Spray gun with disposable liquid handling portion

• US 4,971,251 A
• Filed: 09/11/1989
• Issued: 11/20/1990
• Est. Priority Date: 11/28/1988
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Cheesebrow, Dennis M., LaPlante, Earl T., Dobrick, Robert P., Johnson, Dee L.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): TRAINOR, CHRISTOPHER
• Application Number:
  US07/405,454
• Time in Patent Office: 435 Days
• Field of Search: 239/309, 239/310, 239/311, 239/315, 239/316, 239/327, 239/328, 239/337, 239/340, 239/346, 239/369, 239/371, 239/390, 239/423, 239/271, 239/272, 222/107, 222/129, 222/136, 222/145, 222/541, 222/630, 222/637, 222/95, 206/219, 206/222, 383/38, 267/166.1
• US Class Current: 239/346
• CPC Class Codes: B05B 15/30 Dip tubes
• CPC Class Codes: B05B 7/2408 characterised by the container or its attachment means to the spray apparatus
• CPC Class Codes: B05B 7/2435 the carried liquid and the main stream of atomising fluid being brought together by parallel conduits placed one inside the other
• CPC Class Codes: B05B 7/2481 with a flexible container for liquid or other fluent material

Abstract

A liquid spray gun including (1) a reusable air gun portion including a manually operable valve for controlling air flow; and (2) a disposable container and spray nozzle assembly including a sheet of flexible material having portions attached together and to a central portion of a tube to form a chamber, a liquid in the chamber, and an aspirating nozzle connected to the tube and adapted to be releasably coupled to the air gun portion so that upon movement of air through the nozzle liquid in the chamber will be entrained in that air and sprayed from the nozzle. The assembly can include a coil comprising a strip disposed in a plurality of wraps about an axis and having a spring temper biasing the strip to an axially extended position to form a tube like structure, with an end portion of the coil positioned around an end portion of the tube within the bag so that during spraying the tube like structure will insure that most of the liquid can be dispensed from the chamber. The sheet of flexible material also includes edge segments that are not attached together to thereby form vents for communicating the chamber to the atmosphere.

Claims

1. A disposable container and spray nozzle assembly for spraying liquid onto a surface when the assembly is attached to a source of air under greater than atmospheric pressure, said assembly comprising:

a tube having a through opening, an outlet end portion, an inlet end portion, and a sealing portion between said inlet and outlet end portions;

at least one sheet of tough flexible material having portions attached together and to said sealing portion of said tube to form a bag like container defining an internal chamber with the inlet end portion of said tube within said chamber and the outlet end portion of said tube outside of said chamber, said at least one sheet having portions attached together along a line of temporary attachment to separate said chamber into first and second parts;

a liquid in said second part of said chamber;

tubing means in said chamber coupled to said inlet portion of said tube and adapted for contact with liquid;

a nozzle having a liquid inlet port connected to said outlet portion of said tube with said through opening in said tube communicating with said liquid inlet port, an air inlet port adapted to be coupled to the source of air under pressure, a spray tip portion having an outlet opening, a through opening communicating between said outlet opening and said liquid and air inlet ports, and means for forming a vacuum at the liquid inlet port upon movement of air into said air inlet port and out said outlet opening in said spray tip portion so that atmospheric pressure will bias liquid in said chamber into said liquid inlet port to be entrained in air passing through said through opening of said nozzle and out of said outlet opening, and

a vent in said first part for communicating said chamber with the atmosphere.

2. An assembly according to claim 1 wherein said vent is self-closing under the influence of negative pressure in said chamber.

3. An assembly according to claim 2 wherein said vent is remote from said tubing means.

4. An assembly according to claim 1 wherein said sheet includes edge segments that are not attached together, thereby presenting said vent.

5. An assembly according to claim 1 wherein said tubing means is initially located in said first part and is extendable into said second part upon separation of said line of temporary attachment.