in i in ii:urn i t:m m i Iiiii inn urn mi l in 11 n:
US005497944A
United States Patent [19] [ii] Patent Number: 5,497,944
Weston et al. [45] Date of Patent: Mar. 12, 1996
[54] ATOMISING DEVICES AND METHODS
[75] Inventors: Terence E. Weston, Woodbridge;
Stephen T. Dunne, Shotley, both of
England
[73] Assignee: DMW (Technology) Limited, United Kingdom
[21] Appl. No.: 938,174
[22] PCT Filed: Mar. 21, 1991
[86] PCT No.: PCT/GB91/00433
§ 371 Date: Nov. 19,1992
§ 102(e) Date: Nov. 19,1992 [87] PCT Pub. No.: W091/14468
PCT Pub. Date: Oct. 3,1991
[30] Foreign Application Priority Data
Mar. 21, 1990 [GB] United Kingdom 9006340
Nov. 1, 1990 [GB] United Kingdom 9023767
[51] Int. CI.6 A61M 11/00; B05B 11/00
[52] U.S. CI 239/321; 222/321.1; 222/321.8;
222/383.1; 222/384
[58] Field of Search 239/321, 518,
239/524, 543, 544; 222/321, 383, 384, 340, 341, 49, 321.1, 321.6-321.9, 383.1,
321.2
[56] References Cited
U.S. PATENT DOCUMENTS
334,110 1/1886 Delaney .
460,458 9/1891 Bates .
(List continued on next page.)
FOREIGN PATENT DOCUMENTS
21853/48 9/1948 Australia.
2017366 11/1990 Canada.
0086144 8/1983 European Pat. Off. .
0105964 4/1984 European Pat. Off. .
0111875 6/1984 European Pat. Off. .
European Search Report for Application No. 94112017.2 dated Jan. 13, 1995 (3 pages).
Primary Examiner—Andres Kashnikow
Attorney, Agent, or Firm—Sterne, Kessler, Goldstein & Fox
[57] ABSTRACT
A metered dose inhaler for dispensing a fluid medicament as droplets of small mean particle size without the use of pressurized gas or liquefied propellants. A liquid drug is contained in a fluid reservoir, and metered quantities of the drug are successively presented into a reduced cross-section pressure chamber, with non-return valves controlling the flow of liquid through the device. The metered quantity of the drug is then subjected to a sudden and great increase in pressure by releasing a piston into the pressure chamber. The liquid drug is thereby ejected through an atomizing head, to reduce it to a fine atomized spray of small mean particle size, preferably less than approximately 12 micrometers.
76 Claims, 7 Drawing Sheets
