Prosecution Insights
Last updated: April 19, 2026
Application No. 17/387,291

INTEGRATED BLENDER AND FRICTION REDUCER SYSTEM

Final Rejection §103
Filed
Jul 28, 2021
Examiner
MCCARTY, PATRICK M
Art Unit
1774
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Stewart & Stevenson LLC
OA Round
6 (Final)
60%
Grant Probability
Moderate
7-8
OA Rounds
3y 5m
To Grant
84%
With Interview

Examiner Intelligence

Grants 60% of resolved cases
60%
Career Allow Rate
77 granted / 129 resolved
-5.3% vs TC avg
Strong +25% interview lift
Without
With
+24.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
47 currently pending
Career history
176
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
49.7%
+9.7% vs TC avg
§102
14.9%
-25.1% vs TC avg
§112
32.0%
-8.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 129 resolved cases

Office Action

§103
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 Response to Arguments The objection to claim 22 is withdrawn. The rejection of claims 18-21 under 35 U.S.C. 112(b) is withdrawn. Applicant’s arguments with respect to claims 1-7, 10-22 and 24-27 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 Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claims 1-2, 4-5, 10-11, 15, 17-19, 21 and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757). Regarding claim 1, Douthitt et al. discloses an integrated blender (abstract) system comprising: A skid (title, chassis 10, load frame portion 11, Fig. 1); the skid positioned horizontally relative to a surface upon which it rests as shown below: PNG media_image1.png 355 700 media_image1.png Greyscale Douthitt et al. discloses a blender assembly, the blender assembly mounted on the skid (blender assembly comprising mixing means 30, pumps, and piping shown mounted to the skid comprising chassis 10, load frame portion 11, etc. Fig. 1), the blender assembly including: A blender tub (mixing means 30 with mixing tub 31), the blender tub including an outlet (fluids are removed through an outlet connected to tub pipe 72, col. 7, lines 62-65); A supply pipe (manifold 64 has pipe sections meeting the limitation of “supply pipe”, Fig. 2, col. 7, lines 45-46), the supply pipe coupled between a suction pump (transfer pump 60) and the blender tub (pump 60 draws from inlet manifold 61 and pumps to the mixing means 30/tub 31, col. 4, lines 6-7, col. 4, lines 13-15); An outlet pipe (tub pipe 72, col. 7, lines 62-65) coupled to the outlet of the blender tub; A dry product additive system (dry chemical additive means 50) including: A hopper (hopper means 51), an eductor assembly (eductor means 52), the eductor assembly including a suction inlet (connected with hopper 51, Fig. 5), a motive inlet (“flow through line 53 to eductor means 52”, col. 6, line 49, Fig. 4), and an outlet (an outlet structure must be present to feed the discharge of the eductor to the tub 31, col. 3, lines 58-63), the outlet positioned to eject fluid and product into the blender tub (the eductor feeds the tub from above, col. 3, lines 58-63). Insomuch as Douthitt et al. does not disclose that the outlet is also a nozzle, Markfelt et al. teaches a mixing device having an eductor assembly (Fig. 2) with a suction inlet, a motive inlet, and an outlet nozzle (expansion nozzle 80, col. 4, lines 7-9) as shown below: PNG media_image2.png 339 734 media_image2.png Greyscale Therefore, 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 teachings of Douthitt et al. wherein the eductor assembly has an outlet nozzle (Markfelt et al., Fig. 2, col. 4, lines 7-9), the outlet nozzle positioned to eject fluid and product into the blender tub (Douthitt et al., the eductor feeds the tub from above, col. 3, lines 58-63). The person of ordinary skill in the art would have found it obvious to use a conventional eductor as the eductor of Douthitt et al. in order to achieve the predictable result of providing an eductor means for mixing (Douthitt et al., eductor means 52). See KSR International Co. v. Teleflex Inc. (KSR), 550 U.S. 398, 82 USPQ2d 1385 (2007). Furthermore, Markfelt et al. discloses a second outlet nozzle (exit nozzle portion 60) downstream of the first eductor outlet nozzle shown above (Fig. 1) as shown below: PNG media_image3.png 380 781 media_image3.png Greyscale Therefore, it would have also been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the teachings of Douthitt et al. by including a second outlet nozzle as part of the eductor assembly. The person of ordinary skill in the art would have found it obvious to use a second outlet nozzle in order to increase the speed of the fluid mixture entering the blender tub and thereby also improve mixing (Markfelt et al., lines 33-35). Douthitt et al. does not disclose a pickup funnel nor does Douthitt et al. expressly disclose a feeder system. However, Saffioti teaches a dry product additive system (using guar powder, abstract) comprising an eductor (col. 2, lines 16) and a hopper (powder hopper 1) and further teaches a pickup funnel (col. 2, line 13) and a feeder system (comprising dispenser 2) configured to transport product from the hopper to the pickup funnel (Fig. 1). Therefore, 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 teachings of Douthitt et al. to further include a feeder system, the feeder system configured to transport product from the hopper to a pickup funnel (Saffioti, via pneumatic conveyance hose 5) whereby the eductor assembly’s suction inlet is coupled to the pickup funnel by a suction hose (Saffioti, hose 5). The person of ordinary skill in the art would have been motivated to include a feeder system and pickup funnel in order to facilitate feeding the eductor. Douthitt et al. does not teach a dedicated supply pump for the eductor. However, Saffioti teaches a centrifugal pump (pump 11) dedicated for the eductor and Parr et al. teaches a blending system (mixing hydraulic fluid, para. [0001]) having an eductor (eductor 20), outlet nozzles (eductor nozzles 265), a dedicated supply pump for an eductor (second pump 90) and a suction pump for feeding (first pump 70). Therefore, 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 teachings of Douthitt et al. to further add a supply pump to provide the motive fluid to the eductor where the motive inlet is coupled to the supply pump by a motive fluid hose. The person of ordinary skill in the art would have been motivated to add a supply pump in order to provide redundant pump means when one pump needs maintenance or is otherwise offline (Parr et al., paragraph 62). Insomuch as Douthitt et al. does not disclose the dry product additive system is positioned on the skid, Trahan et al. discloses an integrated blender system comprising a skid (para. [0004]) positioned horizontally with the ground (Fig. 6) and including a blender assembly (hydration tank 222) and a dry product additive system (comprising components shown in Fig. 3, contents of powder bin 222/112 is fed via feeder 120 to conduit 122, Fig. 3, leading to eductor, Fig. 5A or 5B, para. [0030]-[0031]) and Trahan teaches the dry product additive system is positioned on the skid (Fig. 6) as shown below: PNG media_image4.png 544 880 media_image4.png Greyscale Therefore, 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 teachings of Douthitt et al. by positioning the dry product additive system on the skid. The person of ordinary skill in the art would have found it obvious to rearrange parts of the integrated blender system wherein the dry product additive system is positioned on the skid as an obvious matter of design choice for an integrated blender system which would still function to provide dry products to the blender. See In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) and In re Kuhle, 526 F.2d 553, 188 USPQ 7 (CCPA 1975). Douthitt et al. does not expressly teach that the hopper further comprises an upper hatch. However, Saffioti teaches that the hopper (hopper 1) further comprises an upper hatch (col. 5, line 66 – col. 6, line 1). Therefore, 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 teachings of Douthitt et al. to further include an upper hatch on the hopper. The person of ordinary skill would have found it obvious to include an upper hatch in order to add material to the hopper from above. Presumably Douthitt’s hopper is operated at atmospheric pressure. Otherwise, Luharuka et al. discloses a blender system (para. [0024]) and further teaches hoppers (compartments 140) having an upper hatch (hatch 146) which are configured to be operated at atmospheric pressure (vacuum breaker used to equalize pressure between the atmosphere and the hopper/compartment, para. [0026]). Therefore, 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 teachings of Douthitt et al. wherein the hopper is adapted to be operated at atmospheric pressure. The person of ordinary skill in the art would have been motivated to adapt the hopper for operation at atmospheric pressure in order to prevent suction from developing with in the hopper (Luhatuka et al., para. [0026]) which would interfere with operation of the hopper or to prevent pressure build up from within the hopper which could result in excess dust generation. Douthitt et al. does not disclose a hopper fill tube. However, Terry et al. discloses a hopper (tank 101) for use in a blender system (para. [0002]) and Terry et al. further teaches that the hopper is configured to be loaded with hatch (hatch 107) closed (as the hopper may be loaded via funnel 108 which is located on the hatch, Fig. 1) and insomuch as Terry et al. does not teach the funnel is a tube, Stefanelli et al. teaches a similar hopper (hopper 20) for granular or powdery materials (abstract) having a fill tube (fill chute 86) similar to Terry’s funnel (Terry et al., funnel 108) which extends a short distance (Fig. 1) from the hopper lid (and therefore also the hopper which comprises the lid) and which is adapted to fill the hopper when the hopper hatch (lid 42) is closed, in that the fill tube is in the lid (Fig. 1, para. [0036]). It is also noted that Terry et al. teaches a fill tube (hose connection 114, Fig. 1) extending a short distance from the hopper (tank 101, Fig. 1) and Terry teaches that the hopper may be filled via the tube by gravity feed (para. [0030]) or pneumatically (para. [0036]). Therefore, 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 teachings of Douthitt et al. wherein the blender and dry product additive system includes a hopper fill tube (Stefanelli et al., chute 86), the hopper fill tube coupled to the hopper and extending a short distance therefrom (Stefanelli et al., Fig. 1); wherein the hopper fill tube provides a passage for material to enter the hopper; wherein the hopper fill tube is adapted to fill the hopper when the upper hatch is closed (Stefanelli et al., Fig. 1, lid 42 must be closed when filling using the chute 86, Terry et al., hatch 107 must be closed when filling using a funnel 108, Fig. 1). The person of ordinary skill in the art would have been motivated to use a hopper fill tube positioned in the upper hatch in order to assist with filling the hopper manually such as by providing a smaller opening to prevent excessive dust from escaping during loading. Douthitt et al. does not disclose a water tank in fluid connection with the supply pump. However, Saffioti who teaches a supply pump (supply pump 11) as discussed above, further teaches the supply pump receives fresh water from a fresh water chamber (Fig. 1). Assuming, arguendo, Saffioti’s chamber does not constitute a separate tank, Otte discloses a chemical mixing device (abstract) which may be used for mixing dry products (col. 1, lines 46-48) and which is mounted on a skid (trailer frame 14) and which further comprises a water tank (drum 20, col. 2, lines 36-37) which is also mounted on the skid (trailer 14, Fig. 1) and in communication with a supply pump (pump 28). Therefore, 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 teachings of Douthitt et al. wherein the blender system/dry product additive system further includes a water tank in fluid communication with the supply pump. The person of ordinary skill would have found it obvious to use a water tank to provide a source of water for the blending system. Douthitt does not disclose the skid is part of a rockover trailer. However, Stegemoeller discloses a system which is analogous art at least because it is reasonably pertinent to the problem of transporting systems to well sites (para. [0001]) including those accessed by unimproved roads (para. [0002]) and Stegemoeller discloses wherein a skid (platform 100) is part of a rockover trailer adapted to place a bottom of the skid onto contact with the surface such that at least one wheel used to roll in towing of the rockover trailer is raised out of contact with the surface (para. [0037]) and hence unloaded from weight on the skid (Fig. 3) as shown below: PNG media_image5.png 270 689 media_image5.png Greyscale Therefore, 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 teachings of Douthitt et al. wherein the skid is part of a rockover trailer adapted to place a bottom of the skid onto contact with the surface such that at least one wheel used to roll in towing of the rockover trailer is raised out of contact with the surface and hence unloaded from weight on the skid. The person of ordinary skill would have been motivated to use a rockover trailer for transporting on unimproved surfaces (Stegemoeller, para. [0002]) such as over rocks and bumps (Stegemoeller, para. [0042]) and to improve stability of equipment during use (Stegemoeller, para. [0037]). Regarding claim 2, Douthitt et al. discloses a tub paddle motor (hydraulic motor means 33 could also power a shaft with paddles) to power the agitator, but does not expressly teach blender paddles. However, Douthitt et al. teaches that any suitable mixing means may be used (col. 3, lines 25- 26) and Parr et al. teaches a mixing tank (hydration tank 60) may utilize high shear paddles (para. [0080]). Therefore, 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 teachings of Douthitt et al. by substituting the screw agitator for blender paddles wherein the blender further comprises one or more blender paddles positioned within the blender tub, the blender paddles driven by a tub paddle motor. To one of ordinary skill in the art before the effective filing date of the claimed invention it would have been obvious to substitute one agitator type for another which provides the predictable result of facilitating mixing in the blender tub. See KSR International Co. v. Teleflex Inc. (KSR), supra. Regarding claim 4, Douthitt et al. teaches the suction pump (pump 60) is positioned to draw fluid from a suction manifold (inlet manifold 61, col. 4, lines 12-13). Regarding claim 5, Douthitt et al. does not expressly disclose a flow meter positioned on the supply pipe. However, Parr et al. teaches a supply line (inflow line 50, Fig. 1 and Fig. 2) between the suction pump (pump 70) and the tub (hydration tank 60). Parr et al. further teaches a flow meter (metering device 80, Fig. 1) on the supply line. Therefore, 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 teachings of Douthitt et al. to further include a flow meter on the supply line. The person of ordinary skill would have found it obvious to meter the supply line in order to control the concentration of the fluids being mixed. Regarding claim 10, Douthitt et al. does not teach that the feeder system comprises a trough. However, Saffioti teaches a feeder system comprising a trough (housing for dispenser 2), the trough positioned below the hopper such that product positioned within the hopper is gravity fed (it is located above the trough and its movement into the trough will be assisted by gravity) into the trough, where the trough is coupled to the pickup funnel (receives feed from the trough/feed auger) as shown below: PNG media_image6.png 465 779 media_image6.png Greyscale Therefore, 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 teachings of Douthitt et al. to further include wherein the feeder system comprises a trough, the trough positioned below the hopper such that product positioned within the hopper is gravity fed into the trough with the trough coupled to the pickup funnel. The person of ordinary skill in the art would have been motivated to include the feeder system of Saffioti in order to facilitate the transfer of solid materials into the eductor and blending tub. Regarding claim 11, Douthitt et al. does not teach a feeder system comprising a feed auger positioned within a trough. However, Saffrioti discloses a feeder system comprising a feed auger, the feed auger positioned within the trough (Saffrioti, col. 5, line 46, Fig. 1 and annotated above). Therefore, 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 teachings of Douthitt et al. to further include wherein the feeder system comprises a feed auger, the feed auger positioned within the trough. The person of ordinary skill in the art would have been motivated to include the feeder system of Saffioti in order to facilitate the transfer of solid materials into the eductor and blending tub. Regarding claim 15, Douthitt et al. does not teach a supply pump. However, as discussed for claim 1, Saffrioti teaches a supply pump (pump 11) for the eductor and further teaches that it is a centrifugal pump (pump 11, col. 4, lines 15-18). Therefore, 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 teachings of Douthitt et al. wherein the supply pump is a centrifugal pump. The person of ordinary skill would have found it obvious to use a known pump type for supplying motive fluid to an eductor. Regarding claim 17, Douthitt et al. does not disclose a vacuum breaker valve. However, Saffrioti et al. teaches a vacuum breaker valve (vacuum interrupter valve 8) positioned on the eductor assembly (Fig. 1) and wherein the vacuum breaker valve is fluidly coupled to the suction inlet (col. 2, lines 20-22, Fig. 1). Therefore, 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 teachings of Douthitt et al. to further include a vacuum breaker valve positioned on the eductor assembly fluidly coupled to the suction inlet. The person of ordinary skill would have been motivated to include a vacuum breaker valve in order to facilitate transferring powder in the suction hose (Saffrioti, col. 6, lines 42-43). Regarding claim 18, Douthitt et al. discloses a discharge pump (booster pump means 70) coupled to the outlet (an outlet for the tub must be present which is connected to outlet pipe/blender tub pipe 72, col. 7, lines 62-65) as shown below: PNG media_image7.png 417 718 media_image7.png Greyscale Regarding claim 19, Douthitt et al. discloses the discharge pump (pump 70) is coupled to a discharge manifold (discharge manifold 76, col. 4, lines 46-49) by an discharge pipe (manifold 76 comprises pipe sections meeting the limitation of “discharge pipe”, Fig, 4, shown above). Regarding claim 21, Douthitt et al. discloses the outlet pipe comprises a valve (valve means 73, col. 4, line 42). Regarding claim 27, Douthitt et al. discloses a liquid chemical additive system (liquid chemical additive supply means 90, col. 5, lines 29-30) that includes a liquid chemical pump (hydraulic pump means 92, col. 5, line 29) fluidly connected to the blender tub (outlets may be connected to the blender tub, col. 5, lines 33-34). Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 2 above and in further view of Whitlatch (US 20200290000). Regarding claim 3, the above cited references for claim 2 do not expressly disclose that the tub paddle motor is coupled to the blender paddles by a paddle gearbox. However, Whitlatch teaches a “tub” (mixing vessel 2) for mixing a variety of well materials (para. [0002]) and Whitlatch further teaches the mixing vessel has paddle agitators where the electric motor is coupled to the paddles by a paddle gearbox (“gear driven”, para. [0031]). Therefore, 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 teachings of Douthitt et al. by substituting the hydraulic motor for an electric tub paddle motor coupled to the blender paddles by a paddle gearbox. The person of ordinary skill would have found it obvious to substitute one motor type for another known type and achieve the predictable result of powering an agitator. The person of ordinary skill would have been motivated to include a gearbox in order to facilitate mixing of different components (having different mixing characteristics, density, viscosity, etc.). Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Green et al. (US 20150360188). Regarding claim 6, Douthitt et al. discloses a proppant adding system (hopper means 41, gate valve 43, etc. col. 1, line 33, col. 3, lines 47 – 54) and insomuch as Douthitt et al. does not disclose the proppant feed system is positioned on the skid, Green et al. teaches a blender system (para. [0016]) comprising a skid (mobile platform 401) and further teaches that the blender system comprises a proppant feed system (para. [0047]) wherein the proppant feed system is positioned on the skid (Fig. 4) as shown below: PNG media_image8.png 580 817 media_image8.png Greyscale Therefore, 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 teachings of Douthitt et al. to include a proppant feed system wherein the proppant feed system is positioned on the skid. The person of ordinary skill in the art would have found it obvious to use a proppant feed system for use on skid for producing fracturing fluid (Douthitt et al., col. 1, lines 25-29). Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417), Stegemoeller et al. (US 20160237757) and Green et al. (US 20150360188) as applied to claim 6 above and in further view of Christinzio et al. (US 20210198994). Regarding claim 7, Douthitt et al. discloses the proppant feed system comprises a proppant hopper (hopper means 41) and teaches using a screw type conveyor to add proppant to the blender tub (col. 1, lines 33 – 35), but does not expressly disclose an auger connected to the bottom of the proppant hopper and extending to a position above the blender tub nor does Douthitt et al. expressly disclose an auger motor positioned to drive the auger and insomuch as Douthitt et al. does not explicitly teach the proppant hopper is positioned at the end of the skid, Christinzio et al. teaches a blender (abstract) which may be located on a mobile unit (Fig. 1, para. [0020]) and Christinzio et al. further teaches a proppant hopper (110, Fig. 1 or 402, Fig. 4A) with an auger (auger 108, Fig. 1 or auger 404, Fig. 4A) for feeding the blending unit (unit 106, Fig. 1 or tub 408, Fig. 4A) where the auger is connected to the bottom of the proppant hopper and extends to a position above the blender tub (Fig. 4A) and an auger motor (motor 406, Fig. 4A) is positioned to drive the auger (Fig. 4A) and Green et al. teaches a proppant hopper (tank 406, para. [0047]) and further teaches the proppant hopper is positioned at the end of the skid (Fig. 4). Therefore, 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 teachings of Douthitt et al. to include an auger connected to the bottom of the proppant hopper and extending to a position above the blender tub and an auger motor (Christinzio et al., motor 406) positioned to drive the auger wherein the proppant hopper (Green et al., tank 406) is positioned at an end of the skid (Green et al., Fig. 4). The person of ordinary skill would have found it obvious to add these components as a known means to feed proppant to a blending tub and to position the proppant hopper at the end of the skid as a known location for a hopper (Douthitt et al., Hopper 41, Fig. 5, Green et al., tank 406, Fig. 4) which would facilitate loading of the hopper using separate equipment. Assuming, arguendo, that Douthitt et al. did not teach that hopper 41 is a “proppant hopper”, Douthitt et al. states that the disclosure is in reference to fracturing (col. 9, lines 42-44) and that propping agents prevent geological formations from closing after the fracturing thereof and are mixed as components of the fracturing fluid (col. 1, lines 22-29) and Christinzio et al. further teaches a proppant hopper (110, Fig. 1 or 402, Fig. 4A) as does Green et al. (tank 406). Therefore, 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 teachings of Douthitt et al. by including a proppant hopper. The person of ordinary skill would have been motivated to include a proppant hopper in order to feed proppants for mixing a fracturing fluid. Claims 12, 16, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1, 11, or 19 above and in further view of Yeung (US 20190009232). Regarding claim 12, insomuch as the above cited references for claim 11 do not explicitly disclose the feed auger is driven by a motor, Yeung teaches a blender where augers are connected to motor controllers (and therefore indicating the presence of a motor, para. [0094]). Therefore, 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 teachings of the above cited references for claim 11 to further include wherein the feed auger is driven by a feeder motor. The person of ordinary skill in the art would have found it obvious to use a motor as a known means to supply power to an auger. Regarding claim 16, insomuch as the above cited references for claim 1 do not explicitly disclose the supply pump is driven by a pump motor, Yeung teaches a blender where centrifugal pumps are connected to motor controllers (and therefore indicating the presence of a motor, para. [0089]). Therefore, 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 teachings of the above cited references for claim 1 to further include wherein the supply pump is driven by a pump motor. The person of ordinary skill in the art would have found it obvious to use a motor as a known means to supply power to a pump. Regarding claim 20, Douthitt et al. does not expressly disclose a flow meter or densitometer on the outlet pipe or discharge pipe. However, Yeung teaches a flow meter in the discharge line of a blender to measure the flow rate from the discharge pump (para. [0128]). Therefore, 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 teachings of Douthitt et al. wherein the discharge pipe further comprises a flow meter. The person of ordinary skill in the art would have been motivated to include a flow meter in order to control the speed of the discharge pump (Yeung, para. [0128]). Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Allen (US 20040218463) and Katzer et al. (US 3338560). Regarding claim 13, the above cited references for claim 1 do not expressly teach that the pickup funnel comprises a vent. However, Allen teaches a dry product additive system (comprising dry gel powder supply tank 42 – a hopper, para. [0028]) and further discloses a pickup funnel which is vented (Fig. 1) in that it receives a fluid stream to carry material as shown below: PNG media_image9.png 546 663 media_image9.png Greyscale Insomuch as Allen does not expressly disclose the source of fluid, Katzer et al. teaches a mixing apparatus for dispersing solids in liquids (col. 1, lines 8-9) where a vent (end 56, Fig. 1) is used for introducing outside air from the atmosphere in order to carry the solids. Therefore, 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 teachings of Douthitt et al. to further include wherein the pickup funnel comprises a vent. The person of ordinary skill in the art would have been motivated to include a vent in order to facilitate picking up powder for transfer through the suction hose and to maintain enough velocity pressure in the hose to keep the powder flowing. Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Case et al. (US RE46725E). Regarding claim 14, Douthitt et al. does not disclose a load cell positioned between the hopper and the skid. However, Saffrioti teaches a load cell under one side of the hopper (col. 7, line 11-12) Therefore, 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 teachings of Douthitt et al. wherein the hopper includes a load cell. The person of ordinary skill in the art would have been motivated to use a load cell in order to weigh the contents of the hopper. Insomuch as the above-cited references do not expressly disclose the load cell is positioned between the hopper and hopper support struts; Case et al. teaches an oilfield blending apparatus (abstract) where load cells (load sensors 212, 316, 418, Fig. 2-4) are positioned between the hopper and hopper support struts (Fig. 3 and Fig. 4). Therefore, 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 teachings of Douthitt et al. wherein the load cell is positioned between the hopper and hopper support struts. The person of ordinary skill in the art would have found it obvious to use a known configuration for arranging load cells in order to achieve the predictable result of weighing the contents of a hopper. See In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) and In re Kuhle, 526 F.2d 553, 188 USPQ 7 (CCPA 1975). Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Han et al. (US 10864487). Regarding claim 22, the above cited references for claim 1 do not expressly teach an air compressor connected to actuate components of the integrated blender. However, Han et al. teaches mobile mixing equipment (abstract) and further teaches an air compressor (col. 4, lines 9-10) connected to actuate components of the integrated blender (valves, col. 4, line 7). Therefore, 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 teachings of Douthitt et al. to include an air compressor and utilize the compressor with pneumatic valves (components of an integrated blender). The person of ordinary skill in the art would have been motivated to include an air compressor in order to operate pneumatic equipment (Han et al., col. 4, line 10) such as components of a pneumatically filled hopper as taught by Saffrioti (col. 6, lines 1-2 ) which would mitigate dust generation and commonly used pneumatic valves (Han, col. 4, lines 8-9 ). To one of ordinary skill in the art before the effective filing date of the claimed invention it would have been obvious to substitute one valve type (unknown valves type of Douthitt et al.) for a commonly used type (Han, col. 4, lines 8-9, pneumatic valve) powered by a compressor and thereby providing the predictable result of controlling flows. See KSR International Co. v. Teleflex Inc. (KSR), supra. Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Noles (US 20120127822). Regarding claim 24, Douthitt et al. discloses a liquid chemical additive system (liquid chemical additive supply means 90, col. 5, lines 29-30) the liquid chemical additive system including a liquid chemical pump (hydraulic pump means 92, col. 5, line 29) and insomuch as Douthitt et al. does not teach that the liquid chemical additive system is positioned on the skid, Noles teaches a blender system (abstract) which includes a liquid chemical additive system having a pump (pump 61, para. [0025]) and liquid chemical containers (sources 43, Fig. 6) and Noles further teaches the liquid chemical additive system is positioned on a skid (trailer 60, Fig. 6). Therefore, 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 teachings of Douthitt et al. wherein the liquid chemical additive system is positioned on the skid. The person of ordinary skill in the art would have found it obvious to arrange the liquid chemical additive system on the skid as an obvious matter of design choice and by doing so the liquid chemical additive system would still function to feed chemicals to the blender. See In re Japikse, supra and In re Kuhle, supra. Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Zhong et al. (US 20210308638), Curry et al. (US 20210131410), and Hinderliter (US 20190383123). Regarding claim 25, Douthitt et al. does not teach a transformer. However, Zhong et al. teaches a mobile fracturing fluid mixer (abstract, Fig. 2) and further discloses a transformer (para. [0081]) and Curry et al. likewise teaches a mobile system for fracturing (para. [0002]) and further teaches a transformer for utilizing external power sources (para. [0094]). Therefore, 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 teachings of Douthitt et al. to further include a transformer positioned on the skid and connected to supply electric power of an appropriate voltage to systems of the integrated blender system such as to provide an alternate source of electricity to power electrical components on the skid (Douthitt et al., such as an electrical meter, col. 5, line 54, electrical power for agitators, col. 3 line 40 ). The person of ordinary skill in the art would have been motivated to include a transformer in order to facilitate the use of different sources of electricity (Curry et al., para. [0094]) for the skid in order to power electrical components (such as an electrical meter, col. 5, line 54, electrical power for agitators, col. 3 line 40). Further, Hinderliter teaches a fracturing system (abstract) which utilizes a generator (generator 50) to generate electricity and the generator may include a transformer (transformer 56) in order to step down the voltage for powering equipment including mixing equipment (chemical pumps, proppant source, blender unit, etc., para. [0033]). Therefore, 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 teachings of Douthitt et al. by including a generator with a transformer. The person of ordinary skill in the art would have found it obvious to use a known source of electricity for use with fracturing equipment, such as a generator with a transformer, to achieve predictable result of supplying electrical power to electrical equipment. Claim 26 is rejected under 35 U.S.C. 103 as being unpatentable over Douthitt et al. (US 4311395) in view of Saffioti (US 10994445), Parr et al. (WO 2015076786), Markfelt et al. (US 3881656), Trahan et al. (US 20200129934), Terry et al. (US 20170158426), Stefanelli et al. (US 20170088371), Luharuka et al. (US 20130309052), Otte (US 5609417) and Stegemoeller et al. (US 20160237757) as applied to claim 1 above and in further view of Christinzio et al. (US 20210198994). Regarding claim 26, Douthitt et al. does not disclose a variable frequency drive positioned on the skid. However, Christinzio et al. teaches a blender with a variable frequency drive (abstract). Therefore, 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 teachings of Douthitt et al. to further include a variable frequency drive positioned on the skid. The person of ordinary skill in the art would have been motivated to include a variable frequency drive in order to provide real-time control of electric motors (para. [0005]). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Woolslayer et al. (US 3083987) discloses a trailer skid for hauling oilfield equipment where at least one wheel is raised out of contact with the surface as shown below: PNG media_image10.png 257 1012 media_image10.png Greyscale Wiemers et al. (US 20180297880) discloses a mobile liquid treatment station platform trailer where at least one wheel is raised out of contact with the surface (Fig. 2) as shown below: PNG media_image11.png 346 1191 media_image11.png Greyscale Stegemoeller et al. (US 20190009230) discloses a fluid management system for a well site wherein the system may be positioned on a platform trailer (para. [0029]) where at least one wheel is raised out of contact with the surface (Fig. 2 or Fig. 3) as shown below: PNG media_image12.png 270 1054 media_image12.png Greyscale Reddy et al. (US 20180030788) discloses a rockover trailer for transporting oil and gas equipment. Teichrob et al. (US 20120099954) discloses a rockover trailer for transporting oil and gas equipment. 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 PATRICK M MCCARTY whose telephone number is (571)272-4398. The examiner can normally be reached Monday - Thursday 9:00 AM - 5:00 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Claire Wang can be reached at 571-270-1051. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /P.M.M./Examiner, Art Unit 1774 /CLAIRE X WANG/Supervisory Patent Examiner, Art Unit 1774
Read full office action

Prosecution Timeline

Jul 28, 2021
Application Filed
Jun 27, 2023
Non-Final Rejection — §103
Oct 04, 2023
Response Filed
Nov 13, 2023
Final Rejection — §103
Feb 12, 2024
Response after Non-Final Action
Apr 19, 2024
Response after Non-Final Action
Apr 19, 2024
Request for Continued Examination
Apr 22, 2024
Response after Non-Final Action
May 13, 2024
Non-Final Rejection — §103
Aug 20, 2024
Response Filed
Oct 30, 2024
Final Rejection — §103
Feb 06, 2025
Request for Continued Examination
Feb 10, 2025
Response after Non-Final Action
May 19, 2025
Non-Final Rejection — §103
Aug 01, 2025
Interview Requested
Aug 11, 2025
Applicant Interview (Telephonic)
Aug 11, 2025
Examiner Interview Summary
Aug 28, 2025
Response Filed
Nov 06, 2025
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12600541
BLEND THROUGH CUP LID
2y 5m to grant Granted Apr 14, 2026
Patent 12593855
DRINK MAKER WITH DETACHABLY CONNECTABLE MIXING VESSEL
2y 5m to grant Granted Apr 07, 2026
Patent 12589365
SOLUTION PREPARATION DEVICE, AND SOLUTION REPLACEMENT SYSTEM AND METHOD
2y 5m to grant Granted Mar 31, 2026
Patent 12588609
PLANT NUTRIENT PREPARATION AND DELIVERY SYSTEM
2y 5m to grant Granted Mar 31, 2026
Patent 12582126
AUTOMATED FOOD ARTICLE MAKING SYSTEM AND METHOD
2y 5m to grant Granted Mar 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

7-8
Expected OA Rounds
60%
Grant Probability
84%
With Interview (+24.8%)
3y 5m
Median Time to Grant
High
PTA Risk
Based on 129 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month