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 Arguments
Applicant’s arguments, see remarks, filed 03/23/2026, with respect to the objections, U.S.C. 112 rejections and U.S.C. 102 rejections have been fully considered and are persuasive, applicant’s amendments to the claims overcomes these issues and therefore these objections and rejections of the office action dated 03/06/2026 has been withdrawn.
Applicant's arguments filed 03/26/2026 pertaining to the U.S.C. 103 rejections have been fully considered but they are not persuasive.
Applicants remarks state that Bruck’s valve PV only blocks fluid flow if it is not actuated. However, the valve PV is a switching valve that contains a non-return valve. The non-return valve itself is the spring loaded ball check valve that is configured to open in the direction of the rod chamber and cannot open in the direction of the proportional pressure control valve P, therefore permanently blocks fluid flow towards the proportional pressure control valve associated with the rod chamber.
See below for updated rejections.
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, 12, 14-18, 29, 31 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bruck et al. (US 2020/0378409), hereinafter ‘Bruck’ in view of Ma et al. (US 10337532), hereinafter ‘Ma’.
Bruck discloses:
11. (Currently Amended) A hydraulic system having a hydraulically actuatable working cylinder which has a cylinder housing with a piston rod unit which is guided in longitudinal movement therein, is actuatable in opposite directions and subdivides the cylinder housing into a piston chamber and a rod chamber, and having two proportional pressure control valves, of which one is associated with the piston chamber and the other is associated with the rod chamber, wherein a connecting line is connected in a fluid-conducting connection between the rod chamber and the proportional pressure control valve associated with the rod chamber,
said connecting line being guided to an inlet side of the proportional pressure control valve for the piston chamber (absent further limitations pertaining to what is required of “an inlet side”, the annotated side of the valve is interpreted to meet this limitation) such that, when the piston rod unit is extended,
wherein a spring-loaded non-return valve is arranged in the fluid-conducting connection between the rod chamber and the proportional pressure control valve associated with the rod chamber in front of a branch point into a further connecting line, said non-return valve opening in the direction of the rod chamber towards the branch point (the "inlet side" can be either side of the valve of DRV because fluid flows into the valve from both directions depending on the operation of the system, see annotated Bruck Fig. 1', all limitations above are either annotated, apparent from the Figures, or discussed), and the non-return valve being configured to permanently block the flow of fluid in the direction of the proportional pressure control valve associated with the rod chamber (the non-return valve is specifically the spring loaded ball check valve portion of PV. The switching valve is interpreted to be a separate feature, therefore by nature of the spring-loaded ball check valve configuration, it opens in the direction towards the rod chamber and cannot open in the direction towards the proportional pressure control valve P, therefore this limitation is still met by the prior art).
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Bruck does not explicitly disclose wherein the fluid displaced from the rod chamber passes into the piston chamber of the cylinder housing. Bruck paragraph [0021] discloses regenerative load operation but does not explicitly disclose how this operate works in terms of the connecting line that includes VG.
However, Ma discloses a hydraulic system with proportional control valves and actuator regeneration similar to Bruck and the present application and therefore constitutes analogous art. Ma discloses a hydraulic system having a hydraulically actuatable working cylinder which has a cylinder (42) housing with a piston rod unit which is guided in longitudinal movement therein, is actuatable in opposite directions and subdivides the cylinder housing into a piston chamber (48) and a rod chamber (50), and having two proportional pressure control valves (122, 124), of which one is associated with the piston chamber and the other is associated with the rod chamber, wherein a connecting line (line including 110) is connected in a fluid-conducting connection between the rod chamber and the proportional pressure control valve associated with the rod chamber, said connecting line being guided to an inlet side of the proportional pressure control valve for the piston chamber (absent further limitations pertaining to the “inlet side”, the side of 122 connected to the piston chamber 48 meets the limitation of “an inlet side” because fluid flows into valve 122 from chamber 48 during some operations) such that, when the piston rod unit is extended, the fluid displaced from the rod chamber passes into the piston chamber of the cylinder housing (fluid in rod chamber 50 flows through valve 110 to piston chamber 48 during an extension regeneration operation). Ma discloses using a regeneration valve (110) to regenerate flow from the rod chamber to the piston chamber and vice versa to reduce pump flow requirements while increasing flow to the actuator (Col. 6 lines 53-65). Ma also discloses other configurations for the regeneration valve 110 may be used (Col. 6 lines 53-65). Ma’s regeneration valve 110 corresponds to the VG section of Bruck as they both are used for fluid regeneration from one chamber of the actuator to the other.
It is obvious to combine prior art elements according to known methods to yield predictable results. See MPEP 2143(A). The MPEP states the prior art must: (1) teach each claimed element (a method or apparatus that will be modified), (2) show that one of ordinary skill in the art could have combined the elements by known methods and that the combination doesn’t change the function of the elements, and (3) show that one of ordinary skill would have recognized that applying the known technique to the base device would yield predictable results. See MPEP 2143(A).
In this case, Bruck teaches all elements except wherein the fluid displaced from the rod chamber passes into the piston chamber of the cylinder housing. Ma teaches wherein the fluid displaced from the rod chamber passes into the piston chamber of the cylinder housing, which has the function of pump flow requirements while increasing flow to the actuator. When combined into Bruck by utilizing the technique of regenerating fluid from one chamber to the other, it maintains its function of reducing pump flow requirements while increasing flow to the actuator by having flow from one chamber supplement the flow into the other chamber of the actuator. One of ordinary skill would expect predictable results because both references pertain to hydraulic systems having a linear actuator controlled by valves that function in the same manner in the environment of regenerating hydraulic fluid energy from the chambers of the hydraulic linear actuator.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the system of Bruck in view of Ma because all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art.
The combination of Bruck and Ma further render obvious:
12. (Previously Presented) The hydraulic system of claim 11, wherein the proportional pressure control valves can be actuated electromagnetically and connect a return line with an inlet in their non-actuated original position (Bruck, DRV are electromagnetically actuated via solenoids and are able to be connected to the return line T when the solenoids are not actuated and pilot pressure acts on the valves DRV to connect an inlet to the tank line T).
14. (Currently Amended) The hydraulic system of claim 11, wherein, in order to insert the piston rod unit into the cylinder housing of the working cylinder, the proportional pressure control valve belonging to the rod chamber passes into an actuated position in which fluid at a predefinable pressure passes into the rod chamber, while simultaneously displacing fluid from the piston chamber via the non-actuated proportional pressure control valve associated therewith in the direction of the return line to the storage tank (Bruck paragraph [0017], [0020], [0021] renders obvious having the piston side DRV opened to discharge fluid during an actuator retraction operation since the fluid must return to the tank through the valves normally during a non-excessive pressure state meaning the DBV valves are not opened).
15. (Previously Presented) The hydraulic system of claim 11, wherein the respective proportional pressure control valve is configured to be identical to the other proportional pressure control valve (Bruck DRV valves associated with the piston and rod side are identical, see Fig. 1).
16. (Currently Amended) The hydraulic system of claim 11, wherein a further inlet of both proportional pressure control valves is connected to the return line, said further inlet being connected at least in a fluid direction to the piston chamber when the respective proportional pressure control valve is in the non-actuated original position (Bruck when utility port "A" is pressurized, both DRV valves are connected with corresponding inlets to the return line T).
17. (Currently Amended) The hydraulic system of claim 11, wherein an outlet of the proportional pressure control valve belonging to the rod chamber is connected for at least some of the time to the further inlet of the proportional pressure control valve belonging to the piston chamber via the connecting line (absent further limitations as to what would be considered the “outlet”, any port that allows fluid out of the proportional pressure control valve can be an outlet, and thus an outlet of DRV associated with the rod chamber is connected to an inlet of the DRV associated with the piston chamber via the connecting line that includes VG).
18. (Currently Amended) The hydraulic system of claim 11, wherein a further inlet of the proportional pressure control valve belonging to the rod chamber is connected to a pressure supply line (supply line P is connected to an inlet of both DRV as seen in Fig. 1).
29. (Previously Presented) The hydraulic system of claim 12, wherein the return line leads to a storage tank (tank connected to "T", paragraph [0018]).
31. (Previously Presented) The hydraulic system of claim 11, wherein the non-return valve is spring loaded (PV includes spring loaded non-return valve).
Allowable Subject Matter
New claims 32 and 33 are allowed.
Claims 13 and 30 are 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 disclose nor render obvious a hydraulic system wherein, in order to extend the piston rod unit from the cylinder housing, the proportional pressure control valve belonging to the rod chamber passes into an actuated position in which fluid at a predefinable pressure passes via the connecting line and via the proportional pressure control valve associated with the piston chamber, which is in a similarly actuated position, into the piston chamber as claimed in claim 13, in combination with its base claim limitations.
Claim 30 is allowable because it depends from allowable claim 13.
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 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 April 22, 2026
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