  24  are brought together to force arms  40  outwardly. An external band  43  (shown in  FIGS. 21 and 22 ) may be used to hold arms  40  of any configuration in place after they have engaged second body portion  24 . In the fifth exemplary configuration, each arm defines has a band loop  45  that defines an opening configured to receive band  43  to hold band  43  on arms  40 . Band  43  may be a toothed strap that locks to itself in a manner similar to a plastic wire tie. 
     In the first and second configurations of restrictor  20 , second body portion  24  defines spaced slots  42 . In these configurations, the catch surface of arms  40  engages an edge wall that defines slots  42 . Aggressive rotation of body portions  22  and  24  may snap arms  40  out of slots  42  and allow free rotation of first and second body portions  22  and  24  with respect to each other. Body portions  22  and  24  may be rotated with respect to each other while they are seated (one body portion inside the other) together. The relative angular position of the first  22  and second  24  body portions defines the flow rate through alternate airflow pathway  28 . Indicators  44  are used to show the user which flow rate is selected. Indicators  44  may be numbered or provided in different sizes that relate to the flow rate. In the first and second configurations of  FIGS. 4-11 , first body portion  22  defines a plurality of alternate airflow pathways  100 ,  102 ,  104 , and  106  (See  FIGS. 6 and 10 ) having different cross sectional areas. Body portions  22  and  24  are rotated to change the angular position of the body portions to open only one or a selected combination of pathways  100 - 106  to alter the cross section of alternate airflow pathway. Inner face  110  of second body portion  24  seals the three pathways that are not selected for use. In the first configuration, inner surface is configured to allow different combinations of pathways to be selected. In the second configuration, surface  110  defines a single recess  112  that open one pathway  100 - 106  as each rotated into alignment with recess  112 . 
     In the third-fifth configurations of restrictor  20 , the catch surface of arms  40  engages an edge wall that defines a continuous slot  42 . In these configurations, a protruding indicator knob  44  is received in one of a series of spaced cutouts  46  defined about the circumference of second body portion  24  to lock the position of the first body portion  22  with respect to the second body portion  24 . The positions of knob  44  and cutouts  46  may be reserved such that knob  44  extends from second body portion  24  with first body portion  22  defining cutouts  46 . The engagement of indicator knob  44  in slot cutout  46  prevents the first and second body portions from rotating with respect to each other about their longitudinal axis. Body portions  22  and  24  are configured to allow knob  44  to be slid out of cutout  46  without completely unseating portions  22  and  24 . The relative position of the first and second body portions  22  and  24  defines the flow rate through alternate airflow pathway  28 . 
     In the configurations of  FIGS. 12-24 , valve  30  includes a flange  120  that extends in a direction substantially perpendicular to the longitudinal axis of valve  30  and extends over at least a portion of the end of first body portion  22 . Flange  120  defines a plurality of notches  122  (may be notch holes  122  as shown in  FIG. 12B ) that define a portion of alternate airflow pathway  28 . The relative position of body portions  22  and  24  defines the percentage of blockage for passageway  28  as shown, for example, in  FIG. 20 . Cutouts  46  are positioned at different angles about body portion  24  so that the engagement of knob  44  with each cutout  46  provides a different percentage of blockage for alternate passageway  28 . 
     Body portion  22  defines at least one channel  124  but may define a plurality of channels  124  such as the four channels shown in the drawings. Each channels  124  runs along valve  30  and may be used as a portion of alternate airflow passageway  28 . The number of notches  122  in flange  120  defines the number of channels  124  that are used as part of alternate passageway  28 . Although four notches  122  are show in the drawings, valve  30  may be provided with 1-4 notches  122 . When a notch  122  is defined for each channel  124 , each channel  124  may be used. In some configurations, the number of notches  122  in flange  120  may be less than the number of channels  124 . Reducing the number of notches  122  allows restrictor to be tuned to different flow rates simply by replacing valve  30 . Second body portion  24  defines elbows  126  that form a portion of passageway  28  when they are aligned with notches  122 . 
     The position of flange  120  is fixed with respect to first body portion  22  with notches  122  in at least partial alignment with channels  124 . A peg  128  may be received by a recess or opening  129  in flange  120  to fix the position of valve  30  with respect to first body  22 . As explained above, body portions  22  and  24  may be rotated with respect to each other to different angular relationships defined by knob  44  and cutouts  46 . Each different angular relationship changes the position of flange  120  with respect to elbows  126  to block a different percentage of elbows  126 . Each different angular relationship thus changes the cross section of passageway  28  and thus changes the flow rate through passageway  28 .  FIG. 20  shows an example of how the different angular positions of body portions  22  and  24  define different cross sections for passageway  28 . 
       FIGS. 25-26  and  27 - 28  depict other exemplary configurations for the restrictor. The configuration of  FIGS. 25-26  uses an alternate airflow pathway  124  that is defined through the body of body portion  22  separate from the primary airflow pathway that receives valve  30 . Alternate airflow pathway  30  has a smaller cross sectional area than the main airflow pathway. The configuration of  FIGS. 27-28  uses a block having two halves that define a main airflow pathway and an alternate airflow pathway that is serpentine. A valve  30  may be placed in the main airflow pathway. The serpentine nature of the alternate airflow pathway slows the air flow rate back through restrictor  20 . The cross sectional area of the alternate airflow pathway also slows the flow. 
     In one experiment, the C phase timing was tested at 90 milliseconds, 120 milliseconds, and 150 milliseconds. The 150 millisecond test compared to the 90 millisecond test showed an increased peak flow rate of the milk of over 7 percent with an increased average flow rate of 4.97 percent. This test used the Lauren Tri-Circle® silicone liner with vacuum levels of 12, 14, and 15 in HG over an 18 day period. Milk yield was measured over the first two minutes of milking with a fixed pulsator rate of 60 cpm and a fixed pulsator ratio of 65:35. The test shows that the liner closes fast at 90 millisecond and slows the milking rates compared to the 120 millisecond and 150 millisecond rates. 
     In view of the foregoing, one of ordinary skill in the art will understand that the flow restrictors described above and in the drawings may be used to control the flow of air back into the pulsation chamber to slow the C phase of the pulsation process. Controlling the C phase of the milking cycle is believed to increase milking performance by providing faster milking times while harvesting the same volume of milk as in prior art systems. The restrictors may be reversed to limit vacuum flow from the chamber to control the A phase. Certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
     Moreover, the description and illustration of the invention are exemplary and the invention is not limited to the exact details shown or described.