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Patent
D271238
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Priority
Aug 13 1981
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Filed
Aug 13 1981
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Issued
Nov 01 1983
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Expiry
Nov 01 1997
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Assg.orig
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Entity
unknown
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2
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1
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n/a
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The ornamental design for a passive heat exchanger, as shown and described.
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FIG. 1 is a perspective view of a heat exchanger showing my new design; and
FIG. 2 is a rear view thereof.
Valencia, Benjamin L.
| Patent |
Priority |
Assignee |
Title |
| D264501, |
Oct 22 1979 |
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Heat retrieval unit for installation into a flue duct |
| Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
| Date |
Maintenance Fee Events |
n/a
| Date |
Maintenance Schedule |
n/a