U.S. patent number 3,924,810 [Application Number 05/520,759] was granted by the patent office on 1975-12-09 for sprayable material changer apparatus.
This patent grant is currently assigned to Ford Motor Company. Invention is credited to Charles H. Otterstetter.
United States Patent |
3,924,810 |
Otterstetter |
December 9, 1975 |
Sprayable material changer apparatus
Abstract
Apparatus is disclosed for communicating a plurality of
fluidized sources with a spray apparatus. A plurality of sources
are communicated to individual ones of a plurality of ports
extending through a stationary plate member. A rotary and
longitudinally displaceable plate member is arranged in alignment
with the stationary plate member and is provided with a single
orifice which communicates with the spray apparatus. The rotary
plate is further provided with means forming a sealing member which
are arranged to cooperate with gasket means provided for each of
the source orifices on the stationary plate member so as to
sealingly close the nonselected orifices and to provide for
contamination free communication between the selected source
orifice and the single orifice on the rotary plate member.
Inventors: |
Otterstetter; Charles H.
(Southgate, MI) |
Assignee: |
Ford Motor Company (Dearborn,
MI)
|
Family
ID: |
24073944 |
Appl.
No.: |
05/520,759 |
Filed: |
November 4, 1974 |
Current U.S.
Class: |
239/305 |
Current CPC
Class: |
B05B
7/1404 (20130101); B05B 7/1472 (20130101); B05B
12/149 (20130101); B05B 5/1683 (20130101); B05B
7/1477 (20130101) |
Current International
Class: |
B05B
5/00 (20060101); B05B 5/16 (20060101); B05B
7/14 (20060101); A62C 031/00 () |
Field of
Search: |
;239/112,15,596,305 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: King; Lloyd L.
Attorney, Agent or Firm: Benziger; Robert A. Zerschling;
Keith L.
Claims
I claim:
1. Apparatus for communicating a powder spray gun with a plurality
of fluidized powder sources while avoiding cross contamination of
powders comprising in combination:
a stationary plate member having a powder side and a sealing side,
a plurality of powder passages and at least one flushing passage,
said passages extending through said plate from the powder side to
the sealing side;
hose means coupled to said powder passages on the powder side of
said plate for fluid-tight communication of said powder passages
with the plurality of powder sources;
further hose means coupled to said at least one flushing passage on
the powder side of said plate;
means coupled to said further hose means for flowing a flushing
medium therethrough;
plate valve means supported in closely spaced relation to said
stationary plate member and having a flow passage means extending
through said plate valve means and aligned for fluid communcation
with said powder passage and said at least one flushing
passage;
hose means coupled to said flow passage means for communicating
said flow passage means with the spray gun;
means connected to said valve plate means for varying the spatial
relation between said valve plate means and said stationary plate
member;
indexing means operative to align said flow passage with a selected
one of said powder and flushing passages;
seal means interposed between said stationary plate member and said
valve plate means operative to provide sealed communication between
said flow passage and said selected one of said powder and flushing
passages;
said plate valve means comprising a plate member mounted for
rotation about an axis, said rotation axis being arranged to extend
through the stationary plate member, and said spatial relation
varying means comprise cylinder means interconnecting said
stationary plate member and said plate valve means actuable to
increase the spatial relation to a first predetermined amount and
to decrease the spatial relation to a second predetermined amount;
and
said indexing means comprising step motor means operative when the
spatial relation between the stationary plate member and the valve
plate means is at the first predetermined amount to rotate said
valve plate means about said axis until said flow passages is
aligned with the selected one of the powder and flushing passages
and to actuate said piston means to establish a spatial relation of
the second predetermined amount.
2. The apparatus of claim 1 including control means to
automatically and sequentially operate the piston means and the
indexing means to communicate different selected ones of the powder
passages with the flow passage and to communicate the flow passage
with the flushing passage between successive different powder
passage communications.
3. Apparatus for communicating a powder spray gun with a plurality
of fluidized powder cources while avoiding cross contamination of
powders comprising in combination:
a stationary plate member having a powder side and a sealing side,
a plurality of powder passages and at least one flushing passage,
said passages extending through said plate from the powder side to
the sealing side;
hose means coupled to said powder passages on the powder side of
said plate for fluid-tight communication of said powder passages
with the plurality of powder sources;
further hose means coupled to said at least one flushing passage on
the powder side of said plate;
means coupled to said further hose means for flowing a flushing
medium therethrough;
plate valve means supported in closely spaced relation to said
stationary plate member and having a flow passage means extending
through said plate valve means and aligned for fluid communication
with said powder passages and said at least one flushing
passage;
hose means coupled to said flow passage means for communicating
said flow passage means with the spray gun;
means connected to said valve plate means for varying the spatial
relation between said valve plate means and said stationary plate
member;
indexing means operative to align said flow passage with a selected
one of said powder and flushing passages;
seal means interposed between said stationary plate member and said
valve plate means operative to provide sealed communication between
said flow passage and said selected one of said powder and flushing
passages; and
seal means interposed between said stationary plate member and said
plate valve means operative to seal closed the nonselected ones of
the powder and flushing passages;
said seal means comprising
a. a plurality of first seal element means situated on said
stationary plate member in proximity to the sealing side thereof
and arranged to be in surrounding relation to the sealing side
orifice of each of the powder and flushing passages and
b. means defining second seal element means positioned on said
plate valve member in juxtaposed relation to the plurality of first
seal element means, the second seal element means including a
passage means aligned with the flow passage means of the plate
valve means to provide unrestricted material flow through from a
selected one of the powder and flushing passages to said flow
passage means.
4. The apparatus of claim 3 including further a plurality of check
valve means situated in the powder passages and having orifices
extending from the seal side of the stationary plate member toward
the valve plate means, and valve operating means extending from the
flow passage, operative to engage and open the check valve means
situated in the selected one of the powder and flushing
passages.
5. The apparatus of claim 4 wherein each of said check valve means
comprise displaceable ball valve member, means resiliently biasing
said ball valve member toward a valve seat and said valve operating
means comprise a projecting finger element situated in the flow
passage means of said plate valve means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of spray apparatus in
general and more particularly to that portion of the above-noted
field which is concerned with the spraying of material such as for
coatings. The present invention is more particularly directed to
that portion of the above-noted field wherein a plurality of
materials must be intermittently sprayed in a random sequence
fashion and wherein it is highly desirable to avoid any cross
contamination of the material. More particularly still, the present
invention is directed to apparatus for use in association with an
electrostatic powder spray apparatus for providing that powder
spray apparatus with communication to a plurality of dry powder
sources in a manner which will allow rapid change of powder
communication from a first selected powder to a second selected
powder and which will avoid any cross contamination of the powder
being sprayed with residue from a previous spray operation.
2. Description of the Prior Art
In the spraying of dry powder materials such as film forming
coatings on, for example, automotive body panels, it is frequently
necessary to have a single spray station spray a different powder
coating on each of a succession of body panels. A single spray
station may have one or more spray apparatus, typically referred to
as spray guns, arranged to spray the material in unison. In order
to maintain the speed of the spray assembly operation at a smooth
and economically rapid level, it is necessary that the spray
apparatus be capable of changing from one sprayable material to
another sprayable material in approximately the same amount of time
as that required for the successive body panel to come into the
range of the spray apparatus. It is therefore a general objective
of the present invention to provide a means for changing the
material being supplied to a spray station in the time period
required for successive parts to enter the spray station.
One way in which this objective may be obtained is to provide each
spray material with separate spray apparatus and to automatically
change between successive spray apparatus for each successive body
panel. However, this is an expensive and awkward solution to the
problem in view of the fact that powder coating materials are
normally sprayed with an electrostatic charge to facilitate uniform
deposition of the uniform coating and the provision of a plurality
of spray apparatus would necessitate the provision of a plurality
of electrostatic charging devices. Such a solution would also be
cumbersome in the sheer bulk of equipment required to be maintained
at any one spray station. Furthermore, a safety hazard would be
introduced by the additional machinery required to switch between
successive spray apparatus and by the necessity of maintaining a
large number of electrostatically charged pieces of spray
apparatus. It is therefore an object of the present invention to
provide a changer for spray apparatus which may intercommunicate a
single spray apparatus with a plurality of sprayable material
sources.
One mechanism which has been successfully used in the past to
achieve the aforementioned objective has been to provide a
plurality of powder manifolds each having a spray channel and a
powder channel. The manifolds are interconnected to align the spray
channel so as to provide a common passage through the manifold.
Each powder channel intersects the spray or common passage and
communicate with a single material source. Such an apparatus is
thereafter controlled by sequential valving situated in the powder
channel upstream from the junction of that channel with the spray
passage. This valving may open individual powder channels and will
concomittently close all other powder channels to prevent any cross
contamination. However, such valving apparatus, situated as it must
be within the powder channels slightly upstream from the junction
of the respective powder channel with the spray channel, provides a
small pocket area where residue spray material may accumulate.
While it is normally the custom to provide for a flushing operation
of the spray channel and of the spray apparatus between successive
applications of material by the spray apparatus, the pockets of
accumulated spray material are difficult to thoroughly flush and
frequently result in contamination of the material being sprayed by
a residue of material from a previous spray operation. It is
therefore a further and specific object of the present invention to
provide a material changer apparatus for use in conjunction with a
spray apparatus which may intercommunicate the spray apparatus with
a plurality of sprayable material sources and which will prevent
any cross contamination of the sprayable material. More
specifically, it is an object of the present invention to provide
such apparatus which will avoid the formation of accumulation
regions downstream from the control valving to thereby avoid the
formation of residue of sprayable material.
Still another attempt to solve the above noted problem has been to
provide the spray apparatus with a plurality of material supply
conduits. The supply conduits are arranged to have each of their
exhaust ports aimed or focused to deliver streams of material to be
sprayed to the center of a vortex nozzle. This a single material
may be supplied from a selected supply conduit and may be sprayed
by the apparatus. The spray nozzle may be subsequently communicated
to a different supply. This arrangement is size limited in that
only a small number of conduits may be arranged to be focussed
toward the center of the vortex and is further complicated by the
fact that the vortex aiming is critical. It is therefore a further
and specific object of the present invention to provide material
changer apparatus for a spray apparatus which may communicate that
spray apparatus with a large plurality of sprayable material
sources or reservoirs. It is a still further and particular object
of the present invention to provide such an apparatus in which
placement of the means for communicating the changer apparatus with
the material reservoirs may be noncritical in use. It is a still
further object of the present invention to provide such apparatus
which may automatically change the communication of the spray
apparatus from a first selected material reservoir to a second
selected material reservoir while providing an intermediate
flushing action. More particularly still, it is an object of the
present invention to provide a changer apparatus which may
intercommunicate a plurality of fluidized dry powder sources with
an electrostatic spray apparatus which is inexpensive and reliable
and which avoids cross contamination of sprayed powders. Other and
further objects of the present invention will be apparent from the
description which follows and the claims which are appended.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a valving mechanism comprised of a
pair of relatively movable plate members. One plate member is
arranged to be stationary and the other plate member is arranged
for rotary and translatory movement. The stationary plate member is
provided with a plurality of passages extending therethrough, one
of which may be communicated to a source of flushing fluid and the
remainder of which may be communicated to a plurality of reservoirs
of sprayable material. The movable plate member is provided with a
single passage means which may be arranged to communicate with the
spray apparatus on the one side and, through suitable translatory
and rotary movement of the plate, with selected ones of the
stationary plate passages. Each of the stationary plate member
passages may be provided with means defining a gasket seat or ridge
surrounding the orifice thereof while the rotary plate member may
be provided with means defining sealing structure to cooperate with
the gasket seat or ridge provided on the stationary plate member to
provide for sealing of each of the stationary plate member passages
when the plate members are closely proximate to each other.
In order to achieve the desired translatory movement of the movable
plate member, a double acting piston and cylinder means is provided
interconnecting the stationary and movable plate members which may
be rendered operative to translate the movable plate member toward
and away from the stationary plate member. In order to accomplish
the desired rotational movement of the movable plate member, a
stepping motor means may be provided to rotate the movable plate
member clockwise and counterclockwise about an axis so as to align
the movable plate member passage means with selected ones of the
stationary plate member passage means.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a side sectional view of the changer apparatus
according to the present invention.
FIG. 2 illustrates an end view of the apparatus of FIG. 1.
FIG. 3 illustrates in a schematic diagram form the present
invention as applied to an electrostatic powder coating spray
operation.
FIG. 4 illustrates a block diagram for one form of a control system
for controlling the material changer apparatus according to the
present invention and useful in a system according to FIG. 3.
FIG. 5 illustrates an alternate embodiment of the valve sealing for
the changer according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, FIG. 1 illustrates the material
changer apparatus 10 according to the present invention. For
purposes of illustration, the present invention will be described
hereinbelow with reference to the application of various color
fluidized powder film forming materials by electrostatic spray
deposition methods to automotive vehicle body panels. It will be
appreciated that the present invention is applicable to spray
apparatus other electrostatic spray apparatus and with sprayable
materials other than dry powder film-forming coating material.
Powder changer apparatus 10 is comprised of a stationary plate
member 12 and a movable plate member 14 which is supported for
rotation about axis 16. Plate member 12 has a powder supply side 18
and a sealing surface side 20. Plate member 12 is provided with a
plurality of passages 22 which extend therethrough from the powder
supply side 18 to the sealing surface side 20. Each of the passages
22 may be communicated, for example, by means of hoses 24 with a
source of fluidized powder and by means of hose 26 with a source of
a flushing agent as will be described hereinbelow.
Stationary plate member 12 is connected to the movable plate member
14 by cylinder means 28 which is illustrated as being attached to
the powder supply side 18 of the stationary member 12. Cylinder
means 28 includes a double acting piston member 30 situated within
the cylinder cavity 32. Piston 30 is arranged for reciprocating
movement within cylinder means 28 and is provided with stub shaft
member 34 which extends through the stationary member 12 and is
fixedly attached to movable plate member 14. It will be appreciated
that stub shaft member 34 should be provided with some form of
pressure retaining sealing between it and stationary plate member
12. Piston member 30 is arranged to be actuated in the first
direction by fluid pressure provided to cylinder cavity 32 through
fluid conduit 36 and is arranged to be actuated in a second or
opposite direction by fluid pressure provided to cylinder cavity 32
through fluid conduit 38. Piston 30 is further provided with a pair
of seal members 40 which operate to seal each end of the piston 30.
As illustrated, seal members 40 may be, for example, flexible
O-rings or such other seal means as are convenient.
The application of fluid pressure through fluid conduit 36 and
fluid passage 42 to face 46 of piston 30 is operative to displace
piston 30 rightward relative to FIG. 1, and through its connection
to the movable plate member 14 by stub shaft 34, to cause movable
plate member 14 to translate rightwards. The application of fluid
pressure through fluid conduit 38 and fluid passage 44 to the right
hand face 48 of piston 30, relative to FIG. 1, will be operative to
cause piston 30 to translate leftward relative to the figure. Due
to the interconnection of piston 30, stub shaft 34 and movable
plate member 14, leftward movement of piston 30 will cause the
movable plate member 14 to also translate leftward.
Each of the material supply hoses 24 and the flushing material
supply hose 26 is arranged to extend through stationary plate
member 12 from the supply side 18 to the sealing surface side 20.
The hoses 24, 26 are terminated in an extending flange portion 50
which generally surrounds the passages 22 of the stationary plate
member 12. Each flange portion 50 is provided with a gasket seat or
ridge 52 which may be, for example, a ridge portion formed as a
part of the flange portion 50. Ridge 52 may alsso be a separately
embedded member or annulus of suitable material such as metal.
Movable plate member 14 is provided with means defining a single
fluid passage 54 which communicates on the one side with spray
apparatus supply hose 56 and is arranged to communicate on the
other side with a similarly provided passage 58 which extends
through cooperating seal element 60. In a preferred embodiment,
cooperating seal element 60 is an annular band of natural rubber
material which extends around the periphery of the inner side of
movable plate member 14. Cooperating seal element 60 is provided
with a single passage 58 and is therefore operative, when movable
plate member 14 is in the extreme leftward position relative to
FIG. 1, to cooperate with the gasket seats or ridges 52, and the
flange portions 50, of each of the hoses 24, 26 to seal the hoses
from the environment. In the case of the selected, here illustrated
as hose 26, which is in fluid communication with spray apparatus
supply hose 56, the sealing action of cooperating seal element 60
and gasket seat or ridge 52 will be to provide for fluid tight
communication from the selected one hose 24 and the spray apparatus
supply hose 56.
A second stub shaft 62 is attached to piston 30 so as to extend
away from face 46 of piston 30. This stub shaft 62 extends through
cylinder 28 and may be connected, for example, by a sliding spline
connection, to a stepping motor 64. When energized, stepping motor
64 may be arranged to rotate stub shaft 62, piston 30, stub shaft
34, and movable plate member 14. Thus, when fluid pressure is
applied to the face 46 of piston 30 and piston 30 has been
displaced rightward so as to displace movable plate member 14
rightward with respect to stationary plate member 12, energization
of stepping motor 64 will be operative to rotatably displace
movable plate member 14 with respect to stationary plate member 12.
By arranging the spacing of the steps of the step motor 64 in any
of the well known ways, the single passage means 54 of the movable
plate member 14 may be aligned with selected ones of the passages
22 so as to permit, upon leftward displacement of the piston 30,
direct communication between the spray apparatus supply hose 56 and
the selected one of the material supply hoses 24, 26.
With reference now to FIGS. 1 and 2 it can be seen that passage
means 54 of the movable plate member 14 and the passages 22 of the
stationary plate member 12 are arranged to be equidistantly spaced
from the axis 16. Furthermore, passages 22 may be arranged to be
angularly equidistantly spaced about the periphery of stationary
plate member 12. As illustrated in FIG. 2, there are six passages
22 arranged about the stationary plate member 12. It will be
appreciated that the number of passages 22 is dependent only on the
size of the passages 22 and the size of stationary plate member 12.
It can also be seen that the stationary and movable plate members
12, 14 preferably are of circular configuration. It will be
appreciated that, while reference is made herein to the passages 22
as being individual passages and passage 54 has been referred to as
a single passage, passage 54 could be a plurality of passages in
any desired configuration, each of which could be communicated to
one of a plurality of spray apparatus supply hoses. The passages 22
of stationary member 12 could be similarly arranged and configured
and could communicate with a plurality of hoses 24, 26 each of
which would then communicate with a reservoir of sprayable
material. The advantage of this arrangement would be to permit the
supply of a single sprayable material to a plurality of spray
nozzles as may be used for example to apply coatings to a large
surface area when a single spray apparatus would not have
sufficient delivery capability.
Referring now to FIG. 3, the changer apparatus 10 according to the
present invention is illustrated as applied to a powder paint spray
apparatus operation utilizing an electrostatically charged powder
spray apparatus 66. Powder spray apparatus 66 is electrostatically
charged from electrostatic charging means 68 through conductors 70.
Electrostatic charging apparatus 68 is illustrated as being
energized from a conventional AC electrical source through electric
line cord 72. Electrostatic powder spray apparatus 66 is operative
to provide a spray of electrostatically charged powder coating
material to the surface of a member to be coated, shown as 74. As
is well known, the powder paint material will be uniformly
distributed and will adhere to member 74 through the action of the
electrostatic charge. In the spray coating of automobile bodies,
for example, as discussed hereinabove it is frequently necessary
that successive spray applications of material to successive body
panels be of differing colors. In order to facilitate a rapid and
contamination-free change of the powder being provided to the
powder spray apparatus, the changer of the present invention is
arranged to communicate with a plurality of reservoirs of fluidized
powder coating material through a plurality of connecting hoses 24.
For example, FIG. 3 illustrates a pair of connecting hoses 24 being
communicated to reservoirs 76, 78 each of which contains a
fluidized bed of powder material of differing colors and a
venturi-type powder pump 80, 82. A pneumatic fluid line 90 extends
from the control system 84 to each of the powder pumps 80, 82 for
providing an energizing fluid flow for the selected material. In
addition, hose 26 may be communicated to a source of flushing
agent. One convenient flushing agent is shop air which may be used
to purge the hoses and passages downstream from the changer
apparatus between successive applications of powder coating
material.
In operation, the present invention functions as follows. A
flushing agent such as shop air is communicated through hose 26 and
through the appropriate passages of the changer apparatus 10 to the
spray apparatus supply hose 56 and the spray apparatus 66. After a
sufficient period of time has elapsed to assure that all residue
powders have been exhausted from the spray apparatus supply passage
56 and from the spray apparatus 66, the control system 84 will
command the application of fluid pressure, which may also be shop
air, to fluid conduit 36 and the face 46 of piston 30 to cause
movable plate member 14 to translate rightward, relative to FIGS. 1
and 3, away from the stationary plate member 12. Proximity sensor
switch 86 will respond to plate 14 reaching the extreme rightward
position so that stepping motor 64 may be actuated to rotatably
displace movable plate member 14. Step motor 64 may be arranged to
rotate clockwise and/or counterclockwise a predetermined angular
distance to align passage 54 with a selected one of the passages 22
so that upon application of fluid pressure to passage 38 and face
48 of piston 30 and leftward displacement of rotatably plate member
14, the spray apparatus supply hose 56 will be placed in fluid
communication with the selected one of the powder hoses 24 and its
associated material reservoir so that the application of the
appropriate powder coating material to the next successive body
panel 74 may be achieved. Upon leftward displacement of movable
plate member 14, proximity sensor switch 86 will inform the control
system 84 that leftward displacement has been achieved and the
material reservoir powder pump for the selected material may be
energized. Due to the dual sealing action of the inter-plate
sealing means 50, 60 powder supplied from the one selected powder
reservoir 76, 78 which communicates directly with the spray
apparatus supply hose 56 will be prevented from entering and
accumulating in the passages 22 which communicate with the
nonselected reservoirs. After the passage of an amount of time
selected to correspond with the rate of travel of the body panel 74
on the conveyor apparatus past the nozzle 88 of spray apparatus 66,
the control system 84 will depressurize the powder pump in the
reservoir of the selected material and the movable plate member 14
will be automatically indexed to place the spray apparatus supply
hose 56 in communication with the flushing agent supply hose 26 so
that residue powders may be exhausted from supply hose 56 and from
the spray apparatus 66. In the preferred embodiment, the flushing
agent may be pressurized shop air but alternatively, the spray
apparatus 66 and supply hose 56 may be flushed by a vacuum
operation in which the powders which act as residue within the
spray apparatus and the spray apparatus supply hose may be
collected and returned to the respective fluid supply reservoirs
76, 78.
Referring now to FIG. 4, a representative control system 84 for
controlling the sequence of operation of the changer apparatus 10
according to the present invention is illustrated. In the
illustrated control system, the principal element of the control is
the memory and electrical sequence signaller 90 which may be, for
example, an Edon Memo-Chain control mechanism having memory
capability. This central processing unit 90 receives material
selection indications from the powder selectro 92 and applies
suitable control signals to the pneumatic control means 94. Unit 90
also applies suitable electrical signals to indexer 64 to
accomplish clockwise or counterclockwise stepping motion when
switching from one of the selected passages 22 of stationary plate
member 12, to the flushing position, and to a second selected
passage 22 of the stationary plate member 12. Pneumatic control
means 94 receives pneumatic fluid, which may also be shop air,
under pressure from pneumatic source 96. Pneumatic control means 94
may be comprised, for example, of suitable electromechanical valve
means for controlling the application of pneumatic pressure to a
selected pumping means 80, 82, for example and to control actuation
of the cylinder means 28. Material to be sprayed would therefore be
pumped by pump means 80, 82 through the associated material supply
hose 24 to changer 10. This material would be delivered to spray
apparatus supply hose 56 to be sprayed from nozzle 88. The lateral
position of movable plate member 14 relative to stationary plate
member may be communicated from switch member 86 to central
processing unit 90 by conductor means 98.
Referring now to FIG. 5, a fragmentary view of a portion of the
stationary and rotary plate members 12, 14 according to the present
invention and showing an alternate valving and sealing mechanism is
illustrated. According to the structure of FIG. 5, each of the
passages 22 of the stationary plate member 12 is provided with a
displaceable check valve means 100 and a separate sealing means
102. In the illustrated embodiment, the check valve means is
comprised of a ball member 104 which is urged toward a seat 106 by
resilient means 108. Valve seat 106 is provided in combined valve
seat and seal member 110 which may be formed of a resilient
material. Movable plate member 14 is similarly provided with a
complementary seal forming member 112 which is arranged to coact
with the member 110 to provide a fluid tight seal between the
passage 122 of stationary member 12 and the passage means 54 of the
rotary member 14. As illustrated in the FIG. 5 embodiment,
cooperating sealing member 12 is provided with a central aperture
158 which is aligned with the similarly provided aperture within
the seal member 110.
Passage 54 is further provided with means defining a check valve
displacing element, finger 114, which is situated within passage
means 54 and arranged to project outwardly from the movable member
14 so as to engage, and displace, the ball member 104 of the check
valve means 100. In the illustrated embodiment, each of the
passages 122 of the stationary member 12 is provided with a
combined valve seat and seal member 110. The cooperating seal
member 112 is here illustrated as being an annular member arranged
about the periphery of movable plate member 14 and which is
radially spaced so as to engage the cooperating seat forming member
110. As illustrated, seal member 112 possesses but a single
aperture 158.
It will be appreciated that the present invention readily
accomplishes its stated objectives. By providing structure which is
situated between the confronting faces of the stationary and rotary
plate members, double sealing is provided to 1) provide a fluid
tight seal between the spray apparatus supply hose 56 and the
selected supply passage of the stationary plate member in
communication with hose 56 while 2) sealing the nonselected supply
passages of the stationary plate member from any contamination
which might be inadvertently introduced into the region between the
plate members 12, 14 from the operation of changer 10. Furthermore,
the present invention provides a mechanism by which any residual
powders remaining within the spray apparatus supply structure may
be exhausted so as to avoid any contamination forming residues when
switching from a spray operation involving a first sprayable
material to a spray operation involving a second sprayable material
which may be incompatible with the first sprayable material because
of color or other differences. By the rather direct expedient of
enlarging the diameter of the stationary and rotary plate members
and by suitably arranging the indexing means 64 to accommodate for
different sizes and different angular spacings between the
stationary plate member passages, an indefinitely large number of
different sprayable materials may be communicated to a single spray
apparatus while avoiding the risk of contamination between
different sprayable materials and assuring the availability of a
flushing action when switching between two dissimilar and
incompatible sprayable materials. Furthermore, multiple spray
apparatus may be provided by utilizing multiple porting and
multiple supply hoses.
While my invention has been described with reference to a
particular utilization and specific exemplary structure has been
described, the practitioner will recognized that certain
modifications may readily be made. For example, the changer
apparatus may be used with material supplies which are not
fluidized and need not be limited to use with powders. The
translatory and indexing structure may be constructed to provide a
nonrotary piston member sealingly coupled to a single through shaft
with the shaft being slidingly splined to either the movable plate
or the indexer, or the shaft may be fixedly attached to both with
the indexer being slidingly and nonrotarily coupled to the
stationary plate member.
* * * * *