Patent ID: 7931817

Claim:
A thermally activated additive dispensing filter, comprising: a housing defining an inlet opening and an outlet opening, the housing further having a flow path between the inlet opening and the outlet opening, the fluid path being configured to pass a fluid therethrough; a filtration media located inside the housing and within the flow path such that a fluid in the flow path must pass through the filtration media; an additive dispensing device located inside the housing, the additive dispensing device having a reservoir configured to contain a supply of an additive, the reservoir being in fluid communication with a dispensing chamber of a metering valve device by a first one-way valve, the metering valve device being configured to dispense a portion of the additive from the dispensing chamber into the housing by a second one-way valve; and a thermal expanding member disposed in the dispensing chamber, the thermal expanding member being configured to expand and contract between an expanded position and a contracted position in response to temperature, the thermal expanding member decreasing a pressure in the dispensing chamber as the thermal expanding member moves from the expanded position towards the contracted position and additive is drawn from the reservoir into the dispensing chamber through the first one-way valve, and the thermal expanding member increases the pressure in the dispensing chamber as the thermal expanding member moves from the contracted position towards the expanded position and additive previously drawn from the reservoir chamber into the dispensing chamber is dispensed through the second one-way valve; and wherein the reservoir is defined by an interior cavity defined by a collapsible membrane that is configured to store the additive, the collapsible membrane being sealingly attached to the first one-way valve such that the interior cavity is in fluid communication with the first one-way valve and an exterior of the collapsible membrane is in open fluid communication with the flow path so that the collapsible membrane collapses as additive is drawn from the interior cavity through the first one-way valve.