Abstract:
A milk machine detaching mechanism suitable for use in a sloping splash panel or other vertically limited space, having a pair of opposing components that can transfer load in the vertical direction, but which slide relative to one another in a lateral direction. The detacher is capable raising a milk machine support arm in a smooth and arc-shaped direction to avoid contact with a cow or a cow support platform as the support arm is being withdrawn. The detacher includes a folding arm assembly to minimize potential pinch points.

Description:
This application is a continuation of application Ser. No. 09/059,553 filed Apr. 13, 1998, now U.S. Pat. No. 5,960,537, the disclosure of which is incorporated by referenced herein. 
    
    
     FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates generally to milking machine detacher mechanisms and particularly to an automatic milking machine detacher mechanism useful for being mounted in a sloping splash shield or other space-constrained location. 
     Automatic arm detachers for milking machines have been in use for many years. Typically, the detacher mechanism is mounted on a wall or a rail adjacent to the milking machine or is mounted inside a vertical splash shield to save space and maintain the cleanliness of the mechanism. 
     When the detacher mechanism is mounted inside of a cabinet or splash shield the mechanism includes a pneumatic cylinder, a chain, pulleys, and a counterweight that moves vertically as the detacher mechanism retracts the milking machine. Due to the length of the milking machine support arm and the distance between the detacher mechanism and the milking stall, the distance of vertical movement by the pneumatic cylinder piston and the counterweight is considerable. Where space is not a concern, such as in vertically oriented panels or splash shields, the traditional detacher arrangement is useful and dependable. When, however, vertical space is at a premium the traditional mechanism is not practical and will not work dependably. 
     Thus, there is needed a detacher mechanism for a milking machine that can be used in a sloping splash shield or other space that does not permit large vertical movement of mechanism components. 
     SUMMARY OF THE INVENTION 
     A milking machine detacher in accordance with the present invention includes: a reciprocating piston that reciprocates in response to the action of a pneumatic cylinder or similar mechanism; a first clevis fixed to the reciprocating piston; a first chain having a first end fixed to the reciprocating piston and a second end; an articulated milker arm joined to the second end of the chain; a milker arm support joined to the articulated milker arm; a second clevis joined to the milker arm support and arranged to be engaged by the first clevis; a second chain having a first end connected to the milker arm support and a second end; and a counterweight joined to the second end of the second chain. 
     The milking machine detacher may further include: a sloped splash panel in which the piston, the first clevis, the second clevis are mounted, and the counterweight are mounted. The milking machine detacher milker arm support may include a tapered upper end for reducing necessary clearance within the sloped splash panel. 
     The milking machine detacher may further include an automatic controller for operating the piston, such as a programmable logic controller on a milking machine. The first clevis and the second clevis are preferably disengaged when the detacher is at a fully extended position, engaged during a detacher retracting movement; and disengaged at a detacher retracted position to provide an arc-shaped movement of the milker arm and avoid dragging a milking machine on the cow platform. 
     The milking machine detacher preferably includes a first roller fixed to the reciprocating piston and in sliding contact with the first chain; and a second roller fixed against vertical movement and in sliding contact with the first chain so that the chain will be retracted a distance greater that the distance the reciprocating piston. Further, the first clevis preferably includes a longitudinal horizontal axis, and the second clevis includes a longitudinal horizontal axis orientated at an angle to the horizontal axis of the first clevis so that the devises can transfer vertical load, but will slide relative to one another as the first clevis moves laterally during the retracting motion. 
     These and other features and benefits are described in detail below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial plan view of a herringbone milking parlor with sloped splash shields in accordance with the present invention. 
     FIG. 2 is a perspective view of a sloping splash shield with an automatic arm detacher in the fully extended position in accordance with the present invention. 
     FIG. 3 is a perspective view of the automatic milking machine arm detacher in a retracting position. 
     FIG. 4 is a perspective view of the automatic milking machine arm detacher in a fully retracted position. 
     FIG. 5 a  is a partial side view of the detacher mechanism in the fully extended position. 
     FIG. 5 b  is a partial side view of the detacher chain at the start of the detaching motion. 
     FIG. 6 a  is a partial side view of the detacher mechanism partially through the detaching motion. 
     FIG. 6 b  is a partial side view of the detacher chain partially through the detaching motion. 
     FIG. 7 a  is a partial side view of the detacher mechanism in the retracted position. 
     FIG. 7 b  is a side view of the detacher chain in the retracted position. 
     FIG. 8 is a partial exploded view of an arm assembly in accordance with the present invention. 
     FIG. 9 is a plan view of the arm assembly partially folded. 
     FIG. 10 is a plan view of the arm assembly completely folded. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following detailed description of the drawings, the same reference numerals will be used for the same or similar item in each of the figures. Illustrated in FIG.  1  and referred to generally by  20  is an automatic milker arm detacher in accordance with the present invention. The detacher  20  is mounted inside a sloped splash panel  22 . 
     The sloped splash panel  22  is positioned near the rear of milking stalls  28  that are arranged in a herringbone pattern. Such a stall pattern is a space-efficient arrangement that optimizes dairy parlor space, but presents severe space constraints for personnel and equipment. One way to accommodate a herringbone stall arrangement is to use sloped splash panels  22  which provide a back-stop for the cows  16  and protect the milker operator  18 . Typically, splash panels are oriented vertically and can be used to contain an automatic detacher which has components that move vertically within the splash panel to retract a milker and milker support arm. When a sloped splash panel is used, there is insufficient vertical space for a traditional automatic detacher. 
     Thus, the detacher in accordance with the present invention is a space-saving design that can be used in a sloped splash panel  22  or anywhere space is at a premium. Of course, such a design can be also be used in an open area, but the sloped splash shield design benefits most with the present invention. 
     FIGS. 2 to  4  illustrate that the detacher  20  is contained almost entirely within sloped splash panel  22  and hinged access door  24 . The sloped splash panel  22  is at an acute angle relative to vertical and at least 11 degrees which is the angle at which traditional vertical detacher mechanisms fail to work reliably. The detacher  20  includes: pneumatic or electronic controls  36 ; a pneumatic\electronic controller  38  in communication with the pneumatic or electronic controls  36 ; a pair of hoses  40  and  41  in communication with the pneumatic controller  38 ; and a pneumatic cylinder  42  that includes a reciprocating shaft or piston  44 . The pneumatic or electronic controls  36  can be either manual switches, programmable switches, or electronic relays from a remote electronic controller such as a milk meter that activates the detacher  20  at the completion of cow milking. 
     The pneumatic or electronic controls  36  activate the pneumatic\electronic controller  38  with a suitable pneumatic or electronic signal transmitted through hoses or wires  48 . The pneumatic\electronic controller  38  feeds air to the pneumatic cylinder  42  via hose  40  and hose elbow  50 . The pneumatic controller  38  releases air via hose  41  and a quick exhaust valve  52 . When air is fed to the pneumatic cylinder  42 , the piston  44  moves out of the cylinder  42  and downward. Conversely, when air is exhausted from the pneumatic cylinder  42  the piston  44  is retracted upward and into the cylinder. The piston  44  reciprocates along the same acute angle of the sloped splash panel  22 . Although the pneumatic cylinder is preferred, other lifters such as hydraulic cylinders for example, may be used. Further, the reciprocating member can be a rod, shaft, pipe, tube and all are included within the term “piston,” as used herein. 
     At the lower end of the piston  44  is a first clevis  58  which is formed from a cylindrical rod joined at one end to the piston  44  and having a hooked outer end. The first clevis  58  includes an elongated central portion having a longitudinal horizontal axis for engaging a second clevis  60  which is also formed from a cylindrical rod and includes a central longitudinal horizontal axis and a hooked outer end. Although depicted as cylindrical, the first clevis  58  and the second clevis  60  need not be cylindrical, but can be other shapes as well, so long as the two devises can transmit the vertical loads of the detacher  20  while sliding laterally relative to one another as described below. Thus, the term “clevis” includes bent cylindrical rods as illustrated, and other devices that transmit vertical, but not lateral loads during the retracting motion. The hook ends are merely provided to prevent the clevises from slipping off one another and not to carry loads during the retracting motion. 
     Also connected to the lower end of the piston  44  is a first chain  64  which extends downward, under a first roller  65  rotatably joined to the panel  22 , over a second roller  66  rotatably joined to the piston  44  via a bracket  67 , and through a hole in the splash panel  22 . The rollers  65  and  66  interact to draw the first chain  64  upward an amount greater than the distance of movement by the piston. 
     The hole includes a bushing  68  that guides the chain  64  and prevents excessive rubbing. The first chain  64  extends farther downward into an arm assembly  70 . Although depicted and described as a chain having metal links, the chain can be a rope, cord, wire or other means of transferring tension between the piston  44  and the arm assembly  70 . 
     The arm assembly  70  includes: an arm support plate  72 ; a large arm segment  74 ; a medium arm segment  76 ; and a small arm segment  78  that are all connected to one another with hinges  80  using appropriate bushings for smooth and dependable movement of the arm assembly  70 . Although depicted in gradually decreasing size, the arm assembly segments can be the same size, increasing size, random size or even include additional arm segment components depending upon the degree of articulation desired. 
     The arm segments  74 ,  76 ,  78  are preferably made using a cylindrical rod perimeter material  82  welded to the perimeter of an interior plate  84 . The cylindrical rod  82  and interior plate  84  provide smooth, strong surfaces to protect both cow and operator. Further, to relieve possible pinch points, the rounded surfaces of the hinge  80  and cylindrical rod  82  are positioned within very close proximity to eliminate a pinch point along the axis of the hinge. The chain bushings  88  extend well through the arm segments  74 ,  76 ,  78  to provide horizontal spacing between each arm segment which also eliminates pinch points as discussed in detail below. 
     The first chain  64  engages the arm assembly  70  first through a bushing  86  in the top of the arm support plate  72  and then through three holes in the arm segments which include retaining rings and bushing assemblies  88  to reduce friction as the chain is pulled to retract the arm assembly  70 . The end of the first chain  64  is secured on the back of the small arm segment  78  using any suitable stop mechanism  117  in FIG.  4 . The arm assembly  70  may include additional components such as a hose hook  90  and a snap lock  92  suspended by a chain  94  to suspend the milking machine and hoses (not illustrated) from the arm assembly  70 . Finally, the arm assembly  70  includes a sleeve and spring assembly  98  that functions as a shock absorber to reduce impact on the arm assembly  70  if a cow kicks any of the assembly components. 
     The arm assembly  70  is also connected to a downwardly extending arm support tube  100 . The arm support tube  100  fits in a telescoping relationship to the arm support bearing housing  102  which includes bearings (not illustrated) to permit the arm support tube  100  free vertical movement relative to the arm support bearing housing  102 . Further, the arm support bearing housing  102  can be used to adjust the limits of the vertical distance between the arm assembly  70  and the splash panel  22 . Preferably, the arm support tube  100  has a tapered top end to accommodate the sloping splash panel  22  (see FIG. 7 a ). 
     On top of the arm support tube  100  is connected the second clevis  60 . Also connected to the top of the arm support tube  100  is a second chain  106 . The second chain  106  extends upwardly through the splash panel  22 , over the top of a pulley  108 , and is connected to a counterweight  110 . The pulley  108  is mounted to the splash panel  22  using an appropriate pin, washer, and retaining ring assembly  112 . The second chain  106  is joined to the counterweight  110  using any suitable means such as a shackle and snap lock assembly  114 . The counterweight  110  is disposed for vertical movement inside a counterweight guide  116  which guides the counterweight  110  at about the same angle as the sloping splash panel  22 . 
     In operation, the detacher  20  moves from the fully extended position with the arm assembly  70  fully extended and the arm support tube  100  in its lower most or fully extended position, as illustrated in FIG. 2, to the retracted position, illustrated in FIG. 4, with the arm assembly  70  completely folded and the arm support tube  100  in its upper most position. Between these two positions, the arm assembly  70  moves horizontal and vertically simultaneously so that the resulting movement of the arm assembly  70  is in an arc. This arc-shaped movement is desirable to prevent the milking machine from dragging on a cow platform or hitting a curb along the edge of the cow platform as the milking machine is being detached. 
     FIGS. 5 b,    6   b  and  7   b  illustrate the relative motion of the first clevis  58  and the second clevis  60 , as described above. These figures also illustrate the sequence of movement by the first chain  64 , the first roller  66 , and the second roller  65 . As the first clevis  58  begins to rise so does the first roller  66 , but the second roller  65  remains at the same elevation, next to the bottom of the splash panel  22 . 
     As the first clevis  58  continues to rise along its acute angle the chain is drawn into the splash panel  22  because the rollers  65  and  66  are being spread apart. This continues until the first chain completely folds the arm assembly  70 . 
     To retract the detacher  20  from the fully extended position (FIG. 2 ), the pneumatic or electronic controls  36  activate the pneumatic\electronic controller  38  to exhaust air from the pneumatic cylinder  42  which in turn retracts the piston  44 . This action pulls upward on the first chain  64  which then begins folding the arm assembly  70 . As the piston  44  is retracted, the first clevis  58  begins rising as well, but because the first clevis  58  and the second clevis  60  are not in contact in the fully extended position, some distance must be traveled by the first clevis  58  before the two will engage. This is desirable so that the arm assembly  70  will begin folding before the arm assembly  70  and arm support tube  100  are raised up where they may strike the cow  16 . 
     As seen in FIG. 3, the first clevis  58  and the second clevis  60  are engaged and the arm assembly  70  has begun to fold. The first clevis  58  has lifted the second clevis  60  slightly, which in turn has pulled up the arm support tube  100  through a portion of the arm support bearing housing  102 . When the first clevis  58  and the second clevis  60  first engage their contact point is near the distal end of the respective clevises (FIG. 6 a ). As the first clevis  58  rises, it moves upward and to the left along an acute angle as illustrated in the sequence of FIGS. 5 a,    6   a,  and  7   a.  The arm support tube  100  does not move laterally within the splash panel  22 , rather the arm support tube  100  moves only in the vertical direction due to its positioning within the arm support bearing housing  102 . Therefore, it is necessary for the first clevis  58  and the second clevis  60  to slide relative to one another to accommodate the vertical and lateral movement of the first clevis. To achieve this goal, the first clevis  58  and the second clevis  60  are shaped as illustrated in the figures, although other shapes are possible as discussed above. 
     As also can be seen in FIG. 3, the counterweight  110  has moved downward within the counterweight guide  116 . The counterweight  110  aids the pneumatic cylinder  42  in lifting the weight of the arm support tube  100 , the arm assembly  70 , and the other components attached thereto. 
     Referring to FIG. 4, the detachers  20  has moved to the retracted position wherein the arm assembly  70  is completely folded and the arm support tube  100  has been moved to its upper most vertical position. It can be seen in FIG. 4, FIG. 7 a,  and FIG. 7 b  that the first clevis  58  and the second clevis  60  are not engaged. This is a result of the first chain  64  becoming fully tensioned prior to full cylinder retraction. The continued retract force of the cylinder  42  and piston  44  folds the arm assembly  70  in and vertically pulls up the arm support tube  100  against a stop in the arm support bearing housing  102 . 
     To reverse the process and extend and lower the detacher  20 , the pneumatic or electronic controls  36  activate the pneumatic\electronic controller  38  to lower the piston  44  which enables an operator to unfold the arm assembly  70  and pull down the arm support tube  100  to position the milking machine under the cow  16  and begin milking operations. The operator&#39;s pull causes the counterweight  110  and arm assembly  70  to move to the most desirable milking position as illustrated in FIG.  2 . 
     Additional details of the arm assembly  70  are depicted in FIGS. 8 through 10. As stated above, the arm assembly  70  includes three arm segments  74 ,  76 ,  78  that are joined together at hinges  80 . Each hinge  80  includes a cylinder  120  welded to the cylindrical rod  82  which is then joined to flanges  122  on an adjacent arm segment by a pin  124 . The pins  124  are joined to the cylinders using sets screws (not illustrated) and to the flanges  122  using appropriate retaining rings  126 . As stated above, the cylinders  120  and flanges  122  operates smoothly using appropriate bearings  127  and lubricant. As can be seen in FIG. 8, the pin  124  between arm segments  76  and  78  is extended with a lower cylindrical portion  128  to receive the hose hook  90 . 
     The chain bushings  88  in arm segments  76  and  78  are extended, as depicted in FIGS. 9 and 10 so that when the arm assembly  70  is completely folded the arm segments will be maintained in a spaced relationship to prevent pinch points from developing. In addition, a stop plate  130  is welded to the arm support plate  72  to maintain additional spacing and avoid pinch points. 
     Further, to avoid possible pinch points, the cylindrical rod  82 , as illustrated in FIG. 9, tends to force away anything that might otherwise be pinched at point  132 , for example. It can also be seen that rounding flanges  122  reduces the chance that anything can be pinched between adjacent arm segments. 
     Except where indicated above, the detacher components are desirably made of stainless-steel, plastic or other corrosion resistant material to withstand the conditions of a milking parlor. 
     The foregoing detailed description of drawings is provided for clearness of understanding only and no unnecessary limitations therefrom should be read into the following claims.