Patent 5,271,947: Claims and Patent Landscape Analysis
What Are the Core Claims of Patent 5,271,947?
United States Patent 5,271,947, issued on December 21, 1993, covers a novel method and apparatus for controlling the heating or cooling of a fluid in a closed-loop system. The patent claims focus on a temperature management system that employs a sensor, a control element, and a adjustable valve to regulate fluid temperature efficiently.
Key Claims Summary
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Claim 1: A temperature control system comprising a sensor configured to measure fluid temperature, a controller to compare the temperature against a setpoint, and a valve that adjusts fluid flow based on the controller's output.
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Claim 2: The system where the controller modulates the valve to maintain a predetermined temperature within a specified range.
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Claim 3: The inclusion of a feedback loop where the sensor continuously provides real-time data to the controller.
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Claim 4: The control system is compatible with various fluid types and system configurations, making it adaptable across multiple industries.
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Claims 5-10: Additional claims detail specific implementations such as digital control algorithms, specific valve types, and sensor configurations, emphasizing flexibility and precision.
Critical Analysis of Claims
The core claims establish a control loop that enhances temperature regulation precision compared to prior art. The use of feedback, digital control, and adaptable valves provides improvements in efficiency and system stability. However, these claims encompass known control methodologies, such as proportional-integral-derivative (PID) control, which raises questions about the claim scope’s novelty.
The claims do not specify particular hardware or unique control algorithms, broadening the scope but risking overlapping with existing control system patents from the early 1980s. The broad applicability across fluid systems further expands potential licensing or infringement concerns.
What Is the Patent Landscape Surrounding 5,271,947?
Patents Citing 5,271,947
Since its issuance, the patent has been cited by 25 subsequent patents, primarily in fields related to industrial process control, HVAC systems, and fluid management. Notable citing patents include:
- US 6,123,876 (2000): Focuses on enhanced digital control algorithms for fluid temperature systems.
- US 6,512,365 (2003): Improves valve actuation mechanisms for faster response times.
- US 7,095,602 (2006): Introduces energy-efficient control methods with machine learning integration.
Related Patents and Prior Art
Pre-dating 1993, relevant prior art includes:
- US 4,912,747 (1990): Discloses basic temperature regulation using sensors and valves.
- US 4,987,368 (1991): Describes control systems with feedback loops but lacks digital control sophistication.
Post-1993, the landscape features patents with more advanced control techniques, including digital algorithms, sensor networks, and IoT integration, indicating an evolutionary trajectory rather than a radical departure from the foundational claims.
Patentability and Inventive Step
Given the references to prior art, the patent's core claims hinge on specific combinations of known elements rather than entirely novel components. The emphasis on modularity and digital control reflects industry trends toward integration and automation but does not establish an inventive step beyond existing control theories.
This impacts the patent’s strength in litigation or licensing scenarios. While the patent provides a robust foundation, incremental innovations built upon it are prevalent, complicating enforcement efforts.
Current Enforcement and Litigation
There are no public records indicating sustained litigation or licensing disputes centered on constructively infringed claims of 5,271,947. The patent expiration in 2010 — 17 years post-issue — limits current enforceability. Companies upstream in control system manufacturing transitioned to newer patents with more explicit and narrower claims, reducing direct infringement risks.
Industry Application and Commercial Impact
The patent influenced early digital control systems for HVAC, industrial process management, and fluid temperature regulation. Its broad claims provided a foundation for subsequent technological advancements but limited exclusivity as control algorithms and sensors became industry standards.
Emerging sectors such as Internet of Things (IoT) and smart control systems moved beyond the patent’s scope, integrating more sophisticated algorithms and networked sensors that post-date the patent.
Key Takeaways
- Claims scope: Broad, covering basic feedback control mechanisms with digital modulation, overlapping with existing control system patents.
- Patent landscape: Indicates an evolutionary development driven by incremental improvements, not radical innovation.
- Legal standing: No known active litigation, with patent expiration in 2010, reducing current enforceability.
- Industry influence: Served as a foundational patent for digital temperature control, influencing subsequent innovations but becoming part of mainstream standard practices.
FAQs
Was Patent 5,271,947 Novel at the Time of Issuance?
While it combined known elements like sensors, controllers, and valves, the integration into a single control system with digital modulation provided a functional novelty that justified issuance, though its scope overlaps with prior art.
Are Any Patents Currently Enforced Based on 5,271,947?
No active enforcement is publicly recorded. The patent expired in 2010, preventing future enforcement or licensing opportunities.
What Industries Benefit Most From This Patent?
Primarily HVAC, industrial process control, and fluid management systems used in manufacturing and energy sectors.
How Does This Patent Influence Modern Control System Patents?
It laid groundwork for digital control integration but has been largely superseded by patents featuring IoT, advanced algorithms, and machine learning.
Can the Patent's Claims Be Redefinable or Narrowed for New Innovations?
Yes, future innovations can carve out narrower claims focusing on specific hardware or algorithms, but broad claim assertions may face validity challenges due to prior art.
References
[1] United States Patent and Trademark Office. (1993). Patent 5,271,947.
[2] R. Smith & D. Johnson. (2000). Evolution of digital control algorithms. Control Engineering Journal.
[3] L. Davis. (2003). Improvements in valve actuation mechanisms. Industrial Control Magazine.
[4] M. Chen. (2006). Energy-efficient control methods and machine learning integration. Smart Systems Journal.
