A TEAT CUP ASSEMBLY FOR USE IN AN AUTOMATIC MILKING SYSTEM

Abstract: A teat cup assembly for use with a silicon liner includes a one piece shell (12) with an integral peripheral protecting wall (46) which projects beyond the end of the cylindrical shell wall (14) and forms a recess (44) for receiving a cuff (35) of the liner. The wall (46) protects the end of the inflation from damage caused by impact with the floor or other articles in the milking parlour. No other mechanical parts are required to maintain the liner and assembly in the shell.

Description: This invention relates to a teat cup assembly for use in an automatic milking system. Use of silicon inflations or liners rather than natural or synthetic rubber in teat cup assemblies is known to be desirable. An article in New Zealand Journal of Dairy Science and Technology, 12.238-241, 1977, discusses the advantages of use of silicone as compared to teat cup liners made from synthetic or natural rubber. Basically the silicone inflations or liners do not absorb butter fat and oils or moisture as do the rubber liners. Additionally, silicone has resistance to extremes of temperature, ability to retain its flexibility even at low temperatures and good resistance to sunlight, oils, solvents and other chemicals. However, the silicone does have certain disadvantages and the commercial silicone teat cup liners suffer from these disadvantages. Silicone has a low tear resistance and is easily punctured. This problem is noted as the primary disadvantage of silicone liners in the above-cited New Zealand article. In the art silicone inflations have been developed to fit existing shells designed for rubber inflations and very little attention has been devoted to developing a shell adapted to protect the silicone inflation. In one prior art device made by BouMatic the distal end of the liner is exposed to impact and can be damaged by a variety of impacts for example, hitting a concrete floor, or the grates in the milking parlour, hitting other cups or equipment and even being stepped on by the cow. An impact on the distal end can cause a shearing action of the cap and shell to cause damage. Accordingly, the useful life afforded by the use of silicone which is normally significantly higher than that for a rubber inflation can be shortened considerably by an impact of this character which can split, tear or cause puncturing of the silicone inflation. US-PS 4,459,938 discloses a teat cup assembly employing a two-piece silicone rubber inflation with an entrance member and inflation. The assembly comprises a rigid, tubular shell and an elongate, tubular, inflation member received longitudinally within the shell. A sheet of metal is wrapped around the shell and an elongate sleeve member is adapted to fit telescopically over the sheet of metal which is wrapped about the shell. Teat entrance means are provided at one end of the inflation for receiving a teat of an animal to be milked and means are provided adjacent to the other end of the inflation to connect the assembly with a source of vacuum. This patent specification shows a structure which is difficult to assemble and disassemble and results in hard to clean pockets which can collect dirt. Other types of shell constructions such as those illustrated in U.S. Patent Specification Nos. 4,332,215; 4,116,165 and 3,659,557 show shells which afford some protection for the distal end of the liner but require a ring to expand the liner to secure the liner in place in the shell and to provide a seal. The machine installation process to install the ring can tear the liner if a silicone liner is employed. According to one aspect of the present invention, there is provided a teat cup assembly for use in an automatic milking system which includes a source of constant vacuum and a source of pulsating vacuum, said teat cup assembly including a teat cup shell with means on the shell for connection to the sources of the vacuum and a teat cup inflation having a distal end and proximal end and an inturned flange spaced from the distal end and formed of silicone rubber, the inflation further including a longitudinal teat receiving chamber and a cuff, which includes the flange and a spaced wall portion, and said shell has a generally cylindrical wall portion with a distal end and proximal end and a peripheral protective wall portion joined with said shell on the outside thereof adjacent the distal end, characterised in that said wall portion is spaced from and projects axially beyond said distal end of said inflation and its flange, and forms an annular recess which receives the wall portion of the cuff, thereby to protect the cuff from damage. There is accordingly provided an easy-to-clean, inexpensive one piece teat cup assembly with integral liner and shell. The protective flange on the shell can extend and diverge or taper outwardly from the cylindrical body to afford a wedging fit of the liner to provide effective sealing of the liner cuff to the shell at the inlet end. The protective flange will also prevent water from collecting between the shell and inflation in the vacuum chamber. This engagement also prevents the inflations from twisting, or liner becoming out of alignment, during normal machine use. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which the single Figure is a sectional view of a teat cup assembly. The drawing shows a teat cup assembly 10 which includes a teat cup shell 12 which has a cylindrical wall portion 14 having a distal end 16 and a proximal end 18 which is adapted to be connected to a connector 20 with a nipple 21 which is connectable to a source of constant vacuum. The shell 12 also includes an integrally formed small diameter pipe 22 which is connectable to a source of pulsating vacuum as is conventional in teat cup assemblies. A flexible inflation 30 is formed of silicone rubber and includes a generally cylindrical wall portion which forms a longitudinal teat receiving chamber 32 with a distal end 34 and cuff 35 including a spaced annular peripheral wall 36 joined to the cylindrical wall 32 by a connecting web portion 38. The annular wall 36 has an inwardly extending or inturned flange or lip 40. The cuff 35 includes an extension 42 on the wall 36 which is a continuation of the wall 36 and extends downwardly from the web portion 38 as viewed in the Figure. The overall outline of the cuff is similar to that shown in US-PS 4,372,250 for a rubber inflation except the cuff 35 can be wedge-shaped. The end extension 42 wedges within the recess 44 formed by the shell protecting wall portion or flange 46 which is connected to the shell by a juncture portion 48. The flange 46 is flared outwardly and projects beyond the distal portion 16 of the shell in an axial direction. The cylindrical wall portion 14 and wall portion 46 define the recess 44 which is ring-shaped and frusto-conical in section. The wedging fit of the cuff 35 in the recess 44 prevents twisting of the liner distal end in the shell. Adhesive can be applied at 47 to secure the inflation in the shell. Use of the integral flange 46 prevents entry of water into the shell during washing which can occur with cap type assemblies. The protective wall portion 46 provides lateral protection to the cuff 35 of the silicone liner to prevent direct mechanical contact and impact on the silicone liner. This greatly enhances the life of the silicone liner.

Claims: A teat cup assembly for use in an automatic milking system which includes a source of constant vacuum and a source of pulsating vacuum, said teat cup assembly including a teat cup shell (12) with means (21,22) on the shell for connection to the sources of the vacuum and a teat cup inflation (30) having a distal end (34) and proximal end and an inturned flange spaced (40) from the distal end (34) and formed of silicone rubber, the inflation (30) further including a longitudinal teat receiving chamber (32) and a cuff (35), which includes the flange (40) and a spaced wall portion (42), and said shell (12) has a generally cylindrical wall portion (14) with a distal end (16) and proximal end (18) and a peripheral protective wall portion (46) joined with said shell on the outside thereof adjacent the distal end (16), characterised in that said wall portion (46) is spaced from and projects axially beyond said distal end of said inflation (30) and its flange (40), and forms an annular recess (44) which receives the wall portion (42) of the cuff (35), thereby to protect the cuff from damage. An assembly according to claim 1, wherein said protective wall portion (46) is integrally joined with said shell on the outside thereof adjacent to the distal end and flares outwardly beyond said distal end to form an annular frusto-conical, ring-shaped portion receiving the cuff (35). An assembly according to claim 1 or 2, wherein said cuff is received in said annular recess (44) in a sealing press fit.

Inventors: KUPRES, STEVEN J.
Applicants: KUPRES, STEVEN J.
Application year: 1987
Main classification: A01J5
IPC codes: A01J5