Relief-phase pressure control device, teat-cup sleeve and modular teat-cup sleeve system with pressure control in the relief phase

Abstract

According to the invention, a controllable fluid connection is provided in, or in connection with, a teat-cup sleeve (280), for example in the form of a teat-cup connection device (200) of the teat-cup sleeve, as a result of which air / gas is temporarily introduced from the pulsation region (281) into the negative pressure region (220) during the relief phase. As a result, a mechanically robust, efficient and easy-to-clean structure can be provided.

Description

[0001] Relief phase pressure control device, teat cup sleeve and modular teat cup sleeve system with pressure control in the relief phase

[0002] The present invention relates generally to the field of milking technology and in particular to the area of ​​the actual milking process, wherein milk is extracted from a teat via a teat cup by means of a milking system.

[0003] When milking dairy animals, an automated or at least semi-automated milking system is predominantly used. This system generally consists of a vacuum pump that generates the operating vacuum, a milk line that discharges milk from one or more milking stations, and usually several teat cups. The teat cups typically have a number of teats corresponding to the animal species, which are individually applied to each teat of the animal and adhere to it by the operating vacuum created by the vacuum pump.

[0004] Depending on the milking strategy used, milk extraction is carried out with or without stimulation of the animal in such a way that a pulsating drainage of the milk from the teat occurs. This means that the teat cup is equipped with an elastic teat holder, also known as a teat cup liner, which is inserted into a teat cup sleeve and is mechanically stabilized by this and connected to the necessary connections for draining the milked milk. The elastic teat holder, with its outer wall in conjunction with the inner wall of the teat cup sleeve, defines a pulsation chamber or pressure change chamber which is alternately subjected to pressure and negative pressure. So that during operation, if there is negative pressure in the milk draining line and thus in the interior of the teat holder, the teat holder folds in when the pulsation chamber is subjected to pressure, for example atmospheric pressure.This phase is also referred to herein as the relief phase. During this relief phase, the elastic teat socket is pressed much more intensively against the teat, usually closing the teat canal and thus interrupting the milk flow from the teat. At the same time, this folding of the teat socket has a massaging effect on the teat. If, on the other hand, the pulsation chamber is subjected to negative pressure, the elastic teat socket unfolds due to its intrinsic elasticity and the lack of, or very slight, pressure difference between the pulsation chamber and the interior of the teat socket surrounding the teat below the teat. This relieves the lateral pressure on the teat canal. This essentially allows unhindered milk flow due to the negative operating pressure in the interior of the teat socket in the area below the teat.This phase is also referred to as the suckling phase. The frequency and duration of these phases can usually be adjusted based on animal-specific characteristics. Typically, the frequency of a complete cycle, i.e., suckling phase plus relief phase, is 40 to 70 cycles per minute for larger dairy animals and up to 120 or more cycles per minute for smaller dairy animals, such as sheep and goats, with a "cycle ratio" of suckling phase to relief phase of approximately 70% to 30% to approximately 40% to 60%.

[0005] Although this milking technique has proven successful in principle, certain conditions must still be taken into account. For example, at the beginning of the relief phase, its massaging effect on the teat interrupts the milk flow, causing the milk already present in the milk tube to form a kind of milk plug, which must now be drained away via the milk line. However, as this milk plug is removed, the negative pressure above the milk plug, i.e., between the teat and the plug, can increase (i.e., the absolute pressure decreases) due to the milk plug initially moving away and the resulting increase in volume of the empty space between the milk plug and the underside of the teat. This reduces the pressure difference between the suction operating negative pressure in the milk line and the increasing negative pressure between the underside of the teat and the milk plug, making it more difficult for the milk to flow away.

[0006] Furthermore, the increase in negative pressure, i.e. the decreasing absolute pressure, is detrimental to the teat during the actual relief phase because, on the one hand, it experiences a massaging effect, but on the other hand, it is subjected to greater strain due to the increased negative pressure. When switching to the sucking phase, i.e. when the folding of the teat receptacle is eliminated by creating a negative pressure in the pulsation chamber, the previously produced milk plug can under certain circumstances even be accelerated back towards the teat, thus leading to an undesirable, extremely turbulent flow or even wetting of the teat. This means that the ability of the milked milk to drain away is reduced due to the reduced pressure difference after the milk plug has been created, as described above, and, furthermore, very turbulent flow conditions can occur due to the pulsating milking.Under these dynamic conditions, the milk from the different udder quarters mixes. If the milk plug accelerates toward the teat and wets the teat, bacteria can then "shoot" into an otherwise uninfected udder quarter if one udder quarter is infected.

[0007] Therefore, to ensure satisfactory milk removal, the operating vacuum is often increased accordingly, i.e., the absolute pressure is further reduced, creating a greater pressure difference between the atmosphere and the (negative) pressure in the milk line system to ensure sufficient milk removal in all cases. However, the numerically greater negative pressure may have adverse effects on the teat due to the increased load and may also contribute to increased turbulence, although the desired level of milk removal can generally be achieved.

[0008] In addition, attempts are made to introduce air into the milk line at suitable positions in order to counteract the reduction in the pressure difference during the removal of a milk plug. For this reason, for example, air inlet openings are provided at suitable positions to allow a continuous supply of outside air in order to reduce the occurrence of a greater negative pressure under the teat during the removal of the milk. However, this measure represents a compromise between, on the one hand, a generally increased power demanded of the vacuum pump, which must compensate for the introduction of additional air in order to maintain a desired average operating negative pressure, and, on the other hand, the aim of keeping the pressure difference between the pressure under the teat and the rest of the milk line as low as possible, particularly during the relief phase, which counteracts the removal of the milk plug.In other systems, a periodic, i.e., controlled, air intake is carried out so that air is specifically admitted during the phase of the milk plug's removal. This prevents an increase in the numerical magnitude of the negative pressure, i.e., a decrease in the absolute pressure, under the teat, or even causes a slight increase in pressure. The resulting pressure difference between the end of the milk plug facing the teat and the milk line beneath the teat promotes efficient removal of the milk and also essentially prevents the milk plug from being accelerated back toward the teat at the start of the next sucking phase.Due to the fact that the air is only introduced during a specific phase, it is possible to introduce a larger amount of air within a short time interval, whereas, on average, no more or, in some cases, even less air is introduced into the entire milk line system compared to continuous air intake, so that the additional power required by the vacuum pump remains minimal. For this purpose, so-called air intake valves are provided, which, while in principle performing the desired function, have a complex design.

[0009] A further problem associated with milk flow and the introduction of additional air into the milk is the fact that the quality of the milk can generally be adversely affected when it comes into contact with air. Without wishing to limit the present application to any one theory in this regard, it is nevertheless assumed that, in particular, the contact of air with more or less turbulently flowing milk or even "frothy" milk in the milk line, as can be caused, for example, by turbulent flow conditions, leads to an interaction with the free fatty acids in the milk, causing them to be oxidized to a greater extent.It is assumed that this interaction of air with the free fatty acids or other components of the milk, facilitated by the large surface area created by turbulently flowing or "frothy" milk, leads to at least a significant impairment of the milk's flavor, so that, for example, certain dairy products suffer significant quality losses. Another important factor for milk quality is the mechanical "damage" of the milk, particularly during the transfer of the milk from the teat into a milk container, as well as subsequent temporary storage and transport of the milk to the dairy.It is believed that the mechanical interaction of milk components, such as fat droplets, with the components involved in milk drainage leads to the premature release of enzymes, which then leads to a change in the properties of the milk that is not desired at this stage of milk production.

[0010] In addition, when using air inlet valves, which can have a more or less complex design depending on the model, the effort required to clean the teat cluster can be considerable, as only regular cleaning ensures the proper functioning of the periodic air intake during milking. Impairment of the valve function can even lead to an unfavorable pressure curve during milking, thus reducing milk yield and placing additional strain on the animal's teats.

[0011] With reference to Figure 5, the pressure conditions that occur in a conventional teat cup are now described, in which a small amount of air from the ambient atmosphere is permanently supplied to the area below the teat in order to at least partially eliminate the disadvantages of milking described above.

[0012] Figure 5 shows the pressure profile in a pulsation chamber or pressure change chamber, which is formed in a teat cup by mounting an elastic teat holder in a teat cup sleeve, as mentioned above, and the space between the inner wall of the teat cup sleeve and the outer wall of the elastic teat holder forming a gas-tight space. A corresponding pressure source, also referred to as a pulsator, is fluidly connected to this pulsation chamber via a pulsation line and a suitably designed connection.

[0013] Curve A indicates the pressure curve in the pulsation chamber or a connected area. For this purpose, the vertical axis is labeled in accordance with industry practice so that a decrease in absolute pressure is plotted as an increase in the numerical value of the negative pressure or vacuum in kilopascals (kPa). This means that the value zero for the pressure curve indicates the ambient atmospheric pressure, and increasing values ​​indicate an increasing vacuum or an increasing negative pressure relative to the ambient atmospheric pressure. A large numerical value for the pressure curve indicates a low absolute pressure and thus a "high" negative pressure.

[0014] The following explanations describe the pressure conditions during operation, i.e. there is generally a constant negative pressure in the milk discharge line and thus inside the elastic teat holder, generated by a vacuum pump, which, however, varies particularly in the teat area, as already qualitatively described above. In curve A, a temporal phase is designated S, which is also referred to as the suction phase, in which negative pressure or vacuum is generated in the pulsation chamber due to the connection with the pulsator. This means that within approximately one tenth of a second, air is sucked out of the pulsation chamber, and the operating negative pressure generated by a corresponding vacuum pump is established. In the example shown, this is approximately 42 kPa.The negative pressure required for the pulsator and the negative pressure in the milk line are usually generated by one and the same vacuum pump, but can also be generated by individual vacuum pumps that are decoupled from each other.

[0015] After approximately 0.6 seconds, the pulsation chamber is filled with atmospheric pressure, initiating the so-called relief phase E. The pressure in the pulsation chamber corresponds to the ambient atmospheric pressure, resulting in a large pressure difference with the interior of the teat cup, which causes the teat cup to collapse and interrupts the milk flow from the teat. After approximately another 0.4 seconds, air is then again supplied to the pulsation chamber, ultimately restoring the operating negative pressure.

[0016] Curve B describes the pressure curve directly beneath the teat. As shown, a certain negative pressure develops during the sucking phase, which is below the actual operating negative pressure for much of the sucking phase. During this sucking phase S, there is only a very small pressure difference between the interior of the elastic teat cup, i.e., the area beneath the teat, and the pulsation chamber, so that the elastic teat cup essentially maintains its normal, unstressed shape, allowing milk to flow from the teat relatively unhindered.

[0017] As previously mentioned, this conventional milking process involves a continuous supply of outside air, which, depending on the size of the outside air supply line, typically results in a certain pressure loss compared to the negative pressure value in the pulsation chamber. Therefore, a correspondingly high negative pressure value must generally be provided to achieve the desired milking performance, i.e., milk flow, during the suction phase S. As previously explained, the vacuum pump must provide the appropriate additional pumping power to maintain the required operating negative pressure while continuously supplying air.

[0018] When the relief phase begins, the continuously supplied ambient air reduces the negative pressure or increases the absolute pressure under the teat, allowing the corresponding milk plug to drain efficiently. However, curve B shows that this desired drop in negative pressure only lasts for a relatively short time, and the pressure under the teat then rises again to approximately 35 kPa. When the pressure in the pulsation chamber switches to initiate the next suction phase, a certain increase in negative pressure can be seen, caused by the elastic teat receptacle unfolding. Subsequently, an average pressure of approximately 35 to 36 kPa is restored under the teat.

[0019] The pressure conditions under the teat according to curve B depend, among other things, on the current milk flow and, in particular, on the size and diameter of the supply line for the continuous air supply. It is clear, however, that a relatively high value for the operating negative pressure of approximately 42 kPa is required in order to be able to drain away the amount of milk produced, while the desired reduction in the negative pressure value in the relief phase E is very slight and only lasts for a short time. This means that a structurally relatively simple approach to improving the pressure conditions during the milking process only leads to the desired pressure curve to a limited extent, for example in the relief phase, but requires a relatively high value for the operating negative pressure, whereby the reduction in the negative pressure only occurs when there is sufficient milk flow and, without milk in the line, the "full" operating negative pressure acts on the teat tissue.

[0020] On the other hand, the pressure curve can be improved by providing the previously mentioned controlled valves, which specifically allow air to be admitted from the ambient atmosphere only during the relief phase, although this requires a higher design effort both for the teat cup itself and for the valve, and the previously mentioned additional measures for cleaning the corresponding valves must be provided.

[0021] In view of the situation described above, it is therefore an object of the present invention to provide means which can generally contribute to a desired pressure curve during the milking process and thus to an increase in the efficiency of milk removal and to mitigate at least one of the aforementioned limitations.

[0022] According to one aspect of the present invention, the aforementioned object is achieved by a relief phase pressure control device designed for connection to a teat cup sleeve part accommodating an elastic teat receptacle. The relief phase pressure control device has a pulsation region with a first connection designed for connecting a pulsation line. Furthermore, the relief phase pressure control device has a negative pressure region with a second connection designed for connection to a milk discharge line.Furthermore, a controllable fluid connection is provided between the pulsation region and the negative pressure region, wherein the fluid connection is controllable in such a way that in a first operating state with a first pressure in the pulsation region the fluid connection is at least temporarily open, and that in a second operating state with a second pressure in the pulsation region the fluid connection is closed, wherein the first pressure is higher than the second pressure. A pulsation region in the sense of the invention is to be understood as a spatial region in which high pressure and low pressure alternate during the milking process, i.e. when there is a permanent negative pressure in the milk line and thus inside the elastic teat receptacle, in order to operate the typical milking process with a suction phase and a relief phase as described at the beginning. This means that the pulsation region is a spatial region which is provided with a pulsation chamber orPressure change chamber, which is formed in a teat cup sleeve after assembly of the elastic teat holder, is connected and is alternately subjected to the high pressure and the low pressure in the pulsation chamber or pressure change chamber via the first connection.

[0023] A "high" or higher pressure is understood to mean a pressure that causes the elastic teat cup to fold during the milking process, i.e., when a negative pressure prevails permanently inside the teat cup and in the milk discharge line, and which is generally close to atmospheric pressure. In certain applications, the first, high pressure can also be a pressure that is higher than or even lower than atmospheric pressure if the relevant pressure source or pulsator is operated independently of the ambient atmosphere. The second, "lower" pressure is a pressure, often referred to as a vacuum, which generally corresponds to the operating negative pressure generated by a corresponding vacuum pump during the milking process.The term second, "lower" pressure is intended in the context of this application to describe a negative pressure in relation to the atmospheric ambient pressure, which has, among other things, the consequence that in the sucking phase the inherent elasticity of the elastic teat receptacle leads to the elastic teat receptacle assuming its original, i.e. unstressed, shape and thus enabling an almost unhindered discharge of milk from the teat.

[0024] The "negative pressure area" generally refers to a spatial area that, during the milking process, is connected to the interior of the elastic teat holder and also to all other volumes connected to the milk discharge line, so that a certain negative pressure is present there at least permanently, which, however, can vary depending on the location and phase during the milking process, as explained above with reference to Figure 5, for example. In general, the relief phase pressure control device represents part of the pressure control in the teat cup or even represents part of a teat cup sleeve itself if the relief phase pressure control device is designed as a teat cup connection device and then typically represents the "lower" area of ​​the teat cup, if the part of the teat cup sleeve into which the teat is inserted during the milking process is referred to as the "top".

[0025] In the relief phase pressure control device, the pulsation region and the vacuum region are thus structurally arranged close to one another, allowing the corresponding controllable fluid connection to be implemented in a very compact manner. This means that the controllable fluid connection between the pulsation region and the vacuum region enables the targeted introduction of air / gas during the first operating phase, which corresponds to the relief phase. The controlled opening and closing of the fluid connection can be achieved by any suitable means, such as by influencing an elastic component of the fluid connection, by suitable valve devices, and the like.As explained in more detail below, the controllability of the fluid connection can be achieved using structurally simple means, so that the effort required to control the air / gas introduction can remain relatively low compared to conventional teat cup sleeves. The relief phase pressure control device, if designed as an assembly independent of the teat cup sleeve part, can be arranged at any location and connected via a suitable fluid line to the teat cup sleeve or a section of the milk discharge line and the pulsator line located near the teat cup sleeve.

[0026] By deliberately opening the fluid connection during the first operating state, i.e. at least during part of the relief phase, a defined amount of air or gas, depending on the operating gas used for the pulsation operation, can be introduced into the negative pressure zone, so that advantageous pressure conditions can be set there for draining the milked milk after the milk flow from the teat has been interrupted. In particular, the duration of the introduction of air or gas into the negative pressure zone can be better controlled compared to a continuous air introduction, so that a more effective reduction in the negative pressure, i.e. an increase in the absolute pressure in the negative pressure zone, is possible for draining milk in the critical relief phase, without, however, increasing the total amount of gas or air introduced into the milk, or this can even be reduced.Accordingly, more favorable flow conditions can be created during milk removal, thus reducing the likelihood of turbulent flow and all its adverse effects on the milk. By specifically increasing the absolute pressure or reducing the negative pressure during the relief phase, the maximum operating negative pressure can typically also be reduced, thus reducing the damaging effect on the teat and thus achieving a more animal-friendly milking process.

[0027] In an advantageous embodiment, the opening of the controllable fluid connection can be controlled by a positive pressure difference between the pulsation zone and the negative pressure zone. A positive pressure difference is understood to mean that the absolute pressure in the pulsation zone is higher than the absolute pressure in the negative pressure zone. Since typical milking systems alternate between high and low pressure in the pulsation zone, this type of control can automatically ensure that the fluid connection opens when the high pressure builds up in the pulsation zone, without the need for additional control measures.For this purpose, suitable means can be provided, for example in the form of a check valve, which, for example, experiences a restoring force due to one or more influences, such as spring force, elastic deformation, gravity, electromagnetic force, magnetic force, and the like, which is initially overcome by the pressure difference and then leads to a closing of the fluid connection when the positive pressure difference disappears.

[0028] In an advantageous embodiment, the positive pressure difference and / or the reaction of the controllable fluid line to the positive pressure difference are adjustable. This measure makes it possible to vary the point at which the fluid connection opens in order to take into account the different conditions of the respective milking process. The term "adjustable" is to be understood, on the one hand, to mean that the size of the positive pressure difference can be adjusted directly in real time by changing a manipulated variable. On the other hand, it also describes the possibility of changing the response threshold for opening the fluid connection by replacing one or more components of the fluid connection.If an otherwise stationary component, such as a ball, a spring, an elastic material part, or the like, essentially determines the response threshold and thus the magnitude of the positive pressure difference required to open the fluid connection, then replacing such a component can adjust and thus change the magnitude of the positive pressure difference during a suitable phase of the milking process. This means that the response threshold of the controllable fluid line, which can also be understood as a reaction to the positive pressure difference, can also be adjusted by suitable measures.

[0029] In advantageous embodiments, the controllable fluid connection comprises a valve device. Since valve devices capable of fulfilling the previously described function are widely available, this results in a broad range of possible practical implementations, thus covering the requirements of many different operating situations.

[0030] In further advantageous embodiments, the valve device is controlled by the positive pressure differential. This makes it possible to establish the required function of the controllable fluid connection without requiring additional control variables for actuating the valve device. This allows for a very compact, simple, and efficient design.

[0031] In an advantageous embodiment, a region of the controllable fluid connection is designed such that the positive pressure difference causes elastic material deformation to open the controllable fluid connection in said region. This means that by appropriate elastic deformation of a portion of the fluid connection, the fluid connection can be opened and closed based on the pressure difference without the provision of additional controllable components. For example, a membrane can be elastically suspended in spatial relation to a corresponding sealing surface such that elastic deformation of the suspension and / or the membrane itself caused by the pressure difference leads to opening of the fluid connection, while when the positive pressure difference disappears, the inherent elasticity leads to closing of the fluid connection.In other variants, a deformable hose element can be released from the opening when a positive pressure differential is present, thus opening the fluid connection. Many technical possibilities are available in which a pressure-induced change in shape allows flow through the fluid connection, while when a certain pressure differential is removed, the inherent elasticity then leads to closure and interruption of flow.

[0032] In an advantageous embodiment, the controllable fluid connection has a lip valve. A lip valve is typically a valve device in which at least one elastically deformable component has a sealing surface which, in the absence of a pressure difference or a pressure difference that is below a response threshold, rests against a complementary sealing surface and thus leads to the closing of the lip valve. When a corresponding pressure difference occurs, the at least one elastic component with a sealing surface is detached from the complementary sealing surface, opening the fluid connection and thus causing flow. According to the invention, the term lip valve is therefore to be understood as a valve device in which at least one elastic component carrying a sealing surface contributes to the opening of the valve when pressure is applied.Two or more corresponding elastic components with a sealing surface can also be provided, which, when the pressure difference is below the response threshold, tightly engage corresponding complementary sealing surfaces. One or more of the complementary sealing surfaces can also be elastically deformable components or lips. By selecting different materials and / or material thicknesses and / or dimensions, the response threshold and / or flow rate of such a lip valve can be efficiently adjusted.

[0033] Advantageously, the relief phase pressure control device is designed as a teat cup connection device and thus enables a compact design of the teat cup with integrated control of the relief phase pressure.

[0034] According to a further aspect of the present invention, the object mentioned at the outset is achieved by a teat cup sleeve which is designed to receive an elastic teat holder. For this purpose, the teat cup sleeve has a pulsation region with a first connection which is designed to connect a pulsation line, and a negative pressure region with a second connection which is designed to connect a milk discharge line. Furthermore, a controllable fluid connection is provided in the teat cup sleeve between the pulsation region and the negative pressure region, wherein the controllable fluid connection is controllable such that in a first operating state with a first pressure in the pulsation region the fluid connection is at least temporarily open, and that in a second operating state with a second pressure in the pulsation region the fluid connection is closed, wherein the first pressure is higher than the second pressure.

[0035] According to this aspect of the present invention, the provision of the controllable fluid line, which otherwise has the same functional features as in the previous aspect, is not limited to a specific spatial region in the teat cup sleeve, so that the fluid connection, the pulsation region, and the negative pressure region can be arranged according to certain structural or other criteria, thus providing a high degree of design freedom. This means that teat cup sleeves are often used in conjunction with certain automated or semi-automated milking systems and therefore require certain design features. For example, certain teat cup sleeves are available as indivisible units, which can result in certain criteria for the arrangement of components, such as bores and the like.It may also be necessary to provide the first and second connections further apart from each other, so that the pulsation area and the negative pressure area may also have a greater spatial distance from each other, which may require a longer extension of the controllable fluid connection.

[0036] In an advantageous embodiment, the teat cup sleeve has a teat cup connection device and a teat cup sleeve part provided for receiving the elastic teat receptacle, and the first connection, the second connection, and the controllable fluid connection are provided in the teat cup connection device. In this embodiment, essential components of the teat cup sleeve, i.e., the first connection, the second connection, and the controllable fluid connection, are thus provided in a lower region of the teat cup sleeve, so that a spatially very compact design is possible, as already explained above in connection with the relief phase pressure control device when it is designed as part of the teat cup sleeve, for example as a teat cup connection device.

[0037] In a further embodiment, the teat cup sleeve comprises a teat cup connection device and a teat cup sleeve part serving to receive the elastic teat cup, and the first connection and / or the second connection and / or the controllable fluid connection are provided in the teat cup sleeve part. A teat cup sleeve constructed in this manner allows for "equalization" of the corresponding components and enables suitable adaptation to existing milking systems.

[0038] In an advantageous embodiment, the teat cup connection device and the teat cup sleeve part are connected to each other by a mechanically reversible coupling. In this embodiment, the teat cup sleeve comprises at least two parts that can be attached to and detached from each other, with the attachment and detachment processes being referred to as reversible processes. This means that the attachment and detachment can be performed repeatedly without permanently altering or damaging the corresponding components.

[0039] Further advantageous embodiments of the teat cup sleeve implement features that have already been explained in connection with the relief phase pressure control device. Therefore, explicit reference is made here to these previously explained features.

[0040] According to a further aspect of the present invention, the object mentioned above is achieved by a modular teat cup sleeve system. The system comprises a plurality of relief phase pressure control devices, which are structurally designed as previously explained in connection with the relief phase pressure control device. Furthermore, the teat cup sleeve system comprises a teat cup sleeve part, which can be reversibly connected to one of the plurality of relief phase pressure control devices via a fluid line. This means that at least a plurality of relief phase pressure control devices are provided in this modular teat cup sleeve system, which can be connected to the teat cup sleeve part and reversibly detached therefrom.In particular, embodiments provide for each of the multiple relief phase pressure control devices to be mechanically coupled directly to the teat cup sleeve part, thereby creating a single, complete teat cup sleeve. This results in a high degree of adaptability of a teat cup sleeve to the requirements of a specific milking system or even adaptability to different milking conditions. For example, relief phase pressure control devices, such as foot parts tailored to different flow rates, can be quickly and easily coupled in order to accommodate the milking behavior of a specific animal or group of animals, different teat cup sleeves (i.e., their different lengths and / or diameters), or different animal species (i.e., the species-specific teat lengths and / or teat diameters), etc.

[0041] In an advantageous embodiment, the plurality of relief phase pressure control devices differ by at least one parameter influencing the flow through the controllable fluid connection in the first operating state. This means that one or more parameters can be determined that exert a corresponding influence on the operation of the fluid connection and thus also on the overall milking behavior. One or more of these parameters can then be examined for their suitability for a specific animal or group of animals, and suitable values ​​can be determined. The corresponding adjustment can then be accomplished simply by replacing the corresponding relief phase pressure control device, so that a desired value or an approximately desired value for one or more of these parameters determines the operation of the fluid connection.

[0042] In an advantageous embodiment, the at least one parameter influencing the flow through the controllable fluid connection comprises an effective cross-sectional area of ​​the controllable fluid connection in the first operating state and / or a response threshold for opening the fluid connection. This means that in this advantageous embodiment, the effective cross-sectional area of ​​the controllable fluid connection in the open state and / or the response threshold for opening represent significant influencing factors and can be suitably adjusted in the teat cup sleeve system by selecting and installing suitable relief phase pressure control devices, for example in the form of foot parts, that correspond to the desired parameter values.The effective cross-sectional area of ​​the fluid connection can be easily adjusted, for example, by providing a precisely defined constriction, or by providing a line with a constant cross-sectional area, for example, with a constant diameter, and applying correspondingly different constrictions or cross-sectional areas in different base sections. The response threshold for opening the fluid connection can be achieved, for example, by control signals, such as valve devices with external control, for example, pneumatic control, electromagnetic control, and the like.In other embodiments, it is possible to adjust the response threshold through internal measures, such as the weight and / or shape of a ball or other valve body, the elasticity and / or general material properties and thickness of a part of the fluid connection, the shape and size of elastic areas of valves, for example, the "lips" of lip valves, and the like. Adjusting the response threshold, as well as other properties of the fluid connection, can also be achieved by replacing the entire relief phase pressure control device or just individual components.

[0043] In general, it should be noted that the provision of the controllable fluid connection in relief phase pressure control devices, foot sections, or even in other, possibly non-divisible, teat cup sleeves results in a significantly larger application area in which efficient milking is achieved, such as the range of manageable milk flow rates, etc., compared to conventional teat cup sleeves with continuous air inlet. The design effort and, in particular, the effort required for daily handling of the relief phase pressure control devices according to the invention or teat cup sleeves or foot sections with integrated relief phase pressure control device are significantly reduced compared to known air inlet valves. However, this significantly improves operational reliability and economic efficiency compared to conventional solutions.

[0044] With reference to Figures 1A, 1B, 2-4, and with repeated reference to Figure 5, further illustrative embodiments of the present invention will now be described in more detail. In the figures:

[0045] Figure 1A is a schematic plan view of a relief phase pressure control device designed as a teat cup connection device, according to illustrative embodiments,

[0046] Figure 1 B shows a cross-section along line AA in Figure 1 A,

[0047] Figure 2 is a schematic sectional view of a teat cup based on a teat cup sleeve provided as an indivisible component or as a component with a foot part and teat cup sleeve part or as a component of a modular teat cup sleeve system,

[0048] Figure 3 shows a graphical representation of the pressure curves according to illustrative embodiments,

[0049] Figure 4 is a descriptive representation of pressure curves according to illustrative embodiments, wherein one or more parameter values ​​influencing the flow in the fluid connection are changed compared to the representation in Figure 3, and

[0050] Figure 5 is a schematic representation of the pressure curve in a conventional teat cup with continuous air supply.

[0051] Figure 1A shows a schematic top view of a relief phase pressure control device 100, which is designed here as the base part of a teat cup sleeve, also referred to herein as a teat cup connection device, which forms part of a teat cup sleeve. The relief phase pressure control device 100 can be provided as an assembly independent of a teat cup sleeve and can be connected to the teat cup sleeve or a line connected thereto via a fluid line (not shown).

[0052] The relief phase pressure control device 100, for example in the form of a teat cup connection device, has a pulsation region 110 which, as already explained at the beginning, is alternately subjected to a first, high pressure and a second, low pressure during milking. In particular, at low pressure, the operating vacuum or negative operating pressure is essentially present, which, depending on the design of the respective milking system, is approximately 40 to 48 kPa in typical prior art applications. At high pressure, the ambient atmospheric pressure typically prevails in the pulsation region 110 in many applications, but can also assume a different high value if a corresponding gas source with a suitable pressure source is provided to supply the pulsation region 110.The pulsation area is connected via a connection 111 via a suitable pulsation line 112 to a pressure source (not shown), which alternately provides the high and low pressure.

[0053] Furthermore, the relief phase pressure control device 100 has a negative pressure region 120 which is connected to a milk discharge line via a connection 121 and via a fluid line 122 or to a corresponding milk discharge system via the milk discharge line itself if the relief phase pressure control device 100 is provided, for example, in the form of a teat cup connection device, and is thus permanently subjected to negative pressure during operation.

[0054] It should be noted that the corresponding pressure conditions in the pulsation region 110 and the negative pressure region 120 only prevail when the relief phase pressure control device 100 is connected to a suitable teat cup sleeve part, which is assembled to form a teat cup with an elastic teat receptacle mounted therein. Alternatively, if the relief phase pressure control device 100 is provided in the form of the teat cup connection device, the pressure conditions arise after assembly and during operation of a teat cup, as described in more detail below with reference to Figure 2.

[0055] Furthermore, a controllable fluid connection 130 is provided in the relief phase pressure control device 100, which establishes a connection between the pulsation region 110 and the negative pressure region 120 during a first operating state and essentially interrupts the corresponding connection during a second operating state. The controllable fluid connection 130 is thus constructed such that, in the first operating state, which corresponds to at least part of a relief phase, it at least temporarily establishes a flow connection between the pulsation region 110 and the negative pressure region 120. In the second operating state, in which a low pressure prevails in the pulsation region 110, which corresponds to the suction phase, however, a flow connection between the pulsation region 110 and the negative pressure region 120 is inhibited or essentially interrupted.

[0056] The control of the fluid connection 130 in the manner according to the invention is carried out by various technical means, such as by a valve device, by correspondingly deforming a part of the controllable fluid connection 130, and the like. For example, a controlled opening of the fluid connection 130 can occur due to a pressure difference prevailing during operation between the pulsation region 110 and the negative pressure region 120. A pressure difference results from the application of high pressure to the pulsation region 110 to initiate the relief phase, wherein a flow occurs due to the design-related properties of the fluid connection 130. For example, the pressure difference occurring during operation can lead to an elastic deformation of a part of the fluid connection 130, whereby the fluid connection 130 is then opened and enables a flow from the pulsation region 110 into the negative pressure region 120.Suitable means for utilizing a pressure difference to open a flow channel include, for example, a check valve with a corresponding flap or diaphragm, a ball valve actuated by gravity or spring force, and the like. In an advantageous embodiment, the fluid connection 130 has a lip valve 135 having one or more sealing surfaces designed as lips, which are pressed apart when a corresponding pressure is applied on the side of the pulsation region 110. If there is no pressure difference or a pressure difference that is below the response threshold of the lip valve 135, the lip valve 135 closes the corresponding flow channel due to the elastic properties of its lips.In the embodiment shown, the lip valve 135 is inserted into a bore 132 in the relief phase pressure control device 100 and, if appropriate, also has a corresponding channel 133 whose cross-sectional area is adapted according to the desired properties of the fluid connection 130. The bore 132 is further covered by a cap 131, ensuring that the fluid connection 130 is sealed against the ambient atmosphere.

[0057] As previously explained, the bore 132 can, however, also accommodate any other type of controllable valve device to achieve the desired function. The use of the lip valve 135 is particularly advantageous because this component can be manufactured simply and efficiently, for example by injection molding, by 3D printing, for example for individual adaptation, or the like, from a suitable material, such as silicone, and the like, and its properties can be precisely and reproducibly adjusted through design measures, i.e., through appropriate structures in the mold. For example, different material thicknesses, different sizes and surfaces, and the like can be produced, so that the response behavior of the lip valve 135 at different pressure differences and, if necessary, also the size of the flow channel can be adjusted.Furthermore, the effective flow cross-section can also be adjusted based on line 133. In general, valve devices that are controllable depending on the pressure difference have the advantage that external control signals are typically not required. In other embodiments, in which corresponding external control signals are available or can be supplied at reasonable expense, other valve devices can also be used, including, for example, electromagnetic valve devices, pneumatically controlled valve devices, piezoelectric valve devices, electric valve devices, mechanical valve devices, gravity-controlled valve devices, material deformation-controlled valve devices, and the like.

[0058] Furthermore, in the illustrated embodiment, a coupling region 140 is provided, which enables a reversible coupling of the relief phase pressure control device 100, which in this embodiment is designed as a teat cup connection device, to a corresponding teat cup sleeve part. For example, an internal thread is provided in the coupling part 140, which can be correspondingly engaged with a complementary thread of a teat cup sleeve part. Other coupling mechanisms known per se can also be provided, such as snap-in closures, etc.

[0059] Figure 1B shows a section of the relief phase pressure control device 100 along line AA of Figure 1A. Here, it can be seen that the pulsation region 110, which surrounds a portion of the negative pressure region 120 in a ring shape, is connected to a corresponding channel 134 and then, via line 133, to the lip valve 135, which in turn opens into the negative pressure region 120. The cap 131 closes the bore that accommodates the components 133 and 135. Thus, if necessary, the lip valve 135 can be removed with the line 133 by removing the cap 131. This allows for easy replacement, for example, for cleaning, due to wear, to adjust the functional behavior, etc.

[0060] Figure 2 shows a schematic sectional view of a teat cup 290, which in one embodiment has a teat cup sleeve 280 in which an elastic teat receptacle 291, also referred to as a teat rubber, is installed. In embodiments, for example, the teat cup sleeve 280 is provided as a single component in which a pulsation region 210 and a negative pressure region 220 are present. Furthermore, a controllable fluid connection 230 is provided, which, when high pressure is present in the pulsation region 210, opens a flow connection between the region 210 and the negative pressure region 220, as also previously described.

[0061] In other embodiments, the sleeve of the teat cup 290 is constructed from a teat cup sleeve part, also designated by the reference numeral 280, and another part, designated as the teat cup connection device 200. The two parts 280 and 200 are connected to one another by a coupling region 240 such that reversible coupling and uncoupling is possible. For this purpose, for example, the coupling region 240 has a thread in the teat cup connection device 200 and a complementary thread in the teat cup sleeve part 280. However, other coupling mechanisms can also be used, such as snap fasteners and the like. This allows for disassembly for cleaning, replacement due to wear, adjustment of the functional behavior, in terms of length, diameter, etc., without great effort.

[0062] In other embodiments, a relief phase pressure control device is provided as an independent assembly, which is connected to the negative pressure region 220 and the pulsation region 210 via connecting lines (not shown), but otherwise represents an independent assembly without any further mechanical connection to the teat cup 290. The controllable fluid connection 230 is thus provided in the independent assembly, so that the overall volume of the assembly, the dimensions of the assembly and / or the location of the assembly's installation, etc., can be selected very flexibly.

[0063] In an advantageous embodiment, the device 200 is of the same design as the relief phase pressure control device 100 described in connection with Figures 1A and 1B, for example as a teat cup connection device, so that a connection 211, which is connected to the pulsation region 210, and a connection 221, which is connected to the negative pressure region 220, are provided in the teat cup connection device 200. This means that the connection 211, the connection 221 and the controllable fluid connection 230 are accommodated in the base 200. In other embodiments, one or more of the components 211, 221 and 230 are provided in the region of the sleeve part 280. For example, in one embodiment, the connection 211 is not provided in the base 200 but as a connection 282 in the teat cup sleeve part 280. Other designs can also be used to meet the specific requirements of the milking conditions.The fluid connection 230 can be provided entirely or partially in the teat cup sleeve part 280, so that a high degree of design flexibility is achieved, in particular if the size of the foot part 200 makes the integration of all components of the controllable fluid connection 230 difficult.

[0064] In other embodiments, several parts 200, which can also be relief phase pressure control devices as independent assemblies that can be connected to the teat cup sleeve part 280 by suitable lines and thus have a connection to the corresponding areas, are provided for one or more teat cup sleeve parts 280, so that together they form a teat cup sleeve system 280, 200, wherein in particular two or more of the parts 200 have differences to enable adaptation to different milking conditions, milking systems, and the like. For example, the teat cup sleeve feet 200 can differ in at least one parameter that influences the function of the controllable fluid line 230.Such parameters include, for example, the effective cross-section of a flow channel in the open state of the fluid connection 230, so that during operation under prevailing pressure conditions, the overflowing gas quantity can be adjusted by selecting the effective cross-section. Furthermore, the various relief phase pressure control devices, such as the teat cup sleeve feet, can differ in other parameters, such as the response behavior when opening the fluid connection 230, the behavior when closing the fluid connection 230, and the like. For example, the elastic properties of materials used in the fluid connection 230 can be designed differently in the various connection devices or relief phase pressure control devices 200, resulting in different functional behavior.A targeted selection of the previously described components 133 / 135 also allows for individual determination of the functional behavior of the respective relief phase pressure control devices. In this way, the functional behavior of the teat cup 290 can be adjusted to the desired extent by setting parameters that influence the flow behavior or generally the function of the fluid connection 230.

[0065] During operation, the teat cup 290 with the sleeve 280, 200 is attached to the teat of a dairy animal, while negative pressure is created via the connection 221 and a corresponding line (not shown) in the negative pressure region 220, whereby the elastic teat receptacle 291 conforms to the corresponding teat and encloses it in a substantially gas-tight manner. In other embodiments, one of the relief phase pressure control devices, also designated 200 here, is connected to the sleeve 280 in conjunction with a connection device (not shown), so that a functional coupling is achieved via the connecting lines and the controllable fluid connection 230 provided in the independent assembly, regardless of the installation location of the relief phase pressure control device.

[0066] During the actual milking process, which may be preceded by a more or less pronounced stimulation phase, alternating high pressure and low pressure are induced in the pulsation region 210 and thus also in a corresponding pulsation chamber 281 via a corresponding line at connection 211, if the connection is provided on the foot part 200, or at connection 282, if this is provided on the teat cup sleeve part 280. In an operating state with high pressure in the pulsation region 210 and thus also in the pulsation chamber 281, the pressure difference between the pulsation chamber 281 and inside the elastic teat holder 291 leads to a folding of the teat holder 291 below the teat, thereby initiating the relief phase.During this phase, gas or air from the pulsation region 210 and thus from the chamber 281 is simultaneously introduced, at least temporarily, into the negative pressure region 220 via the now opened fluid connection 230, thereby reducing the prevailing negative pressure there, i.e., increasing the absolute pressure to a certain degree. This facilitates the removal of the milk drained from the teat during the sucking phase, as already explained above.

[0067] Figure 3 shows the pressure curve in a teat cup, such as the teat cup 290 with the controllable fluid connection 230 or another teat cup to which the relief phase pressure control device 100 is connected or in which the relief phase pressure control device 100 is integrated, for example in the form of the teat cup connection device. For the sake of simplicity, the following description refers only to the teat cup 290. It should be noted that the description also applies to any teat cup in which, for example, the relief phase pressure control device 100 is installed or connected, for example as a teat cup connection device with a controllable fluid connection.

[0068] Curve A1 describes the regularly changing pressure curve in the pulsation region 210 and thus the pulsation chamber 281, wherein in the phase designated S, i.e. the suction phase, the value of the negative pressure increases to a certain maximum value which corresponds to the operating vacuum. In the present embodiment, a value of approximately 36 kPa is used. This value then drops subsequently in the so-called relief phase E within a certain period of time to the value 0, which in the present embodiment essentially corresponds to the atmospheric ambient pressure. It should be noted that other pressure values ​​can be used if the pulsation chamber 281 is pressurized with gas or air via the connection 211 or 282 from another suitable pressure source which operates independently of the atmospheric ambient pressure.

[0069] Curve B1 shows the pressure curve, which is measured here directly beneath the teat using a suitable measuring probe. As can be seen, a maximum pressure of over 40 kPa is applied to the teat for a short period in the suction phase S and then decreases continuously until the start of the relief phase E. The negative pressure is then significantly reduced by the inflow of gas or air from the pulsation chamber 281, since the fluid connection 230 is open. The inflow of gas or air during this phase therefore reduces the negative pressure, i.e. the absolute pressure increases slightly, so that the milk plug can be drained away more efficiently, as explained in more detail at the beginning. The reduced negative pressure beneath the teat during this relief phase E also leads to less mechanical stress on the teat and thus promotes a more beneficial massaging effect on the teat.The reduction in the negative pressure lasts for a substantial part of the relief phase and when the high negative pressure in the pulsation area 210 is built up again, the negative pressure under the teat also increases again when the elastic teat holder 291 is unfolded, which can then exceed the operating negative pressure that prevails, for example, in the pulsation chamber 281 and thus contributes to an efficient drainage of milk from the teat.

[0070] In contrast to the conventional procedure, which is shown in Figure 5, the periodic air or gas inlet through the controllable fluid connection results in a significantly more favorable pressure curve compared to the prior art. This means that for the same milk flow rate, approximately 1.9 l / minute per teat, with the same effective cross-section of the effective flow channel for introducing air or gas into the negative pressure region, i.e. for the continuous air inlet in the prior art, a line is used which has the same effective cross-section as the controllable fluid connection 230, it can be seen that according to the invention the required milking performance, i.e. the milk flow rate, can be achieved with an operating negative pressure of only approximately 36 kPa compared to approximately 42 kPa. The maximum negative pressure values ​​in the negative pressure region in the present invention are also limited to approximately40 kPa, whereas in the prior art the negative pressure peaks rise to 45 kPa. Furthermore, the length of the section with significantly reduced negative pressure during the relief phase E in the embodiment according to the invention with controllable fluid connection is significantly longer compared to the continuous air inlet according to the prior art. This means that with the same milk flow rate, a lower operating negative pressure can be used according to the invention, so that corresponding energy losses, etc. due to vacuum pumps and the like are lower and, at the same time, the mechanical stress on the teat during milking is significantly reduced. The longer phase with low negative pressure during the relief phase also enables more efficient milk drainage at higher flow rates.Furthermore, the introduction of gas / air during the suction phase is avoided due to the closure of the fluid connection 230, thus avoiding increased contact of air / gas with milk.

[0071] Figure 4 clearly shows pressure conditions for a teat cup, such as teat cup 290 with the controllable fluid connection according to the invention, wherein a parameter value has been changed compared to the arrangement corresponding to the pressure curve in Figure 3. In this example, the effective diameter of the flow channel has been reduced for fluid connection 230. This can be achieved, for example, by installing or connecting a corresponding relief phase pressure control device 100, or by installing a teat cup connection device, wherein fluid connection 230 or 130 has a correspondingly desired effective cross-section. If necessary, other parameter values ​​that influence the flow conditions in the controllable fluid connection, such as the provision of corresponding components 133 / 135, can also be set, as already explained.Furthermore, the measurement according to Figure 4 was carried out at a flow rate of 0.74 l / minute per teat. Here, too, it can be seen that a lower operating negative pressure of approximately 36 kPa is sufficient to achieve efficient behavior at low flow rates, such as those that occur at the end of a milking process. It can be seen that a significant decrease in the negative pressure value is achieved when the controllable fluid connection 230 is opened and, due to the lower flow rate, a return to the greater negative pressure is already brought about in an earlier section of the relief phase E. Corresponding peak values ​​of the negative pressure are 40 kPa or below, so that gentle milking is also achieved in this phase of the milking process. The milking process is also more efficient because, in the suction phase, the negative pressure at the teat and the negative pressure in the milk discharge line orin the milking system are almost the same, so that no significant flow impairments are caused by pressure differences.

[0072] In summary, it can be stated that by providing a controllable fluid connection between the pulsation zone and the negative pressure zone, improved pressure conditions can be created compared to a continuous air inlet, whereby the connection between the pulsation zone and the negative pressure zone enables a simple design. Control can be achieved by any suitable valve device, with valve devices that open in the presence of a positive pressure differential being particularly advantageous in terms of simple design. For example, lip valves are particularly effective as controllable devices in the fluid connection because they are simple and inexpensive to manufacture.Furthermore, the controllable fluid connection according to the invention can be designed to ensure efficient cleaning during the cleaning process of the milking system and to prevent backspray of milk during milking. This achieves reliable function for maintaining the desired pressure conditions during the milking process without causing any hygienic or mechanical problems in the controllable fluid connection.

Claims

Patent claims 1. Relief phase pressure control device which is designed for connection to a teat cup sleeve part accommodating an elastic teat receptacle and has a pulsation region with a first connection which is designed for connecting a pulsation line, a negative pressure region with a second connection which is designed for connection to a milk discharge line, and a controllable fluid connection between the pulsation region and the negative pressure region, wherein the fluid connection is controllable such that in a first operating state with a first pressure in the pulsation region the fluid connection is at least temporarily open, and that in a second operating state with a second pressure in the pulsation region the fluid connection is closed, wherein the first pressure is higher than the second pressure.

2. Relief phase pressure control device according to claim 1, wherein the opening of the controllable fluid connection is controllable by a positive pressure difference between the pulsation region and the negative pressure region.

3. Relief phase pressure control device according to claim 2, wherein a magnitude of the positive pressure difference and / or a response of the controllable fluid connection to the positive pressure difference are adjustable.

4. Relief phase pressure control device according to one of claims 1 to 3, wherein the controllable fluid connection comprises a valve device.

5. Relief phase pressure control device according to claim 2 and 4, wherein the valve device is controlled by the positive pressure difference.

6. Relief phase pressure control device according to one of claims 2 to 5, wherein a region of the controllable fluid connection is designed such that the positive pressure difference for opening the controllable fluid connection in the region causes an elastic material deformation.

7. Relief phase pressure control device according to one of claims 1 to 6, wherein the controllable fluid connection comprises a lip valve.

8. Relief phase pressure control device according to one of the preceding claims, which is designed as a teat cup connection device for mechanical coupling to the teat cup sleeve part.

9. A teat cup sleeve designed to receive an elastic teat receptacle, having a pulsation region with a first connection designed to connect a pulsation line, a negative pressure region with a second connection designed to connect a milk discharge line, and a controllable fluid connection between the pulsation region and the negative pressure region, wherein the controllable fluid connection is controllable such that in a first operating state with a first pressure in the pulsation region the fluid connection is at least temporarily open, and that in a second operating state with a second pressure in the pulsation region the fluid connection is closed, wherein the first pressure is higher than the second pressure.

10. A teat cup sleeve according to claim 9, wherein the teat cup sleeve comprises a teat cup connection device and a teat cup sleeve part for receiving the elastic teat receptacle and the first connection, the second connection and the controllable fluid connection are provided in the teat cup connection device.

11. A teat cup sleeve according to claim 9, wherein the teat cup sleeve comprises a teat cup connection device and a teat cup sleeve part and the first connection and / or the second connection and / or the controllable fluid connection are provided in the teat cup sleeve part.

12. Teat cup sleeve according to claim 10 or 11, wherein the teat cup connection device and the teat cup sleeve part are connected to one another by a mechanically reversible coupling.

13. A teat cup sleeve according to claim 9, wherein the opening of the controllable fluid connection is controllable by a positive pressure difference between the pulsation region and the negative pressure region.

14. A teat cup sleeve according to claim 13, wherein a magnitude of the positive pressure difference is adjustable.

15. A teat cup sleeve according to any one of claims 9 to 14, wherein the controllable fluid connection comprises a valve device.

16. A teat cup sleeve according to claim 13 and 15, wherein the valve device is controlled by the positive pressure difference.

17. A teat cup sleeve according to any one of claims 13 to 16, wherein a region of the controllable fluid connection is designed such that the positive pressure difference for opening the fluid connection causes an elastic material deformation in the region.

18. A teat cup sleeve according to any one of claims 9 to 17, wherein the controllable fluid connection comprises a lip valve.

19. Modular teat cup sleeve system, with several relief phase pressure control devices each according to one of the Claims 1 to 8, and a teat cup sleeve part which can be reversibly connected to one of the plurality of relief phase pressure control devices by a fluid line.

20. Modular teat cup sleeve system according to claim 19, wherein the plurality of relief phase pressure control devices differ by at least one parameter influencing the flow through the controllable fluid connection in the first operating state.

21. Modular teat cup sleeve system according to claim 20, wherein the at least one parameter influencing the flow through the controllable fluid connection comprises an effective cross-sectional area of ​​the controllable fluid connection in the first operating state and / or a response threshold for opening the fluid connection.

22. Modular teat cup sleeve system according to one of claims 19 to 21, wherein the plurality of relief phase pressure control devices are each designed as teat cup connection devices and are each connectable to the teat cup sleeve part by a mechanically reversible coupling.

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