How does the K-B corer work?

Aircraft cable fits into a closing trip mechanism at the stop of the head assembly. When a messenger strikes the trip lever, a neoprene valve drops and seals the core tube under the head assembly. A suction, formed between the top valve and the core sample, creates a partial vacuum inside the core tube as the sampler is raised. This partial vacuum helps hold the sample in the core or liner tube, thus allowing collection of all but the soupiest samples.