Portable urethane spray gun
United States Patent 3920188

A portable urethane spray gun is disclosed. The apparatus includes a structure for controlling the discharge of the components of the urethane, thoroughly mixing the components of the urethane and purging the spray gun of one of the components by stopping the flow of the other of the components prior to stopping the flow of the purging component thereby providing for dispensing of urethane without the use of compressed air for atomization or purging.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
239/414, 239/416
International Classes:
B05B7/12; B05B15/02; (IPC1-7): B05B7/12; F23D13/38
Field of Search:
239/399,525,526,414,416,403 222
View Patent Images:
US Patent References:
3726634BURNER1973-04-10Thomson et al.
3595482SPRAY DEVICES1971-07-27Loveday
3409044Foam gun head1968-11-05Sobek et al.
3375978Spray gun with self-purging nozzle1968-04-02Rennie
3232540Spray gun for two-component paints, with separate concentrical nozzles1966-02-01Cassanmagnago
3144210Spray gun1964-08-11Levy

Primary Examiner:
King, Lloyd L.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows

1. A spray gun and nozzle combination comprising,

2. The combination recited in claim 1 wherein said inner nozzle member has a cylindrical outside surface,

3. In combination, a spray gun and a nozzle and a shutoff means,


1. Field of the Invention

The present invention generally relates to the spraying of urethane foam onto desired surfaces, into areas and wherever desired, which is portable in nature and provided with a unique arrangement of structure for providing a supply of urethane components, mixing and spraying the components, with the arrangement being such that the spraying device will be purged to eliminate hardening or solidification of the mixed components in the spraying device.

2. Description of the Prior Art

Devices for spraying two fluid component materials are known in which the components are mixed prior to discharge or subsequent to discharge. Prior U.S. Pat. No. 3,179,341, issued Apr. 20, 1965, is exemplary of such devices and this patent also discusses the development of the prior art in this field. Additional patents exemplary of spray guns are U.S. Pat. Nos: 3,232,540, issued Feb. 1, 1966, and 3,375,978, issued Apr. 2, 1968. Such devices have generally required the use of compressed air for thorough mixing and atomization of the two components or for purging the spraying device and, in some instances, employ a solvent for purging. While known devices have been used to some degree of success, considerable problems still exist in providing a portable urethane spraying system, heating the components under accurate control and spraying the mixed components with a spray gun and purging the spray gun after use.


The urethane spray system of this invention incorporates two conduits extending from each of the supply tanks which are each provided with a heater for maintaining the temperature of the components within desired limits and each conduit is also provided with a flow valve and the conduits are connected with a spray gun. The spray guns are provided with nozzles that are virtually self-cleaning and shutoff valves that require a minimum of maintenance.


An object of the invention is to provide a portable urethane system employing a spray gun that does not require any external air or any solvent purge to operate in a continuous manner with the spray gun including a nozzle structure that will thoroughly mix and dispense two components of the urethane in a manner to enable the mixed urethanes to be placed in voids for the purpose of insulation or floatation or discharged in an atomized spray pattern onto a surface.

Another object of the invention is to provide a urethane spray gun which is effective in operation, accurate in control, efficient in operation, easy to use and maintain and relatively inexpensive in manufacture and operation with the device being constructed so that portability thereof is maintained.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.


FIG. 1 is an isometric view of the gun according to the invention.

FIG. 2 is a transverse, sectional view, on an enlarged scale, taken substantially upon a plane passing along section line 2--2 of FIG. 1 illustrating further structural details of the gun.

FIG. 3 is a vertical sectional view taken substantially upon a plane passing along section line 3--3 of FIG. 2 illustrating the structural details of the spray gun.

FIG. 4 is an enlarged view of a part of the nozzle.

FIG. 5 is a front view of the inner nozzle part with the outer part removed, taken at line 5--5 of FIG. 4.

FIG. 6 is a front cross sectional view similar to FIG. 3 of another embodiment of the invention showing the block for the gun.

FIG. 7 is an enlarged view of one of the shutoff members.

FIG. 8 is a cross sectional view taken on line 8--8 of FIG. 6.


Now with more particular reference to the drawings and referring now specifically to FIGS. 1-5 of the drawings, the spray gun 10 includes a block 12 supported in depending relation to a generally T-shaped plate 13 by fastener bolts 21. The T-shaped plate 13 has a narrow shank extending perpendicularly from one edge portion of the transverse part of the plate 13, as illustrated in FIG. 1, and includes a depending hand grip 11 secured to the end portion thereof by fastener bolts 20 with the hand grip 11 generally being parallel to but spaced from the block 12 with the hand grip adapted to be received in the palm portion of the hand and to be engaged by the fingers for supporting the spray gun 10 for manipulation thereof in the usual manner of supporting and manipulating a spray gun device.

Mounted in the block 12 is a nozzle assembly, generally designated by the numeral 22, with the nozzle assembly being controlled by an elongated control rod 15 that is reciprocally received in a bore 23 in the block 12 and which extends toward the hand grip 11. The rod 15 extends loosely through a slot 24 in an actuating handle 14 which depends from a transverse pivot pin 25 received in a recess 26 in the bottom surface of an intermediate portion of the frame 13 whereby the actuating handle 14 is disposed between the frame 13 and the hand grip 11 and adjacent the hand grip 11 so that the fingers of a person manipulating the spray gun may easily grip the actuating handle 14 to pivot it toward the hand grip 11 which moves the control rod 15 toward the hand grip 11. The slot 24 in the actuating handle 14 provides a space for the control rod 15. The end of the control rod 15 remote from the block 12 is slidably and guidably received within a threaded insert 27 in the hand grip 11 which has a bore therethrough communicating with a bore 28 extending through the hand grip with the bore in the insert 27 receiving the end of the rod 15, thus guiding the rod 15 for linear reciprocation.

For biasing the control rod 15 toward the nozzle assembly 22, the bore 28 is provided with a compression coil spring 29 which has one end engaging the end of the control rod 15 and the other end engaging an adjustable externally threaded set screw 30 which forms a closure for the bore 28 and an adjustable abutment for the spring 29 thereby enabling the closing bias of the spring on the control rod 15 to be varied. Thus the spring 29 will bias the control rod 15 to a normal position toward the nozzle assembly 22 and will also return the actuating handle 14 to its normal position spaced away from the hand grip 11. The pins 31 and 32 extend through control rod 15 and one pin 31 and 32 will engage each side of the actuating handle 14.

The nozzle assembly 22 includes an end cap 18 that may be of generally cylindrical construction and provided with threads 34 on the inner end thereof for threading into a threaded recess 33 in the block 12. Opposed side edges of the end cap 18 are preferably flattened at 35 to facilitate threading and unthreading of the end cap 18 in that the flat portions 35 provide for easier gripping thereof or enable a wrench to be employed for assembling and disassembling of the nozzle assembly. Also, the end cap 18 is provided with a passageway or orifice 36 extending longitudinally therethrough with the inner end of the end cap receiving the outer nozzle part 17.

The outer nozzle part 17 has an outer cylindrical part 37 which has a tube 38 integrally fixed thereto. The nozzle part 17 may be made of Teflon or other suitable material, as may the inner nozzle part 16. The conical hollow end surface 39 is formed on the inner end of the outer nozzle part 17 and the conical end 39 rests on the convex conical end 40 of the inner nozzle part 16. A tapered bore 41 is formed through the outer nozzle part 17 which terminates in outer end orifice 42. The inner nozzle part 16 has a cylindrical part 44 that terminates in the frusto-conical end 40. Cylindrical part 44 is snugly received in bore 58 in block 12. End 40 forms a seal with the surface of the internal conical end 39 on the outer nozzle part 17. The inner nozzle part 16 has a bore 45 that receives the locating pin 46 thereby holding the inner nozzle part 16 in proper location so that the bores 48 and 49 will connect to bores 52 and 53 in the block 12. Bores 52 and 53 communicate through lateral bores 54 and 55 with the threaded bores 56 and 57 that receive the hose fittings 58 and 59 connected respectively to two parts of the material being sprayed. The inner nozzle part 16 also has a central bore 47 which slidingly receives the control rod 15 and is slightly smaller than the control rod 15 so that the control rod 15 forms sliding engagement with the bore 47 and thus provides a seal preventing the escape of material. Spaced bores 48 and 49 extend through the nozzle part 16 and terminate at 40. The bores 48 and 49 communicate with bores 52 and 53 in the block 12, which in turn communicate with bores 56 and 57, as aforesaid.

Tangential bores 50 and 51 in inner nozzle part 16 communicate from bores 48 and 49 and with the central bore 47. Bores 50 and 51 are offset from the center diameter of the inner nozzle part 16 and extend toward the center of the inner nozzle part 16 and toward the conical end 40. It will be noted that the bore 50 is disposed closer to the conical surface 40 than the bore 51. Thus the bore 51 is shut off by control rod 15 moving toward the outer nozzle part 17 before bore 48 is shut off by the control rod 15 as it moves toward the conical surface 40 thereby allowing the material through the bore 50 to flush out the material from the nozzle before both passages or bores 50 and 51 are closed.

In the embodiment of the invention shown in FIGS. 6, 7 and 8, the gun 110 has a head block 112 having the cylindrical bore 133 in the form of a recess for receiving an inner nozzle part as in the embodiment of FIGS. 1-5. Openings 160 and 161 through the head are intended to register with bores such as 48 and 49 in a nozzle part, such as shown in FIGS. 4 and 5. Lateral bores 163 and 164 communicate with bores 160 and 161 and threaded counterbores 155 and 156 communicate with bores 163 and 164. A supply of the material to be sprayed, which include a first material and a second material, are intended to be connected by suitable hose connections to threaded counterbores 156 and 157 which have continuation bores 154 and 155 that communicate with the bores 163 and 164. The threaded nuts 168 are received in the threaded counterbores 165 and 166 and these nuts 168 have an unthreaded bore 169 that receives the rods 170. Rods 170 are connected at their outer ends to handles 171 and are freely rotatable in bores 169. A Teflon insert 180 is disposed in a counterbore in the inner end of the nut 168 and provides a seal. The rod 170 has an axial hole 172 which communicates with a lateral hole 173. The rod 170 extends through the bore 163 and the hole 173 is disposed adjacent the hole 154. Thus when the handle 171 is rotated to the position shown in FIG. 6, the hole 163 registers with the hole 154 so that material can flow from the tank connected to the threaded counterbore 156 through the bore 154, lateral hole 173, the axial bore 172 and the bore 163 to the hole 160 and out through bore 48, bore 50 and bore 41 through the nozzle. When the handle 171 is rotated to the position at right angles to the position shown in FIG. 6, the hole 173 will be out of alignment with the bore 154 so that no material can flow. A Teflon insert 174 provides a seal around the rod 170 to prevent the leakage of material. A collar 181 is attached to rod 170 and limits its outward movement. Cleanout holes 183 are formed in body 12. Holes 183 align with hole 173 in rod 170 when the rod is rotated to OFF position. Thus an instrument can be inserted through bores 183 into hole 170.

The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.