Fluid dispenser

A fluid dispenser comprising:

• a fluid reservoir of variable working volume, in which the reservoir fluid is protected from the air, a wall of the reservoir is an actuator wall that is axially movable down and up between a rest position and a depressed position, the movement of the wall causing the pressure in the reservoir to vary, the wall being situated at an end of the dispenser;
• and
• a dispenser orifice via which the fluid is dispensed, the orifice being provided with an outlet valve;
• the actuator wall is in direct contact with the fluid in the reservoir;
• and
• the reservoir forms a slide cylinder in which there is engaged a follower piston that is configured to slide in a leaktight manner in the cylinder, wherein the actuator wall and the follower piston move along a common axis X, and the follower piston remains static with respect to the cylinder during dispensing and moves with respect to the cylinder when the pressure on the actuator wall is released,
• including a bottom and a top when it is positioned upright, the actuator wall (25) being situated at a bottom wall of the dispenser, with the bottom wall of the dispenser bearing, in its rest position and in its depressed position, against the actuator wall.

A fluid dispenser comprising:

• a fluid reservoir of variable working volume, in which the reservoir fluid is protected from the air, a wall of the reservoir is an actuator wall that is axially movable down and up between a rest position and a depressed position, the movement of the wall causing the pressure in the reservoir to vary, the wall being situated at an end of the dispenser;
• and
• a dispenser orifice via which the fluid is dispensed, the orifice being provided with an outlet valve;
• the actuator wall is in direct contact with the fluid in the reservoir;
• and
• the reservoir forms a slide cylinder in which there is engaged a follower piston that is configured to slide in a leaktight manner in the cylinder, wherein the actuator wall and the follower piston move along a common axis X, and the follower piston remains static with respect to the cylinder during dispensing and moves with respect to the cylinder when the pressure on the actuator wall is released,
• including a one-piece body that internally defines the fluid reservoir, the body being closed by a bottom wall that forms the actuator wall.

A fluid dispenser comprising:

• a fluid reservoir configured to have a variable working volume so as to protect fluid in the reservoir from air, a wall of the reservoir being an actuator wall movable between a rest position and a depressed position, the movement of the actuator wall causing pressure in the reservoir to vary;
• and
• a dispenser orifice through which the fluid is dispensed, the orifice comprising an outlet valve;
• and
• a follower piston;
• the actuator wall is in direct contact with the fluid in the reservoir;
• and
• the reservoir defines a slide cylinder that engages the follower piston configured to slide in the slide cylinder in a leaktight manner from a first rest position defining a first volume of the reservoir to a second rest position defining a second volume of the reservoir, the second volume of reservoir volume smaller than the first volume of the reservoir, wherein the actuator wall and the follower piston move along a common axis X, and the follower piston remains static with respect to the slide cylinder during dispensing and moves with respect to the slide cylinder when the pressure on the actuator wall is released,
• wherein the follower piston comprises a connection duct that puts the reservoir in communication with the dispenser orifice.