a milking set 1 ( fig1 ) comprises four milking cups 2 which are arranged or fitted on teats of an udder u and which are coupled via a distributor piece 3 to a conduit 4 for generating pressure pulses and a drain conduit 5 for carrying off milk . the milking cups 2 are provided on the upper part with downward movable pulling means 6 which can be operated mechanically , pneumatically or hydraulically , or even manually . as can be seen in fig2 a and 2b , a flexible member 7 is arranged on the top of a milking cup 2 , which member is fixed to the pulling means 6 between a lower ring part 8 and an upper ring part 9 . the flexible member 7 preferably consists of rubbery material of small thickness , while the opening o therein for a teat , the teat being not shown in fig2 a and 2b , is enclosed by an annular portion 10 of slightly greater thickness . the present invention is not restricted to the embodiment shown , wherein the annular portion 10 has a slightly greater thickness . in accordance with the locally desired properties of the flexible member it can be adapted locally in respect of hardness properties , resilience etc ., for instance by means of the manner of vulcanization at that location . the flexible member 7 is arranged over an annular guide member 11 . the materials of the guide member 11 on the one hand and the flexible member on the other are preferably chosen such that they can slide easily over one another . one of the two may thus be made of teflon ™ and the other of , for instance , rubbery material . in addition , schematically depicted sensors 12 are preferably arranged in the guide member 11 , for instance to sense the presence or absence of a teat . during milking the milking cup will be situated in the position shown in fig2 a , wherein the opening o in the flexible member 7 seals round a teat , while as a result of pressure pulses in the annular space r between a stiff outer wall 13 and a flexible inner wall 14 a milking movement is performed on the teat , while the milk is carried away via a hose 15 . since the space directly beneath the opening o is slightly wider than the cylindrical space as defined by the flexible wall 14 and located further downward , a so - called vacuum buffer is created in the upper part of the milking cup , which considerably reduces the chance of the milking cup falling off the teat . when the milking cup 2 is placed around a teat it is brought into the position shown in fig2 b , preferably by bringing under pressure via line 18 an annular space s on the outside of the stiff wall 13 . when the space s is brought under pressure the pulling means 6 are moved downward and thus exert a pulling force on the flexible member 7 , wherein a considerably larger opening for introduction of a teat is enclosed by the rim 10 . the movement of the pulling means 6 are preferably bounded by stops 16 and 17 . the diameter of the opening is , for instance , variable between 18 and 45 mm . when pressure is removed in the space s the flexible member is once again returned by its resilience to the position shown in fig2 a . the guide member 11 preferably has the form of a truncated cone or sphere so as to prevent folds forming in the flexible member 7 . shown in fig3 is an embodiment of a guide member 20 that is provided with recesses 21 between partitions 21 &# 39 ;, which prevents a teat adhering to the guide member when it is inserted and possibly being folded double . many variations are possible within the scope of the above embodiment . it will , for instance , be apparent that the ring parts 8 , 9 ( fig2 a , 2b ) protruding slightly from the milking cup may cause problems in practice in that different milking cups in a milking set may hook together . another fixing of the bottom end of the flexible member can therefore be recommended . a further embodiment of a milking cup 22 ( fig4 ) is provided with a unitary part 23 of rubber material which forms the inner wall or lining 24 for exerting a milking movement to the teat t of a cow , and also forming a flexible member at the upper part of the cup and provided with the opening for the teat . the pulsating underpressure for milking is provided through line 25 between the lining 24 and an outer casing 26 of the cup . milk ( and cleaning water ) is sucked off through line 27 . unitary member 23 is provided with a shoulder 28 that fits under a bracket 29 . the unitary member or part 23 is provided with an upper part 30 in which the opening for a teat is included . in rest position ( fig5 ) the cup 22 shows an opening of normal size which fits nicely around the teat in customary fashion , without exerting any additional force on the teat . when applying the cup the opening is widened by exerting a pulling force to an outer circumferential flange 31 of the rubber part 23 . in the shown preferred embodiment an annular space 32 is provided around outer casing 26 , which space is sealed by rings 33 , 34 and into which a line 35 debouches . when medium is pressurized into space 32 a sleeve 37 is moved in upward direction together with the flange 31 . thereby the opening is widened as ring shaped hinge 36 is moved in outwardly radial direction . this hinge 36 is preferably formed by a thinned portion of the rubber material . preferably parts 38 and / or 39 are reinforced or stiffened e . g . by embedding rings into unitary part 23 , such that starting from those parts 38 , 39 a force urges ring shaped hinge 36 in outward direction , thereby widening the upper opening in an even , circular way . the above may very well be accomplished by correctly dimensioning parts 36 and 37 , 38 respectively . the inner construction of the cups remain basically unchanged ; pulling means are provided outside the cup itself the inner construction remain very compact , meaning that it is prevented that cups form a milking set which interfere with each other the inventive cups require very few new parts , such that they are cost effective .
a milking cup comprising a flexible member provided with an opening for a teat on the top part thereof and pulling mechanism which is movable from a rest position in order to exert a pulling force on the flexible member for the purpose of enlarging the opening therein , wherein the flexible member is fixed to the pulling means , such that the pulling force engages at least partly evenly along the periphery of the flexible member .