Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2000-08-18
2001-09-04
Picard, Leo P. (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S688000, C361S689000, C361S690000, C361S721000, C361S759000, C361S802000, C361S818000, C174S015100, C174S016100, C174S066000, C174S067000, C312S223200, C439S079000, C454S184000
Reexamination Certificate
active
06285548
ABSTRACT:
BACKGROUND OF THE INVENTION
Electrical components generate an electromagnetic field when the electrical components are in an activated state. This electromagnetic field can be generated by an act as simple as a current passing through a wire. However, the concern related to the electromagnetic field creating interference is typically related to complex circuitry. This electromagnetic field generated by one component can interfere with the workings of other components in proximity to it. With this concern, various groups and organizations such as the Federal Communications Commission establish requirements regarding the emission of electromagnetic waves or fields from components or units, such as chassises. This emission of electromagnetic waves is typically referred to as electromagnetic interference or EMI.
It is known to create a metal cage surrounding the components to block or “knock down” the radiating electromagnetic waves. As the frequency within the circuitry increases the wavelength decreases, therefore the size of the opening through which the electromagnetic wave can exit the chassis is decreased. For example, as the frequency approaches 622 MHz, the size of the opening through which a wave may pass is in the range of 2 inches. While the height of the wave depends on the frequency, the width or thickness of the wave is infinitesimal. Therefore, while the opening needs to be approximately 2 inches in height for the frequency of approximately 622 MHZ to pass through, the opening could be the thickness of this paper and the wave could pass through.
While there is a desire to reduce the size of openings in the chassis containing the electronic components, there is still a need to access the components and a need to replace components or interchange components as desired. It is known to have a series of panels or plates, such as face plates, which are removable to grant access to a component such as a printed circuit board located within the unit. In addition, the face plate may include openings to allow connectors to be accessible and indicators, such as lights, to be visible from the outside of the unit.
In addition to the desire to limit the emission of electromagnetic waves from the component, there is a desire or need to expel heat from the unit. It is therefore a balance of apparently opposing goals to allow sufficient airflow through the unit to allow proper cooling while at the same time preventing the emission of electromagnetic waves.
SUMMARY OF THE INVENTION
The invention relates to an electronic chassis or modular rack having elements and methods for reducing emission of electromagnetic waves or interference (EMI) and at the same time ensuring that the components within the chassis or rack are properly cooled and accessible.
The invention relates to a face plate which attaches to a printed circuit board or blank board for insertion and removal of the board from the chassis and limiting EMI emission while allowing connector and indicator accessibility.
The invention relates to an air impedance module or board for limiting air flow therein allowing redirection of the flow.
The face plate according to the invention has an elongated frame having at least two planar body portions. Each planar portion has a pair of planar surfaces and a pair of side edges. The planar body portions are integrally formed to each other with the planes of the two planar body portions at an angle of between 25 and 55 degrees of each other. The elongated frame has a pair of free edges adjacent to the planar surfaces and the pair of side edges. The face plate has a pair of mounting devices. Each mounting device is carried by the elongated frame in proximity to one of the free edges. The pair of mounting devices are offset from each other in parallel planes parallel to one of the planar body portions.
In a preferred embodiment, the face plate has a plurality of mounting bosses or printed circuit mounts carried on the inner surface of the planar body portions for attachment to a front edge of a printed circuit board. The mounting devices include at least one ejector pivotably mounted to the face plate adapted for seating and securing the face plate to a chassis. The planar portion of the elongated frame has an integral protrusion on the outer surface for pivotably receiving the ejector.
In a preferred embodiment, the face plate has an opening on one of the planar body portions adapted to receive an optical interface. In a preferred embodiment, the optical interface is an optical transceiver.
In a preferred embodiment, the elongated frame of the face plate is die cast. The planar portion of the elongated frame has an integral die cast protrusion on the outer surface for pivotably mounting an ejector adapted for seating and securing the face plate to a chassis. One of the side edges of the elongated frame has a flange with a groove. The groove receives a metallic seal adapted to seal with an adjacent surface.
The invention relates to a board for insertion in a chassis for controlling air flow in the chassis. The board has a planar portion having a pair of sides and a plurality of edges. The top and bottom edges are adapted to be received in the chassis. An air impedance protrusion is formed integrally with the planar portion and is adapted for limiting the flow of air. The limiting of the flow of air in one portion results in the air being redirected to the printed circuit boards that have active components that need to be cooled.
In a preferred embodiment, the air impedance board has a plurality of air impedance protrusions formed integrally with the planar portion of the chassis and protruding from the planar portion on the same side for limiting the flow of air. The board has a stiffener protrusion projecting generally non-parallel to the air impedance protrusion.
In a preferred embodiment, the air impedance board is formed of a flame retardant thermoplastic such as Kydex-T. In a preferred embodiment, the electronic chassis has a fan tray with a plurality of slots underlying the fan blades to allow air to flow through and is solid under the hub for fire protection purposes.
REFERENCES:
patent: Re. 34955 (1995-05-01), Anton et al.
patent: D. 379290 (1997-05-01), Joslin
patent: 4064551 (1977-12-01), Lightfoot
patent: 4092699 (1978-05-01), Petrangelo
patent: 4233646 (1980-11-01), Leung et al.
patent: 4313150 (1982-01-01), Chu
patent: 4564250 (1986-01-01), Klein et al.
patent: 4580192 (1986-04-01), Beun
patent: 4603375 (1986-07-01), Miller et al.
patent: 4648009 (1987-03-01), Beun et al.
patent: 4716497 (1987-12-01), Craker
patent: 4725921 (1988-02-01), Scholz
patent: 4840570 (1989-06-01), Mahnn, Jr. et al.
patent: 4996631 (1991-02-01), Freehauf
patent: 5011257 (1991-04-01), Wettengel et al.
patent: 5216578 (1993-06-01), Zenitani et al.
patent: 5255160 (1993-10-01), Iwatare et al.
patent: 5267658 (1993-12-01), Schwenk et al.
patent: 5302133 (1994-04-01), Tondreault
patent: 5309325 (1994-05-01), Dreher et al.
patent: 5375724 (1994-12-01), Mazura
patent: 5402319 (1995-03-01), Shumaker et al.
patent: 5406455 (1995-04-01), Devenish, III
patent: 5410448 (1995-04-01), Barker, III et al.
patent: 5428507 (1995-06-01), Chatel et al.
patent: 5432674 (1995-07-01), Hardt
patent: 5638259 (1997-06-01), McCarthy et al.
patent: 5669512 (1997-09-01), Joslin
patent: 5680294 (1997-10-01), Stora et al.
patent: 5708742 (1998-01-01), Beun et al.
patent: 5724467 (1998-03-01), vandenEnden et al.
patent: 5781417 (1998-07-01), Albani et al.
patent: 5793614 (1998-08-01), Tollbom
patent: 5801926 (1998-09-01), Cutsforth et al.
patent: 5930120 (1999-07-01), Gunther et al.
patent: 5945633 (1999-08-01), Ott et al.
patent: 5946196 (1999-08-01), Baek
patent: 5978233 (1999-11-01), Roscoe et al.
patent: 5999411 (1999-12-01), Patel
patent: 6003689 (1999-12-01), Babineau et al.
patent: 6160717 (2000-12-01), Desousa et al.
patent: 6172880 (2001-01-01), Petitpierre et al.
patent: 6185106 (2001-02-01), Mueller
Franklin Eric G.
Hamlet Darrel J.
Chervinsky Boris L.
Hamilton Brook Smith & Reynolds P.C.
Picard Leo P.
Quantum Bridge Communications Inc.
LandOfFree
Face plate for a chassis for high frequency components does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Face plate for a chassis for high frequency components, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Face plate for a chassis for high frequency components will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2434809