US 5903433

Patent Overview — US 5,903,433 A

Title: Cooling system for telecommunications equipment arranged in a cabinet or similar

Assignee: Telefonaktiebolaget LM Ericsson AB (original and current assignee listed)

Inventor: Bjorn Gudmundsson

Key dates: Priority 1994-12-14; filed 1995-12-11; granted/publication 1999-05-11; anticipated expiration 2015-12-11. Status shown as "Expired – Lifetime."

Purpose: Radio base stations emit large heat quantities (typically 1600–2500 W, up to 80% from radio transmitters). Existing approaches—filtered outdoor air, heat exchangers, or cooling machines—are bulky, costly, complex, or lack redundancy. The stated object is a cooling system that is functionally simple and readily installed, highly reliable, needs no additional fans, and operates at low cost.

Plain-language scope: The cabinet is divided into two spaces. Heat-intensive components (power units, radio transmitters, final stages—labeled A–D) sit in a first space inside EMC-shielded, hermetically closed boxes with external heat sinks. Ambient air enters the first space through an inlet, is guided by channels or conduits past the heat sinks, and exits via an outlet, driven by a fan. Lower-heat components (F) sit in a second hermetically closed space. Air circulates from that second space through channels to a compact heat exchanger (E) mounted in the first space, driven by a fan; the heat exchanger "need not have good efficiency," may be a transverse-flow type, and the two air flows may run in counterflow. The specification notes the second space could be enlarged, and the first space divided into sections, with components selectively arranged. Advantages claimed: roughly one-third size reduction, easier installation, lower complexity, and lower operating costs.

Source: https://patents.google.com/patent/US5903433/en

What the excerpt does not establish: It does not provide the full text of the claims, the claims' exact wording or scope, the complete description (text is excerpted/omitted), any drawing reference numerals beyond the schematic FIG. 1 discussion, or the contents of the abstract beyond what appears here. It lists only one embodiment and states the invention is not restricted thereto. No prosecution history, validity, or prior-art analysis is included.