Prior art

The most relevant prior art for US patent 11143145, as explicitly identified and incorporated by reference within the provided patent text, includes U.S. Patent No. 10,221,780 and U.S. patent application Ser. No. 14/925,441. These are considered highly relevant because US11143145 is a continuation of and claims priority to application Ser. No. 14/925,441, which itself is a continuation-in-part of and claims priority to application Ser. No. 14/738,060, which subsequently issued as U.S. Pat. No. 10,221,780. The disclosures of both parent applications are incorporated by reference in their entirety into US11143145.

Here's an analysis of these key prior art references:

1. U.S. Patent No. 10,221,780 B2

• Full Citation: U.S. Patent No. 10,221,780 B2.
• Publication/Filing Date: Issued March 5, 2019. Filed June 12, 2015 (as application Ser. No. 14/738,060).
• Brief Description: This patent, titled "Dual fuel engine with liquid fuel cutoff," describes a dual fuel engine system capable of operating on both gaseous and liquid fuels. It includes a carburetor attached to the engine intake, which connects to both fuel sources. A key feature is a liquid fuel cut-off mechanism attached to the carburetor. This cut-off is designed to interrupt the liquid fuel supply when a switch changes the engine's operation from liquid fuel to gaseous fuel, thereby preventing an overly rich air-fuel ratio during fuel crossover and mitigating issues like hard starting or unstable operation.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1: This patent potentially anticipates Claim 1 of US11143145, as it describes a dual fuel engine with an engine operable on gaseous and liquid fuel, a carburetor, a switch to change fuel operation, and a liquid fuel cut-off that interrupts liquid fuel upon actuation of the switch from liquid to gaseous fuel.
  • Claim 10: It also potentially anticipates elements of Claim 10 (a batteryless dual fuel generator), particularly the engine, carburetor with float bowl and fuel passage, a switch for fuel selection, and a fuel shutoff for liquid fuel when gaseous fuel is selected. The "batteryless" aspect might be a distinguishing feature if not explicitly covered in US10221780, but the core fuel system and cut-off mechanism are highly similar.
  • Claim 11: The description of a carburetor with a float bowl, throat, fuel passage, and a fuel shutoff with a first end in the carburetor to close the passage and a second external end to actuate it, including the "free from linear motion" characteristic (as suggested by the problem it solves, like avoiding leaks, often implying rotational valves), is also potentially anticipated.
  • Claim 16: The method of assembling such a dual fuel engine, involving providing the engine, attaching the carburetor with its fuel mixing and passage elements, coupling the switch, and attaching the liquid fuel cut-off to close the passage upon fuel switch actuation, aligns closely with the disclosure of US10221780.

2. U.S. patent application Ser. No. 14/925,441

• Full Citation: U.S. patent application Ser. No. 14/925,441.
• Publication/Filing Date: Filed October 28, 2015. (Note: This application itself is a continuation of 14/738,060, which became US10221780).
• Brief Description: As a direct parent application and continuation of the application that led to US10221780, this application would cover substantially similar subject matter regarding dual fuel engines with liquid fuel cut-off mechanisms. Without the full text of this specific application, its abstract is assumed to be very similar to, or a direct precursor to, the issued patent US10221780. It likely details an apparatus and method for delivering liquid or gaseous fuel to a dual fuel generator, focusing on preventing simultaneous fuel delivery and addressing issues related to fuel changeover.
• Potential Anticipation (35 U.S.C. § 102):
  • Given its direct lineage and the explicit statement that its disclosure is incorporated by reference in its entirety, U.S. patent application Ser. No. 14/925,441 is expected to anticipate all independent claims (Claims 1, 10, 11, and 16) of US11143145, similarly to US10221780 B2. Any differences in the claims of US11143145 from this application would likely be found in specific structural details or the "batteryless" aspect which might represent further refinement or invention.

The common problem addressed by both the prior art and US11143145 is the issue of overly rich air-fuel ratios and unstable operating conditions during cross-over switching between liquid and gaseous fuel sources, as well as delays caused by float bowls. The core solution of a liquid fuel cut-off in the carburetor upon switching to gaseous fuel is central to both.