Patent 9133837

Prior art

Earlier patents, publications, and products that may anticipate or render the claims unpatentable.

Active provider: Google · gemini-2.5-flash

Prior art

Earlier patents, publications, and products that may anticipate or render the claims unpatentable.

✓ Generated

The USPTO database confirms that US patent 9133837, titled "Method of controlling a hydraulic system," is currently Active and is projected to expire on March 13, 2034.

Here is an analysis of the most relevant prior art cited in US patent 9133837, focusing on potential anticipation under 35 U.S.C. § 102:

Prior Art Citations and Potential Anticipation:

The patent text explicitly mentions U.S. Pat. No. 5,525,043 ('043 patent) as relevant background art.

  • U.S. Pat. No. 5,525,043 (Lukich):
    • Full Citation: US5525043A.
    • Publication Date: 1996-06-11 (Filing Date: 1993-12-23).
    • Brief Description: This patent describes a hydraulic control system designed to reduce engine lug. It uses multiple sensors to detect various operating parameters of the hydraulic system (including the pump and engine) to calculate a parameter signal indicating engine load. When the engine load exceeds a predefined level, the displacement of the variable displacement pump is reduced, allowing the engine speed to increase to a predefined level.
    • Potential Anticipation of Claims: The '043 patent broadly addresses controlling hydraulic systems to prevent engine lug by adjusting pump displacement based on engine load. This could potentially anticipate aspects of Claim 1, Claim 11, and Claim 15, particularly the concept of sensing engine speed and adjusting pump output to prevent engine lug. However, US9133837B2 distinguishes itself by focusing on a simpler methodology that directly compares desired power to an allowable power determined from a map, aiming for reduced complexity and cost compared to the '043 patent's "number of operating parameters" and "minimum amount of oscillation" approach.

Beyond the specifically discussed '043 patent, US9133837B2 also lists several other prior art documents. A selection of these are analyzed below for their relevance to the independent claims (Claim 1, Claim 11, and Claim 15):

  • US3877839A (Ifield):

    • Full Citation: US3877839A.
    • Publication Date: 1975-04-15 (Filing Date: 1972-10-23).
    • Brief Description: This patent describes "Torque limiting means for variable displacement pumps".
    • Potential Anticipation of Claims: This patent could potentially anticipate aspects of Claim 1, Claim 11, and Claim 15, specifically the concept of limiting the power or torque of a variable displacement pump. The core idea of setting a maximum allowable output for the pump based on operational parameters, even if those parameters differ, aligns with the fundamental control objective.

  • US4395199A (Hitachi Construction Machinery Co., Ltd.):

    • Full Citation: US4395199A.
    • Publication Date: 1983-07-26 (Filing Date: 1979-10-15).
    • Brief Description: This patent details a "Control method of a system of internal combustion engine and hydraulic pump".
    • Potential Anticipation of Claims: Given its title, this patent likely covers methods for controlling hydraulic pumps driven by internal combustion engines, which is central to all independent claims of US9133837B2. It could potentially anticipate aspects of detecting engine speed, determining desired power, identifying allowable power, and adjusting the pump, depending on the specific control logic disclosed.

  • US4534707A (Caterpillar Tractor Co.):

    • Full Citation: US4534707A.
    • Publication Date: 1985-08-13 (Filing Date: 1984-05-14).
    • Brief Description: This patent is for a "Hydrostatic vehicle control".
    • Potential Anticipation of Claims: While broader, a hydrostatic vehicle control system inherently manages engine power distribution to hydraulic components. It might anticipate elements of engine speed detection and power allocation in a hydraulic system, thus potentially impacting claims 1, 11, and 15, especially if it describes methods of limiting hydraulic power to prevent engine overload.

  • US4606313A (Hitachi Construction Machinery Co., Ltd.):

    • Full Citation: US4606313A.
    • Publication Date: 1986-08-19 (Filing Date: 1980-10-09).
    • Brief Description: This patent describes a "Method of and system for controlling hydraulic power system".
    • Potential Anticipation of Claims: Similar to US4395199A, this patent directly relates to controlling hydraulic power systems, a core element of all independent claims. The specific control methodology would need to be examined to determine the extent of anticipation, particularly regarding the use of maps for allowable power values and the comparison with desired power.

  • US5050379A (Kabushiki Kaisha Toyoda Jidoshokki Seisakusho):

    • Full Citation: US5050379A.
    • Publication Date: 1991-09-24 (Filing Date: 1990-08-23).
    • Brief Description: This patent describes "Displacement of a variable displacement hydraulic pump and speed of an engine driving the pump controlled based on demand".
    • Potential Anticipation of Claims: This patent's description strongly aligns with the core concepts of US9133837B2, specifically the control of a variable displacement pump and engine speed based on demand. It could potentially anticipate all independent claims, particularly the steps of determining a desired power value (based on demand), detecting engine speed, and adjusting pump displacement. The novelty of US9133837B2 might reside in the explicit use of an "allowable power value" derived from a "map" and the specific comparison logic.

  • US5214916A (Caterpillar Inc.):

    • Full Citation: US5214916A.
    • Publication Date: 1993-06-01 (Filing Date: 1992-01-13).
    • Brief Description: This patent is titled "Control system for a hydraulic work vehicle".
    • Potential Anticipation of Claims: As it describes a control system for a hydraulic work vehicle, it likely involves managing engine and hydraulic pump interactions. This could potentially anticipate elements of Claim 1 and Claim 11, particularly regarding the system architecture and the general idea of controlling a hydraulic pump coupled to an engine.

  • US5295353A (Kabushiki Kaisha Komatsu Seisakusho):

    • Full Citation: US5295353A.
    • Publication Date: 1994-03-22 (Filing Date: 1990-06-06).
    • Brief Description: This patent describes a "Controlling arrangement for travelling work vehicle".
    • Potential Anticipation of Claims: This patent could potentially anticipate aspects of Claim 1, Claim 11, and Claim 15 by describing a control arrangement for a work vehicle that likely includes hydraulic systems and engine management, especially concerning how power is supplied to implements or traction.

  • US5477679A (Hitachi Construction Machinery Co., Ltd.):

    • Full Citation: US5477679A.
    • Publication Date: 1995-12-26 (Filing Date: 1990-10-16).
    • Brief Description: This patent describes an "Apparatus for controlling revolution speed of prime mover for hydraulically propelled work vehicle".
    • Potential Anticipation of Claims: This patent's focus on controlling the revolution speed of a prime mover (engine) for a hydraulically propelled vehicle directly relates to the engine speed detection and control aspects of US9133837B2. It could potentially anticipate Claim 1 and Claim 15, particularly the steps involving sensing engine speed and adjusting hydraulic output to maintain engine performance.

  • US5576962A (Caterpillar Inc.):

    • Full Citation: US5576962A.
    • Publication Date: 1996-11-19 (Filing Date: 1995-03-16).
    • Brief Description: This patent is titled "Control system and method for a hydrostatic drive system".
    • Potential Anticipation of Claims: This patent, from the same assignee, concerns controlling hydrostatic drive systems, which are a type of hydraulic system. It could potentially anticipate aspects of all independent claims related to system control, method of control, and system components, especially if it describes managing power between an engine and a hydraulic pump to optimize performance or prevent lugging.

  • US5934879A (Hitachi Construction Machinery Co., Ltd.):

    • Full Citation: US5934879A.
    • Publication Date: 1999-08-10 (Filing Date: 1995-12-22).
    • Brief Description: This patent is for a "Pump torque control system".
    • Potential Anticipation of Claims: This patent directly addresses pump torque control, which is a form of power control for a pump. It could potentially anticipate claims 1, 11, and 15, particularly the concept of controlling the power value of the pump. The specific method of control and how allowable torque is determined would be critical in assessing the extent of anticipation.

  • US5951258A (Caterpillar Inc.):

    • Full Citation: US5951258A.
    • Publication Date: 1999-09-14 (Filing Date: 1997-07-09).
    • Brief Description: This patent is for a "Torque limiting control system for a hydraulic work machine".
    • Potential Anticipation of Claims: Another patent from Caterpillar Inc., this one specifically describes a "torque limiting control system" for a hydraulic work machine. This is highly relevant to US9133837B2's concept of an "allowable power value" (which can be torque) and adjusting the pump to deliver a selected power value. It could potentially anticipate all independent claims, particularly the mechanism of limiting power to avoid overloading the engine.

  • US6010309A (Komatsu Ltd.):

    • Full Citation: US6010309A.
    • Publication Date: 2000-01-04 (Filing Date: 1997-01-31).
    • Brief Description: This patent describes a "Control device for variable capacity pump".
    • Potential Anticipation of Claims: The control of a variable capacity (displacement) pump is a fundamental aspect of US9133837B2. This patent could potentially anticipate elements of all independent claims related to adjusting the pump to deliver a specific power value or displacement, depending on the control logic used in the prior art.

  • US6021756A (Hitachi Construction Machinery Co., Ltd.):

    • Full Citation: US6021756A.
    • Publication Date: 2000-02-08 (Filing Date: 1997-05-27).
    • Brief Description: This patent describes an "Engine control system for construction machine".
    • Potential Anticipation of Claims: This patent's focus on an engine control system for a construction machine, which typically employs hydraulic implements, could potentially anticipate aspects of Claim 1, Claim 11, and Claim 15. The specific methods of engine and hydraulic pump coordination would determine the degree of anticipation.

Generated 5/27/2026, 12:45:58 PM