U.S. patent number RE30,968 [Application Number 06/060,822] was granted by the patent office on 1982-06-15 for attachment for paint spray gun systems.
This patent grant is currently assigned to Champion Spark Plug Company. Invention is credited to Colonel E. Grant.
United States Patent |
RE30,968 |
Grant |
June 15, 1982 |
Attachment for paint spray gun systems
Abstract
A spill preventing diaphragm attachment for a paint spray gun
paint cup as shown. The diaphragm is engaged around the mouth of
the paint cup and forms, with the undersurface of the paint cup
lid, a chamber above the paint in the cup that is deeper at one
side than the other. At the deep side, oriented 180.degree. away
from the vent opening in the lid is a vent opening in the
diaphragm. Any paint that might flow through the diaphragm vent
opening as a result of tipping the spray gun drains back into the
cup as soon as the gun is righted. The diaphragm is readily
replaceable without tools.
Inventors: |
Grant; Colonel E. (Toledo,
OH) |
Assignee: |
Champion Spark Plug Company
(Toledo, OH)
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Family
ID: |
26740397 |
Appl.
No.: |
06/060,822 |
Filed: |
September 24, 1979 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
666192 |
Mar 12, 1976 |
03990609 |
Nov 9, 1976 |
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Current U.S.
Class: |
222/111 |
Current CPC
Class: |
B05B
14/00 (20180201); B05B 7/2408 (20130101) |
Current International
Class: |
B05B
7/24 (20060101); B05B 15/04 (20060101); B05B
001/28 () |
Field of
Search: |
;222/111,193,181,109,635
;239/121,122 ;220/324 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tollberg; Stanley H.
Attorney, Agent or Firm: Emch; Richard D.
Claims
What I claim is:
1. An attachment for a spray painting apparatus comprising a spray
gun and an open-mouth paint cup, a lid seated on said paint cup to
close the same with a peripheral seal against leakage, said lid
having a vent opening therein, a delivery tube extending from the
lower side of said paint cup to said spray gun, means to attach
said delivery tube to said lid for removal therewith.Iadd., said
attaching means including a locknut; .Iaddend.said attachment
consisting of a diaphragm having a peripheral flange for engagement
between the peripheral seal of said lid and said paint cup, a
downwardly extending wall inwardly of said flange and of
progressively increasing length forming with said diaphragm a
chamber that is deeper at one side than at the opposite side, said
deeper side being oriented away from the vent opening in said lid
and having a second vent opening in the lower surface thereof, and
means in the center portion of said diaphragm to engage said
delivery tube and delivery tube .[.retaining.]. .Iadd.attaching
.Iaddend.means in a substantially liquid-tight connection
.Iadd.said engaging means including a formed boss which mates with
said locknut for maintaining said diaphragm second vent opening in
a spaced relationship to said lid vent opening..Iaddend.
2. An attachment in accordance with claim 1 in which the vent
opening in the deeper portion of said diaphragm is oriented on the
opposite side from the vent opening in said lid.
3. An attachment in accordance with claim 1 in which said
peripheral diaphragm flange forms the seal between said lid and
said cup.
Description
BACKGROUND OF THE INVENTION
The invention relates to an attachment for the paint cup of a
well-known type of spray painting apparatus. The paint cup is
secured to a spray gun and flow of pressurized air through or about
the gun nozzle creates a partial vacuum at the fluid discharge
orifice of the spray gun. Atmospheric pressure entering a vent
opening in the lid of the paint cup acting upon the contents of the
paint cup causes the paint to flow through a delivery tube to the
fluid discharge orifice of the spray gun nozzle. The delivery tube
is mounted on the lid or cover for the cup and is removable
therewith, and the inner end of the delivery conduit extends to the
bottom of the cup, usually adjacent the front wall thereof. The
vent opening is normally formed in the lid or cover near an edge
thereof as, for example, at the side.
The existence of the vent opening has in the past given rise to the
danger of leakage through the opening onto the lid or cap, which in
turn often dripped on the operator or the target, creating an
undesirable condition which requires constant attention on the part
of the operator. As the level of liquid in the paint cup is reduced
the tendency to leak is, of course, also reduced so that many
operators will only partially fill the cup thus effectively
reducing the capacity of the system and requiring more frequent
filling than usual.
It has been proposed to overcome the above disadvantages and to
provide a system wherein leakage through the vent opening does not
occur. This has been achieved by using a conduit or pipe threaded
into the lid and effectively extending the vent opening so that the
outer end of the vent opening is accessible to the interior of the
paint cup through a trapped column of air even if the inner end of
the conduit is below the liquid level. If the inner end of the
conduit is above the liquid level, there will of course be no
leakage. The pipe or conduit is arranged so that a column of air
must be trapped before liquid can flow through the outer end of the
vent opening. In use, the operator must return the cup to its
upright position so that the conduit is above the liquid level. The
foregoing is shown and described in the patent to Dalton Jr. U.S.
Pat. No. 3,240,398.
BRIEF DESCRIPTION OF THE INVENTION
The present invention provides a simple diaphragm as an attachment
to a paint cup which is forced in place over the conventional
delivery tube and around the locknut that holds the delivery tube
in assembled relation to the cap or cover for the paint cup. It is
not necessary to drill any parts or replace any of the normal cap
elements. The simple diaphragm that is installed is engaged by the
lid of the paint cup at its periphery. With the diaphragm installed
the spray gun may be tilted downwardly or upwardly or from
side-to-side and normal spraying will still take place without
spilling paint from the cup onto the surfaces of the lid or cover.
The diaphragm attachment may be made to fit existing spray
guns.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings FIG. 1 is a front elevational view of a spray gun
and paint cup in assembled relation with parts shown in section
indicating the installation of the attachment of the present
invention.
FIG. 2 is a section on line 2--2 of FIG. 1.
FIG. 3 is a top plan view of a diaphragm attachment of the present
invention adapted to be placed over the locknut of a conventional
apparatus.
FIG. 4 is a side elevational view, with parts broken away, of the
diaphragm attachment of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
In the drawings, 10 designates a conventional paint cup typically
having a capacity of one quart, and a full line 1-11/16 inches
below the lip of the cup. The cup is held into assembled relation
to a spray gun 12 by a quick disconnect yoke 14 and a hold-down
lever 16 having a conventional cam 18 which urges the yoke 14
upwardly. The yoke 14 has depending arms 20 which engage trunnions
22 extending from the cup. The cam 18 works between the web of the
yoke 14 and the upper surface of a lid or cover 24 which closes off
the top of the paint cup after the latter has been filled. Usually,
a gasket 25 is recessed into the undersurface of the lid or cover
where engagement with the lip of the paint cup 10 takes place to
prevent leakage at this point.
A delivery tube 26 extends from a point near the bottom of the cup,
usually adjacent the front wall thereof and is inserted into the
cover 24. A fitting 28 attaches to the spray gun indicated
generally at S in a known manner. The assembly is made with the
delivery tube 26 underlying the spray gun so that the gun sprays in
the direction of the displacement of the tube from the center of
the bottom of the cup 10.
The delivery tube assembly, having been inserted into the cap or
cover is held in place by a locknut 32 which bears against the
underside of the lid. The lid 24 has a vent opening 40 in one side
thereof at a point underlying the web of the attachment yoke
14.
The attachment of the present invention comprises a diaphragm 42
which includes an outwardly extending peripheral flange or lip 44
secured, in use, between the gasket 25 and the peripheral upper
surface of the paint cup. Inwardly from the outwardly extending
peripheral flange 44 the diaphragm 42 has a vertical portion 46
connected to the main central portion 48, and the main central
portion 48 slants from one side to the other. Under the vent
opening 40 the diaphragm is quite closely spaced with relation to
the undersurface of the cap while at the opposite side the slanting
configuration of the diaphragm 42 brings the surface of the
diaphragm well away from the undersurface of the cover and forms a
chamber 50 which is thus deeper at one side than at the other. At
the deep side of the chamber 50, a small drain chamber 52 is
provided in the form of a hemispherical dimple 54. A vent opening
56 extends through the bottom of the dimple 54 and the diaphragm is
assembled to bring this vent opening 56 180.degree. away from the
vent opening 40. The normal vent path for air entering the paint
cup 10 during spraying is through the vent opening 40, through the
interior of the chamber 50 and the venting opening 56. The
inclination of the diaphragm allows any paint that is trapped in
the cavity between it and the lid to quickly drain back into the
paint cup 10 when the cup is returned to the normal vertical
position.
It will be seen that there is no direct access from the interior of
the paint cup 10 to the vent opening 40. The opening 40 is thus
spill-proof. In use it has been found that with a full paint cup
the second vent opening 56 may be immersed in paint if the operator
so tilts the spray gun from one side to another but that spraying
will continue in spite of this immersion. Air entering the spray
gun simply bubbles through the paint from the vent opening 56. At
its center the diaphragm 42 is molded or formed with an integral
boss 60 which is of the same size and shape as the locknut 32 which
holds the delivery tube in place on the cover 24. The diaphragm may
thus be mounted in place below the cover merely by sliding it up
the delivery tube 26 until a diaphragm boss 64 contacts the
underside of lid 24. The inner diameter of the opening 62 below the
boss 60 which surrounds the delivery tube is purposely made small
so that the material of the diaphragm boss is slightly distorted as
the diaphragm is forced over the delivery tube and its locknut.
There is thus a liquid-tight seal at this point.
In operation, the paint cup is filled in the usual maner. The
diaphragm 42 is run upwardly over the delivery tube 26 until the
integral boss 64 contacts the bottom of the lid 24. At this time
the peripheral flange 44 will have engaged under the cover gasket
25. The diaphragm 42 is oriented in such a manner that the dimple
or well 52 is at the side of the lid or cover opposite the vent
hole 40. The cover or lid may then be assembled onto the paint cup
in the usual manner.
If the operator tilts the spray gun in any direction there will be
no leakage through the vent opening 40. A small quantity of paint
may enter into the chamber 50 if the diaphragm vent opening 56 is
immersed in the paint by reason of the operator tilting the entire
system including the spray gun in a clockwise direction in FIG. 1.
Spraying will continue, however, but no paint will spill out of the
opening 40 because this opening is always higher than the paint
level in any except an inverted position of the paint cup. Assuming
that some paint enters the chamber 50 through the vent opening 56
it will be immediately sucked back into the paint cup when the cup
and gun are restored to a vertical position and spraying resumed.
In order to clean the diaphragm if such should ever become
necessary it is only required that the operator pull the diaphragm
away from the locknut and clean its upper surface. In many cases
the diaphragm can be cleaned in place by simply putting solvent in
the cup, replacing the lid and sloshing it around. The diaphragm
can be replaced since the element is quite inexpensive.
* * * * *