The present invention relates to a magnet device for animals, in particular cattle, and particularly to a magnet device adapted to be arranged in the stomach of cattle and to collect scrap iron pieces taken down in the stomach so that the scrap iron pieces are prevented from entering into the intestines.
Cattle grazing in meadows sometimes swallow grass nails, wires or the like falling on the ground. These scrap iron pieces remaining in the stomach are slightly dangerous for cattle, but when they enter into the intestines from the stomach, it causes a great danger which can be fatal to the cattle.
In order to prevent such a danger, there has been proposed a device which consists of a magnet formed in a bar or cylinder at a size to not enter into the intestines from the stomach and which is adapted to remain in the stomach of cattle thereby collecting scrap iron or the like invading into the stomach.
However, since such a device of a bar or cylinder magnet has magnetic pole portions limited to both end portions thereof, portion for performing a magnetizing function which collects the scrap irons is also limited to only both the end portions and its collecting effect has been insufficient.
In short, since the magnet device of this kind must remain in the stomach of cattle after the cattle has once swallowed it, without removing it out of the body of the cattle during its life, it was necessary to have the wide portion to magnetize scrap irons and to have a strong magnetizing force to magnetize the scrap irons.
The present invention is developed in the light of the above circumstances and in order to eliminate the above defects of the prior device, and contemplates to provide a magnet device which has the magnetizing portion not only at both ends but at peripheral wall portion and which has a magnetizing force intensified by concentrating flux of magnetic pole.
According to the present invention, a magnetic device is constituted by a plurality of magnets in a short cylinder shape having magnetic poles of polarity differing from each other at both end surfaces and piled in a longitudinal direction through the intermediary of at least a magnetic plate between each magnet, magnetic poles of the magnet opposing through the intermediary of the magnetic plate being the same polarity whereby the flux concentrates at the magnetic plate (yoke) portion and the magnetizing force increases.
Further, according to the invention, a magnet device is constituted by a plurality of magnets in a short cylinder shape having those outer diameter which are similar to or smaller than the outer diameter of magnetic plate, in order to decrease leakage flux and to effectively utilize the flux.
Other objects and features of the invention will appear in the following description taken with reference to the accompanying drawing.