Spray machine for giving a texture to drywall

A portable wall and ceiling texture machine applicator is housed in a relatively small cabinet mounted on relatively large rear wheels for easy pulling up stairs and on swivel front casters for easy steering. A first material delivery system includes a variable speed pump which delivers particulate texture material at a selected flow rate which enables a creative application of texture. A completely separate delivery system delivers pressurized air to a spray head which merges the particulate texture material and pressurized air to spray it onto a wall or ceiling. Separate power cords supply energy for delivering the particulate texture material and pressurized air so that existing 15-amp house supply circuits may be used. The spray head may be on either a pole gun or a hand gun. A check valve on the spray head prevents a back flow of the particulate material when the spray head is turned off.

This invention relates to equipment for installing texture particulate 
material on ceilings and walls and more particularly to tools for giving a 
texture, especially--but not exclusively--to drywall. 
For convenience of expression, the terms "particulate texture material" or 
"texturing material" will be used herein to describe any suitable 
materials which may be used to apply a textured coat to walls or ceilings. 
Many people who work in the field refer to this material as "mud." 
Examples of such particulate materials are plaster, cement, or the like. 
Another material is a lightweight material designed to acoustically treat 
a surface to make a quieter room. A machine for spraying particulate 
texture material has the power to deliver the lightweight acoustic 
material; however, a machine for spraying acoustic material does not 
usually have the power to deliver the heavier particulate texture 
material. 
For centuries, buildings have had plaster walls, many of which were 
textured, so that currently, many people who want a traditional appearance 
in their buildings have textured walls. The traditional plaster walls may 
be textured by using any of many different techniques, working the surface 
while the plaster is still wet. However, by now, drywall construction has 
supplanted much--if not most--of the plaster walls that were used 
heretofore. Drywall comprises relatively large panels of plaster, or the 
like, with cardboard bonded onto opposite sides of the panel. 
Usually, the drywall is painted after it is installed, which gives an 
appearance that is practically indistinguishable from a painted plaster 
wall. If a separate texture coat is applied before such textured walls are 
painted, they have a distinctive surface appearance ranging from a 
stippling to a coarse hill and dale effect, in many different patterns. 
Prior labor intensive techniques have been used to texture the drywall 
through the use of various manual processes. However, these processes have 
been slow and have produced operator fatigue. Usually, these processes 
have involved working with rollers which have to be pressed against the 
wall while heavy, hard to work particulate materials are distributed with 
a surface pattern. As a result of this prior history of texturing ceiling 
and wall surfaces, there are now many surface effects that people 
recognize, such as those effects which are now known as: acoustic, spray 
splatter, knockdown splatter, or orange peel. Since texturing is now, in 
essence, practically an art form or at least a skilled craft, these 
effects may vary greatly from job to job; nevertheless, anyone who is 
familiar with texturing walls or ceilings is able to readily identify the 
patterns. For example, each of the "orange peel" surfaces prepared by 
different people might look quite different, if placed side by side. 
However, all of those who are skilled in the art will easily agree that 
each has an "orange peel" surface. 
Hence, if new and novel means for and method of texturing surfaces is 
provided, they should include a way for the workman to express his 
"artistry" by making an individualized surface while preserving his 
ability to produce recognized patterns. 
While the foregoing comments have been limited to a discussion of plastered 
walls, by way of example, the invention is also applicable to other 
textured wall surfaces, such as cement and stucco, for example. 
In the prior art, truck-mounted equipment has sometimes been used to 
provide some of these features, but portable equipment is often preferred. 
For example, the workman may have to transport it to a second or third 
story in a house with no elevator. When the user is a single workman who 
is alone on a job site, it is easy to see that he cannot lift a heavy 
machine to an upper floor. Thus, smallness and portability becomes an 
important factor. However, it is not easy to scale down truck-mounted 
equipment in order to provide portable equipment. 
When one stops to understand that a particulate texture material applicator 
machine of the described type is working with wet plaster or cement, the 
need for easy and complete cleanup becomes apparent. This heavy 
particulate texture material includes water, and its oxidizing effect, 
together with the corrosive effect of the particulate material, causes a 
hopper, wall, or tank holding the plaster or cement to rust or corrode. 
Thus, making a hopper of fiberglass or another strong, lightweight, easily 
cleaned material is not just an option; it-may be a difference between the 
commercial success and failure of the texture applicator machine. 
An operator who is spraying ceiling and wall textures must apply a fairly 
thick, heavy level of textured material which has a thick body. Insofar as 
the textural material is concerned, the failure to spray the heavy 
material with sufficient force produces three problems. First, the final 
product on the wall does not present a desired appearance. Either it is 
not adequately uniform, or it has the "look" of a lightweight coverage. 
Second, the operator usually has to work at such close distances that he 
must wear stilts and do other awkward things in order to apply any fairly 
acceptable surface. Third, the operator does not have the flexibility 
required to produce exactly the surface effect that he wants to produce. 
A second consideration involves the applicator machine itself. If there is 
an inadequate delivery of the particulate texture material by the machine, 
the material tends to plug up in a hose or spray head, or the machine 
otherwise fails to deliver the proper amount of material at the proper 
pressure. For example, there can be a build-up of texture material within 
the material delivery system, especially when the spraying pauses or 
stops. Thus, when the machine is again turned on, a pressure surge occurs 
to cause a blob or blobs of the material to splatter out of the spray 
head. As a result, the operator may have to keep available a special 
bucket which he uses to receive the initial spray after the end of a pause 
or after a switched-off condition. This use of a bucket to collect the 
initial material delivery wastes texture material and increases the 
clean-up cost, tiring the operator who has to carry off the bucket of 
wasted material. 
One should also distinguish between spraying a heavy particulate texture 
material, of the type which is usually called "mud", and spraying a 
lightweight acoustic material. The "mud" is a heavy mixture which is 
intended to give an appearance of a construction type of material, such as 
plaster, concrete, or the like, for example. The acoustic material is a 
lightweight substance primarily intended to make a room quieter without 
making an unduly noticeable surface appearance. These two types of 
materials often entail the use of different applicator machines. 
Yet another consideration relates to the remote control of spraying carried 
out from the spray gun, as compared to control from the applicator 
machine. If the operator can turn the machine off and on remotely, it 
greatly reduces the probability that there will be surges expelling blobs 
of material. On the other hand, the electrical controls on the spray gun 
are difficult to provide, since they are subjected to rather severe 
mechanical stress and problems. These which might occur because the 
particulate texture material may leak, the operator may have the texture 
material on his hands, he may have to hold the spray gun in an awkward 
position to reach certain surfaces, or he may have trouble manipulating 
all of the equipment, such as hoses, pole, etc. while pushing buttons, 
turning knobs, etc. 
Yet another consideration is how far the spray gun may be moved from the 
applicator machine and still remain operative. If the machine is able to 
successfully deliver heavy "mud" through a fifty-foot hose, there is no 
need to move the applicator machine while covering walls and ceilings in 
many houses. In one case, it was found that with a fifty-foot hose, an 
operator could cover a four-bedroom house with a two-car garage in only 
three hours. If the application machine was only able to deliver the heavy 
particulate texture material through a much shorter base, it is 
conceivable that spraying the textured material over the same house might 
have required much more than the three hours, due to the additional time 
in moving the machinery and the supply of texturing material, cleaning up, 
etc. 
Accordingly, an object of this invention is to provide new and improved 
means for and methods of applying a great variety of textures to ceiling 
and wall surfaces, especially to drywall. Here, an object is to provide a 
faster, less fatiguing way to apply such textures to surfaces in a great 
variety of different patterns. In particular, an object is to give a 
workman artistic freedom to apply a texture of his individual design while 
enabling him to produce known surface patterns. 
Another object of the invention is to better simulate known textures which 
are applied to plaster walls, without requiring substantial labor. In 
particular, an object is to accomplish this end without requiring an undue 
number of accessories. 
Another object is to provide these objects with easily portable equipment. 
Here, an object is to provide an applicator machine which is light and 
easily portable and yet is able to reliably deliver heavy, mud-like 
texturing material through long hoses to a spray head. In this connection, 
an object is to remotely control the applicator machine from a spray head 
at the end of a long hose. 
Yet another object of the invention is to provide an applicator machine 
which does not produce pressure surges and unwanted blobs or splattering. 
In keeping with an aspect of the invention, these and other objects are 
accomplished by a machine which is built to spray most construction 
coatings, with a heavy aggregate laden particulate texture material that 
is small enough to pass through one of the orifices at the far end of a 
pole gun. The gun sprays mill mixes, acoustics, drywall mud, and 
waterproofing plus many other forms of particulate materials. This machine 
has a first material delivery system with a variable speed pump driven by 
a first electric motor, to propel the heavy particulate texture material 
through a hose to a first spray head. A second and separate delivery 
system with a compressor driven by a second motor delivers air through a 
completely separate hose to the spray head, where the air system merges 
with the particulate texture material delivery system in the spray head. 
The two delivery systems are completely separate so that if necessary, 
they may be run off completely separated fused electrical circuits, which 
may eliminate the need to run a special power line to drive the applicator 
machine. The spray head delivers material in a wide variety of patterns, 
ranging from fine wall textures to heavy "ceiling acoustic" splatter.

The inventive texture applicator machine 20 is seen in FIGS. 1 and 2 as 
including a housing 22 made of any suitable material and containing a 
hopper 24 made of a suitable non-rusting, non-corroding material, such as 
fiberglass, for example. Since a light weight is desirable for 
portability, the entire housing may also be made of fiberglass. A pair of 
fairly large wheels 26 support one end of the machine so that it may be 
pulled up a flight of stairs by manipulating suitable handles 28 which are 
located over the large wheels. The opposite end of the machine is 
supported by swivel casters 30 for easy steering. 
A pole gun 34 is connected to the machine via a suitable particulate 
texture material hose 36 which is connected to the output nipple 38. The 
workman may apply the particulate texture material to a ceiling or wall by 
simply holding the pole gun near it and operating controls on either the 
machine or pole gun. 
Mounted on the machine 20 are a first set of controls 40 (FIG. 3). A set of 
remote controls is mounted on the pole gun or hand gun. A compressor may 
be switched ON/OFF at 42 in order to supply pressurized air. At 44, the 
pump for the particulate texture material may be switched ON/OFF or 
switched to remote in order to transfer the controls to the pole gun. A 
suitable rotary control knob 46 may drive the pump at any one of a 
suitable variety of speeds. 
The assembly of the texture applicator machine is best seen in the exploded 
view of FIG. 2. 
An important aspect of the invention is that two completely separate 
systems are provided for delivering air and texturing material to the pole 
gun. This way both the air and the texturing material may be controlled 
independently of each other. A suitable frame 48 supports the parts of the 
machine. A first major assembly is a motor driven air compressor 50 and a 
second major, and completely separate, assembly is a motor driven, 
particulate material pump 52. The compressor assembly 50 (FIG. 4) 
comprises a compressor 56, bearing and support 58, a lubricant fitting 60, 
retain rings and grease seals 62, 64, gasket 66, shaft key 68, compressor 
rotor and vane 70, compressor body 72, bearing 74, end plate 76, and seal 
78. These parts are assembled and mounted on frame 48 (FIG. 2). A first 
electric motor 80 is also mounted on the frame, in line with the 
compressor 56, and joined to compressor shaft 82 by coupler 84. Compressed 
air is delivered by an air hose 88 to an end fitting 90. The end fitting 
90 and hose are designed to have the same, relatively large (such as 
one-half inch) diameter so that air flows to the pole gun without 
turbulence. The air pressure is displayed on a suitable gauge 92. A relief 
valve 94 may be operated to control or eliminate pressure in the air hose 
88. 
The particulate material pump 52 comprises a second motor 96, preferably a 
D.C. gear motor (FIG. 2), driving through gear box 98 which is connected 
via a chain drive 100 to a pump 102. The chain drive 100 is suitably 
connected to the gear box shaft by key 104 and to shaft 101 of the pump 
102 by key 106. The pump is attached to the frame 48 by stator/cradle 
members 108, 110. An upper stator/cradle clamp 112, 114 bolts onto cradle 
member 108, 110 to secure pump 102 in place. The bottom outlet of hopper 
24 is connected to pump 102 at its input 116. 
The compressor motor 80 is electrically connected to control box 40 by a 
first power cord 86. The pump motor 96 is connected to control box 40 by a 
second power cord 85. If desired, the control box may be connected to a 
suitable power outlet by a single power cord 87, but that might require a 
heavy amp or higher voltage circuit which is not always available in a 
house in some foreign countries. However, the two separate power cords 85, 
86 from the pump and compressor may be plugged into separately fused 
15-amp wall outlets. In many operations, this use of two 15-amp circuits 
avoids the need to string a special power line in order to use the texture 
applicator machine. This feature is of particular importance in some 
countries having power distribution systems which are not capable of 
driving a heavier duty motor which might be required if a single-motor 
power cord is used. 
The details of the particulate texture material pump 102 are shown in FIG. 
5. The input shaft is mounted on bearings 118, 120. A suitable seal 
assembly 122 seals one end of the compartment 124 which receives the 
particulate texture material. An auger 126 transports the particulate 
texture material to an outlet 128 on the right, as viewed in FIG. 5. In 
the outlet area 128, a central worm drive member or rotor 130 rotates to 
move the particulate texture material in a rightward direction between it 
and stator 132. The pumped particulate texture material exits at 136 (FIG. 
2), to a hose 36 (FIG. 2), connected to nipple fitting 136. A material 
relief valve 138 may be set to open under a selected pressure of material. 
The hose and fittings preferably have a uniform diameter which are 
selected to provide an unrestrained and free flow of the material to the 
pole gun. 
The details of pole gun 34 are seen in FIG. 6. A control assembly 142 opens 
and closes paths from the hose 36 through which the particulate texture 
material moves from the pump 102 to the material tube 139 of the spray gun 
34 and air hose 141a. The rest of the path to the output end of gun 34 is 
completed via particulate material tube 139. An air hose 146 feeds 
compressed air from air line 141a to the gun 34. 
The operator's remote control assembly 142 (FIG. 8) provides separate 
controls over tile separate flows of both the heavy particulate texture 
material and compressed air. From an air hose 141a extending back to the 
texture applicator machine (FIG. 1), the compressed air enters the 
operator remote control assembly 142 via an air ball valve 143. The valve 
should open and close with a quarter turn rotation of a handle 144 which 
opens a passageway formed by a hole which aligns with the passage. The 
hole and the passageway should have substantially the same diameters so 
that air flows smoothly and without turbulence or reflection. When the 
handle 144 is turned back a quarter turn, the valve rotates so that the 
hole through it is transverse to the passageway and a solid side of the 
valve blocks the passageway for pressurized air. 
The particulate texture material also travels from the applicator machine 
through a hose 36 (FIGS. 1, 6) to a ball valve 145 (FIG. 8) controlled by 
a turn of a handle 146a. As with the pressurized air delivery system, the 
ball in valve 145 for the textured material delivery system has a bore 
with the same diameter as the inside diameter of hose 36 and material tube 
139 (FIG. 6) so that the heavy particulate texture material flows smoothly 
and without turbulence. 
An electrical switch 149 is operated or released by a push button 150. The 
switch and push button may be covered in whole or in part by a suitable 
elastomer boot which keeps foreign material out of the switch mechanism. 
The boot is flexible enough not to interfere with push button operation. 
An electrical power cord 151 extends from switch 149 to connector 152, to 
which any suitable power line may be connected for extending a circuit 
back to operate the applicator machine. 
A bracket member 147a receives U-bolts 147b, 148 which secure the 
particulate texture material ball valve 145, air ball valve 143, and an 
electrical switch 149 in place and relative to each other. 
When the parts are so secured to the bracket 147a the push button 150 lies 
in the path followed by handle 146a on the particulate texture material 
ball valve 145. Thus, when handle 146a is moved to a position which opens 
the ball valve 145 to deliver the material, push button 150 is pushed by 
the handle to close switch 149 and start the particulate material pump 52 
(FIG. 2). When the handle 146a is moved to a position which closes the 
valve 145, the push button 150 is released to open the switch 149 and turn 
off the particulate material pump 52. 
One problem is that as the compressed air is switched off, the particulate 
texture material could force itself back into the air hose 141 before the 
pressure of the particulate texture material subsides in material tube 
139. Therefore, a check valve 153 is provided in hose 141 to prevent a 
backward flow while allowing a forward flow of pressurized air. 
The pressurized air and particulate texture material delivery systems are 
completely separate, beginning with the two motors 80, 96 and extending 
over hoses 141a, 36 to remote controls 142, material tube 139, air hose 
146, and check valve 153 to spray gun head 34 where the delivery systems 
merge to spray the particulate materials onto the walls or ceilings. 
Thus, to spray the heavy particulate texture material, the operator first 
opens the compressed air valve 143. Then, holding the material tube 139 
(FIG. 7) in one hand and its control handle 146a in the other hand, the 
operator modulates the flow of the particulate texture material out the 
spray gun head 34 by opening and closing ball valve 145 (FIG. 8). 
A hand gun (FIG. 7) may be provided to reach places which are in restricted 
or other areas where the pole gun would be awkward to use. The principal 
parts of the hand gun are left and right housings 156, 158 which may be 
secured together by means of bolts 160. An electric switch 162 may be 
placed in the housing 156 with a control button which projects out a slot 
163 in order to turn the pump 102 (FIG. 2) on and off responsive to thumb 
pressure applied by the person holding the hand gun of FIG. 7. A trigger 
assembly 164 drops onto the housing to open a valve and deliver 
pressurized air. Thus, one would squeeze the trigger 164 with his fingers 
while pressing the electrical switch 162 with his thumb in order to 
deliver a compressed air driven spray of particulate texture material. 
The particulate texture material delivery system begins at inlet 166 and 
exits at an orifice plate 168 connected to the outlet 170 of the gun. 
Plate 168 is secured to the gun by bolts 172 which fit into slots 174. 
The air supply is delivered via air line 141a through an end fitting 176 
connected to a rear bushing 178. A seal and washer combination 180 
provides a seal at the pressurized air entrance to the gun. Spring 182 
biases the trigger 164 to a normally closed position, where no air is 
delivered. An air stem pipe 184 carries the air from rear bushing 178 to a 
front bushing 186 where a "Neoprene" seal 188 joins it to a selected one 
of many alternative orifices 190, 192. 
Each of the guns shown in FIGS. 6, 7 has mean for adjusting a distance 
between the air stem and the nozzle tip. This means is most apparent in 
FIG. 7, where the air stem 184 has a threaded end 191 which receives a 
selected one of the air orifice nozzle tips 190, 192. The distance between 
the air stem and nozzle tip is adjusted by turning the tip 190, 192 more 
or less further onto the end of the air stem. To facilitate making this 
adjustment, an air stem socket tool 193 is supplied with the gun. This 
socket is inserted into an end of the gun, over the orifice tip, and then 
turned. 
In operation, all of the appropriate parts are first connected together. 
Then, three to four gallons of soapy water are placed in the tank or 
hopper 24 (FIG. 2). The soapy water is run through the pump 102 and hose 
36 to help free the rotor 130 (FIG. 5) and to lubricate the particulate 
texture material line. This soapy water procedure should be repeated for 
each operation or if the pump has sat idle for a period of time. After all 
of the soapy water has been pumped out of the hopper 24, the pump is 
turned off, and the particulate texture material is added into hopper 24. 
The particulate texture material line should always be wet before pumping 
in order to minimize friction. 
The pump 102 can be operated manually from the OFF/ON switch 44 (FIG. 3) 
located on the control box 40. When the switch 44 is in the "ON" position, 
the valve on the gun should be "OPEN" to prevent a pressure build-up in 
the particulate texture material line. The OFF/ON switch 44 is preferably 
connected to over-ride the switch at 149 (FIG. 8) on the pole gun (FIG. 
6). If the switch 44 is set to "remote", the operator is able to turn the 
pump on and off from the pole gun. With the switch 44 in the "remote" 
position, an opening of the particulate texture material valve 145 (FIG. 
8) and, therefore, operation of switch 149 automatically turns the pump on 
and closing it automatically shuts off the pump. If the hand gun is used, 
the same control is carried out by pushing or releasing a button on switch 
162, which is on the left side of the gun. 
The pump speed is varied by adjusting a "Pump Speed" control 46 (FIG. 3) 
located on control box 40. The control positions are number 0-10, with "0" 
being no flow and "10" being maximum flow at 2 GPM. The speed control dial 
is set on "0" when pump 102 is started in order to avoid damage to the 
pump assembly. 
The machine is now ready to spray the particulate texture material. In 
order to use the machine, it is essential to obtain a proper mix. When 
mixing drywall acoustic and wall texture, it is best to make the mix a 
little stiffer. 
Pattern adjustments of the texture formed by the particulate texture 
material, when sprayed on a ceiling or wall, are determined by three 
factors: (1) air supply; (2) particulate texture material orifice size; 
and (3) particulate texture material flow. All three factors must be 
considered when selecting or adjusting a pattern of texture. 
The air supply is adjusted by reading air pressure meter 92 (FIG. 2) while 
adjusting the relief valve 94. After a desired air pressure is obtained, a 
locking nut is tightened. 
Each gun has at least four nozzle tips (3/8", 5/16", 1/4" 3/16"). The 
particular tip that is selected depends to a large extent on the size of 
the aggregate in the particulate texture material that is being used. The 
tip must be large enough to allow the aggregate to flow freely. Tip size 
also affects the coarseness or fineness of the pattern. The larger the 
tip, the more coarse the pattern. When spraying acoustic particulate 
texture material, 3/8" or 5/16" tips are the most popular. To obtain a 
very fine wall spray such as an orange peel texture, the 3/16" or 1/4" tip 
should be used. If there is a straight stream of particulate texture 
material, the air stem and air pressure should be adjusted until the 
straight stream disappears, thus leaving a uniform round spray. 
By using the pump speed control 46 (FIG. 3) the flow rate of the 
particulate texture material can be varied. The greater the particulate 
texture material flow rate, the more coarse the texture pattern. The 
following chart is a rough guide showing how the various factors combine 
to produce different spray patterns. 
______________________________________ 
Range Of 
Nozzle Distance Particulate 
Tip Between Air 
Texture 
Orifice Stem And Material 
Pattern Size Air Volume Nozzle Tip 
Volume 
______________________________________ 
Acoustic 3/8" Med-High 3/8"-1/2" 
Med-High 
Acoustic 5/16" Med-High 3/8"-1/2" 
Med-High 
Fog 3/16" High 1/16" Low 
Orange Peel 
1/4" Med-High 1/8"-3/16" 
Low 
Heavy 5/16" Low 3/8"-1/2" 
Med-High 
Splatter 
______________________________________ 
Please keep in mind that all factors are interrelated 
When ready to spray, the nozzle tip is usually off of the gun until the 
particulate texture material has reached the nozzle head. After the water 
has been pumped from the hose, a raw aggregate appears. When mixed 
particulate texture material appears at the gun head, the pump is turned 
off and an appropriate tip is attached. It is then a good idea to test for 
the pattern on either cardboard or a scrap of wall-board. Once the various 
adjustments have been verified, the worker is free to practice his 
artistry. 
Clean up of the inventive machine is quite easy, the procedure being: 
1. Flush out the remaining material from the hopper 24; 
2. Continue to run warm water through pump 102 and hose 36 until clean; 
3. Disconnect hand gun (FIG. 7) or pole gun (FIG. 6); 
4. Disconnect material hose 36 at pump 102; 
5. Place a sponge, about twice the size of the hose diameter, in the hose. 
Connect hose 36 to pump 102; 
6. Pump water until sponge has been forced through the hose 36; and 
7. Flush water through the relief valve 138 after each spray operation. The 
relief valve must be kept clean in order to function properly. 
Those who are skilled in the art will readily perceive how to modify the 
invention. Therefore, the appended claims are to be construed to cover all 
equivalent structures which fall within the true scope and spirit of the 
invention.