Heat exchanger apparatus
United States Patent 3131758

Inventors:
Kern, Donald Q.
Hersam, Conrad O.
Publication Date:
05/05/1964
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Assignee:
Kern, Donald Q.
Hersam, Conrad O.
Primary Class:
Other Classes:
165/175, 29/890.047
International Classes:
B21D53/06; F28F9/02; F28F9/16; B21D53/02; F28F9/04
US Patent References:
2225856Heat exchanger
2568152Die for use with a punch
2861335Method of forming a hollow box in a metal wall
2862694Heat exchanger
2868513Heat exchanger
Foreign References:
GB273605A
CA540404A