NZ204807A - Teat cup claw: valve in each inlet prevents inrush of air when teat cup falls from animal - Google Patents

Description

2Q4SCJ7 NEW ZEALAND Patents Act 1953 N.Z. No.204807 4 July 1983 o SUBSTITUTION OF APPLICANT UNDER SLDTIQM 24 iMo<2r«Ac £K>C\K>£jetjnc UHaen? * ;COMPLETE SPECIFICATION ;A TEAT CUP CLAW ;m 4 OCT 1984 ;RECEIVED ;We, ALPA-LAVAL (N.Z.) LIMITED, a New Zealand company of Sandwich Road, Hamilton, New Zealand, ;do hereby declare the invention for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement ;- 1 - ;204807 ;This invention relates to a teat cup claw. ;Any fall in vacuum in the milk collecting system of machine milking apparatus causes a reverse air flow. A major source of air consumption is during changing of the teat cups from one cow to another and the sudden changes associated with this procedure are of such a nature that they exacerbate the rate of new infections inflicted on the cows involved. Thus, there is a need for a means to reduce the amount of air consumed at the times of cup removal and application. ;A fall in vacuum in the milk collecting system can also cause a reverse flow of potentially infected milk from the claw to the teat cups. This can arise by milk droplets being present in the reverse air flow, these droplets being conveyed during reverse air flow from the claw to the cups. There is therefore also a need for a means to restrict the reverse flow of milk. ;The object of the present invention is to provide a teat cup claw which operates to substantially reduce the amount of air flowing into the machine during teat cup changing. ;According to a broad aspect of the invention there is provided a teat cup claw for machine milking, said teat cup claw comprising a housing having separate milk inlet means each!communicable with the milk chambers of a teat cup, a milk outlet chamber communicable with each of the separate milk inlet means, a plurality of normally biased closed captive valves adapted to seal off the milk inlet means from the milk outlet chamber but responsive to open and allow communication between the inlet means and the outlet chamber when a pressure differential across the valve exists such as when an animal is milked using the claw. ;Preferably the construction and arrangement of each chamber is such that the inlet and outlet are each disposed tangentially to the chamber. ;In the more detailed description of the invention which follows reference will be made to the accompanying drawings in which ;Figure 1 is a largely schematic top plan view of a first form of the teat cup claw according to the invention, ;Figure 2 is a side elevational view of the teat cup claw shown in Figure 1, ;Figures 3a and 3b are more detailed side elevational views of the chamber, valve means, inlet and outlet showing the valve respectively in the open and closed positions, ;Figures 4, 5 and 6 correspond to Figures 1, 2, 3a and 3b but show a second form of the teat cup claw according to the invention, ;Figure 7 is a sectioned elevational view of a commercial form of the teat cup claw according to the invention, ;Figure 8 is a sectioned elevational view of the cam ring arrangement of the claw as shown in Figure 7, and ;Figure 9 is a partial plan view of the cam ring of Figure 8. The teat cup claw 10 is formed by a body 11 which preferably is constructed in three parts, the upper part of which is detachable and provides pulsator connections of the normal alternating pulsation system. In the situation where simultaneous pulsation is required the normal alternating ;20480V ;connector would be replaced by a simultaneous pulsation connector, however, this forms no part of the present invention as will be appreciated by those skilled in the art. ;The central portion of t£e body 11 provides milk inlet connections 13 together with valve chambers 14 and valve mechanism parts 15, 16, 17, 18 and If*- which again are detachable from the lower portion comprising outlet passages 19 and outlet opening 12.

The lower portion of the body 11 of the claw has an outlet opening 12 and this is adapted for fitting to a milk line. This outlet 12-is connected internally to outlet passages 19 with both outlet passages 19 and inlet 13 opening into a chamber 14. As can be seen from the drawings each inlet 13 opens into its own j chamber 14 with outlet passages 19 extending from each chamber 14 to ultimately connect with the outlet connection 12.

Each chamber contains a diaphragm operated valve. The valve in simple terms consists of a valve seating 15 in which there is an opening 15a. A valve member 16 is attached to a valve stem 17 which in turn is attached to a valve diaphragm 18. In the two forms of the invention as illustrated in the drawings the diaphragms 18 are situated externally in the body 11.

Referring primarily to Figures 3a and 3b there is shown the valve in its opened and closed positions respectively and it will be seen that in the closed position the tapered base of the truncated conical valve member 16 is seated within the opening 15a in the valve seating 15. 4 '-s u ^ 204807 The milk inlet connector 13 preferably enters the valve chamber 14 tangentially (as shown in Figures 1 to 6) and milk thus flows with minimum turbulence because of the tangential configuration. When the valve 16 is in the open position as shown in Figure 3a the milk flows with circular motion through the valve port or opening 15a into the outlet portion 14a of the chamber 14. In the preferred form of the invention the outlet passage 19 is also situated tangentially to the chamber as is shown in Figure 3a.

The valve 16 is held in the closed position (Figure 3b) by a spring (not shown) when there is no vacuum in the valve chamber shewn) 14. A by-pass port g&\is provided by a small hole in the valve seat 15 though it can also be provided by a slot^in the valve itself. When a vacuum is applied to the claw the valves remain closed, however, there is a small air flow through the valve by-pass 20. When a teat cup is applied to the teat of an animal the moment the teat seals into the cup the vacuum rises in the vacuum chamber, the operating diaphragm 18 moves under the p ^fc>t>+uj CL<zn OTontoSphfl/"#- tlQCUU/H influence of the pressure differential!across it and so opens the valve thus permitting full flow. In the event of the teat cups falling off or during changing of the teat cups from one animal to another a loss in teat cup vacuum causes an immediate closure of the valve.

The teat cup claw according to the present invention is of such a construction and arrangement that it substantially reduces air flow into the milking machine during cup changing. If a teat ' v J6°CTI987£'! 204807 cup is to fall off during milking vacuum is conserved and air flow into the fallen cup greatly reduced so eliminating the sucking of gross contamination into the cluster.

With the positioning of the inlets 13 and outlets 19 in the tangential manner as illustrated there is a "cyclone action" and therefore droplets in milk entrained in an air stream flowing from the claw to the teat cup are thrown out so greatly reducing the possibility of reverse flow of milk into the teat cup and so reducing the possibility of infection movement. This tangential entry and exit of milk within the valve chambers 14 results in non-turbulent flow which reduces damage caused to the milk by turbulence.

The diaphragms 18 are preferably located so as to be accessable as illustrated and this accessability allows the milker to have an immediate over-riding control of the teat cup vacuum should this be required. Manual depression of the diaphragm immediately opens the valves.

At high liquid flow rates such as occur during cleaning of the milking equipment the cyclone action through the claw results in high velocities of the cleaning liquid against the milk contact surfaces so ensuring good cleaning. eivtrse flow nlnnning t-hr nl nw hnlrinr in »hn hni 1 nntn couac fchc opening flf t-hn nnntrnl iraltiar fo pprmi t-f i ng liquid flow without the action n-f v.-innum.

Referring now to Figure 7 of the drawings there is shown a commercial form of a teat cup claw incorporating the present invention. The claw 10 comprises three body portions which are an upper part 11a which is detachably mounted on central part lib. Upper part 11a is provided with pulsator connections 35 opening into a pulsation chamber 36. A fixture 37 is provided for an anchorage of say a tether which is commonly used to couple the claw to the pneumatic cam of an automatic cluster remover. Detachably mounted to the lower side of the central part lib is a conventionally arranged bowl 11c having the milk outlet connection 12. .

Central body part lib has four chambers 14 into each of which opens an inlet 13 at a downwardly inclined angle. A valve member 16 is positioned within each chamber and seats on a seating formed with chamber outlet 15. Valve member 16 is carried by a valve stem 17 which is coupled to diaphragm 18 by an opening in the diaphragm fitting within a groove in the valve stem 17.

The peripheral edge 18a of diaphragm 18 is located on the upper edge of the chamber wall to be sandwiched between this upper edge and a cup shaped housing 21. The side walls of housing 21 extend upwardly to make contact with upper body part 11a to ensure a sealing pressure is applied to the periphery of diaphragm 18 at the sealing edge 18a. Located within the housing 21 is a spring 23 held in place by a keeper 22. The keeper 22 has a flanged upper portion 24 which fits into a peripheral groove 25 on valve stem 17 and thereby fixes the keeper into position. o r 4 O '• 7 L- ' J . N„ \J I In order to simplify the opening of the valves manually and to make it possible to open the valves simultaneously during cleaning operations a cam ring 27 is incorporated with the upper portion 11a of the claw body. The upper end 26 of each valve stem 17 is slidingly located within an aperture in the top portion of body part 11a to project into a cavity in which the cam ring 27 is located. The cam 27 consists of a body 33 which is rotatably mounted by a central shaft 28 having a threaded lower end 29 engaged in a threaded opening in a centrally located hub 30 in body part lib. A peripheral rim 31 projects from body 33 to engage on the upper surface of the body part 11a surrounding the cavity in which the cam ting 27 is located. Lugs 32 project from the edge of rim 31 and are provided to enable a user of the claw to rotate the cam ring 27.

The interior portion of body 33 includes four cam surfaces 34 each of which engages with the upper end 26 of a respective valve stem 17. When the cam ring 27 is rotated by the lugs 32 the cam surfaces 34 push the valve stems 17 downwardly to simultaneously move the valve members 16 from the seatings around outlets 15. Accordingly when washing of the claw is to take place the cam ring 27 can be rotated to open the valves 16 and thereby permit washing fluid to flow through the claw. The addition of this cam ring 27 thus eliminates the need for a special holder for the cluster assembly during cleaning and makes it possible to clean the cluster system by flushing from a bucket and/or via the reverse flow cleaning method.

O O A C r ~7 t- \J 1 o o7 With the claw construction according to the invention the substantial reduction in the air flow requirements during cup changing decreases the reserve air requirements of the milking machine when the claw is in use. This can lead to a reduction in the size of vacuum regulator required and there are thus consequential decreases in the size of the vacuum pump which greatly reduces the power requirements of the milking machine. The improved vacuum stability makes it possible to reduce the claw volume so reducing reverse liquid flow within the claw.

The invention is open to modification and development within the broad scope of the invention as stated herein. The individual claw chambers for example make it possible to include electrical conductivity cells for the automatic diagnosis of mastitis based on the determination of quarter conductivity r at ios.

^OV-807

Claims (5)

WHAT WE CLAIM IS:

1. A teat cup claw for a milking machine, said teat cup claw comprising a v— stA peChdal'j housing having separate milk inlet means each|communicable with the milk chambers of a teat cup, a milk outlet chamber communicable with each of the separate milk inlet means, a plurality of normally biased closed captive valves adapted to seal off the milk inlet means from the milk outlet chamber but responsive to open and allow communication between the inlet means and the outlet chamber when a pressure differential across the valve exists such as when an animal is milked using the claw.

2. A teat cup claw as claimed in claim 1 wherein the captive valves are stem valves having valve stems and a valve head sealable against a valve face between the inlet means and outlet chambers, each of said valves being tiased into a normally closed position by a biasing spring associated with the valve stem and the housing and an override device co-operative with said valve stems for manually overriding the biasing springs so that the valve members may be held in an open position as required.

A teat cup claw as claimed in claim 2 wherein each inlet means includes an inlet chamber in which the valve members are disposed and free ends of the valve stems of said valve members extend beyond the housing where they are in contact with the override device.

4. A teat cup claw as claimed in any one of claims 1 to 3 wherein the housing comprises three co-operative sections, a first section being a claw bowl, a second section releasably connectable to the claw bowl which houses the individual valve members and a third section which incorporates the o^raride device which is mounted to said second section. w -10- ^C4v 2*14807 r—' c|dl«vi A teat cup claw as claimed imnny nnn nf rlmgnajS fce'-fr wherein the override device is a rotatable member rotatable with respect to the third section of the claw, said rotatable member having cams contactable with said free ends of the valve stems on rotation thereof. r— etaitv> -4" 0<~ C.\a\rv\ £ A teat cup claw as claimed in\nny nnn nf nlniflnn 7 tn

5. whfirpin the third section of the claw incorporates ajpjuooticfi air inlet and a series of outlets connectable to the pulsation chambers of a set of teat cups. A teat cup claw as claimed in any one of claims 2 to 6 wherein the valve members each mount a spring keeper and the biasing of the valve into a normally closed position is achieved by applying each spring between the spring keeper and a co-axial keeper plate fixed relative to the housing. 4U~! A teat cup claw as claimed in any one of claims^X tu 7. wherein the stem of each valve mounts a diaphragm sealing off the second section with respect to the third section. A teat cup claw substantially as herein described with reference to the accompanying drawings. o' //'V : NORTRAC ENGINEERING LIMITED by their Attorneys BARRY V. JAMES & ASSOCIATES.