Patent drawing - 1521030 - . Public domain imageRelatedPatent drawing - US1420665 - . Public domain imagePatent drawing - Pat196747 - . Public domain imagePatent drawing - 1670627 - . Public domain imagePatent drawing - USPatent4151431-1 - . Public domain imagePatent drawing - IT1090451 patent - . Public domain imagePatent drawing - Tapper patent - . Public domain imageMorePatent drawing - 1521030 - . Public domain imagefile_downloadDownloadcrop_originalOrder Printrate_reviewdescriptionSummary 1521020 patent of 1923label_outlineTagspatentspatent drawingsus patent officepatents from the united statesinventionsdate_rangeDate30/12/1924createSourceUSPTOlinkLinkhttp://uspto.gov/copyrightCopyright infopublic domain
