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CH257661A
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Process for the production of a heat accumulator and heat a… |
Expired / Lapsed
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1947-01-23 |
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0 |
Details
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CH212604A
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Method for operating a warm air heating system and device f… |
Expired / Lapsed
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1939-10-13 |
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0 |
Details
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CH155866A
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Multi-stage pump with groups of several impellers mounted o… |
Expired / Lapsed
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1931-05-19 |
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0 |
Details
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