Northern Telecom Limited

Amit Chawla

Balwantrai Mistry

John Clayton Atkinson

Adrianus P Van Gaal

Peter J Kielstra

Yee-Ning Chan

James K Adamson

Richard J Humphreys

Electronic unit in which a printed circuit board is located within a housing which includes a heat sink. The board is normally urged out of heat conductive relationship with the heat sink. As temperature increases the circuit board and heat sink are caused to move relatively so as to bring the board into heat conductive relationship with the heat sink so as to remove heat from the board. As temperature decreases the board and heat sink are again moved out of heat conductive relationship. Preferably a heat conduction element is provided to conduct heat from the board. This comprises at least one compressible member, e.g. compressible cellular material, which is progressively compressed as temperature increases. Preferably the heat conductive efficiency of the compressible member increases as compression increases.

Electronic unit

Within an electronic shelf, physically separating or isolating in a front to rear direction keying elements from connector alignment elements to provide a separation distance, minimizes the undesirable interaction that may occur between keying elements and connector alignment elements due to tolerance effects. Worst case manufacturing tolerances with respect to keying elements, for example, no longer influence in any significant way, the co-action of the connector alignment elements. Insertion of circuit packs into respective receiving stations is achieved with less effort since effort is not required to overcome extra frictional forces resulting from the keying elements interacting with the connector alignment elements. The separation distance between keying elements and connector alignment elements is made to be as large as possible so as to minimize the effects of keying elements opposing the repositioning of a circuit pack for connector alignment purposes by the connector alignment elements within a receiving station.

Electronic shelf keying and alignment combination

Growing community of inventors

Nepean, Canada

Amit Chawla