Spray dispenser

1 . A hand held spray dispenser comprising:

a liquid chamber;

an air chamber; and

a mixing chamber;

wherein flow of a liquid in the liquid chamber and flow of air in the air chamber towards the mixing chamber is prevented by one or more valves of the spray dispenser;

wherein when the one or more valves are released, the liquid is forced under pressure from the liquid chamber to the mixing chamber via a liquid conduit and the air is forced under pressure from the air chamber to the mixing chamber via an air conduit to form an air-liquid mixture;

wherein the air-liquid mixture in the mixing chamber is forced through an exit orifice of the spray dispenser as a spray, wherein the spray dispenser has a single collar sitting around the spray dispenser in a plane orthogonal to a long axis of the spray dispenser that is configured to be rotated about the long axis of the spray dispenser with a unidirectional twist to energise one or more springs in the spray dispenser;

wherein energy from the one or more springs is released to generate sufficient air pressure and air flow and sufficient liquid flow for a spray to be formed from the air-liquid mixture as it leaves the exit orifice;

wherein rotation of the collar forces a cam follower of the spray dispenser to progress about a helical cam ramp in the spray dispenser causing axial movement of an internal chassis in the spray dispenser;

wherein axial movement of the internal chassis is configured to draw air into the air chamber and simultaneously energize a spring of the one of more springs to pressurise the air in the air chamber and the liquid in the liquid chamber;

wherein the air from the air chamber is not used to pressurise the liquid; and

wherein the air chamber comprises an inlet valve, wherein the inlet valve is configured to allow air to enter the air chamber whilst the air chamber is expanded.

2 . The spray dispenser according to claim 1 , wherein the air is pressurised at 0.3 bar to 3 bar prior to being forced from the air chamber.

3 . The spray dispenser according to claim 1 , wherein the spray dispenser is cylindrical in form.

4 . The spray dispenser according to claim 1 , wherein the liquid chamber is part of a refill unit, wherein the refill unit has a liquid chamber and a neck, the neck being reversibly attached to an internal cylindrical receiver by a screw thread.

5 . The spray dispenser according to claim 1 , wherein the collar does not need to be rotated back to its original position and where the spray dispenser is configured to reset itself ready for further activation during actuation.

6 . The spray dispenser according to claim 1 , wherein the air from the air chamber is introduced into the liquid from the liquid chamber adjacent to an inlet orifice of the mixing chamber.

7 . The spray dispenser according to claim 6 , wherein the inlet orifice and an outlet orifice of the mixing chamber are radially offset.

8 . A method of topical application of a cosmetic composition comprising using the spray dispenser according to claim 1 .