DETAILED ACTION
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 Amendment
Applicant's submission filed on 11/17/2025 has been entered. Claims 1-20 remain(s) pending in the application. Applicant's amendments to the Claims have overcome each and every objection previously set forth in the Non-Final Office Action mailed 09/11/2025, hereinafter NFOA2.
Response to Arguments
Applicant’s arguments, with respect to the rejection(s) of claim(s) 1, 16 and 17 under 35 U.S.C. 103 as being unpatentable over Helbling; Frank et al. US 20090044872 A1, hereinafter Helbling, in view of Entwistle; Richard Thomas et al. US 7770687 B2, hereinafter Entwistle, in further view of Erikksson; Björn et al. US 20190257328 A1, hereinafter Erikksson, have been fully considered but are not persuasive. The applicant argues that the modified device of Helbling/Entwistle/Erikksson, specifically Erikksson, fails to disclose the newly amended subject matter: “wherein each of the first to fourth fail-safe solenoid-controlled pilot valves has a normally closed internal drain passage”. As [0042] of Erikksson was cited in the NFOA2, the applicant argues that the drain path described is not a “normally closed internal drain passage” due to its operation being “incidental’. The applicant further argues that ‘this connection between an internal fluid line of the spool and a surrounding cavity… such fluid path is not part of a normally closed internal drain passage that is configured to automatically open in response to spool failure.
In response, [0042] discloses an internal fluid path that is normally closed during normal operation of the spool/valve. It is closed due to a connection between the spool and the spool actuator. However, when the spool gets stuck, the spool actuator disconnects from the spool, automatically opening the internal fluid path such that drainage of the pilot pressure fluid supplied from the pilot pressure fluid supply system may occur. The argument that this action does not qualify because it is ‘incidental’ or an ‘un-intended consequence’ even if accurate, is does not negate the fact that the action happens. To summarize, [0042] discloses an internal passage that is normally closed until a failure event (spool gets stuck), at which point the internal passage automatically opens for drainage of the pilot pressure fluid. This directly reads on the claim language.
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 of this title, 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.
Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Helbling; Frank et al. US 20090044872 A1, hereinafter Helbling, in view of Entwistle; Richard Thomas et al. US 7770687 B2, hereinafter Entwistle, in further view of Erikksson; Björn et al. US 20190257328 A1, hereinafter Erikksson. The references is/are considered analogous art to the claimed invention because the references is/are from the same field of endeavor as the claimed invention (vehicle hydraulic systems). MPEP2141.01(a) I.
Regarding claim 1, Helbling discloses (Fig. 1-2) a redundant hydraulic system comprising:
a hydraulic fluid pressure source (56),
a hydraulic fluid reservoir (58),
a hydraulically driven actuator (“hydraulic consumer” [0031]) having a first chamber and a second chamber (of the consumer, each fundamentally connected to a port (22, 23)),
a redundant sectional or monoblock valve assembly (1) having a first pilot-operated directional control valve (54), each including:
an inlet port (10) fluidly connected for receiving high-pressure hydraulic fluid from the hydraulic fluid pressure source [0031],
an outlet port (12, 13) fluidly connected for draining hydraulic fluid to the hydraulic fluid reservoir [0031],
a first actuator port (22) fluidly coupled with the first chamber of the hydraulically driven actuator [0031],
a second actuator port (23) fluidly coupled with the second chamber of the hydraulically driven actuator [0031], and
a pilot operated flow control spool (26) arranged in a spool bore (25) [0031],
a first fail-safe solenoid-controlled pilot valve (60) operably connected to the first directional control valve and configured for driving the flow control spool in a first direction [0049],
a second fail-safe solenoid-controlled pilot valve (61) operably connected to the first directional control valve and configured for driving the flow control spool in a second direction [0049], and
redundant pilot pressure fluid supply system (18) having a first pilot pressure fluid supply line (18 left branch) and a second pilot pressure fluid supply line (18 right branch) configured for supplying pilot pressure fluid to the first to second fail-safe solenoid-controlled pilot valves [0049], wherein
each of the first to second fail-safe solenoid-controlled pilot valves has a drain passage (20, 68)) that is configured to open for enabling drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state ([0046] discloses forcing the control spool back to its original position and opening a drain passage for enabling automatic drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event the associated pilot spool is stuck in an actuated state).
Helbling fails to explicitly state that the valve assembly further comprises a second pilot-operated directional control valve, and the system further comprises a third fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the first direction, a fourth fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the second direction.
Entwistle discloses (Fig. 1) a redundant hydraulic system comprising:
a hydraulic fluid pressure source (15, 21),
a hydraulic fluid reservoir (11),
a hydraulically driven actuator (3) having a first chamber and a second chamber (depicted top and bottom chamber of (3)),
a redundant sectional or monoblock valve assembly (1) having a first pilot-operated directional control valve (5a) and a second pilot-operated directional control valve (5b), each including:
an inlet port (10a) fluidly connected for receiving high-pressure hydraulic fluid from the hydraulic fluid pressure source (Col 3 Ln 60-64),
an outlet port (10b) fluidly connected for draining hydraulic fluid to the hydraulic fluid reservoir (Col 3 Ln 60-64),
a first actuator port (9a) fluidly coupled with the first chamber of the hydraulically driven actuator (Col 3 Ln 60-64),
a second actuator port (9b) fluidly coupled with the second chamber of the hydraulically driven actuator (Col 3 Ln 60-64), and
a pilot operated flow control spool (6) arranged in a spool bore (depicted bore housing (6)) ,
a first fail-safe solenoid-controlled pilot valve (23a) operably connected to the first directional control valve and configured for driving the flow control spool in a first direction (Col 4 Ln 16-26),
a third fail-safe solenoid-controlled pilot valve (23b) operably connected to the second directional control valve and configured for driving the flow control spool in the first direction (Col 4 Ln 16-26), and
redundant pilot pressure fluid supply system (14/20) having a first pilot pressure fluid supply line (14) and a second pilot pressure fluid supply line (20) configured for supplying pilot pressure fluid to the first to third fail-safe solenoid-controlled pilot valves (Col 4 Ln 20-26), wherein
each of the first to third fail-safe solenoid-controlled pilot valves has a drain passage (depicted passage connected to (T) and (32)).
Entwistle further discloses it is beneficial to provide a second pilot-operated directional control valve and associated solenoid-controlled pilot valves for the purpose of “For safety reasons, it is often necessary to provide several steering circuits or at least several steering valves in such steer-by-wire steering systems. If one of the steering valves does not work properly, the other steering valve is activated, so that the vehicle can still be steered” (Col 1 Ln 31-35).
It would have been obvious to one of ordinary skill in the art, at the time the invention was filed, to modify Helbling, by a second pilot-operated directional control valve and associated solenoid-controlled pilot valves, as taught by Entwistle, for safety reasons.
To further clarify the modification, Helbling was modified to duplicate its own pilot operated direction control valve and associated solenoid-controlled pilot valves resulting in a second pilot-operated directional control valve, a third fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the first direction, and a fourth fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the second direction. Entwistle is further used to teach the control thereof later claimed.
Helbling further fails to explicitly state that the normally closed internal drain passage opening for drainage of the pilot pressure when the pilot valve is stuck in an actuated state is automatic.
Erikksson discloses (Fig. 1) a fail-safe solenoid-controlled pilot valve (5) operably connected to a first directional control valve (9) and configured for driving the flow control spool in a first direction [0035-0036],
wherein the fail-safe solenoid-controlled pilot valves has a normally closed internal drain passage (“internal fluid line of the spool”) that is configured to automatically open for enabling automatic drainage of pilot pressure fluid supplied from a pilot pressure fluid supply system (13) in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state ([0042]).
It would have been obvious to one of ordinary skill in the art, at the time the invention was filed, to modify Helbling, by providing the fail-safe solenoid-controlled pilot valve configured to automatically open to drain the pilot pressure fluid supplied from the pilot pressure fluid supply system, as taught by Erikksson, for the purpose of enabling automatic drainage in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state.
To further clarify the modification, all of the fail-safe solenoid-controlled pilot valves are modified to be configured for automatic drainage.
Regarding claim 2, Entwistle discloses (Fig. 1) the hydraulic system further comprises an electronic control system (27/28) configured for operating the first and third pilot valves in parallel, and for operating the second and fourth pilot valves in parallel (Col 5 Ln 14-21).
Regarding claim 3, Entwistle discloses (Fig. 1) the hydraulic system comprises an electronic control system (27/28) that is configured for operating the first and second pilot-operated directional control valves in parallel (Col 5 Ln 14-21).
Regarding claim 4, Entwistle discloses (Fig. 1) the electronic control system is configured for simultaneously supplying same control signals to both the first and third pilot valves, and for simultaneously supplying same control to both the second and fourth pilot valves (Col 5 Ln 14-21).
Regarding claim 5, Helbling discloses (Fig. 1-2) an inlet port of each of the first and second fail-safe solenoid-controlled pilot valves is connected to the first pilot pressure fluid supply line, and an inlet port of each of the third and fourth fail-safe solenoid-controlled pilot valves is connected to the second pilot pressure fluid supply line (as depicted by Fig. 2, an exemplary layout is disclosed whereby a first/second pilot valve is connected to the left pilot line, and a third/fourth pilot valve is connected to the right pilot line), or wherein
Entwistle also discloses (Fig. 1) the first pilot pressure fluid supply line (14) is connected to a first input port (14) of a shuttle valve (13) and the second pilot pressure fluid supply line (20) is connected to a second input port (20) of the shuttle valve, and an inlet port of each of the first to fourth fail-safe solenoid-controlled pilot valves is connected to an outlet port (12) of the shuttle valve.
In the event that Entwistle is required (second claimed embodiment) it would have been obvious to one of ordinary skill in the art, at the time the invention was filed, to modify Helbling, by providing the shuttle valve, and pressure supplies/pumps, as taught by Entwistle, for safety reasons (Col 3 Ln 5-6).
Regarding claim 6, Entwistle discloses (Fig. 1) the redundant pilot pressure fluid supply system comprises a first pressure reducing valve (25a) configured for supplying pilot pressure fluid to the first pilot pressure fluid supply line, and a second pressure reducing valve (25b) configured for supplying pilot pressure fluid to the second pilot pressure fluid supply line (Col 4 Ln 22-24).
Regarding claim 7, Entwistle discloses (Fig. 1) an inlet port of each of the first and second pressure reducing valves is fluidly connected for receiving high-pressure hydraulic fluid from the hydraulic fluid pressure source (15), or for receiving pilot pressure fluid from a dedicated pilot pressure pump (21, Col 3 Ln 65 – Col 4 Ln 15).
Regarding claim 8, Helbling discloses (Fig. 1-2) the hydraulic system is free from a valve and/or electronic control system configured for actively selectively setting one of the first and second pilot-operated directional control valves in an active state and/or setting the other of the first and second pilot-operated directional control valves in a non-active state in response to a detected malfunction of a part of the hydraulic system (the depicted system is disclosed as free from active/non-active state settings associated with malfunctions).
Regarding claim 9, Entwistle discloses (Fig. 1) a connection point connecting the first actuator port of the first pilot-operated directional control valve (5a) with the first actuator port of the second pilot-operated directional control valve (5b) is located within the valve assembly, in particular within an input section or end section, or outside of the valve assembly (as depicted, the connection point is within the dashed box of (1)).
Regarding claim 10, Helbling discloses (Fig. 1-2) the first and second pilot-operated directional control valves have the same design and functionality ((5a/5b) are disclosed/depicted as being identical in form and function).
Regarding claim 11, Helbling discloses (Fig. 1-2) the valve assembly is a redundant sectional valve assembly, wherein the first pilot-operated directional control valve is assembled in a first individual work section, wherein the second pilot-operated directional control valve is assembled in a second individual work section, wherein each of the first and second work sections include said inlet port fluidly connected for receiving high-pressure hydraulic fluid from the hydraulic fluid pressure source, said outlet port fluidly connected for draining hydraulic fluid to the hydraulic fluid reservoir, said first actuator port fluidly coupled with the first chamber of the hydraulically driven actuator, said second actuator port fluidly coupled with the second chamber of the hydraulically driven actuator, and said pilot operated flow control spool arranged in a spool bore, and wherein said first and second individual work sections are stacked and clamped together to provide the assembled sectional valve assembly (Fig. 1 and [0030] indicated that the valve assembly is a ‘directional valve disk such as is used in a hydraulic control block’, one of ordinary skill would understand that each valve assembly may be assembled in individual work sections, or in a monoblock assembly; in the case wherein the valve assemblies being individual work sections fundamentally requires some form of stacking and/or attachment to form the hydraulic control block).
Regarding claim 12, Helbling discloses (Fig. 1-2) the sectional valve assembly further comprises a inlet section (such as (30)) and an end section (such as (31)), wherein the inlet section, the first individual work section, the second individual work section and the end section are stacked and clamped together to provide the assembled sectional valve assembly, and wherein the inlet section and/or end section includes an inlet port and an outlet port (Fig. 1 and [0030] indicated that the valve assembly is a ‘directional valve disk such as is used in a hydraulic control block’, one of ordinary skill would understand that each valve assembly may be assembled in individual work sections, or in a monoblock assembly; in the case wherein the valve assemblies being individual work sections fundamentally requires some form of stacking and/or attachment to form the hydraulic control block).
Regarding claim 13, Helbling discloses (Fig. 1-2) the first and second pressure reducing valves and the shuttle valve is located in the inlet section (30).
Regarding claim 14, Helbling discloses (Fig. 1-2) the valve assembly is redundant monoblock valve assembly having a one-piece block with integrally formed inlet port and an outlet port, and with the first and second pilot-operated directional control valves formed either integrally in the block or clamped to a surface of the block (Fig. 1 and [0030] indicated that the valve assembly is a ‘directional valve disk such as is used in a hydraulic control block’, one of ordinary skill would understand that each valve assembly may be assembled in individual work sections, or in a monoblock assembly; in the case wherein the valve assemblies being individual work sections fundamentally requires some form of stacking and/or attachment to form the hydraulic control block).
Regarding claim 15, Helbling discloses (Fig. 1-2) a vehicle comprising wheels and/or crawlers for facilitating movement of the vehicle and a solenoid-controlled control system comprising a redundant hydraulic system according to claim 1, wherein the at least one hydraulic actuator is configured to be used for steering the vehicle [0002].
Regarding claim 16, Helbling discloses (Fig. 1-2) a method for operating a hydraulically driven actuator of a redundant hydraulic system, the method comprises:
providing a hydraulic system that comprises: a hydraulic actuator; a first pilot-operated directional control valve connected to the hydraulic actuator and a second pilot-operated directional control valve also connected to the hydraulic actuator; first and second fail-safe solenoid-controlled pilot valves operatively connected to the first pilot-operated directional control valve, and third and fourth fail-safe solenoid-controlled pilot valves operatively connected to the second pilot-operated directional control valve (see the modified device of Helbling/Entwistle of claim 1 above);
energizing a solenoid of the first fail-safe solenoid-controlled pilot valve for displacing an associated pilot spool forwards, such that a flow passage opens that supplies pilot pressure fluid from a redundant pilot pressure fluid supply system to a first longitudinal end of a flow control spool of the first directional control valve, and such that high-pressure hydraulic fluid from an external hydraulic fluid pressure source is routed to a first chamber of the hydraulically driven actuator via the first directional control valve (Helbling discloses said energizing/control of (54) in [0049] , and
substantially simultaneously energizing a solenoid of the third fail-safe solenoid-controlled pilot valve for displacing an associated pilot spool forwards, such that a flow passage opens that supplies pilot pressure fluid from the redundant pilot pressure fluid supply system to a first longitudinal end of a flow control spool of the second directional control valve, and such that high-pressure hydraulic fluid from the external hydraulic fluid pressure source is routed to said first chamber of the hydraulically driven actuator via the second directional control valve (Entwistle discloses (Col 5 Ln 14-21) simultaneous control of duplicate valves); and
stopping energizing the solenoid of the first fail-safe solenoid-controlled pilot valve, and substantially simultaneously stopping energizing the solenoid of the third fail-safe solenoid-controlled pilot valve (Entwistle discloses (Col 5 Ln 14-21) simultaneous control of duplicate valves).
Helbling fails to explicitly state that the method further comprises subsequent rearwards motion of a plunger of the solenoid of the first fail-safe solenoid-controlled pilot valve automatically causes opening of a normally closed internal drain passage in the first fail-safe solenoid-controlled pilot valve for enabling automatic drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event the associated pilot spool is stuck in an actuated state, and wherein subsequent rearwards motion of a plunger of the solenoid of the third fail-safe solenoid-controlled pilot valve causes opening of a drain passage in the third fail-safe solenoid-controlled pilot valve in the event the associated pilot spool is stuck in an actuated state. Instead Helbling discloses each of the first to second fail-safe solenoid-controlled pilot valves has a drain passage (20, 68)) that is configured to open for enabling drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state ([0046] discloses forcing the control spool back to its original position and opening a drain passage for enabling automatic drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event the associated pilot spool is stuck in an actuated state).
Erikksson discloses (Fig. 1) a fail-safe solenoid-controlled pilot valve (5) operably connected to a first directional control valve (9) and configured for driving the flow control spool in a first direction [0035-0036],
wherein subsequent rearwards motion of a plunger (“solenoid actuator”) of the solenoid of the first fail-safe solenoid-controlled pilot valve automatically causes opening of a normally closed internal drain passage (“internal fluid line of the spool”) in the first fail-safe solenoid-controlled pilot valve for enabling automatic drainage of pilot pressure fluid supplied from a pilot pressure fluid supply system (13) in the event the associated pilot spool is stuck in an actuated state [0042].
It would have been obvious to one of ordinary skill in the art, at the time the invention was filed, to modify Helbling, by providing the fail-safe solenoid-controlled pilot valve configured to automatically open to drain the pilot pressure fluid supplied from the pilot pressure fluid supply system, as taught by Erikksson, for the purpose of enabling automatic drainage in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state.
To further clarify the modification, all of the fail-safe solenoid-controlled pilot valves are modified to be configured for automatic drainage.
Regarding claim 17, Helbling discloses (Fig. 1-2) a hydraulic system for activating a hydraulic consumer [0031] having a first consumer port and a second consumer port, the system comprising:
a valve assembly (1) having a pressure source inlet port (10), a reservoir port (12, 13), a first pilot-operated directional control valve (54), each pilot-operated directional control valve including: a first port (10) fluidly connected to the pressure source inlet port, a second port (12, 13) fluidly connected to the reservoir port, a third port (22) fluidly connected to the first consumer port, a fourth port (23) fluidly connected to the second consumer port, and a pilot operated flow control spool (26) arranged in a spool bore (25) [0031],
a first fail-safe solenoid-controlled pilot valve (60)operably connected to the first directional control valve and configured for driving the flow control spool in a first direction [0049],
a second fail-safe solenoid-controlled pilot valve (61) operably connected to the first directional control valve and configured for driving the flow control spool in a second direction [0049], and
a pilot pressure fluid supply system (18) having a first pilot pressure fluid supply line (18 left branch) and a second pilot pressure fluid supply line (18 right branch) configured for supplying pilot pressure fluid to the first to second fail-safe solenoid-controlled pilot valves [0049], wherein
each of the fail-safe solenoid-controlled pilot valves has (20, 68)) that is configured to open for enabling drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state ([0046] discloses forcing the control spool back to its original position and opening a drain passage for enabling automatic drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event the associated pilot spool is stuck in an actuated state).
Helbling fails to explicitly state that the valve assembly further comprises a second pilot-operated directional control valve, and the system further comprises a third fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the first direction, a fourth fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the second direction.
Entwistle discloses (Fig. 1) a redundant hydraulic system comprising:
a hydraulic fluid pressure source (15, 21),
a hydraulic fluid reservoir (11),
a hydraulically driven actuator (3) having a first chamber and a second chamber (depicted top and bottom chamber of (3)),
a redundant sectional or monoblock valve assembly (1) having a first pilot-operated directional control valve (5a) and a second pilot-operated directional control valve (5b), each including:
an inlet port (10a) fluidly connected for receiving high-pressure hydraulic fluid from the hydraulic fluid pressure source (Col 3 Ln 60-64),
an outlet port (10b) fluidly connected for draining hydraulic fluid to the hydraulic fluid reservoir (Col 3 Ln 60-64),
a first actuator port (9a) fluidly coupled with the first chamber of the hydraulically driven actuator (Col 3 Ln 60-64),
a second actuator port (9b) fluidly coupled with the second chamber of the hydraulically driven actuator (Col 3 Ln 60-64), and
a pilot operated flow control spool (6) arranged in a spool bore (depicted bore housing (6)) ,
a first fail-safe solenoid-controlled pilot valve (23a) operably connected to the first directional control valve and configured for driving the flow control spool in a first direction (Col 4 Ln 16-26),
a third fail-safe solenoid-controlled pilot valve (23b) operably connected to the second directional control valve and configured for driving the flow control spool in the first direction (Col 4 Ln 16-26), and
redundant pilot pressure fluid supply system (14/20) having a first pilot pressure fluid supply line (14) and a second pilot pressure fluid supply line (20) configured for supplying pilot pressure fluid to the first to third fail-safe solenoid-controlled pilot valves (Col 4 Ln 20-26), wherein
each of the first to third fail-safe solenoid-controlled pilot valves has a drain passage (depicted passage connected to (T) and (32)).
Entwistle further discloses it is beneficial to provide a second pilot-operated directional control valve and associated solenoid-controlled pilot valves for the purpose of “For safety reasons, it is often necessary to provide several steering circuits or at least several steering valves in such steer-by-wire steering systems. If one of the steering valves does not work properly, the other steering valve is activated, so that the vehicle can still be steered” (Col 1 Ln 31-35).
It would have been obvious to one of ordinary skill in the art, at the time the invention was filed, to modify Helbling, by a second pilot-operated directional control valve and associated solenoid-controlled pilot valves, as taught by Entwistle, for safety reasons.
To further clarify the modification, Helbling was modified to duplicate its own pilot operated direction control valve and associated solenoid-controlled pilot valves resulting in a second pilot-operated directional control valve, and the system further comprises a third fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the first direction, a fourth fail-safe solenoid-controlled pilot valve operably connected to the second directional control valve and configured for driving the flow control spool in the second direction. Entwistle is further used to teach the control thereof later claimed.
Helbling further fails to explicitly state that the internal drain passage that is normally closed is configured for opening for drainage of the pilot pressure when the pilot valve is stuck in an actuated state is automatic.
Erikksson discloses (Fig. 1) a fail-safe solenoid-controlled pilot valve (5) operably connected to a first directional control valve (9) and configured for driving the flow control spool in a first direction [0035-0036],
wherein the fail-safe solenoid-controlled pilot valves has an internal drain passage (“internal fluid line of the spool”) that is normally closed and is configured to automatically open for enabling automatic drainage of pilot pressure fluid supplied from a pilot pressure fluid supply system (13) in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state ([0042]).
It would have been obvious to one of ordinary skill in the art, at the time the invention was filed, to modify Helbling, by providing the fail-safe solenoid-controlled pilot valve configured to automatically open to drain the pilot pressure fluid supplied from the pilot pressure fluid supply system, as taught by Erikksson, for the purpose of enabling automatic drainage in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state.
To further clarify the modification, all of the fail-safe solenoid-controlled pilot valves are modified to be configured for automatic drainage.
Regarding claim 18, Helbling discloses (Fig. 1-2) the valve assembly is a sectional valve assembly (Fig. 1 and [0030] indicated that the valve assembly is a ‘directional valve disk such as is used in a hydraulic control block’, one of ordinary skill would understand that each valve assembly may be assembled in individual work sections, or in a monoblock assembly; in the case wherein the valve assemblies being individual work sections fundamentally requires some form of stacking and/or attachment to form the hydraulic control block).
Regarding claim 19, Helbling discloses (Fig. 1-2) the valve assembly is a monoblock valve assembly (Fig. 1 and [0030] indicated that the valve assembly is a ‘directional valve disk such as is used in a hydraulic control block’, one of ordinary skill would understand that each valve assembly may be assembled in individual work sections, or in a monoblock assembly; in the case wherein the valve assemblies being individual work sections fundamentally requires some form of stacking and/or attachment to form the hydraulic control block).
Regarding claim 20, Erikksson discloses (Fig. 1) each of the first to fourth fail-safe solenoid-controlled pilot valves (5) has a drain passage (“internal fluid line of the spool”) that is configured to automatically open a bypass flow channel (“internal fluid line of the spool”) from the redundant pilot pressure fluid supply system to a discharge port for enabling automatic drainage of pilot pressure fluid supplied from the pilot pressure fluid supply system in the event a pilot spool of the associated fail-safe solenoid-controlled pilot valve is stuck in an actuated state [0042].
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MATTHEW WIBLIN whose telephone number is (571)272-9836. The examiner can normally be reached Monday-Friday 8:00 am - 4:00 pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nathaniel Wiehe can be reached at 571-272-8648. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MATTHEW WIBLIN/ Examiner, Art Unit 3745
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