U.S. patent number RE31,337 [Application Number 05/946,491] was granted by the patent office on 1983-08-09 for vehicle brake system.
This patent grant is currently assigned to Echlin Inc.. Invention is credited to George W. Stearns.
United States Patent |
RE31,337 |
Stearns |
August 9, 1983 |
Vehicle brake system
Abstract
A multi-axle vehicle brake system includes an air receiving
portion, a valve portion, an air storage portion and a brake
portion. The air receiving portion receives air from a supply
source. The valve portion is connected to the air receiving
portion. The storage portion includes a plurality of storage
reservoirs connected for receiving air from and communicating air
to the valve portion. The brake portion includes service and
parking brake actuating chambers mounted on each end of each axle.
Certain ones of the service brake actuating chambers are connected
for receiving air from one of the storage reservoirs. Others of the
service brake actuating chambers are connected for receiving air
from another of the storage reservoirs. Each of the parking brake
actuating chambers are connected for receiving air from either of
the storage reservoirs. .Iadd.
Inventors: |
Stearns; George W. (Florissant,
MO) |
Assignee: |
Echlin Inc. (Branford,
CT)
|
Family
ID: |
27092900 |
Appl.
No.: |
05/946,491 |
Filed: |
September 28, 1978 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
903886 |
May 8, 1978 |
|
|
|
Reissue of: |
637644 |
Dec 4, 1975 |
03992064 |
Nov 16, 1976 |
|
|
Current U.S.
Class: |
303/7 |
Current CPC
Class: |
B60T
13/268 (20130101); B60T 13/265 (20130101) |
Current International
Class: |
B60T
13/24 (20060101); B60T 13/26 (20060101); B60T
013/28 () |
Field of
Search: |
;303/7,9,13,26,29,63,64,85 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
School Bus Piping, Sealed Air Brakes, Inc., City of Industry,
Calif., Dec. 31, 1966, Specification, Mack Dual Circuit Air Brake
System, No. 2-73, MOS-122-T. .
Specification, International Truck Brake System. .
Specification, Bendix-Westinghouse Dual Air Brake System. .
Air Brake, W Series, 1975 Ford Truck Specification, pp. 179, 180.
.
Specification, Berg 1974, Air Brake System for 6.times.4 Tractors.
.
Specification, Berg 1974, Air Brake System for Semi-Trailers. .
Specification, FMV SS 121, Midland, Tractor-Trailer Air Brake
System Power Controls Division, Midland Ross Corp., 1973..
|
Primary Examiner: Reger; Duane A.
Attorney, Agent or Firm: Neuman, Williams, Anderson &
Olson
Parent Case Text
This is a division of reissue application serial no. 903,886, filed
May 8, 1978 which is, in turn, a reissue of U.S. Patent 3,992,064
filed Nov. 16, 1976. .Iaddend.
Claims
What is claimed is: .[.1. A vehicle brake system comprising:
an air receiving portion including means for receiving air from a
supply source;
a valve portion connected to the air receiving portion including a
first plurality of one-way check valve means separated for
independently operating on the air received and for securing the
air operated on from returning to the receiving portion;
a storage portion connected to the valve portion including a
plurality of storage means separated for independently receiving
the air from the first separated valve means, respectively, and for
storing the air received;
a second plurality of one-way check valve means, corresponding to
the first valve means, separated in the valve portion and
cooperatingly connected to the separated storage means,
respectively, for selecting air from one of the storage means, for
independently operating on the selected air, for securing the
selected air from returning to its respective storage means and for
further securing the selected air from paassing to another of the
storage means; and
a brake portion including service brake means connected for
receiving air from the storage means and also including parking
brake means connected for receiving the selected air from the
storage means..]. .[.2. The system of claim 1, and further
including:
pressure regulating valve means in the valve portion connected
between the air receiving portion and the storage portion for
permitting air above a predetermined pressure to pass
therethrough..]. .[.3. The system of claim 2, and further
including:
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake
means..]. 4. A vehicle brake system comprising:
an air receiving portion including means for receiving air from a
supply source;
a valve portion connected to the air receiving portion including a
first plurality of like valve means separated for independently
operating on the air received and for securing the air operated on
from returning to the receiving portion;
a storage portion connected to the valve portion including a
plurality of storage means separated for independently receiving
the air from the first separated valve means, respectively, and for
storing the air received;
a second plurality of like valve means, corresponding to the first
valve means, separated in the valve portion and cooperatingly
connected to the separated storage means, respectively, for
selecting air from one of the storage means, for independently
operating on the selected air, for securing the selected air from
returning to its respective storage means and for further securing
the selected air from passing to another of the storage means;
a brake portion including service brake means connected for
receiving air from the storage means and also including parking
brake means connected for receiving the selected air from the
storage means;
pressure regulating valve means in the valve portion connected
between the air receiving portion and the storage portion ofr
permitting air above a predetermined pressure to pass
therethrough;
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake means; and
further valve means in the valve portion corresponding to the like
valve means connected between the air receiving portion and the
brake operating
valve means bypassing the pressure regulating valve means. .[.5. A
towed vehicle brake system comprising:
an air receiving portion including means for receiving air from a
supply source;
a valve portion connected to the air receiving portion including a
plurality of one-way check valve means separated for independently
operating on the air received and for securing the air operated on
from returning to the receiving portion;
a storage portion connected to the valve portion including a
plurality of storage means separated for independently receiving
the air from the first separated valve means, respectively, and for
storing the air received;
other one-way check valve means in the valve portion cooperatingly
connected to the separated storage means for selecting air from one
of the storage means and for securing the selected air from passing
to another of the storage means; and
a brake portion including service brake means connected for
receiving air from the storage means and also including parking
brake means connected for receiving the selected air from the
storage means..]. .[.6. The system of claim 5, and further
including:
pressure regulating valve means in the valve portion connected
between the air receiving portion and the storage portion for
permitting air above a predetermined pressure to pass
therethrough..]. .[.7. The system of claim 6, and further
including:
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake
means..]. 8. A towed vehicle brake system comprising:
an air receiving portion including means for receiving air from a
supply source;
a valve portion connected to the air receiving portion including a
plurality of like valve means separated for independently operating
on the air received and for securing the air operated on from
returning to the receiving portion:
a storage portion connected to the valve portion including a
plurality of storage means separated for independently receiving
the air from the first separated valve means, respectively, and for
storing the air received;
other valve means in the valve portion cooperatingly connected to
the separated storage means for selecting air from one of the
storage means and for securing the selected air from passing to
another of the storage means;
a brake portion including service brake means connected for
receiving air from the storage means and also including parking
brake means connected for receiving the selected air from the
storage means;
pressure regulating valve means in the valve portion connected
between the air receiving portion and the storage portion for
permitting air above a predetermined pressure to pass
therethrough;
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake means; and
further valve means in the valve portion corresponding to the like
valve means connected between the air receiving portion and the
brake operating
valve means bypassing the pressure regulating valve means. .[.9. A
vehicle brake system comprising:
an air receiving portion including means for receiving air from a
supply source;
a valve portion connected to the air receiving portion including a
first plurality of one-way check valve means separated for
independently operating on the air received and for securing the
air operated on from returning to the receiving portion;
a storage portion connected to the valve portion including a
plurality of storage means separated for independently receiving
the air from the first separated valve means, respectively, and for
storing the air received;
a second plurality of one-way check valve means, corresponding to
the first valve means, separated in the valve portion and
cooperatingly connected to the separated storage means,
respectively, for selecting air from one of the storage means, for
independently operating on the selected air, for securing the
selected air from returning to its respective storage means and for
further securing the selected air from passing to another of the
storage means; and
a brake portion including service brake means, ones of the service
brake means connected for receiving air from one of the storage
means, another of the service brake means connected for receiving
air from another of the storage means and also including parking
brake means connected for receiving the selected air from the
storage means..]. .[.10. A vehicle brake system comprising:
an air receiving portion including first and second means for
receiving air from a supply source;
a valve portion connected to the air receiving portion including
first and second one-way check valve means separately connected for
unidirectionally passing air there-through from the first ar
receiving means;
a storage portion connected to the valve portion including first
and second storage means separately connected for receiving air
from the first and second valve means, respectively, and for
storing the air received;
third and fourth one-way check valve means, corresponding to the
first and second valve means, separately and cooperatingly
connected to the first and second storage means, respectively, for
selecting air from one of the storage means, for unidrectionally
passing the selected air there-through, for securing the selected
air from returning to its respective storage means and for further
securing the selected air from passing to the other of the storage
means; and
a brake portion including service brake means, ones of the service
brake means connected for receiving air from the first storage
means, others of the service brake means connected for receiving
air from the second storage means and also including parking brake
means connected for receiving the selected air from the storage
means..]. .[.11. The system of claim 10, and further including:
pressure regulating valve means in the valve portion connected
between the first means for receiving ar and the storage portion
for permitting air above a predetermined pressure to pass
therethrough..]. .[.12. The system of claim 11, and further
including:
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake
means..]. 13. A vehicle brake system comprising:
an air receiving portion including first and second means for
receiving air from a supply source;
a valve portion connected to the air receiving portion including
first and second like valve means separately connected for
unidirectionally passing air therethough from the first air
receiving means;
a storage portion connected to the valve portion including first
and second storage means separately connected for receiving air
from the first and second like valve means, respectively, and for
storing the air received;
third and fourth like valve means, corresonding to the first and
second valve means, separately and cooperatingly connected to the
first and second storage means, respectively, for selecting air
from one of the storage means, for unidirectionally passing the
selected air therethrough, for securing the selected air from
returning to its respective storage means and for further securing
the selected air from passing to the other of the storage
means;
a brake portion including service brake means, ones of the service
brake means connected for receiving air from the first storage
means, others of the service brake means connected for receiving
air from the second storage means and also including parking brake
means connected for receiving the selected air from the storage
means;
pressure regulating valve means in the valve portion connected
between the first means for receiving air and the storage portion
for permitting air above a predetermined pressure to pass
therethrough;
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake means; and
fifth valve means in the valve portion corresponding to the like
valve means connected between the first means for receiving air and
the brake operating valve means bypassing the pressure regulating
valve means. .[.14. A towed vehicle brake system comprising:
an air receiving portion including first and second means for
receiving air from a supply source;
a valve portion connected to the air receiving portion including
first and second one-way check valve means separately connected for
unidirectionally passing air therethrough from the first air
receiving means;
a storage portion connected to the valve portion including first
and second storage means separately connected for receiving air
from the first and second valve means, respectively, and for
storing the air received;
other one-way check valve means in the valve portiion cooperatingly
connected to the first and second storage means for selecting air
from one of the storage means and for securing the selected air
from passing to the other of the storage means; and
a brake portion including service brake means, ones of the srvice
brake means connected for receiving air from the first storage
means, others of the service brake means connected for receiving
air from the second storage means and also including parking brake
means connected for receiving the selected air from the storage
means..]. .[.15. The system of claim 14, and further including:
pressure regulating valve means in the valve portion connected
between the first air receiving means and the first and second
storage means for permitting air above a predetermined pressure to
pass therethrough..]. .[.16. The system of claim 15, and further
including:
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake
means..]. 17. A towed vehicle brake system comprising:
an air receiving portion including first and second means for
receiving air from a supply source;
a valve portion connected to the air receiving portion including
first and second like valve means separately connected for
unidirectionally passing air therethrough from the first air
receiving means;
a storage portion connected to the valve portion including first
and second storage means separately connected for receiving air
from the first and second like valve means, respectively, and for
storing the air received;
other valve means in the valve portion cooperatingly connected to
the first and second storage means for selecting air from one of
the storage means and for securing the selected air from passing to
the other of the storage means;
a brake portion including service brake means, ones of the srvice
brake means connected for receiving air from the first storage
means, others of the service brake means connected for receiving
air from the second storage means and also including parking brake
means connected for receiving the selected air from the storage
means;
pressure regulating valve means in the valve portion connected
between the first air receiving means and the first and second
storage means for permitting air above a predetermined pressure to
pass therethrough;
brake operating valve means in the valve portion connected for
receiving the selected air and for supplying the selected air to
the parking brake means; and
further valve means in the valve portion corresponding to the like
valve means connected between the first means for receiving air and
the brake operating valve means bypassing the pressure regulating
valve means. .[.18. A vehicle service and parking brake system
comprising:
first and second air receiving means for receiving air from a
supply source;
first and second air storage means connected for receiving air from
the first air receiving means;
first and second unidirectional valve means connected to the first
air receiving means for permitting air to pass therethrough to the
first and second storage means, respectively;
first and second brake operating valve means connected for
receiving air from the first and second storage means,
respectively, and for supplying air from the storage means to the
service brake means,
third and fourth unidirectional valve means connected to the first
and second storage means, respectively, cooperating for selecting
air from one of the storage means and for securing the selected air
from passing to the other of the storage means; and
third brake operating valve means connected for receiving the
selected air, and for supplying the selected air to the parking
brakes..]. .[.19. A vehicle service and parking brake system
comprising:
first and second air receiving means for receiving air from a
supply source;
first and second air storage means connected for receiving air from
the first air receiving means;
pressure regulating valve means connected between the first air
receiving means and the first and second air storage means for
permitting air above a predetermined pressure to pass
therethrough;
first and second unidirectional valve means connected to the first
air receiving means for permitting air to pass therethrough to the
first and second storage means, respectively;
first and second brake operating valve means connected for
receiving air from the first and second storage means,
respectively, for receiving air from the second air receiving means
and for supplying air from the storage means to the service brake
means;
third and fourth unidirectional valve means connected to the first
and second storage means, respectively, cooperating for selecting
air from one of the storage means and for securing the selected air
from passing to the other of the storage means; and
third brake operating valve means connected for receiving the
selected air
and for supplying the selected air to the parking brake means..].
.[.20. The system of claim 19, and further including:
fifth unidirectional valve means in the valve portion connected for
passing air therethrough from the first air receiving means to the
third brake operating valve means bypassing the pressure regulating
valve means..]. .Iadd. 21. A vehicle service and parking brake
system comprising:
first and second air receiving means for receiving air from a
supply source;
first and second air storage means connected for receiving air from
the first air receiving means;
pressure regulating valve means connected between the first air
receiving means and the first and second air storage means for
permitting air above a predetermined pressure to pass
therethrough;
first and second unidirectional valve means connected to the first
air receiving means for permitting air to pass therethrough to the
first and second storage means, respectively;
first and second brake operating valve means connected for
receiving air from the first and second storage means,
respectively, for receiving air from the second air receiving means
and for supplying air from the storage means to the service brake
means;
third and fourth unidirectional valve means connected to the first
and second storage means, respectively, cooperating for selecting
air from one of the storage means and for securing the selected air
from passing to the other of the storage means;
third brake operating valve means connected for receiving the
selected air and for supplying the selected air to the parking
brake means; and
fifth unidirectional valve means in the valve portion connected for
passing air therethrough from the first air receiving means to the
third brake operating valve means bypassing the pressure regulating
valve means. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
This invention relates generally to fluid handling and more
particularly to fluid handling processes involving pressure
control.
2. DISCUSSION OF THE PRIOR ART
Presently, air brake systems for towed vehicles generally comprise
two arrangements. First, there is the type of system utilizing a
single service reservoir for providing a source of pressurized air
to all the service brake chambers and a single emergency or parking
reservoir for supplying pressurized air to all the parking brake
chambers. Second, there is the type of system utilizing more than
one service reservoir each providing a souce of air for operating
some of the service brake chambers and a single parking reservoir
for supplying pressurized air to all the parking brake
chambers.
In the first type of system, should a failure occur in that system
such as a depletion of air pressure in the service reservoir
through leakage or otherwise, there is no available air pressure
for communication with the service brake chambers thus rendering
those brakes inoperative. Also, should a failure occur in the first
system parking reservoir through leakage or otherwise, the
resultant loss of air pressure communicating with the parking brake
chamber would cause an undesirable automatic application of the
parking brakes and also prevent subsequent release of the applied
brakes.
In the second type of system, there is a slight advantage over the
first system in that, should a failure occur in the second system
such as a depletion of air pressure in one of the two service
reservoirs, there would still be some air pressure available in the
other of the two service reservoirs for communication with some of
the service brake chambers to effect partial braking. However,
should a failure occur in the single parking reservoir, the
resultant loss of air pressure communicating with the parking brake
chambers would cause the abovementioned undesirable automatic
application of the parking brakes. It would therefore be of benefit
to have a service and parking brake system offering more than
single service reservoir capability to provide at least partial
service braking in the event of failure in one of the service
systems and also offering more than single parking reservoir
capability so that, in the event of failure in one of the parking
reservoirs, there would still be air pressure communication with
the parking brake chamber to prevent the undesirable automatic
application of the parking brakes.
SUMMARY OF THE INVENTION
Accordingly, the present invention includes a service and parking
brake system preferably for towed vehicles such as trailers used in
a tractor-trailer combination having plural service reservoir
capability to provide at least partial service braking in the event
of failure in one of the service systems and also having plural
parking reservoir capability, so that in the event of failure in
one or more of the parking reservoirs, there will still be air
pressure retained in the parking brake chambers to prevent the
undesirable automatic application of the parking brakes. The
foregoing is accomplished by providing a vehicle service and
parking brake system including an air receiving portion, a valve
portion, an air storage portion and a brake portion. The air
receiving portion receives air from a supply source. The valve
portion is connected to the air receiving portion and includes a
first plurality of like valve members separated for independently
operating on the air received and for securing the air operated on
from returning to the receiving portion. The storage portion is
connected to the valve portion and includes a plurality of storage
reservoirs for independently receiving the air from the first
plurality of like valve members, respectively, and for storing the
air received. A second plurality of like valve means, corresponding
to the first valve means, are separated in the valve portion and
cooperatingly connected to the separated storage reservoirs,
respectively, for selecting air from one of the reservoirs and for
securing the selected air from passing to another of the
reservoirs. A brake portion includes service brake chambers, ones
of which are connected for receiving air from one of the storage
reservoirs, others of which are connected for receiving air from
another of the storage reservoirs and also includes parking brake
chambers connected for receiving the selected air from the storage
reservoirs.
Other advantages and novel features of this invention will become
apparent from the following detailed description of the invention
when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein like parts are marked alike:
FIG. 1 diagrammatically illustrates a prior art tandem axle vehicle
brake system utilizing one service reservoir communicating air with
the service brake chambers and one parking reservoir, communicating
air with the parking brake chambers;
FIG. 2 diagrammatically illustrates a prior art tandem axle vehicle
brake system utilizing two service reservoirs each communicating
air to some of the service brake chambers and one parking reservoir
communicating air to all the parking brake chambers;
FIG. 3 diagrammatically illustrates the novel tandem axle vehicle
brake system of this invention utilizing two reservoirs, each
communicating air with some of the service brake chambers and with
all of the parking brake chambers;
FIG. 4 diagrammatically illustrates an alternative valve portion of
the system of FIG. 3; and
FIG. 5 diagrammatically illustrates another alternative valve
portion of the system of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, it can be seem from the diagram of
FIG. 1 that a prior art brake system includes an air receiving
portion 10, a valve portion 12, a storage portion 14 and a brake
portion 16. Storage portion 14 includes a single service reservoir
18 for providing a source of pressurized air through appropriate
valve portion 12 to all the service brake chambers 20 and a single
parking reservoir 23 for providing pressurized air to all the
parking brake chambers 22. FIG. 2 illustrates another prior art
brake system including air receiving portion 10a, valve portion 13,
storage portion 15 and brake portion 16a. Storage portion 15
includes service reservoirs 24, 26, each providing a source of air
through appropriate valve portion 13 for operating some of the
service brake chambers 20a and a single parking reservoir 23a for
providing pressurized air to all the parking brake chambers
22a.
The novel brake system of this invention, as illustrated in FIG. 3
preferably for mounting on a multi or tendem axle trailer of a
tractor-trailer combination, includes an air receiving portion 10b,
a valve portion 17, a storage portion 19 and a brake portion 16b.
Storage portion 19 includes reservoirs 28, 30. Reservoir 28
provides a source of air through appropriate valve portion 17 for
operating some of the service brake chambers 20b on one of the
tandem axles 120 and also for providing pressurized air to all the
parking brake chambers 22 b. Reservoir 30 provides a source of air
through appropriate valve portion 17 for operating others of the
service brake chambers 20b on the other of the tandem axles 220 and
also for providing pressurized air to all the parking brake
chambers 22b on each axle. It can be seen from the foregoing and by
referring to the drawings that the valve portions and the storage
portions of FIGS. 1, 2 and 3 differ for controlling the air in each
system between the air receiving and brake portions.
More particularly now, FIG. 3 includes air receiving portion 10b
including means such as gladhand connectors 32, 34 for receiving
air from a supply source such as a tractor of a well known
tractor-trailer combination and designated 36 in the diagram.
Trailer gladhand connectors 32, 34 typically connect with tractor
gladhand connectors 38, 40, respectively, at the tractor-trailer
interface as is well known. First connector 32 can be connected for
receiving supply or emergency air from tractor 36 and second
connector 34 can be connected for receiving control or service air
from the tractor. Typically, the supply air is the air which passes
through storage portion 19 and valve portion 17 and is eventually
communicated to the service and parking brake chambers 20b, 22b,
respectively, whereas the control air is generally communicated to
the valve portion for operating on some of the brake operating
valves therein. However, supply air is sometimes used for operating
on the brake operating valves as well as being communicated to the
brake chambers.
Valve portion 17 is connected to air receiving portion 10b due to
conduit 42 connected to first glandhand connector 32. Conduit 44
conducts air from conduit 42 to a pressure guarding means in valve
portion 17 such as pressure protection valve 46 for permitting air
above a predetermined pressure to pass therethrough. Air passing
through valve 46 is conducted to branch conduits 48, 50 via conduit
52. A first plurality of like valve means such as first and second
unidirectional or one way check valves 54, 56 are separated for
independently receiving air from air receiving portion 10b, for
operating on the air received and for securing the air operated on
from returning to the air receiving portion. Thus, due to the use
of unidirectional valves 54, 56, once air passes therethrough, it
is precluded from returning to the air receiving portion from the
valve portion.
Storage portion 19 is connected to valve portion 17 and includes a
plurality of storage means such as first and second storage
reservoirs 28, 30 separated for independently receiving air from
valves 54, 56, respectively, and for storing the air received. This
is accomplished due to conduits 62, 64, conducting air to conduits
58, 60, respectively, which in turn conduct air to reservoirs 28,
30, respectively. Storage portion 19 may include separate storage
tanks or reservoirs 28, 30 as shown, or may include a single tank
divided to include separate reservoirs therein.
A second plurality of like valve means, such as third and fourth
unidirectional or one way check valves 66, 68, corresponding to
valves 54, 56, are separated in the valve portion and are
cooperatingly connected to storage reservoirs 28, 30, respectively,
for selecting air from either of the reservoirs, for independently
operating on the selected air, for securing the selected air from
returning to its respective storage reservoir and for securing the
selected air from passing to another of the storage reservoirs.
This is accomplished due to conduits 58, 60 conducting air from
reservoirs 28, 30, respectively. Air is further conducted from
conduits 58, 60 to conduits 62, 64, respectively, and thus to valve
66, 68, respectively.
Brake portion 16b includes service brake chambers 20b, some of
which are represented as mounted on axle 120 of a tendem axle
trailer and connected for receiving air from storage reservoir 28
and others of which are represented as mounted on axle 220 of a
tandem axle trailer and connected for receiving air from reservoir
30. This is accomplished due to conduits 70, 71, 73 connecting a
first brake operating valve 72 with some of the service brake
chambers 20b. Valve 72 is preferably a skid control type valve,
well known in the art, connected to receive air from reservoir 28
which air is eventually communicated to some of the service brake
chambers 20b via conduits 70, 71, 73 and also connected to receive
control air from second gladhand connector 34 via conduits 74, 76,
for assisting in operating the valve. Others of the service brake
chambers 20b are connected for receiving air from storage reservoir
30. This is accomplished due to conduits 78, 77, 79 connecting a
second brake operating valve 80 with the other service brake
chambers 20b. Valve 80 is preferably a skid control type valve,
similar to valve 72, well known in the art, connected for receiving
air from reservoir 30 which air is eventually communicated to the
other service brake chambers 20b via conduits 78, 77, 79 and also
connected to receive control air from second gladhand connector 34
via conduits 74, 82, for assisting in operating the valve.
The brake portion also includes parking brake chambers 22b some of
which are represented as mounted on axle 120 of a tandem axle
trailer and others of which are represented as mounted on axle 220
of a tandem axle trailer and connected for receiving the air
selected by either of valves 66, 68, from either of the storage
reservoirs 28, 30, respectively. This is accomplished due to
conduit 84 and branch conduits 86, 88 connecting third brake
operating valve 90 with all of the parking brake chambers 22d.
Valve 90 is preferably an amplifying relay valve, well known in the
art, connected to receive the selected air from either storage
reservoir 28, 30, by check valves 66, 68, respectively, which air
is eventually communicated to valve 90 via conduits 104, 106, 102.
Valve 90 may be connected to receive control air from second
gladhand connector 34 via conduits 74, 92 for assisting in
operating the valve. However, valve 90 is connected to receive
supply air from first gladhand connector 32 via conduits 42, 94 for
assisting in operating the valve.
Still further, fifth valve means such as unidirectional or one way
check valve 96, corresponding to the first, second, third and
fourth check valves 54, 56, 66, and 68, respectively, may be
connected between air receiving portion 10b and brake portion 16b
for permitting air to bypass pressure protection valve 46 and for
conducting air from gladhand connector 32 to valve 90. This is
accomplished due to conduit 98 connected to conduit 42 and conduits
100, 102, interconnecting valves 96 and 90.
Alternatively, FIG. 4 illustrates that valve portion 17 of FIG. 3
may include pressure protection valve 46a in addition to pressure
protection valve 46. Thus, air is conducted to separate storage
reservoirs 28, 30 through separate pressure protection valves 46,
46a, respectively. Air from conduit 42 passes through conduit 44 to
pressure protection valve 46, through conduit 48 to check valve 54,
thence to reservoir 28. Also, air from conduit 42 passes through
conduit 44a to pressure protection valve 46a, through conduit 50 to
check valve 56, thence to reservoir 30.
Alternatively, FIG. 5 illustrates that third and fourth check
valves 66, 68 may be replaced by two way check valve 105 in valve
portion 17 for interconnecting storage reservoirs 28, 30 and
parking brakes 22b via valve 90 and appropriate conduits. This is
accomplished due to two way check valve 105 connected for
communication with storage reservoir 28 via conduits 58, 62 and
connected for communication with valve 90 via conduit 102. Also
check valve 105 may be connected for communication with storage
reservoir 30 via conduits 60, 64 and connected for communication
with valve 90 via conduit 102. Thus, valve 105 is cooperatingly
connected to the separated storage reservoirs 28, 30 for selecting
air from one of those storage reservoirs and for securing the
selected air from passing to another of the storage reservoirs.
OPERATION
In operation, as illustrated in FIG. 3, trailer gladhand collectors
32, 34 are connected to tractor connectors 38, 40 respectively to
receive air from tractor 36. Supply air above a predetermined
minimum pressure communicates through conduits 42, 44 and opens
valve 46 to conduit 52. That air then separates through conduits
48, 50 and passes through check valves 54, 56, respectively, which
secure that air from returning to the receiving portion of the
system. Once the air is secured by the check valves, it can
communicate with storage reservoirs 28, 30 via conduits 58, 60,
respectively. Air in the storage reservoir 28 is available for
being communicated to some of the service brake chambers 20b via
skid control valve 72 and conduits 70, 71 and 73. Air in storage
reservoir 30 is available for being communicated to others of the
service brake chambers 20b via skid control valve 80 and conduits
78, 77 and 79. Also air of greater pressure in either of storage
reservoirs 28, 30 may be selected by either of check valves 66, 68,
respectively, and thence communicated to valve 90 for eventual
availability to all of the parking brake chambers 22b via conduits
84, 86, 88. Thus, for example, if pressure in reservoir 28 is
greater than pressure in reservoir 30, air will be selected from
reservoir 28 by valve 66, secured from returning to reservoir 28,
and secured from passing through valve 68 to reservoir 30 due to
the known functional characteristics of valves 66, 68. Conversely,
if pressure in reservoir 30 is greater than pressure in reservoir
28, air will be selected from reservoir 30 by valve 68, secured
from returning to reservoir 30 and secured from passing through
valve 66 to reservoir 28, as stated before, due to the known
functional characteristics of valves 66, 68.
As previously discussed, FIG. 5 illustrates that third and fourth
check valves 66, 68 may be alternatively replaced by a single
two-way check valve 105. The function of this two-way check valve
is similar to the two one-way check valves 66, 68 but does not
represent the preferred embodiment. For example, if pressure in
reservoir 28 is greater than pressure in reservoir 30, air will be
selected from reservoir 28 by valve 105 and may be communicated to
valve 90 via conduit 102. The selected air is not secured from
returning to storage reservoir 28 as when one-way check valve 66 is
used but is secured from passing to storage reservoir 30 due to the
well known functional characteristics of valve 105. Conversely, if
pressure in reservoir 30 is greater than pressure in reservoir 28,
air will be selected from reservoir 30 by valve 105 and may be
communicated to valve 90 via conduit 102. The selected air is not
secured from returning to storage reservoir 30 as when one-way
check valve 68 is used but is secured from passing to storage
reservoir 28 due to the known functional characteristics of valve
105. Thus, it can be seen that for example, in the event of loss of
air pressure in the service system including storage reservoir 28
and some of the service brake chambers, at least partial braking
would be available to others of the service brake chambers through
that part of the service system including storage reservoir 30.
Further, in the event of loss of air pressure in storage reservoir
28 there would also still be some air pressure communication with
the parking brake chambers due to their communication with storage
reservoir 30 to prevent automatic application of the parking
brakes. Or, for example, in the event of loss of air pressure in
the service system including storage reservoir 30 and some of the
service brake chambers, at least partial braking would be available
to others of the service brake chambers through that part of the
service system including storage reservoir 28. Further, in the
event of loss of air pressure in the storage reservoir 30 there
would also still be some air pressure communication with the
parking brake chambers due to their communication with storage
reservoir 28 to prevent automatic application of the parking
brakes.
The advantage of adding check valve 96 is that it interconnects
supply air received at gladhand connector 32 with valve 90 by
bypassing pressure protection valve 46 and either check valves 54,
56, 66 and 68 as shown in FIG. 3, or check valves 54, 56 and 105 as
shown in FIG. 5. For example, in the event of a failure which
depletes air pressure in any one or both of the storage reservoirs,
for example, reservoir 28, pressure protection valve 46 will
function to limit the reduction of pressure in supply line conduit
42 to a fixed value which may be arbitrarily established at 47 psi.
Also if the predetermined minimum opening pressure of valve 46 is
50 psi, then supply line pressure will be insufficient to pass air
through valve 46, and, even if air did pass through valve 46, it
would go to atmosphere through the failed portion of the system
since the air would seek the path of least resistance, or lower
pressure. Eventually, cycling of skid control valve 80 can reduce
and deplete pressure in reservoir 30. Thus, it would be possible
under these conditions for the pressure in both reservoirs 28 and
30 to approach 0 psi despite the existence of usable pressure in
supply line conduit 47 at 47 psi. The addition of check valve 96
will permit the 47 psi supply line pressure to have access to
amplifying relay valve 90 thus making needed pressure available to
release the parking brakes thus providing some braking capability
to the vehicle.
The addition of pressure protection valve 46a, FIG. 4, is
advantageous since pressure protection valves 46, 46a, although
theoretically having the same opening pressure, e.g. 50 psi, do not
open at exactly the same pressure. More realistically, one of the
valves may open at a lower pressure, for example 49.5 psi, and the
other may open at a higher pressure, for example 49.6 psi.
Therefore, adding valve 46a may increase the reliability of the
system against failure by 50 percent. For example, in the event
failure due to loss of air pressure in that portion of the system
including reservoir 28 with the portion of the system including
reservoir 30 remaining intact and in the event that valve 46 has
the higher opening pressure requirement, air from supply line 42
will pass through valve 46a having the lower opening pressure
requirement since the air will seek the path of least resistance.
Thus, air from supply line 42 will replenish that portion of the
system including the intact reservoir 30. Of course, if under the
above circumstances, valve 46a has the higher opening pressure
requirement, air from supply line 42 will pass through valve 46 and
eventually to atmosphere through the failed portion of the system.
However, supply air access to the separate reservoirs through
pressure protection valves 46, 46a, may increase the reliability of
the system.
Even in the two pressure protection valve system of FIG. 4, it
would be advantageous to maintain check valve 96 interconnecting
supply air conduit 42 and valve 90. For example, in the event of a
failure which depletes air pressure in any one or both of the
storage reservoirs, for example reservoir 28, pressure protection
valves 46, 46a will function to limit the reduction of pressure in
supply conduit 42 to a fixed value which may be arbitrarily
established at 47 psi. Also, if the predetermined minimum opening
pressures of valves 46, 46a are greater than 47 psi then supply
line pressure will be sufficient to pass air through the pressure
protection valves, and even if it did pass through, for example
valve 46a due to that valve having the lower opening pressure
requirement, and did pass to the intact portion of the system
including reservoir 30, eventually cycling of the skid control
valve 80 could reduce and deplete the pressure in reservoir 30.
Thus it would be possible under these conditions for the pressure
in both reservoirs 28 and 30 to approach 0 psi despite the
existence of usable pressure in supply line conduit 42 and 47 psi.
The addition of check valve 96 will permit the 47 psi pressure to
have access to the amplifying relay valve 90 bypassing pressure
protection valves 46, 46a making needed pressure available to
release the parking brakes for providing some braking capability of
the vehicle.
The foregoing has described a service and parking brake system
ofering more than single service reservoir capability to provide at
least partial service braking in the event of failure in one of the
service systems and also ofering more than single parking reservoir
capability so that, in the event of failure in one of the parking
reservoirs, there would still be air pressure communication with
the parking brakes to prevent the undesirable automatic application
of the parking brakes.
Obviously, other modifications and variations of the present
invention are possible in the light of the above teachings. It is
therefore understood that within the scope of the appended claims
the invention may be practiced otherwise than as specifically
described.
* * * * *