Abstract:
A retractable arm assembly for use in positioning a milker arm near the teats of a cow is disclosed. The retractable arm assembly allows a milker claw to be stored above a milking platform in a clean, safe position, and then automatically extended to the milking position and maintained in that position until the milker claw has been removed from the teats of the cow. The retractable arm assembly includes a movable milker arm having an interior chamber for receiving a chain to which the milker claw attaches. A lever arm connected to the milker arm faciliates movement of the milker arm in a downward and outward path around and behind the cow&#39;s rear leg. Both the chain and the milker arm can be selectively extended and retracted.

Description:
RELATED APPLICATIONS This application claims the benefit of priority to commonly-owned and copending U.S. Provisional Patent Application No. 60/811,179, which is incorporated herein by reference. 
    
    
     FIELD OF INVENTION  
       [0001]     The field of this invention is equipment for milking cows, and, more specifically, a retractable arm for use with automated milking equipment on a rotary platform. The retractable arm is stored inside an automation cabinet; it extends out of the cabinet to position the milker claw behind the cow for attachment by an operator.  
       BACKGROUND OF INVENTION  
       [0002]     Retractable arms have been used on rotary platforms for several years. Currently, DeLaval offers a folding, two-piece arm that moves in the horizontal plane, extending out from under the cabinet overhang to a position behind the cow. See generally U.S. Pat. Nos. 6,289,845, 6,752,101, and 6,843,203. A disadvantage of this arm is that it must be manually moved by the operator from the retracted/storage position to the milking position. Another disadvantage is that the arm tends to fold up and retract before the chain is retracted enough to pull the milker claw from the cow, which results in the chain dragging around the cow&#39;s leg.  
         [0003]     Westfalia-Surge has an arm that rotates from the milking position to a storage position, but this arm drops the milker claw below the milking platform. See U.S. Pat. Nos. 6,814,027 and 6,990,923. Applicant&#39;s invention allows the milker claw to be stored above the milking platform in a cleaner, safer position, while automatically extending the arm to the milking position and maintaining the arm in that position until the chain has been retracted sufficiently to remove the milker claw from the teats of the cow.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0004]     The invention has an arm assembly comprising a short pivotable upper arm that drives a longer lower milker cluster support or milker arm via a pivot point at the connection between the two pieces. The movement of the arm assembly is generally in a downward and outward direction from a milking cabinet in which it is housed. The movement of the milker arm is angled to improve the direction of movement of the lower milker arm toward the cow. The milker arm is also curved somewhat to allow it to stay behind the cow&#39;s rear leg. A chain is routed through a chamber in the lower milker arm. A distal end of the chain is attached to a milker claw that is attached to the cow&#39;s teats for milking.  
         [0005]     An air cylinder is attached to the upper arm to pivot it for retraction and extension. A second air cylinder retracts and extends the chain to the milker claw. When signaled by an input, the chain cylinder extends immediately, which extends the chain. After a short delay, the arm cylinder extends as well, thereby extending the arm and permitting attachment of the milker claw to the cow&#39;s teats.  
         [0006]     To retract the milker claw, the chain cylinder starts retracting the chain to draw the milker claw from under the cow to the end of the arm. After a slight delay to allow for that movement, the arm cylinder then retracts the arm into the cabinet, leaving the milker claw hanging in front of the cabinet beneath an overhang that shields it from access by both the exiting cow and the next cow entering the stall. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a front view of a retractable arm assembly of the invention with the arm retracted.  
         [0008]      FIG. 2  is a rear view of the retractable arm assembly with the arm retracted.  
         [0009]      FIG. 3  is a front view of the retractable arm assembly with the arm extended.  
         [0010]      FIG. 4  is a rear view of the retractable arm assembly with the arm extended.  
         [0011]      FIG. 5  is side view of a cabinet of the invention showing a cutaway of the retractable arm assembly with the arm retracted.  
         [0012]      FIG. 6  is side view of the cabinet showing a cutaway of the retractable arm assembly with the arm extended and further showing an extended chain with attachment for a milker claw.  
         [0013]      FIG. 7  is a diagram of an alternative embodiment of the air supply logic of the retractable arm assembly of the invention.  
         [0014]      FIG. 8  is a side view of the cabinet showing the retractable arm in the retracted position with the milker claw attached.  
         [0015]      FIG. 9  is a diagram of the air supply logic of the retractable arm assembly of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     As shown in  FIGS. 1 and 2 , a retractable arm assembly  1  comprises a short upper arm  6  that drives a longer lower milker arm  7  with a pivot point  18  at the connection between the upper lever arm  6  and a proximal end  21  of the lower arm  7 . As shown in  FIG. 2 , an arm air cylinder  2  operates the upper arm  6 . As shown in  FIG. 6 , a chain air cylinder  3  extends and retracts a chain  4 , a distal end of which is attached to a milker cluster or claw  5  (See  FIG. 8 ). As shown in  FIGS. 5 and 8 , each stall on a rotary milking platform assembly has a cabinet  70  that houses a milking control (not shown), as well as the retractable arm assembly  1 .  
         [0017]     As shown in  FIGS. 1, 4 , and  6 , the movement of the arm assembly  1  is in a plane that is angled from the vertical to improve the direction of movement of the lower arm  7  toward a cow. The lower milker arm  7  is slightly curved to allow it to stay behind the cow&#39;s rear leg during movement. The chain  4  is routed through the milker arm  7 , and attached to the milker claw  5 , as shown in  FIGS. 5 and 6 .  
         [0018]     As further shown in  FIG. 2 , the air cylinder  2  is mounted to a plate  9  at a pivot  10  and attached to the upper arm  6  with a rotating joint  11  at a bar  12 . (See also  FIG. 4 .) The bar  12  is attached to a gear  13  on a bearing block  14 , with a shaft  15  through the gear  13  and the bearing block  14 . As further shown in  FIGS. 2 and 4 , the gear  13  has teeth that mesh with teeth on a gear  16 , which is also mounted on the bearing block  14 . The gear  16  is on a shaft  17  that extends through the bearing block  14  and the mounting plate  9  and into the upper arm  6 . The gear ratio between gear  13  and gear  16  allows for the proper movement of the arm  6  when the rod  36  of cylinder  2  is extended or retracted by air pressure.  
         [0019]     The upper arm  6  could be made from structural tubing or simply from plates or bars that are connected to provide a strong member to drive the movement of the lower arm  7 . As shown in  FIG. 3 , the upper arm  6  has a bearing block  24  attached to the underside of the upper arm  6 . The bearing block  24  slides along plate  9 , thus, providing support with minimal friction.  
         [0020]     As also shown in  FIGS. 1 and 3 , the lower milker arm  7  is connected to the upper arm  6  with a pin  18  through a block  19  attached to the lower arm link  7   a . A wear bushing  22  is inserted into the upper proximal end  21  of the lower arm link  7   a  to guide the chain  4  into the upper end  21  of the lower arm  7 . See  FIG. 3 . In an alternative embodiment, a pulley (not shown) is attached to the block  19  to guide the chain  4  into the upper end  21  of the lower arm  7 .  
         [0021]     The lower arm  7  is made from a structural tube that will provide adequate strength and is hollow to allow passage of the chain  4  through it.  FIGS. 1-6  show a round lower arm tube  7 , but a square tube could also be used. As shown in  FIGS. 1-4 , at a lower distal end  23  of the lower arm  7  a wear bushing  24   a  is inserted that guides the chain  4  and provides a replaceable wear surface. The bushing  24   a  also directs the chain  4  at the appropriate angle toward the cow. The lower arm  7  moves through a plastic guide plate  25  that is attached to the plate  9  providing the entry/exit point for the lower arm  7  from the cabinet  70  and providing support with minimal friction to lower arm  7  throughout its movement.  
         [0022]     The air cylinder  3  ( FIG. 6 ) has a cylinder rod  40  that retracts and extends the chain  4  connected to the milker claw  5 . The cylinder  3  is mounted inside the cabinet  70  so the chain  4  is routed over pulleys  29  and  30  and into the upper end  21  of the lower arm  7 .  
         [0023]     An end  41  of the chain  4  is securely attached to a connector  41  a that is in slidable engagement with the cylinder rod  40 , as shown in  FIGS. 5 and 6 . The chain  4  extends through an opening in a housing of pulley  42 , up to and around a pulley  29   a , down around pulley  42 , back up over pulleys  29 ,  30 , and then down through lower arm  7 . Other suitable chain routings may be used in the event the stroke length of the cylinder rod  40  or the length of the cylinder  3  requires a different routing. Any routing and chain length that permits the chain  4  and milker claw  5  to reach under the cow for connection to the teats for milking will work satisfactorily.  
         [0024]     As shown in  FIGS. 1 and 2 , the pulleys  29  and  30  are mounted to a bracket  27  with a pivot pin  28 . The pivot pin  28  inserts into a pivot sleeve  31 , which is welded to a mounting bar  32 . The mounting bar  32  attaches to the cabinet  70  to provide support for the mounting plate  9 .  
         [0025]     As shown in  FIG. 7 , to attach the milker claw  5  to the teats of the cow, an operator presses a start button (not shown), thereby signaling an air valve  50  which supplies compressed air to the cylinders  2  and  3 . As shown in  FIGS. 6 and 7 , air is applied to the extend port  33  of the chain cylinder  3  so as to extend the chain  4 . After a brief delay, air is applied to the retract port  35  of the arm cylinder  2  thereby extending the upper arm  6 . (See  FIGS. 2 and 7 .) As the rod  40  of chain cylinder  3  extends, the weight of claw  5  pulls the chain  4  through lower arm  7 . At the same time, arm cylinder  2  is retracting due to air pressure being applied to the cylinder retract port  35 . As the cylinder rod  36  retracts into cylinder  2 , the bar  12  rotates the gear  13 , which in turn rotates the gear  16 . The gear  16  rotates the shaft  17 , which then moves the upper lever arm  6 . As upper arm  6  is moved downward it drives lower milker arm  7 , pivoting at the pin  18 , such that milker arm  7  moves on a path downward and outward to a position behind the rear leg of the cow, where the milker claw  5  may be attached to the cow&#39;s teats. Thus, the movement of the milker arm  7  describes a path around and behind the cow&#39;s rear leg to arrive at a position for optimal retraction of the milker claw  5  to the distal end of milker arm  7  in order to avoid contact of the chain  4  and the milker claw  5  with cow&#39;s rear leg. Moreover, the extension of the milker arm  7  may be delayed with regard to the extension of the chain  4  such that attachment of the milker claw  5  may begin prior to the arrival of the milker arm  7  at its extended position.  
         [0026]     To retract the milker claw  5 , the air valve  50  (see  FIG. 9 ) is signaled and air is applied to the retract port  37  of the chain cylinder  3  to retract the chain  4 , while air is exhausted from port  33 . At the same time, air is applied to the arm cylinder extend port  38 , delayed by a flow control, and retract port  35  is exhausted so the cylinder rod  36  of cylinder  2  moves the upper arm  6  to the retracted position. As the chain  4  is retracted into the cabinet  70 , it pulls the milker claw  5  from under the cow to the end bushing  24   a  of the lower milker arm  7 . As the milker claw  5  is pulled up against the end of the lower arm  7 , the delayed action of the arm cylinder  2  retracts the milker arm  7  on a path upward and inward into the cabinet  70 , leaving the milker claw  5  hanging in front of the cabinet  70  (see  FIG. 8 ) and above the milking platform, shielded from access by the cow when exiting a stall and also shielded from the next cow entering the stall. In this position the milker claw  5  is also in a position where it may be kept sanitary. After the chain cylinder  3  is air powered during retraction, a second air valve (not shown) may, if desired, be used to apply air to the extend port  38  of the arm cylinder  2 , after an adjustable delay. (See  FIG. 7 .)  
         [0000]     Retract Arm Air Logic:  
         [0027]     As shown in  FIG. 9 , the two cylinders  2  and  3  are controlled by a 4-way electric solenoid air valve  50  that is controlled by the stall milking controller (not shown). In the standby position, the lower arm  7  is retracted into the cabinet  70  and the milking claw  5  is hanging beneath the front of the cabinet  70 , as shown in  FIG. 8 . To attach the milker claw  5  to the cow, the operator presses the start button (not shown) on the cabinet  70 , which signals the milking controller to de-energize the solenoid of the air valve  50  and, thus, shifts the air supply from port  51  to port  52 . Compressed air is supplied to the extend port  33  of the cylinder  3  and simultaneously to the retract port  35   a  of the arm cylinder  2 . In an alternative embodiment shown in  FIG. 7 , the air supplied to cylinder  2  goes through a second 4-way electric solenoid air valve  53  which is in an open position when in the normal standby position.  
         [0028]     As compressed air enters the port  33 , a flow control valve  54  on the port  37  restricts the air flow out of the cylinder  3  to control the speed of the cylinder rod  40  as it extends. See  FIG. 9 . Simultaneously, as air enters the port  35   a  of the cylinder  2 , the flow control valve  38  on the port  38   a  restricts the air flow out of the cylinder  2  to control the speed of the cylinder rod  36  as it retracts.  
         [0029]     The arm assembly  1  is retracted when milk flow from the cow drops to a predetermined level as measured by a flow sensor or milk meter. The signal from the sensor or meter to the stall controller generates a signal from the controller to the valve  50 , energizing the solenoid and shifting the valve  50  so air is supplied to the port  51 . See  FIG. 9 . Air is released from the port  33  of the cylinder  3  as air enters the port  37 . Simultaneously, air is released from port  35   a  of cylinder  2 , so the cylinder  2  is no longer held in the retracted position. As the chain cylinder  3  retracts, it pulls the chain  4  into the end  23  of the arm  7  until the milker claw  5  is against the end bushing  24   a . Air is released from port  35   a , slowed by the flow control  35  of cylinder  2  as air enters port  38   a . The extension of rod  36  pulls the lower arm  7  (and thus the upper arm  6 ) into the cabinet  70 .  
         [0030]     When the milking session is ended, to facilitate cleaning the milking claw  5 , it is useful to release the chain  4  without extending the lower arm  7  from the cabinet  70 . In the alternative embodiment of  FIG. 7 , this may be accomplished by means of the second 4-way valve  53 . The valve  53  has a separate air supply and a separate power supply, and, in an alternative embodiment, is controlled by a switch on the cleaning unit door on the front of the cabinet  70 . When the cleaning unit door  70   m  is opened, a switch closes so as to allow power to the valve  53 , which then applies air to the port  55 , and, subsequently, to the port  38   a  of the cylinder  2 . The air so-supplied holds the cylinder  2  in the extended position, thereby keeping the upper arm  6  in the retracted position. In this mode, when the start button (or a specified cleaning mode button) is pressed, the valve  50  is de-energized, thereby applying air to the port  33  and extending the cylinder  3  to release the chain  4 , but the valve  53  prevents air from going to the port  35   a  of the cylinder  2  and extending the arm assembly  1 .  
         [0031]     When the cleaning process is completed, to prepare the system for milking, the chain  4  and the milker claw  5  are retracted by pressing a remove button. In an alternative embodiment, the cleaning unit door  70   m  is closed, thereby opening the switch and de-energizing the valve  53 . The air to the port  38   a  of the upper cylinder  2  is exhausted, and the arm assembly I is once again held in the retracted position by the arm cylinder  2 .  
         [0032]     For convenience, the milker claw  5  may be attached to the chain  4  by a spring hook  72 , as shown in  FIGS. 5, 6 , and  8 .  
         [0033]     Although the milker arm  7 , the chain  4 , and the lever arm  6  are described above as being moved, respectively, by the compressed air cylinder  3  and the rod assembly  40  and the air cylinder  2  and the rod assembly  36 , it is understood that the arm  7 , the chain  4  and the lever arm  6 , or any one or more of them could be moved by hydraulic cylinder and rod arrangements or electrical connections and components. It is also feasible to move the arm  7 , the chain  4 , and the lever arm  6 , or any of them, manually. Moreover, the lower arm  7  and the chain  4  could be moved manually toward the teats of the cow to be milked and locked in place for milking against the bias of springs; in this event the arm  7  and the chain  4 , when unlocked, would return to their storage positions due to the bias of the springs, with or without the use of the upper lever arm  6 . In addition, while the lever  6  and its linkages are described above as the actuators for moving the lower milker arm  7  and other components of the retractable arm assembly  1 , other types of actuators may be used. For example, a bell and crank actuator with appropriate linkages could be used in place of the upper lever arm. Pneumatic rotary actuators could also be used, as could actuators that comprise combinations of electrically operated or energized solenoids, pivots, and/or arms controlled by microprocessors or other types of control devices. Such actuators could be separately activated by a user or suitably programmed by the user or others to permit, as here, the retraction of the chain  4  before, after, or simultaneously with the movement of the milker arm  7  to its fully extended position or to its storage position, thus providing maximum flexibility, functionality, and efficiency in the use and operation of the milker arm  7  and the milker claw  5 . Such actuators could also be used, as above, to move the milker arm  7  around and behind the cow&#39;s rear leg to place it in the proper position for attaching or begin the attachment of the milker claw  5  while, at the same time keeping the chain  4  and milker arm  7  away from the cow and the milking platform.  
         [0034]     The changes described above, and others, may be made in the systems and methods described herein without departing from the scope hereof. It should thus be noted that the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall there between.