Patent US6610009B2 successfully refreshed from Google Patents.
Patent US5320191A successfully refreshed from Google Patents.
US5320191A
Expired / Lapsed
US
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Steering circuit system for a moving vehicle
Assignee: Komatsu Ltd
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Filing: 1993-01-28
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Granted: 1994-06-14
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Expires: 2013-01-28
Abstract
Abstract A steering circuit system for a moving vehicle in which automatic steering operation as well as manual steering operation can be achieved. Pressurized oil discharged from a hydraulic pump (1) is fed to a steering line (3) and to an auxiliary steering line (10). The pressurized oil of the steering line (3) is fed to an expanding chamber (9a, 90a) and to a contracting chamber (9b, 90b) of a pair of steering cylinders (9, 90) by manual operation steering valve (5). The auxiliary steering line (10) is connected to a third line (12) through a switching valve (11). The third line (12) is connected to a fourth line and to a fifth line (14, 15) through an automatic operation steering valve (13). The fourth line (14) is connected to contracting chamber (9b) and to expanding chamber (90a) of the left and right steering cylinders (9, 90). The fifth line (15) is connected to contracting chamber (90b ) and expanding chamber (9a) of the left and right steering cylinders (9, 90). First and second pilot operation check valves (16, 17) are provided in the fourth and the fifth lines (14, 15), respectively. The first pilot operation check valve is opened in response to pressure in the fifth line (15), and the second pilot operation valve is opened in response to pressure in the fourth line (14).
Inventors
- 👤 Tsugio Sudo
- 👤 Takao Nagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:44
CPC Classifications
B; B62; B62D; B62D1/00; B62D1/24; B62D1/26; B62D5/00; B62D5/06; B62D5/09
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
211 words
A steering circuit system for a moving vehicle, comprising: a first hydraulic line; a second hydraulic line; a hydraulic pump having a discharge line; a first steering cylinder having a first expanding chamber and a first contracting chamber; a manual operation steering valve connected to the discharge line of the hydraulic pump and having a first position connecting the discharge line with the first contracting chamber by way of the first line, and a second position connecting the discharge line with the first expanding chamber by way of the second line; a third hydraulic line; a switching valve connecting discharge line to the third line; a fourth line having a first pilot operation check valve therein, and a fifth line having a second pilot operation check valve therein, wherein the first pilot operation check valve is constructed to open in response to oil pressure in the fifth line and the second pilot operation check valve is constructed to open in response to pressure in the fourth line; an automatic operation steering valve having a first position connecting the third line to the first contracting chamber by way of the fourth line, and having a second position connecting the third line to the first expanding chamber by way of the fifth line.
Claim 2
Dependent Claim
211 words
A steering circuit system for a moving vehicle, comprising: a first hydraulic line; a second hydraulic line; a hydraulic pump having a discharge line; a first steering cylinder having a first expanding chamber and a first contracting chamber; a manual operation steering valve connected to the discharge line of the hydraulic pump and having a first position connecting the discharge line with the first contracting chamber by way of the first line, and a second position connecting the discharge line with the first expanding chamber by way of the second line; a third hydraulic line; a switching valve connecting discharge line to the third line; a fourth line having a first pilot operation check valve therein, and a fifth line having a second pilot operation check valve therein, wherein the first pilot operation check valve is constructed to open in response to oil pressure in the fifth line and the second pilot operation check valve is constructed to open in response to pressure in the fourth line; an automatic operation steering valve having a first position connecting the third line to the first contracting chamber by way of the fourth line, and having a second position connecting the third line to the first expanding chamber by way of the fifth line.
Claim 3
Dependent Claim
83 words
A steering circuit system according to claim 1, further comprising a second steering cylinder having a second expanding chamber and a second contracting chamber, wherein said automatic operation steering valve connects said third line to the second contracting chamber by way of said fifth line when said automatic operation steering valve is in said second position, and connects said third line to the second expanding chamber by way of said fourth line when said automatic operation steering valve is in said first position.
Claim 4
Dependent Claim
41 words
A steering circuit system according to claim 1, further comprising a first pilot line connecting said fifth line with said first pilot operation check valve, and a second pilot line connecting said fourth line and said second pilot operation check valve.
Claim 5
Dependent Claim
66 words
A steering circuit system according to claim 2, wherein when said manual steering valve is in said first position said discharge line is connected to said expanding chamber of said second cylinder by way of said first line, and wherein when said manual steering valve is in said second position said discharge line is connected to the second contracting chamber by way of said second line.
Claim 6
Dependent Claim
22 words
A steering circuit system according to claim 3, wherein each of said first and second pilot operation check valves comprises a throttle.
Claim 7
Dependent Claim
36 words
A steering circuit system according to claim 1, wherein said automatic operation steering control valve has a third, neutral position in which said third line is not connected to either said fourth or said fifth lines.
Claim 8
Dependent Claim
23 words
A steering control circuit according to claim 1, further comprising first and second solenoids for actuating said switching and automatic operation steering valves.
Claim 9
Dependent Claim
24 words
A steering control circuit according to claim 1, further comprising a drain line for draining oil from said first, second, fourth and fifth lines.
Claim 10
Dependent Claim
57 words
A steering control circuit according to claim 8, further comprising a fourth line drain line having a check valve therein and connected to said drain line for draining oil from the fourth line, and a fifth line drain line having a check valve therein and connected to said drain line for draining oil from said fifth line.
Claim 11
Dependent Claim
28 words
A steering control unit according to claim 1, further comprising a demand valve disposed in the discharge line upstream of the switching valve and manual operation steering valve.
Claim 12
Dependent Claim
17 words
A steering control unit according to claim 1, further comprising an accumulator disposed in the third line.
Claim 13
Dependent Claim
31 words
A steering control unit according to claim 3, further comprising a first orifice check disposed in the first pilot line, and a second orifice check disposed in the second pilot line.
Claim 14
Dependent Claim
26 words
A steering control unit according to claim 12, wherein the first orifice check comprises a first throttle, and the second orifice check comprises a second throttle.
References Cited (Backward Citations)
US4219093A
Cited
JPS6170618A
Cited
WO1986005455A1
Cited
DE3619331A1
Cited
JPH03184137A
Cited
JPH058742A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-13 | 1997-12-13 | 1998-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-13 | 2001-12-13 | 2002-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-13 | 2005-12-13 | 2006-06-14 | $7700.00 | Window Closed / Lapsed |