US 1875968 A
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Sept. 6, 193-2. 1 I 0, wEEBER STATIC AND MAGNETIC SHIELD Filed June 18, 1930 INVENTOR OTWER BY ATTORNEY Patented Sept. 6, 1932 UNITED STATES PATENT OFFICE OTTO WEEBER, OF BERLIN-CHABLQTTENBUBG, GERMANY, ASSIGNOR '10 SIEMENS & HALSKE, AKTIENGESELLSCHAI'T, O1 SIEHENSSTAD'I. NEAR BERLIN, GERMANY, A
coaroaa'rron or'enaum STATIC AND MAGNETIC SHIELD Application filed June 18, 1980, Serial ll'o.
This invention relates generally to shielding devices and more particularly to a shield construction utilizing layers of different materials.
The use of co per as working material for the shielding o self-induction coils or other v parts of radio circuits against the influence in the form of a cylinder havin of external electric fields is well known. When dimensioning the thickness of the coper sheets it was found that the sheet had to made of a greater thickness than reallynecessary for shielding purposes due to the demands of mechanical strength. Since copper sheeting is very expensive and since, for instance in radio receiving apparatus with several tubes, considerable quantities of copper sheeting had to be employed for the shieldin of the individual self-induction coils an other'parts a considerable increase in the cost of the receivers would result.
It is, therefore, an object of my invention to greatly cut down the cost of radio receivers and other radio apparatus in general by constructing the shield of preferably two materials one known for its chea ness and strength and the other for its go shielding properties.
Other objects of the invention will be apparent in the followin specification when read together with the rawing, the two fi ures of which illustrate schematically a shie (1 made in accordance with the invention.
According to this invention there is used, say, instead of pure copper sheetin aluminum sheeting which 1s coated wit co per. The copper coatin may for instance applied by means of e ectrolysis, but more suitably by means of rolling on, since this is cheaper. It is possible in this manner to combine the small thickness'of, say for in stance, the copper wall necessary for the shielding with sufiicient mechanical stability. When using copperplated sheets covered on both sides there result further electrical advantages which show up particularly in the case of lower frequencies.
In the drawing, a deeply drawn body 1 a closed end terminates in a flange 2 which is rovided with holes 3, 4 forthe mounting. lhe
401,927, and in Germany June 1a, 1929.
flange 2 may be integral with the body porit is evident that any combination of elements or materials may be used as for instance aluminum electroplated with zinc, sheet iron or steel and copper or in fact any usual plating material.
1. Static shield particularly for self-induction coils, and of special advantage in radio receiving arrangements, characterized in that itconsists of copper coated aluminum sheeting.
2. Shield according to claim 1, characterized in that the copper coating is disposed on both sides of the sheet.
3. An electromagnetic shield adapted to limit the field roduced by an element used in radio signal ing and to prevent said element from being affected by other electrical fields originating in the vicinity thereof comprising, a shield c0mp0sed ;pf a layer of nonferrous metal which has a" specific gravity constant substantially less than the specific gravity constant of copper, and a layer of highly conductive metal attached to said first named layer.
4. A shield as recited in claim 3 in. which the metal of said first named layer is of material shape retainin strength and said second named layer is 0 copper.
In testimony whereof I ailix my signature.