Note: Descriptions are shown in the official language in which they were submitted.
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48907-4
BRAKE BLEEDING APPARATUS
FIELD OF THE INVENTION
This invention relates generally to hydraulic
systems and more particularly to a hydraulic fluid
bleeding apparatus for the removal of air or other
contaminants from automotive brake systems, commonly
referred to as bleeding.
BACKGROUND OF THE INVENTION
Bleeding automotive brake systems of air and other
contaminants is an important process in vehicle
maintenance. Most modern brake systems rely on hydraulic
fluid lines and cylinders that are controlled by
operation of the brake pedal. When air is present in the
system, the air compresses as the brake pedal is pressed
which lowers the hydraulic pressure and the overall
braking power of the system and results in a "spongy"
feel to the brakes.
The conventional method for correcting the above
problem involves the co-operation of two people to bleed
the brakes. One person inside the vehicle depresses the
brake pedal while the other person opens the bleed screw
port at a particular wheel, generally by loosening the
screw-threaded bleed nipple to drain contaminated fluid.
The bleed screw port must then be closed and the brake
pedal released. This process is repeated until all air
and other contaminants are purged from the system. The
same procedure must be performed for each wheel.
Obviously, this procedure is costly to a business as two
workers are required to bleed one set of brakes. For a
home mechanic, the second person is often not available
to assist.
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To address these problems, various brake bleeding
systems have been developed. Applicant is aware of the
following patents covering apparatus and methods for
bleeding brakes that can be operated by a single person:
5,273,141 Veret et al
2,645,314 Lackinger
2,505,213 Schnell
2,295,539 Beach
5,653,316 Kane
5,497,864 Oien
5,410,88l Ellis
4,842,107 Buchanan et al
4,741,417 Caramanna
4,655,328 Tideberg
4,497,176 Rubin et al
4,418,803 Chichester
4,4l5,071 Butler et al
4,038,823 Mostert
3,756,367 Mitchell et al
3,548,978 Dyke
3,425,7S0 Deane
3,154,087 Beaver
2,644,548 Schiemann
2,524,544 Seawell
2,872,951 Wilkerson
2,209,784 Maack et al
1,82S,013 Patton
1,617,020 Merwin
Generally, these patents disclose systems that rely
on an external pressure or vacuum source to force
hydraulic fluid through the lines of the system and bleed
screw ports so that an additional individual is not
required to pump the brake pedal. This equipment tends
to be expensive and bulky, and it is not always possible
to connect the equipment to a particular vehicles
braking system due to the large number of variations
possible in the design of the basic braking system.
SUMMARY OF THE INVENTION
Accordingly, there is a need for a brake bleeding
apparatus that can be operated by one person and that is
simple to operate and inexpensive. Furthermore, it is
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desirable that the apparatus be usable with virtually a11
vehicle brake systems.
To address the foregoing needs, applicant has
developed a brake bleeding apparatus that relies on
remote controlled activation of the vehicle brake pedal
to bleed the brakes. Accordingly, the present invention
provides apparatus for bleeding the brakes of a vehicle
using a hydraulic braking system activated by a brake
pedal comprising:
a brake pedal manipulating unit installable in the
vehicle to engage with the brake pedal; and
a remote control switch for activating the unit to
press and release the brake pedal as desired by the user
to provide hydraulic pressure to bleed the brakes.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of the present invention are illustrated,
merely by way of example, in the accompanying drawings in
which:
Figure 1 is a view of a preferred embodiment of the
bleeding apparatus of the present invention;
Figure 2 is a schematic view of the components of
the bleeding apparatus of Figure 1;
Figure 3 is a detail view showing the manner in
which the bleeding apparatus engages with the brake pedal
of a vehicle;
Figure 4 is a detail view of a brake fluid discharge
container for use with the bleeding apparatus of the
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present invention attached to the bleed screw port at a
vehicle wheel; and
Figure 5 is a detail view of a brake fluid supply
container for use with the bleeding apparatus of the
present invention in order to supply make-up brake fluid
to the system at the master cylinder reservoir.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Figure 1, there is shown the brake
pedal manipulation unit 4 of the brake bleeding apparatus
of the present invention installed within a vehicle in a
typical orientation. Pedal manipulation unit 4 is
operated by a remote control switch 6 (Figure 2) retained
by a worker positioned outside the vehicle at a wheel for
ready access to the brake fluid bleed screw port. Pedal
manipulation unit 4 is operated to automatically press
brake pedal 8 to supply the pressure necessary to purge
the brake system at the wheel being serviced.
Pedal manipulation unit 4 comprises a main housing
10 that houses the control means for the unit which
responds to the control signals of the remote control
switch. A cylinder 12 having a elongatable piston arm 14
extends from main housing 10. As best shown in Figure 3,
piston arm 14 has a free distal end 16 to which is
mounted a brake pedal engaging member in the form of hook
member 20 which is releasably attachable to brake pedal
8. Curved top end 24 of hook member 20 is adapted to fit
over brake pedal 8 to secure the hook member 20 in place.
It is desirable for hook member 20 to be provided
with an adjustable stop member 25 to limit movement of
the brake pedal. By way of example, Figure 3 shows an
adjustable stop member 25 comprising a threaded bolt 26
engaged in a correspondingly threaded sleeve 28 in hook
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member 20. Rotation of bolt 26 in sleeve acts to adjust
the length 30 of bolt 26 protruding below the hook member
such that engagement of the bolt with the floorboard 32
of the vehicle stops further movement of piston arm 14.
Preferably, hook member 20 is mounted to piston arm
end 16 via a pivotable joint 22 to accommodate arcuate
movement of brake pedal 8 and installation of the brake
pedal manipulation unit 4 in different vehicles.
Referring again to Figure 1, main housing 10 and
cylinder 12 co-operate to define an elongate brake pedal
manipulation unit 4 that is adapted be installed between
brake pedal 8 and the steering wheel 34 of the vehicle.
The overall length of unit 4 and the adjustable length of
piston arm 14 are selected such that the unit is
installable in virtually a11 common cars and trucks. The
universal use of a brake pedal substantially aligned
below the steering wheel of a vehicle means that the
apparatus of the present invention can be used in
virtually any vehicle equipped with a hydraulic braking
system. Preferably, the end of main housing 4 opposite
cylinder 12 is formed with a hook member 35 to releasably
connect to steering wheel 34 by hooking over the lower
portion of the steering wheel.
Figure 2 is a schematic view of the components of a
preferred embodiment of the brake bleeding apparatus of
the present invention. In Figure 2, the main housing is
represented by box 10 which encloses the components
normally located in the main housing. In this preferred
embodiment, the brake manipulation unit is connectable to
an electric power supply 42 via line 43 and a source of
air pressure 44 via air hose 45. Both power supply 42
and air pressure source 44 are readily available in a
garage. It will be readily apparent that an alternative
power supply such as a battery can be used and/or an
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alternative pressure source such as a hydraulic pressure
source.
In the embodiment illustrated in Figure 2, piston
arm 14 is an air piston that communicates through line 45
with air pressure source 44 via regulator 46 and air
control valve 48. Regulator 46 is manually adjustable by
knob 49 extending externally of main housing 10 to set
the maximum air pressure deliverable to piston arm 14.
Control valve 48 operates to selectively communicate air
pressure source 44 with the piston arm 14 to extend the
piston arm. Control valve 48 is actuated in response to
a control signal from remote control switch 6.
In the preferred embodiment of Figure 2, remote
control switch 6 is mounted in a transmitter that is
carried by the user. Depressing switch 6 generates a
control signal 55 that is received by receiver 50 in main
housing 10. Receiver 50 in turn activates solenoid 52 to
operate air control valve 48. Receiver 50 and solenoid
52 receive power from power supply 42. The transmitter
and receiver can be simple radio units such as are used
to open garage doors. It is also possible for switch 6
to be directly connected to solenoid 52 by wires,
however, this arrangement would limit the ability of the
user to move freely about the vehicle as the user must be
careful to manage the path of the connecting wire.
It is intended that piston arm 14 is a single acting
piston in the preferred embodiment. Pressing of control
switch 6 by the user will extend piston arm 14 to depress
brake pedal 8. When switch 6 is released, piston arm 14
is retracted into cylinder 12 by the normal movement of
brake pedal 8 to its default rest position. It is also
possible to employ a double acting piston in which switch
6 has two positions: one to extend the piston and the
other to retract the piston. In a still further
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variation, switch 6 and solenoid 52 can be designed such
that piston arm 14 and hence brake pedal 8 depressed
until switch 6 is activated a second time. This
alternative switch arrangement will avoid the need for
the user to keep switch 6 (and hence brake pedal 8)
depressed so that both hands will be free to tighten the
bleed screw port being worked on.
Figures 4 and 5 illustrate auxiliary equipment that
is useful with the brake bleeding apparatus of the
present invention.
Figure 4 shows a brake fluid discharge container 60
that is connectable to the bleed screw port 62 of a
vehicle brake at the wheel hub 63 to collect purged brake
fluid. Brake fluid discharge container 60 includes a
fluid receptacle 61 and a flexible attachment 66
removably and sealingly installable over nipple 64
installed in bleed screw port 62. Attachment 66 is
preferably a rubber hood and is dimensioned for a sealing
fit over nipple 64 while still permitting access to nut
65 for opening and closing bleed screw port 62. A tube
section 67 communicates flexible attachment 66 with
receptacle 61. A one-way valve 68 is located in tube
section 68 and acts to permit flow of brake fluid out of
the bleed screw port as indicated by arrow 69 but
prevents purged fluid or air from moving in the opposite
direction.
When bleeding the brakes of a vehicle, a user is
removing fluid from the system along with air and other
contaminants. It is important to keep the brake fluid
level topped up at the master cylinder reservoir of the
brake system so that air is not introduced inadvertently
at the reservoir by running the reservoir dry. Figure 5
illustrates a brake fluid supply device 72 for supplying
fresh brake fluid to the conventional reservoir 73 at the
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master cylinder 74 of the braking system. Brake fluid
supply device 72 comprises a container 75 to store fresh
brake fluid 76 that sits atop the existing reservoir 73.
Container 75 includes a filling port 77 and cap 77a and
an outlet port 78 in the base 79 to deliver fresh brake
fluid by gravity to master cylinder reservoir 73 of the
braking system. An automatic shut-off valve 80 is
provided for closing outlet port 78 when the reservoir
fluid reaches a pre-determined level indicated by line
81. Automatic shut-off valve 80 includes a float ball 82
enclosed in a cage 83. Float ball 82 floats on the
surface of the reservoir fluid to rise and close the port
when the reservoir fluid reaches level 80 and to fall and
open the port when the reservoir fluid drops below level
80. In addition, a manual shut-off valve 85 is provided
to seal outlet port 78 when removing the brake fluid
supply device 72 from the reservoir of the braking
system. Valve 85 is a threaded post that is rotatable to
move downwardly block and seal outlet port 78.
Although the present invention has been described in
some detail by way of example for purposes of clarity and
understanding, it will be apparent that certain changes
and modifications may be practised within the scope of
the appended claims.
