Parts coating apparatus and method

A parts coating apparatus and method for applying coating material to parts. The apparatus comprising a housing, a motor supported by the housing, a head driven by the motor and rotatably mounted to the housing. A basket, to contain the parts, is detachably coupled to the head. The basket is generally perforate to the coating material. A coating compartment separably encloses the basket. The coating compartment is generally imperforate to the coating material. A spray tube, to spray the coating material communicates with the coating compartment. A coating material system supplies coating material to the spray tube. A control system selectively actuates the motor and the coating material system.

BACKGROUND OF THE INVENTION 
In prior art automatic coating and painting systems, small parts and 
components are placed in a basket and the basket is coupled to a machine 
which dips the basket one or more times in a reservoir of paint or other 
coating material. The basket is then withdrawn from the reservoir and spun 
rapidly to remove any excess coating material from the parts. 
This prior art coating process is effective, but has several severe 
limitations. The reservoir must contain a large amount of coating material 
and the coating material in the reservoir can become contaminated after a 
coating cycle from contaminants on the parts being coated. This degrades 
the quality of subsequent coating runs unless the coating material is 
changed. In practice, the coating material in the reservoir is replaced 
frequently to ensure against contamination and resultant poor quality 
parts coating. This results in usage of large amounts of coating material, 
frequent machine down time and a relatively large coating cost per part 
produced. 
Another problem with prior art coating machines is that coatings are 
applied as a relatively thick single layer. If fast drying coating 
materials are used, parts in contact with each other adhere together as 
the coating partially dries, resulting in imperfections on finished parts. 
Prior art coating machines thus cannot readily use coating materials which 
could dry appreciably before parts were removed from the coating machine 
and spread on drying tables. 
Additional problems of prior art coating machines are difficult loading, 
unloading and cleaning procedures. 
It is therefore highly desirable to provide an improved parts coating 
apparatus and method for the high volume coating of small parts. It is 
also highly desirable to provide an improved parts coating apparatus and 
method for spray coating parts using both conventional and fast drying 
coating materials. It is also highly desirable to provide an improved 
parts coating apparatus wherein the excess coating material can be 
automatically recycled through a filtering system back to the reservoir 
containing the coating material. 
It is yet also highly desirable to provide an improved parts coating 
apparatus in which the parts can be coated under an inert gas atmosphere. 
It is yet also highly desirable to provide an improved parts coating 
apparatus which centrifugally removes excess coating material and which 
has an improved locating mechanism which stops the spinnning basket of 
parts being coated in a specific position from which the basket can be 
easily withdrawn from the apparatus. 
It is still further highly desirable to provide an improved parts coating 
apparatus which has all of the above features. 
Finally it is highly desirable to provide a method for coating parts by 
loading parts into a basket, placing the basket in a coating compartment, 
spraying the parts with a coating material while the basket is in the 
coating compartment, agitating the parts in the basket while the basket is 
in the coating compartment, removing the basket from the coating 
compartment, and unloading the parts from the basket and an apparatus for 
performing the method. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide an improved parts 
coating apparatus and method for the high volume coating of small parts. 
It is another object of this invention to provide an improved parts coating 
apparatus and method for spray coating parts using both conventional and 
fast drying coating materials. 
It is another object of this invention to provide an improved parts coating 
apparatus wherein the excess coating material can be automatically 
recycled through a filtering system back to a reservoir containing the 
coating material. 
It is another object of this invention to provide an improved parts coating 
apparatus in which the parts can be coated under an inert gas atmosphere. 
It is another object of this invention to provide an improved parts coating 
apparatus which centrifugally removes excess coating material and which 
has an improved locating mechanism which stops the spinning basket of 
parts in a specific position from which the basket can be easily withdrawn 
from the machine. 
In the broader aspects of the invention there is provided a parts coating 
apparatus and method for applying coating material to parts. The apparatus 
comprising a housing, a motor supported by the housing, a head driven by 
the motor and rotatably mounted to the housing. A basket, generally 
perforate to the coating material, for containing the parts, is detachably 
coupled to the head. A coating compartment generally imperforate to the 
coating material, separably encloses the basket. A spray tube, to spray 
the coating material, communicates with the coating compartment. A coating 
material system supplies coating material to the spray tube, and a control 
system selectively actuates the motor and the coating material system.

DESCRIPTION OF A SPECIFIC EMBODIMENT 
Referring to FIGS. 1 and 2, the parts coating apparatus 10 of the invention 
is shown. A housing 11 supports motor 12, which has a shaft 22. The shaft 
22, drives a head 15. A basket 16 containing the parts to be coated is 
detachably coupled to the head 15. The basket 16 is enclosed within a 
coating compartment 32, which may be separated from the basket by vertical 
movement of a coating tank 18. Disposed within the head assembly 15 is a 
spray tube 30 located to spray the parts in the basket 16 enclosed in the 
coating compartment 32. The parts are sprayed with coating material 
supplied by a coating material system which includes a reservoir 20 of 
coating material connected to the spray tube 30. The basket 16 of coated 
parts is removed from the head 15 by a shuttle assembly 40 and a second 
basket 16 is placed on the head 15 by a second shuttle assembly 40. 
The motor 12 moves the head assembly 15 and the basket 16 during all or 
part of the time the parts are being sprayed. The motor 12 is an air motor 
actuated by compressed air supplied by a fluid control circuit 17 shown in 
FIGS. 7 and 8. The air motor 12 is rapidly reversible, i.e., rapidly 
changes direction of rotation and rapidly accelerates back up to speed. 
The parts are agitated by first rotating the motor 12 in one direction 
then in the opposite direction. When the direction of rotation of head 15 
and the basket 16 is charged, the parts are tumbled. This ensures that the 
various surfaces of the parts are exposed to the sprayed coating material 
and that the parts do not adhere to each other or the basket 16 while they 
are being sprayed. After spraying, the motor 12 spins the head 15 and 
basket 16 to centrifugally remove excess coating material from the parts. 
The excess coating is collected in a coating tank 18 for return to the 
reservoir 20. The movements of the head 15 and the spraying of the coating 
material are controlled by a control system consisting of fluid control 
circuit 17 shown in FIGS. 7 and 8 which actuates the motor 12 and the 
coating material system and an electrical control circuit which operating 
through the fluid control circuit 17 and in accordance with the user's 
selections, controls the sequence, duration, and timing of the actuation 
of the movements of the motor 12 and the spraying of the coating material. 
The housing 11 in a preferred embodiment of the invention 10, includes a 
main portion 36, and two shuttle portions 48. In addition the housing 11 
includes two side portions 42 to stabilize the housing 11 against 
overturning. The main frame 36 consists of vertical corner supports 24 
joined to horizontal members 26, 28, 34, 35, 38, 46 covered by outer 
panels 25. The side frames consist of side horizontal members 50, side 
vertical members 52 and outer panels 54. The shuttle frames 48 consist of 
shuttle frame horizontal members 58, vertical members 60, and braces 62. 
The shuttle frames bear support rails 56 which extend into the main 
portion 36 of the housing 11. The main portion 36 of the housing 11 is 
provided with access openings 44 to allow for movement of the baskets 16 
on the support rails 56. In a specific embodiment of the invention, doors, 
operated by means of the fluid control circuit 17, could be provided to 
cover the access openings 44. In the embodiment described herein, the 
control system includes, attached to the housing 11, a control panel 13 
containing the electrical control circuit. 
In a specific embodiment of the invention 10, the housing 11 does not 
include side portions 42 and shuttle frames 48. In that embodiment, a 
single basket 16 is movable along support rails 56 which are mounted to 
and extend out from the housing 11. 
The motor 12 is mounted to horizontal member 28 and drives a shaft 22 which 
turns within guides 66, 68, 72 mounted to the horizontal members 28, 26, 
38, respectively. The shaft 22 engages a positive drive mechanism 14, 
which drives the head assembly 15. The positive drive mechanism 14 may be 
a timing belt and sprockets or a drive chain and sprockets or a gear train 
or an equivalent mechanism for driving the head 15 without slippage. FIG. 
2 shows a drive chain 69 and sprockets 71, 73. 
Referring to FIG. 3, the head 15 is shown to be rotatably mounted to the 
horizontal members 26, 38 of the housing 11 by bearings 76, 78 
respectively. The bearings 76, 78 are mounted to their respective 
horizontal members 26, 38 by bearing retainers 80, 82 and 84, 86 and bolts 
88, 90, all respectively or their equivalents. 
The head assembly 15 has a sleeve 74 to which the bearings 76, 78 are 
mounted by bearing retainers 96 and 98 and bolts 100, 102, all 
respectively or their equivalents. A central passage 92 extends through 
the sleeve 74. 
The head assembly 15 has a basket mounting 70 attached to the sleeve 74 by 
bolts 102 or their equivalents. The basket mounting 70 has a pair of 
parallel flanges 104 which extend inward below the basket mounting 70. The 
basket mounting 70 has a central opening 106 alligned with the central 
passage 92 of the sleeve 74. 
Mounted in the central passage 92 of the sleeve 74 are annular sleeve 
spacers 108, 110. The sleeve spacers 108, 110 may be bushings or bearings 
or their equivalents. 
Disposed within the central passage 92 of the sleeve 74 of the head 
assembly 15 is the spray tube 30. The spray tube 30 is joined to an air 
cylinder 94 supported by the horizontal member 28. The spray tube 30 is 
slidably mounted in the central passage 92. The spray tube 30 is movable 
between a retracted position and an extended position by actuation of the 
air cylinder 94 by pressurized air provided by the fluid control circuit 
17, shown in FIGS. 7 and 8. Guide members 126, 128 support the movement of 
the spray tube 30. A nozzle 112 is attached to the spray tube 30. The 
characteristics of the nozzle 112 are determined by the coating material 
used. It is generally desirable, however, to use a nozzle 112 which has a 
generally downward and circularly directed spray pattern. It is convenient 
to have engagable male and female threads or the equivalent on the nozzle 
112 and spray tube 30 to permit interchange of different nozzles 112 and 
replacement of worn nozzles 112. 
The nozzle 112 communicates with a longitudinal bore 114 in the spray tube 
30. The bore 114 communicates with a supply hose 116 connected to a pump 
118 which supplies coating material from the reservoir 20 through a filter 
120 and hoses 122, 124. In a specific embodiment of the invention the pump 
118 could be replaced by instead using pressurized air from the fluid 
control circuit 17. 
The basket 16 has an upper basket assembly having a frame 132 and panels 
134 which are formed of perforated sheet or screening or the equivalent. 
The basket is thus generally perforate to the coating material. The frame 
132 has upper and lower frame members 136, 138 held in spaced relationship 
by a series of pins 140, as shown in FIGS. 4 and 5. Mounted to upper frame 
member 136 are parallel basket rails 142 which project outward to couple 
with the flanges 104 of the basket mounting 70. The basket rails 142 have 
disposed between them an upper plate 144 which bears a central collar 146. 
The collar 146 is a brass bushing or the like and is sized and positioned 
to engage the spray tube 30 when the spray tube 30 is in the extended 
position. In a preferred embodiment of the invention 10, the spray tube 30 
is in the extended position whenever the head 15 and basket 16 are 
rotated. In that embodiment, the spray tube 30, acts as an axle upon which 
the basket 16 can rotate and the spray tube limits radial movement of the 
basket 16 to restrain the basket 16 as it rotates. Projecting outward from 
the upper frame member 136 are rotatably mounted rollers 148 which support 
the basket 16 during movement of the basket 16 on the support rails 56. 
The bottom of basket 16 is closed by a base plate 150 which has a 
transverse central axle 152, which is pivotably mounted to lower frame 
member 138. A vertical basket handle 154 is attached to the base plate 150 
and is retained in position by a catch 156 attached to the frame 132. 
Movement of the basket handle 154 tilts the base plate 150 discharging 
parts from the basket 16. In a specific embodiment of the invention, a 
perforate conical central core is disposed on the base p1ate 150. The core 
prevents parts from occupying the center of the basket 16 and thus not 
being adequately agitated and to direct the tumbling of parts in a radial 
direction in addition to the tangential tumbling otherwise provided. 
In other specific embodiments of the invention, manual or powered material 
handling means for tipping the basket 16 to discharge parts may be 
provided instead of the base plate 150. 
The baskets 16 are moved into and out of engagement with the basket 
mounting 70 and along the support rails 56 by shuttle assemblies 40. The 
duplicate shuttle assemblies 40 and baskets 16 of a preferred embodiment 
of the invention allow parts in one basket 16 to be coated while parts are 
loaded into and out of the other basket 16. 
The shuttle assemblies 40 each include two carriages 158 joined by a 
shuttle body 160. The carriages each have rotatably mounted carriage 
rollers 162 which ride against a support rails 56 when the shuttle 
assembly 40 is moved. A shuttle axle 164 is mounted to the shuttle body 
160 by pivot bushings 165. Attached to the shuttle axle 164 are a pair of 
fingers 166 which pivot with the shuttle axle 164. The fingers 166 are 
positioned to be pivotable into and out of engagement with the shuttle 
slots 168 in a basket 16. A link 170 connects the shuttle axle 164 to an 
air cylinder 172, which is attached to the shuttle body 160 by a plate 
173. The air cylinder 172 pivots the shuttle axle 164 when actuated by the 
fluid control circuit 17 shown in FIGS. 7 and 8. 
A side plate 174 extends from one of the carriages 158. The side plate 174 
is connected to an air cylinder 176 which moves the shuttle assembly 40 
along the support rails 56 when actuated by the fluid control circuit 17 
system shown in FIGS. 7 and 8. 
The shuttle assemblies 40 are each displaceable on the support rails 56 by 
an air cylinder 176 between three positions, inboard, outboard and 
standby. In the inboard position the shuttle assembly 40 is within the 
main portion 36 of the housing 11 and a basket 16 engaged by the fingers 
166 of the shuttle assembly 40 is held by the basket mounting 70. In the 
outboard position, the shuttle assembly 40 is in a shuttle portion 48 of 
the housing 11, and a basket 16 engaged by the shuttle assembly 40 would 
be supported by the basket rails 56 of a shuttle portion 48 of the housing 
11. 
A shuttle assembly 40 is displaced to the standby position after moving a 
basket 16 from a first position in the shuttle portion 48 of the housing 
11 to a second position in the main portion 36 of the housing 11 in which 
the basket rails 142 engage the flanges 104 of the basket mounting 70. The 
shuttle assembly 40 is then disengaged from the basket 16 by pivoting the 
fingers 166 and the shuttle assembly 40 is then moved to the standby 
position to permit the coating tank 18 to be raised. The standby position 
is at a minimum clearance distance so that after spraying is completed and 
the coating tank 18 is lowered the shuttle assembly 40 may engage the 
basket 16 with a minimum delay for travel of the shuttle assembly 40 along 
the support rails 56. 
The shuttle portion 48 of the housing 11 has mounted on it an unloader 177 
which has a bifurcated unloader arm 179 attached to an air cylinder 181. 
The unloader arm 179 is movable from a neutral position to an engaged 
position, by means of the air cylinder 181 to engage and move the basket 
handle 154, tilt the base plate 150 and discharge the parts from the 
basket 16. The air cylinder 181 is actuated by the fluid control circuit 
17 shown in FIGS. 7 and 8. 
The coating compartment 32 is formed by the tank ring 192 and the coating 
tank 18 and in addition a portion of the head 15 and a section of the 
horizontal member 38 enclosed by the tank ring 192. The coating 
compartment 32 is generally imperforate to the coating material, in order 
to contain the coating material. The coating compartment 32 additionally 
functions as armor to protect the user of the apparatus from injury should 
catastrophic breakdown of the basket 16 occur. In a specific embodiment of 
the invention, the coating compartment 32 is gas tight to pressurized gas. 
The coating tank 18 is mounted on a platform 208 within the housing 11. The 
platform 208 is vertically movable, to move the coating tank 18 between a 
lowered position in which the basket is separated from the coating 
compartment 32 and a raised position in which the coating compartment 32 
encloses the basket 16. Movement of platform 208 is provided by means of 
an air cylinder 210 controlled by the fluid control circuit 17 shown in 
FIGS. 7 and 8. Guide elements 212 attached to the platform 208, slide 
along guide rods 214 when the platform 208 is moved. 
The coating tank 18 has a drain. Attached to the drain 194 is a drain hose 
196 connected to the reservoir 20. The drain hose 196 may be disconnected 
from the reservoir 20 for disposal of used coating material. 
In a specific embodiment of the invention the coating material may be 
pumped from the drain hose 196 through a filter and a pump back into the 
reservoir 20. 
In a specific embodiment of the invention 10 described herein, a gas inlet 
130 extends through horizontal member 38 into the coating compartment 32 
so that a selected gas or combination of gases such as for example, the 
inert gas argon can be forced into the coating compartment 32. The gas 
inlet 130 is connected to a gas system 198 comprising a gas tank 200, a 
manual valve 202, a pressure regulator 204 and a slide valve 242 as shown 
in FIG. 8 to provide for release of the gas into the coating compartment 
32. Actuation of the gas system is provided by the fluid control circuit 
17 shown in FIGS. 7 and 8. 
In a specific embodiment of the invention the supply hose 116 can be 
selectively switched between the reservoir 20 and a tank of cleaning fluid 
so that the pump 118 can pump the cleaning fluid through spray tube 30 
into the coating compartment 32. In that embodiment, the drain hose 196 is 
likewise selectively switchable between a disposal tank and the reservoir 
20. Switching can be provided by the control system for automatic cleaning 
on a regular basis when the apparatus 10 is not in use if desired. 
Mounted in a fixed position on the head assembly 15 is a cam 178 which 
cooperates with a cam follower 180 to stop the head 15 in a position in 
which the flanges 104, the basket rails 142, and rollers 148 are aligned 
with support rails 56 to facilitate placement and removal of the basket 
16. The cam follower 180 is movable into contact with the cam 178 by means 
of an air cylinder 182. More specifically, air cylinder 182 is mounted to 
horizontal member 38 and to the cam follower 180 which moves along 
horizontal member 38 on guide rollers 186 and guide track 187 or 
equivalent means. The cam 178 has a single lobe 188. The cam follower 180 
has spaced cam follower rollers 190 mounted to come into contact with and 
arrest the cam 178 with the lobe 188 positioned between the cam follower 
rollers 190. 
The fluid control circuit 17 is shown in FIGS. 7 and 8. Individual 
regulators, valving and limit switches are not shown in the figures but 
would be used in the apparatus 10 of the invention as would be appropriate 
for particular applications of the apparatus 10. Compressed air is 
supplied by an input line 216, controlled by manual control valve 218 and 
relief valve 220. The pressurized air would typically be supp1ied by a 
central source or a separate air compressor. Exhaust lines 236, 238 are 
coupled to the fluid control circuit to permit the venting of air. 
Slide valves 222 are two position valves, which control air cylinders 172. 
Slide valves 224 are two position va1ves which control air cylinders 181. 
Slide valves 226 are three position valves which control air cylinders 
176. 
Slide valve 228 is a two position valve, which controls air cylinder 182. 
The air lines leading to air cylinder 182 contain adjustable flow 
regulators 184 to adjust the amount the "spring effect" that will be 
exerted by air cylinder 182 in actuating cam follower 180. 
Slide valve 230 is a three position valve, which is coupled to the air 
motor 12. Two postions of valve 230 provide for driving the air motor 12 
in forward and reverse directions. A neutral position of valve 230 is 
provided wherein the air motor 12 is stopped. The speed of the air motor 
12 is controlled by electrically actuated flow control valves 240. Slide 
valve 232 is a three position valve, which controls the air cylinder 210 
to raise and lower the coating tank 18. Slide valve 234 is a two position 
valve, which controls the air cylinder 94 to provide for raising and 
lowering of the spray tube 30. Slide valve 244 is an electrically actuated 
two position valve which controls the flow of coating to the spray tube 
30. In the embodiment of the invention in which a particular gas or 
combination of gases is used, the gas system 198 is controlled by an 
electrically actuated two position slide valve 242. 
The actuation of the electrically actuated valves 222, 224, 226, 228, 230, 
232, 234, 242, 244 in the fluid control circuit is performed by the 
electrical control circuit. It is convenient to use a programmed computer 
for the electrical control circuit. Many different types of computers or 
process controllers could be employed such as for example a Texas 
Instruments Model 510 or Modican 84 or General Electric Series 1. 
In operation, the parts that are to be coated are loaded into a basket 16 
while it is on support rails 56 in a shuttle portion 48 of the housing 11 
and the shuttle assembly 40 is in the outboard position. Loading may be 
done by hand or by a conveyor belt or other automatic means. The parts 
might typically range from relatively small parts such as nails and 
bushings to relatively large complex parts such as castings which require 
coating of interior and exterior surfaces. The basket 16 is displaced 
along the support rails 56 by the shuttle assembly 40 until the shuttle 
assembly 40 is in the inboard position and the basket rails 142 engage the 
flanges 104 of the basket mounting 70 and the basket 16 is centered on the 
basket mounting 70. The fingers 166 of the shuttle assembly 40 are then 
pivoted to disengage the shuttle assembly 40 from the basket 16. The 
shuttle assembly 40 is then moved to the standby position on the support 
rails 56. The coating tank 18 is then raised to enclose the basket 16 in 
the coating compartment 32. 
In an embodiment of the invention using a particular atmosphere, the gas 
system is actuated by means of valves 240 and 204 to supply the gas to the 
coating compartment 32. In a specific embodiment of the invention, while 
the gas is supplied the coating tank 18 is held below the tank ring 192 so 
that air is expelled through a gap between the coating tank 18 and the 
tank ring 192. In another embodiment of the invention a purging system 
withdraws the air. The spray tube 30 is then extended from its retracted 
position within the head 15 to the extended position in which the spray 
tube 30 extends into the basket 16 through the collar 146. 
The motor 12, head 15, and basket 16 are then rotated. The air motor 12 
spins first one direction and then the other. The length of time the 
basket 16 rotates before reversing is selected by means of the electrical 
control circuit, as required by particular applications. The adjustment 
may be made to less than a full revolution of the basket 16 between 
reversals of the motor 12. 
The pump 118 of the coating material system 31 is actuated when the 
apparatus 10 of the invention is started and is continally operated during 
the operation of the apparatus 10. Coating material is thus sprayed by the 
spray tube 30 by the actuation of valve 244. Like the rotation of the 
motor 12, the sequence, duration, and timing of spraying is controlled by 
the electrical control circuit. To coat a basket 16 of parts might for 
example, take roughly 90 seconds from start to finish with several 
spraying steps totalling 15 seconds. After the parts have been sprayed the 
basket 16 is stopped, to allow suspended coating material to settle. 
During the spraying, parts are coated by coating material propelled 
directly at the parts and by a fog of coating material build up in the 
coating compartment 32 during spraying. The perforate nature of the basket 
16 provides for ready circulation of this fog of coating material around 
the parts. 
Although the apparatus 10 of the invention permits the parts to be sprayed 
while static, generally the parts would be sprayed while in motion 
relative to the spray tube 30. This provides for greatly different angular 
velocities of the parts and of droplets of coating material. This results 
in droplets impacting the parts obliquely, and each droplet painting a 
larger area with a thinner coating. 
After the parts have been sprayed with the coating material the parts are 
spun to remove excess coating material, which returns to the reservoir 20. 
After completion of the spinning, the rotation of the motor 12 is slowed 
and the cam follower 234 is extended into the path of the rotating cam 230 
so as to stop the rotating head 15 and basket 16 in a position in which 
the basket handle 154 is disposed toward the direction of the shuttle 
portion 48 of the housing 11 which is not already occupied by the other 
basket 16. The shuttle assembly 40, adjacent the basket handle 154 of the 
basket 16, is then moved by its air cylinder 176 from a standby position 
to an inboard position. The basket 16 is then engaged by the fingers 166 
of that shuttle assembly 40 and the shuttle assembly 40 then moves the 
basket 16 onto the support rails 56 and out of the main portion 36 of the 
housing 11 and into that shuttle assembly's 40 respective shuttle portion 
48 of the housing 11. The unloader arm 179 is then moved into engagement 
with the basket handle 154 and the basket handle 154 is moved pivoting the 
base plate 150 of the basket 16 discharging the parts onto tables or a 
conveyor belt. The movement of the unloader arm 179 can be repeated, if 
the user so selects, to ensure that all parts have been discharged. The 
unloader arm 179 then returns to its original position as does the bottom 
plate 150 of the basket 16. The bottom plate 150 does so because of its 
weight, or in the alternative a biasing means can be used. The basket 16 
may then be again loaded. 
The baskets 16 operate alternatively with each other and as one basket 16 
is moved out of the main portion of the housing 11 for unloading another 
is moved in for spraying. 
All electrical connections within the apparatus 10 of the invention are 
explosion-proof, as they are sealed in conduit or are within the control 
panel 13. However, for use of flammable coating, ventilation ductwork 
could be added to the apparatus 10 of the invention to protect the user. 
Coating materials that may be applied include but are not limited to: 
acrylics, epoxies, adhesives, lacquers, lubricants, phenolics, 
Teflon.RTM., varnishes, paints, and other water based and solvent based 
coatings. 
The method of the invention is in its broadest form, in summary, loading 
parts into a basket generally perforate to the coating material, 
detachably coupling the basket to a rotatable head, separably enclosing 
the basket in a coating compartment generally imperforate to the coating 
material, supplying coating material to a spray tube from a coating 
material system, spraying said coating material from said spray tube onto 
said parts while the basket is enclosed in the coating compartment, 
agitating the parts by rotatably moving the basket and head while the 
basket is in the coating compartment, separating the basket from the 
coating compartment and unloading the basket. 
The parts are agitated by rotating the basket first in one direction and 
then in the other. The change in direction of rotation is rapid and the 
basket rapidly accelerates up to speed again after the direct of rotation 
is changed. The change in direction and acceleration of rotation tumbles 
the parts. The basket need not be rotated an entire revolution in each 
direction before the direction of rotation is changed but need only be 
oscillated back and forth through partial revolutions if desired. 
While the basket is in the coating compartment the parts are sprayed with 
the coating material. The spraying may alternate or be simultaneous with 
agitating the parts. For example, the parts may be sprayed as they are 
tumbled. The parts tumble in directions that are generally tangential to 
the directions of rotation of the basket. In a specific embodiment the 
basket includes a core which directs the tumbling of the parts in a radial 
direction in addition to the tangential one. 
After the parts are sprayed and agitated in accordance with a selected 
sequence, duration, and timing of those operations programmed into the 
electrical control circuit, excess coating material is removed from the 
parts, by spinning the basket. The excess coating material is recycled to 
the coating material system for reuse. 
Specific embodiments of the method of the invention inc1ude pumping the 
excess coating material to a reservoir of the coating material system to 
recycle it and filtering the excess coating material while recycling it. 
In one embodiment of the method of the invention the spraying and agitating 
steps are performed under an atmosphere determined by the requirements of 
a particular coating material, for example, some coatings require use of a 
non-oxidizing atmosphere, and argon or helium or another inert gas could 
be used. 
In a specific embodiment of the method the atmosphere the spraying and 
agitating steps are performed under is pressurized to more or less than 
atmospheric pressure. 
While a specific embodiment of the invention has been shown and described 
herein for purposes of illustration only, it is desired that the 
protection afforded by any patent which may issue upon this application 
not be limited strictly to the disclosed embodiment; but that it extend to 
all structures and arrangements which contain the essence of the invention 
and which fall fairly within the scope of the claims which are appended 
hereto.