Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments with respect to claim(s) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Objections
Claim 17 objected to because of the following informalities:
Claim 17, line 2, “control circuity” should read --control circuitry-- to remedy a typographical error.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 7 and 17 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Oasa (US 11125327).
Oasa discloses:
7. A work vehicle (1) comprising: a vehicle body (2); a first traveling device (wheels 4) provided on the vehicle body; a first hydraulic motor (33) having a first motor pilot port (port connected to 35a) and configured to drive the first traveling device in response to a first motor pilot pressure applied to the first motor pilot port (Col. 6, motor 33 includes a displacement control device 35 that adjusts the rotation of the traveling motor 33 which drives the first traveling device 4 through shaft 37);
a first hydraulic pump (31) having a first pump pilot port (a port connected to 46) and configured to supply hydraulic fluid to the first hydraulic motor in response to a first pump pilot pressure applied to the first pump pilot port (Col. 7 lines 1-18);
a first oil passage (32a) and a second oil passage (32b) which connect the first hydraulic pump and the first hydraulic motor and through which the hydraulic fluid is supplied;
a first hydraulic pressure sensor (34a) configured to detect a first hydraulic pressure in the first oil passage; a second hydraulic pressure sensor (34b) configured to detect a second hydraulic pressure in the second oil passage;
a pilot pump (38) configured to supply pilot oil to the first pump pilot port; an engine (21) configured to drive the first hydraulic pump and the pilot pump; and
control circuitry configured to obtain an absolute value of a first differential pressure, which is a difference between the first hydraulic pressure and the second hydraulic pressure (Col. 7 lines 8-23 discloses the two pressure signals, Col. 16 lines 53-67 discloses using the absolute value of the differential pressure dP within the control of the displacement of the pump 31),
the control circuity being configured to regulate at least one of the first pump pilot pressure and a rotational speed of the engine such that a vehicle speed is controlled to maintain a predetermined target speed according to the absolute value of the first differential pressure (
S102, controller 72 determines a target vehicle speed from the accelerator operation amount,
S202 discloses the controller 72 calculating the difference between the target vehicle speed and the actuator vehicle speed
S304 controller determines a target differential pressure from the target motor torque, the pressure differential is the pressure difference between line 32a and 32b
S305 discloses the controller 72 determining the target flow rate of the pump from the differential pressure
S703 discloses the controller 72 determining a target engine speed from the target vehicle speed
S106, discloses determining a target displacement of the pump 31 from the target vehicle speed
Col. 16 lines 53-67 discloses using the absolute value of the differential pressure dP within the control of the displacement of the pump 31;
Col. 16 lines 21-29 discloses controller 72 outputting a command signal to control the engine to operate at the target engine speed, a command signal to the pump displacement control device 45 to drive the pump 31 at the target displacement to achieve a target vehicle speed which indicates that a vehicle speed is maintained at the target vehicle speed in accordance with an absolute value of a HST differential pressure since the control targets of the components are determined from a desired vehicle speed and uses the absolute value of the HST differential pressure in the control scheme)
17. (New) The work vehicle according to claim 7, wherein the control circuity is configured to regulate the at least one of the first pump pilot pressure and the rotational speed of the engine by increasing the at least one of the first pump pilot pressure and the rotational speed of the engine as the absolute value of the first differential pressure increases such that the vehicle speed is controlled to maintain the predetermined target speed according to the absolute value of the first differential pressure (S305, Col. 12 line 18-28 discloses increasing the flow rate of the pump according to an increase in a target differential pressure and S403; S703, Col. 15 lines 19-23 discloses increasing a target engine speed according to an increase in a target vehicle speed, which is determined by the HST differential pressure).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Oasa in view of Du (US 8596057).
Regarding claim 11, Oasa discloses the work vehicle according to claim 7, further comprising: a traveling instruction input device (61, 62, 63) to which an instruction of a traveling direction is input by a user; an operation valve (47) configured to be operated by the travel instruction input device to regulate the first pump pilot pressure; a secondary pilot oil passage connecting the operation valve and the first pump pilot port (valve 47 includes two pilot oil passages that connect to a pump pilot port of 46).
Oasa does not disclose a secondary pressure control valve provided in the secondary pilot oil passage and configured to regulate a secondary pilot pressure which is a hydraulic pressure of the pilot oil in the secondary pilot oil passage.
However, Du discloses a work vehicle including a hydrostatic transmission similar to Oasa and the present application and therefore constitutes analogous art. Du discloses a pump (22) that supplies fluid to a hydraulic motor (24), and discloses a pump displacement adjustment mechanism (Fig. 3) that includes a first pressure control valve (40) and a second pressure control valve (42) that are provided in a first and second pilot oil passage and are connected to pilot pump 28 and used to control a swashplate displacement of the pump to adjust the fluid output of the pump (Col. 2).
Since simple substitution is an exemplary rationale that supports a conclusion of obviousness, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified the system of Oasa to have simply substituted its single pilot pressure control valve 47 and mechanism 43 with the pilot pressure control configuration wherein a first and second pressure control valves are provided in the pilot oil passage connected to a pump pilot port to control a pressure of the pilot oil to control the pump swashplate displacement as taught by Fig.3 of Du to yield only the expected result of being able to control a pump swashplate displacement in a work vehicle. In light of the modification by Du, the control circuitry of Oasa would being configured to control both the first pressure control valve as well as the secondary pressure control valves to convert the first pump pilot pressure to the secondary pilot pressure such that the vehicle speed is controlled to maintain the target speed.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Oasa in view of Morita et al. (US 4395878).
Regarding claim 15, Oasa discloses the work vehicle according to claim 7, but does not disclose further comprising: a second traveling device provided on the vehicle body opposite to the first traveling device; a second hydraulic motor having a second motor pilot port and configured to drive a second traveling device according to a second motor pilot pressure applied to the second motor pilot port; a second hydraulic pump having a second pump pilot port and configured to supply hydraulic fluid to the second hydraulic motor in response to a second pump pilot pressure applied to the second pump pilot port; a third oil passage and a fourth oil passage which connect the second hydraulic pump and the second hydraulic motor and through which the hydraulic fluid is supplied; a third hydraulic pressure sensor configured to detect a third hydraulic pressure in the third oil passage a fourth hydraulic pressure sensor configured to detect a fourth hydraulic pressure in the fourth oil passage; the engine being configured to drive the second hydraulic pump; the pilot pump being configured to supply the pilot oil to the second pump pilot port; the control circuitry being configured to obtain an absolute value of a second differential pressure which is a difference between the third hydraulic pressure and the fourth hydraulic pressure; and the control circuitry being configured to regulate at least one of the second pump pilot pressure and the rotational speed of the engine according to the absolute value of the first differential pressure such that the vehicle speed is controlled to maintain the predetermined target speed when the absolute value of the first differential pressure is larger than the absolute value of the second differential pressure.
However, Morita disclose a work vehicle having a hydrostatic transmission for traveling purposes similar to Oasa and the present application and therefore constitutes analogous art. Morita discloses a bidirectional variable displacement pump 2 that supplies fluid to a hydraulic traveling motor 14 which is analogous to how Oasa discloses a bidirectional 31 that supplies fluid to a hydraulic traveling motor 33. Morita further discloses a second identical system with bidirectional pump 4 that supplies fluid to a hydraulic traveling motor 16. Morita discloses that each HST circuit drives one side of the work vehicle traveling system and are used to steer the vehicle (Col. 1 lines 7-18).
Since using a pair of identical independent closed loops, each for driving one side of the tracks or wheels is a known technique in the art, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified the system of Oasa to have used an identical closed loop system as seen in Oasa’s Fig. 2 to drive a second traveling device provided on the vehicle body opposite to the first traveling device as taught by Morita to yield only the expected results of a work vehicle traveling system that allows for independent control of each half of the vehicle. One of ordinary skill in the art would recognize that this would allow for a zero turn radius operation for the work machine which is beneficial for an operator. The resulting system of Oasa in view of Morita would result in a second traveling device provided on the vehicle body opposite to the first traveling device; a second hydraulic motor having a second motor pilot port and configured to drive a second traveling device according to a second motor pilot pressure applied to the second motor pilot port; a second hydraulic pump having a second pump pilot port and configured to supply hydraulic fluid to the second hydraulic motor in response to a second pump pilot pressure applied to the second pump pilot port; a third oil passage and a fourth oil passage which connect the second hydraulic pump and the second hydraulic motor and through which the hydraulic fluid is supplied; a third hydraulic pressure sensor configured to detect a third hydraulic pressure in the third oil passage a fourth hydraulic pressure sensor configured to detect a fourth hydraulic pressure in the fourth oil passage; the engine being configured to drive the second hydraulic pump; the pilot pump being configured to supply the pilot oil to the second pump pilot port; the control circuitry being configured to obtain an absolute value of a second differential pressure which is a difference between the third hydraulic pressure and the fourth hydraulic pressure; and the control circuitry being configured to regulate at least one of the second pump pilot pressure and the rotational speed of the engine according to the absolute value of the first differential pressure such that the vehicle speed is controlled to maintain the predetermined target speed when the absolute value of the first differential pressure is larger than the absolute value of the second differential pressure.
Allowable Subject Matter
Claim 12 or 16 objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
The prior art does not appear to disclose nor render obvious the limitations of claims 12 or 16 in combination with their base claim limitations.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Oasa (US 11199260) discloses a work vehicle similar to Du and the present application and therefore constitutes analogous art. Oasa discloses determining a target differential pressure from a target traction force.
Oasa discloses: a work vehicle (1) comprising: a vehicle body (2); a first traveling device (wheels 4) provided on the vehicle body; a first hydraulic motor (33) having a first motor pilot port (port connected to 35a) and configured to drive the first traveling device in response to a first motor pilot pressure applied to the first motor pilot port (Col. 7, motor 33 includes a displacement control device 35 that adjusts the rotation of the traveling motor 33 which drives the first traveling device 4 through shaft 37);
a first hydraulic pump (31) having a first pump pilot port (a port connected to 46) and configured to supply hydraulic fluid to the first hydraulic motor in response to a first pump pilot pressure applied to the first pump pilot port (Col. 8 lines 16-24);
a first oil passage (32a) and a second oil passage (32b) which connect the first hydraulic pump and the first hydraulic motor and through which the hydraulic fluid is supplied;
a first hydraulic pressure sensor (34a) configured to detect a first hydraulic pressure in the first oil passage; a second hydraulic pressure sensor (34b) configured to detect a second hydraulic pressure in the second oil passage;
a pilot pump (38) configured to supply pilot oil to the first pump pilot port; an engine (21) configured to drive the first hydraulic pump and the pilot pump; and
control circuitry configured to obtain an absolute value of a first differential pressure, which is a difference between the first hydraulic pressure and the second hydraulic pressure (Col. 7 lines 8-23 discloses the two pressure signals, S304 discloses the pressure differential),
the control circuity being configured to regulate at least one of the first pump pilot pressure and a rotational speed of the engine such that a vehicle speed is controlled to maintain a predetermined target speed according to the absolute value of the first differential pressure (Col. 8 lines 32-48 discloses pump control valve 47 being controlled to adjust the pilot pressure supplied to the pump displacement actuator 46 which adjusts the amount of fluid output by the pump supplied to the motor to control the speed and direction of the wheels).
Du et al. (US 7536856) discloses a work vehicle comprising: a vehicle body (implicitly disclosed as the hydraulic system must be mounted on some sort of vehicle body); a first traveling device (50) provided on the vehicle body; a first hydraulic motor (16);
a first hydraulic pump (14) having a first pump pilot port (ports connected to 20) and configured to supply hydraulic fluid to the first hydraulic motor in response to a first pump pilot pressure (pressure output from 34) applied to the first pump pilot port;
a first oil passage (15a) and a second oil passage (15b) which connect the first hydraulic pump and the first hydraulic motor and through which the hydraulic fluid is supplied;
a first hydraulic pressure sensor (106) configured to detect a first hydraulic pressure in the first oil passage; a second hydraulic pressure sensor (108) configured to detect a second hydraulic pressure in the second oil passage;
a pilot pump (34) configured to supply pilot oil to the first pump pilot port; an engine (12) configured to drive the first hydraulic pump and the pilot pump;
the control circuity being configured to regulate at least one of the first pump pilot pressure and a rotational speed of the engine such that a vehicle speed is controlled to maintain a predetermined target speed according to the absolute value of the first differential pressure (Col. 5 lines 14-36 discloses operator using interface device 102 to input a desired power output to be delivered to load 50
Col. 5 lines 53-67 discloses controlling valve 32 to establish an appropriate pressure differential across piston 24 to achieve a desired output of hydraulic actuator 16
Col. 6 line 43-45 discloses controlling speed output as desired
Col. 7 discloses controller 104 receiving signals from pressure sensors 106, 108 to maintain the desired power output of the transmission 18, and discloses that the desired power output may include a torque and speed component.
Col. 7 discloses controlling the power source (engine) 12 to maintain a desired rotational speed output.
Col. 7 discloses load 50 being formed as traction devices propelling a work machine, and discloses maintaining a desired speed of output of system 10, which indicates a vehicle speed.)
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Dustin T Nguyen whose telephone number is (571)270-0163. The examiner can normally be reached M - F: 8:00am - 4:30pm.
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/DUSTIN T NGUYEN/Primary Examiner, Art Unit 3745 August 24, 2026
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