Edward Thomas Larson

US Patent:

41556593, May 22, 1979

Filed:

Feb 5, 1940

Appl. No.:

2/317454

Inventors:

Edward S. Larson - Chicago IL
Carl A. Levin - Chicago IL
Rolf A. Thienemann - Chicago IL

Assignee:

The United States of America as represented by The Secretary of the Navy - Washington DC

International Classification:

B41J 766

US Classification:

400 90

Abstract:

1. A ciphering unit, and a printing unit having type bars movable to print he characters carried therby, an electromagnet individual to each said type bar to select the respective type bar for operation when such magnet is energized; said ciphering unit comprising driving means adapted to function in discrete cycles, a plurality of character keys, means operable by any one of said keys to initiate a functioning cycle of said driving means, an individual electric circuit closing means operable by each said key, a plurality of individually movable elements establishing variable random electric circuits equal in number to the number of said keys, each of said circuits being connected between some one of said circuit closing means and some one of said electromagnets, a switch settable to connect said circuits for flow of current therethrough in one direction for enciphering and in the opposite direction for deciphering, means individual to each said element to actuate such element sporadically to change said circuits, means separately controllable by actuation of each individual means to condition another of said individual means for operation, a common swingable bail actuated by said driving means to operate such of said individual means as are conditioned for operation, means controlled by said driving means common to all said keys to hold a key depressed until a type bar has been actuated and to prevent depression of any other key during that time, means operated by all of said keys to effect operating connection between said driving means and the instrumentalities actuated thereby, a member movable to lock said keys against depression, means responsive to the conditioning of said individual means to move said key locking member to the locked position when none of said individual means is conditioned for operation; said printing unit including means actuated to move said key locking member to the locked position when said printing unit does not operate in response to depression of a key, means operative when said switch is in the enciphering position to insert an extra space after each fifth character printed, means operable to lock said keys when a predetermined number of groups of five characters have been printed, and means operable simultaneously with the last-mentioned means to position the surface upon which said characters are printed to print a new character.