Pipes and tubular conduits – With pressure compensators – Variable capacity chambers
Reexamination Certificate
2000-09-22
2001-08-07
Hook, James (Department: 3752)
Pipes and tubular conduits
With pressure compensators
Variable capacity chambers
C138S040000, C138S044000, C181S256000
Reexamination Certificate
active
06269841
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a new energy attenuation apparatus for a system conveying a liquid under pressure and to a method of attenuating energy in such a system. The invention is particularly suitable for placement in a system conveying liquid under pressure for the attenuation of pressure pulsations in the liquid, especially in the hydraulic system of the power steering unit of a vehicle. The invention would also be suitable for other hydraulic fluids.
2. Prior Art Statement
In hydraulic systems where the operating liquid is circulated by a pump, the pulsations of pressure that are generated by the pump are transmitted through the conduits and result in noise and/or vibration being produced by the hydraulic liquid. In the case of power steering fluid in vehicles, such noise and/or vibration is caused, for example, when vehicles are being parked or unparked at idle or very low speeds of movement thereof, such as by barely moving into and out of a parking space or the like while the wheels of the vehicle are being turned by the power steering mechanism thereof. In particular, substantial noise and/or vibration (shudder) can be produced in such a situation when the power steering fluid passes through the power steering mechanism from the fluid pump to the effective steering structure. Further background in this area can be obtained from U.S. Pat. No. 3,323,305, Klees, whereby this U.S. Patent is being incorporated into this disclosure by this reference thereto.
Devices are known for suppressing noise in exhaust gas mufflers. For example, U.S. Pat. No. 4,501,341, Jones, provides two side branch resonators, while U.S. Pat. No. 4,371,053, Jones, provides for an apertured tube in a gas muffler housing. Systems are also known for controlling the resonation of pressure waves in fuel injection systems. For example, U.S. Pat. No. 5,168,855, Stone, passes fluid through check valves that are provided with a flow restriction either directly therein or in a bypass line. U.S. Pat. No. 5,509,391, DeGroot, provides a spool valve assembly for controlling flow between inlet and outlet ports. Henderson et al, U.S. Pat. No. 4,671,380, discloses a long and narrow tubular casing having a perforated tube extending therethrough. “Acoustics of Ducts and Mufflers”, by M. L. Munjal, provides a resonator for conveying gas in the form of an apertured tube disposed in a tubular cavity. Finally, U.S. Pat. No. 5,539,164, van Ruiten, discloses a power steering attenuation hose construction that utilizes wound or coiled metal tuning cables.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved apparatus and method for attenuating energy in a system that conveys liquid under pressure.
This object is realized pursuant to the energy attenuation apparatus of the present invention by providing a tubular means having an inlet opening for receiving liquid from the system, and an outlet opening for returning the liquid to the system, wherein an inlet conduit extends concentrically into the tubular means through the inlet opening thereof, wherein an annular space is formed between the inlet conduit and the tubular means, and wherein in a portion of the inlet conduit disposed in the tubular means the inlet conduit is provided with at least one aperture for introducing liquid therefrom into the annular space.
Accordingly, it is an object of this invention to provide a novel energy attenuation apparatus having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide a new method of attenuating energy in a system conveying liquid under pressure, the method of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Other objects, uses and advantages of this invention are apparent from a reading of the specification in conjunction with the accompanying schematic drawings, which form a part thereof and wherein:
REFERENCES:
patent: 3323305 (1967-06-01), Klees
patent: 4371053 (1983-02-01), Jones
patent: 4501341 (1985-02-01), Jones
patent: 4611633 (1986-09-01), Buchholz et al.
patent: 4671380 (1987-06-01), Henderson et al.
patent: 5168855 (1992-12-01), Stone
patent: 5172729 (1992-12-01), Vantellini
patent: 5201343 (1993-04-01), Zimmermann et al.
patent: 5495711 (1996-03-01), Kalkman et al.
patent: 5509391 (1996-04-01), DeGroot
patent: 5539164 (1996-07-01), Van Ruiten
patent: 5728981 (1998-03-01), Van Ruiten
patent: 5941283 (1999-08-01), Forte
patent: 6073656 (2000-06-01), Chen et al.
patent: 6123108 (2000-09-01), Chen et al.
patent: 6125890 (2000-10-01), Cooper et al.
“Acoustics of Ducts and Mufflers” by M.L. Munjal, pp. 71-72 Copyright 1987 by John Wiley & Sons, Inc.
Chen Yungrwei
Cooper Jack R.
Dayco Products LLC
Hook James
Tassone Joseph V.
LandOfFree
Energy attenuation apparatus for a system conveying liquid... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Energy attenuation apparatus for a system conveying liquid..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Energy attenuation apparatus for a system conveying liquid... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2551209