Adjustable length element includes a first member having threads and a second member having threads. The adjustable length member also includes at least one protrusion on one of the first member and the second member, with the at least one protrusion being capable of engaging and disengaging at least...http://www.google.de/patents/US6811557?utm_source=gb-gplus-sharePatent US6811557 - Adjustable length member such as a cap of a lancet device for adjusting penetration depth
