WO1995005733A1

WO1995005733A1 - Milking unit removal device

Info

Publication number: WO1995005733A1
Application number: PCT/SE1994/000775
Authority: WO
Inventors: Hans Kristoffer Olofsson
Original assignee: Tetra Laval Holdings & Finance S.A.
Priority date: 1993-08-27
Filing date: 1994-08-25
Publication date: 1995-03-02
Also published as: SE9302774L; AU7626394A; SE9302774D0

Abstract

A removal device for automatic removal of a milking unit from an animal's teats after finished milking, comprising a cord, which at its one end is connected to a coupling device (17), which has at least two releasably connectible coupling members (19, 20) adapted to be disconnected from each other if a particular tensile stress arises in the cord. The coupling members are arranged such that a milk claw connected to the cord is securely disconnected therefrom when said tensile stress arises in the cord.

Description

Milking Unit Removal Device

The present invention relates to a removal device for automatic removal of a milking unit from the teats of an animal after finished milking, which milking unit has a milk claw with a number of teat cups connected thereto, the removal device comprising an actuation means, an elongated pulling means being adapted to be connected to the actuation means at one of its ends and to the mil- king unit at its other end, and a coupling means connec¬ ted to the pulling means, said coupling means having two releasably connectible coupling members and being adap¬ ted to disconnect the milking unit from the actuation means if a certain tensile stress arises in the pulling means.

Such a removal device is known from SE-B-453 217 which has the object to prevent the animal from kicking off the milking unit by means of the pulling means. The known removal device has a serious drawback, however, since the coupling device may be arranged anywhere bet¬ ween the ends of the pulling means, whereby the pulling means is divided into two parts. The pulling means is explicitely a cord. This means that an animal, for example a cow, trying to relieve herself from a milking unit, which is attached to the animal's udder, will be able to disconnect the coupling members from one another if the cow for example gets different parts of the cord entangled in her legs and, thereby, causes said tensile stress to arise in the cord. If the milk unit falls down from the udder to the floor and the cow gets entangled in the part of the cord, which extends between the milk claw and one of the coupling members of the coupling means, there is a risk that the cow steps on the milking unit so that it gets damaged. The milker can then only with great difficulty release the milk claw from the legs of the cow.

Besides, the known coupling means requires that great care is taken each time the coupling members are manual¬ ly connected, since a particular release tension must be set.

Another known removal device, described in WO 93/00002, comprises an ordinary spring hook connected between the milking unit and the pulling means. For this reason the latter may only be manually disconnected from the mil¬ king unit,

An object of the present invention is to provide a removal device for a milking unit, which protects the milking unit better than conventional removal devices from harmful influence by the animal during milking.

Another object of the invention is to provide a removal device which allows automatic as well as manual dis¬ connection of the removal device from the milking unit.

Yet another object of the invention is to provide a removal device which admits easy coupling of the removal device and the milking unit after disconnection.

These objects are achieved by means of a removal device of the initially described kind, which is characterized in that the coupling means is situated between the pulling means and the milk claw, a first one of the coupling members being connected to said second end of the pulling means and a second one of the coupling members being adapted to be connected to the milk claw such that the milk claw is securily disconnected from the pulling means when said tensile stress arises in the pulling means.

By means of a removal device according to the invention it is possible for the milk claw to get automatically disconnected from the actuation means irrespective of which part of the pulling means is subjected to an un- desired large tensile stress by the cow or by something else.

According to a preferred embodiment of the invention the said second coupling member comprises two clamp members, which are situated at a distance from each other, and said first coupling member is dimensioned such that it is insertible in one direction between the two clamp members and is adapted after turning thereof to be clutched between the clamp members by a predetermined force when situated between the same, but when this force is overcome, i.e. when said tensile stress arises in the pulling means, to be released from the clamp members.

The clamp members are suitably formed by a clamp made in one piece and adapted to be releasably connected to said milk claw.

Preferably a guide member is provided both to guide the first coupling member while the latter is turned in relation to the clamp members such that the turning is obtained about a predetermined axis of rotation, and to prevent movement of the first coupling member between the clamp members in a direction across said axis of rotation. The said direction for introduction of the first coupling member between the clamp members substantially corresponds to the direction of said axis of rotation. Furthermore, the first coupling member preferably is provided with a projection extending in alignment with said axis of rotation and being insertible into a recess in the guide member in such a way that a relative tur¬ ning between the first coupling member and the guide member is made possible.

Preferably, the guide member comprises a loop, which is connected to the milk claw.

The invention will now be described in more detail with reference to the annexed drawings, in which

Figure 1 shows a milking equipment with a removal device according to the invention,

Figure 2A is a side view of a part of the removal device according to figure 1, comprising two coupling members connected to each other, in the form of a turning knob and a clamp,

Figure 2B shows a view of a cross-section along the line IIB-IIB in figure 2A,

Figure 2C shows the same view as in figure 2B but with the turning knob omitted,

Figure 3A shows a front view of the turning knob,

Figure 3B shows a side view of the turning knob, Figure 3C shows a view of a cross-section along the line IIIC-IIIC in figure 3B, and

Figure 4 is a perspective view of the clamp.

Figure 1 shows a milking equipment comprising a stand 1, to which a control means 2 is attached. A hook 3 is arranged on the stand for enabling a comfortable suspen¬ sion of the milking equipment on existing vacuum and milk pipelines 4, 5 in the milking room. From a milking unit 6, comprising four teat cups 7 and a milk claw 8 a milk tube 9 and a pulsation tube 10 extend to a milk flow meter 11 and a pulsator 12, respectively, which are supported by the stand 1. From the milk flow meter 11 and the pulsator 12 a milk tube 13 and an air tube 14 extend in their turn upwards to a coupling means 15, which is arranged on the milk pipeline 5. The upper ends of the tubes 13, 14 are provided with means 15a for a quick connection of the same to the connection means 15, which is adapted to connect the tubes 13, 14 to the milk pipeline 5 and the vacuum pipeline 4, respectively.

The milking equipment is further provided with a removal device for automatic removal of the milking unit 6 from an animal's teats after finished milking.

The removal device comprises an elongated, flexible pulling means in the form of a cord 16, a coupling device 17 and an actuation device in the form of a pneumatically drivable sliding vane motor 18, e.g. of the kind described in WO 93/00002. The actuation means may alternatively be constituted of a pneumatic cylinder with a piston (see US-A-3 814 056), an electric motor, a spiral spring (see DD 233 480) or any other suitable device. Figures 2A and 2B show the coupling device 17 comprising two releasably connectible coupling members, one of which having the form of a turning knob 19, which is adapted to be connected to the pulling means at its one end, while the other coupling means comprises a clamp 20 and a guide member in the form of a loop 21, which is connected to the milk claw 8.

Figure 2C shows the clamp 20 provided on the loop 21 in the case when the turning knob 19 is not connected to the clamp.

In the following the turning knob 19 will be closer described with reference to Figures 2B and 3A-3D.

Coaxially with an axis of rotation S of the turning knob 19 this is provided with a through-going hole 22, the purpose of which is to serve as an attachment of the cord 16. Furthermore, the turning knob 19 forms a pro- truding member 23, which has two plane long sides 24a, 24b (see Figure 3A) and two dovetail shaped short sides 25a, 25b (see Figure 3B). In a section (IIIC-IIIC) across the axis S of the turning knob through the pro¬ truding member 23 (see Figure 3C), the member 23 presents a rectangular cross-section.

The clamp 20 comprises (see Figure 4) two identical, opposite, reversed clamp members 26, 27, each comprising two end parts 26a, 26b and 27a, 27b, each first end part 26a, 27a being plane and each second end part 26b, 27b being shaped to abut the dovetail shaped short sides 25a and 25b, respectively, of the turning knob's 19 protru¬ ding member 23 when the turning knob and the clamp are connected. The plane end parts 26a, 27a are connected to a connecting member 28 in such a way that the clamp members 26, 27 are substantially parallel with and situated at a distance from each other. The connecting member forms a blind end of the clamp. The opposite end of the clamp is open. The clamp is of a resilient material, for example spring steel or a suitable resilient plastic material, wherefore a particular resilience arises during movement of the clamp member away from each other at the open end of the clamp. The distance x between the clamp members and the open end of the clamp is larger than the distance y of the protru¬ ding member's 23 dovetail shaped short sides 25a, 25b of the turning knob 19 but is less than the distance z of the protruding member's plane long sides 24a, 24b. This enables free insertion of the protruding member 23 between the clamp members 26, 27 when the plane long sides 24a, 24b extend along the clamp members.

Furthermore, the turning knob has a finger grip in the form of a pair of wings 29 for enabling turning of the turning knob 19 about its axis of rotation S. For faci¬ litating said turning the turning knob is furthermore provided with a gliding plane 30 arranged across the turning knob's axis of rotation 21 and in such a way that the gliding plane 30 will abut an edge 31a, 31b of the clamp member's end parts 26b, 27b, respectively, at the open end of the clamp during turning and connection of the coupling parts 19, 20.

During connection of the coupling parts 19, 29 the glide plane 30 of the turning knob is placed against the clamp members' outmost edges 31a, 31b having the protruding member 23 of the turning knob placed between the clutch members 26, 27. Then the protruding member's plane long sides 24a, 24b face the clamp members 26, 27. While the turning knob 19 is being turned, two diametrically opposed corners 32a, 32c or 32b, 32d formed between the protruding member's 23 long and short sides 24a, 24b, 25a, 25b, touch the clamp members. During continued turning, the clamp members 26, 27 are forced outwards because the distance between two diametrically opposed corners 32a, 32c or 32b, 32d is larger than the distance x between the clamp members 26, 27. At completed turning, the protruding member^'s dovetail shaped short sides 25a, 25b face the clamp members 26, 27, the clamp members springing back a bit since the protruding member's long sides 24a, 24b are shorter than the distance between two diametrically opposed corners 32a, 32c or 32b, 32d.

As mentioned above the clamp 20 is connected to a loop 21. This has a narrow, rectangular cross section and a width, which is adapted such that the clamp members' end parts 26b, 27b may be releasably connected to the loop. Having the clamp 20 connected to the loop 21, this and the clamp member's end parts 26b, 27b form an opening of dovetail shape, which is shaped to fit the protruding member's dovetail shaped part (see Figures 2B and 3B) . The loop 21 is an integrated part of the milk claw 8. Alternatively, it may be releasably connected to the milk claw.

The loop 21 serves not only as a connection means for the clamp 20 to the milk claw 8 but also as a guide member for the turning knob 19 for facilitating positio- ning of the turning knob between the clamp members and to facilitate turning of the same. Hence, the loop 21 is provided with a recess having the shape of a circular hole 33 (see Figure 2C) for receiving a circular cylin¬ drical projection 34 of the turning knob 19, which projection is provided on the protruding member 23 coaxially with the axis of rotation S of the turning knob.

Alternatively, the clamp members 26, 27 may be directly connected to the milk claw by gluing, welding, riveting or the like of the clamp 20 to a suitable part of the milk claw 8. A separate guide member may be constituted of a plate which is fitted between the clamp members 26, 27 and is rigidly connected to one of them. During outward resilient movement of the clutch members the plate will move only in relation to the clamp member to which the plate is not connected. In analogy with the above described loop, also such a plate is provided with an opening for receiving the circular cylindrical projection 34 of the turning knob. The recess should in this case be oval so that the turning knob can be turned according to a desired turning pattern.

If a certain tensile stress arises in the cord 16, the protruding member's 23 dovetail shaped short sides 25a, 25b of the turning knob 19 forces at least one of the clamp members 26, 27 to spring away outwards from the turning knob such that it is disconnected from the clamp members. The clamp members' spring force, which substan- tially corresponds to the tensile stress intended to release the coupling device, is chosen differently depending on which type of animal the milking equipment is intended to be used for. Accordingly, a larger spring force must be chosen for cows than for sheep and goats.

Claims

1. A removal device for automatic removal of a milking unit ( 6) from the teats of an animal after finished milking, which milking unit (6) has a milk claw (8) with a number of teat cups connected thereto, the removal device comprising an actuation means (18), an elongated pulling means (16) being adapted to be connected to the actuation means (18) at one of its ends and to the mil- king unit (6) at its other end, and a coupling means

(17) connected to the pulling means (16), said coupling means having two releasably connectible coupling members (19, 20) and being adapted to disconnect the milking unit (6) from the actuation means (18) if a certain tensile stress arises in the pulling means (16), c h a r a c t e r i z e d i n that the coupling means (17) is situated between the pulling means (16) and the milk claw (8), a first one (19) of the coupling members being connected to said second end of the pulling means (16) and a second one (20) of the coupling members being adapted to be connected to the milk claw (8 ) such that the milk claw is securily disconnected from the pulling means (16) when said tensile stress arises in the pulling means.

2. A removal device according to claim 1, wherein said second coupling member (20) is adapted to be releasably connected to the milk claw (8) .

3. A removal device according to claim 1 or 2, wherein said second coupling member (20) comprises two clamp members (26, 27) which are situated at a distance from each other, and said first coupling member (19) is dimensioned such that it is insertible in one direction between the two clamp members (26, 27) and is adapted after turning thereof to be clutched between the clamp members (26, 27) by a predetermined force when being situated between the same, but when this force is over¬ come, i.e. when said tensile strength arises in the pulling means, to be released from the clamp members.

4. A removal device according to claim 3, wherein said clamp members (26, 27) are formed by a clamp (20) made in one piece.

5. A removal device according to claim 3 or 4, wherein a guide member (21) is provided both to guide the first coupling member ( 19 ) while the latter is turned in relation to the clamp members (26, 27) such that the turning thereof is obtained about a predetermined axis of rotation (S), and to prevent movement of the first coupling member between the clamp members in a direction across said axis of rotation (S).

6. A removal device according to claim 5, wherein said direction for introduction of the first coupling member (19) between the clamp members (26, 27) substan¬ tially corresponds to the direction of said axis of rotation (S) .

7. A removal device according to claim 5 or 6, wherein said first coupling member (19) is provided with a projection (34) extending in alignment with said axis of rotation (S) and being insertible into a recess (33) in the guide member in such a way that a relative turning between the first coupling member (19) and the guide member (21) is made possible.

8. A removal device according to any one of claims 5-7, wherein said guide member (21) is a loop, which is connected to the milk claw (8).

9. A removal device according to claim 8, wherein said loop (21) is an integrated part of the milk claw (8).