An improved device for preventing unauthorized opening of a combination lock of the type having a plurality of tumbler wheels in conjunction with a fence-lever-actuated bolt in which a tumbler wheel assembly shield having an opening to avoid a rearward expulsion of the dial shaft provides a barrier to...http://www.google.es/patents/US4628715?utm_source=gb-gplus-sharePatente US4628715 - Tumbler wheel assembly shield for combination locks
Tumbler wheel assembly shield for combination locks
