GB2144019A

GB2144019A - Vaccum pulsator valves

Info

Publication number: GB2144019A
Application number: GB08401451A
Authority: GB
Inventors: Thomas Leslie Seaborne
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-02-13
Filing date: 1984-01-19
Publication date: 1985-02-27
Also published as: GB8401451D0; GB2094126B; NZ199721A; GB2094126A; GB2144019B

Description

1 GB 2 144 01 9A 1

SPECIFICATION

Vacuum pulsator units The present invention relates to vacuum operated pulsator units for milking machines and in particular apparatus for relying a pulse from a master pulsator unit to a slave pulsator unit or from one slave pulsator unit to a subsequent slave pulsator unit. The present invention is divided from co- pending United Kingdom Patent Application No. 82.04342 (Publication Number 2 094 126A) which describes and claims a novel pulsator unit for use with milking machines.

With the trend to more rapid rates of pulsation and increased vacuum to atmospheric air ratios to promote faster milking of the herd, the time factor in pulsation for the introduc- tion of atmospheric air giving pressure to the teat cups has become shorter thus reducing cow comfort.

In all known pneumatic relay pulsators controlled by an automatic master the passing of pulsation phases one to the other has only been effectively accomplished when the pulses passed were of an equal ratio. In the circumstances where a master or a relay pulsator produces an operating pulse where the vacuum phase is greater than that of atmospheric pressure such as a vacuum/air ratio of 60:40, then this pulse would, if passed directly to the actuating chamber of the next pulsator, produce to the connected teat cups of that reversed vacuum/air ratio of 40:60.

There is no known milking machine valve capable of correcting this effect and enable in such pulsation the passing one to the other of any desired constant ratio.

Accordingly the present invention provides a vacuum pulsator unit adapted to supply pulses of vacuum alternately with pulses of atmospheric or compressed air, said pulsator comprising a body including means for connecting a first zone of said body to a permanent vacuum source and a diaphragm valve comprising a first valve element co-operating with a first valve seat adapted to connect a second zone of said body to a source of atmospheric or compressed air, said body further including a second valve seat adapted to be opened or closed to establish or prevent communication between said first and second zones, said body further housing a first defor- mable diaphragm having first and second opposed surfaces with said first surface arranged for exposure to said permanent vacuum source and co- operating with said first valve element whereby said first valve element is movable such that when said second valve seat is closed, said first valve seat is open thereby applying atmospheric or compressed air to said second zone, and when said second valve seat is open, said first valve seat is closed thereby applying vacuum to said sec- ond zone, and relay valve control means arranged to communicate the second zone of said pulsator either with the second surface of said first deformable diaphragm of the pulsa- tor of an adjacent pulsator, said communication occurring via a non return valve and an adjustable valve means arranged in parallel flow relation.

The invention will now be described with reference to preferred embodiments iilustrated in the accompanying drawings in which:

Figure 1 is a sectional view of a relay pulsator taken on line 111-111 of Figure 3; Figure 2 is a sectional view of a relay valve means taken on line VII-VII of Figure 3; Figure 3 is a plan view of the relay pulsator shown in Figure 1; Figure 4 is a sectional view of the relay pulsator taken along line Vill-VIII of Figure 3; Figure 5 is a sectional view of a pressure member taken on line IX-IX of Figure 6; and Figure 6 is a plan view of the pressure member shown in Figure 5.

Referring to the drawings, the construction of the relay pulsator unit is essentially similar to the automatic or master pulsator unit shown in the published British Patent Application No. 2 094 126A except that the timing chamber is replaced by a pulsator cap 50 which has preferably a nozzle connection 49 giving access to an actuating chamber 51 and a relay/ratio adjustment valve 37a is added as a combined entity. The fabricated housing includes the actuating chamber 51, a body 2 and a base 3 having a permanent connection to vacuum 4, and a connection 5, to the milking machine teat cups.

A diaphragm 6, is located in the section between the chamber 51 and the body 2 is sealed by the pulsator cap 50. There is further provided an annular seat 76, and a pressure member 8 is interposed in the chamber between the connection to vacuum 4 and the connection to teat cups 5. The pressure mem- ber 8 is slidable in the guide 9 immediately above the seat 7. The pressure member 8 is arranged to be in contact with both the diaphragm 6, and the central annular seat 7.

The lower section of the pressure member 8 also acts as a valve member in contact with a valve diaphragm 10 located in the base 3 of the pulsator 3 functioning to operate immediately the pressure member 8 is moved down under atmospheric pressure on the diaphragm 6 so as to prevent direct passage of atmospheric air to the vacuum connection during the changing phases of the pulsator from air, or from vacuum to the teat cups. The valve diaphragm 10 also co-acts with a seat 11 located in the base 3 for admitting atmospheric air to the teat cups through connection 5.

The base 3 is circular in shape and has four holes 12 arranged centrally to allow admit- tance of atmospheric air to the pulsator. Provi- 2 sion is made at 13 for the attachment of a suitable air filter. Alternatively the air admission holes 12 may be plugged off or omitted and replaced by a suitable connection giving 5 the pulsator access to compressed air.

Around the holes 12 is arranged a ring or seat 11 and adjacent thereto are arranged metering holes 14 enabling atmospheric air to pass to the teat cups through the connection 5. Sitting across the seat 11 is the valve diaphragm 10 held in place by a suitably fixed retaining plate 15 which has a central aperture 16 extending just clear of the outer periphery of the seat 11 allowing access to the contacting valve head of the pressure medium 8. Adjacent to the aperture 16 the retaining plate has a circular recess 17. The object of this recess is to allow the valve diaphragm to have minimal or no clearance across the seat 11 so that the entry of atmospheric air to the pulsator under pulsation is only possible on the air phase to cups, thus creating a positive and leak proof pulsator under all conditions of operation.

When a vacuum phase pertains to the pul- sator the recess 17 operates in conjunction with a projection 8b and a recess 8c of the pressure member 8 to give clearance across the seat 11, thus allowing atmospheric air to pass to the teat cups.

The sliding valve or pressure member 8 is of particular shape. A guide system 8a is fluted or grooved to both reduce friction and give free passage of atmospheric air via the fluted air passages 8 d from teat cups to 100 permanent vacuum.

The lower section which operates in perma nent contact with the valve diaphragm 10 is stepped in shape having a circular projection 8b and a circular recess 8c.

The action of which is as follows:

1. On atmosphere applied across the dia phragm 6 the resultant initial downward movement of the pressure member 8 causes the small projection 8b acting centrally on the valve diaphragm 10 to immediately close off atmospheric air across the seat 11. The fur ther downward movement continuing until stopped by the recess 8c acting across the seat 11 thus providing accurate opening of the seat 7 to permanent vacuum.

2. On vacuum applied across the dia phragm 6 atmospheric air entering through the holes 12 against the valve diaphragm 10 forces the pressure member 8 upwards to instantly close off permanent vacuum at the seat 7, and at the same time forces and distorts the valve diaphragm 10 around the projection 8b into the recess 8c and across into the recess 17 of the retaining plate 15, thus giving full clearance above the seat 11 and allowing atmospheric or compressed air to pass to the teat cups via the air metering holes 14 and connection to teat cups 5.

The pulsator unit as described in the forego- 130 GB 2 144 019A 2 ing may have rate or ratio control means applied to it as described in copending published Patent Application No. 2 094 126A.

The description of the relay facility will now be made with reference to the accompanying drawings. The pulsator unit illustrated in the accompanying drawings show a valve housing 37a attached to the pulsator body 2. The valve housing 37a is preferably oblong in shape and is constructed with two main air passages 38 and 39.

Referring to Figures 1 and 2 when atmospheric air pertains to the valve via the connection 47 air flows through passage 38 and via a ball valve 40 lifted thereby, common channel 46 and via channel 45, the needle valve 43, passage 39, chamber 46, through a connecting nozzle 48 to a nozzle 49 giving access through the pulsator cap 50 to the actuating chamber 51 of the driven pulsator to provide free and rapid action of the dia phragm 6. The airflow or pulse thus passed causes a resultant instant vacuum pulse to the teat cups of the d6ven pulsator.

Conversely, when vacuum pertains to the valve, air being withdrawn immediately closes the ball valve 40 thus compelling all air to pass via passage 39, the adjusting needle valve 43, channel 45, passage 38 to the connection to vacuum 4/. Vacuum now pertaining to the actuating chamber of the driven pulsator causes atmosphere to pertain to the attached teat cups.

To lengthen the vacuum-to-teat cups phase the withdrawal of air is restricted by closing the ratio needle valve 43 thus prolonging the air pnase to the actuating chamber to the desired ratio.

To shorten the vacuum-to-teat cups phase the ratio needle valve is opened thus accelerating the withdrawal of air from the actuating chamber.

Claims

1. A vacuum pulsator unit adapted to supply pulses of vacuum alternately with pulses of atmospheric or compressed air, said pulsator comprising a body including means for connecting a first zone of said body to a permanent vacuum source and a diaphragm valve comprising a first valve element cooperating with a first valve seat adapted to connect a second zone of said body to a source of atmospheric or compressed air, said body further including a second valve seat adaptcad to be opened or closed to establish or prever,t communication between said first and second 7ories, said body further housing a first deformable diaphragm having first and second opposed surfaces with said first surface arranged for exposure to said permanent vacuum source and co-operating with said first valve element whereby said first valve element is mcva0e such that when said secand valve seat is closed, said first valve seat is 3 GB 2 144 01 9A 3 open thereby applying atmospheric or compressed air to said second zone, and when said second valve seat is open, said first valve seat is closed thereby applying vacuum to said second zone, and relay valve control means arranged to communicate the second zone of said pulsator either with the second surface of said first deformable diaphragm of the pulsator or an adjacent pulsator, said communication occurring via a non return valve and an adjustable valve means arranged in parallel flow relation.

2. A vacuum pulsator according to claim 1, wherein said first valve element comprises a second deformable diaphragm secured to said body.

3. A vacuum pulsator according to claim 2, further including a movable valve member interposed between and co-operating with said second deformable diaphragm and said first deformable diaphragm, said valve member including a seal surface adapted to engage against said second valve seat to close said second valve seat.

4. A vacuum pulsator according to claim 3, wherein said second valve seat is closed prior to said second diaphragm opening said first valve seat and said second diaphragm closes said first valve seat prior to said second valve seat opening.

5. A vacuum pulsator according to claim 4, wherein said valve member includes a projection adapted to engage and press said second deformable diaphragm against said first valve seat prior to engagement of a second portion of said valve member pressing against said second deformable diaphragm on said first valve seat.

6. A vacuum pulsator according to claim 3, 4 or 5, wherein when said valve member is engaged against said second valve seat, a clearance zone is formed above said first valve seat into which said second diaphragm is deformable under action of vacuum in said second zone to open said first valve seat permitting atmospheric or compressed air to flow into said second zone.

7. A vacuum pulsator according to any one of the preceding claims, wherein said relay valve control means comprises a body having an inlet passage communicating with the second zone of said pulsator, said inlet passage communicating via the non return valve with an outlet passage which is adapted for com- munication with the second surface of the first deformable diaphragm of the pulsator to which the relay valve control means is connected or to the second surface of a second deformable diaphragm of an adjacent pulsa- tor, said relay valve control means further including a branch passage leading from said inlet passage to said outlet passage, flow through said branch passage being controlled by an adjustable valve element.

8. A vacuum pulsator unit having relay valve control means substantially as herein described with reference to the accompanying drawings.

Printed in the United Kingdom for Her Majesty's Stationery Office, Dd 8818935, 1985, 4235. Published at The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.