What does a break in the chain of co-pendency result in?

A break in the chain of co-pendency refers to a situation where there's a lapse in the continuity of related patent applications. When patents or applications are part of a co-pending series, typically one filing claims priority to another. This continuous connection allows each application to retain the same effective filing date as the original, which can be crucial for establishing priority of invention.

When there is a break, the subsequent applications may not be able to claim the same effective filing date as the earlier application. This means there would be no continuity in the claimed priority, leading to the preclusion of an earlier effective filing date for the new application. This loss of effective filing date can have significant implications for patentability, as it might expose the subsequent application to prior art that didn't affect the earlier application. Thus, the ability to utilize the earlier application’s filing date becomes compromised.

The other options do not accurately reflect the implications of a break in co-pendency; for instance, a break does not enhance priority or allow new filings in the sense of establishing a priority date, nor does it leave the priority unchanged. Understanding this concept is key for navigating patent law and maintaining the strategic benefits of filing strategies.