High speed printer type drum

Claim 1

IN A HIGH SPEED DRUM PRINTER APPARATUS, AN ARRAY OF HAMMERS ARRANGED ALONG A PRINT LINE PARALLEL TO THE AXIS OF THE DRUM, AN ELECTRICAL CIRCUIT FOR ACTUATING SAID HAMMERS RESPONSIVE TO A COMBINATION OF INFORMATION INPUT SIGNALS FROM A SOURCE EXTERNAL TO THE PRINTER AND TIMING SIGNALS REPRESENTATIVE OF A LINE OF TYPE CHARACTERS AVAILABLE FOR PRINTING, A PRINT DRUM SUPPORTING THE TYPE CHARACTERS FOR STRIKING BY SAID HAMMERS, SAID DRUM COMPRISING A PLURALITY OF TYPE CHARACTERS ARRANGED ON THE SURFACE OF SAID DRUM IN A PLURALITY OF ANGULARLY SPACED LINES WITH EACH OF SAID LINES HAVING INDENTICAL TYPE CHARACTERS AND BEING PARALLEL TO THE AXIS OF SAID DRUM SO THAT THE TYPE CHARACTERS ON EACH LINE ARRIVE AT SAID PRINT LINE SIMULTANEOUSLY, AND SEPARATE CHARACTER-IDENTIFYING MEANS ARRANGED ON THE SURFACE OF SAID DRUM ADJACENT TO ONE OF EACH OF SAID TYPE CHARACTER LINES WITH EACH OF SAID CHARACTER-IDENTIFYING MEANS HAVING PRECISELY THE SAME ANGULAR POSITION RELATIVE TO THE TYPE CHARACTER LINE ASSOCIATED THEREWITH SO THAT THE ANGULAR SPACING BETWEEN ADJACENT CHARACTER-IDENTIFYING MEANS IS THE SAME AS THE ANGULAR SPACING BETWEEN THE TYPE CHARACTER LINES ASSOCIATED THEREWITH EVEN THOUGH THE ANGULAR SPACING BETWEEN THE TYPE CHARACTER LINES MAY DIFFER SLIGHTLY, AND MEANS TO ADJUSTABLY SUPPORT A TRANSDUCER IN SENSING RELATIONSHIP WITH SAID CHARACTER-IDENTIFYING MEANS IN ADVANCE OF SAID PRINT LINE TO ENABLE THE PRECISE ANGULAR POSITION OF THE TRANSDUCER RELATIVE TO SAID PRINT LINE TO BE ADJUSTED WHILE SAID DRUM IS ROTATION, WHEREBY SAID CHARACTER-IDENTIFYING MEANS CORRESPONDING TO THE LINES HAVING CHARACTERS TO BE PRINTED WILL PRODUCE A TIMING SIGNAL COOPERATING WITH SAID ELECTRICAL CIRCUIT SIGNALS FOR ACTUATING THE HAMMERS TO PRINT THE TYPE CHARACTERS AT SAID PRINT LINE.