Ink coupling for inkjet printer with cartridge
View Patent ↗An ink coupling for connecting an inkjet printer and a replaceable cartridge configured to not drip ink upon detachment. The coupling has a cartridge valve on the cartridge side of the coupling and a printer conduit on the printer side of the coupling. The cartridge valve and the printer conduit having complementary formations configured to form a coupling seal when brought into engagement. The cartridge valve is biased closed and configured to open when brought into engagement with the printer conduit. Upon disengagement, the coupling seal breaks after the cartridge valve closes, and an ink meniscus forms and recedes from the complementary formations as they separate, the cartridge valve having external surfaces configured so that the meniscus travels across the external surfaces and only pins itself to the printer conduit surfaces. The invention keeps residual ink off the exterior of the cartridge valve by careful design of the external surfaces with respect to known receding contact angle of the ink meniscus. As the coupling seal breaks and the meniscus forms, the ink properties and hydrophilicity of the respective valve materials will determine where the meniscus stops moving and eventually pins itself.
1. An ink coupling for establishing fluid communication between an inkjet printer and a replaceable cartridge for installation in the printer, the coupling comprising:
a cartridge valve on the cartridge side of the ink coupling; and,
a printer conduit on the printer side of the coupling, the cartridge valve and the printer conduit configured to form a coupling seal when brought into engagement; wherein,
the cartridge valve has an elastomeric sleeve with a sealing collar and a valve member, the valve member is fixed relative to the sealing collar which is biased into sealing engagement with the valve member to close the cartridge valve, and the printer conduit is sized to engage the sealing collar and move the sealing collar out of sealing engagement with the valve member by compressing the elastomeric sleeve while the valve member moves into the printer conduit interior in order to open the cartridge valve; such that,
during disengagement of the cartridge valve and the printer conduit, an ink meniscus forms and recedes from the valve member while pinning to the printer conduit.
2. An ink coupling according to claim 1 wherein at least one of the external surfaces of the cartridge valve has less hydrophilicity than at least one of the external surfaces on the printer conduit.
3. An ink coupling according to claim 1 wherein the cartridge engages from the printer by moving vertically downwards and disengages by moving vertically upwards.
4. An ink coupling according to claim 1 wherein, upon engagement, the coupling seal forms before the cartridge valve opens.
5. An ink coupling according to claim 1 wherein the conduit opening seals against the sealing collar before opening the cartridge valve.
6. An ink coupling according to claim 5 wherein the elastomeric sleeve and the sealing collar are integrally formed.
7. An ink coupling according to claim 6 wherein elastomeric sleeve and sealing collar are silicone.
8. An ink coupling according to claim 1 wherein the valve member is formed from polyethylene terephthalate (PET).
9. An ink coupling according to claim 1 wherein the conduit opening is formed from polyethylene terephthalate (PET).
10. An ink coupling according to claim 1 wherein the cartridge has a pagewidth printhead and the printer has an ink reservoir for supplying the printhead via the ink coupling.