US3053461A - Pressure controlled spray device - Google Patents

Description

Sept. 11, 1962 Filed Nov. 12, 1959 I I] r 43 j, 522 I I 'E74 4 16 I ll! H" 2 Sheets-Sheet 1 P 11, 1962 B. D. INGLIS 3,053,461

PRESSURE CONTROLLED SPRAY DEVICE Filed Nov. 12, 1959 2 Sheets-Sheet 2 IN V EN TOR.

BRUCE 0. /IVGL/-5 United States Patent 3,053,461 PRESSURE CONTROLLED SPRAY DEVICE Bruce D. Inglis, Buffalo Road, East Aurora, N.Y. Filed Nov. 12, 1959, Ser. No. 852,458 4 Claims. (Cl. 239-411) This invention relates to liquid spraying devices and more particularly to an air actuated spray head for the spraying of liquids such as paint or the like.

One object of the invention is to provide an improved air-actuated spray head device as aforesaid which has a more positive and instantaneous on-oft action than known devices.

Another object of the invention is to provide an improved spray head as aforesaid which is particularly well adapted for automatic operation as for assemblyline painting operation and the like.

Another object of the invention is to provide an improved spray head as aforesaid in which a single air source serves to provide the spray head actuating force and the atomizing air.

Still another object of the invention is to provide an improved spray head as aforesaid which is of simple construction, operates with a fewer number of moving parts and can be made more compact and of smaller size than previously known devices.

Other objects and advantages of the invention will appear from the detailed description hereinbelow and the accompanying drawings wherein:

FIG. 1 is a longitudinal sectional view of the spray head of the invention with all parts shown in their oif or non-spraying position;

FIG. 2 corresponds to FIG. 1 but shows the device of the invention with its parts in on or spray position;

FIG. 3 is a transverse sectional view taken on line IIIIII of FIG. 1;

FIG. 4 is a transverse sectional view taken on line IV-IV of FIG. 1, and

FIG. 5 is a transverse sectional view taken on line VV of FIG 1.

Referring now to FIG. 1 of the drawing, the spray head of the invention includes a main body which is internally threaded at one end thereof to accommodate a back cap 12, and is externally threaded at its other end as indicated at 13 to accommodate a spray cap 14 thereon. The body portion-10 is longitudinally bored at its upper end as viewed in FIGS. 1, 2, to form a pressure chamber 16. A bore of relatively small diameter extends from chamber 16 and opens into a wide, shallow bore 22 which forms a spray chamber at the bottom end of the body 10; the bore 20 being counterbored as indicated to accommodate a packing 18 and packing nut 19. Additionally, the chamber 16 and 22 are connected by a series of small diameter bores 24 spaced around the bore 20. The body 10 is drilled and tapped radially at 27 to receive an air hose connection 30 in communication with chamber 16, and another radial bore 31 is provided to accommodate a paint supply hose connection 32, which connects through port 33 into chamber 22 adjacent the center thereof.

A nozzle plate 35 is threadedly fitted into the spray chamber 22, and is formed with a central, tapered orifice 36. The upper face of plate 35 is provided with an annular groove 37 adjacent its outer periphery and a Patented Sept. 11, 1962 series of holes 38 extend from the groove 37 through the plate 35. The end wall of chamber 22 and the upper face of the spray plate 35 are complimentarily grooved to accommodate an O-ring seal 39 as shown, to effectively seal oif the air flow stream from the liquid flow path. When the nozzle plate is in position as shown within the chamber 22, the tapered orifice is then disposed in communication with the paint liquid port 33; and the annular groove 37 and the holes 38 are in open communication with the bores 24, and hence with the air supply. Thus, the air and liquid will not mix until they converge at the spray opening 15 in the spray cap 14.

A needle valve 40 is slidably mounted in the bore 20; the packing 18 serving to fluid-seal the stem 40 in the body 10. The needle valve 40 carries a collar 41 and is threaded at its upper end above said collar. A sealing diaphragm assembly comprising a flexible fluid-sealing diaphragm 43 mounted between supporting washers 4445 is centrally apertured to slide over the end of the valve stem to rest on the collar 41 where it is firmly fixed by a nut 46 mounted on the threaded end of the valve stem. A Belleville disc spring 48, disposed with its normally convex side down to bias the valve assembly downwardly to closed position, is placed over the diaphragm assembly with its inner peripheral edge fitting into a suitably shouldered portion of the mounting washer 45 as shown. The diaphragm 43 is dimensioned so that when the assembly is positioned as shown, the periphery of the diaphragm is engaged between the body 10 and the cap- 12; while the periphery of the spring disc 48 bears into a shoulder formed in the cap 12.

Thus when the cap 12 is threaded into the body 10 with the valve and spring assembly in place, the outer periphery of the diaphragm 43 is clamped between the end of the cap 12 and the shoulder portion provided in the body 10, while the Belleville spring 48 is confined between the washer 45 and the cap 12, but is free to move to the small degree necessary for operative flexures of the spring, as will be explained hereinafter.

Selective determination of the size of the opening at the liquid orifice 36 is provided for by means of a set screw 52 which threads into an opening provided through the center of the cap 12. The set screw 52 may thus be turned down to limit the range of upward travel of the valve 40, to the extent which will produce the desired opening at the orifice 36. In operation, the spray device will be supplied with paint or other liquid to be sprayed at the desired pressure by any suitable means through the inlet 32. Spraying is then eifected by feeding air under pressure to the chamber 16 through the inlet 30. Air will then immediately flow from the chamber 16 through the bores 24, through the holes 38 in the spray plate 35, and then out of the opening 15 in the cap 14. However, spraying of the liquid will not immediately commence, until the air pressure in the chamber 16 builds up and becomes great enough to overcome the spring 48, and thus to oil can upwardly to withdraw the needle valve 40 from its closed position, as to the position shown in FIG. 2.

The air pressure at which spraying commences may of course be determined by selecting a spring such as will flex at the desired pressure. When the needle valve is unseated the paint or other liquid will be allowed to flow from the orifice 36 to mix with the air stream through orifice 15 and thus to be sprayed from the device. Whenever the air pressure is cut off, or falls below the actuating pressure of the Belleville spring, the spring will automatically snap back and close off the paint supply.

In operations where a spray of specific duration is desired, the spray head of the invention may be arranged for automatically timed shut-off by providing a calibrated bleed opening 53 through the diaphragm '43 and the washer 45; so that at the end of the prescribed spray period, the pressure differential between the chamber 16 and the bore 50 will be reduced below the flexpressure of the spring 48 and thus it will then automatically return the valve to off position.

For automatic venting the bore 50, a vent opening 54 is provided longitudinally through the center of the set screw 52. Thus when the valve is in the open position (FIG. 2) with the end of the valve stem abutting the end of set screw 52, it will close ofl the vent 54 and air entering the bore 50 through the bleed opening 53 will build up pressure to ultimately cause the valve to close automatically as described. When the valve returns to its closed position (FIG. 1) the vent 54 is automatically opened, and the bore 50 is thereby vented to the atmosphere, readying the device for the next on-otf cycle. The off time of the spray cycle may likewise be made automatic by calibrating the vent opening 54 so that the desired time interval elapses before the pressure differential between the chamber 16 and the bore 50 is again increased to the point where the spring 48 will again snap-flex to valve open position.

It is a particular feature that the construction of the spray head of my invention provides a device of extremely compact dimensions, and which is easily fabricated and employs only a few moving parts. The snap action of the actuating spring device provides a quick and positive on-Otf control, which gives a full spray throughout the entire spraying operation. This is particularly important in automatic operations where the controlling fluid pressures changes are slow and/or are of small magnitudes, such as would cause or allow conventionally used types of biasing means, i.e. coil springs or the like, to creep, and therefore give nonpositive control effects and permit imperfectly atomized paint to be sprayed from the device.

Thus it will be appreciated that by use of a snapaction type spring to control the movement of the dispensing valve stem, an improved operation is obtained; and that in lieu of the specific Belleville type spring shown and described hereinabove, any other suitable form of snap-action spring might be used; and that although only one form of the invention is shown and described in detail herein it is to be understood that various modifications can be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A spraying device comprising, a body member, a pressure chamber in said body member, a fluid pressure inlet communicating with said chamber, a sprayable material chamber in said body member, a valve member slidably mounted in said body member, said valve member having an elongate stern portion thereof extending into said pressure chamber and having its opposite end arranged to control the passage of sprayable material from said material chamber responsive to movement of said stem portion, a Belleville disc spring arranged to flex with snap action in response to pressure in said chamber and arranged in operating connection with said stem portion, said spring being disposed to bias said valve to snap toward its closed position, sealing means spanning said pressure chamber while permitting movement of said stem portion, passageways in said body member connecting with said pressure chamber and arranged to discharge adjacent the dispsensing opening of said device, pressure bleed-off means operable to allow pressure fluid to pass to the side of said sealing means away from said fluid pressure inlet, and pressure vent means in said body member connecting the portion of said presure chamber on the side of said sealing means away from said gas inlet with the atmosphere.

2. A spraying device comprising, a body member, a pressure chamber in said body member, a fluid pressure inlet communicating with said chamber, a sprayable material chamber in said body member, a valve member slidably mounted in said body member, said valve member having an elongate stem portion thereof extending into said pressure chamber and having its opposite end arranged to control the passage of sprayable material from said material chamber responsive to movement of said stem portion, a Belleville disc spring arranged to flex with snap action in response to pressure in said chamber and arranged in operating connection with said stem portion, said spring being disposed to bias said valve to snap toward its closed position, sealing means spanning said pressure chamber while permitting movement of said stem portion, passageways in said body member connecting with said pressure chamber and arranged to discharge adjacent the dispensing opening of said device, pressure bleedoff means operable to allow pressure fluid to pass to the side of said sealing means away from said fluid pressure gas inlet, and pressure vent means in said body member connecting the portion of said pressure chamber on the side of said sealing means away from said gas inlet with the atmosphere, said vent being arranged to be open when said valve is in closed position and closed off from the atmosphere when said valve is in open position.

3. A spring device comprising, a body member, a pressure chamber in said body member, a fluid pressure inlet communicating with said chamber, a sprayable material chamber in said body member, a valve member slidably mounted in said body member having an elongate stern portion thereof extending into said pressure chamber and having its opposite end arranged to control the passage of sprayable material from said material chamber responsive to movement of said stem portion, a Belleville disc spring arranged in snap action operating connection with said stem portion, said spring being disposed to bias said valve to snap toward its closed position, a flexible diaphragm spanning said pressure chamber and sealing the latter in pressure bearing relation against said spring disc, passageways in said body member connecting with said pressure chamber and arranged to discharge adjacent the dispensing opening of said device, pressure bleed-off means operable to allow pressure fluid to pass to the side of said sealing means away from said fluid pressure inlet, pressure vent means in said body member connecting the portion of said pressure chamber on the side of said sealing means away from said gas inlet with the atmosphere, said vent being arranged to be open when said valve is in closed position and closed off from the atmosphere when said valve is in open position.

4. A spring device comprising a body having a discharge orifice, means for supplying sprayable material to said discharge orifice, a valve member reciprocably mounted in said body for alternately opening and closing said orifice and so to control discharge of sprayable material from said body, said body having a pressure chamber and a flexible diaphragm. therewithin, an air pressure inlet conduit connected to said body and leading into said pressure chamber on one side of said diaphragm, said diaphragm being connected to said valve member to effect reciprocation thereof to open said discharge orifice when said pressure chamber is pressurized, a cup-shaped spring Washer fixed to said valve member and marginally seated on its concave side against said body to oppose opening movement of said valve member so that the valve member opens said orifice with a snap action only upon establishment of a predetermined pressure in said pressure chamber, said body having an atomizing chamber formed around said discharge orifice and being provided with passageway means connecting said pressure chamber to said atomizing chamber.

References Cited in the file of this patent UNITED STATES PATENTS Folberth July 15, 1919 Andler et a1. May 7, 1940 Palu-mbo May 17, 1949 Ehrling Aug. 20, 1957 Hair Mar. 3, 1959 Anderson Nov. 17, 1959

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