Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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LEAK DETECTING APPARATUS
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a completion application of and claims the
benefit of U. S. Provisional Application No. 60/906,067, filed March 9, 2007,
the
entire disclosure of which is incorporated herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention pertains to apparatus for use in testing the
fluid tightness of closed vessels or fluid systems, such as found in the
pressurized
cooling system of an internal combustion engine and the fluid transmission of
an
automobile, and more particularly, to apparatus for detecting and/or
quantifying
fluid leakage from a fluid system that is under pressure when in use, such as
through imperfections in the housing or sealing structure of the fluid system
whereby to warn the provider of such fluid system that a leakage condition
exists.
2. Description of the Prior Art
[0003] The automobile is comprised of many components that take many
forms and some are very complex, such as the engine and the coolant system for
circulating coolant for cooling the engine cylinders. The engine is assembled
from separate parts, some possibly die cast, to form a housing having various
ports, internal passageways and/or inside chambers, and seals. The walls and
junctions of the engine housing may have minor imperfections, and the
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components, when assembled, may have a gap or minor separation between
mated parts, and thus have a potential for developing a leak.
[0004] In these systems, fluids are introduced into interior -fluid chambers
at high positive pressure. Since the fluid system operates at atmospheric
pressure, if there is a hole or imperfection in the construction of the fluid
system,
the pressure differential will cause the fluid inside the system to be forced
outside (i.e., develop a vapor leak).
[0005] A vapor leak in the engine cylinder can cause a lean condition in the
engine air-fuel mixture, which in turn can lead to serious engine damage, such
as piston seizure, detonation, and the like. Further, a drop in pressure or a
decrease in the amount of pressurized coolant fluid delivered by the vehicle
water pump due to leakage may result in a failure of the pump to provide
necessary cooling and the engine to overheat.
[0006] Importantly, the engine manufacturer wants to minimize the
likelihood of leakage because a drop in pressure could affect the performance
of
the engine and leakage of fluids under pressure could possibly violate various
environmental laws. If for some reason the engine has to be recalled to fix a
problem, or some other operational reason, this is very expensive and creates
customer dissatisfaction with the product. Accordingly, engine manufacturers
typically check fluid systems prior to shipping or installation for use.
[0007] In general, any fluid system that is to be checked for leakage has an
interior fluid chamber, or air space, for receiving a predetermined supply of
pressurized fluid. In some cases the volume of the fluid chamber is known, and
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in others, the volume is not known, or at least not known with any degree of
precision. That is, the amount (or mass) of pressurized air required to
conduct a
fluid leakage test might not be known from unit to unit. For example, in a
transmission, the supplier may pre-fill the fluid chamber thereof with a
quantity
of transmission fluid. As such, neither the internal volume and/or air/fluid
percentage of the chamber is known precisely from unit to unit.
[0008] Like other forms of nondestructive testing, leak testing has a great
impact on the safety or performance of a product. Reliable leak testing saves
costs by reducing the number of reworked products, warranty repairs and
liability claims. The time and money invested in leak testing often produces
immediate profit.
[0009] Various apparatus to check for leakage from hydraulic systems and
other systems have been proposed. By way of example, attention is drawn to U.
S. Pat. Nos. 3,320,801 (Rhindress, Jr.); 3,874,225 (Fegel); 4,047,423 (Eason);
4,617,824 (Cybulski, et al.); 5,333,492 (Aarts); 5,372,031 (Harmand);
5,760,294
(Lebmann); 6,351,985 (Bedwell); 6,619,109 (Dailey et al.); 6,655,193 (Liu),
and
6,907,771 (Finlay et al.).
[0010] These patent documents are believed to disclose improvements in
the art that were suitable for the particular problem to be then solved and
are
listed in recognition of the duty of disclosure of related subject matter
which may
be relevant as prior art under 37 CFR 1.56.
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[0011] It is to be appreciated that there is an ongoing need for
improvements in the apparatus and methodology for the testing of automobile
engines for the presence of a leak prior to being shipped.
[0012] Desirably, an apparatus for testing a fluid system for leakage would
not require that the volume of the fluid chamber be known, only that the leak
test apparatus be capable of attachment to an inlet of the fluid system and,
at
least in part, cooperate with a source of pressurized fluid to introduce
pressurized fluid into the interior chamber of the fluid system and provide an
indication that there is, or not, any fluid leakage from the fluid system. In
this
aspect, hidden internal volumes in a complex fluid system, which could effect
leak measurements, should not affect the ability of the leak testing apparatus
to
test for leakage.
[0013] Further, the apparatus for testing for fluid leakage would desirably
be inexpensive and not require the leak measuring apparatus to gain physical
access into the interior fluid chamber of what is oftentimes a previously
assembled/sealed unit.
SUMMARY OF THE INVENTION
[0014] The present invention achieves the above desired objects and
discloses a method and an apparatus for testing a fluid system adapted to
operate under pressure for fluid tightness by detecting and quantifying the
presence of a leak from such system whereby to warn the provider of such fluid
system that a fluid leak is present in the fluid system being supplied.
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[0015] According to this invention there is provided an apparatus for leak
testing a sealed fluid system having a fluid inlet tube for communicating
fluid
into an interior fluid chamber of the fluid system. Depending on the
application,
the apparatus may be hand held, and positioned by the user, or incorporated
into
a robotically controlled assembly line. The apparatus comprises:
an adapter body including a rearward end wall and a sidewall including a
cylindrical inner wall extending forwardly of said end wall to form a cup-
shaped
receptacle sized to receive and fit about the outer periphery of said inlet
tube,
and first and second passages, said passages being separate and apart from one
another, connectible to a source of fluid at high pressure, and extending from
the
rearward end wall and opening in said receptacle, and
a hollow cylindrical bladder seal disposed in said receptacle and in
centered relation with said second passage, said bladder seal having inner and
outer surfaces with said outer surface being juxtaposed with and spaced
inwardly from the inner wall and said inner surface being adapted to encircle
the
outer periphery of said inlet tube, when said tube is received in said
receptacle,
the first passage being adapted to supply pressurized air into the space
between
the outer surface of the bladder seal and the inner wall of the receptacle and
compress the bladder seal radially inwardly and into air tight sealed relation
with the outer periphery of the inlet tube, and the second passage being
adapted
to supply pressurized air into said inlet tube and pressurize said fluid
chamber.
[0016] According to this embodiment, the apparatus further comprises:
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a first and second valve for preventing and permitting pressurized air to
pass from the source of pressurized air, the first valve being associated with
the
first passage and controlling the flow of air into the annular space between
the
bladder seal and the inner wall of the receptacle, and the second valve being
associated with the second passage and controlling the flow of air into the
inlet
tube, and
means for measuring and indicating the decrease, if any over time, of the
pressure in the fluid chamber.
[0017] The apparatus further comprises a donut shaped sealing assembly
disposed in said receptacle, and means for removably retaining said sealing
assembly in said receptacle. The sealing assembly comprises an outer support
assembly, and the bladder seal. The support assembly includes an outer support
ring of relatively inflexible material, and an inner actuating ring of
resiliently
deformable material, and means for connecting the rings to one another. The
bladder seal is of a compressible elastomeric material
[0018] The rings and bladder seal have outer and inner walls. The outer
and inner walls of the support ring each include an annular recess and at
least
one air passage that.passes between the annular recesses. Importantly, the
annular recesses cooperate to uniformly distribute pressurized air 360 about
the
support ring and 360 about the inner actuating ring to uniformly compress an
annular wall portion of the bladder seal radially inwardly and about and into
air
tight sealing relation with the outer periphery of the inlet tube.
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[0019] As to the support ring, the outer wall and annular recess therein
are juxtaposed with the inner wall of the receptacle and the annular recess
thereof disposed in fluid communication with the first passage and the annular
space between the bladder seal and receptacle wall, and the inner wall and
annular recess therein are juxtaposed about and with the outer wall of the
actuating ring.
[0020] The inner wall of the actuating ring, at least in part, encircles and
is abutted against the outer wall of the bladder seal. Fluid under pressure
from
the first passage passes into the annular space between. the bladder seal and
the
inner surface of the sidewall that forms the receptacle, into and about the
outer
annular recess, through the air passage, and into the inner annular recess,
and
around and against the actuating ring. This pressure forces the wall of the
actuating ring, at least in part, radially inward against an annular wall
portion
of the bladder seal and compresses this wall portion of the bladder seal
radially
inwardly against and about the outer periphery of the inlet tube wherein to
form
a fluid tight seal about the outer periphery of the inlet tube.
[0021] In such sealed connection, pressurized air from the second passage
is introduced into the inlet tube, and thereafter into the chamber of the
fluid
system to be checked for air or vapor leakage.
[0022] According to a hand held arrangement, the apparatus further
comprises first means for centering and aligning the adapter body with the
inlet
tube and placing the second passage in direct fluid communication with the
inlet
tube. According to this arrangement, the first means comprises an elongated
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hollow centering tube coaxially disposed in said receptacle, at least in part,
the
centering tube having a proximal end portion connected to said end wall and
forming a continuation of said second passage, and a distal end portion
adapted
to be inserted into the inlet tube and communicate pressurized, fluid from the
source to said chamber. Preferably, the sealing assembly, centering tube, and
second passage are coaxially disposed relative to one another and the
receptacle.
[0023] According to an embodiment of this invention, a leak check module
for detecting fluid leakage from a fluid system comprised of parts separately
assembled or cast, the fluid assembly defining an interior fluid chamber and
including a fluid inlet tube having a center passage for communicating fluid
into
the fluid chamber, the leak check module comprising,
a housing, said housing having a base member and a sidewall extending.
from the base to form a cup shaped receptacle for receiving and encircling
said
inlet tube, and first and second fluid passages, said passages separated from
one
another and connectible to a fluid source for supplying pressurized air into
the
receptacle, said first fluid passage for communicating pressurized air into
the
center of said receptacle and into said inlet tube when said inlet tube is
received
in said receptacle,
a tubular bladder seal of a compressible elastomeric material disposed in
said receptacle, said bladder seal having inner and outer walls, respectively,
juxtaposed with the inlet tube when disposed in the receptacle and with the
sidewall of said housing, opposite ends, and an annular wall portion disposed
between the ends,
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first means for engaging and forcing said annular wall portion radially
inwardly and from a first position spaced form said inlet tube and into a
second
position disposed in clamped fluid tight relation with the outer periphery of
said
inlet tube, said first means being disposed in fluid relation to said second
fluid
passage, and
second means for removably captivating said bladder seal and said first
means in said receptacle with said bladder seal having one and the other end
distal and proximate to the opening to said receptacle, said second means
being
proximate to and engaging the other end of said bladder seal.
[0024] According to this embodiment of the invention, the first means for
engaging and forcing comprises
a hollow cylindrical actuating ring of resilient polymeric material, the
actuating ring including a cylindrical wall having a medial annular wall
portion,
a hollow cylindrical packing ring of rigid material, the packing ring
having, respectively, an outer and an inner annular recess, and a plurality of
fluid apertures extending between the annular recesses, and
means for connecting the rings to one another and positioning the fluid
apertures and respective recesses to communicate fluid from the first passage
and distribute fluid 360 both about the annular recesses and against the
annular wall portion.
[0025) According to this invention, there is provided instant leak tight
connection to formed tube ends such as beads and barbs or threaded portions
found on tube assemblies reservoirs and cast parts, and forms a vapor seal by
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compressing about or gripping the outside of such tube end, such as by
gripping
barbed or flared or beaded or threaded portions, where the tube is used for
connection in use, without damaging the tube portions.
[0026] According to another embodiment, a method of leak testing an
engine component of the type having a cavity therein through which cooling
water can circulate, there being an inlet port which projects from a face of
the
engine component and communicates fluid into the cavity, which method
comprises, associating a testing apparatus, according to this invention, with
the
inlet port, the associating including abutting an end face of the inlet port
with a
mating face of the testing apparatus and positioning the bladder seal -of the
testing apparatus in encircling relation about the outer periphery of the
inlet
port, and placing the outer wall of the bladder seal in fluid communication
with a
first fluid passage and the inlet port in fluid communication with a second
fluid
passage, and thereupon sequentially supplying fluid under pressure to the
first
and second fluid passages to press the bladder seal into sealing relation
about
the outer periphery of the inlet port and pass fluid into the second passage
and
into the cavity through the inlet port inlet, the pressurized fluid
establishing a
pressure at the inlet to the testing apparatus and an outlet of the cavity,
and
measuring and comparing the pressures at the inlet and the outlet, leakage
from
the engine cavity being indicated when the pressure value at the outlet is
less
than the pressure value at the inlet.
[0027] According to this invention, in an embodiment thereof, there is
provided a leak testing device for attachment to a fluid system to be leak
tested,
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the system having a sealed interior chamber and a fluid inlet tube having an
opening leading to the chamber and connectible to a source to selectively
pressurize and depressurize the interior chamber of the fluid system, said
device
comprising
a sealing head including a sidewall and end wall, the walls forming a cup-
shaped receptacle for receiving and positioning the inlet tube in the
receptacle
and an annular recess at the junction between the sidewall and the end wall,
a sealing assembly concentrically disposed in the receptacle and including
a bladder seal of compressible elastomeric material and a support assembly,
the
bladder seal being adapted to encircle the inlet tube when inserted into the
receptacle and compress radially inward and into sealed relation with -the
outer
periphery of the tube upon application of an inward force against the outer
periphery of the bladder seal, and the support assembly being disposed between
the sidewall and the bladder seal and having a lower cylindrical end portion
juxtaposed atop the annular recess,
a first passage for communicating pressurized air from the source into the
annular recess,
means for communicating pressurized air from said annular recess against
the outer periphery of the bladder seal wherein to compress the bladder seal
radially inwardly and into air tight sealing relation about the outer
periphery of
the inlet tube without blocking the opening thereof,
a second passage for communicating pressurized air from the source into
the receptacle and into the opening of the inlet tube,
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means for selectively permitting and preventing air to pass from said
source to said first and second passages, and
means for captivating said sealing assembly and bladder seal in said
receptacle.
[0028] The leak testing device of this embodiment preferably further
comprises means for measuring the pressure in the first and second passages,
and means for providing an indication of the difference between the pressures
over a predetermined time, the difference being reflective of air leaking from
the
object being tested.
[0029] Further, in this leak testing device, the means for captivating
comprises a donut shaped closure ring, the closure ring including first face
that
is juxtaposed against the sealing assembly, and an exterior face, the exterior
face
being frustoconical and converging inwardly wherein to accommodate radial
enlargements on the inlet tube.
[0030] The leak testing device, further comprising a handle having
opposite rearward and forward end portions, the sealing head being disposed at
a
predetermined angle relative to the forward end portion and removably mounted
thereto and in fluid relation with the source.
[0031] In another embodiment reflective of this invention, an apparatus for
leak testing a sealed fluid system having a fluid inlet tube for communicating
fluid into an interior fluid chamber of the fluid system comprises:
an adapter body including a rearward end wall and a sidewall including a
cylindrical inner wall extending forwardly of said end wall to form a cup-
shaped
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receptacle sized to receive and fit about the outer periphery of said inlet
tube,
and first and second passages, said passages being separate and apart from one
another, connectible to a source of fluid at high pressure, and extending from
the
rearward end wall and opening in said receptacle, and
a hollow cylindrical bladder seal having inner and outer surfaces, said
bladder, seal disposed in said receptacle with the outer surface thereof being
juxtaposed with and spaced inwardly from the inner wall and the inner surface
thereof being adapted to encircle the outer periphery of said inlet tube, when
said tube in received in said receptacle, and center the second passage with
the
opening at the end of the inlet tube, the first passage being adapted to
supply
pressurized air into the space between the outer surface of the bladder and
the
inner wall of the receptacle and against the bladder seal and compress the
bladder seal and the inner surface thereof radially inwardly and into air
tight
sealed relation with the outer periphery of the inlet tube, and the second
passage
being adapted to supply pressurized air into said inlet tube and pressurize
said
fluid chamber. .
[0032] In the aforesaid adapter, there is provided:.
a first and second valve for selectively preventing and permitting
pressurized air to pass from the source of pressurized air, the first valve,
being
associated with the first passage and controlling the flow of air into the
annular
space between the bladder seal and the inner wall of the receptacle, and the
second valve being associated with the second passage and controlling the flow
of air into the inlet tube and into the fluid chamber, and .
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means for measuring and indicating the decrease, if any over time, of the
pressure. in the fluid chamber.
[0033] The adapter is characterized by a donut shaped sealing assembly
disposed in the receptacle, and means for removably retaining the sealing
assembly in said receptacle. The sealing assembly is disposed in said
receptacle
and in coaxially centered relation with the centering tube and the second
passage opening on the center of the end wall.
[0034] Preferably, the adapter further comprises means for centering and
aligning the second passage with the inlet tube and placing the second passage
in direct fluid communication with the inlet tube. In an aspect thereof,. the
means for centering comprises an elongated hollow centering tube that is
coaxially disposed in said receptacle, at least in part, the centering tube
having a
proximal end portion connected to said end wall and forming a continuation of
said second passage, and a distal end portion adapted to be inserted into the
inlet tube and communicate pressurized fluid from the source to said chamber.
Preferably, the distal end portion of the centering tube extends from the
receptacle and aids the user in placing the adapter relative to and within the
inlet tube and to establish fluid relation with the fluid chamber of the fluid
system.
[0035] In a particular aspect of this embodiment, the sealing assembly
comprises:
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an outer support assembly, said support assembly including an outer
support ring of relatively inflexible material, and an inner actuating ring of
resiliently deformable material, and
said bladder seal, said bladder seal of a compressible elastomeric material,
and
means for connecting the rings to one another.
[0036] According to this sealing assembly,
the rings and bladder have outer and inner walls,
the outer and inner walls of the support ring each include an annular
recess and at least one air passage that passes between the annular recesses,
with the annular recesses in the outer wall and inner wall of the support
ring,
respectively, being juxtaposed with the, inner wall of the receptacle and in
fluid
communication with the first passage thereof and juxtaposed with the outer
wall
of the actuating ring, and
the inner wall of the actuating ring is abutted against the outer wall of the
bladder seal,
wherein fluid pressure from the first passage passes into the space
between the bladder and sidewall, into the outer annular recess, and through
the
air passage and into the inner annular recess to force the wall of the
actuating
ring radially inward against the bladder seal and compress the inner wall of
the
bladder seal radially inwardly and into sealing relation with the inlet tube.
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[0037] The present invention will be more clearly understood with
reference to the accompanying Drawings and to the following Detailed
Description, in which like reference numerals refer to like parts and where:
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a perspective view of hand-held leak check apparatus
according to the present invention, wherein a leak check module thereof is
connected to a source of pressurized air and positioned for pressure sealed
connection to the fluid intake port of a conventional automobile water pump
and
introduce pressurized air to a closed interior chamber of the pump housing,
and
wherein a monitoring circuit measures leakage, if any, from the water pump
when pressurized;
[0039] FIG. 1A illustrates the shape of the fluid intake port for introducing
pressurized fluid into the interior chamber of the water pump;
[0040] FIG. 2 is an assembly view of the hand-held apparatus of FIG. 1
with certain elements of the leak check module shown in section;
[0041] FIG. 3 is a perspective view showing detail of an intermediate seal
actuating ring and an apertured outer packing ring, shown in FIG. 2,
positioned
for assembly to one another to form a support assembly positionable about an
inner bladder seal;
[0042] FIG. 4 is a perspective assembly view of the leak check module : of
FIG. 2 and components thereof positioned for assembly to a closure cup of the
leak check module, and wherein certain of the components and closure cup
thereof have portions cut-away and are shown in section;
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[0043] FIGS. 5A, 5B, and 5C are, respectively, a side view, partially in
section, an end view, and a front view of the assembled leak check module;
[0044] FIG. 6 is a side elevation view in section of the closure cup, a
sealing assembly captivated in a receptacle of the closure cup, and the fluid
intake port positioned in the closure cup and encircled by the inner bladder
seal
prior to the seal being compressed into a sealed fitment about the -outer
periphery of the intake port; and
[0045] FIGS. 7 and 8 are partial side elevation views, in section, of
additional preferred embodiments according to this invention, of leak check
modules for leak testing connection about the inlet and/or outlet to a fluid
compressor of an automobile engine, the modules being adapted to be controlled
and positioned by a robotic system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] Turning now to the drawings, there is disclosed a leak' =testing
apparatus and a method for use in testing the fluid tightness of a
pressurizable
fluid delivery system and detecting the occurrence of leaks through passages
and
imperfections of the fluid delivery system to warn the provider of such
delivery
system that a fluid leakage condition exists. Importantly, the leak testing
apparatus of this invention does not require that the user know the size or
volume of the interior chamber or air space of the fluid delivery system being
tested.
[0047] Embodiments of the leak testing apparatus according to the
invention herein are described for use in connection with testing the fluid
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tightness of a coolant system of an automobile, such as the water pump or the
turbine or the compressor unit of an internal combustion engine. However, the
invention is not limited to the applications illustrated and may be used on
other
sealed fluid systems having an interior air space or chamber for receiving a
pressurized fluid, such as a fluid transmission system. '
[0048] Further, embodiments of the leak testing apparatus according to
this invention are configured to be hand held and manually positioned relative
to
parts to be leak tested as well as robotically positioned. Desirably, the
components of the leak testing apparatus, whether hand held or robotically
positioned, are adapted to enable interchangeability because typically the
fluid
inlets of the fluid systems to be tested have a like shaped end portion and
thus
the leak testing components need only be changed in dimension (e.g.,
diameter).
For example, in a hand held situation, the user may rapidly change components
of a sealing assembly and thereby reconfigure the leak testing apparatus for
use
on different coolant systems to be tested. In the situation wherein the tester
is
adapted for use in an assembly line and positioned by a robot, a bladder seal
of
the testing apparatus is easily changed to form a fluid seal about the inlet
and/or
outlet sleeve of a turbine or compressor.
[00491 Referring to FIG. 1, a hand held leak check apparatus according to
this invention for detecting fluid leakage from a fluid system, such as from a
water pump 12 of an automobile engine, is indicated by the reference numeral
10. The leak check apparatus 10 is adapted to connect to and place a
regulatable
source of pressurized air, indicated at 14, in fluid communication with and
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selectively prsssurize and/or depressurize an interior chamber 16 of the water
pump 12.
[0050] The regulatable air source 14 includes a first supply line. 18 for
supplying pressurized air to a cylindrical sealing assembly 48, which is
adapted
to encircle an inlet tube 26 of the water pump to be tested, and a second
supply
line 20 for supplying pressurized air through the inlet tube 26 and directly
into
the interior chamber 16 of the water pump 12. The supply lines 18 and 20 are
separate and apart and not in fluid communication with one another: Each
supply line 18 and 20 is regulatable, such as by a suitable check valve 19 and
21,.
to prevent, supply, or selectively change the amount of pressurized fluid
supplied
by the source 20 to the part to be tested. A manually regulated check valve 38
permits the user to selectively supply pressurized air to be delivered through
the
supply line 20.
[0051] A monitoring circuit 22 is associated with the pressure source 14 to
monitor and measure the air pressure in each supply line 18 and 20, such as
illustrated by the pressure gauges 22a and 22b. Further, a read-out gauge 22c
operates to provide an output reading of a selected parameter, such as the
difference in the readings of the gauges 22a and 22b.
[00521 If the parameter being monitored drops in value, or drops in value
over a predetermined time and by a predetermined amount, this is an indication
of leakage and the water pump 12 is rejected. The leakage may be measured by
loss of pressure and/or drop in pressure resulting from the escape of air from
the
interior chamber 16 of the water pump 12.
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[0053] For example, depending on the application, the regulatable. air
source 14 may be set to supply air to the supply line 18, and thus to the
sealing
assembly 48, at between 80 - 100 psig, and to the supply line 20, and thus to
the
interior chamber 16 of the pump housing, at about 60 psig. The leakage readout
gauge 22c may read a parameter, such as the actual pressure in the chamber 16,
or the drop in pressure in the chamber, or the rate of fluid flow from the
chamber. Importantly, the pressure supplied to the line 18 is preferably much
higher than that compared to the pressure supplied through the supply line 20
to
the coolant pump 12 to prevent blow-off, or minor axial backing off, of a leak
check module 30 of the leak check apparatus 10 from sealed relation with the
inlet tube 26 to the water pump.
[0054] In some applications, the leakage may be reflected in fluid mass
flow from the chamber of the pump. That is, the monitoring circuit 22 may be
adapted to measure rate or amount of fluid escape from the interior chamber
16,
as measured by a reference pressure of the pump chamber 16 and a known
measurement of the quantity of air supplied into the chamber 16 to achieve the
reference pressure. For example, a particular water pump may be rejected if a
leakage is greater than 5 cc/min.
[0055] The water pump 12 includes a pump housing 24, which defines a
closable interior chamber 16 for receiving engine coolant, the fluid inlet
tube 26
for passing coolant liquid into the interior chamber, and a#luid outlet (not
shown) for passing coolant from the interior chamber 16 and into the engine
(not
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shown). During a leak test herein, the fluid outlet of the engine is plugged
or
otherwise fluidly sealed.
[0056] As shown best in FIG. 1A, the fluid inlet tube or intake port 26 is
generally cylindrical, hollow, thin-walled, axially elongated and centered on
a
central axis "T", and projects upwardly and away from the pump housing 24.
The inlet tube 26 has a forward end face and fluid inlet opening 26a spaced
from
the pump housing 24 and defines a fluid passage 26b that extends inwardly from
the inlet opening 26a and communicates fluid into the interior chamber 16.
[0057] The fluid inlet tube 26 of the water pump 12 to be tested is
generally cylindrical but may differ as regards the wall thickness as well as
the
outside and/or inside diameters thereof. Further, the inlet tube 26 may be
configured to enable the water pump, or like fluid system, when in operable
use
with the engine, to fluidly connect to a water hose (not shown).
[0058] In an embodiment illustrated herein, the forward end portion of the
fluid inlet tube 26 is configured to include an annular rib 27 proximate to
the
inlet 26a, an annular limit shoulder 29 distal to the inlet, and a cylindrical
outer
surface 26c that extends between the rib 27 and shoulder,29. The annular rib
27
is formed by a frusto-conical surface that 27a that expands radially outwardly
and rearwardly of the inlet end 26a and terminates in a generally vertical end
wall 27b, the shaped annular rib being helpful in completing a gripping sealed
connection with the interior wall of a water hose when connected thereto.
[0059] Importantly, as will be described hereinbelow, a leak check module
30 according to this invention is provided with the sealing assembly 48, which
in
21
CA 02624429 2008-03-07
turn includes a cylindrical bladder seal 56 that is adapted to be subjected to
pressurized air from the supply line 20, circumferentially compress, and grip
and
form a fluid sealed connection around the forward end portion of the inlet
tube
26. The gripping of the tube end portion desirably provides an instant leak
tight
connection wherein the tube end portion 'is not damaged. ' The bladder seal 56
has opposite axial end faces 56f and 56r and is adapted to form a leak tight
gripping connection to tube ends formed with a different specific shapes, such
as
with the annular rib 27, beads and barbs, or threaded portions, and such -as
found on tube assembly reservoirs and cast parts.
[00601 Referring to FIG. 6, the bladder seal 56 encircles the exterior
cylindrical outer surface or wall 26c of the inlet tube 26. When the bladder
seal
56 is compressed radially inward, the inner face 56b thereof compresses about
the outer surface 26c. Preferably, the rearward axial end face 56r of the
bladder
seal 56, at least in part, is proximate to and juxtaposed with the end wall
27b of
the annular rib 27 to resist relative axial withdrawal movement between the
bladder seal 56 and the inlet tube 26. Seating of the end face 56f behind the.
shaped rib 27 inhibits axial blow-off of the inlet tube 26 from the leak check
module 30 during pressurized leak testing, thus minimizing potential for
injury
to the worker. [0061] As shown in FIG. 6, the rearward end wall 27b is
substantially
radially directed (i.e., disposed in a plane generally perpendicular to the
central
geometrical axis "T" of the inlet tube) and juxtaposed with the corresponding
axial end face 56r of the bladder seal 56.
22
CA 02624429 2008-03-07
[00621 Further, the cross-section of the annular rib 27 may differ,
depending on the water pump being tested. The exterior surface of the shaped
rib 27, in cross-section, may have differently angled forward and reward
exterior
surfaces relative to the tube axis, with one exterior wall surface of the rib
being
more or less acutely angled, and the surfaces forming a medial knee. The
bladder seal in such case might possibly be adapted to engage both of the
angled
surfaces as well as the knee portion thereof.
[0063] The annular rib 27 may not be provided in all situations, depending
on the particular application. The shape and decision to provide the annular
rib
is determined in part by the supplier of the water pump.
[0064] The leak check apparatus 10 includes a handle 28, formed by the
assembly of a pair of complernentary mating side walls 28A and 28B, and the
leak check module 30. The handle 28 forms an inlet and outlet end 28a and 28b
and the sidewalls 28A and 28B thereof assemble to captivate in separated
relation a pair of fluid conduits 32 and 34 for passing high pressure air from
the
supply source 14 through the handle. The inlet end 28a is adapted to fluidly
connect the fluid conduits 32 and 34 to a respective fluid supply line 18 and
20
and the outlet end 28b is adapted to fluidly connect the fluid conduits 32 and
34
to a respective fluid passage 40 and 42 in the leak module 30. A manually
operated flow control valve 36 is associated with the handle for selectively
permitting or preventing air to flow in the fluid conduit 32 and between the
opposite ends 28a and 28b of the handle 28.
23
CA 02624429 2008-03-07
[0065] The leak check module 30 includes a closure cup 44 having an
interior chamber or receptacle 46, the sealing assembly 48, nested in the
receptacle, and an end plate 50 for captivating the sealing assembly . in the
receptacle. The receptacle 46 of the closure cup 44 is adapted to receive and
the
sealing assembly 48 is adapted to "close about" the inlet tube 26. Then, upon
application of pressure from the source 14, the sealing assembly 48 forms a
fluid
tight sealed connection with the inlet tube 26 and the chamber 16 is
pressurized.
[0066] In an important aspect according to this invention, the outlet end
28b of the handle 28 may be configured such that the leak check module 30 may
be at a desired angle relative to the handle to enable the user to more
effectively
position the closure cup 44 relative to the inlet tube 26. Referring to FIG.
1, the
handle 28 is generally disposed on a central axis "C", and the leak check
module
30 is disposed on a central geometrical axis "A", which axis is approximately
at
an angle "B" of about 45 to the axis "C" of the handle 28. Depending on the
application, the outlet end 28b of the handle 28 and the fluid conduits 32 and
34
may be configured such the central axis "A" of the module 30 may be at any
desired angle "B" relative to the axis "C" and the end 28b of the handle 28.
For
example, if the angle "B" is 00, the closure cup 44 is at a right angle to the
central
axis "C" of the handle 28. If the angle is 90 , the central axis "C" of the
handle 28
and the geometrical axis "A" of the closure cup 44 are coaxially aligned with
one
another.
[0067] The closure cup 44 includes a cylindrical base member 52 having
opposite end walls 52a and 52b and a cylindrical sidewall 54 conjoined to the
24
CA 02624429 2008-03-07
base member and coaxially centered about the geometrical axis "A", the
sidewall
having a cylindrical interior sidewall surface 54a and a forward end 54b and
cooperating with the base member 52 to form the cup-shaped receptacle 46. The
end wall 52a of the base member 52 forms the rearward exterior end face of the
closure cup, which is connected to the outlet end 28b of the handle 28 and the
fluid outlets. of the fluid conduits 32 and 34. The end wall 52b forms, at
least in
part, the bottom of the receptacle 46.
[0068] As will be described herein below, an annular recess or air space or
cavity 68 is formed at the bottoni of the receptacle, and at the junction
between
the sidewall and the end face 52b of the base member 52.
[0069] A pair of fluid passages 40 and 42 extend between the opposite end
walls 52a and 52b of the base member 52 and each has, respectively, an inlet
formed on the end wall 52b and an outlet 40a and 42a that opens in the
receptacle 46. Mating threaded portions are provided at the inlet end portions
of
the fluid passages 40 and 42 and respective of the fluid conduits 32 and 34 to
enable the fluid conduits to fluidly removably connect to a respective. fluid
passage.
[0070] The fluid passage 40 extends through the base member 52 at an
acute angle to the axis "A" and the outlet 40a thereof terminates in the
annular
recess 68 formed at the junction between the sidewall and the endwall 52b of
the
base member 52. The outlet port 40a is positioned to supply pressurized air
into
and around the annular recess 68 and thereafter into a cylindrical annular
space
CA 02624429 2008-03-07
or separation formed between and about the interior sidewall of the receptacle
and the exterior surface of the seal assembly 48.
[0071] The fluid passage 42 and outlet 42a thereof are substantially
centered on the axis "A" of the closure cup 44 and the outlet 42a is
positioned to
supply pressurized air into the fluid inlet tube 26.
[0072] As will be described, preferably, a hollow cylindrical centering or
alignment stem 74 is secured to the base member 52 and projects therefrom, the
stem aligned with the axis "A". The stem 74 has a rearward end threadably
connected to the outlet.42a and a forward end portion that is coaxially
inserted
into the fluid passage 26b of the inlet tube 26 and pass pressurized air from
the
supply line 20 directly into the fluid chamber 16.
[0073] The captivating end plate 50 comprises a hat shaped donut that
includes an annular ring plate 49, an annular ring sleeve 51, and a
cylindrical
central opening 53 extending therethrough. The ring plate 49 has upper and
lower faces 49a and 49b and an outer circumferential wall 49c. The outer
circumferential wall 49c of the end plate 50 and the interior forward end 54b
of
the cup sidewall 54 are provided with mating thread portions to enable the end
plate 50 to removably threadably connect to the closure cup 44, wherein to
captivate - the sealing assembly 48 in the receptacle 46. When connected, the
lower face 49b of the ring plate 49, at least in part, is juxtaposed against
the
upper end 56f of the bladder seal 56.
[0074] Further, to assist in connecting the ring plate 49 to the closure cup
44, a series of spanner holes 49d are provided equiangularly about the upper
face
26
CA 02624429 2008-03-07
49a for gripping by a spanner wrench wherein to rotate the end plate 50
clockwise and/or counterclockwise, depending on the thread sense and whether
the end plate 50 is being mounted to or removed from the closure cup 44. The
spanner wrench is not shown as being conventional and understood by those
skilled in the art.
I00751 The ring shaped sleeve 51 extends from the lower face 49b and has
a cylindrical outer wall 51a and terminates in a distal end face 51b. The
sleeve
51 is coaxially inserted into the receptacle 46 and into a central cylindrical
passage formed by the cylindrical inner wall 59 of an intermediate seal ring
58 in
the seal assembly 48. When the sleeve 51 is so fitted, the outer wall 51a
thereof
is juxtaposed, at least in part, with an upper annular end portion of the
inner
wall 59 of the seal ring 58 and the end face 51b is snugly juxtaposed atop the
distal or upper end face 56f of the bladder seal 56. Following the sealing
operation, the axial end faces 56f and 56r of the bladder seal 56 may be
forced
apart and the upper end may engage the end face 51b.
[00761 The central opening 53 extends between the upper face 49a of the
ring plate 49 and the distal lower end face 51b of the ring sleeve 51, the
opening
being coaxially centered with the axis "A" when the end plate 50 is connected
to
the closure cup 44. The opening or passage 53 is formed by and includes an
upper passage wall 53a, which is disposed, at least in part, in the ring plate
49
and opens on the upper face 49a, and a lower passage wall 53b, which is
disposed, at least in part, in the ring sleeve 51 and opens on the lower end
face
51b. The upper passage wall 53a is generally frusto-conical and tapers
inwardly
27
CA 02624429 2008-03-07
from the upper face 49a and terminates on the lower passage wall 53b. The
frusto-conical wall enables the leak check module 30 to accommodate an outward
radial extension (i.e., dimension) of the limit shoulder 29 found on some
inlet
tubes 26. The interior lower passage wall 53b is generally cylindrical and the
same diameter as the inner wall 56b of the bladder seal 56.
[0077] Referring to FIGS. 2 and 4, the sealing assembly 48 comprises the
cylindrical inner bladder seal 56, a generally cylindrical intermediate seal
activating ring 58, and a generally cylindrical outer packing ring 60. These
components 56, 58 and 60 are assembled together to form a unit that is nested
inside the receptacle 46 and captivated'therein by the end plate 50.
[0078] The individual components 56, 58, and 60 of the sealing assembly
48 could be described as a sleeve, a tube, and like terms. As will be
understood,
whatever the term, these components are comprised of materials that range from
relatively rigid (the outer packing ring 60) and semi-rigid or resilient (the
intermediate activating ring 58), which generally maintain shape, and
compressible (the bladder seal 56), which changes shape to form a fluid seal
about the inlet tube 26. For example, the packing ring 60 may be comprised of
a
metal, such as steel or aluminum. The activating ring 58 may be comprised of a
resilient polymer that may yield under pressure.
[0079] Preferably, the bladder seal 56 is comprised of a material that will
yield and compress. According to this invention, the bladder seal 56 is
comprised
of an elastomer, such as rubber or other suitable material capable of forming
a
fluid sealing relationship.
28
CA 02624429 2008-03-07
[0080] When the sealing assembly 48 is mounted within the receptacle 46,
the inner bladder seal 56, the intermediate activating ring 58, and outer
packing
ring 60 have respective cylindrical inner and outer walls generally coaxially
centered about the geometrical axis "A". The packing ring 60 is captivated in
encircling relation with and about the outer wall of the activating seal ring
58.
The outer wall of the packing ring 60 faces radially outward and is in
juxtaposed
relation with the non-threaded portion of the interior sidewall 54a.
[0081] The bladder seal 56 is generally cylindrical and has outer and inner
walls 56a and 56b adapted to centered coaxially on the central geometric axis
"A"
and forward and rearward ends 56f and 56r. The inner wall 56b is adapted to
receive and encircle the inlet tube 26.
[0082] In use, under the force of pressurized air, the bladder seal 5~6 is
adapted to compress radially inwardly, wherein the inner wall 56b thereof
compresses about and forms an airtight fluid seal about the exterior periphery
of
the inlet tube 26.
[0083] Referring to FIG. 6, the inner wall 56b of the bladder seal 56 is
shown positioned about the exterior cylindrical wall portion 26c of the inlet
tube
26 with the rearward end 56r juxtaposed with the radial end wall 27b formed by
the rearward end of the shaped rib 27 and the forward end 56f juxtaposed
against the end face 51b.
[0084] The intermediate activating seal ring 58 is generally cylindrical in
form and includes outer and inner walls 57 and 59 and forward and rearward
ends 58f and 58r. The outer wall 57 is stepped and includes forward and
29
CA 02624429 2008-03-07
rearward annular ribs 57f and 57r, respectively, proximate to the forward and
rearward ends 58f and 58r, and a generally cylindrical annular recess 57c,
which
recess extends generally coaxially between the ribs 57f and 57r. The inner.
wall
59 is generally cylindrical and adapted to be snugly juxtaposed in encircling
relation about and around the outer wall 56a of the bladder seal 56.
[0085] The activating seal ring 58 is comprised of a semi-rigid material
that is resilient and will yield under pressure, such as polymer. Importantly,
the
material is not fully rigid, wherein to maintain a generally cylindrical
shape, but
is sufficiently resilient or elastic, in order to yield under the force of
pressurized
air, or an inward circumferential force placed therearound. This inward force
on
the seal ring 58 causes a reduction in diameter of a central annular band or
portion of the wall thereof, causing the wall portion of the ring 58 to
contract
circumferentially inwardly, around, and against the bladder seal 56, causing
the
diameter of the bladder seal to reduce in diameter and compress about the tube
26. This diameter change effects an air sealing arrangement around and with
the exterior forward end portion of the inlet tube 26.
[0086] The outer packing ring 60 is of a lightweight rigid material, such as
aluminum, generally cylindrical, and includes forward and rearward ends 60f
and 60r. The outer wall 61 is stepped and includes forward and rearward
annular ribs 61f and 61r, proximate the respective ends 60f and 60r, and a
generally cylindrical annular recess 61c, which recess extends between the
ribs
61f and 61r. The inner wall 63 is similar to the outer wall, is stepped, and
includes forward and rearward annular ribs 63f and 63r and a generally
CA 02624429 2008-03-07
cylindrical annular recess 63c, which recess extends between the ribs 63f and
63r.
[0087] Referring to FIG. 3,the outer packing ring 60 and intermediate seal
ring 58 are shown positioned to form a support subassembly "S" with one
another.
[0088] Referring to FIG. 4, the sealing assembly 48 is shown positioned for
assembly in the receptacle 46 of the closure cup 44; showing the packing ring
60
and intermediate seal ring 58 having been formed into the support subassembly
Sõ
[0089] The outer packing ring 60 is snugly seated within the annular
recess 57c of the intermediate seal ring 58. So seated, the stepped inner wall
63
and annular recess 63c of the packing ring 60 are juxtaposed with the annular
recess 57c of the seal ring 58, and the forward and rearward ends 60f and 60r
of
the packing ring are fitted against the ribs 57f and 57r. The outer wall 61
and
annular recess 61c of the packing ring 60 are juxtaposed with the interior
sidewall 54a of the cup wall 54.
[0090] Importantly, and critical to this invention, a plurality of apertures
or holes or passages 62 extend radially through the cylindrical wall 61 of the
packing ring 60 and between the annular recesses 61c and 63c. In the
embodiment illustrated, eight cylindrical holes 62 of circular shape are
arranged
generally equiangularly around the central wall 61 of the packing ring 60.
[0091] The holes 62 are in fluid communication with the fluid passage 410
and operate to pass high-pressure air radially inwardly through the packing
ring
31
CA 02624429 2008-03-07
60, against the seal ring 58. The pressure is sufficient to force the wall of
the
seal ring inwardly against the bladder seal 56 and the bladder seal into
compressed relation against the inlet tube 26.
[0092] In this regard, pressurized air is passed vertically from the fluid
conduit 40 into the recess 68, upwardly and about the exterior of the packing
ring 60 and into the annular recess 61c. The annular recesses 61c and 63c
provide an annular air passage on each side of the packing ring 60 to receive
and
circumferentially distribute and communicate pressurized air 360 about the
packing ring.
[0093] Air from the passage 40 is then circumferentially circulated and
uniformly distributed 360 around the recess 61c, whereupon the air is
radially
passed through the holes 62 and into the annular recess 63c, and circulated
and
uniformly distributed 360 about a central annular wall portion of the
resilient
intermediate seal ring 58.
[0094] The central annular wall portion of the resilient seal ring 58 is
compressed radially inwardly against a corresponding central annular wall
portion of the bladder seal 56. This inward radial pressure forces the central
wall portion of the bladder seal 56 radially inwardly and into a compressed
sealed relation about the exterior surface 26c of the inlet tube 26.
[0095] The annular recesses 61c and 63c and the holes 62 ensure that a
substantially uniform pressure will compress the central annular wall portions
of
the seal ring 58 and bladder seal 56 radially inwardly. That is, the diameters
of
each are generally uniformly reduced.
32
CA 02624429 2008-03-07
[0096) Referring to FIGS. 4, 5, and 6, the packing ring 60 is shown when
assembled with the intermediate seal ring 58. The packing ring 60 is snugly
interfit and seated within the annular recess 57c and extends between the ribs
57f and 57r of the seal ring or sleeve 58. In FIG. 6, in use, the outer wall
61 and
associated ribs 61f and 61r of the packing ring 60 and associated ribs 57f and
57r
of the seal ring or sleeve 58 are juxtaposed against the interior wall 54a of
the
cup wal144.
[0097) A cylindrical ring shaped support 64 projects upwardly from the, end
wall 52b at the bottom of the receptacle 46 and includes cylindrical outer and
inner walls 64a and 64b, which are coaxially disposed relative to the axis "A"
and
the sidewall 54a of the closure cup 44. The support 64 terminates in an end
face
64c for supporting and positioning the bladder seal 56 in spared relation to
the
end wall 52b. The inner wall 64b of the support 64 and the end wall 52b of the
base member 52 cooperate to form a central cup shaped recess 66 at the bottom
of the receptacle 46. The outer wa1164a of the support 64, the sidewall 54a of
the
closure cup 44, and the end wall 52b cooperate to form an annular recess or
air
space or cavity 68 at the bottom of the receptacle 46, and at the junction
between
the sidewall 54 and endwall 52 of the cup 30.
[0098] The cylindrical side wall 54a is stepped, proximate to the outer
annular recess or air cavity 68, and includes a cylindrical shoulder 70 of
reduced
diameter, the shoulder extending upwardly from the end wall 52b and
terminating in an annular end face 72. The- end face 72 is spaced below the
plane of the end face 64c of the support 64, which forms a stop that engages
the
33
CA 02624429 2008-03-07
rearward end 58r of the intermediate seal ring 58 and defines a downward limit
on the seal ring 58 relative to the receptacle 46.
[0099] The shoulder 70, in combination with the seal ring 58, cooperates to
support and position the packing ring 60 above the end wall 52b and atop the
outer annular recess or cavity.68. The outer diameters of the ribs formed at
the
opposite axial ends of the seal and packing rings 58 and 60 are slightly less
than
the inner diameter of the side wall 54a, such that a slight cylindrical gap or
annular separation is provided between the side wall 54a when the support
assembly "S" is supported atop the shoulder 70. The shoulder 70, in part,
forms
the annular recess 68 at the junction between the sidewall and the base
member.
The opening 40a supplies pressurized air to the annular recess 68, upwardly to
the lower or rearward end of the sealing assembly 48 and into the outer
annular
recess 61c around the center of the packing ring 60, wherein to distribute the
pressurized air 360 about the annular recess 61c, through the holes 62 of the
packing ring 60, and into and 360 about the inner annular recess 63c of the
packing ring 60.
[00100] Preferably and according to this embodiment of the invention, the
hollow tubular centering tube or stem 74 is centrally mounted in the
receptacle
46 for conducting pressurized air from the passage 42 into the inlet tube 26.
The
centering tube 74 is axially elongated and has a rearward end 74r, a
cylindrical
forward end 74f, and a central passage 74c that extends between the opposite
ends 74f and 74r. The rearward end 74r is provided with mating thread and
threadably removably connected to the threaded bore formed at the opening 42a
34
CA 02624429 2008-03-07
of the air passage 42. The forward end 74f is adapted to be coaxially inserted
into the interior passage 26b of the fluid inlet tube 26. Preferably, the
forward
end 74f is dimensioned to extend axially forward of the forward end 54a of the
closure cup 44 and has a diameter slightly less than the interior diameter of
the
passage 26b of the inlet tube 26.
[00101] The centering tube 74 provides several functions. First and
foremost, the centering tube 74 ensures that pressurized air is directly
delivered
into the inlet tube 26 of the pump housing 24 being tested for fluid leakage.
Second, in close cramped or dimly lit working areas, configuring the forward
end
74f of the tube 74 to project outwardly from the forward end of the closure
cup 44
enables a worker to more rapidly position the closure cup 44 relative to the
inlet
tube of the work piece and center the centering tube 74 for coaxial insertion
into
the inlet tube 26. Further, the axially elongated forward end portion of the
tube
74 is toleranced to provide a coaxial clearance interfitment with the interior
wall
of the inlet tube 26 and stability to the connection by inhibiting off-axis
wobble.
[00102] The forward and rearward ends 58f and 58r of the intermediate seal
ring or sleeve 58 are sandwiched between and positioningly engaged by the end
face or stop 72 at the end of the annular shoulder 70 in the annular recess 66
and the end face 51b of the sleeve 51 on the captivating end plate 50. A-s
noted,
the forward and rearward ends 56f and 56r of the bladder seal 56 are
sandwiched between and positioningly engaged by the upper end face 64c of the
support 64 and the lower face 49b of the end plate 49.
CA 02624429 2008-03-07
[00103] Desirably, this engagement of the support components 58 and 60 of
the sealing assembly 48 and arrangement in the cup 30 inhibits inward radial
collapse of the central annular portion of the seal ring 58 when acted upon
and
forced radially inwardly by pressure from the apertures 62 in the packing ring
60. Additionally, stiffness of the seal ring or sleeve 58 is such that the
resilient
polymeric material yields under the "ring of pressure" thereabout and the
central
wall portion thereof provides an annular band that deforms radially inwardly
and against the bladder seal 56 to compress an annular band of the elastomeric
material of the bladder seal 56 against the inlet tube 26.
[00104] In use, the valves 36 and 38 are initially in a closed position,
wherein there is no fluid communication between the source 14 and the pump
housing 34 to be tested. The leak check module 30 is brought into position
with
the inlet tube 26 and the centering stem 74 of the closure cup 44 centered
with
the inlet tube 26, such as by the outwardly extended forward end 74f of the
stem
74 being brought into engagement with the free end 26a of the inlet tube 26.
The
forward end 74f of the stem 74 is inserted into the passage 26b of the tube 26
and
the tube end face 26a brought into engagement with the end wall 52b at the
bottom of the receptacle 46.
[00105] Once the centering stem 74 is centered in the passage 26b, the
check valve 36 in the handle 28 is opened. Pressurized air is passed -from the
supply line 18, through the fluid conduit 32 in the handle 28, through the
fluid
passage 40 and into the opening 40a in the annular recess 68, and into the
outer
annular recess 61c around the packing ring 60. The pressured air is then
for.ced
36
CA 02624429 2008-03-07
through the apertures 62 and into and around the inner annular recess 63c,
whereupon the seal 58 is compressed inwardly against the bladder 56, which in
turn compresses about the tube 26 and forms a fluid tight fluid seal
thereabout.
[00106] The pressure gauge 22a monitors the pressure supplied to form a
pressure seal with the outer, periphery of the inlet tube 26. When the
predetermined pressure is achieved, the valve 36 is closed and the pressure
maintained.
[00107] The valve 38 is opened, whereupon pressurized air passes from the
supply line 20, through the fluid conduit 34 in the handle 28, through the
fluid
passage 42 and the center passage 74c in the centering stem 74, and into the
chamber 24. The pressure gauge 22b monitors the pressure supplied to the
chamber 24. When the chamber 24 reaches a predetermined pressure, the valve
38 is closed and the chamber maintained at the preset level.
[00108] The read out gage 22c of the monitoring apparatus 22 monitors the
pressure in the chamber 24 'and provide a visual read out of a parameter of
interest, such as any drop in the chamber pressure measured by a predetermined-
time interval, or the chamber pressure. A drop in the pressure monitored
indicates that a leak is present in the pump housing.
[00109] In the embodiment illustrated, the bladder seal 56 compresses
about the inlet tube 26 at a location rearwardly of the shaped rib 27. In this
arrangement, the forward end 56f of the bladder 56 is proximal to the rearward
end face 27b of the shaped shoulder 27 to inhibit blow off of the leak check
module 30 from sealed engagement with the inlet tube 26.
37
CA 02624429 2008-03-07
[00110] Additional preferred embodiments of leak check modules according
to this invention are configured for use in leak testing fluid apparatus
having an
inlet or outlet that is much greater in diameter than that of the inlet tube
26
described herein above and thus these embodiments of leak check modules do not
include a centering stem 74. Illustrative of such fluid apparatus to be tested
for
leakage are the turbine and compressor unit of an automobile.
[00111] Turning to FIGS. 7 and 8, leak check modules 130 and 230 are
shown positioned for connection to the inlet and outlet of a turbine and
compressor units 112 and 212 of an automobile. The components of the leak
check modules and the connection structure of the unit to be tested for
leakage
are similar to that described herein above in relation to the leak testing of
the
water pump 12.
[00112] Additionally, in use, the leak check modules 130 and 230 are not
hand held but mounted to a robot (not shown). The robot sequentially controls
the position of the leak check module(s) and the pressure supplied to the
modules(s) as the units being tested are advanced along an assembly line.
[00113] As described above, regarding the leak check module 30, the outer
diameter of the stem 74 may be about 1 1/4 inch, and be adapted to clearance
fit
into the passage of the inlet tube 26, the inner diameter of the bladder 56
may be
about 1 7/8 inches, and seal about the inlet tube, and the inner diameter of
the
closure cup 44 may be about 2 5/8 inches. In contrast, in the leak check
modules
130 and 230, the inner diameter of the bladder 156 and 256 may be about 4 1/
inch, and the inner diameter of the cup 144 and 244 may be about 4 7/8 - 5.0
38
CA 02624429 2008-03-07
inches. In each case, however, the bladder seal in the closure cups 44, 144,
and
244, respectively, may be about 1/4 inch thick.
[00114] Turning to FIG. 7, a leak check module 130 is positioned about the
inlet collar 126 to a compressor, generally indicated by the reference numeral
112. The inlet collar 126 is generally cylindrical, terminates in an end face
or
inlet 126a, has an interior passage 126b, and cylindrical outer -surface 126c.
Further, the inlet collar terminates in a shaped annular rib 127 having a
frusto=
conical surface 127a that expands radially outwardly from the surface 1226c, a
generally vertically disposed end face 127b, and a rounded crest 127c.
[00115] The leak check module 130 comprises a cylindrical -cup shaped
closure cup 144 having a receptacle 146, a sealing assembly 148 mounted in the
receptacle, and an end plate 150 for captivating the sealing assembly in the
receptacle, each generally component centered along a common central geometric
axis "A". The cup 144 includes a base member 152 and a cylindrical sidewall
154.
[00116] A cylindrical support 164 projects from the end wall 152 and is
coaxially centered in the receptacle. A continuous 360 annular recess or air
cavity 168 is formed at the bottom of the receptacle and between the end wall
152, the sidewall 154a, and the outer wall 164a of the support 164. An annular
shoulder 170 is formed in the recess and provides a stop 172 for positioning
the
sealing assembly, at least in part.
[00117] A fluid passage 140 extends through the base member 152 and, at
least in part, into the sidewall 154 and supplies pressurized air from the
source
39
CA 02624429 2008-03-07
of air pressure to an opening 140a that opens in the annular recess or air
cavity
168.
[00118] The sealing assembly 148 includes an outer packing ring 160, an
intermediate seal 158, and an inner bladder or seal 156, each generally
cylindrical and coaxially centered along the geometric axis of the module when
mounted into the receptacle thereof. The packing ring and seals 1,60, 158, and
160, respectively, are generally as described hereinabove and comprised of the
materials as described.
[00119] When the sealing assembly 148 is positioned inside the receptacle
146, the seal ring 158 is abutted against the stop 172 and the packing ring
160 is
snugly fit within the outer annular recess of the seal ring 158 in a manner as
described herein above. The inner wall of the bladder seal 156 is dimensioned
to
encircle the outer wall of the support 164 and the shaped end portion 127c of
the
inlet 126.
[00120] When the end plate 150 is threadably connected to the module 130,
the lower end faces 149a and 151b thereof, respectively, abut the forward end
158f of the seal ring 158 and the forward end 156f of the bladder seal 15'6.
[00121] The inlet collar 126 is inserted into the receptacle such the end face
126a thereof is abutted against the end face of the support 164. So
positioned,
the inner wall 156b of the bladder seal 156 completely encircles the shaped
rib
127.
[00122] As described above, pressure is supplied to the conduit or passage
140, that opens in the recess 168, whereupon air passes upwardly to the
packing
CA 02624429 2008-03-07
ring 160, into and 360 around the outer annular recess thereof, through the
openings 162, into and 360 around the inner annular recess thereof, and
against
the seal sleeve 158. This pressure forces the central annular wall portions of
the
seal sleeve 158 and bladder seal 156 radially inwardly and an annular wall
portion of the bladder seal 156 into 360 sealed relation with the exterior of
the
collar 126 and the shaped rib portion 127 thereof. Air is then passed through
the
center passage 142 to pressurize the interior chamber of the compressor under
test, in a manner similar to that described herein above.
[00123] Turning to FIG. 8, the leak check module 230 is positioned about
the outlet collar 226 of a compressor, generally indicated at 212. The outlet
collar 226 is generally cylindrical and terminates in an outlet or end face
226a.
The collar 226 has an outer periphery formed by a rib 227 having forward and
rearward end portions 227a and 227b and a medial crest 227c, the rearward end
portion 227b spaced rearwardly from the end face 226a.
[00124] The leak check module 230 is similar to that described for the
compressor inlet but differs in that the inner seal or bladder seal 256 of the
sealing assembly 248 thereof is cup-shaped and comprises a hollow cylindrical
sleeve or wall 256c, similar to that described above, and a generally planar
base
or seal plate 255. The seal plate 255 radiates inwardly from the rearward end
of
the sleeve 256c and forms a central opening. In use, the lower face of the
seal
plate is abutted against a central support 264 of the module 230.
[00125] The leak testing operation is as above described. Fluid pressure is
delivered through the base member and side wall 252 and 254, into the air
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CA 02624429 2008-03-07
passages 240 and 242 therein, into a continuous 360 annular recess or air
cavity
268 about the lower end of the support 264, which recess is in fluid
communication with the passage 240, upwardly, into and between the outer and
inner annular recesses and apertures 262 in the packing ring 260, whereupon
the intermediate seal ring 258 and inner bladder seal 256 are compressed
inwardly towards the center axis and about the shaped portion 227 of the
collar
226.
[00126] Although the invention has been described relative to specific
embodiments thereof, there are numerous variations and modifications that will
be readily apparent to those skilled in the art in light of the above
teachings. It
is therefore to be understood that, within the scope of the appended claims,
the
invention may be practiced other than as specifically described.
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