Fluid supply assembly

1. A fluid supply assembly comprising:

a printhead assembly;

a carriage comprising a quick-release, hand-operable attachment mechanism to removably attach the printhead assembly to the carriage; and,

a fluid conduit interconnect directly and rigidly attached to the printhead assembly by a tool-operable fastener, the fluid conduit interconnect to connect to a fluid conduit to communicate printing fluid from an off-axis printing fluid supply to the printhead assembly.

2. A fluid supply assembly as in claim 1 , wherein the printhead assembly comprises a fastening element to receive the tool-operable fastener.

3. A fluid supply assembly as in claim 2 , wherein the fastening element comprises a threaded element selected from the group consisting of a tapped hole, a threaded bushing, a captive nut, an externally threaded insert, a helical insert, and a mold-in insert.

4. A fluid supply assembly as in claim 2 , wherein the fluid conduit interconnect comprises a through hole to enable the tool-operable fastener to pass through the fluid conduit interconnect to engage the fastening element of the printhead assembly.

5. A fluid supply assembly as in claim 1 , wherein the hand-operable attachment mechanism is to attach the printhead assembly to the carriage or detach the printhead assembly from the carriage in a single user action.

6. A fluid supply assembly as in claim 1 , wherein the tool-operable fastener comprises a threaded fastener.

7. A fluid supply assembly as in claim 1 , wherein the fluid conduit comprises flexible ribbon tubing having multiple fluid paths for interconnecting multiple off-axis fluid supplies through the fluid conduit interconnect to the printhead assembly.

8. A fluid supply assembly as in claim 1 , wherein the printhead assembly comprises engagement elements to attach to the hand-operable attachment mechanism.

9. A fluid supply assembly as in claim 8 , wherein the hand-operable attachment mechanism comprises:

a rotatable latch spindle having latch openings to receive the engagement elements of the printhead assembly; and,

a hand-operable lever, wherein the single user action comprises movement of the hand-operable lever to rotate the rotatable latch spindle to cause the latch openings to receive the engagement elements of the printhead assembly.

10. A fluid supply assembly as in claim 9 , wherein the engagement elements comprise protrusions emanating from the printhead assembly and oriented to enter the latch openings upon rotation of the rotatable latch spindle.

11. A fluid supply assembly as in claim 1 , wherein the printhead assembly comprises a printing fluid ejector, and wherein the fluid conduit interconnect is rigidly attached directly to the printhead assembly by the tool-operable fastener.

12. A fluid supply assembly as in claim 1 , wherein the carriage was initially designed for use with an on-axis fluid supply.

13. A fluid supply assembly as in claim 1 , wherein the carriage is a stationary carriage, and the printhead assembly comprises printing fluid ejectors that extend across a width of a print medium.

14. A printing system comprising:

an off-axis printing fluid supply;

a printhead assembly;

a carriage comprising a hand-operable attachment mechanism moveable between a locked and unlocked position, the locked position to secure the printhead assembly to the carriage, and the unlocked position to release the printhead assembly from the carriage; and,

a fluid conduit interconnect to provide printing fluid from the off-axis printing fluid supply to the printhead assembly through a fluid conduit, the fluid conduit interconnect directly and rigidly attached to the printhead assembly by a threaded fastener.

15. A printing system as in claim 14 , wherein the printhead assembly comprises:

an engagement mechanism to engage a latch opening in the attachment mechanism upon user actuation of the attachment mechanism; and,

a fastening element to receive the threaded fastener.

16. A printing system as in claim 14 , wherein the printhead assembly and fluid conduit interconnect comprise a needle-septum fluid transfer mechanism to enable transfer of printing fluid when the attachment mechanism is in the locked position.

17. A printing system as in claim 14 , wherein the printhead assembly comprises a printing fluid ejector, and wherein the fluid conduit interconnect is rigidly attached directly to the printhead assembly by the threaded fastener.

18. A method comprising:

providing a printhead assembly that is removably attachable to a printing system carriage by a hand-operable lever of an attachment mechanism, and a fluid conduit interconnect to communicate printing fluid from an off-axis printing fluid supply through a fluid conduit to the printhead assembly;

wherein the fluid conduit interconnect is directly and rigidly attached to the printhead assembly by a tool-operable, threaded fastener.

19. The method of claim 18 , further comprising:

providing an interface bracket between the printhead assembly and the fluid conduit interconnect to which the printhead assembly and fluid conduit interconnect are both rigidly attached by tool-operable, threaded fasteners.

20. The method of claim 18 , further comprising using the printhead assembly in a printing system carriage initially designed for use with an on-axis fluid supply.