Abstract: An interposer in a typing machine key action is supported by an arcuate spring and a shelf. When a key lever bears against the arcuate spring to release the interposer from the shelf, the arcuate spring snaps the interposer against a pawl that engages a power roll to initiate a typing operation. Potential energy is restored to the arcuate spring as the key lever lifts the interposer back to rest position. The arcuate spring serves as a support and frictionless pivot for the interposer and biases the interposer against the shelf while providing energy to impel the interposer against the pawl.

Abstract: A gap is provided between two teeth on a power roll in a typing machine repeat key action, and a cam follower surface is provided on a repeat interposer. A repeat typing operation can be initiated only when the cam follower surface engages the gap. When the key action is not in a repeat position, a latch and a forked lever cooperate to hold the repeat interposer away from the power roll; when the key action is in the repeat position, the forked lever holds a single-action interposer out of the way. The gap prevents skipped and uneven repeat typing operations during high-speed operation by giving the actuator and the typebar enough time to settle into rest position.

Abstract: A drive system for an electric typewriter has a power roll driven by an electric motor through a drive belt and a pulley rotatably mounted and resiliently connected to the power roll. The driving energy transmitted to the type action of the machine is controlled by energy-absorbing means adjustably connected to the power roll pulley and controlled through appropriate linkage by the machine operator to vary the energy absorbed by the resilient connection between the power roll and the pulley. A self adjusting means is also provided to set the proper tension on the drive belt of the drive system.