Abstract:
An apparatus for installing and removing a teat cup liner (or “inflation”) from a shell has a fixture which holds and retains the shell in position. A pair of shoes is capable of moving to engage a portion of the liner projecting from the shell to pull the liner downwardly. In an installation mode, the liner is pulled so that a sealing ring on the liner moves through a restricted opening into a sealing relationship with the shell at one end. The resiliency of the liner also causes a seal to be formed at the other end of the shell. In a removal mode, the liner is stretched by movement of the shoes in the same way as installation. A cutter of the apparatus is then activated to sever an end portion of the liner, including the sealing ring from the remainder of the liner, releasing the liner from the shell.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to teat cup assemblies for vacuum-operated milking machines including a rigid shell and a flexible liner, and in particular to an apparatus for installing and/or removing the flexible liner from the shell. 
     Automatic milking machines employ teat cup assemblies having a hollow, rigid outer shell and a resilient liner (also called an “inflation”) including a tubular body installed within the shell in a manner to form a seal at both ends of the shell. The terms “inflation” and “liner” are used interchangeably in the trade. The shell and liner define an annular chamber there between to which a pulsating vacuum can be applied. The cow&#39;s teat is inserted into the upper end of the liner and a milking tube portion on the lower end is connected to a manifold (called a “claw”) of the milking machine. During the milking operation, a pulsator switches on and off to apply a vacuum to the chamber in the teat shell  12  that causes the liner  14  to expand, increasing its internal diameter and relieving pressure on the teat. The pulsator can then vent the chamber to atmosphere and the liner  14  contracts, squeezing the teat to express milk therefrom into the liner. 
     One type of conventional teat cup assembly  10  is shown in  FIGS. 1 and 2  and has a generally cylindrical shell  12  and removable liner  14  (the reference numbers indicating their subjects generally). The shell  12  has a tubular body  15 , a lower end  16  including an opening  17  of reduced diameter and an upper end terminating in a rim  18 . Located in the side of the shell  12  is an air tube  19  connected via suitable tubing (not shown) in communication with the pulsator which alternately vents to atmosphere and applies a vacuum to an annular chamber between the interior wall of the shell  12  and a portion of the liner  14  inside the shell to alternately squeeze and release the teat to express milk. The shell  12  can be made from a metal, such as stainless steel, or a synthetic thermoplastic or thermosetting material, including transparent or translucent materials so that the milking operation of the liner  14  can be observed. 
     The liner  14  has an elongated, generally cylindrical suction sleeve or barrel section  20  which fits inside the shell  12  and a head section  22  which has a circular opening  24  for receiving a cow&#39;s teat. The head section  22  has a peripheral downwardly extending skirt or cuff  26  which surrounds the rim  18  of the upper end portion of the shell  12 . The cuff  26  is spaced radially outwardly from the outer wall of the liner  14  to define an annular recess which receives and sealingly engages the rim  18  of the shell  12 . The liner  14  also has a lower section  30  which fits through the opening  17  in the lower end  16  of the shell  12 . A sealing ring  28  on the liner  14  is sized to be pulled through the opening  17  and sealingly engage the shell  12  so that the liner is elongated and under tension when assembled within the shell. In this way, the liner  14  seals with the shell  12  at the cuff  26  and the sealing ring  28  and makes the annular chamber airtight. The liner  14  may be a one-piece unit or a multiple-piece unit. The liner  14  can be made from any of a variety of conventional elastomeric materials such as synthetic or natural rubber. The cuff  26  has an upper alignment mark  27  that corresponds to another lower alignment mark  29  directly under the sealing ring  28  on the lower section  30 . When installed correctly, mark  27  on the cuff  26  and mark  29  on the lower section  30  must be aligned with each other to avoid twisting. The construction of the teat cup assembly is conventional and may be varied without affecting the scope of the present invention. 
     During milking operation, the barrel section  20  of the liner  14  is subjected to repeated alternating stretching and releasing by the vacuum system, which eventually breaks down the barrel section  20  and results in an inefficient or incomplete expression of milk. Additionally, the liner  14  is vulnerable to deterioration caused by scalding water, teat treatment preparations, cleaning chemicals, and an accumulation of butterfat. Also the head section  22  and lower section  30  can be subjected to a number of potentially damaging conditions such as flexing when not in use or impacts, e.g., dropping on a concrete floor or drain grating of a milking stall, banging into a milking stall wall, another teat cup assembly  10  or other equipment, or being stepped on by a cow. Any or all of these conditions could result in the downgrading or rejection of the bulk milk due to contamination, as well as unsafe for the health of the cow. Accordingly, it is recommended by all manufacturers of the liner  14  that replacement be routinely scheduled in order to maintain a uniform and efficient operation, maximize milk yield, and provide gentle, fast, and safe milking to preserve udder health. 
     SUMMARY OF THE INVENTION 
     An apparatus of the present invention is for manipulating a teat cup assembly used for milking a domestic animal. The teat cup assembly includes a shell and a resilient liner adapted to receive the animal&#39;s teat. The liner is capable of extending through the shell while being retained by the shell. Generally, the apparatus comprises a fixture sized and shaped for receiving and holding the shell having the liner retained therein, and a puller disposed relative to the fixture to grip and pull the liner relative to the fixture. 
     In another aspect of the present invention, the apparatus as set forth above, further including a frame mounting the fixture and puller. 
     Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevation of a prior art teat cup assembly; 
         FIG. 2  is the elevation of  FIG. 1  with a liner exploded from the shell; 
         FIG. 3  is a perspective of an apparatus for assembling and disassembling teat cup assemblies; 
         FIG. 4  is the perspective of  FIG. 3  with a housing of the apparatus and teat cup assembly removed; 
         FIGS. 5 and 5A  are front elevations of the apparatus of  FIG. 4 ; 
         FIG. 6  is the perspective of  FIG. 4  with a cutter and a left cover plate removed; 
         FIG. 7  is a left side elevation of the apparatus of  FIG. 3  with the pulling mechanism in an initial orientation; 
         FIG. 8  is a left side elevation of  FIG. 6  with the pulling mechanism in an intermediate orientation pulling a liner; 
         FIG. 9  is a left elevation of  FIG. 6  with the pulling mechanism in a final orientation stretching the liner below the shell; and 
         FIG. 10  is a schematic fluid circuit of the apparatus. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 3 and 4 , an apparatus indicated generally at  40 , used for assembling and disassembling shell  12  and liner  14  of teat cup assembly  10  according to one embodiment of the invention is shown. The apparatus  40  includes a left cover plate  44 , a right cover plate  45 , front spacer panel  46 A, top spacer panel  46 B, back spacer panel  46 C, and bottom spacer panel  46 D (see,  FIG. 6 ) located between, and spacing apart, the left cover plate  44 , the right cover plate  45 , and feet  47  supporting the center frame in an upright position. The center frame  42  encloses part of a mechanism (to be described hereinafter) that drives operation of the apparatus (see  FIG. 6 ). A housing, generally indicated at  48 , encloses other operating components of the apparatus including a pulling mechanism, indicated generally at  50 , and a cutter mechanism, indicated generally at  52  (shown in  FIG. 4  with the housing  48  removed), both of which will be more fully described below. Those of ordinary skill in the art will readily appreciate the construction and operation of teat cup assemblies  10 , previously described herein. Accordingly, additional details of construction and operation of the teat cup assembly  10  will not be described herein. 
     A teat cup assembly receiving fixture, generally indicated at  54 , projects upward through the top surface of the housing  48 . The teat cup assembly receiving fixture  54  is mounted on a platform  56  cantilevered from the left cover plate  44  and comprises a generally cylindrical receiving tube  58  open at an upper end  60  and having an internal rim  62  ( FIG. 4 ) forming a small opening  64  at the lower end thereof. The small opening  64  extends through the platform  56 . The receiving fixture  54  is configured to receive and hold the shell  12  of the teat cup assembly  10 , with or without the liner  14 . The receiving tube  58  has a diameter slightly larger than the diameter of the shell  12  so that the shell  12  can be received into the tube  58  through the upper end  60  and rest on the internal rim  62  to hold the shell within the receiving fixture  54 . A fixture slot  65  in the receiving tube  58  is configured to accommodate the air tube  19  when the teat cup assembly  10  is inserted into the receiving fixture  54 . The platform  56  of the teat cup assembly receiving fixture  54  is fixed to the left cover plate  44  using suitable brackets and fasteners (not shown), although other means of fixing the platform  56  may be used without departing from the scope of the invention. The apparatus  40  has the described teat cup receiving fixture  54  and associated pulling mechanism  50  and cutter mechanism  52  on the left side of the center frame  42 , and a substantially identical second teat cup receiving fixture  54 ′ and associated pulling mechanism  50 ′ and cutter mechanism  52 ′ on the right side of the center frame  42  such that the apparatus can assemble or disassemble shells  12  and liners  14  of two teat cup assemblies  10  simultaneously (see  FIG. 5 ). Corresponding parts on the right side of the apparatus  40  (as seen in  FIG. 5  and  FIG. 5A ) are designated by the same reference numeral with the addition of a prime. Any apparatus capable of assembling and/or disassembling one or more shells  12  and liners  14  does not depart from the scope of this invention by reason of the number of shells and liners handled at the same time. 
     The cutter mechanism  52  (shown on the left side of  FIG. 5A ) comprises a cutter cylinder  66  having a rod  66 A (broadly, “a blade driving device”) and a blade  67  mounted on the free end of the rod  66 A. The cutter cylinder  66  pushes the blade  67  toward the left cover plate  44  to cut the barrel section  20  of the liner  14  (as shown in phantom in  FIG. 5A ) when disassembling the teat cup assemblies  10 . On the left side of  FIG. 5A , the liner  14  (in phantom) is shown with the pulling mechanism  50  fully rotated, the cutter rod  66 A of the cutter mechanism  52  fully extended, and the barrel section  20  severed. In the illustrated embodiment, the cutter cylinder  66  is a modified Model NR091.5DXP manufactured by Bimba available from John Henry Foster Company of St. Louis, Mo. Naturally, air cylinders are not the only type of driving device coming within the scope of the invention. Driving devices could include any actuator which may apply adequate force to move the blade  67  toward the left cover plate  44  to cleave the liner  14 . The cutter cylinder  66  is mounted on a plate  66 B attached to and depending from a free end of the platform  56 . 
     A catcher  68  is pivotally mounted on the left cover plate  44  and extends through the housing  48  via catcher slot  69  ( FIG. 3 ). A finger  68 A projects laterally outwardly from the catcher  68  and can be positioned generally above the teat cup assembly receiving fixture  54 . The catcher  68  is configured to pivot between a first position (shown in  FIG. 7 ) wherein the finger  68 A is positioned away from the open end of the receiving fixture  54  so that the teat cup assembly  10  may be freely inserted or removed from the receiving fixture  54  and a second position ( FIGS. 8 and 9 ) wherein the finger  68 A is adjacent to the top of the teat cup assembly  10  in the receiving fixture  54  during either the assembly or disassembly cycle. The catcher  68  is positioned above the teat cup assembly  10  so that when the liner  14  is cut in two, the upper barrel section  20  of the liner  14  is retained within the receiving fixture  54 . One skilled in the art will appreciate that other methods of preventing the liner  14  from springing from the receiving fixture  54  when cut can be used without departing from the scope of the invention. Moreover, the catcher  68  could be eliminated in another embodiment of the invention (not shown). 
       FIG. 6  illustrates the apparatus  40  with the housing  48  and the left cover plate  44  removed for clarity. The pulling mechanism  50  comprises a rack  70  positioned within the center frame  42 . In the illustrated embodiment, the rack  70  is a Model #14½° PA 00540G 88165 24″ RA 16×2 rack available from Motion Industries of Quincy, Ill. Opposite sides  71 ,  72  of the rack  70  have teeth  74  along the length of the rack  70 . An air cylinder  76  (broadly, a “rack driving device”) is connected to the rack  70  by a rod  78  having a Magnaloy alignment coupler  77  and provides the driving force to move the rack  70  upward and downward. A guide block  75  receives and guides the rack  70  in its vertical movements. In the illustrated embodiment, the air cylinder  76  is a modified Model 505DXP air cylinder manufactured by Bimba available from John Henry Foster Company of St. Louis, Mo. It will be appreciated that other actuators may be used without departing from the scope of the present invention. 
     The pulling mechanism  50  further includes a pair of pinion gears  80  rotatably mounted on the left and right cover plates  44 ,  45 . As shown, the pinion gears are each a Model #14½° PA 00540G 91118 51684, available from Motion Industries of Quincy, Ill. Each pinion gear  80  has teeth  82  around the outer circumferential surface thereof for engaging the teeth  74  of the rack  70 . Movement of the rack  70  in either direction causes the pinion gears  80  to counterrotate. A shaft  84  extends from the rotational center of each of the pinion gears  80 . Each shaft  84  is fixed for conjoint rotation with its respective pinion gear  80 , and is supported by a pillow block  85 . An arm  86  projects radially from an outward end of the shaft  84  and is attached to the shaft with a pin. Other structures for connecting the arm  86  to the shaft  84  may be used without departing from the scope of the invention. As will be explained more fully below, rotation of each pinion gear  80  causes the arm  86  to pivot about an axis of rotation A of the gear  80 . The pulling mechanism  50 ′ on the right side of the center frame  42  has the same components as described for the pulling mechanism  50 . Arms  86 ′ and arcuate shoes  92 ′ are mounted for conjoint rotation with respective ones of the same pinion gears  80  which mount the shafts  84 . Thus, the air cylinder  76  simultaneously operates pulling mechanisms  50  and  50 ′. 
     A shoe  92 , (broadly, “a gripping device”) is fixed to a distal end of each of the arms  86 . The shoe  92  is configured to engage the lower section  30  of the liner  14  that extends below the opening  17  at the lower end  16  of the shell  12 . In one embodiment, the shoe  92  has a generally arcuate shape. The curve of the arc extends in a direction around the axis A. Thus, when the shoes  92  are in opposed relation, the space between remains substantially constant. Other shapes for a shoe (not shown), such as a series of straight segments forming a generally curved section and the like are contemplated. Additionally, a shoe can be bulb-shaped or other suitable shape for engaging the liner  14 . The arcuate shoe  92  suitably has a length between about 2 and about 6 inches, and more suitably has a length between about 3 and about 5 inches. The shoe  92  desirably has an engagement surface  94  for contacting the liner  14  and is made of a suitable high friction material, such as fiber-cork pads available from McMaster-Carr Supply Company of Chicago, Ill. The engagement surface  94  is also resiliently deformable, providing cushioning to prevent damage to the liner  14 . 
     Operation of the apparatus  40  is controlled using a fluid circuit illustrated schematically in  FIG. 10 . The circuit includes an activating switch  100  capable of being connected to a supply of compressed air through line  102 . In the default position of the activating switch  100 , the pressurized air is directed to the air cylinder  76  and cutter cylinders  66 ,  66 ′ via line  103  so that all cylinders are retracted. By depressing and holding down knob  100 A, air is redirected through line  104  to the air cylinder  76  to cause the main rod  78  to extend. Air cylinder  76  has flow controls  106  associated with it that are selected to cause the rod  78  to extend (and retract) at a predetermined rate. At the same time, air is also directed to a cutter selector switch  108 , which as shown in  FIG. 10  is open so that air cannot pass toward the cutter cylinders  66 ,  66 ′. The cutter selector switch  108  is set this way for installation of the liner  14  into the shell  12 . 
     Turning the cutter selector switch  108  to the closed position to activate the cutter mechanisms  52 ,  52 ′ allows air from the activating switch  100  to pass through the cutter selector switch  108  through line  110  to delay switch  112 . Air cannot pass through the delay switch  112  until it is tripped when the rod  78  of the air cylinder  76  reaches its full extension. In one embodiment, a trip control  112 A of the delay switch  112  is positioned so that one of the arms  86  engages the trip control  112 A at the bottom end of its motion (i.e., in the position shown in  FIG. 9 ). When the delay switch  112  is tripped, air is allowed to pass to the cutter cylinders  66 ,  66 ′ through lines  114  and  116  for cutting the liner  14  to disassemble it from the shell  12 . After the knob  100 A is released, the fluid circuit returns to its start position with the rods  66 A,  66 A′ and  78  of the air cylinders  66 ,  66 ′, and  76  in a retracted position. Other control arrangements, including those employing electronic controls may be used without departing from the scope of the present invention. 
     Referring now to  FIGS. 7–9 , upward and downward movement of the rod  78  of the air cylinder  76  causes corresponding upward and downward movement of the rack  70 . The linear movement of the rack  70  is translated into rotational movement of the pinion gears  80  through engagement of the teeth  74  of the rack with the teeth  82  of the pinion gears. For example, as the rack  70  is moved downward, one pinion gear  80  (i.e., the left gear in  FIG. 7 ) rotates in a clockwise direction and the other pinion gear  80  (i.e., the right gear in  FIG. 7 ) rotates in a counterclockwise direction causing the shoes  92  to move toward each other and down. When the rack  70  is moved in the upward direction, the one pinion gear  80  rotates in the counterclockwise direction and the other pinion gear  80  rotates in the clockwise direction causing the shoes  92  to move upward and then away from each other. 
     As seen in  FIG. 7 , the arcuate shoes  92  begin in an upward orientation such that a gap between the arcuate shoes  92  is wider than the lower section  30  of the liner  14 . The engagement gripping surfaces  94  of the shoes  92  are not opposed to each other. In this start position, the air cylinder  76  has fully retracted the rod  78  and raised the rack  70  to its upwardmost position. The catcher  68  is pivoted back so that the finger  68 A is not above the teat cup receiving fixture  54 . The teat cup assembly  10  is placed in the receiving fixture  54 . The lower section  30  of the liner  14  extends downward and is free to pass through the platform  56  and between the arcuate shoes  92 . Downward movement of the rack  70  causes the pinion gears  80  to rotate about their axes of rotation. The shoes  92  move toward each other and the engagement gripping surfaces  94  engage the lower section  30  of the liner  14  and pinch the liner  14  there between as shown in  FIG. 8 . Further downward movement of the rack  70  causes the shoes  92  to pivot to a generally downward orientation as shown in  FIG. 9 . The engagement gripping surfaces  94  of the shoes  92  frictionally engage the liner  14  and pull the liner  14  in a downward direction. The elastomeric nature of the liner material allows the liner  14  to stretch and elongate without breaking. 
     To assemble a liner  14  with a shell  12 , rim  18  of the shell  12  is inserted into cuff  26  of the liner  14 . The shell  12  is then placed into the receiving fixture  54  so that the lower section  30  projects below the opening  17  in the bottom of the shell  12 , but the sealing ring  28  is located within the shell  12  above the opening  17 . This description will focus on the assembly of one liner  14  with one shell  12  by pulling mechanism  50  on one side of the apparatus  40 , it being understood that a second liner and shell (not shown) could be simultaneously assembled by the apparatus  40  by the pulling mechanism  50 ′ on the opposite side. Thus, the shell  12  and liner  14  are unassembled and there is no sealed chamber within the shell  12  for the application of a pulsating vacuum needed to milk a cow. The cutter selector switch  108  is turned to the open position so that the cutter mechanisms  52 ,  52 ′ are inactive. The knob  100 A of the activating switch  100  is depressed and held down to initiate extension of the rod  78  from the air cylinder  76 . The shoes  92  engage the liner  14  and pull it in a downward direction until the sealing ring  28  on the liner  14  snaps through the opening  17  in the lower end  16  of the shell  12 . The sealing ring  28  of the lower section  30  of the liner  14  bears around the opening  17  and seals the liner  14  with the shell  12 . The cuff  26  of the head section  22  of the liner  14  bears around the rim  18  and seals the liner  14  with the shell  12 . In this way, the sealed chamber between the shell  12  and liner  14  is formed. The knob  100 A is released, causing the air cylinder  76  to retract the rod  78  and return the shoes  92  to the start position releasing the liner  14 . The upper mark  27  on the head section  22  of the liner  14  is now aligned with the lower mark  29  on the lower section  30  of the liner  14 . The assembled teat cup assembly  10  can be removed from the receiving fixture  54  and used for milking. 
     The apparatus  40  can also disassemble the shell  12  and liner  14 . When disassembling the teat cup assemblies  10 , the cutter selector switch  108  is turned to the closed position so that the cutter mechanism  52  will be active. The teat cup assembly  10 , with the liner  14  sealingly attached to the shell  12 , is dropped into the receiving fixture  54 . The lower section  30  of the liner  14  extends through and below the platform  56 . The knob  100 A of the activating switch  100  is pushed down and held, causing the shoes  92  to move from the raised position in  FIG. 7  together and downward. The shoes  92  engage the liner  14  as they move downward, and are shown in  FIG. 8  at a mid-stroke position somewhat after the initial engagement with the liner. The shoes  92  continue downward, pulling liner  14  in a downward direction to the position shown in  FIG. 9 . The downward pull continues until the sealing ring  28  is below the blade  67  of the cutter mechanism  52  ( FIG. 9 ). One of the shoes  92  presses the trip control  112 A of the delay switch  112 , causing the cutter mechanism  52  to rapidly extend to cut the liner  14  (see  FIG. 5A ). After releasing the knob  100 A, the shoes  92  move to the upward position. The lower section  30  and part of the barrel section  20  of the liner  14  including the sealing ring  28  fall down permitting the remainder of the barrel section  20  and head section  22  of the liner  14  to be easily removed from the shell  12 . The finger  68 A catches the head section  22  and prevents the barrel section  20  and head section  22  of the liner  14  from flying from the shell  12  and receiving fixture  54  when the elastic tension is released upon cutting the liner  14 . The shell  12  can then be reassembled with a new liner  14  as described previously.  FIG. 7  shows the delay switch  112  not engaged, the shoes  92  retracted, the rack  70  in the up position, and the arm  86  positioned away from the receiving fixture  54 .  FIG. 9  shows the delay switch  112  engaged, the shoes  92  in the fully rotated position, the rack  70  in the down position, and the catcher  68  extended over the receiving fixture  54 . 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     As various changes could be made in the above without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.