Abstract: Apparatus for converting code responsive, bail operated electric typewriter into an automatic typewriter. The apparatus includes discrete sensing, actuating or combined sensing-actuating assemblies disposed in existing cavities formed by the typewriter mechanism. Each assembly connects to the typewriter frame and is positioned to respond to various selection linkages in the typewriter or to actuate them. As each assembly separately mounts to and fits entirely within existing cavities, the overall profile of the typewriter mechanism does not change.

Abstract: A combined forward and reverse indexing mechanism for an automatic typewriter. A pivotally mounted actuator arm is interposed between a common cam drive mechanism in the typewriter and either a forward indexing linkage or a reverse indexing linkage. An electromagnet selectively pivots the actuator arm to engage the forward or reverse linkage and to rotate the typewriter platen in a forward or reverse direction, respectively.

Abstract: A unit for sensing a tabulation operation in an automatic typewriter. An interconnecting member is disposed between a typewriter mainspring and a fluid clutch. This member has a disk portion nested in a hole formed in a mainspring housing. An eccentric pin portion extends axially from the disk portion and engages the mainspring while a counter-extending shaft portion engages a drive shaft from the fluid clutch. When the mainspring unwinds during a tabulation operation, it rotates the interconnecting member and drive shaft to displace an outer housing arm on the fluid clutch and close a switch thereby to indicate the occurrence of the tabulation operation.