US2079933A - Spray gun - Google Patents

Description

C. S. FISHER May 11, 1937.

SPRAY GUN Filed April 21, 1932 3 SheetsSheet 1 INVENTOR 6/4ar/e: J. fisher TTORNEYS 3 Sheets-Sheet 2 W a e 4% 4 a R w a m E 1 a w C. S. FISHER SPRAY GUN Filed April 21, 1932 May 11, 1937.

y 1937. c. s. FISHER 2,079,933

SPRAY GUN Filed April 21, 1932 5 Sheets-Sheet 3 II i E I E- a 1. INVENTOR TTORNEYS Patented May 11, 1937 PATENT OFFICE SPRAY GUN Charles S. Fisher, Detroit, Mlcln, assignor to Saylor-Beall Manufacturing Company, a corporation of Michigan Application April 21, 1932, Serial No. 606,558

2 Claims.

This invention relates to spraying devices and more especially to spray guns for applying paints,

. lacquers, enamels, varnishes, oils, insecticides and other liquids, semi-pastes or finely divided materials to desired objects.

The principal object of the invention is to provide an-all purpose spray gun that may be used as a pressure or syphon type gun or may be used in conjunction with a pressure feed material tank. m Another object is to provide a gun that may be .easily adapted for different purposes by making very simple changes and adjustments.

Other objects and advantages will become apparent from the following description and ap- 15 pended claims. 7 For the purpose of illustrating the genus of the invention, a typical concrete embodiment is shown in the accompanying drawings in which:

Fig. 1 is a vertical longitudinal section, pardo tially in elevation, through a device constructed in accordance with this invention, the parts of the device being shown in unoperated positions;

Fig. 2 is a top plan view of the device shown in Fig. 1;

Fig. 3 is an enlarged vertical section on line 3-3 of Fig. 1;

Fig. 4 is a horizontal section on line 4-4 of Fig. 1-;

Fig. 5 is a vertical section on line 5-5 of Fig. 4;

Fig. 6 is a fragmentary view similar to Fig. 1 with parts in operated position and engaging an adjustable stop means for such parts;

Fig. 7 is a vertical section of a solder bath and illustrating a step in the fabrication of the pressure cup illustrated in Fig. 1;

Fig. 8 is a side elevation, on an enlarged scale, of the material nozzle shown in section in Fig. 1;

Fig. 9 is a vertical longitudinal section, on an enlarged scale of the air nozzle shown in Fig. 1 and illustrating in dot-and-dash line the material nozzle shown in Fig. 8 as these parts are associated in an internal atomizing type of spray gun;

Fig. 10 is an enlarged front elevation of another form of air nozzle of the internal atomizing type.

Fig. 11 is a vertical longitudinal section taken on the line Il-ll of Fig. 10 and showing in dotand-dash line the material nozzle illustrated in Figs. 8 and 9;

Fig. 12 is a horizontal longitudinal section taken on the line l2-l2 of Fig. 11;

Fig. 13 is a view similar to Fig. 10 of another form of air nozzle of the internal atomizing type;

Fig. 14 is a vertical longitudinal section on line ld-ld of Fig. 13;

Fig. 15 is a vertical longitudinal section of an external atomizing type of material nozzle interchangeable with the nozzle of the internal atomizing type shown in Fig. 8;

Fig. 16 is an enlarged front elevation of an air nozzle adapted to be used with the material nozzle shown in Fig. 15;

Fig. 17 is a section taken on line l'l-lll of Fig. 16 and illustrating the position of the material nozzle shown in Fig. 15;

Fig. 18 is a section on line Iii-l8 of Fig. 17;

Fig. 19 is an enlarged front elevation of another form of external atomizing air nozzle adapted for use in connection with the material nozzle shown in Fig. 15;

Fig. 20 is a longitudinal vertical section of the air nozzle shown in Fig. 19 and illustrating in Referring to the drawings, and particularly to Figs. 1 to 6 inclusive, a spraying device is dis-- closed in the form of a spray gun, which maybe used as a pressure type gun, a syphon type gun, or may be used in connection with a pressure feed material tank. This gun comprises a body member l0 provided with air and material passages, designated II and I2, respectively. An intake union I3 is threaded into the rear portion of the body member l0 so as to communicate with the air passage H. The union I3 is adapted to have a flexible air line coupled thereto for supplying compressed air to the air passage l I. In this type of gun, air is continually passed through the body member Ill and the volume of air passed therethrough is controlled by the relative adjustment of material and air nozzles I 4 and I5 which are concentrically disposed relative to each other and connected to the forward end of the body member l I in a manner which will later be more fully described. A downwardly extending cylindrical flange member [6 is formed on the body member Ill and is internally threaded as indicated at H so that a pressure cup l8 may be secured thereto. The body member is provided with a downwardly extending passage 20 communicating between the material passage l2 and the interior of pressure cup l8. A material tube union 2i is threaded within the passage 20 and secures a material tube 22 to the body member ID. The body member is 4O nozzle l4 and in concentric relation with respect also provided with passages 23 and 24 which communicate between the air passage ii and the interior of the cup member, and between the exterior of the body member l0 and the interior, of the cup member II, respectively. The passages 23 and 24 are internally threaded to receive interchangeable plugs 25 and 26, plug 25 being provided with a vent passage therethrough and plug 26 being solid. Interchanging of these plugs converts the spraying device from a pressure type to a syphon type of gun.

Referring particularly to Figs. 4 and 5 the vented plug 25 is disclosed as being positioned in the passage 23, thus providing a vent between the air passage ii and the interior of cup so that air pressure may be exerted on the top of the material within the pressure cup l8, thus providing a pressure type of spraying gun. In this instance the solid plug 26 closes the vent passage 24 so that no vent is provided between the interior of the pressure cup l8 and the exterior of body 'member iii. If, however, these plugs are inter- "changed the vent, afiorded by means of the vented plug 25 disposed in the passage 24, is between the interior of the pressure cup l8 and the exterior of the body member ID. With the solid plug 26 closing the passage 23 no pressure will be exerted on the top of the liquid material within the pressure cup l6 from the air passage II. In the latter instance the gun is arranged as a syphon type spraying device.

The forward end of the material passage i2 is internally threaded to receive complementary threads 21 on the material nozzle i4. The forward end of the body member I6 is provided with a cylindrical flange member 28 which is internally threaded at 30 to receive complementary threads 3! on the nozzle member l5. Thus, 'means are provided for securing the latter in the desired adjusted position relative to the material to the material nozzle. A flange member 28'is also externally threaded to receive a sleeve mem ber 33 provided with a radially disposed flange 34 which cooperates with a flange 35 on nozzle member i5 for locking the nozzle member in ad- 'justed position relative to the material nozzle l4. 'The air passage I I communicates with a chamber 36 formed by the flanged member 28, which chamber communicates with the interior of the air nozzle l5. The interior surface of the nozzle 15 and the exterior surface of the nozzle i4 are in the form of converging cones so that the air passing between these nozzles will have an increased velocity as it is discharged through a circular opening 46 at the tip of the air nozzle l5. It is noted that the interior surface 38 merges smooth ly with the opening 40 in the tip of nozzle l5, no

shoulder being provided on the air nozzle at this point. Nozzle l5 may be adjusted relative to nozzle l4 so as-to completely shut off the flow of air between the nozzles, if desired.

A needle valve member 4i is provided in the passage i2 to control the flow of material through needle valve member 4i and the body member i0.

A bifurcated extension member 41 is integrally formed on the rear portion of the body member Iii to provides support means for the control mechanism for the needle valve member 4|. The end of the extension member 41 provides a grip means 46 which is downwardly directed relative to the body member and is disposed in rear of the pressure cup l6. A boss 56 is provided on the top margin of the extension member 41 and a passage is provided in this boss which extends in the direction of the passage I2 with its axis coincident with the axis of the needle valve member 4 I. The passage 5i is internally threaded to receive the needle valve adjustment screw 52. This screw is centrally bored as indicated at 53 to receive the needle valve spring 54. The needle valve member 4| is threaded at the rear end thereof to receive the needle'valve adjustment screw stop member 55 and a lock nut therefor designated 56. The

stop member 55 is machined slidably to fit the :1

bore 53 of the needle valve adjustment screw 52 and a shoulder 51 is provided on the forward end of stop member 55 to engage the forward end of the adjustment screw 52.

In the above arrangement the spring 54 norcrank pivoted to the extension member 41 by 3 means of a bearing pin'5l. One arm 62 of the trigger member is provided with a cam surface 63 and the other arm 64 is provided with a flnger piece 64. A pair of trigger cams 55 is also pivcited to the extension member 41 on the bearing pin 66 and one arm of each trigger cam is provided with a bearing surface 61 on one arm and a second cam surface 68 on the other arm. The trigger and trigger cams are so arranged that the cam surfaces 68 engage the lock nut 56 so that pressure on the flnger piece 64 causes rearward movement of the needle valve member 4|. The cooperating cam surfaces 63 and 61 are so arranged that, upon initiation of movement of the trigger finger piece 64, the arms of the trigger and trigger cams are essentially equal, however, as movement of the finger piece 64 continues, the arm 62 of the trigger lengthens and the cooperating arms of the trigger cams 65 shorten so that cams 68 move rearwardly at a progressively ini creasing rate relative to the rearward movement of the finger piece 64. Thus upon the initiation of the rearward movement of the finger piece 64 the maximum sensitivity of adjustment of the needle valve 4| is obtained. Upon continued rearward movement of the finger piece 64 the control of the needle valve member is less sensitive and the needle valve member is moved rearwardly at a faster rate. The maximum sensitivity of control of the needle valve is desirable at the initiation of the movement of the trigger for decorative or fine work such as lining or work close to the margin of a different color. It is also desirable to provide means for effecting a quick opening to the valve so that slugs of material in the nozzles of the gun maybe cleared out by a sudden blast of material therethrough. The control mechanism above described, satisfies both requirements. It is noted that in the present construction, which provides two trigger cams of, which carry the cams 61 and 68, disposed at a slightly smaller angle with respect to each other than the angle formed by the corresponding legs of the uppermost trigger cam. Since both trigger cams are rotated about the pivot 66 in a clockwise direction by the same cam surface 63, the lowermost trigger cam will exert the greater pressure on the lock nut 56 while the uppermost trigger cam will bear but lightly on the lock nut or even may be slightly spaced therefrom. As viewed in Fig. 2,'the trigger cam 65 adjacent the bottom of this figure, preferably exerts the greater pressure, since this will at all times tend to keep the lock nut 56 secured against the needle valve stop member 55. The rotation ofthe needle valve member 4| by the trigger cams 65 upon operation of the needle valve member will cause its tip 42 to grind into and out of the valve seat 43 thus keeping the tip 42 and seat 43 free from the material being dispensed and keeping the surfaces, valve tip and valve seat ground so as to make full contact to insure complete closure of the material passage I2. The double cam lever construction permits a lowered disposition of the handle and shielding of the major part of the moving element by the gun and pressure can. This .makes the cleaning of the gun easier. operating the needle valve it is to be noted that the resistance of the trigger is practically constant and that spring 54 is always compressedto the same extent at the limit of the rearward movement of valve 4| regardless of the position of adjustment screw 52. It is also noted that valve 4i may be disassembled from the gun by simply unscrewing adjustment screw 52 from boss 50 without any other disconnection of the valve from its control mechanism.

Referring particularly to Figs. 1, 3, and 4 it will be noted that the material nozzle I4 has a hexagonally cut color III integral therewith of a size such that it will fit closely the interior of the air nozzle I5 and at the same time permit free passage of air along the flats of this collar from the air passage II to the space between the material and air nozzles. It is also noted that immediately forward of the collar III the material nozzle I4 has diametrically opposed cuts II so that the material nozzle may be turned into the body member III to effect a seal between these members.

Referring particularly to Figs. 1 and 7, the construction of the pressure cup will be described. It has been the usual practice to construct these cups of aluminum with the threads rolled into the neck portion thereof and a bulge extending inwardly into the bottom of the cup. In order to withstand the internal pressure in the cup and outward bulging ofthe bottom portion resulted when slugs were caught in the nozzles of the gun. Internal reinforcements of the bottom bulge of the cup have been attempted but since air gets between these reinforcements and the cup bottom the effect is lost. Outside reinforcements also have been attempted but as this mars the appearance of the cup, this expedient has not been brought into extensive use. In rolling the threads into the neck portion of the head it is practically impossible to get the end of the neck portion of the cup square with the threads. In such a construction the end of the neck portion is usually rolled inwardly to get a smooth edge for the gasket interposed between the cup and the gun and it has sometimes been attempted to machine the ends, however, this causes a very large percentage of scrapped cups, since because of the thinness of the material, the cutting often projects through the end of the rolled portion. This also develops in a wide bearing portion at the end so that a large force must be employed to effect a seal between the cup and gun or to unscrew a cup from the gun portion.

In the present construction the pressure cup I8 is made of two parts, namely a collar member I3 and a heavy sheet copper container member I2 having an inwardly directed bulge portion at the bottom thereof and a cylindrical neck portion at the upper end. A collar member I3 is turned from solid material, such as brass, the collar havsecuring the collar I3 to the container member I2 I the collar is placed on the neck portion thereof and the upper margin of the neck is pressed outward slightly to position the collar relative to the container. The neck portion of the container with the collar thereon is then dipped in a solder bath 69 as indicated in Fig. 7 to effect a solder connection between the neck portion and the collar, and also to give the exterior surface of the threads 14 a babbitt surface or plating I6. The babbitt surface or plating I6 on the thread I4 offers the minimum of friction between the threads of the collar and of the gun proper, so as to afford ease of operation and freedom from sticking when the pressure cup and gun are assembled and disassembled. The gasket 18 is interposed between the ends of the pressure cup and the body portion of the member ID. A cup of the above construction will withstand an internal pressure of '75 pounds per square inch without causing an outward bulging of the bottom thereof. In the two piece construction of the pressure cup the container may be made of much thicker material than in the case of the one piece cups having threads rolled therein, so the two piece cups may be made to withstand any desired internal pressure without causing a deformation of the bottom thereof.

Referring particularly to Figs. 8 and 9 the internal atomizing type of nozzles are shown which are preferably machined from brass and chromium plated. These nozzles are the same as illustrated in Figs. 1 to 4 inclusive.

In Figs. 10 to 12 inclusive. internal atomizing nozzles are shown which are similar to those previously described except that a slot, 8i is provided in the tip of the air nozzle I5 instead of the circular opening 40 disclosed in the previous embodiment. Th s slot 8| flattens the spray delivered by the gun so that a thinner and more uniform application of the material to be dispensed may be made. It is noted that the interior surface 81 of the air nozzle l5 merges smoothly with the slot 8| and that no shoulder is provided at this point. It has been found that better atomization of the material to be dispensed is obtained when no shoulder is provided on the air nozzle adjacent the circular or slotted openings therein.

In the nozzles shownin Figs. 13 and 14, a slot 82 is provided in the tip of the air nozzle I! which is disposed at an angle with respect to the axes of the material and air nozzles and somewhat to the side of said axes. This inclination of the slot in the tip of the air nozzle is provided so that the gun is more readily adapted for application of material to horizontal surfaces disposed above or below an operator, such as ceilings and floors. In applying material to .surfaces such as ceilings, the nozzle would be adjusted to the position shown in Fig. 13 and in applying it to surfaces such as floors, this nozzle would be rotated to a position at an angle of 180 degrees from that shown in Fig. 13. It is to be noted that in this instance also, the interior surface 31 of the air nozzle l5 merges smoothly with the margins of the slot 82 so that no shoulder is provided adjacent the tip of the nozzle I 5.

In the nozzles disclosed in Figs. 9 to 14 inclusive, it is noted that in each instance the interior surface of the air nozzle and the exterior surface of the material nozzle comprise converging cones which increase the velocity of air as it passes between these nozzles. This effects very complete atomization of the material dispensed.

In Figs. 15 to 18 inclusive the external atomizing type of nozzles are disclosed. These nozzles are preferably machined from brass and nickel plated. These nozzles are .interchangeable with the internal atomizing type of nozzle previously described. The material nozzle 84 and air nozzle 85 in the present instance, however, are made blunter at the tip than in the case of the internal atomizing type of nozzle above described.

The exterior surface 88 of the material nozzle 84 and the interior surface 81 of the air nozzle 85 are inclined at a greater angle with respect to the axes of the nozzles than in the case of the internal atomizing type and comprise converging cones to increase the velocity of the air as it passes between the nozzles, as in the previous embodiments. The material nozzle 84 is provided with a cylindrical extension at the forward end which is adapted to project through a circular opening in .the tip of the air nozzle 85. The extension extends slightly beyond the opening, however, this member should not extend more than of an inch beyond the end of the air nozzle 85. The nozzle 85 is secured to the body member ill of the gun by means of a so as to receive air therefrom for flattening the spray.

In use, the internal atomizing nozzles are used for slow drying materials, such as paints and varnishes, in which instance, air pressure is required on the material in the pressure cup. When using the internal atomizing nozzles, the interchangeable plugs 28 and 28 are positioned as disclosed in Fig. 5. The external atomizing type of nozzles are used for fast drying materials. such as lacquers, synthetic enamels, etc. In using the external atomizing nozzles, no pressure is exerted on the material within the pres sure cup since the side stream of air cannot break up the spray fast enough. Instead, the spraying device is used as a syphon type sun, in which instance, the positions of the interchangeable plugs 25 and 26 are reversed with respect to the positions shown in Fig. 5, so that the passage 28 is closed and the vent passage 24 is opened from the cup interior to the atmosphere.

when the spraying device is employed in connection with a. pressure feed material tank, the tube 22 and pressure cup 18 are removed from the spraying gun. A flexible hose from the pressure tank may be connected to the passage 28 to apply the material to be dispensed. The interchangeable plugs 25 and 28 are arranged in the same manner as in the case of the syphon type gun and either the internal atomizing or the external atomizing type of nozzles may be employed, however, when using the external type, a regulator is employed in connection with the pressure feed material tank to lower the pressure at which the air is delivered thereto. I

It is noted that the tube 22 is provided with a bend so that it may extend to either the forward portion of the bottom of the pressure cup as disclosed in full lines, or adjacent the rear portion of the bottom of the pressure cup as disclosed in dotted lines, in Fig. 1. This is to permit withdrawal of practically all of the material within the pressure cup when the nozzles shown in Figs. 13 and 14 are employed. When applying material to a horizontal surface, such as a floor, the tube 22 is positioned as shown in full lines in Fig. 1, and when applying material to a horizontal surface, such as a ceiling, the tube is positioned as shown in dotted lines in this figure.

As many changes could be made in the above described arrangement, and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or showing shall be interpreted as illustrative and not in the'limiting sense.

What is claimed is: v

1. A spraying device comprising a body member provided with material and air passages therein, valve means for closing said material passage, means foroperating said valve to regulate the flow of'material through said material passage, a pressure cup removably secured to said body member, a conduit member secured to said body member and communicating between said material passage and the interior of said pressure cup, said body member being provided with other passages, onepassage communicating between said air passage and the interior of the pressure cup and another passage communicating between the exterior of said body member and the interior of the pressure cup; and means for closing either of said two last-named passages for selectively converting the spraying device from a syphon type to a pressure type of spraying device.

2. A spraying device comprising a body member provided with material and air passages 10 said pressure cup, said body member being provided with other passages, one passage communicating between said air passage and the interior of the pressure cup and another passage communicating between the exterior of said body member and the interior of the pressure cup, and interchangeable plugs for said two lasthamed passages, one of said plugs being solid and the other provided with an opening therethrough whereby said spraying device may be converted from a syphon type to a pressure type of spraying device by interchanging said plugs. 10

CHARLES S. FISHER.

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