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Patent 2354217 Summary

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Claims and Abstract availability

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(12) Patent: (11) CA 2354217
(54) English Title: PLUG BYPASS VALVES AND HEAT EXCHANGERS
(54) French Title: ROBINETS DE DERIVATION A TOURNANT ET ECHANGEURS THERMIQUES
Status: Expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • F28F 27/02 (2006.01)
  • F16K 31/06 (2006.01)
  • F16K 31/64 (2006.01)
  • F16K 31/70 (2006.01)
(72) Inventors :
  • PINEO, GREGORY MERLE (Canada)
  • CHEADLE, BRIAN EDWARD (Canada)
(73) Owners :
  • DANA CANADA CORPORATION / CORPORATION DANA CANADA (Canada)
(71) Applicants :
  • LONG MANUFACTURING LTD. (Canada)
(74) Agent: RIDOUT & MAYBEE LLP
(74) Associate agent:
(45) Issued: 2007-02-13
(22) Filed Date: 2001-07-26
(41) Open to Public Inspection: 2003-01-26
Examination requested: 2003-12-23
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data: None

Abstracts

English Abstract

Bypass valves and heat exchangers employing same are shown where the bypass valves cause the flow through the heat exchangers to be short-circuited under certain temperature conditions. The heat exchangers are formed of stacked plate pairs or tubes having enlarged communicating distal end portions forming inlet and outlet manifolds. The bypass valves can be plugged in where desired between the enlarged distal end portions to produce bypass flow between the inlet and outlet manifolds. The bypass valves include a housing which can be brazed in place during brazing of the heat exchanger. The housing has inlet and outlet openings in communication with the respective inlet and outlet manifolds for bypass flow therebetween. A removable temperature responsive actuator is located in the housing for blocking and unblocking the bypass flow through the valve.


French Abstract

Robinets de dérivation à tournant et échangeurs thermiques, où les robinets de dérivation font en sorte que le débit à travers les échangeurs thermiques soit court-circuité sous certaines conditions de température. Les échangeurs thermiques sont formés de paires de plaques superposées ou de tubes dotés d'extrémités de communications distales élargies formant des distributeurs d'entrée et de sortie. Les robinets de dérivation peuvent être branchés aux endroits désirés entre les extrémités distales élargies pour dériver le débit entre les distributeurs d'entrée et de sortie. Les robinets de dérivation sont dotés d'une enceinte qui peut être fixée en place par brasure pendant la brasure de l'échangeur thermique. L'enceinte est dotée d'ouvertures d'entrée et de sortie en communication avec les distributeurs d'entrée et de sortie respectifs pour faire dériver le débit. Un actuateur rétractable thermo-réactif est installé dans l'enceinte afin de bloquer et débloquer le débit de dérivation à travers le robinet.

Claims

Note: Claims are shown in the official language in which they were submitted.



-11-


Claims:

1. A bypass valve, for use with a heat exchanger of the type having a
plurality of
tubular members, the tubular members having respective, adjacent, spaced-apart
wall portions defining flow openings therein for the flow of fluid between the
tubular
members, the bypass valve comprising:
a housing having a hollow plug portion with opposed plug walls defining
respective inlet and outlet openings in said plug walls,
the plug walls being adapted to be sealingly mounted between selected heat
exchanger adjacent, spaced-apart wall portions to allow bypass fluid flow from
one
selected wall portion flow opening to the housing inlet opening, and from the
housing
outlet opening to another selected wall portion flow opening;
the bypass valve housing also having an actuator portion located adjacent to
the plug portion; and
an actuator releasably mounted in the actuator portion and having a
reciprocating plunger extending into the plug portion to substantially block
and
unblock flow between said inlet and outlet openings.
2. A bypass valve as claimed in claim 1 wherein the actuator is a temperature
responsive actuator having a central shaft mounted in the housing actuator
portion
and a reciprocating barrel portion forming said plunger.
3. A bypass valve as claimed in claim 2 wherein the actuator is a thermal
motor
adapted to extend axially upon being heated to a predetermined temperature and
to
retract upon being cooled below said temperature.
4. A bypass valve as claimed in claim 2 wherein the housing actuator portion
includes a removable closure located remote from the plug portion, the
actuator
central shaft being attached to the removable closure.
5. A bypass valve as claimed in claim 3 or 4 and further comprising bias means
located in the housing for urging the actuator to retract and the plunger to
unblock
the flow through the bypass valve.


-12-


6. A bypass valve as claimed in claim 1 wherein the housing plug portion
opposed plug walls are flat, parallel side walls defining said inlet and
outlet openings.
7. A bypass valve as claimed in claim 6 wherein said side walls are spaced
apart
a predetermined distance so as to determine the spacing between adjacent heat
exchanger tubular members.
8. A bypass valve as claimed in claim 2 and further comprising a spring
located
in the housing actuator portion to urge the central shaft toward the housing
plug
portion.
9. A bypass valve as claimed in claim 4 and further comprising a spring
located
between the removable closure and the actuator central shaft to urge the
actuator
into the housing plug portion.
10. A bypass valve as claimed in claim 1 wherein the actuator includes a
solenoid
having a central actuator shaft attached to the plunger, the shaft extending
upon
energization of the solenoid, so that the plunger blocks flow between the
inlet and
outlet openings, and further comprising bias means for urging the actuator
shaft to
retract upon de-energization of the solenoid.
11. A bypass valve as claimed in claim 10 and further comprising a temperature
sensor electrically coupled to the solenoid for energization of the solenoid
when the
temperature of the fluid going to the heat exchanger reaches a pre-determined
temperature.
12. A bypass valve as claimed in claim 11 wherein the temperature sensor is a
thermistor mounted on the plunger.
13. A bypass valve as claimed in claim 12 and further comprising an electrical
control circuit mounted in the housing and electrically connected between the
thermistor and the solenoid for controlling the movement of the plunger in



-13-


accordance with the temperature sensed by the thermistor.
14. A heat exchanger comprising:
a plurality of tubular members having respective, adjacent, spaced-apart wall
portions defining flow openings in the wall portions for the flow of fluid
between the
tubular members;
a bypass valve including a housing having a hollow plug portion with opposed
plug walls defining respective inlet and outlet openings in said plug walls;
the plug walls being sealingly mounted between selected adjacent, spaced-
apart wall portions to allow bypass fluid flow from one selected wall portion
flow
opening to the housing inlet opening, and from the housing outlet opening to
another
selected wall portion flow opening;
the bypass valve housing also having an actuator portion located adjacent to
the plug portion; and
an actuator releasably mounted in the actuator portion and having a
reciprocating plunger extending into the plug portion to substantially block
and
unblock flow between said inlet and outlet openings.
15. A heat exchanger as claimed in claim 14 wherein the tubular members are
formed of plate pairs having enlarged distal end portions joined together to
form inlet
and outlet manifolds, the distal end portions of a selected plate pair in each
manifold
defining said spaced-apart wall portion flow openings, said plug walls being
spaced-
apart side walls defining said inlet and outlet openings and being joined
respectively
to said selected plate pair spaced-apart wall portions, so that fluid can flow
between
the inlet and outlet manifolds through the bypass valve when the flow through
the
bypass valve is unblocked.
16. A heat exchanger as claimed in claim 15 wherein said plug walls are spaced
apart a predetermined distance so as to determine the spacing between adjacent
heat exchanger tubular members.
17. A heat exchanger as claimed in claim 14 wherein the actuator is a
temperature responsive actuator having a central shaft mounted in the housing




-14-
actuator portion and a reciprocating barrel portion forming said plunger.
18. A heat exchanger as claimed in claim 17 wherein the actuator is a thermal
motor adapted to extend axially upon being heated to a predetermined
temperature
and to retract upon being cooled below said temperature.
19. A heat exchanger as claimed in claim 14 wherein the actuator includes a
solenoid having a central actuator shaft attached to the plunger the shaft
extending
upon energization of the solenoid, so that the plunger blocks flow between the
inlet
and outlet openings, and further comprising bias means for urging the actuator
shaft
to retract upon de-energization of the solenoid.
20. A heat exchanger as claimed in claim 19 and further comprising a
temperature sensor electrically coupled to the solenoid for activation of the
solenoid
when the temperature of the fluid going to the heat exchanger reaches a pre-
determined temperature.

Description

Note: Descriptions are shown in the official language in which they were submitted.


CA 02354217 2001-07-26
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PLUG BYPASS VALVES AND HEAT EXCHANGERS
This invention relates to heat exchangers, and in particular, to bypass
valves for bypassing or short-circuiting flow from the heat exchanger inlet to
the
heat exchanger outlet under conditions where the heat transfer function of the
heat exchanger is not required or is only intermittently required.
In certain applications, such as in the automotive industry, heat
exchangers are used to cool or heat certain fluids, such as engine oil or
transmission fluid or oil. In the case of transmission fluid, for instance, a
heat
exchanger is usually used to cool the transmission fluid. The heat exchanger
is
usually located remote from the transmission and receives hot transmission
fluid
from the transmission through supply tubing, cools it, and delivers it back to
the
transmission again through return tubing. However, when the transmission is
cold, such as at start-up conditions, the transmission oil is very viscous and
does not flow easily through the heat exchanger, if at all. In such cases, the
transmission can be starved of fluid and this may cause damage to the
transmission or at least erratic performance. Damage can also be caused to the
transmission if the quantity of fluid returned is adequate, but is over-cooled
by
the heat exchanger due to low ambient temperatures. In this case, water may
accumulate in the transmission fluid as a result of condensation (which
normally
would be vaporized at higher temperatures) and this may cause corrosion
damage or transmission fluid degradation.
In order to overcome the cold flow starvation problem, it has been
proposed to insert a bypass valve between the supply and return tubing to and
from the heat exchanger. This bypass valve may be temperature responsive so
that it opens causing bypass flow when the transmission fluid is cold, and it
closes to prevent bypass flow when the transmission fluid heats up to
operating
temperature. An example of such a bypass valve is shown in U.S. Patent No.
6,253,837 issued to Thomas F. Seiler et al. While this approach works
satisfactorily, the heat exchanger and bypass valve assembly becomes quite

CA 02354217 2001-07-26
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large and includes fluid inlet and outlet tubing that may not otherwise be
required.
In the present invention, the bypass valve can be incorporated as an
integral part of the heat exchanger as a plug-in item that can be located
anywhere desired between the inlet and outlet flow manifolds of the heat
exchanger.
According to one aspect of the invention, there is provided a bypass
valve for a heat exchanger including a plurality of parallel, tubular members
having adjacent wall portions defining flow openings in communication to form
flow manifolds. The bypass valve comprises a housing having a hollow plug
portion with opposed plug walls defining inlet and outlet openings therein,
the
plug walls being adapted to be sealingly mounted between selected adjacent
tubular member wall portions to allow fluid flow respectively between the flow
manifolds and the inlet and outlet openings. The housing also has an actuator
portion located adjacent to the plug portion. Also, an actuator is releasably
mounted in the actuator portion and has a reciprocating plunger extending into
the plug portion to block and unblock flow between the inlet and outlet
openings.
According to another aspect of the invention, there is provided a heat
exchanger comprising a plurality of parallel, tubular members having adjacent
wall portions defining flow openings in communication to form inlet and outlet
manifolds for the flow of fluid through the tubular members. A bypass valve
includes a housing having a hollow plug portion with opposed plug walls
defining inlet and outlet openings therein, the plug walls being sealingly
mounted between selected adjacent tubular member wall portions to allow fluid
flow respectively between the flow manifolds and the inlet and outlet
openings.
The housing also has an actuator portion located adjacent to the plug portion.
Also, an actuator is releasably mounted in the actuator portion and has a
reciprocating plunger extending into the plug portion to block and unblock
flow
between the inlet and outlet openings.

CA 02354217 2001-07-26
-3-
Preferred embodiments of the invention will now be described by way of
example, with reference to the accompanying drawings, in which:
Figure 1 is an elevational view of a heat exchanger having a preferred
embodiment of a bypass valve according to the present invention mounted
therein;
Figure 2 is an enlarged view of the portion of Figure 1 indicated by circle
2;
Figure 3 is a perspective view, partly broken away of the bypass valve of
Figure 2 shown in the closed position;
Figure 4 is a perspective view similar to Figure 3 but showing the bypass
valve in the open position;
Figure 5 is an elevational view similar to Figure 2, but showing another
preferred embodiment of a bypass valve according to the present invention, the
valve being shown partially in cross-section;
Figure 6 is an elevational view similar to Figure 2, yet showing another
preferred embodiment of a bypass valve according to the present invention, the
valve being shown in cross-section and in the closed position;
Figure 7 is an elevational view similar to Figure 6, but showing the
bypass valve of Figure 6 in the open position;
Figure 8 is a schematic view of a heat exchanger having multiple passes
and more than one bypass valve; and
Figure 9 is an elevational view of a portion of another preferred
embodiment of a heat exchanger and bypass valve according to the present
invention.
Referring firstly to Figures 1 and 2, a heat exchanger is generally
indicated by reference in 10, and a preferred embodiment of a bypass valve
according to the present invention is generally indicated by reference numeral
12. Heat exchanger 10 is formed of a plurality of parallel, spaced-apart,
tubular
members 14 preferably with enlarged distal end portions 16 that have adjacent
wall portions 17 defining flow openings (not shown) in communication. Tubular
members 14 are preferably formed of mating plate pairs with transversely

CA 02354217 2001-07-26
protruding cupped end portions to form these enlarged end portions 16 that
also
together form flow manifolds 19 and 21. However, tubular members 14 could be
formed of tubes with separate joined enlarged end portions 16, if desired.
Alternatively, tubular members of uniform width or thickness could be used, in
which case tubular spacers could be used between the tube ends in place of
enlarged distal end portions 16. If it is not necessary to space tubular
members
14 apart transversely, then such spacers would not be required. Yet another
possibility would be to use transversely orientated tubular manifolds 19 and
21
attached in communication with the ends of tubular members 14. For the
purpose of this disclosure, the term "distal end portions" is intended to
include
all of the above-mentioned tube member communicating wall structures.
Corrugated cooling fins 18 are located between the tubular members 14 where
the tubular members 14 are spaced apart transversely.
In the heat exchangers shown in Figures 1 and 2, the tubular members
14 are formed into two upper and lower groups separated by central back-to-
back dimpled plates 20 having offset end portions 22, 24. As seen best in
Figure 2, the space between offset end portions 22, 24 provides a location
where bypass valve 12 can be plugged into heat exchanger 10. Bypass valve
12 includes a hollow plug portion 26 located in this space, and which will be
described in further detail below.
As mentioned above, the enlarged distal end portions 16 have transverse
openings therethrough (not shown), so that the distal end portions 16 located
above bypass valve 12 are all in communication and form either an inlet or an
outlet manifold 19 depending on the direction in which fluid is to flow
through
heat exchanger 10. Similarly, the enlarged distal end portions 16 located
below
bypass valve 12 are all in communication and form a respective outlet or inlet
manifold 21. As seen best in Figure 1, an inlet or outlet fitting 28
communicates
with the enlarged distal end portions below it and an inlet or outlet fitting
30
communicates with the enlarged distal end portions above it. So, for example,
fluid entering inlet fitting 28 travels from right to left as shown in Figure
1
through all of the tubular members 14 located above dimpled plates 20, to a

CA 02354217 2001-07-26
-5-
similar left hand manifold formed by enlarged distal end portions 32, and then
downwardly through a cross-over fitting 34 into a left hand manifold in the
lower
section of heat exchanger 10 formed by enlarged distal end portions 32, and
then back to the right end and out through outlet fitting 30. Heat exchanger
10
is thus called a two-pass heat exchanger and can have any number of tubular
members 14 above or below the dimpled plates 20. In fact, there could just be
one tubular member 14 above or below dimpled plates 20, as illustrated in the
embodiment shown in Figure 9 and as described further below.
Heat exchanger 10 also has upper and lower dimpled plates 36. Suitable
mounting brackets 40 are attached to dimpled plates 36, 38 as are the inlet
and
outlet fittings 28, 30.
Referring next to Figures 3 and 4, bypass valve 12 includes a housing 42
having a hollow plug portion 26 with spaced-apart, opposed, flat, parallel
plug
side walls 43 defining transversely located inlet and outlet openings 44, 46
formed therein for the flow of fluid through plug portion 26 when valve 12 is
in
the open position as shown in Figure 4. Plug walls 43 are sealingly mounted
between selected adjacent tubular member wall portions 17 of the enlarged
distal end portions 16 of tubular members 14. The distal end portions 16 have
flat mating surfaces. The offset end portions 22 mate flush against their
adjacent
distal end portion flat surfaces and the flat housing side walls 43 mate flush
against the flat offset end portions 22. However, housing side or plug walls
43
would mate flush against the flat portions of distal end portions 16, if
dimpled
plates 22 were not used in heat exchanger 10. This mounting allows bypass
fluid flow directly between selected distal end portions 16, or respectively
between the flow manifolds 19 and 21 and the inlet and outlet openings 44 and
46, or between the inlet and outlet fittings 28, 30 when bypass valve 12 is
open.
Bypass valve side or plug walls 43 are spaced apart a predetermined distance
so as to determine the spacing between adjacent heat exchanger tubular
members, especially if dimpled plates 20 are not used.
Bypass valve housing 42 also has an actuator portion 48 located
adjacent to and communicating with plug portion 26. A temperature responsive

CA 02354217 2004-03-12
-6-
actuator 50 is located in housing 42. Actuator 50 has a central shaft 52
attached to a
removable closure 54 located remote from plug portion 26. Removable closure 54
has an O-ring seal 56 and is held in position by a split pin 58 passing
through
openings 60 in housing actuator portion 40 and a through hole 62 in closure
54.
Temperature responsive actuator 50 has a reciprocating barrel portion 64
which forms a plunger slidably located in housing plug portion 26 to block and
unblock flow between inlet and outlet openings 44, 46. A spring 66 is located
in
housing actuator portion 48 and bears against an annular shoulder 68 on barrel
64 to
act as bias means to urge the actuator 50 to retract so that barrel or plunger
64
unblocks the flow of fluid through inlet and outlet openings 44, 46 of bypass
valve 12,
when the actuator is not extended due to temperature, as described next below.
Temperature responsive actuator 50 is sometimes referred to as a thermal
motor and it is a piston and cylinder type device. Barrel or plunger 64 is
filled with a
thermal sensitive material, such as wax, that expands and contracts, causing
the
actuator to extend axially upon being heated to a predetermined temperature
and to
retract upon being cooled below this predetermined temperature. Where bypass
valve 12 is used in conjunction with an automotive transmission fluid or oil
cooler,
this predetermined temperature is about 80°C, which is the temperature
of the fluid
from the transmission when bypass flow is no longer required.
Referring next to Figure 5, another preferred embodiment of a bypass valve
according to the present invention is generally indicated by reference numeral
70.
Bypass valve 70 is similar to bypass valve 12 except that a sliding plate 72
bears
against central shaft 52 and a spring 74 is located in housing actuator
portion 48 to
urge central shaft 52 toward the housing plug portion 26. Spring 74 absorbs
any
pressure spikes or peeks that may occur in the inlet and outlet manifolds of
heat
exchanger 10. A notch 76 is formed in barrel 64 to allow the fluid to act
against the
end of barrel 64 and provide this pressure relief even when bypass valve 70 is
closed. A bleed hole through plunger or barrel 64

CA 02354217 2001-07-26
_7_
communicating with inlet opening 44 could also be used in place of notch 76
for
this purpose. Otherwise, bypass valve 70 is substantially the same as bypass
valve 12.
Referring next to Figures 6 and 7, another preferred embodiment of a
bypass valve according to the present invention is generally indicated by
reference numeral 80. In bypass valve 80, the temperature responsible actuator
50 includes a solenoid having a solenoid coil 82 and a central actuator shaft
84
attached to a plunger 86. Plunger 86 also has a notch or bleed hole 76 to
provide pressure spike relief when valve 80 is closed. Actuator shaft 84
extends upon energization of solenoid coil 82, so that plunger 86 blocks flow
between the housing inlet and outlet openings 44, 46. A spring 88 located in
housing plug portion 26 bears against plunger 86 to act as bias means for
urging the actuator shaft 84 to retract upon the energization of solenoid coil
82.
A temperature sensor 90 is attached to plunger 86 and is in the form of a
thermistor electrically coupled to solenoid coil 82 for actuation of the
solenoid
coil when the temperature of the fluid going through heat exchanger 10 reaches
a predetermined temperature. Temperature sensor 90 could be located
elsewhere in bypass valve 80, or even elsewhere in heat exchanger 10.
Preferably, temperature sensor 90 is electrically connected to an electrical
control circuit 92 mounted in housing actuator portion 48. Electrical control
circuit 92 is in turn is electrically connected to solenoid coil 82 for
controlling the
movement of plunger 86 in accordance with the temperature sensed by
temperature sensor 90. In this way, the opening of bypass valve 80 could be
controlled to provide variable opening, rather than a simple on or off, but
the
latter is also possible.
Referring next to Figure 8, a heat exchanger 100 is shown schematically
and it is like two heat exchangers 10 of Figure 1 mounted in series. Two
bypass
valves 102, 104 are used to provide thermal modulation of the fluid flowing
through the heat exchanger 100. Bypass valve 102 may have a predetermined
temperature set point or activation temperature, and bypass valve 104 may
have a somewhat higher temperature set point or activation temperature. Heat

CA 02354217 2002-05-02
_$_
exchanger 100 is a four pass heat exchanger having four groups or stacks 106,
108, 110 and 112 of tubular members.
Where both bypass valves 102 and 104 are open, such as during cold
flow operation, there is full fluid bypass from inlet fitting 28 to outlet
fitting 30.
Where bypass valve 102 is closed and valve 104 is open, such as during warm
up or an interim temperature of fluid flowing through heat exchanger 100,
there
would be fluid flow through the top two passes 106 and 108 of heat exchanger
100, but passes 110 and 112 would be bypassed through bypass valve 104.
Where the fluid reaches its hot operating temperature, both bypass valves 102
and 104 would close giving flow through all four passes 106, 108, 110 and 112
and no bypass flow at all. Additional multiples of passes and bypass valves
could be used in a single heat exchanger as well. Any of the types of bypass
valves described above could be used in heat exchanger 100.
Referring next to Figure 9, other preferred embodiments of a heat
exchanger 113 and a bypass valve 115 are shown. In bypass valve 115, inlet
and outlet openings 44, 46 are formed in opposed plug walls 114, 116 and this
shows that inlet and outlet openings 44, 46 can be located anywhere in plug
portion 26 as long as one of these openings is blocked when valve 115 is
closed. Otherwise, bypass valve 115 is substantially similar to or can
incorporate
the features of the bypass valves 12, 70 and 80 described above. In the
embodiment of Figure 9, plate 38 (which preferably is dimpled but may be flat)
and a bottom plate 118 (which may also be dimpled or flat), together form a
tubular member 120 which is one of the tubular members that make up heat
exchanger 113. Tubular member 120 is actually a bypass channel and has flow
openings 122 that communicate with the flow openings in the adjacent enlarged
distal end portions 16 of adjacent tubular member 14, and as such forms part
of
the inlet and outlet manifolds of heat exchanger 113. Instead of tubular
member
120, a regular tubular member 14 could be used in heat exchanger 113, if
desired. This would produce a full flood or single pass heat exchanger.
Tubular
members 14 may or may not have turbulizers in them or be made of dimpled
plates, but the bottom tubular member 120 likely would not be turbulized or
have
other types of flow augmentation, such as dimples.

CA 02354217 2002-05-02
_g_
In the assembly of heat exchangers 10, 100 and 113,-the various
components, such as the tubular members 14 or 120 and fins 18 are stacked
together along with dimpled plates 20, if desired, and upper and lower dimpled
plates 36, 38. Mounting plates or brackets 40 and inlet and outlet fittings
28, 30
can be preassembled to upper and lower dimpled plates 36, 38, or assembled
along with all of the other components. The housing 42 of the preferred bypass
valve 12, 70, 80 or 115 (without any other bypass valve components) is then
placed in the desired location in the heat exchanger and the entire assembly
is
brazed together in a brazing furnace. It will be appreciated that in the
preferred
embodiments, aluminum or a brazing-clad aluminum is used for most of the
parts of the heat exchangers, so that all of the parts can be brazed together
in a
brazing furnace. After this assembly is cooled, the desired actuator
components
of the bypass valves are inserted into housing 42 and the removable closures
54
are secured in position with split pins 58.
Having described preferred embodiments of the invention, it will be
appreciated that various modifications can be made to the structures described
above. For example, instead of using a thermal motor or solenoid type actuator
for the bypass valves, other devices could be used as well, such as a bi-
metallic
helix to move the barrel or plunger of the valve. The tubular members can also
have other shapes or configurations as well.
From the above, it will be appreciated that the bypass valves of the
present invention are in the form of plugs that can be plugged in at any
desired
location in the heat exchanger with a simple rearrangement of the location of
some components. The bypass valve housings actually act as a form of baffle
plate to intermittently block flow between manifold portions of the heat
exchangers. In fact, the bypass valves could be plugged in anywhere in the
heat
exchangers where it is desired to have bypass flow between the plate pairs or
tubes. The bypass valve housings are brazed in place along with all of the
other heat exchanger components. The actual valve elements in the actuators
are then removably or releasably located in the bypass valve housings to
complete the assembly. No external tubing or peripheral components are
required to make the actuator valves active.

CA 02354217 2001-07-26
-10-
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention without departing from the spirit or scope thereof. The
foregoing
description is of the preferred embodiments and is by way of example only, and
it is not to limit the scope of the invention.

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2007-02-13
(22) Filed 2001-07-26
(41) Open to Public Inspection 2003-01-26
Examination Requested 2003-12-23
(45) Issued 2007-02-13
Expired 2021-07-26

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Application Fee $300.00 2001-07-26
Registration of a document - section 124 $100.00 2002-05-02
Maintenance Fee - Application - New Act 2 2003-07-28 $100.00 2003-04-09
Registration of a document - section 124 $50.00 2003-06-20
Request for Examination $400.00 2003-12-23
Maintenance Fee - Application - New Act 3 2004-07-26 $100.00 2004-07-02
Maintenance Fee - Application - New Act 4 2005-07-26 $100.00 2005-07-14
Maintenance Fee - Application - New Act 5 2006-07-26 $200.00 2006-03-30
Final Fee $300.00 2006-12-04
Maintenance Fee - Patent - New Act 6 2007-07-26 $200.00 2007-04-23
Maintenance Fee - Patent - New Act 7 2008-07-28 $200.00 2008-05-28
Maintenance Fee - Patent - New Act 8 2009-07-27 $200.00 2009-06-30
Maintenance Fee - Patent - New Act 9 2010-07-26 $200.00 2010-06-30
Maintenance Fee - Patent - New Act 10 2011-07-26 $250.00 2011-06-30
Maintenance Fee - Patent - New Act 11 2012-07-26 $450.00 2012-10-01
Maintenance Fee - Patent - New Act 12 2013-07-26 $250.00 2013-07-01
Maintenance Fee - Patent - New Act 13 2014-07-28 $250.00 2014-07-21
Maintenance Fee - Patent - New Act 14 2015-07-27 $250.00 2015-07-20
Maintenance Fee - Patent - New Act 15 2016-07-26 $450.00 2016-07-25
Maintenance Fee - Patent - New Act 16 2017-07-26 $450.00 2017-07-24
Maintenance Fee - Patent - New Act 17 2018-07-26 $450.00 2018-07-23
Maintenance Fee - Patent - New Act 18 2019-07-26 $450.00 2019-07-19
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
DANA CANADA CORPORATION / CORPORATION DANA CANADA
Past Owners on Record
CHEADLE, BRIAN EDWARD
LONG MANUFACTURING LTD.
PINEO, GREGORY MERLE
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Representative Drawing 2002-03-08 1 31
Cover Page 2003-01-02 1 62
Drawings 2002-05-02 9 237
Description 2002-05-02 10 504
Abstract 2001-07-26 1 24
Cover Page 2007-01-19 1 55
Description 2001-07-26 10 504
Claims 2001-07-26 4 148
Drawings 2001-07-26 9 337
Claims 2004-03-12 4 156
Claims 2005-07-25 4 174
Representative Drawing 2006-11-07 1 21
Description 2004-03-12 10 502
Correspondence 2001-08-23 1 24
Assignment 2001-07-26 2 90
Prosecution-Amendment 2002-05-02 16 543
Assignment 2002-05-02 4 157
Assignment 2003-06-20 4 195
Fees 2003-04-09 1 30
Prosecution-Amendment 2003-12-23 1 43
Prosecution-Amendment 2004-03-12 7 262
Fees 2004-07-02 1 36
Prosecution-Amendment 2005-03-10 2 41
Prosecution-Amendment 2005-07-25 6 241
Fees 2005-07-14 1 26
Fees 2006-03-30 1 26
Correspondence 2006-12-04 1 25
Fees 2007-04-23 1 29
Fees 2008-05-28 1 34
Correspondence 2008-08-19 1 16
Correspondence 2008-09-22 1 13
Fees 2008-08-27 2 37