A typewriter mechanism features 7 binary joints, six links, and no higher pairs. How is this mechanism classified________________?
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Answer: A. kinematically sound
Explanation
Grubler's equation calculates the degrees of freedom for planar mechanisms using links and joints. Substituting 6 links and 7 binary joints yields exactly one degree of freedom. A degree of freedom of one confirms the mechanism moves predictably and is kinematically sound. Grubler's criterion states that mobility equals three times links minus one minus two joints. Binary joints connect exactly two links together within a mechanical linkage assembly. Mechanisms must possess a positive degree of freedom to transmit motion without jamming.
Mechanical engineers apply mobility equations to verify complex machine designs before manufacturing prototypes. Typewriters rely on intricate linkages to translate key presses into precise typebar strikes. Ensuring kinematic soundness prevents mechanical binding and guarantees reliable device operation. Stating the mechanism is not sound ignores the positive mobility proven by Grubler's math. Link fixity affects inversion type but does not change the fundamental degree of freedom. Data is fully sufficient because link and joint counts are explicitly provided.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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