TEAT CUP INFLATION

Abstract: A teat cup inflation (39) comprises a flexible tubular member having upper (UB) and lower (LB) barrels and a mouthpiece chamber (MC). The walls of the upper and lower barrels (UB,LB) are formed as continuous bands of alternating internal and external flutes (45,47). The lower end of the lower barrel (LB) is formed with an external projection (61) that is received in a groove (15) in a teat cup shell (3). The wall of the inflation upper barrel (UB) diverges from the lower barrel (LB) toward the mouthpiece chamber (MC). The wall of a portion of the mouthpiece chamber (MC) is fluted on the interior and has a frusto-conical surface (51) on the exterior. The mouthpiece chamber (MC) further has a band portion (53) that receives a retaining ring (35) for assembling the inflation (39) in the teat cup (1) without tools and without stressing the inflation mouthpiece (57) after assembly. The inflation (39) provides better control for teat penetration for improved milkout.

Description: This invention pertains to dairy equipment, and more particularly to apparatus for milking dairy cows. Various equipment has been developed to assist dairymen increase the efficiency of their operations. For example, machines for milking cows are well known. A vital component of modern milking machines is the teat cup, which fits over the cow's teat during milking. The teat cup includes a hollow flexible inflation that contacts the teat. Under the action of a vacuum system, the inflation massages the teat to maintain circulation while vacuum expresses milk from the cow into a milk line. Some examples of known teat cup inflations are described in DE-U-6806597, US-A-4269143 and US-A-4,530, 307. The inflation described in US-A-4,530,307 comprises a generally tubular member according to the first part of claim 1, having a longitudinal axis and a wall formed as a continuous band of alternating exterior and interior flutes, a portion of the tubular member at its upper end defining a mouthpiece chamber. During operation, the flutes produce a uniform distribution of forces around the cow's teat, and enable the inflation to provide uniform massaging without pinching the teat, and to accommodate a variety of teat sizes and shapes. Because of its beneficial qualities, the inflation of the US-A-4,530,307 has enjoyed considerable commercial success. Nevertheless, ongoing research and development indicates that further improvements in inflations are desirable and the present invention provides a new teat cup inflation that surpasses the performance of prior inflations. According to the invention there is provided an inflation for a teat cup of a milking apparatus, comprising a flexible, generally tubular member having a longitudinal axis and a wall with first and second ends, the tubular member having a lower barrel adjacent the first end, a mouthpiece chamber adjacent the second end, and an upper barrel intermediate the lower barrel and the mouthpiece chamber, the wall of the tubular member upper and lower barrels being formed as a continuous band of alternating exterior and interior flutes, the exterior flutes lying within an envelope of predetermined diameter, characterised in that a predetermined length of the wall of the tubular member mouthpiece chamber has flutes only on its interior surface, and the corresponding exterior surface is formed as a frusto-conical surface. This arrangement results in an unusually rigid and stable construction for the mouthpiece chamber. The improved design prevents the flutes at the mouthpiece chamber from unfolding in use, which would allow excessive teat penetration into the inflation and prevent complete milkout of the cow. Preferably the wall of the tubular member lower barrel is generally parallel to the longitudinal axis, and the wall of the tubular member upper barrel diverges in the direction of the wall second end to thereby form a taper in the upper barrel. The tapered upper barrel further contributes to better control of teat penetration into the inflation and thus better milkout. Preferably the tubular member comprises a projection extending radially outwardly from its wall at the first end thereof, the projection having an outer diameter greater than the envelope of the exterior flutes on the tubular member lower barrel. The projection is arranged to mate with a groove in the teat cup to hold the inflation in place during assembly of the various teat cup components prior to use in the milking operation. It is a further preferred feature of the present invention that the mouthpiece chamber is preformed to receive a ring for retaining the inflation in the teat cup. This design allows the inflation to be inserted into the teat cup in an unstressed condition and without the use of any tools. Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention. One embodiment of an inflation in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a longitudinal cross-sectional view of the embodiment of an inflation according to the present invention inserted into a teat cup. Fig. 2 is an enlarged cross-sectional view taken along lines 2-2 of Fig. 1. Fig. 3 is an enlarged view of the lower end of the inflation in an unassembled condition. Fig. 4 is an enlarged cross-sectional view taken along lines 4-4 of Fig. 1. Referring to Fig. 1, a teat cup 1 is illustrated that includes the present invention. The teat cup 1 is particularly useful for placing over a teat of a cow's udder for milking the cow by machine. The teat cup 1 comprises a central shell 3, an upper shell 5, a retainer 6, and an end cap 7. The central shell 3 is generally shaped as a tubular cylinder having a wall 8 with an upper section 9 and a lower section 11. The central shell lower section 11 has external threads 13 and an external groove 15 located between the threads 13 and the central shell lower end 17. The central shell further comprises a vacuum tube 19 that is joined to and opens into the interior of the tubular wall 8. The wall 8 defines a series of external annular grooves 21 in the upper section 9 and a keyway 23 that extends from the shell upper end 25 to the grooves 21. The upper shell 5 is a hollow cylinder having a wall 26 and an annular flange 27 extending radially from its upper end. The lower end 28 of the upper shell is formed with an internal chamfer 29. The upper shell cylinder wall 26 also has an inwardly projecting lug 30 between the flange 27 and the lower end 28. The teat cup end cap 7 has an upper end with internal threads that mate with the central shell threads 13. The cap lower end is formed with a connection tip 33. The central shell 3 and the cap 7 are fabricated from a transparent plastic. The upper shell 5 is fabricated from stainless steel. The retainer 6 is preferably manufactured from a molded rubber material. The retainer has a first internal groove 35 that conforms to the flange 27 of the upper shell 5. The retainer also has a second internal groove 37. In accordance with the present invention, the improved inflation 39 is inserted into the teat cup 1 for providing increased performance to a milking machine system. The inflation 39 is fabricated generally as an elongated tubular member having a wall 40 that is concentric about a longitudinal axis 42. The inflation is divided into a lower barrel LB, and upper barrel UB, and a mouthpiece chamber MC. Looking also at Fig. 2, the inflation lower barrel LB extends from the inflation lower end 39 to approximately the longitudinal midpoint 49. The inflation wall 40 of the lower barrel is formed with a cross-section in the form of a continuous band of alternating and parallel external flutes 45 and internal flutes 47. In its unassembled condition, the lower barrel cross-section is substantially constant, and the flutes 45 and 47 are parallel to the axis 42. The portion of the inflation 40 between the midpoint 49 thereof and the inflation upper end 43 is divided into the upper barrel UB and the mouthpiece chamber MC. For the length of the upper barrel, the wall 40 is defined by flutes 45 and 47 that are continuations of the respective flutes on the inflation lower barrel LB. However, the wall 40 of the upper barrel gradually diverges toward the inflation upper end 43 so as to impart a taper to the upper barrel. From its junction with the upper barrel UB, the wall 40 of the inflation mouthpiece chamber MC continues to diverge toward the inflation upper end 43. In addition, the cross-section of the wall at the mouthpiece chamber is different than at the upper barrel and at the lower barrel LB. As further shown in Fig. 4, the inflation wall for a length F of the mouthpiece chamber is fabricated only with internal flutes 47. The corresponding exterior surface of the inflation wall is formed without exterior flutes but rather as a frusto-conical surface 51. From the upper end of the length F of the mouthpiece chamber MC, the inflation wall 40 blends into an annular band 53 of material. The band 53 defines an inner diameter sized to the same dimension as the outer diameter of a retaining ring 55 plus a band of metal 53. A washer-like mouthpiece 57 having an internal surface 59 connects to the mouthpiece chamber band 53. Further in accordance with the present invention, the inflation lower end 41 is formed with an outwardly extending annular projection 61. Also see Fig. 3. The outer diameter of the projection 61 is larger than the envelope 62 of the inflation external flutes 45. The inflation 39 is made from a flexible elastomer. While silicon rubber is a preferred material, other elastomers are also acceptable. A thickness of approximately .08 inches (2.03mm) for the inflation wall 40 works very well. To assemble and use the teat cup 1, the retainer 6 is pressed onto the upper shell 5 such that the upper shell flange 27 engages the first groove 35 of the retainer. The retaining ring 55 is installed in the inner diameter of the inflation band 53. The fact that the inflation band is pre-sized to the outer diameter of the retaining ring 55 eliminates the requirement of a special tool for installing the retaining ring, as was necessary with prior inflations. Then the upper shell 5 is pushed onto the central shell, with the upper shell lug 30 engaging the central shell keyway 23. Then the inflation lower end 41 is inserted through the assembled upper shell and retainer, and the inflation mouthpiece chamber band 53 is seated in the retainer second groove 37. The lower end 41 of the inflation 39 is folded outwardly to curl around the lower end 17 of the central shell 3. The inflation projection 61 is designed to fit within the groove 15 near the lower end of the central shell. The cap 7 is screwed onto the central shell by means of the threads 13 on the central shell and cooperating internal threads on the cap. The upper shell is pushed up the central shell, stretching the inflation, and the sealing ring 63 is installed in a selected groove 21 of the central shell 3. In operation, a flexible hose, not shown, is connected to the teat cup tip 33, and a steady vacuum is applied to the hose. The mouthpiece internal surface 59 of the inflation 39 is slipped over a cow's teat such that the teat enters the mouthpiece chamber MC and upper barrel UB. The vacuum induced in the interior of the inflation through the tip 33 causes atmospheric pressure to collapse the inflation upper barrel slightly around the teat to hold the inflation and thus the teat cup in place. A second hose, also not illustrated, is connected to the vacuum tube 19 of the central shell 3. A pulsating vacuum is applied to the vacuum tube 19 and thus to the interior of the central shell 3 and to the exterior of the inflation 39. As a result, the inflation upper barrel UB and lower barrel LB alternately expand and collapse radially about axis 42 in a continuous manner, the vacuum causing the teat to express milk into the interior of the inflation and out the tip 33, and the collapse massaging the teat end, thereby preventing tissue damage which a constant vacuum would produce. The unique construction of the inflation 39 that combines flutes 45 on the interior and the frusto-conical surface 51 on the exterior of the mouthpiece chamber MC for the length F thereof results in several advantages. The inflation wall 40 is unusually rigid and stable in that region. The wall rigidity prevents the flutes from unfolding and thus increasing the effective diameter of the upper barrel and mouthpiece chamber, which would allow the cow's teat to penetrate further into the inflation than is desirable and thereby prevent complete milkout of the cow. The preformed diameter of the inflation mouthpiece chamber band 53 allows the retaining ring 55 to be installed without tools. Moreover, the preformed inflation band 53 predetermines the diameter of the mouthpiece internal surface 59 for consistency between inflations and also allows the mouthpiece chamber to be in an unstressed condition when the inflation is assembled in the teat cup 1. The projection 61 on the lower end 41 of the inflation 39 mates with and is held in place in the central shell groove 15. That feature simplifies assembly of the cap 7 to the other teat cup components. Further, of course, the new inflation of the present invention retains all the advantages of prior fluted inflations.

Claims: An inflation (39) for a teat cup of a milking apparatus, comprising a flexible, generally tubular member having a longitudinal axis (42) and a wall (40) with first and second ends, the tubular member having a lower barrel (LB) adjacent the first end, a mouthpiece chamber (MC) adjacent the second end, and an upper barrel (UB) intermediate the lower barrel (LB) and the mouthpiece chamber (MC), the wall of the tubular member upper and lower barrels being formed as a continuous band of alternating exterior (45) and interior (47) flutes, the exterior flutes (45) lying within an envelope of predetermined diameter, characterised in that a predetermined length (F) of the wall (40) of the tubular member mouthpiece chamber (MC) has flutes (47) only on its interior surface, and the corresponding exterior surface is formed as a frusto-conical surface (51). An inflation according to claim 1, wherein the wall (40) of the tubular member lower barrel (LB) is generally parallel to the longitudinal axis (42), and the wall (40) of the tubular member upper barrel (UB) diverges in the direction of the wall second end to thereby form a taper in the upper barrel (UB). An inflation according to claim 1, wherein the tubular member comprises a projection (61) extending radially outwardly from its wall (40) at the first end thereof, the projection having an outer diameter greater than the envelope of the exterior flutes (45) on the tubular member lower barrel (LB). An inflation according to claim 1, wherein the inflation (39) is made of a silicon rubber elastomer, and wherein the thickness of the tubular member wall of the upper barrel and the lower barrel is aproximately .08 inches (2.03mm). An inflation according to claim 1, wherein the upper barrel (UB) diverges gradually from the lower barrel (LB) in a direction towards the wall second end, and the mouthpiece chamber (MC) diverges from the upper barrel (UB). An inflation according to any one of the preceding claims, wherein the flutes (47) formed on the interior surface of the mouthpiece chamber (MC) are continuations of respective interior flutes on the upper barrel (UB), and a mouthpiece (57) is provided at the second end of the tubular member wall (40) concentric with the longitudinal axis (42) thereof. Apparatus for milking cows comprising: a) a teat cup (1) comprising a tubular central shell (3) having upper and lower ends and defining an external groove (15) at its lower end, a tubular upper shell (5) coupled to the upper end of the central shell (3), a tubular retainer (6) coupled to the upper shell and having an internal groove (35) of a predetermined diameter, and a tubular cap (7) coupled to the lower end of the central shell (3); b) an inflation (39) according to any one of the preceding claims fitted into the teat cup (1) so that the first end of the tubular member wall (40) extends beyond the lower end of the central shell (3), the wall of the mouthpiece chamber (MC) having a portion which is disposed between the wall second end and said predetermined length having flutes (47) on its interior surface and which defines an annular band (53) that fits within the internal groove (37) of the teat cup retainer; and, c) a retaining ring (55) installed within the mouthpiece chamber (MC) against the annular band (53) in the internal groove (37) to retain the inflation (39) in the teat cup (1). Apparatus according to claim 7, wherein the mouthpiece chamber band (53) has an internal diameter pre-sized to enable the retaining ring (55) to be installed therein without tools and with the inflation (39) in an unstressed condition after assembly. Apparatus according to claim 7 when dependent on claim 3, wherein the projection (61) extending radially from the first end of the tubular member wall (40) extends around the lower end of the central shell (3) of the teat cup (1) and is received in the groove (15) at the central shell lower end to hold the lower barrel (LB) of the inflation in place in the teat cup (1).

Inventors: STEINGRABER, GARY C., THOMPSON, PAUL D.
Applicants: DEC INTERNATIONAL, INC.
Application year: 1990
Main classification: A01J5
IPC codes: A01J5