Understanding Key Bar Typewriter Operation

A key bar typewriter operates through a precise mechanical sequence initiated by the typist. Understanding this sequence helps clarify how each character gets printed onto paper.

Step-by-Step Typewriter Sequence Explanation

Let's break down the operation based on the provided steps:

• A. The typist strikes the key on the keyboard: This is the starting point. When a typist presses a key, it initiates the entire printing process.
• E. Through mechanical linkage or electric triggering, a type bar is thrown up from the type basket towards the platen: The force from striking the key activates a mechanism. This mechanism causes the corresponding type bar, which holds the character, to swing upwards rapidly towards the paper.
• D. The type block strikes the ribbon: As the type bar reaches the end of its motion, the character (type block) at its tip strikes the ink-soaked ribbon that is positioned between the type bar and the paper.
• B. The ribbon transfers the impression to the sheet of paper behind it and the platen absorbs the force of the strike: The impact forces the ink from the ribbon onto the paper. The platen, a rubber roller behind the paper, provides a firm surface and absorbs the force of the type block's strike, ensuring a clear impression.
• C. As the key bar falls back into place, the carriage usually moves one unit to the next typing space and ribbon advances: After striking the ribbon, the type bar falls back to its resting position. Simultaneously, the carriage holding the paper shifts horizontally, typically by one character space, preparing the machine for the next keystroke. The ribbon mechanism also advances slightly to present a fresh section of ink for the next strike.

The Correct Operational Order

Based on this detailed explanation, the correct sequence of operation for a key bar typewriter is:

A (Strike key) -> E (Type bar thrown) -> D (Type block hits ribbon) -> B (Impression transferred, platen absorbs) -> C (Key bar returns, carriage moves).

Therefore, the sequence A, E, D, B, C accurately describes the basic operation.