A fluid delivery device for delivering a fluid comprising:
- a piston assembly, the piston assembly including:
- a receiver cup having a cup base wall and a cup sidewall connected to the cup base wall and extending therefrom to form a cup rim, thereby forming a receiver volume existing between the cup base wall, the cup sidewall, and the cup rim;
- a plunger housing adapted to sealably and slidably fit within the receiver cup, the plunger housing having a plunger base wall and a plunger wall connected to the plunger base wall and extending therefrom to form a plunger rim, thereby forming a plunger volume existing between the plunger base wall, the plunger wall, and the plunger rim;
- a collapsible reservoir disposed within the plunger volume for containing the fluid and having at least one reservoir wall defining and enclosing a reservoir volume, and at least one reservoir port extending through the reservoir wall for communicating the fluid with the reservoir volume;
- a spring inset within the receiver volume of the receiver cup disposed to engage the receiver cup and the plunger housing for resisting compression of the plunger housing within the receiver cup;
- an inlet and an outlet for communicating the fluid with the at least one reservoir port;
- a receiver cup port extending through the receiver cup for regulating a fluid piston pressure within the receiver cup and within the plunger housing that is exerted on the collapsible reservoir,
- a pneumatic aspirator connected to the receiver cup port for regulating the fluid piston pressure by selectively controlling a flow of air in or out of the receiver cup port,
- a fixed pivot mount connected to or forming part of the receiver cup at a base wall end for connecting with a fixed pivot of a baseplate;
- a translatable pivot mount connected to or forming part of the plunger housing at a plunger base wall end or connecting with a translatable pivot;
- wherein, the fixed pivot mount is connected with the fixed pivot, the translatable pivot mount is connected with the translatable pivot, the translatable pivot is caused to travel from a first radial distance from the fixed pivot to a radial endpoint having a second radial distance, the second radial distance being less in distance from the fixed pivot than the first radial distance, thereby causing the plunger housing to slide further in the receiver volume and increase the fluid piston pressure;
- the pneumatic aspirator is disposed to stop the flow of air out of the receiver cup when the plunger housing slides into the receiver volume, the fluid piston pressure thereby exerted on the collapsible reservoir causes the collapsible reservoir to collapse, ejecting the fluid contained therein through the at least one reservoir port.