Additive dispensing device and a thermally activated additive dispensing filter having the additive dispensing device

1. 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.

2. The thermally activated additive dispensing filter as in claim 1 , wherein the metering valve device further comprises a slidable piston member separating the dispensing chamber into a first chamber and a second chamber, the first chamber containing the thermal expanding member.

3. The thermally activated additive dispensing filter as in claim 2 , further comprising a biasing member configured to provide a biasing force to the thermal expanding member, the biasing force urging the thermal expanding member towards the contracted position.

4. The thermally activated additive dispensing filter as in claim 2 , wherein the thermally expanding member is configured to provide a force to the slidable piston member as the thermal expanding member moves from the contracted position toward the expanded position, the force decreasing the volume of the second chamber.

5. The thermally activated additive dispensing filter as in claim 2 , wherein a first wall portion of the second chamber includes the first one-way valve and a second wall portion of the second chamber includes the second one-way valve, the first wall portion being disposed between the reservoir and the second chamber, the second wall portion being disposed between the second chamber and the flow path inside the housing.

6. The thermally activated additive dispensing filter as in claim 5 , wherein the first one-way valve includes a plug member being configured to move between a closed position and an open position, a first biasing member being configured to move the plug member from the open position to the closed position with the plug member blocking an orifice in the first wall portion.

7. The thermally activated additive dispensing filter as in claim 5 , wherein the second one-way valve includes a detent member being configured to move between a closed position and an open position, a second biasing member being configured to move the detent member from the open position to the closed position with the detent member blocking a port in the second wall portion.

8. The thermally activated additive dispensing filter as in claim 2 , wherein a piston ring is sandwiched between the slidable piston member and the metering valve device.

9. The thermally activated additive dispensing filter as in claim 1 , wherein the collapsible membrane is located within a container that is in fluid communication with the flow path such that the collapsible membrane collapses as additive is drawn from the interior cavity.

10. The thermally activated additive dispensing filter as in claim 1 , wherein the filtration media defines an interior area with the flow path passing through the interior area, the additive dispensing device being configured to dispense the additive into the fluid passing through the interior area and directly to the outlet opening without passing through the filtration media.

11. The thermally activated additive dispensing filter as in claim 10 , wherein one end of the filtration media is attached to the housing such that the interior area of the filtration media is in open communication with the outlet opening of the housing, the other end of the filtration media being sealingly attached to the additive dispensing device such that the interior area is in communication with the metering valve device.

12. The thermally activated additive dispensing filter as in claim 1 , wherein the metering valve device is located within the reservoir.

13. The thermally activated additive dispensing filter as in claim 1 , wherein the thermal expanding member is formed from one of a wax material and a bimetallic material.

14. The thermally activated additive dispensing filter as in claim 1 , wherein the second one-way valve includes a detent member being configured to move between a closed position and an open position, a second biasing member being configured to move the detent member from the open position to the closed position with the detent member blocking a port in the second wall portion.

15. An additive dispensing device, comprising:

a housing;

a reservoir defined by an interior cavity of a collapsible membrane located within the housing, the reservoir being configured to contain a supply of an additive, the collapsible membrane being sealingly attached to a first one-way valve such that the interior cavity is in fluid communication with the first one-way valve, 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 a 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 interior cavity of the reservoir into the dispensing chamber through the first one-way valve, the thermal expanding member increasing 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;

wherein the metering valve device has a slidable piston member separating the dispensing chamber into a first chamber and a second chamber, the first chamber containing the thermal expanding member; and

wherein the collapsible membrane collapses within the housing as the additive is drawn out of the reservoir.

16. The additive dispensing device as in claim 15 , further comprising a biasing member configured to provide a biasing force to the thermal expanding member, the biasing force urging the thermal expanding member toward the contracted position.

17. The additive dispensing device as in claim 15 , wherein the thermally expanding member is configured to provide a force to the slidable piston member as the thermal expanding member moves from the contracted position toward the expanded position, the force decreasing the volume of the second chamber and wherein the housing has a plurality of openings that allow for fluid to be received in the housing as the collapsible membrane collapses.

18. A method of dispensing an additive into liquid passing through a filter media, comprising:

drawing a first amount of additive into a dispensing chamber through a first one way valve by contracting a thermally expanding member, from an expanded position to a contracted position, wherein the first one way valve is in fluid communication with an interior of a collapsible membrane that defines a reservoir for holding the additive; and

dispensing the first amount of additive from the dispensing chamber through a second one way valve by expanding the thermally expanding member from the contracted position to the expanded position by exposing the thermally expanding member to a fluid having a temperature higher than a temperature that causes the thermally expanding member to be in a contracted position; and

contacting the liquid passing through a filter media with the additive.

19. The method as in claim 18 , wherein the collapsible membrane is located within a housing and the collapsible membrane collapses within the housing as the additive is drawn from the reservoir.