Detecting arrangement and method for a magnetic gripper device

#The present invention generally relates to the field of animal arrangements, preferably but not exclusively intended for cows, and more specifically the invention relates to detecting arrangements and methods according to the preambles of the appended independent patent claims.

#Electromagnets may be used for gripping and holding parts made of a magnetic material.

#WO 00/72665 A1 (DELAVAL), EP 0 551 956 A1 (VAN DER LELY), and WO 96/07314 (MAASLAND) disclose the use of electromagnets in gripper devices for milking robots. The gripper devices are used for gripping teat cups and attaching them to the teats of a cow.

#FIG. 1 illustrates, in a perspective view, a milking station comprising a milking robot including a magnetic gripper device with a detecting arrangement according to an embodiment of the present invention.

#FIG. 2 illustrates, in a schematic side view, the magnetic gripper device with the detecting arrangement as being comprised in the milking robot of FIG. 1.

#FIGS. 3a-b are current diagrams for a magnetic gripper device operated with AC and DC currents, respectively, during gripping of a teat cup by the magnetic gripper device as detected by the detecting arrangement of FIG. 2.

#In FIG. 1 is shown a milking system or station arranged for voluntary milking of freely walking animals such as e.g. cows, i.e. the animals enter the milking station 9 in order to be milked on a voluntary basis. The milking station 9 comprises an enclosure having an inlet gate 11 and an outlet gate 12.

#An automatic milking machine (not explicitly illustrated) is provided for milking the cows. The automatic milking machine includes teat cups 5 connected to an end unit by means of milk lines (only the portions attached to the teat cups 5 are shown in FIG. 1).

#A milking robot or automatic handling device 2 having a robot arm 10 equipped with a magnetic gripper device 3 in its far end is provided to automatically fetch the teat cups 5 of the milking machine from a rack 4, wherein the teat cups 5 are stored, to move them toward the udder of the cow, and to attach them to the teats of the cow. Typically the teat cups 5 are fetched, moved and attached one at a time. However, they may alternatively be fetched, moved and attached two or all at a time.