Pumps – Motor driven – Electric or magnetic motor
Reexamination Certificate
2001-06-28
2003-03-11
Walberg, Teresa (Department: 3742)
Pumps
Motor driven
Electric or magnetic motor
C415S152100
Reexamination Certificate
active
06530758
ABSTRACT:
BACKGROUND
Vehicle windshield washer systems include a washer fluid reservoir mounted in the engine compartment. A motor-driven pump draws fluid from the reservoir and pumps the fluid under pressure through conduits connected to the pump housing to spray nozzles in the vicinity of the windshield to dispense the fluid over the windshield.
The washer fluid pump, when activated, rotates an impeller in one of two directions to pump fluid through flow channels in the pump housing to different spray nozzles, one of which may also be located on the rear vehicle window.
Fluid reservoir level sensors are mounted on the reservoir to detect a predetermined low fluid level. A sensor output is used to activate an alarm, such as a light, within the vehicle to signal the driver to replenish the washer fluid.
One typical sensor assembly has a tubular column connected to the side of the fluid reservoir and is fluidically coupled to the reservoir at a bottom end. The fluid level in the column, which corresponds to the level of fluid in the reservoir, is detected by a float disposed within the column. Circuitry connected to the float generates the alarm signal at a predetermined float level.
This type of sensor configuration can be complicated due to the many parts and space consumed by the tubular column. This imposes severe design restrictions on the entire windshield washer assembly due to limited space in the engine compartment. The tubular housing also restricts design freedom for the shape and mounting position of the fluid reservoir.
Another sensor arrangement uses two electrodes having free ends spaced apart in the reservoir. The washer fluid shorts the electrodes when the fluid level is above the electrodes and the electrode ends are completely immersed in the washer fluid. When the electrodes are clear of fluid, an open circuit exists between the electrodes which can be detected by circuitry coupled to the electrodes to generate the low fluid level signal.
Such a sensor design is simpler in construction than the separate tubular column sensor, but is still separately mounted in the reservoir from the washer fluid pump.
The windshield washer fluid pump is typically mounted in a housing adjacent to the fluid reservoir and coupled to a discharge outlet on the reservoir. Typically, a multiple-part housing is used to couple the reservoir discharge outlet to a fluid conduit coupled to the pump housing for the discharge of washer fluid through the pump housing and the attached conduit to the remote spray nozzle.
The separate fluid carrying parts of the pump housing require a seal for fluid tight operation. Typically, the seal is a separate, thin, small gasket mounted between two pump housing parts. The gasket is typically held in position between the two pump housing parts by a snap-fit feature wherein the seal fits into a groove on the outside or between the pump housing parts.
However, due to the thin, flimsy nature of the seal, handling and assembly of the seal onto a seal carrier or in the pump housing parts have proven difficult, thereby frequently resulting in improper seal mounting and lengthy assembly time.
In certain windshield washer configurations, the washer pump is a bidirectional pump having two flow outlets formed in the pump housing. Depending upon a direction of revolution of the pump impeller, only the outlet in the direction of revolution is open; while the other outlet is closed. This alternating flow path switching is controlled by a valve system established by two silicone or rubber membranes, one facing up and the other facing down in valve grooves between two parts of the pump housing. The valves are formed as check valves and alternately open and close flow paths to the respective pump housing outlets in response to the direction of fluid flow created by rotation of the pump impeller.
In addition, the seal carrier also carries a motor shaft seal to seal the connection of the pump motor to the impeller. In prior washer fluid pump assemblies, each of these multiple sealing functions required a separate seal element which was separately mounted onto the carrier. This resulted in a relatively expensive, difficult to assemble pump housing.
Thus, it would be desirable to provide a windshield wiper fluid system which has improved level sensing and sealing characteristics as compared to previously devised windshield washer fluid pump systems.
SUMMARY
A fluid control apparatus is disclosed for use in a vehicle windshield washer fluid pump having a pump housing formed of at least first and second joinable housing parts, the first housing part including a fluid inlet and at least one of the first and second housing parts including a first fluid outlet.
The fluid control apparatus includes a body mounted between the first and second housing parts. A resilient seal member is mounted on the body for sealing the first and second housing parts. At least one check valve is carried on the body and is movable between a first position blocking fluid flow between the fluid inlet and the first fluid outlet, and a second position opening fluid flow between the inlet and the first fluid outlet. The seal member and the at least one check valve are preferably molded onto the body.
A first aperture is formed in the body, with the at least one check valve disposed over the first aperture.
A pump shaft aperture is also formed in the body. A shaft seal formed of a resilient material is molded over the shaft aperture in the body as an integral part of the body.
In one aspect of the invention, two check valves are molded over two separate apertures formed in the body. Two fluid outlets are also preferably formed in the first and second housing parts, respectively, in another aspect of the invention. Fluid pressure paths are formed in at least one of the first and second housing parts in fluid communication between the inlet and the two check valves for directing pressurized fluid from the inlet through one of the fluid pressure flow paths to one of the first and second check valves to move one check valve to the first position and to bias the other check valve to the other closed position to selectively establish a fluid flow path between the inlet and a selected one of the first and second outlets.
The body preferably includes a peripheral edge, a first fluid flow aperture and another aperture receiving a pump motor shaft. The seal member is molded onto the peripheral edge of the body. The shaft seal is molded over the aperture to define a pump motor shaft seal.
Preferably, the first and second housing parts of the pump housing are snap connected together. A top cover surrounds a pump motor and is joined to the second housing part. Preferably, the top cover is snap connected to the second housing part.
Another aspect of the invention is a fluid control apparatus for use in a vehicle windshield washer apparatus having a washer fluid containing reservoir with a discharge outlet. The fluid control apparatus includes a pump including an electric motor having a rotatable output shaft and an impeller connected to the output shaft.
A housing containing the pump is formed of at least first and second joinable housing parts, the first housing part including a fluid inlet, at least one of the first and second housing parts including a fluid outlet. The first housing part includes a first fluid inlet adapted to be connected to the discharge outlet of a washer fluid reservoir, and a first outlet. The second housing part includes a second fluid outlet, a body mounted between the first and second housing part, and a resilient seal member mounted on the body for sealing the first and second housing parts. First and second check valves are carried on the body, each movable between a first position blocking fluid flow between the inlet and one of the first and second outlets, respectively, and a second open position opening fluid flow between the inlet and the other of the first and second fluid outlets. The seal member and first and second check valves are molded onto the body.
Another aspect of the invention is
Benner Mark M.
Kuebler Karl-Heinz
Ritter Andreas
Fastovsky Leonid M
Lewis J. Gordon
Valeo Electrical Systems, Inc.
Walberg Teresa
LandOfFree
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