Refill unit having fluid storage actuators

Abstract

A refill unit is provided for refilling a fluid storage compartment of a printer. The refill unit has a body containing fluid, and a plurality of actuators defined in the body for actuating a constrictor of the storage compartment as the refill unit engages with the storage compartment and deactivating the constrictor as the refill unit disengages from the storage compartment. The constrictor constricts a flexible wall of the storage compartment.

1 . A refill unit for refilling a fluid storage compartment of a printer, the refill unit comprising:
 a body containing fluid; and   a plurality of actuators defined in the body for actuating a constrictor of the storage compartment as the refill unit engages with the storage compartment and deactivating the constrictor as the refill unit disengages from the storage compartment, the constrictor for constricting a flexible wall of the storage compartment.   
   
   
       2 . A refill unit according to  claim 1  wherein the actuators are positioned in the body such that they are at the corners of a regular sided geometric shape. 
   
   
       3 . A refill unit according to  claim 2  wherein the actuators are generally flat pegs extending from the body such that the plane of each peg crosses the corresponding diagonal of said shape at right angles. 
   
   
       4 . A refill unit according to  claim 3  wherein the pegs are slightly arcuate with their respective centres of curvature proximate the centre of said shape. 
   
   
       5 . A refill unit according to  claim 4  wherein each of the pegs have a buttress reinforcement extending along the corresponding diagonal and towards the centre of said shape. 
   
   
       6 . A refill unit according to  claim 1 , wherein:
 the storage compartment is negatively pressurized storage and supplies fluid to a printhead assembly via a normally open outlet valve; and   the refill unit has engagement formations for releasably engaging the storage compartment and an outlet valve actuator for closing the outlet valve as the refill unit engages the storage compartment.