# US 7,610,988 B2 · Hydraulic steering > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,988 B2 - Document ID: US7610988B2 - Status: Granted - Kind: B2 - Application number: 11/061,559 - Filed: 2005-02-18 - Published: 2005-09-22 - Granted: 2009-11-03 - Earliest claimed: 2004-02-27 - Assignees: Sauer-Danfoss ApS - Inventors: Bendt Porskrog; Kjeld Buus Jensen; Finn Visgaard Nielsen; Svend Erik Thomsen - Web page: https://patentgrep.com/patent/US7610988B2 ## CPC - B62D 1/286: {Systems for interrupting non-mechanical steering due to driver intervention} - B62D 5/093: Telemotor driven by steering wheel movement (hydraulic steering gear B62D3/14) - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract The invention concerns a hydraulic steering with a steering initiator, a steering unit with feedback properties, which can be activated by the steering initiator, the steering unit having a supply connection arrangement with a pressure connection (P) and a tank connection (T) and a working connection arrangement with two working connections (L, R), an auxiliary-force operated steering valve, which is located in parallel with the steering unit between the supply connection arrangement (P, T) and the working connection arrangement (L, R), and a feedback suppressing device, which is active, when the steering valve is active. It is endeavored to find a simple manner of ensuring the priority of the steering initiator over the steering valve. For this purpose, the steering initiator interacts with an activation sensor, which deactivates the feedback suppressing device on an activation of the steering initiator. ## Claims ### Claim 1 A hydraulic steering with a steering initiator, a steering unit with feedback properties, which can be activated by the steering initiator, the steering unit fluidly connecting a supply connection arrangement with a pressure connection and a tank connection to a working connection arrangement with two working connections, an auxiliary-force operated steering valve, which is located in parallel with the steering unit between the supply connection arrangement and the working connection arrangement, and a feedback suppressing device, which is active, when the steering valve is active, wherein the steering initiator receives feedback from the working connection arrangement only through the steering unit and interacts with an activation sensor, which deactivates the feedback suppressing device on an activation of the steering initiator. ### Claim 2 (depends on 1) The steering in accordance with claim 1, wherein the steering initiator exists in the form of a steering handwheel, which is connected with the steering unit via a steering shaft, the activation sensor determining an activation of the steering handwheel. ### Claim 3 (depends on 2) The steering in accordance with claim 2, wherein the activation sensor interacts with the steering shaft. ### Claim 4 (depends on 2) The steering in accordance with claim 2, wherein the activation sensor is a torque sensor. ### Claim 5 (depends on 2) The steering in accordance with claim 2, wherein the activation sensor is a rotation angle sensor. ### Claim 6 (depends on 1) The steering in accordance with claim 1, wherein the feedback suppressing device has a brake, which acts upon the steering initiator. ### Claim 7 (depends on 6) The steering in accordance with claim 6, wherein the steering initiator is a steering handwheel, and wherein the brake acts upon the steering handwheel via a steering shaft. ### Claim 8 (depends on 7) The steering in accordance with claim 7, wherein the activation sensor is located between the brake and the steering handwheel. ### Claim 9 (depends on 6) The steering in accordance with claim 6, wherein the brake is an electrically activated brake. ### Claim 10 (depends on 6) The steering in accordance with claim 6, wherein the brake generates a maximum braking torque of 8 Nm. ### Claim 11 A hydraulic steering comprising: a steering arrangement fluidly connecting a supply connection arrangement, having a pressure connection and a tank connection, to a working connection arrangement, and receiving feedback from the working connection arrangement; a steering initiator connected to activate the steering arrangement, and receiving feedback from the working connection arrangement only through the fluid connections of the steering arrangement; an auxiliary-force operated steering valve, fluidly connecting the supply connection arrangement to the working connection arrangement in parallel with the steering arrangement; a feedback suppressing device, which is active when the steering valve is active; and an activation sensor interacting with the steering initiator to deactivate the feedback suppressing device on an activation of the steering initiator. ### Claim 12 (depends on 11) The hydraulic steering according to claim 11, wherein the steering arrangement is configured to provide a first pressure at the working connection arrangement, the steering valve is configured to provide a second pressure at the working connection arrangement, and the first pressure is larger than the second pressure. ### Claim 13 (depends on 11) The hydraulic steering according to claim 11, wherein the feedback suppressing device is a brake connected to restrain the steering initiator. ### Claim 14 (depends on 13) The hydraulic steering according to claim 13, wherein the activation sensor is disposed between the feedback suppressing device and the steering initiator. ### Claim 15 (depends on 13) The hydraulic steering according to claim 13, wherein the activation sensor senses torque on the steering initiator. ### Claim 16 (depends on 13) The hydraulic steering according to claim 13, wherein the activation sensor senses rotation of the steering initiator.