Liquid circulation system for cooling a laser head

United States Patent m

Connors et al.

US00578I574A [ii] Patent Number: [45] Date of Patent:

5,781,574 Jul. 14, 1998

[54] LIQUID CIRCULATION SYSTEM FOR COOLING A LASER HEAD

[75] Inventors: Kevin P. Connors. Sunnyvale; James L. Hobart. Los Altos Hills; Edward D. Reed. Sunnyvale; David Trost. San Francisco, all of Calif.; Kenneth J. Bossie. Tucson. Ariz.; Thomas William McCurnin. Tucson. Ariz.: Gerald M. Mitchell. Tucson. Ariz.; J. Michael Yarborough. Tucson. Ariz.

[73] Assignee: Coherent, Inc.. Santa Clara, Calif.

[21] Appl. No.: 873,823
[22] Filed: Jun. 12,1997

Related U.S. Application Data

[62] Division of Ser. No. 331,359, Oct. 27, 1994, Pat. No. 5,659,563, which is a division of Ser. No. 57,084, May 5, 1993, Pat. No. 5,375,132.

[51] Int. CI.6 HOIS 3/04

[52] U.S. CI 372/35; 372/34; 165/D1G. 303;

165/DIG. 314

[58] Field of Search 372/34-36. 20.

372/23. 109; 165/80.3. 80.4, 80.5. 104.33. 122. 125. 120. DIG. 303. DIG. 306. DIG. 314

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Primary Examiner—Hemang Sanghavi

Attorney, Agent, or Firm—Limbach & Limbach L.L.P.

[57] ABSTRACT

A liquid circulation system for cooling a laser head is disclosed. The circulation system comprises a main storage tank for holding a cooling liquid and a pump for circulating the liquid from the tank through the laser head and back into the tank. The cooling system includes a heat exchanger for cooling the liquid. The heat exchanger includes liquid carrying coils and an impeller fan rotatable about an axis. The fan being located adjacent the coils for drawing air across the coils in an axial direction with respect to the fan and for expelling the air radially with respect to the fan.

8 Claims, 13 Drawing Sheets

Page 2

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