GB2179231A - Improvements in or relating to teat cups and teat cup liners - Google Patents

Abstract

A teat cup for automatic milking apparatus, particularly for hydraulic milking, using a teat cup liner with a mouthpiece having a roll-over inner edge. The mouthpiece presents a smooth, vacuum-sealing surface to the cow teat in the milking position and a vacuum-release, configured surface (grooves 16') in the teat cup removal position. <IMAGE>

Description

SPECIFICATION Improvements in or relating to teat cups and teat cup liners Background of the Invention This invention relates to teat cups and more particularly to teat cup liners for use in automatic milking apparatus.

Automatic milking apparatus includes, for each cow milking unit, a clawpiece and a cluster of four teat cups connected to the clawpiece by short milk tubes.

For milking, the fourteat cups are placed around the cow's teats and are held in position during the milking operation by adhesion, due to the vacuum applied for the milking operation.

In conventional milking methods, in which a continuous air bleed is provided at, or upstream of, the clawpiece, this vacuum-induced adhesion is automatically broken, when the milking operation stops, so that the teat cup cluster is easily removed from the milked cow.

However, a more modern milking method, known as the hydraulic milking method, has been introduced in which there is no air bleed at, or upstream of, the clawpiece and in consequence the vacuum-induced adhesion is not automatically broken after milking, so that the teat cup cluster is more difficult to remove from the milked cow.

The object of the present invention is to provide teat cups with an improved liner which facilitates removal of the teat cup cluster after milking by the hydraulic milking method.

Short Description of the Drawings The principle of the invention and embodiments thereof will be described in detail, the embodiments being by way of example, with reference to the accompanying drawings, in which: Fig. lisa diagram showing two teat cups of a cluster in position for milking and showing particularly the liner mouthpiece profile during milking; Fig. 2 is a diagram, corresponding to that of Fig. 1, showing particularly the liner mouthpiece profile after milking, at the time of removal;; Figs. 3,4 and 5, Figs. 6,7 and 8, and Figs. 9, 10 and 11 are three sets of three diagrams, each set showing a teat cup liner mouthpiece of different cross-section and the three diagrams of each set showing the liner mouthpiece internal lip in three different positions corresponding respectively to the rest position, the milking position and the removal position; Fig. 12 is an underside view of a liner mouthpiece of preferred cross-section; and Fig. 13 is elevation view of the same liner cut along the section lines 13S13 of Fig. 12.

Description of the Embodiment Known automatic milking apparatus includes, for each cow milking unit, a clawpiece and a cluster of four teat cups connected to the clawpiece by four short miiktubes and reference will be made to Fig. 1 to describe the known construction and manner of operation of the teat cups, since the construction of teat cup according to the invention follows the known construction i. most respects.

In Fig. 1 and Fig. 2, a cow udder is shown at 1 and two teats at 2, two teat cups being shown at 3. Each teat cup 3 has a rigid shell 4 and a teat cup liner 5.

The liner 5 is a flexible, moulded member which fits into and seals onto the upper lip of the shell 4.

Usually, as shown, the short milk tube 6 is moulded integrally with the teat cup liner 5. The teat cup liner itself comprises a barrel 7 and a mouthpiece 8. The liner mouthpiece 8 is positioned above the shell 4 and the liner barrel 7 lies within the shell 4 leaving an annular space 9 between the shell inner wall and the barrel outer face.

The liner mouthpiece 8 is a circular apertured membrane extending inwardly from the top of the upper wall part 10 of the liner 5.

For milking, the teat cups 3 are fitted over the teats 2 as shown in Fig. 1 and Fig. 2. During milking, vacuum pressure and atmospheric pressure are applied alternately to the annular space 9, by way of a line connected to the teat cup shell 4, not shown in the drawings. The short milktube 6 also conveys vacuum pressure from the clawpiece to the interior space of the liner 5 below and around the teat 2.

In the conventional milking systems, having a continuous air bleed into that part of the system between the liner mouthpiece 8 and the clawpiece, the vacuum in the liner interior space is lost when the milking operation stops and the teat cup 3 cluster is readily removed from the teats 2 of the milked cow.

In a milking system such as that described in copending patent application No. 8512941,wherein no air bleed is permitted into the system up-stream of the clawpiece, the vacuum in the liner interior space is not lost and the teat cup cluster is not readily removable from the teats of the milked cow.

We now continue with the description of the accompanying drawings in the context of the present invention.

In Fig. 1,which corresponds to the fitting of the teat cup cluster and to the milking condition, it will be noted that the inner edge of the mouthpiece 8 aperture is turned downwardly against the side of the teat 2. This disposition is due, initially, to the motion of the teat cup, when being fitted, in the upward direction of arrow 11. During milking, it is retained in the same position by the vacuum within the interior space of the liner 5.

Referring, now, to Fig. 2, the initial motion of removal, in the downward direction of arrow 12, causes the inner edge of the mouthpiece aperture to roll over on the teat surface until the diaphragm is turned upwardly.

There are two requirements of a teat cup liner in accordance with the invention. The first is that the configuration of the mouthpiece diaphragm is such that this rolling over of the inner edge takes place upon initial downward motion of the teat cup. The second is that when the teat cup liner diaphragm is flexed downwardly, as shown in Fig. 1, the surface it presents to the teat surface is such as to maintain a seal therewith, whereas, when the teat cup liner diaphragm is flexed upwardly, as shown in Fig. 2, the surface is presents to the teat surface is such as to permit air to leak into the teat cup liner interior.

This feature is illustrated more clearly with reference to Figs. 3 to 11. Figs. 3--5 show in cross section one side of a conventional teat cup liner 5, showing part of the upper wall part 10 and one half of the diaphragm 13 extending inwardly to form the aperture of the mouthpiece 8. Fig. 3 shows the tapered section of the diaphragm 13 to the inner aperture face 14 and further shows the disposition of the diaphragm when the teat cup is not fitted onto a teat. Fig. 4 shows the downwardly turned disposition of the diaphragm when the teat cup is fitted, the teat face being shown at 2. This is also the disposition during milking.

Fig. 5 shows the upwardly turned disposition of the diaphragm when the teat cup is urged downwardly.

Figs. 4 and 5 are to be compared with Figs. 1 and 2, respectively. It is particularly to be noted that with this known cross section of diaphragm 13, tapering to the aperture face 14, the teat cup liner mouthpiece seals with the teat surface 2 in both the dispositions shown in Fig. 4 and Fig. 5.

Figs. 68 show the corresponding view of a teat cup liner according to the invention, the mouthpiece diaphragm 13 of which has an inner rounded portion 15, which presents the aperture face to the teat surface 2. A downwardly and inwardly inclined circular area 16 of the aperture face has a series of grooves provided therein which extend in the direction of the broken line 16'.

In corresponding manner to Figs. 3--5, Fig. 6 shows the diaphragm 13 disposition when the teat cup is free from a teat. Fig. 7 shows the diaphragm 13 disposition when the teat cup is fitted and Fig. 8 shows the diaphragm 13 disposition when the teat cup is urged downwardly for removal.

It is particularly to be noted in Fig. 7 that the plain aperture surface of the rounded portion 15 is presented to the teat surface and a good seal is formed and maintained during milking. However, in the disposition shown in Fig. 8, the grooved area 16 of the aperture face is presented to the teat surface 2. Air passes downwardly through the grooves into the interior of the teat cup liner and the vacuum seal is broken. The teat cup cluster can then be easily removed.

Figs. 9--11 show a preferred teat cup liner having a different mouthpiece diaphragm cross-section from that shown in Figs. 6--8. However, the manner of functioning is the same.

As seen in Fig. 9, the diaphragm 13 extends inwardlyto an enlarged rounded portion 15 at the mouthpiece aperture. However, the diaphragm thickness is reduced between the underside 17 and the top face 18, to facilitate the flexing of the inner portion 15 into the positions shown in Fig. 10 and Fig. 11. Fig. 10 shows the disposition of the portion 15 when the teat cup is fitted and during milking.

Fig. 11 shows the disposition of the portion 15 when the teat cup is urged downwardly for removal.

In similar manner to that shown in Fig. 7, Fig. 10 shows a sealing face of the portion 15 presented to the teat surface 2. Fig. 11 shows the grooved portion 16 in contact with the teat surface, so permitting air to pass into the teat cup liner interior and the easy removal of the teat cups.

The preferred cross section of the inner portion 15 provides a narrow contact ring between the mouthpiece aperture and the teat surface, which assists the making and maintaining of a good seal during milking.

Figs. 12 and 13 show different views of the embodiment described with reference to Figs. 9--11. Fig. 12 is the view, looking upwards, of the underside of the diaphragm 13 of Fig. 9. The upper wall part 10 is seen as an outer ring in the view of Fig. 12. The underside of the liner mouthpiece is seen at 13. In the views of Fig. 9 and Fig. 12, the grooves 16' form a circular surface 16 which is downwardly and inwardly inclined to the axis of the teat cup liner.

Fig. 13, which is an angled section on the line 13--00-13 of Fig. 12, shows two section views of the diaphragm 13 and shows the grooves 16' in elevation.

Claims (9)

1. A teat cup liner, for automatic milking apparatus and particularly for hydraulic milking, having a mouthpiece with a radial cross-section such that a roll-over action of the inner edge is produced as the said liner is urged for removal from a cow teat, the said inner edge providing a vacuumsealing surface for contacting the cow teat during milking and a configured, vacuum-releasing surface presented in consequence of the said roll-over action.

2. A teat cup liner as claimed in Claim 1, in which the mouthpiece has an enlarged and rounded inner edge to promote the said roll-over action.

3. A teat cup liner as claimed in Claim 2 in which the mouthpiece has a smooth surface for contacting the cow teat during milking and a grooved surface positioned at the said inner edge for being brought into contact with the cow teat by the said roll-over action.

4. A teat cup liner as claimed in Claim 2, in which the said mouthpiece is central of a diaphragm having a circular region, of smaller thickness than the said diaphragm, and immediately surrounding the said enlarged and rounded inner edge, for the purpose of facilitating the said roll-over action.

5. A teat cup liner as claimed in Claim 3, in which the said inner edge is peaked in the region of the said smooth surface, to provide a narrow cow-teat contacting region.

6. A teat cup liner as claimed in Claim 1, formed substantially as described herein with reference to Figs. 6,7 and 8, Figs. 9, 10 and 11 or Figs. 12 and 13 ofthe accompanying drawings.

7. A teat cup having a teat cup liner as claimed in any one of the preceding claims.

8. A method of hydraulic milking employing automatic milking apparatus with a cluster of teat cups as claimed in Claim 7.

9. A method of hydraulic milking as claimed in Claim 8, including the step, after milking, of withdrawing the teat cup cluster from the cow teats thereby to bring about the said roll-over action of the liner inner edges and consequent vacuumrelease of the teat cup cluster.