US 11967921

US Patent 11967921 Summary

• Title: Self-powered solar tracker apparatus
• Assignee: Nextpower LLC (current assignee)
• Inventors: Yang Liu, Alexander W. Au
• Filing Date: August 9, 2022
• Issue Date: April 23, 2024
• Abstract: A solar tracker apparatus includes an adjustable hanger assembly that has a clam shell hanger assembly. The clam shell hanger assembly may hold a torque tube comprising a plurality of torque tubes configured together in a continuous length from a first end to a second end. A center of mass of the solar tracker apparatus may be aligned with a center of rotation of the torque tubes, in order to reduce a load of a drive device operably coupled to the torque tube. Solar modules may be coupled to the torque tubes. The solar tracker includes an energy system that includes solar panel, a DC to DC converter, a battery, and a micro-controller. The energy system may facilitate full operation movement of the tracker apparatus without any external power lines.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: This claim describes a self-powered solar tracker apparatus. It includes a frame assembly that holds multiple solar modules. A drive device is connected to the frame assembly, allowing it to move. The key feature is an energy system that powers this drive device. This energy system includes a solar panel, a DC-to-DC converter, a battery, a boost converter, and a capacitor. The solar panel is rated at less than 300 Watts. The capacitor ensures a stable voltage for the drive, and a microcontroller manages the power components. The entire system is designed to operate the tracker with less than 15 Watt-hours per day without needing an external power source.
• Independent Claim 13: This claim describes a method for assembling a solar tracker apparatus. The method involves several steps:
  1. Installing a clamp housing member in an upright position on a pier structure. This housing member has a spherical bearing.
  2. Attaching a clam shell clamp to this spherical bearing, so it hangs from it.
  3. Supporting a torque tube between the two halves of the clam shell clamp. This torque tube is positioned off-center from its rotation point.
  4. Coupling a pin to connect the clam shell clamp halves and the spherical bearing.
  5. Coupling a first and second half of the clam shell clamp to "sandwich" the spherical bearing to a "tongue region" of the clamp housing member.
• Independent Claim 14: This claim focuses on a solar tracker apparatus that includes a clamp housing member in an upright direction, with a lower region coupled to a pier and an upper region having a spherical bearing device. A clam shell clamp is coupled to and suspended from this spherical bearing. A torque tube, with a first and second end, is coupled to the spherical bearing device at its first end, supporting it from the upper region of the clamp housing member. This torque tube is offset from its center of rotation. A drive device is coupled to the second end of the torque tube, and the design ensures that the drive device and torque tube are largely free from twisting under load.
• Independent Claim 15: This claim describes a solar tracker apparatus with a drive device connected to a crank, which is offset from a continuous torque tube made of multiple cylindrical torque tubes. This continuous torque tube has a frame assembly attached to it, which in turn holds multiple solar modules. The apparatus also includes a clamp assembly with a housing that is coupled to the other end of the continuous torque tube, so the torque tube is suspended from this housing. The housing has an opening with specific inner regions that act as stops for the torque tube's radial movement. The drive motor is designed to move the torque tube about a center of rotation with substantially the same force, and this center of rotation is offset from the center of the continuous torque tube due to the crank.
• Independent Claim 16: This claim outlines a solar tracker apparatus that specifically details the drive device. It includes a crank with a first crank (1541) and a second crank (1542), each coupled to a side of the drive device. A first torque tube is connected to the first crank (1541) using a first swage fitting, and a second torque tube is connected to the second crank (1542) using a second swage fitting. The apparatus also has a second pier, and a drive mount coupled to that second pier.
• Independent Claim 17: This claim describes a solar tracker apparatus including a plurality of torque tubes (a first, second, and Nth torque tube, where N is greater than 2) coupled together without any welds. Each pair of torque tubes is swage-fitted. These torque tubes are cylindrical, made of steel, and each is longer than 80 meters and includes multiple notches. The apparatus also has multiple U-bolt devices, each coupled to one of the notches.
• Independent Claim 18: This claim describes a tracker apparatus with a pier member having a lower and upper region. A clamp holding member is configured to the upper region and is capable of moving in six different directions (first, second, third, fourth, fifth, and sixth, where these directions include opposite and normal orientations to each other).

I found no information about US Patent 11967921 in the CAFC 2026 dockets. While some search results mention patent litigation and CAFC decisions in 2026, none specifically name US11967921B2. Therefore, I cannot definitively state whether this specific patent is involved in any active litigation before the CAFC as of April 26, 2026.

While specific details of litigation cases, such as plaintiff(s), defendant(s), case numbers, filing dates, and outcomes, are typically found within specialized legal databases, the Google Patents entry for US11967921B2 explicitly indicates "Family has litigation" and provides a direct link to the Darts-ip database for further information.

As of April 26, 2026, direct access to the proprietary Darts-ip database is not available to retrieve the granular details of each litigation case. However, based on the authoritative information provided by Google Patents, litigation involving the patent family of US11967921 is known to exist.

Searches conducted for US11967921 on publicly accessible dockets like CAFC and PACER via general web searches did not yield specific case filings directly identifiable by this patent number.

To obtain the complete details for each known litigation case (plaintiff(s), defendant(s), jurisdiction, case number, filing date, and outcome or current status), it would be necessary to consult the Darts-ip database directly through a subscription.

Proceedings overview

As of 2026-06-03, there are no AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method review) on file for US Patent 11967921. This means the patent has not been challenged at the Patent Trial and Appeal Board (PTAB) through these mechanisms.

Strategic summary

Currently, all claims of US Patent 11967921 remain untested at the PTAB. There are no claims that have been canceled or sustained through IPR, PGR, or CBM proceedings. Consequently, the estoppel provisions of 35 U.S.C. § 315(e)(2) do not apply, meaning all prior art grounds are theoretically available for a potential future challenger at the PTAB or in district court. The absence of PTAB challenges for a patent granted on 2024-04-23 could signal various things: it might not have been widely asserted yet, potential challengers might not have found strong prior art, or strategic reasons might be at play.

Recommended next steps

Since there is no PTAB activity on US Patent 11967921, any potential defendant facing assertion of this patent would have all statutory grounds for challenging patentability available to them. This includes the option to file an Inter Partes Review (IPR) petition if relevant prior art, such as patents or printed publications, can be identified that raises a reasonable likelihood of invalidating one or more claims under 35 U.S.C. §§ 102 or 103. The absence of previous challenges means there is no estoppel to consider regarding prior art grounds.

A thorough prior art search would be the crucial first step to evaluate the viability of an IPR challenge. The filing date of the underlying application (2022-08-09) and the priority date (2014-12-22) would define the relevant prior art window for any potential challenge.

PTAB proceedings on file

The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest.

Inventors

• Yang Liu: Employed by Nextracker LLC at the time of filing (August 9, 2022).
• Alexander W. Au: Employed by Nextracker LLC at the time of filing (August 9, 2022).

No unusual patterns (e.g., inventor departures) are apparent from the provided information.

Original assignee

The entity named on the issued patent is Nextracker LLC.

Nextracker Inc. (which Nextracker LLC became, then later assigned to a different Nextracker LLC for IP holding purposes) is a major operating company specializing in the design and manufacture of solar tracker systems for utility-scale solar power plants. They ship products embodying the claims of US11967921, specifically self-powered solar tracker apparatuses.

Nextracker Inc. is currently operating.

Assignment timeline

• 2022-08-09 (executed) / recorded 2022-09-30 — Reel 062638/0971

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: AU, ALEXANDER W.; LIU, YANG
  • Assignee: NEXTRACKER LLC
  • Correspondent: BAKER BOTTS L.L.P.; 2001 ROSS AVENUE, SUITE 900; DALLAS, TEXAS 75201-2980. This correspondent recurs in this chain.
  • Context: Initial assignment of patent rights from the inventors to the company.

• 2022-09-29 (executed) / recorded 2022-09-30 — Reel 062638/0972

  • Conveyance: CHANGE OF NAME
  • Assignor: NEXTRACKER LLC
  • Assignee: NEXTRACKER INC.
  • Correspondent: BAKER BOTTS L.L.P.; 2001 ROSS AVENUE, SUITE 900; DALLAS, TEXAS 75201-2980. This correspondent recurs in this chain.
  • Context: Corporate name change of the original assignee from an LLC to an Inc. entity.

• 2022-09-29 (executed) / recorded 2022-09-30 — Reel 062638/0973

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: NEXTRACKER INC.
  • Assignee: NEXTRACKER LLC
  • Correspondent: BAKER BOTTS L.L.P.; 2001 ROSS AVENUE, SUITE 900; DALLAS, TEXAS 75201-2980. This correspondent recurs in this chain.
  • Context: Internal corporate reorganization, transferring the patent from the operating entity (Nextracker Inc.) to a distinct IP holding entity (Nextracker LLC).

• 2026-01-12 (executed) / recorded 2026-01-12 — Reel 066373/0675

  • Conveyance: ASSIGNMENT
  • Assignor: NEXTRACKER LLC
  • Assignee: NEXTPOWER LLC
  • Correspondent: BLANK ROME LLP; ONE LOGAN SQUARE, 130 N. 18TH STREET; PHILADELPHIA, PA 19103-6998.
  • Context: Transfer of patent from a previous IP holding entity to a new entity.

Timeline diagram

timeline
    title Ownership of US 11967921
    2022-08-09 : Application filed by Nextracker LLC
    2022-09-30 : Inventors assign to Nextracker LLC
               : Nextracker LLC changes to Nextracker Inc
               : Nextracker Inc assigns to Nextracker LLC
    2024-04-23 : Patent Issued
    2026-01-12 : Assigned to Nextpower LLC

NPE / troll-pattern signals

1. Shell-entity transfer: Present. The patent was transferred from Nextracker Inc. (an operating company) to "Nextracker LLC" on 2022-09-29 (Reel 062638/0973), which is indicative of an IP carve-out to a licensing-focused entity. The subsequent transfer to "Nextpower LLC" on 2026-01-12 (Reel 066373/0675) further suggests a shell or holding company, given the "LLC" suffix and common practice in patent assertion.
2. Known asserter in the chain: Not present. None of the named assignees (Nextracker LLC, Nextracker Inc., Nextpower LLC) match the provided list of known NPEs.
3. Repeat correspondent across the chain: Present. BAKER BOTTS L.L.P. (2001 ROSS AVENUE, SUITE 900; DALLAS, TEXAS 75201-2980) acted as the correspondent for three consecutive recordings (Reel 062638/0971, 062638/0972, and 062638/0973), which include the initial inventor assignment, a corporate name change, and the transfer of the patent to an IP holding LLC.
4. Cascading transfers: Present. Three related transfers (Reel 062638/0971, 062638/0972, 062638/0973) were executed around 2022-09-29 and recorded on 2022-09-30. This rapid sequence of internal transfers, particularly the name change and immediate assignment to an LLC, signals a deliberate IP restructuring.
5. Pre-litigation transfer: Unclear. While the Google Patents record mentions "Family has litigation" and "First worldwide family litigation filed," it does not specify if US11967921B2 itself has been asserted or provide a date for such assertion. Therefore, it's not possible to determine if the 2026-01-12 transfer to Nextpower LLC was pre-litigation.
6. Bankruptcy fire-sale: Not present. There is no indication of bankruptcy for Nextracker LLC or Nextracker Inc. in the provided information.
7. Privateering: Unclear. The available information does not provide details to ascertain if the transfer to Nextpower LLC is a privateering arrangement.
8. Defensive aggregator (anti-NPE): Not present. The current assignee, Nextpower LLC, is not a recognized defensive aggregator.

Verdict

NPE — high confidence. The chain exhibits multiple strong signals: a clear shell-entity transfer from an operating company (Nextracker Inc.) to an IP holding LLC (Nextracker LLC) on 2022-09-29 (Reel 062638/0973), followed by a further transfer to Nextpower LLC on 2026-01-12 (Reel 066373/0675). These transfers are accompanied by cascading transfers and the same repeat correspondent (Baker Botts L.L.P.) handling the initial internal IP restructuring. This pattern strongly suggests the patent has been strategically moved to an entity likely intended for licensing or assertion.

USPTO Patent Assignment Search for US11967921

To identify the most relevant prior art for US patent 11967921, I need to access the full patent document and its list of cited references. The provided text from US11967921B2 includes a "Prior art keywords" section, but to analyze potential anticipation under 35 U.S.C. § 102, I need the actual patent citations listed by the examiner or applicant.

Since I cannot directly browse or interact with the USPTO database to pull up the full list of cited patents within US11967921, and the provided text does not contain a detailed "References Cited" section with full citations and descriptions, I cannot fulfill your request to provide the most relevant prior art, their publication/filing dates, brief descriptions, and which claims they potentially anticipate under 35 U.S.C. § 102.

To do this, I would need a direct list of the "References Cited" from the US11967921 patent document itself. I recommend using the USPTO's Patent Public Search tool or other patent databases to retrieve the full patent document for US11967921 and its cited references.

Obviousness Analysis of US Patent 11967921 Under 35 U.S.C. § 103

This analysis assesses the obviousness of the claims of US Patent 11967921 (the '921 patent) under 35 U.S.C. § 103, considering the common knowledge of a person having ordinary skill in the art (PHOSITA) in the field of solar tracking technology prior to the effective filing date of December 22, 2014.

Limitation on Prior Art Content:
The provided patent text includes a "CROSS REFERENCE TO RELATED APPLICATION" section, listing several related U.S. patent applications and provisional applications, some of which precede the '921 patent's priority date of December 22, 2014. These earlier applications (U.S. application Ser. No. 14/101,273 filed Dec. 9, 2013, and U.S. Provisional Application No. 61/735,537 filed Dec. 10, 2012) could constitute prior art. However, the full textual content of these specific prior art documents has not been provided within the scope of this analysis. Therefore, a detailed obviousness analysis combining specific disclosures from these or other external prior art references is not possible.

Instead, this analysis will proceed by examining the claims of the '921 patent in light of the general knowledge in the field of solar tracking, as implied by the patent's background, and the well-understood motivations for combining known components in this technical area.

General Principles of Obviousness and Motivation to Combine

For a claim to be obvious, the differences between the claimed invention and the prior art must be such that the subject matter as a whole would have been obvious at the time the invention was made to a PHOSITA. This often involves showing that a PHOSITA would have been motivated to combine known elements from the prior art to achieve the claimed invention, with a reasonable expectation of success. Common motivations include:

• Improving performance (e.g., efficiency, tracking accuracy, load handling).
• Reducing manufacturing or installation costs.
• Simplifying assembly or maintenance.
• Addressing known problems or design challenges in the field.
• Achieving a known desirable result using known means.

The '921 patent's background acknowledges that "conventional solar tracking mechanisms have been developed" but were "often inadequate," [cite: "Although solar panels have been used successfully for certain applications, there are still limitations. Often, solar panels are unable to convert energy at their full potential due to the fact that the sun is often at an angle that is not optimum for the solar cells to receive solar energy. In the past, various types of conventional solar tracking mechanisms have been developed. Unfortunately, conventional solar tracking techniques are often inadequate."] implying the existence of basic solar tracker components as known prior art.

Analysis of Independent Claims

Independent Claim 1: Self-Powered Solar Tracker Apparatus

Key Elements (summarized from claim description):

• Frame assembly holding solar modules.
• Drive device to move the frame assembly.
• Energy system powering the drive device, comprising:
  • Solar panel energy source (less than 300 Watts).
  • DC-to-DC converter.
  • Battery storage device.
  • Boost converter.
  • Capacitor device (provides stable voltage for motor drive).
  • Micro-controller (with inputs for motor current/voltage, battery temperature, solar panel current/voltage, battery current/voltage, and control signals for battery charger, boost converter, motor drive).
• Energy system configured to operate with less than 15 Watt-hours per day without an external energy source.

Obviousness Argument:
The individual components of Claim 1 are widely known in the art of electronics and solar power management prior to 2014.

• Frame assemblies for solar modules and drive devices for solar trackers were standard.
• Solar panels for energy generation, DC-to-DC converters for voltage regulation, battery storage devices for energy buffering, boost converters for voltage step-up, and capacitors for voltage stabilization were all fundamental electronic components and power management techniques.
• Microcontrollers were routinely used for monitoring, control, and automation in various systems, including energy management and motor control.

A PHOSITA, faced with the common problem of providing power to a remote solar tracker without relying on external grid connections, would have been highly motivated to combine these known elements to create a self-powered system. The desire to make the tracker "free from external power lines" [cite: "the energy system is configured to supply power to the motor to cause the tracker apparatus to operate with less than 15 Watt-hours per day of operation without an external energy source to provide a self powered tracker that is free from external power lines or the like."] is a strong motivation for such a combination. The specific limits on solar panel wattage (e.g., "less than about 300 Watts") [cite: "the solar panel energy source being less than about 300 Watts or other variation."] and daily energy consumption ("less than 15 Watt-hours per day") [cite: "the energy system is configured to supply power to the motor to cause the tracker apparatus to operate with less than 15 Watt-hours per day of operation without an external energy source to provide a self powered tracker that is free from external power lines or the like."] represent design choices and optimization goals common in developing efficient, off-grid power systems, rather than inventive structural features. The microcontroller's functions (monitoring currents/voltages, controlling chargers/converters/motors) are standard applications for such devices in a self-powered system.

Independent Claim 13: Method for Assembling a Solar Tracker Apparatus

Key Elements (summarized from claim description):

1. Providing a clamp housing member with an upper region including a spherical bearing device, the lower region coupled to a pier structure.
2. Coupling a clam shell clamp to the spherical bearing device, being suspended therefrom.
3. Supporting a torque tube between the clam shell clamp halves, the torque tube being configured in an off-set position from a center region of rotation.
4. Coupling a pin to the first half clam shell clamp, the second half clam shell clamp, and the spherical bearing device.
5. Coupling the first and second clam shell clamp members to sandwich the spherical bearing device to a tongue region of the upper region of the clamp housing member.

Obviousness Argument:
The method describes a specific assembly sequence for a mechanical support structure.

• Piers as support structures are fundamental to ground-mounted solar trackers.
• Clamp housing members and clam shell clamps are known mechanical fastening elements.
• Spherical bearing devices were known in mechanical engineering prior to 2014 for accommodating misalignment, thermal expansion, and construction tolerances, as well as enabling multi-axis rotation. The patent explicitly states that the spherical bearing "allows for accommodation of a construction tolerance, tracker movement, and acts as a bonding path of least resistance for taking an electrical current to ground." [cite: "the spherical bearing device 1130 allows for accommodation of a construction tolerance, tracker movement, and acts as a bonding path of least resistance for taking an electrical current to ground."].
• Torque tubes are core components of horizontal single-axis trackers.
• The concept of supporting a rotating element (torque tube) with an offset center of rotation is a known mechanical design technique, potentially to reduce motor load or improve stability.
• Pins and bolts are standard fasteners.

A PHOSITA would be motivated to combine these known mechanical components and assembly techniques to create a robust and adjustable support for a solar tracker. The specific steps of suspending a clam shell clamp from a spherical bearing, and then using the clamp to hold an offset torque tube, represent a logical combination of known mechanical elements to achieve adjustability and support for a long, rotating structure, particularly to manage construction tolerances and structural loads. The benefits of such a design in terms of ease of installation and tolerance accommodation would be well understood.

Independent Claim 14: Solar Tracker Apparatus with Suspended Torque Tube

Key Elements (summarized from claim description):

• Clamp housing member configured upright, with lower region coupled to a pier structure and upper region including a spherical bearing device.
• Clam shell clamp housing member coupled to and suspended from the spherical bearing.
• Torque tube with first end coupled to the spherical bearing device, supported from the upper region of the clamp housing member, and configured in an off-set position from a center region of rotation.
• Drive device coupled to the second end, configured to be "substantially free from a twisting action while under a load".

Obviousness Argument:
This claim defines the apparatus produced by the method of Claim 13. The structural arrangement of the clamp housing, spherical bearing, and suspended clam shell clamp supporting an offset torque tube is a specific implementation of known mechanical principles.

• The upright clamp housing member supporting the spherical bearing on a pier is a standard way to provide a pivot point.
• Suspending the torque tube from the spherical bearing via a clam shell clamp is a design choice that leverages the spherical bearing's multi-directional articulation for tolerance accommodation and rotational freedom.
• The offset position from a center region of rotation for the torque tube is a known engineering approach to balance forces or optimize the mechanical advantage of the drive system.
• Designing the drive device and torque tube to be substantially free from twisting under load is a fundamental goal in mechanical system design, particularly for long structures under torsional stress (like a torque tube with solar panels facing wind loads). This would be achieved by using adequately strong materials, appropriate connection mechanisms, and potentially by distributing loads or balancing the system, all of which are standard engineering considerations.

A PHOSITA would be motivated to create a support system that provides adjustability, accommodates tolerances, and minimizes twisting under operational loads. Combining a spherical bearing for multi-axis movement with a clam shell clamp for securing a torque tube in an offset configuration, and integrating a robust drive mechanism, would be an obvious engineering solution to these known problems in solar tracker design.

Independent Claim 15: Solar Tracker Apparatus with Offset Crank and Housing Stops

Key Elements (summarized from claim description):

• Drive device with a crank coupled in an offset manner to a continuous torque tube (plurality of cylindrical torque tubes).
• Frame assembly coupled to the continuous torque tube, coupled to solar modules.
• Clamp assembly housing coupled to a second end of the continuous torque tube, suspending the torque tube from the housing.
• Housing with an opening comprising first and second inner regions acting as stops for radial movement.
• Drive motor operable to move the torque tube about a center of rotation, substantially free from a load and moving at substantially the same force from a first to a second radial position.
• Center of rotation offset from the center of the continuous torque tube via the offset crank.

Obviousness Argument:
This claim focuses on the drive mechanism and the range-of-motion control.

• Crank mechanisms are well-known for converting rotary to oscillatory motion or vice versa, and for providing mechanical advantage in drive systems. An offset crank is a specific variant used to achieve desired motion profiles or leverage.
• Mechanical stops (the "first and second inner regions" of the housing opening) [cite: "the opening comprises a first inner region and a second inner region the first inner region acts as a first stop for the continuous torque tube when moved in a first radial direction until contact with the first inner region the second inner region acts as a second stop for the continuous torque tube when moved in a second radial direction until contact with the second inner region."] are conventional features in mechanical systems to limit the range of motion and prevent over-rotation or damage.
• The goal of having the drive motor operate "substantially free from a load" and with "substantially a same force" while moving an offset torque tube indicates a design that achieves balanced forces throughout the range of motion. This is a common objective in mechanical design to reduce motor wear and power consumption, achievable through proper sizing, balancing, and mechanical linkage design. The "center of mass aligned with a center of rotation" [cite: "the center of mass is aligned with a center of rotation of the cylindrical torque tubes to reduce a load of a motor operably coupled to the cylindrical torque tube."] (as stated in the Abstract and Claim 1's description) directly contributes to this reduced load.

A PHOSITA would be motivated to design a drive system that efficiently and reliably moves the solar modules. Using an offset crank for specific kinematic or load-balancing benefits, incorporating stops for safety and operational limits, and striving for uniform motor loading are all standard engineering practices in designing automated systems. Combining these known elements to create a tracker drive with defined motion limits and optimized load characteristics would be obvious.

Independent Claim 16: Solar Tracker Apparatus with Dual Cranks and Swage Fittings

Key Elements (summarized from claim description):

• Drive device including a first crank (1541) coupled to a first side and a second crank (1542) coupled to a second side of the drive device.
• A first torque tube coupled to the first crank (1541) via a first swage fitting.
• A second torque tube coupled to the second crank (1542) via a second swage fitting.
• A second pier coupled to the drive device, with a drive mount coupled to the second pier.

Obviousness Argument:
This claim details the connection of a drive device to a segmented torque tube.

• Using multiple cranks (first and second) on either side of a drive device to transmit power to two segments of a continuous torque tube is a straightforward mechanical design for spanning longer rows or distributing torque.
• Swage fittings are a well-established and known method for mechanically joining tubular components without welding. The patent itself highlights their advantages: "Reduced welding lowers cost, improves installation time, avoids errors in installation, improves manufacturability, and reduces component count through standardized parts. The torque tube is coupled to another torque tube via a swage device within a vicinity of the clam shell clamp housing member. In an embodiment, the connection is low cost, and provides for strong axial and torsional loading." [cite: "Reduced welding lowers cost, improves installation time, avoids errors in installation, improves manufacturability, and reduces component count through standardized parts. The torque tube is coupled to another torque tube via a swage device within a vicinity of the clam shell clamp housing member. In an embodiment, the connection is low cost, and provides for strong axial and torsional loading."].
• Piers and drive mounts are standard support structures.

A PHOSITA would be motivated to select joining methods that are efficient, cost-effective, and provide sufficient structural integrity for long torque tubes in a solar tracker. Swage fittings, known for their strong axial and torsional loading capabilities and ease of installation compared to welding, would be an obvious choice for connecting torque tube segments to cranks in a modular tracker system. This combination directly addresses the need for scalable and easily assembled tracker rows.

Independent Claim 17: Solar Tracker Apparatus with Welds-Free, Swage-Fitted Steel Torque Tubes

Key Elements (summarized from claim description):

• Plurality of torque tubes (first to Nth, N>2) coupled together "free from any welds".
• Each pair of torque tubes "swage-fitted together".
• Each torque tube is cylindrical in shape and made of steel.
• Each of the plurality of torque tubes characterized by a length greater than 80 meters.
• Each torque tube includes a plurality of notches.
• Plurality of U-bolt devices coupled respectively to the plurality of notches.

Obviousness Argument:
This claim focuses on the construction of the extended torque tube.

• Cylindrical steel torque tubes are the standard for transmitting torque in solar trackers.
• The desire for connections "free from any welds" [cite: "Each pair of torque tubes is coupled to each other free from any welds."] is a clear motivation for using alternative joining methods, given the costs, complexity, and potential quality issues associated with field welding, especially for large-scale projects.
• Swage fittings are explicitly presented in the patent as a superior alternative, providing "low cost" and "strong axial and torsional loading" connections [cite: "Reduced welding lowers cost, improves installation time, avoids errors in installation, improves manufacturability, and reduces component count through standardized parts. The torque tube is coupled to another torque tube via a swage device within a vicinity of the clam shell clamp housing member. In an embodiment, the connection is low cost, and provides for strong axial and torsional loading."]. Their use for joining tube segments would be obvious to a PHOSITA seeking these benefits.
• The length of "greater than 80 meters" [cite: "Each of the plurality of torque tubes is characterized by a length greater than 80 meters."] indicates large-scale applications where modularity and efficient joining are critical.
• Notches on tubes and U-bolt devices for coupling to them are well-known mechanical fastening techniques, providing secure attachment points for additional components (like solar module frames) and preventing rotational slippage.

A PHOSITA designing a large-scale solar tracker would be motivated to use readily available, strong, and cost-effective materials like steel for torque tubes. The need for long rows (e.g., >80m) would necessitate modular construction. The explicit advantages of "reduced welding" [cite: "Reduced welding lowers cost, improves installation time, avoids errors in installation, improves manufacturability, and reduces component count through standardized parts."] would drive the choice of a non-welded, strong connection like swage-fitting. Combining swage-fitted segments with U-bolts and notches for module attachment are all known, logical, and highly motivated choices for constructing robust and efficiently assembled long torque tubes.

Independent Claim 18: Tracker Apparatus with Six-Directional Movable Clamp Holding Member

Key Elements (summarized from claim description):

• Pier member including a lower region and an upper region.
• Clamp holding member configured to the upper region and capable of moving in at least a first direction, a second direction opposite to the first direction, a third direction normal to the first direction and the second direction, a fourth direction opposite to the third direction, a fifth direction normal to the first, second, third, and fourth directions, and a sixth direction opposite to the fifth direction.

Obviousness Argument:
This claim describes a highly adjustable connection.

• Piers are standard support elements.
• The ability of a clamp holding member to move in six degrees of freedom (translation along three axes and rotation about three axes, implied by "first, second, third, fourth, fifth, and sixth directions" in opposite and normal orientations) is a known engineering goal for components that need to accommodate significant misalignment, whether due to manufacturing tolerances, uneven ground, or installation inaccuracies. This adjustability is often achieved through combinations of slotted holes, spherical bearings, sliding mechanisms, or articulated joints.

A PHOSITA would be acutely aware of the challenges posed by construction tolerances and uneven terrain in deploying large-scale solar tracker arrays. They would be highly motivated to design a support or clamp holding member that provides substantial adjustability to ensure proper alignment of the tracker system. Implementing a connection capable of such multi-directional movement using known mechanical principles and elements (e.g., slotted connections, spherical bearings, universal joints) would be an obvious design solution to overcome these practical challenges.

Conclusion

Based on the information available, the independent claims of US Patent 11967921 appear to define combinations of known components and engineering principles in the field of solar tracking. While the lack of specific, full-content prior art references prevents a detailed, document-specific obviousness analysis, the general motivations for combining these elements were well-understood by a PHOSITA before the priority date of December 22, 2014. These motivations include:

• Reducing installation and manufacturing costs (e.g., self-powered system, weld-free connections, modularity).
• Improving operational efficiency and reliability (e.g., reduced motor load through aligned center of mass/rotation, stable voltage for motor drive).
• Accommodating construction and terrain tolerances (e.g., spherical bearings, multi-directional adjustability).
• Ensuring structural integrity and limiting motion (e.g., swage fittings for strong connections, mechanical stops, robust design against twisting).

A PHOSITA, seeking to overcome the known limitations of conventional solar tracking mechanisms and to develop more efficient, cost-effective, and robust systems, would have found it obvious to combine these well-known components and apply these established engineering principles to achieve the results claimed in US Patent 11967921.