Note: Descriptions are shown in the official language in which they were submitted.
23'7
TITLE
Computerized Spray Machine
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
the present invention is related generally
, to paint spraying machines, especially those utilized
to prepare panels that can be used as paint
standards. More particularly, the invention relates
to a spray machine that is controlled automatically
by a computer system that allows diverse spray
procedures to be quickly and easily selected.
DESCRIPTION OF RELATED ART
Automated paint spraying systems are
well-known for use along assembly lines. As an
example, see US Patent No. 3,989,003 ('003), issued
November 2, 1976 to Sagan and Mania. '003 discloses
a system comprising conveyor means that carry an
- object by a spray gun, that is controlled by memory
means that have been programmed with data relating to
I-- 20 object style and object position relative to the
spray gun. US. Patent No. 3,739,742 ~'742), issued
- June 19, 1973 to Razz and Higgins, has similar
disclosure.
Spray machines also are well-known in the
paint industry, for use in preparing painted panels.
Certain panels serve as standards. Other panels are
then compared against the standards, and if there is
a color or other quality discrepancy, the batch of
paint with which the panel was sprayed is modified
accordingly.
A typical spray machine uses a spray gun
with drive means that are capable of being set to
control horizontal and vertical movement of the gun,
as well as speed of the gun. Other variables of the
spray machine capable of being set include the number
,:
I
of passes of the gun (related to paint fan spray
pattern of the gun), the flash period after each coat
(to allow solvent evaporation), the width of the
spray stroke, the number of coats of paint and the
like.
Any particular paint will have unique spray
characteristics and the spray machine must be set
accordingly so thaw spray times, gun traverse
velocity, flash interval times, vertical panel
indexing and the like are compatible with the paint
being sprayed. Prior to the present invention, such
variables were set manually, which required extensive
time. Once 2 machine was set for a particular paint,
it was dedicated to be used only with that paint and
not used for other paints because of the lengthy time
required to readjust the machine. However, with the
computer controlled spray machine of the present
invention, a single spray machine can easily and
quickly be adjusted to spray all types of paint.
SUMMARY OF THE INVENTION
The present invention provides for an
improved paint spray machine of the type comprising
at least one spray gun with an adjustable spray
nozzle, means for controlling the speed and
acceleration of the horizontal and vertical movement
of the gun, means for controlling the number of
passes by the gun, means for controlling the dwell
period at the end of each pass and means for
controlling flash time between coats of paint;
wherein the improvement comprises a computer system:
a. capable of storing programs for
multiple spray procedures with their
specific operating parameters; and also
b. capable of actuating, monitoring
and, if necessary, correcting parameters of
a spray procedure so as to insure accurate
spray application.
S BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a schematic representation
illustrating the major components of a spray machine
incorporating the present invention.
Figure 2 is a more detailed schematic
representation of the computer system as it relates
to the spray gun and the drive controls of the spray
gun
Figure 3 is a more detailed representation
of the spray gun and the drive controls of the spray
gun.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a keyboard 1, typically
a RCA VP 611* with a display means, typically an IRE
Crop permutes a microcomputer 2, typically
an Intel SAC 80/10~ to be programmed to store various
paint spraying procedures. Both the keyboard 1 and
the microcomputer 2 are electrically powered through
safety barriers (not shown) such as a Stahl Model No.
8901/31/280/165/8~. These safety barriers allow the
I spray machine to be used in an area containing
explosive solvent fumes, also called a classified
environment as defined in The National Electrical
Code Article 500. The electrical items used in the
spray machine that do not utilize a safety barrier
are either purged with air, i.e., under a positive
air pressure or within explosion proof containers as
required by The National Electrical Code.
In operation of the spray machine, referring
to FIG. 1, the keyboard with display means 1 permits
a microcomputer 2 to be programmed to store various
*denotes trade mark
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spray procedures. The microcomputer 2 provides
feedback to an operator utilizing the spray machine,
via the keyboard with display means 1. The
microcomputer 2 communicates in English with the
operator via the display means portion of the
keyboard. By communicating with the operator, the
microcomputer 2 helps the operator properly prepare a
spray procedure program. The microcomputer 2
identifies the paint spray parameters that must be
set and will reject invalid, i.e., out-of-range, data
regarding any spray procedure parameters. It is
possible for an operator to prepare a spray procedure
- program by entering on the keyboard, actual operating
units (e.g., inches/minutes, seconds, inches, etc.).
The microcomputer 2 is connected to
interface 3, typically a Model No. SKYE swerve
controller made by Industrial Indexing Systems, Inch
Interface 3 converts an electronic signal from the
microcomputer 2 to a signal which is fed to the spray
gun drivers/controller 4 which contains the motors
for the horizontal and vertical motion of the spray
gun or guns 5 shown spraying a panel 7.
j Typically, interface 3 contains numerous
solid state driver relays such as Ought Co. Model
OKAY for on-off control air solenoids and sensing
devices such as Model IAC5*that determine for
example, the position of the panel being sprayed and
monitor purging system status of the electrical-
j components and the like.
Optionally, in addition to the microcomputer
2 a remote computer 6 can be utilized. This remote
computer would function in the same manner as the
' - keyboard with display 1, i.e., the computer would
j feed in a program or spray parameters for a certain
35 paint being tested. The advantage of a remote
*denotes trade mark
So
computer 6 is that a spray machine may then be part
of a central spray procedure control network, allowing
the network center to program or deprogram remote
machines via a phone line modem connection 10. Typically,
new spray procedures developed or modified can be trays-
milted from a central laboratory to paint manufacturing
plants via the phone line modem connection.
Referring now to FIG. 2, an operator,
desiring to utilize a particular spray procedure
already programmed into the microcomputer 2 would enter
the spray procedure program identification code on the
alpha-numeric keyboard lay The identification code is
inputted by the microcomputer 2 which then interrogates
its memories pa and 8b to find therein the procedure
corresponding to the identification code. A typical
nonvolatile read/write memory pa is an Ampex MOM 8080~
16k core stack and a typical read only memory 8b is an
Intel SBC464* with 2716* memory chips. If the procedure
is nonexistent, an error message is communicated to the
operator via the display means lb. If the procedure
is present, the microcomputer 2 outputs to the alpha-
numeric misplay means lb a message that the machine is
ready for operation.
The operator depresses a START CYCLE button,
now shown, on the keyboard lo which activates the
microcomputer 2 and starts a spray procedure. The
microcomputer 2 through the interface 3, activates
the vertical motion means pa and horizontal motion
means 4b both being par of the spray gun drive and
control units 4, FIG 1). The spray gun 5 controlled
by spray gun controller 9 connected to interface 3
automatically sprays paint on positioned panel 7.
The microcomputer 2 also monitors the drive and
*denotes trade mark
,,, .
5 I
control units 4 and, if necessary, will correct for
any discrepancy between the operational parameters as
programmed and as actually being carried out.
Vertical motion means pa and horizontal
motion means 4b utilize servo motors to drive the
spray gun, typically an Inland motor Kollmorgen Corp.
Model No. TT2952C* and contain a motor amplifier
SPARKS*. The motors are modified to meet the
specifications of Art. 500 of The National Electrical
Code for operation within classified environments
An operator can, in addition to calling up
spray procedures already programmed into the
microcomputer 2, insert new spray procedure programs
into the nonvolatile read/write memory pa of the
microcomputer 2. To do so, the operator assigns to
the new program an identification code, via the
keyboard lay The microcomputer 2 verify that the
code chosen is unique, and if the code is unique, the
microcomputer 2 will then request from the operator,
via the display means lb, information regarding the
various parameters of the new procedure. The
interface 3 converts the computer signals into
signals compatible with the horizontal and vertical
motion drive means pa and 4b.
I 3 shows preferred embodiments for
horizontal and vertical motion means driving spray
gun 5 which is shown spraying panel 7. The
horizontal motion means consist of a screw drive
servo motor 11 that is capable of driving a mast 12
via screw 13, to which the spray gun 5 is attached
¦ along a horizontal way 14. The screw drive servo
motor 11 is equipped with feedback encoders (not
I shown) capable of supplying the microcomputer 2 with
data regarding horizontal motion acceleration,
velocity and position of the spray gun 5.
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:~ZSZ3~7
The vertical motion means of FIG. 3 consist
of a vertical screw servo motor 15 that is capable of
turning a screw 16 to which the spray gun 5 is
attached. The screw servo motor 15 is also equipped
with feedback encoder (not shown) capable of
supplying the microcomputer 2 with data regarding
vertical motion acceleration, velocity and position
of the spray gun 5.
Paints can have different viscosities which
directly affect the flow of the paint through a spray
gun. Temperature also affects paint viscosity and
hence, paint flow. To provide identical spraying
conditions for paints being tested, it is desirable
to accurately control the flow of paint to the spray
gun. This can be accomplished with minor additions
of equipment to the spray machine.
To monitor the flow of paint r a flow meter
is positioned in the paint supply line which is
connected to the spray gun and a conventional
pressure vessel containing paint. In normal
operation of a spray machine, paint is supplied from
the pressure vessel to the spray gun. The flow meter
is electrically connected to the computer and feeds
paint flow information into the computer. The flow
meter is a turbine type having a magnetic pick-up and
a pulse frequency output signal proportional to the
speed which the turbine is rotating which is
proportional to the paint flow. The signal is fed to
a readout attached to the flow meter which converts
the signal to units that are proportional to paint
flow and are fed directly to the computer.
Typically, a model MF30 Flow meter Transducer*
manufactured my Holler Flow Meter Controls Inc. with
an associated readout is used.
*denotes trade mark
:~22S~37
A controller unit to control the air
supply winch pressurizes the paint in the pressure
vessel is electrically connected to the computer.
The controller unit is an automatic pressure regulator,
typically a Fairchild 1210B~X-3.5 SFM-2-lCl-80331~
Motorized Pressure Regulator. The motorized regulator
is connected to the computer via solid state drivers
which convert the digital output signals from the
computer to the modulated air pressure within the paint
pressure vessel. The automatic valve throttles the air
pressure supplied to it at about 90 pounds per square
inch (psi) and controls the air pressure to the vessel
at about 0-15 psi.
In a typical paint spraying operation, the
flow meter monitors paint flow. If the paint flow is
below a desired amount, the computer automatically
signals the controller units to provide additional air
- pressure to increase the paint flow. If the flow rate
is higher than desired, the computer signals the con-
troller units to lower the air pressure which de-
creases paint flow.
One of the advantages of the computerized
spray machine is that each coat of paint applied to a
panel can be applied using different spraying
parameters. For example, different spray times,
flash times, dwell times, and different horizontal
and vertical application speeds can be used for each
coat of paint applied. This is not practical with a
conventional mechanical spray machine.
*denotes trade mark
