Insulated double-walled exhaust system component and method of making the same
Assignee3M Innovative Properties Company
InventorRichard P. Merry
Life of this patent
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Abstract
A double-walled exhaust system component having glass bubbles disposed between inner and outer pipes and method of making the same. The glass bubbles have a size distribution wherein, on a bulk volume basis, at least 90 percent of the glass bubbles have a size of less than 150 micrometers.
Claims20
An insulated double-walled exhaust system component comprising an inner pipe, an outer pipe surrounding the inner pipe, first and second annular seals connecting the inner and outer pipes and together with the inner and outer pipes defining an enclosed cavity, and glass bubbles substantially filling the enclosed cavity, the glass bubbles having a size distribution wherein, on a bulk volume basis, at least 90 percent of the glass bubbles have a size of less than 90 micrometers.
A method of making an insulated double-walled exhaust system component, the method comprising:
- providing an inner pipe;
- at least partially confining the inner pipe within an outer pipe;
- connecting the inner and outer pipes to form a fillable cavity having at least one opening;
- substantially filling the fillable cavity with glass bubbles having a size distribution wherein, on a bulk volume basis, at least 90 percent of the glass bubbles have a size of less than 90 micrometers;
- and
- sealing said at least one opening and enclosing the glass bubbles.
Dependencies are inferred from the claim text.