GB2098847A - Vacuum milking equipment - Google Patents

Abstract

Vacuum milking equipment, for use in milking sheep and goats, comprises a housing (5) with a milk collecting chamber (6) and a control chamber (15). A diaphragm (11) bounds the control chamber (15) and is coupled by a rod, which extends through the housing, to a valve member (8) for controlling application of suction to the collecting chamber (6) and milk suction ducts (2). The pressure in the control chamber (15) can be influenced through a ventilation duct (4) from a feat cup (1) connected to one of the suction ducts (2). When an air entry opening (3) of the duct (4) at the feat cup is closed, the control chamber (15) is evacuated by suction applied through a passage surrounding the coupling rod, and the diaphragm (11) is disposed so as to cause the valve member (8) to open and allow application of suction to the collecting chamber (6). The element (3) may be replaced by a spring-loaded double valve or an electromagnetic valve. <IMAGE>

Description

SPECIFICATION Vacuum milking equipment The present invention relates to vacuum milking equipment, particularly for sheep milking.

Milk collecting units for sheep milking equipment in principle have the same construction as milk collecting units for the milking of cows. The main differences are that only two teat cups are employed and that the hoses between the teat cups and milk collecting unit do not, during application of the cups, kink under the weight of the cups and close the air supply. Instead, the milk collecting piece must be closed by a valve when the cups are removed and opened by the valve before re-application of the cups. Cone valves, plate valves, skirt-shaped valves and flaps have been used for this purpose. The valves are often arranged so as to automatically close when air unintentionally penetrates into the teat cups if the cups fall off or are removed.

In order to prevent automatic closing of the valves during rinsing of the cups, detents are provided to hold the valve open.

German (Dem. Rep.) patent specification 86 709 describes an automatically controlled milk collecting unit which is provided for a cup removal device, where the milking hoses cannot kink when the cups hang down. In this arrangement, the milk collecting unit has two control diaphragms which under time control release a first pair and then a second pair of teat cups in order that air cannot flow in through the last-mentioned milking teat cups and cause the applied cups to drop off and air to get into the hose. This control requires a pneumatic or electronic control part and a pneumatic switching valve. The time difference between release of the first pair and the second pair of cups is fixed and the milker must have applied the first pair of cups and guided the other pair to the teats when the valve has completely opened the milk collecting unit, as otherwise the cups will drop off.

In sheep milking equipment, the openings at the teat cup are held closed with the thumbs of both hands in order to prevent the ingress of air after opening of the valve at the milk collecting unit and the openings are freed after guiding towards the teats and application of the cups to the teats. As the low milk yield in case of the sheep means that the milking time is much less than in the case of cows, preparation time is of significance, since this represents a greater proportion of the total milking time. The preparation time must therefore be kept as short as possible in order to increase the throughput of the equipment.

Even though the opening and closing of the valves takes only a short time, this time adds up due to the high throughput of the equipment. Also, holding the teat cup openings closed is physically tiresome for the milker over longer operating periods.

There is accordingly a need for a method of conveniently avoiding air ingress and undesired detachment of teat cups, while enabling increase in throughput performance and facilitating the task of the milker.

According to the present invention there is provided vacuum milking equipment comprising a housing defining a milk collecting chamber connectible to a source of suction, suction duct means connecting a plurality of teat cups to the collecting chamber, valve means for controlling the application of suction through the collecting chamber and cut means, a diaphragm operatively coupled to the valve means and co-operable with the housing to define a control chamber, and control means associated with the teat cups and arranged to so influence pressure in the control chamber as to cause the diaphragm to effect operation of the valve means.

In a preferred embodiment, a milk collecting unit has a control chamber which is closed off outwardly by a diaphragm which is coupled with a valve member which opens and closes a milk suction duct. A push rod of the valve member has a bearing play which provides a passage enabling pressure equalization between the control chamber and milk suction duct when a fresh air supply to the control chamber is blocked. An annular sealing seat, which surrounds the push rod of the valve at a spacing therefrom is arranged in the control chamber to lie opposite the diaphragm. For manual opening and closing of the milk suction duct, the valve member is provided with a handle. One of the teat cups has a projection with nipples and ventilation bore which is connected through a thin connecting pipe with the control chamber.A milker can seize one of the cups in each hand and, until shortly before application of the cup, hold the ventilation bore closed by his or her finger. As a result, the control chamber is evacuated through the annular passage around the push rod of the valve member and the diaphragm bends by means of the external atmospheric air pressure and opens the valve to the milk suction duct. In the end position, the diaphragm lies against the sealing seat. After application of the cup, the ventilation bore is freed so that the control chamber can again stand under atmospheric pressure. However, the space enclosed by the sealing edge remains evacuated through the annular passage so that the diaphragm continues to lie in contact with the seat and hold the valve open.

On removal of the teat cups, the milk collecting unit can be ventilated through manual closing of the valve or the test cups can be drawn off so that the inflowing air closes the valve. Such a system allows the teat cups to be applied in a convenient manner and no time loss for the opening and closing of the valve occurs.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a partly sectional schematic view of part of milking equipment according to a first embodiment of the invention; Figure 2 is a partly sectional schematic view of part of milking equipment according to a second embodiment of the invention; and Figure 3 is a partly sectional schematic view of part of milking equipment according to a third embodiment of the invention.

Referring now to the drawings, there is shown in Fig. 1 sheep milking equipment comprising a milk collecting unit 5 the housing of which defines a milk collecting chamber 6 and a stub pipe 7 for connecting the chamber 6 to a source of suction. Communication of the chamber 6 with the source of suction is controlled by a valve member 8.

The chamber 6 is additionally connected by milking hoses 2 to two milking teat cups 1, to which further hoses are connected for application of pulsating suction.

The housing of the unit 5 is also provided with a control chamber 1 5 which is closed by a diaphragm 11. The diaphragm 11 is connected by an operating rod 9 with the valve member 8 and the control chamber 1 5 is communicable with the source of suction by way of an annular passage 14 surrounding the rod 9. The rod 9 is provided with a knob 10 for manual operation of the diaphragm and valve member. Arranged in the control chamber is an annular valve seat 1 2 which is co-operable with the diaphragm 11 and which surrounds the rod 9 at a spacing so as to define therebetween a space 1 6. The control chamber is connected by way of a stub pipe 1 3 and a thin ventilation hose 4 with a manually closable ventilation control element 3 arranged on either or each teat cup 1.

In use, a milker takes one of the teat cups 2 in each hand and inserts these between the rear legs of a sheep onto its teats. Until shortly before reaching the teat, the bore of the control element 3 is held closed by finger.

As a result, communication of the control chamber with the atmosphere is prevented and the control chamber 1 5 is evacuated through the passage 14. The diaphragm 11 is bent by the air pressure, opens the valve member 8 and comes into contact with the seat 1 2. The space 1 6 is consequently separated from the control chamber 1 5 and remains under the influence of the vaccum, even when the control chamber 1 5 is, through freeing of the bore of the control element 3, ventilated by way of the hose 4.

As a result, the diaphragm 11 remains bent and the valve member 8 open. After termination of the milking operation, the bore of the suction stub pipe 7 can be manually separated from the milk collecting chamber 6 by displacing the knob 10 and thus the valve member 8, so that the collecting chamber 6 is ventilated through the ventilation bore and leakages between teat and teat cup and the cups drop off. Equally, the cups can be drawn off under vacuum from the teats so that, as in the case of unintended dropping-off of the cups, the valve member 8 closes and blocks the air access into the milking hose.

Another form of control element for contra ling ventilation of the control chamber 1 5 is shown in Fig. 2. In this case, the control element 1 7 consists of a double valve 1 8 and a compression spring 19. When the double valve 1 8 is pressed by manual pressure against a housing of the control element, this blocks the air access and places the hose 4 in communication with a pulsation suction stub pipe 21 by way of a pulsation suction chamber 20. As a result, the control chamber 1 5 is additionally evacuated by the pulsating vacuum and closing of the valve member 8 is accelerated.

Fig. 3 shows a further embodiment in which the control element 3 is replaced by a key switch 22, which is connected through electrical lines 23 with a small electromagnetic valve 24. On actuation of the switch 22, the valve 24 briefly interrupts an air supply to the control chamber 1 5 so that the chamber is evacuated.

The current supply can take place through dry batteries 25, as the current consumption is very small.

Claims (10)

1. Vacuum milking equipment comprising a housing defining a milk collecting chamber connectible to a source of suction, suction duct means connecting a plurality of teat cups to the collecting chamber, valve means for controlling the application of suction through the collecting chamber and duct means, a diaphragm operatively coupled to the valve means and co-operable with the housing to define a control chamber, and control means associated with the teat cups and arranged to so influence pressure in the control chamber as the cause the diaphragm to effect operation of the valve means.

2. Equipment as claimed in claim 1, the control means comprising a manually closable ventilation duct communicating with the control chamber.

3. Equipment as claimed in either claim 1 or claim 2, wherein the control chamber is connectible to the source of suction by way of passage means surrounding coupling means coupling the diaphragm to a movable valve member of the valve means.

4. Equipment as claimed in any one of claims 1 to 3, wherein the housing is provided in the control chamber with a valve seat respective to and engageable by the diaphragm, the diaphragm and the seat when engaged by the diaphragm co-operating to define a suction space in which underpressure can be induced by the suction source to maintain the diaphragm in engagement with the seat.

5. Equipment as claimed in any one of the preceding claims, the control means comprising a spring-loaded double valve operable to place the control chamber in communication with a pulsation suction chamber of one of the cups.

6. Equipment as claimed in claim 1, the control chamber being connectible to the source of suction and the control means comprising an electromagnetic valve controlling connection of the control chamber to the source and switch means to control operation of the electromagnetic valve.

7. Equipment as claimed in any one of the preceding claims, comprising two such teat cups both adapted for use in milking sheep.

8. Vacuum milking equipment substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

9. Vacuum milking equipment substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.

10. Vacuum milking equipment substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.