Dispensing – With discharge assistant – Fluid pressure
Patent
1987-06-25
1989-07-25
Shaver, Kevin P.
Dispensing
With discharge assistant
Fluid pressure
141 20, 22240216, 22240224, 22240225, 239337, B65D 8314
Patent
active
048505170
DESCRIPTION:
BRIEF SUMMARY
Currently known spray cans for spraying a liquid comprise a container for said liquid with a pressurized head space situated above the liquid, and a spray head closing said container and having a spray nozzle which is connected, by means of a dispensing valve, with a tube extending downwards to the vicinity of the bottom.
In the liquid a driving substance or propellant which is, at the normal pressure, a vapor, e.g., freon, is dissolved, and its vapor pressurizes the head space so that, upon opening the dispensing valve, the liquid is driven through the spray nozzle. The amount of driving substance should be sufficient for allowing the complete liquid contents to be sprayed in this manner. At each spraying, however, driving substance will be sprayed together with the liquid.
Because of the environmental objections existing against freon, containers of the above-mentioned kind have already been designed in which the pressure space can be filled by means of a pump with compressed air. Apart from the fact that, in this manner, the use of freon can be avoided, an additional advantage is obtained in that the container, after being emptied, can be filled again with the liquid to be sprayed.
In the case of a driving substance dissolved in the liquid and being sprayed together with the liquid, said liquid is divided into very small droplets, and the driving substance will vaporize immediately after spraying. These fine droplets allow a good distribution of a small amount of the liquid over the surface to be sprayed, without the liquid combining into larger drops whereby the surface to be sprayed would become too wet. When using a driving gas which is not dissolved in liquid form in said liquid, such as air, a so-called "dry spraying" is not truly obtainable especially where the liquid to be sprayed has a high viscosity and/or coherence. This is particularly difficult in the case of liquids such as hair varnish, sun-burn oil and other liquids to be sprayed on the body, and also in the case of lubricating oil, cleaning liquid for electrical contacts and the like, excessive spraying of which is objectionable or even harmful.
All this is a consequence of the fact that the liquid discharged from the nozzle remains more or less coherent or coalesces into larger drops, whereas, when using a vaporising driving substance, the coherence is broken by vaporisation of the driving substance, so that the small droplets remain in existence.
The difficulty mentioned above impedes wider use of spray means operating without a dissolved vaporising driving substance, and in particular using air as the propellant.
The invention provides a spray means of this kind which overcomes this objection.
The spray means according to the invention, which is intended for being arranged on a container for a liquid to be sprayed, in which container a head space for a pressurized driving gas such as compressed air is present above the liquid, the spray means comprising a spray head closing said container and having a spray nozzle which, by means of a dispensing valve, it connected with a dip tube extending downwards to the vicinity of the bottom of the container, so that upon opening the dispensing valve, the liquid is driven by the driving gas towards the spray nozzle in order to be sprayed therefrom, and is characterised in that the dip tube communicates with a mixing chamber which in turn communicates through the dispensing valve with the spray nozzle, and also communicates with the head space, in such a manner that upon opening the dispensing valve, a mixture of driving gas and liquid is driven out through said nozzle.
By turbulence in said mixing chamber the liquid is mixed with the driving gas, e.g. compressed air, the effect being that the desired spraying in the form of small droplets will occur.
The mixing chamber can be a venturi passage connected with the pressure chamber or head space, and the upper end of the dip tube communicating with the narrow portion of said venturi passage.
Preferably the mixing chamber comprises a more or less con
REFERENCES:
patent: 2518259 (1950-08-01), Stevenson
patent: 2746796 (1956-05-01), St. Germain
patent: 3372845 (1968-03-01), Frangos
patent: 3544258 (1970-12-01), Presant et al.
patent: 3644210 (1972-02-01), Crotty et al.
patent: 3704814 (1972-12-01), Ruscitti
patent: 3786963 (1974-01-01), Metzler, III
patent: 3851799 (1974-12-01), Paoletti
patent: 3955720 (1976-05-01), Malone
patent: 4247025 (1981-01-01), Gailitis
patent: 4396152 (1983-08-01), Abplanalp
patent: 4431119 (1984-02-01), Stoody
Airspray International B.V.
Shaver Kevin P.
LandOfFree
Pressurized spray dispenser having valved mixing chamber does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressurized spray dispenser having valved mixing chamber, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressurized spray dispenser having valved mixing chamber will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2351566