Abstract:
A teat cup assembly comprises an inflation having a plurality of radially-extending longitudinal ribs circumferentially spaced about the inflation and having a T-shaped cross-section. An outer shell for receiving the inflation comprises a plurality of longitudinally-extending slots having a T-shaped cross-section adapted for slidable communication with the ribs

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/320,035, filed Mar. 21, 2003, which is incorporated herein in its entirety. 

   FIELD OF THE INVENTION 
   This invention relates to teat cup assemblies for automatic milking machines. In one of its aspects, the invention relates to a teat cup assembly with a tubular inflation which is retained in a predetermined relationship to a teat cup outer shell during the operation of an automatic milking machine. 
   DESCRIPTION OF THE RELATED ART 
   Teat cup assemblies are used in automatic milking machines for milking cows and other animals. The teat is inserted into the teat cup assembly, which massages the teat to aid in extraction of milk therefrom and directs the extracted milk to a collection apparatus. U.S. Pat. No. 2,502,362 to Babson et al., issued Mar. 28, 1950, describes a teat cup assembly comprising a rigid tubular outer shell surrounding a flexible tubular inflation wherein the inflation and the interior surface of the shell have a triangular cross-section. U.S. Pat. No. 6,435,132 to Milbrath et al., issued Aug. 20, 2002, describes a similar teat cup assembly wherein the inflation has one or more longitudinal beads that appear to be tightly retained in mating channels in the shell. The inflations are slightly bowed between the longitudinal beads and require radial movement of the beads with respect to the channels during the inflation cycle in order to collapse inwardly. However, those inflations that are disclosed in the &#39;132 patent do not appear to be able to articulate in a radial direction, either outwardly or inwardly. This process will take an unacceptable amount of time and will also bring undue stress and fatigue on the wall of the rubber inflation. If the ribs are held tightly in the grooves as it appears from the drawings, then the walls of the inflation are unlikely to be able to collapse completely and touch during inflation cycle. If held at the grooves, the inner wall surfaces would have to stretch which would increase the response time and stress the inflation. On the other hand, if the ribs are not securely held by the grooves, the ribs might become dislodged from the grooves during the inflation cycles. Further, the tightness of the ribs in the grooves would make it difficult to feed the ribs along the grooves during assembly of the inflations in the shell. It would therefore appear that the teat cup assemblies illustrated in all Figures, except perhaps the single rib and groove combination of  FIG. 5 , would not be satisfactory in a typical milking machine. 
   SUMMARY OF THE INVENTION 
   According to the invention, a teat cup assembly has a shell and a flexible inflation mounted therein wherein the shell has a plurality of interior longitudinal channels, each with at least one retaining flange that defines an edge of a slot in the channel that faces the interior of the shell, and the inflation has an external rib in each of the channels and that is retained for radial articulation within the channels during inflation and deflation of the inflation. The interior longitudinal channels and the external ribs are shaped to provide radial articulation of the external ribs during inflation and deflation of the inflations. 
   In one embodiment, the external ribs of the inflation have a neck that is received in the slot of the shell channel and at least one laterally extending flange that seats radially outwardly of the shell retaining flange. Preferably the ribs extend longitudinally within the channel. Further, the ribs can be generally complementary in shape to the longitudinal channels while still providing for radial articulation of the ribs within the channels. 
   In a preferred embodiment of the invention, each of the channels is T-shaped in cross-section. Further, the longitudinal ribs are also preferably T-shaped. The T-shaped ribs preferably fit loosely within the T-shaped channels for radial articulation of the T-shaped ribs with respect to the T-shaped channels during an inflation and deflation cycle. 
   The invention also contemplates that the interior longitudinal channels and the ribs can take various forms so long as the ribs are retained within the channels during inflation and deflation of the inflation and so long as the ribs can articulate within the interior longitudinal channels during the inflation and deflation cycle. Thus, the interior longitudinal channels and the ribs can be L-shaped in longitudinal cross section so that there is only one retaining flange of the channel and only one laterally extending flange on the rib. 
   In a preferred embodiment of the invention, there are three interior T-shaped longitudinal channels although the invention contemplates  2 ,  4  or more interior T-shaped longitudinal channels. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a longitudinal sectional view of a teat cup assembly comprising a shell and an inflation according to the invention. 
       FIG. 2  is a sectional view of the teat cup assembly of  FIG. 1  taken along line  2 — 2  thereof showing the inflation in an uncollapsed state. 
       FIG. 3  is a sectional view of the shell shown in  FIGS. 1 and 2 . 
       FIG. 4  is a sectional view of the inflation shown in  FIGS. 1 and 2 . 
       FIG. 5  is a sectional view similar to  FIG. 2  of a teat cup assembly showing the inflation in a collapsed state. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings, a teat cup assembly  40  comprises an outer shell  42  and an inflation  54 . The outer shell  42  is a hollow, elongated body comprising an annular wall  44  having a curved inner surface  46  to define a bore  45 . Extending radially from the surface  46  into the annular wall  44  is a plurality of longitudinal channels  48  in a preferred embodiment of three channels  48  spaced at 120° apart. Each channel  48  comprises a radial slot  50  opening into an arcuate chamber  52  to form a generally T-shaped channel. 
   The inflation  54  is a tubular member formed from a flexible elastomeric material such as natural or synthetic rubber. The inflation comprises an annular wall  56  having a curved outer surface  58  and a curved inner surface  60 . The inner surface  60  defines a duct  62  for receiving a cow&#39;s teat  20  in a generally conventional manner. Extending radially outwardly from the outer surface  58  is a plurality of longitudinal ribs  64 . In the preferred embodiment illustrated in the drawings, there are three ribs spaced at 120° apart. The ribs  64  comprise a neck  66  extending radially outwardly from the outer surface  58  and terminating generally orthogonally in an arcuate flange  68  for slidable communication with the channels  48 . The ribs  64  are retained within the channels  48  by slidably inserting the flanges  68  into the arcuate chambers  52  with the necks  66  extending through the slots  50  to define three defined but communicable pressure chambers  70 . As illustrated in the drawings, the ribs  64  fit loosely within the channels  48  so that they can articulate radially during the inflation and deflation cycle. 
   The operation of the teat cup assembly  40  is as follows. A vacuum is applied to the duct  60  while the pressure chambers  70  are alternately evacuated by connection to a vacuum source and connected to atmosphere air in order to impart a massaging motion to the inflation  54  and the teat  20 . When the pressure chambers  70  are connected to atmospheric pressure, the annular wall  56  collapses radially inwardly, as shown in  FIG. 5 , thereby pulling the ribs in a radial direction. Because of the loose tolerances of the ribs  64  in the channels  48 , the ribs  64  freely articulate in a radial direction. The flange  68  on the ribs  64  retains the ribs within the channels  48 . 
   The configuration of the ribs  64  and the channels  48  facilitates the installation of the inflation  54  in the outer shell  42  since the flanges  68  can be slidably inserted into the chambers  52  as the inflation  54  is inserted into the bore  45 . The chambers  52  are somewhat larger than the flanges  68 , facilitating insertion of the flanges  68 . During the collapse of the inflation  54  with atmospheric pressure in the pressure chambers  70 , as shown in  FIG. 5 , the necks  66  can stretch if necessary to accommodate the inward radial displacement of the inflation  54 . Because the flanges  68  are securely retained in the chambers  52 , the inflation  54  remains fully supported in the outer shell  42 . 
   While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. For example, the teat assembly can have fewer or more than three ribs and channels. The invention is equally applicable to teat cups having two or four rib and channel sets. Reasonable variation and modification are possible within the scope of the forgoing description and drawings without departing from the spirit of the invention, which is described in the appended claims.