US3752368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Airless liquid spraying device
Assignee: Individual
•
Filing: 1971-10-12
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Granted: 1973-08-14
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Expires: 1991-10-12
Abstract
Abstract A liquid spraying device employs compressed gas to urge a piston to slide in a tank and pressurize the liquid contained therein. The liquid is forced through a trigger operated liquid release valve and flows through a tip for mechanical atomization. Compressed gas is admitted into the tank through a pressure control valve which opens momentarily when a connected pushbutton is depressed and closes automatically in response to build up of pressure in a back pressure area. A commercially availiable cartridge is the preferred source of compressed gas and is supported by a holder part of the device.
Inventors
- 👤 H Robertson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:46
CPC Classifications
B; B05; B05B; B05B9/00; B05B9/03; B05B9/04; B05B9/08; B05B9/0805; B05B9/0833; B05B9/0838
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
214 words
A gas pressure powered device for dispensing liquid, which comprises: a tank having a first port and a second port; a piston slidable in the tank and partitioning the tank into a first reservoir and a second reservoir, the first reservoir for storing liquid and being in liquid flow communication with the first port, the second reservoir for storing gas and being in gas flow communication with the second port; first means having an operating cycle for admitting a pulse of pressurized gas into the second reservoir, the first means including a gas control valve in gas flow communication with the second port for admitting the pulse of gas when opened and cooperating with the second reservoir when closed to from a gas-tight closed chamber for containing the admitted gas, the contained gas urging the piston to slide in the tank, the gas control valve including a member movable to start the operating cycle by opening the valve and having a surface against which the admitted gas develops a force to move the member to close the valve thereby terminating the operating cycle; second means including a liquid control valve in liquid flow communication with the first port for spraying liquid driven out of the first reservoir when the liquid control valve is opened.
Claim 2
Dependent Claim
214 words
A gas pressure powered device for dispensing liquid, which comprises: a tank having a first port and a second port; a piston slidable in the tank and partitioning the tank into a first reservoir and a second reservoir, the first reservoir for storing liquid and being in liquid flow communication with the first port, the second reservoir for storing gas and being in gas flow communication with the second port; first means having an operating cycle for admitting a pulse of pressurized gas into the second reservoir, the first means including a gas control valve in gas flow communication with the second port for admitting the pulse of gas when opened and cooperating with the second reservoir when closed to from a gas-tight closed chamber for containing the admitted gas, the contained gas urging the piston to slide in the tank, the gas control valve including a member movable to start the operating cycle by opening the valve and having a surface against which the admitted gas develops a force to move the member to close the valve thereby terminating the operating cycle; second means including a liquid control valve in liquid flow communication with the first port for spraying liquid driven out of the first reservoir when the liquid control valve is opened.
Claim 3
Dependent Claim
28 words
A device according to claim 1 including a pressure release valve openable to release the contained gas from the closed chamber while the gas control valve is closed.
Claim 4
Dependent Claim
77 words
A device according to claim 1 wherein the first means comprises a base connected to the tank and supporting the gas control valve, the device further comprising a holder connected to the base for holding a cartridge of compressed gas, a gas flow channel in the base for directing gas escaping from the cartridge into the lower reservoir while the control valve is open; and means for puncturing the cartridge to permit the gas to exit therefrom.
Claim 5
Dependent Claim
72 words
A device according to claim 3 wherein the volume of the closed chamber increases as the liquid is sprayed and the piston slides in the tank; and including means for limiting the minimum volume of the closed chamber such that the ratio of the minimum to the maximum volume of the closed chamber is sufficient to assure that the pressure of the gas admitted into the chamber remains substantially above atmospheric pressure.
Claim 6
Dependent Claim
17 words
A device according to claim 4 including means for assuring a minimum volume of the second reservoir.
Claim 7
Dependent Claim
28 words
A device according to claim 1 wherein the second means includes a spray tip for atomizing the liquid flowing through it when the liquid control valve is opened.
Claim 8
Dependent Claim
20 words
A device according to claim 6 wherein the spray tip has a V-shaped opening subtending an angle of about 60*.
Claim 9
Dependent Claim
36 words
A device according to claim 1 including sealing means around the periphery of the piston for sealing the piston to the tank to separate the gas in the second reservoir from liquid in the first reservoir.
Claim 10
Dependent Claim
43 words
A device according to claim 8 including a flat bottom removable tank cap having the first port therethrough and wherein the inside periphery of the tank is uniform along its length to permit the piston to slide into abutment with the flat bottom.
Claim 11
Dependent Claim
97 words
A device according to claim 1 wherein the gas control valve comprises a vAlve housing having a bore therein, an inlet port for admitting gas into the bore, an outlet port for admitting into the second reservoir gas flowing through the bore, and a return port communicating with the outlet port to readmit the gas into the bore; and wherein the movable member is a plunger piston that in response to manually applied pressure slides in the bore to open the valve and that defines said surface, the readmitted gas developing the thrust to close the valve.
Claim 12
Dependent Claim
108 words
A device according to claim 1 and including a base connected to the tank and supporting the gas control valve, a first flow channel in the base for directing gas flowing out of the gas control valve and into the lower reservoir; a second flow channel in the base for directing gas flowing into the gas control valve; a pressure release valve openable to release the contained gas from the closed chamber while the gas control valve is closed; and a valve openable to release gas from the second flow channel while the gas control valve is closed and thereby not affecting the pressure in the closed chamber.
Claim 13
Dependent Claim
143 words
A device according to claim 1 wherein the gas control valve comprises a valve housing having a bore therein through which said movable member moves, an inlet port in the housing transverse to the bore for admitting gas into the bore, an outlet port in the housing transverse to the bore providing for gas to flow out of the bore during the operating cycle, and a return port communicating with the outlet port to readmit the gas into the bore; and wherein the movable member is an elongated plunger piston slidable in the bore to open and close the valve so as to admit the pulse of gas into the second reservoir, the plunger piston defining said surface at one of its ends facing the return port and the readmitted gas developing the thrust to close the valve and terminate the operating cycle.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |