US 3312769 A
Description (OCR text may contain errors)
April 4, 1967 E. P. LA KAFF 3,312,769 R-F. SEAL! FOR ELECTROMAGNETIC WAVE RADIATION SHIELDING ENCLOSURE Filed 00%. 29, 1965 2 Sheets-Sheet 1 INVENTOR Edward P. Lu Kuff ATTORNEY April 4, 1967 E. P. LA KAFF 3,
' R F SEAL FOR ELECTROMAGNETIC WAVE RADIATION SHIELDING ENCLOSURE 2 Sheets-Sheet 2 Filed Oct. 29, 1965 mGE INVENTOR Edward P. Lo Koff ATTORNEY United States Patent 3,312,769 R.F. SEAL FOR ELECTROMAGNETIC WAVE RADI- ATION SHIELDING ENCLOSURE Edward Peter La Kali, Corvallis, Oreg., assignor to Borg- Warner Corporation, Chicago, Ill., a corporation of Illinois Filed Oct. 29, 1965, Ser. No. 505,678 9 Claims. (Cl. 17435) .This invention relates to electromagnetic wave radiation shielding of enclosures and more particularly to shielding means for the joints of adjacent panels of radio frequency shielding enclosures.
A principal object of the invention is to provide a radio frequency shielding strip assembly for the joints between adjacent panels of a radio frequency shielding enclosure in which the panels are of easily deformable sheet material.
Another object of the invention is to provide a shielding apparatus for the joints of shielding panels in which shielding material is brought to bear against the adjacent marginal edges of adjacent panels despite the tendency of the panel edges to deform and become displaced with re spect to each other.
A further object of the invention is to provide shielding apparatus of the stated type wherein means are provided for efiecting a continuous sealing pressure throughout the length of the panel edges with the pressure being applied only at spaced points.
Another object of the invention is to provide electromagnetic wave shielding apparatus for the joints of adjacent panels of a radio frequency shielding enclosure in which the shielding material is resiliently biased into conductive relation with the adjacent marginal edges of adjacent shielding panels.
These and other objects of the invention will become more apparent as the description proceeds with reference to the accompanying drawings, in which:
FIGURE 1 is a view in perspective of a shielding strip assembly made in accordance with the present invention and illustrated in operative relation to supporting surfaces;
FIGURE 2 is an elevational sectional view taken substantially on line 22 of FIGURE 1;
FIGURE 3 is a plan view, partly in section, of a shielding strip assembly made in accordance with the present invention;
FIGURE 4 is a front elevational view of the strip assembly of FIGURE 3;
FIGURE 5 is a sectional plan view of a modified form of a mounting angle for the shielding strip assembly of the present invention;
FIGURE 6 is a view similar to FIGURE 3 but showing a modified form of the present invention; and,
FIGURE 7 is a vertical sectional view taken substantially on line 77 of FIGURE 6.
Referring to the drawings and more particularly to FIGURES l and 2 the shielding strip assembly of the present invention is indicated generally by reference numeral 10 and includes a mounting member 12, which is illustrated as being of channel configuration, and has a plurality of threaded openings 14 for reception of set screw 16. Secured to the outside surface of the base of the mounting member 12, at each end, is a channel member 18 of relatively thin sheet metal, such as stainless steel or the like. 18, and extending beyond the ends thereof as clearly illustrated in FIGURE 1, is a resilient core 20, desirably of neoprene sponge or the like, which is surrounded by a metallic mesh 22, of an alloy of nickel and copper such as of Monel metal or the like.
A pair of T-shaped brackets 24 each having a tang 26 may be secured, by any suitable means, to a suitable sup- Mounted within'the channel member "Ice 2 porting surface in spaced relation to the ends of a panel joint after the tangs 26 have been received within the ends of the channel member 18, as illustrated in FIG- URE 4. The channel member 18 is secured, as by spot welding or the like, at each end to the mounting member 12. The entire expanse of the channel member between the spot welds may be bowed away from the channel member 12 by tightening the screws 16 to bring the mesh 22 into resilient conductive relation with the marginal edges of panels 26 and 28, as illustrated clearly in FIG- URE 2. An important advantage of this construction is that pressure on the channel member is exerted only at spaced points but the pressure of the mesh 22 tends to be continuous throughout the length of the marginal edges of the panels. In this way, there are no gaps for possible leakage of radio frequency radiation.
In FIGURES 3 and 4 is illustrated an elevational view of the shielding strip of the invention illustrating clearly the manner in which the channel member 18 is forced into engagement with the marginal edges of a panel illustrated in dot and dash lines. The brackets 24 may be shaped to conform to any desired use. FIGURE 3 illustrates the brackets 24 as being secured, by means of cap screws 30 to an L-shaped frame member 32. In FIG- URE 5 is illustrated an alternate form of frame member to which the brackets 24 may be secured.
In FIGURES 6 and 7 is illustrated a modified form of the present invention in which a support member 12a is utilized in lieu of the support member 12 of the principal form of the invention. The support member 12a is of tubular construction, substantially rectangular in crosssection and functions much in the same manner as support member 12. In FIGURES 6 and 7 like reference numerals refer to like parts in the principal form of the invention. The support member may be particularly useful in instances where the enclosure panels are of limited thickness such as in the order of t" and the like.
The shielding device of the present invention exhibits important advantages over shielding devices heretofore known. For instance, the flexibility of the channel member ,18 and the action of the screws 16 permits the mesh 22 to be resiliently biased into electrically conductive engagement with the marginal edges of adjacent enclosure panels despite a tendency of the panels to depart from the same plane. A continuous shielding pressure is maintained throughout the length of the marginal edges of the panel with pressure exerted only at .spaced points throughout the length of the channel member 18. The support members .12 and 12a, besides providing reaction points for the screws 16, function to provide additional rigidity to the entire joint. It will be appreciated that metals other than Monel may be substituted in the mesh 22. So also, other metals may be substituted for the stainless steel of the channel member 18 and other resilient materials, such as polyurethane foam, may be substituted for the neoprene of the core 20.
It is to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.
What is claimed is:
1. Apparatus for sealing joints of adjacent panels of an electromagnetic wave radiation shielding enclosure comprising an elongated mounting member, a channel member secured to said mounting member, resilient core mounted in said channel member, a metallic mesh surrounding said resilient core, and means for biasing said channel member away from said mounting member so that said mesh-clad core is forced into conductive relation with the marginal edges of adjacent panels when said panels are brought into contact therewith.
2. A sealing assembly for the joints of adjacent panels of an electromagnetic wave radiation shielding enclosure comprising a body portion having a mounting member, a channel member secured to said mounting member at each end thereof, a pair of T-shaped brackets adapted to be secured to a supporting surface and each having a tab adapted to be received in an end of said channel member, a resilient core disposed in said channel member, a metallic mesh surrounding said resilient core, and means for displacing said channel member with respect to said mounting member so that the metallic mesh is brought into resilient engagement with the marginal edges of the panels throughout the length of the joint when said panels are brought into contact therewith.
3. A shielding strip assembly in accordance with claim 2, wherein said last-named means comprises a plurality of screws threadably received in said mounting member in longitudinally spaced relation, said screws being in abutment with said channel member so as to bias said channel member away from said mounting member and into firmelectrically conductive relation to the marginal edges of enclosure panels. 1
4. A shielding strip assembly in accordance with claim 2, wherein said tangs are secured to said channel member.
5. A strip assembly in accordance with claim 4, wherein said resilient core is of neoprene and the like.
6. A shielding strip assembly in accordance with claim 5, wherein said channel member is of stainless steel and the like.
7. A shielding strip assembly in accordance with claim 5, wherein said mounting member is of channel crosssection.
8. A shielding strip assembly in accordance with claim 5, wherein said mounting member is tubular and of rectangular cross-section.
9. A shielding strip assembly in accordance with claim 2, wherein said mesh is an alloy of nickel and copper.
LEWIS H. MYERS, Primary Examiner.
D. L. CLAY, Examiner