Claims
- 1. A magneto-rheological fluid device, comprising:a housing defining a cavity; a piston slidably disposed in the cavity, the piston dividing the cavity into first and second portions; a passage defined on an exterior surface of the piston fluidly coupling the first and second portions of the cavity; a magneto-rheological fluid disposed in the cavity such that motion of the piston is damped by flow of the magneto-rheological fluid through the passage; and a magnet disposed to produce a magnetic field within the cavity substantially parallel to the motion of the piston at the exterior surface of the piston.
- 2. The magneto-rheological fluid device according to claim 1, wherein the piston is formed of a non-magnetic material.
- 3. The magneto-rheological fluid device according to claim 2, wherein the housing is formed of a non-magnetic material.
- 4. The magneto-rheological fluid device according to claim 2, wherein amount of damping varies according to a magnitude of the magnetic field.
- 5. The magneto-rheological fluid device according to claim 1, wherein the housing is formed of a ferrous material.
- 6. The magneto-rheological fluid device according to claim 1, further comprising a second piston slidably disposed in the cavity, the second piston further dividing the cavity into a third portion.
- 7. The magneto-rheological fluid device according to claim 1, wherein amount of damping varies according to a magnitude of the magnetic field.
- 8. The magneto-rheological fluid device according to claim 1, wherein the magnet includes an electromagnet.
- 9. The magneto-rheological fluid device according to claim 1, wherein the magnet is disposed around the housing.
- 10. The magneto-rheological fluid device according to claim 1, wherein the magnet is disposed around the piston in a piston body.
- 11. The magneto-rheological fluid device according to claim 1, wherein a sleeve is disposed around the piston in a piston body.
- 12. The magneto-rheological fluid device according to claim 1, wherein the passage includes an axial portion and a transverse portion formed on the exterior surface of the piston.
- 13. The magneto-rheological fluid device according to claim 12, wherein the transverse portion is formed along a circumference of the piston.
- 14. The magneto-rheological fluid device according to claim 1, wherein the magneto-rheological fluid forms chains parallel to the passage in response to the magnetic field.
- 15. The magneto-rheological fluid device according to claim 1, further comprising an end cap.
- 16. The magneto-rheological fluid device according to claim 15, wherein the end cap includes a ferrous material to direct the magnetic field.
- 17. The magneto-rheological fluid device according to claim 1, further comprising a cover disposed around the magnet.
- 18. The magneto-rheological fluid device according to claim 17, wherein the cover is formed of a ferrous material to provide a return path for the magnetic field.
Parent Case Info
The present invention claims the benefit of U.S. Provisional Patent Application No. 60/109,187, filed Nov. 20, 1998, which is hereby incorporated by reference.. The present application also incorporates by reference U.S. Patent Application Ser. No. 08/901,896, filed Jul. 29, 1997, now U.S. Patent No. 6,019,201.
US Referenced Citations (82)
Foreign Referenced Citations (18)
Number |
Date |
Country |
1 084 528 |
Jun 1960 |
DE |
3631107 |
Mar 1988 |
DE |
3800678 |
Jul 1989 |
DE |
0 297 608 |
Jan 1989 |
EP |
1.094.516 |
May 1955 |
FR |
756107 |
Aug 1956 |
GB |
1 282 568 |
Jul 1972 |
GB |
2 186 947 |
Aug 1987 |
GB |
58-113644 |
Jul 1983 |
JP |
58-221034 |
Dec 1983 |
JP |
63-001833 |
Jan 1988 |
JP |
63-180742 |
Jul 1988 |
JP |
63-210432 |
Sep 1988 |
JP |
63-231031 |
Sep 1988 |
JP |
5-162524 |
Jun 1993 |
JP |
1248875 |
Aug 1986 |
SU |
1249229 |
Aug 1986 |
SU |
WO 9804846 |
Feb 1998 |
WO |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/109187 |
Nov 1998 |
US |