TEAT CUP GRIPPING MEANS

Abstract: The present invention relates to a teat cup (3) for use in a milking machine, wherein said teat cup (3) comprises an elongated housing (13) having a minimum width (Whmin), a top end (15) for receiving a teat (7) and a bottom end (19) wherein it is provided with at least one grippable means (29) suitable for being gripped by gripping surfaces (45', 45'') on a robot arm (11) wherein said grippable means (29) has a width in the transverse direction of said housing (13) which is less than the minimum width of said housing (13).

Description: Teat cup gripping means Technical Field of the Invention The present invention relates to a device and a method for gripping teat cups and the like in an automated rmlkiiig robot. Description of Related Art Automated milking robots are known which use a robot arm to sequentially attach teat cups to, for example, the teats of the animal being milked. A teat cup usually comprises a hollow cylindrical body with an open teat-receiving end. During use the teat cup is generally held with its longitudinal axis vertical and the robot arm is provided with gripping means such as a pair of opposed curved gripper plates or fingers which can grip around the circumference of the body of a vertically orientated teat cup. It can be a problem to provide a satisfactory gripping force with the gripper plates. On the one hand the gripper plates must grip sufficiently tightly so that when the teat cup is moved the teat cup is prevented from being pulled out from between the gripper plates due to the drag of the hoses attached to the teat cup. On the other hand the gripper plates must not grip too tightly as it is desirable that the teat cup be able to slide up and down, at least a small amount, between the gripping plates. This is because when the teat cup is being attached to a teat it is usual to provide an underpressure in the teat cup which causes the teat cup to suck itself up the teat as it approaches the teat from below. A problem can occur if a loosely held teat cup is not exactly positioned vertically below the teat because the teat cup will be pulled upwards at an inclined angle. The lateral forces and friction caused during this inclined pull can cause the teat cup to jam between the gripping plates and prevent a successful attachment of the teat cup to the teat. The jammed teat cup may also become difficult to release from between the gripping plates. A further problem with such gripping means is that, after releasmg a teat cup in order for the robot arm to be able to move to its next position, the tips of the gripping plates have to move sufficiently far apart so that the teat cup can pass between them i.e. the distance between the tips must be greater than the maximum diameter of the teat cup body in the gripping region. These spaced apart tips can catch on or bump against other teat cups as the robot arm is moved to its next position and can cause the teat cup to fall off the teat. Document SE,C, 40 233 discloses a teat cup provided with grippable means. However, if a robot arm is adapted to grip the grippable means on the teat cup the target for the robot arm is very small. Summary An object of the present invention is to provide a teat cup which overcomes the problems associated with gripping prior art teat cups. A further object of the invention is to provide a gripping means for a robot arm which overcomes the problems associated with gripping teat cups. In accordance with the invention a teat cup is provided with at least one grippable means suitable for being gripped by a robot arm wherein said grippable means has a width in the transverse direction of the teat cup housing which is less than the minimum width of the housing and that the grippable means is provided on a holder which surrounds said housing and which is movable in the longitudinal direction of said teat cup. This provides a gripping surface which the robot arm can grip onto without having to open its gripping means widely. This also provides a large target for the robot arm and can permit longitudinal displacements of the teat cup with respect to the robot arm. In accordance with another embodiment of the invention the gπppable means projects out beyond the surface of said housing. This reduces the distance that the robot arm has to move to reach the gπppable means. In accordance with another embodiment of the invention the grippable means projects substantially radially from said housing. This makes it easier for the robot arm to calculate where the gripping means is (or are) if only the position of the teat cup can be sensed by the robot arm or its control means. In accordance with another embodiment of the invention the grippable means extends in the longitudinal direction of said teat cup. The provides a large target for the robot arm and can permit the robot arm to still pick up the teat cup despite a possible small longitudinal misalignments of the grippable means with respect to the robot arm. In accordance with another embodiment of the invention the grippable means comprises a handle having an upper arm connected near to the top of said housing or holder, a lower arm connected near to the bottom of said housing or holder and an intermediate handle base connecting said upper arm to said lower arm. This provides a handle which defines an enclosed area which the gripping means can grip into without necessarily having to meet. In accordance with another embodiment of the invention the handle base is tapered and it has its maximum width or thickness nearer to said upper arm than to said lower arm. This allows some relative longitudinal movement between the gripping means and the teat cup and the height at which the robot arm grips the teat cup can be adjusted by setting the gap between the closed gripping means to correspond to the width of the handle at the desired gripping height. In accordance with another embodiment of the invention the upper arm is shorter that said lower arm so that the upper end of said handle base is closer to said housing or holder than the lower end of said handle base is. This provides a tapered area enclosed by the handle and allows some relative longitudinal movement between the gripping means and the teat cup. The height at which the robot arm grips the teat cup can be adjusted by setting the size of the closed gripping means to correspond to the size of taped area enclosed by the handle at the desired gripping height. A teat cup according to the invention is provided with one or more grippable projections which have a width which is less than the diameter of the teat cup. The projection is so arranged that a robot arm can grip on the projection which, being narrower than the teat body, means that the robot arm does not have to spread its gripping plates so wide when releasing the teat cup. Each grippable projection is advantageously provided with a elongated slot which extends substantially parallel to the longitudinal axis of the teat cup. The robot arm's gripping means can loosely surround the grippable projection and meet at the top of the slot which is wider than the width of the gripping means. The teat cup can hang free from the robot arm and can be sucked upwards until the gripping means come into contact with the bottom of the slot. In this way a sure grip on the teat cup is obtained at the same time the desired freedom of vertical movement is permitted. In accordance with the invention a gripping means is provided for gripping a teat cup in a milking machine. The gripping means has suction cup means adapted for gripping onto the body of said teat cup. This ensures that a positive grip is obtained on any suitable teat cup. In accordance with the invention an embodiment of a gripping means can grip with a suction cup onto a projection on said teat cup in order to provide good locating of the teat cup with respect to the gripping means. Brief Description of the Drawings The invention will now be described by way of examples of embodiments and with reference to the accompanying drawings in which: Figure 1 shows schematically a milking machine in which teat cups in accordance with the invention can be used; Figure 2 shows in perspective a first embodiment of a teat cup in accordance with the invention; Figure 3 shows in perspective a second embodiment of a teat cup in accordance with the invention; Figure 4 shows a lateral view of a third embodiment of a teat cup in accordance with the invention; Figure 5a) shows a lateral view of a fourth embodiment of a teat cup in accordance with the invention; Figure 5b) shows a view from above of the teat cup of figure 5a); Figure 6a) shows a lateral view of a fifth embodiment of a teat cup in accordance with the invention; Figure 6b) shows an end view of a part of gripping means on a robot arm for use with the embodiment of figure 6a); and Figure 6c) shows a view from above of a part of a gripping means on a robot arm for use with the embodiment of figure 6a). Figure 7a) shows a lateral view of an embodiment of a gripping means for gripping a teat cup; Figure 7b) shows a view from above of the gripping means of figure 7a). -> The figures are not drawn to scale and some parts are shown disproportionally large in order to improve understanding of the invention. Detailed Description of the Embodiments 0 Figure 1 shows a schematically a milking machine 1. Teat-cup 3 is intended to be moved, by a robot arm 11, from a cleaning and storage position 5 (where the robot arm 11 and teat cup are shown by dotted lines) where it is retained inverted to a rnilking position the right- way up on a teat 7 on the udder 9 of the animal being 5 milked. Figure 2 shows a first embodiment of a teat cup 3 in accordance with the present invention. Teat-cup 3 comprises an elongated cylindrical housing 13 of nrinimum width wi un n which has an upper end 15 where teat receiving means 17 are attached and a lower end 19 to which a fluid line 20 for milk, water and/or vacuum is attached. Surrounding housing 13 is a tubular sleeve or holder 21. Holder 21 has an inner diameter which is greater than the outside diameter of housing 13 and friction reducing means such as a low friction coating or a liner 23 is provided between the inner surface 25 of the holder 21 and the outer surface 27 of the housing 13. Holder 21 is provided with grippable means such as a projection 29 which projects radially out from the exterior surface 31 of holder 21. Projection 29 is in the form of a U- shaped handle 29 which is mounted with the base 33 of the U substantially parallel to the longitudinal axis of the teat cup 3. The upper arm 35 of the U-shaped handle 29 is attached to the end 37 of the holder 21 which is nearest to the upper end 15 of the teat cup and the lower arm 39 of the U-shaped handle 29 is attached to the end 41 of the holder 21 which is nearest to the lower end 19 of the teat cup. The U- shaped handle 29 encloses a void 43 which has a depth in the radial direction of the teat cup 3 which is determined by the lengths of the upper resp. lower arms 35, 39. The longitudinal length of void 43 is determined by the length of the base 33. The thickness of the material used for handle 29 is chosen such that the thickness of handle 29 is less that the outer diameter of housing 13. The size of void 43 is sufficiently large and the dimensions of the handle 29 are so chosen that gripping surfaces 45', 45" on robot arm 11 can encircle the base 33 of handle 29 and met in the void 43. In this way the gripping surfaces 45', 45" on robot arm 11 which are intended to move the teat cup by gripping on the handle 29 or by coming into contact with each other in void 43 do not have to open apart as much as they would have to if they were to grip around the width w hm i n of the housing 13. Thus the risk that the robot arm 11 comes into inadvertent contact with other teat cups already attached to the udder of the animal being milked is reduced. If the gripping surfaces 45', 45" of robot arm 11 are intended to grip onto handle 29 then it is possible to hold teat cup vertically and the risk of housing 13 jamming in holder 21 when teat cup 3 is sucked up onto a teat is minimise On the other hand if the gripping surfaces 45', 45" are intended to grip against each other in void 43 the teat cup can hang freely at an angle to the vertical. In order to prevent jamming when the teat cup is sucked up onto a teat the internal diameter of holder 21, the external diameter of housing 13, the radial width of any intermediate liner or coating 23 and the longitudinal length of holder 21 are chosen such that housing 13 and holder 21 are always substantially parallel. Additionally even if housing 13 does jam in holder 21 because of damage or wear it is still possible for teat cup 3 to be sucked upwards as the gripping surfaces 45', 45" can move vertically from a position in contact with upper arm 35 to a position in contact with lower arm 39. While above it is stated that gripping surfaces 45', 45" can grip against each other it is naturally also possible that they merely approach each other and have a gap between them which is less that the width of handle 29. Figure 3 shows a second embodiment of the invention in which holder 21 ' is provided with a plurality of handles 29'. This construction has the advantage that the robot arm can grip the teat cup from more orientations than is the case in the first embodiment. This embodiment has the disadvantage that the maximum width of the holder 21' and handles 29' is greater than in the case of the first embodiment. Figure 4 shows a third embodiment of the invention in which handles 59 are attached directly to teat cup housing 61. A handle 59 has an upper arm 63, a lower arm 65 and base 67 joining upper arm 63 to lower arm 65. Upper arm 63 and lower arm 65 are of substantially the same length so that base 67 is substantially parallel to the longitudinal axis of housing 61. As described above gripping surfaces of a robot arm (not shown) can grip onto each other in the void 69 formed between the handle and the housing 61 so that upper arm 63 rests on them and the teat cup hangs freely from them at an angle to the vertical. As mentioned above, housing 61 can be displaced vertically until the gripping surfaces come into contact with the lower arm to permit the teat cup to be sucked up onto a teat (not shown). Figure 5 shows a fourth embodiment of a teat cup in accordance with the invention in which the teat cup 70 can be held vertical while being gripped by a robot arm 71. Gripping surfaces 73', 73" on robot arm 71 have a cross-sectional shape S ghp which is adapted to lock into in a complementary shape S hand i e formed by the junction between the teat cup surface 75, upper arm 77 and base 79 of handle 81. Lower arm 83 of handle 81 projects out from the surface 75 further than upper arm 77 so that base 79 is no longer parallel with the longitudinal axis of teat cup 70. When gripping surfaces 73 ', 73 " are in contact with upper arm 77 the locked together complementary shapes S h a n die and Sgrip prevent rotation of teat cup 70 around the gripping surfaces 73', 73". When teat cup 70 is sucked upwards the complementary shapes unlock as gripping surfaces move into the progressively wider part of the void 85 which has a trapezoid shape. The increasing width of the void as the gripping surfaces 73', 73" move downwards reduces the contact area between gripping surface 73', 73" and the teat cup and handle resulting m reduced friction and also permitting the rotation of teat cup around the gripping surfaces 73', 73 without j amming . Figure 6 shows a fifth embodiment of a teat cup in accordance with the invention in which the teat cup 87 can be held in a desired orientation while being gripped by a robot arm 91. Gripping surfaces 93 ', 93" on robot arm 91 have a profile Pg nP which is adapted to lock into in a complementary profile of the handle P h a n die formed in the base 95 of handle 97. Base 95 is tapered so that it is wider in the transverse direction at the top than at the bottom. Upper arm 99 of handle 97 can be made wider than lower arm 101. Robot arm 91 has its gripping surfaces 93 ', 93 " positioned sufficiently close together so that they are in contact with both sides of the widest part of handle 97 when the teat cup is being moved by robot arm 91. When teat cup is sucked upwards the handle 97 is free to slide between the gripping surfaces as it tapers downwards. Thus the gripping surfaces 93'. 93" release their hold on the handle as it moves upwards. A further embodiment of the invention, not shown, is similar to the fifth embodiment with the difference that the thickness of said base varies in the radial direction instead of in the transverse direction. Figures 7a) and 7b) show a first embodiment of a gripper device 103 in accordance with the invention. Gripper device 103 is intended to be attached to the end of a robot arm (not shown) by appropriate fastening means (not shown). It comprises a body 105 having a recess 107 adapted to loosely fit onto a projection 115 on a teat cup 113. Inside recess 107 is a suction cup 109 connected to a suction pipe 111 which extends through body 105. The suction pipe can be connected to a vacuum supply (not shown). The gripper device 103 is intended to be moved towards a teat cup until suction cup 109 is in contact with a projection 112 on the teat cup 113. A vacuum is then applied to suction cup 109 via suction pipe 11 which causes suction cup 109 to grip onto the projection and thereby permits the robot arm to move the teat cup. When it is desired to release the teat cup the vacuum supply to the suction cup 109 is disconnected. Preferably body 105 has width which is less than the diameter of the teat cup 113 in the region it is intended to be gripped by. Figure 8a) shows a view from above of a second embodiment of a gripper device 103 ' which is intended to grip onto the curved surface of a teat cup 113'. The profile of recess 107' is adapted to the circumference of teat cup 113'. As can be seen from figure 8b), teat cup 113 ' can be provided with longitudinally spaced flanges 117 to guide and restrict the permitted longitudinal positioning of gripping means 103 '. Preferably body 105' has width which is less than the diameter of the teat cup 113' in the region it is intended to be gripped by. The various embodiments shown above can naturally be combined as necessary. As a non-limiting example it is conceivable to provide a teat cup with one or a plurality of handles having a tapered base and enclosing a trapezoidal void. The invention has been illustrated by means of teat cups having cylindrical bodies but it conceivable to apply the inventive concept to teat cups of any shape. While the invention has been illustrated by means of projecting grippable surfaces projecting radially, i.e. at right-angles from the surface of the teat cup it is possible to have them projecting at some other angle. It is also conceivable to provide a teat cup with grippable cavities, grooves, depressions or the like which a robot arm can be adapted to mate and grip with.

Claims: Claims 1. Teat cup for use in a milking machine, wherein said teat cup (3) comprises an elongated housing (13; 61) having a n inimum width (w^ m) , a top end (15) for receiving a teat (7) and a bottom end (19) said teat cup (3) is provided with at least one grippable means (29, 29'; 59; 81;97) suitable for being gripped by a robot arm (11; 71; 91) wherein said grippable means (29, 29'; 59; 81;97) has a width in the transverse direction of said housing (13; 61) which is less than the niinimum width of said housing (13; 61), characterized in that said grippable means (29,29' ;59;81:97) is provided on a holder (21;21') which surrounds said housing (13;61) and which is movable in the longitudinal direction of said teat cup (3). 2. Teat cup according to claim 1, characterized in that said grippable means (29, 29'; 59; 81;97) projects out beyond the surface (27) of said housing (13; 61). 3. Teat cup according to claim 2, characterized in that said grippable means (29, 29'; 59; 81;97) projects substantially radially from said housing (13; 61). 4. Teat cup according to any of the previous claims, characterized in that said grippable means (29, 29'; 59; 81;97) extends in the longitudinal direction of said teat cup (3). 5. Teat cup according to any of the previous claims, characterized in that said grippable means (29, 29'; 59; 81;97) comprises a handle (29; 29';59;81; 97) having an upper arm (35; 63; 77; 99) connected near to the top of said housing (13; 61) or holder (21; 21'), a lower arm (39; 65; 83; 101) connected near to the bottom of said housing (13; 61) or holder (21; 21 ') and an intermediate handle base (33; 67; 79; 95) connecting said upper arm (35; 63; 77; 99) to said lower arm (39; 65; 83; 101). 6. Teat cup according to claim 5, characterized in that said handle base (95) is tapered and it has its maximum width or thickness nearer to said upper arm (99) than to said lower arm (101). 7. Teat cup according to claim 5 or 6, characterized in that said upper arm (77) is shorter that said lower arm (83) so that the upper end of said handle base (79) is closer to said housing (13; 61) or holder (21; 21') than the lower end of said handle base (79) is. 8. Gripping means (103, 103') for gripping a teat cup (113, 113') a milking machine, characterized in that it has suction cup means (109) adapted for gripping onto said teat cup (113, 113'). 9. Gripping means (103, 103') in accordance with claim 8, characterized in that it has suction cup means (109) for gripping onto a projection ( 115) on said teat cup (113).

Inventors: CARLBAECK STURE, HOLMERTZ NILS-ERIK, CARLBAECK, STURE, HOLMERTZ, NILS-ERIK
Applicants: ALFA LAVAL AGRI AB, CARLBAECK STURE, HOLMERTZ NILS ERIK, CARLBAECK, STURE, HOLMERTZ, NILS-ERIK
Application year: 1999
Main classification: A01J5
IPC codes: A01J5