Which of the following mechanisms is an inversion of a double slider-crank chain?

• A. Elliptic trammels
• B. Beam engine
• C. Oscillating cylinder engine
• D. Coupling rod of a locomotive

Answer: (A)

An inversion of a double slider-crank chain is a mechanism that transforms the input motion into a different output motion, and an elliptic trammel is a well-known example of such an inversion. The elliptic trammel describes an ellipse as it moves, showcasing the characteristics of a double slider-crank chain being reversed.

In this context, the double slider-crank chain consists of two sliders that move along two intersecting cranks or arms, which affect the other components' motions in specific ways. The elliptic trammel, when actuated, exhibits the inversion of the original mechanism's structure and achieves a specific type of controlled motion (specifically elliptical motion), demonstrating the principles of kinematics and mechanical design.

The beam engine, oscillating cylinder engine, and coupling rod of a locomotive, while they involve complex movements and translate motion, do not serve as direct inversions of a double slider-crank chain. Instead, they follow different configurations and principles pertaining to their specific mechanisms and functions. Thus, the elliptic trammel stands out as the correct choice by illustrating the unique characteristics of a double slider-crank chain inversion.