Patent ID: 8342370

Claim:
A one dose at a time canister for dispensing fluid, the canister being non-pressurised, said canister comprising an orifice from which fluid is dispensed as a result of two surfaces of the canister moving, from a non-dispensing starting position, towards one another under the control of a user; said surfaces comprising the respective opposite end region surfaces of a two-portion canister one of whose portions telescopes within the other; wherein the canister incorporates a mechanism which, once a first dose has been dispensed, acts to prevent any subsequent attempted movement of the said surfaces into or towards their non-dispensing starting position, and wherein the telescoped canister portions incorporate a one-way ratchet mechanism, said ratchet mechanism comprising a first rack and a second rack, each rack comprising a plurality of teeth, wherein upon assembly, a plurality of the teeth from each rack are interengaged and wherein when a dose is dispensed, the two racks ride over each other in relative axial movement causing further teeth from each of the racks to become interengaged, and wherein once the ratchet mechanism is assembled to form the canister, it resists any subsequent attempt at disassembly.