All About Permanent Magnetic Chuck

By Author: JASON CHEN
Total Articles: 41
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Over the electromagnet, applied to holding devices the permanent magnet has several inherent advantages. However, art in connection with standardized machinery when subjected to the full requirements of the developed, in several respects the permanent
Magnetic Chuck has thus far failed to equal the performance obtained from electro-magnetic devices.

This indicate both to the holding power and, at least, to that percentage of the total working surface in which an optimum of attractive force can be obtained, and also to the degree of facility with which work may be released and removed from the chuck.

Along with this it has been a characteristic of such chucks, as hitherto commercially employed, that the rim of the top plate framing the holding surface, differs itself in magnetic polarity from the bottom of the chuck and the machine to which it is at- 80 tached.

Around the chuck this produces an undesirable zone of attraction, resulting in causing accumulation of chips or sludge, and eventually a reduction of holding power, a condition ...
... that does not occur with the ordinary electro chuck, in which the top frame and its entire external support have identical polarity. Also, with age and use the permanent magnet chuck or

Magnetic Welding Holder of the prior art tends to deteriorate.

To overcome these shortcomings and to produce a permanent magnetic chuck it is the general object of the invention that in all important aspects will be equal to the electro chuck, while still retaining the special advantages incidental to the permanent magnet.

Provision of a permanent magnetic chuck is another object of the invention in which the holding power is greatly increased over prior art chucks of this type, and will even equal that of an electro chuck of similar size.

Another object is the provision of a permanent magnetic chuck which with age and use will not deteriorate; such deterioration in prior chucks is because of the displacement of a magnet with respect to a flux transmitting surface with which it is in discontinuous contact. In the present structure it can be avoided by keeping the magnets in fixed contact with the next contiguous flux transmitting members at all times.

Of a permanent magnetic chuck a further object is the provision in which the top and bottom plates are of the same polarity, and in which such plates are usually located in abutting relation, so that in the magnetic circuit the side walls of the Magnetic Chuck serve as a return path.

Another provision of a permanent magnet chuck is a still further object having a stationary magnet and a reversible magnet in which the latter is capable of parallel or series connection with the former, and the reversible magnet compared to the stationary magnet is equal to or greater in magnitude, so that when they are in series connection, the polarities of the work-holding members will be reversed, and work release and even partial demagnetization of the work will occur; and, when they are in parallel connection, the flux of both magnets will be additive and thus in the work holding circuit both will contribute to the flux.