Final answer:
Flexible couplings are used to transmit forces around corners, accommodating misalignments and vibrations while keeping the force direction parallel to the connector.
Step-by-step explanation:
The general role of flexible couplings is to transmit forces around corners while accommodating misalignments, vibrations, and expansions in machinery. These couplings are crucial in various applications, such as hospital traction systems, finger joints, or bicycle brake cables.
When there is no friction, flexible connectors allow the tension to be transmitted undiminished, altering only the direction of the force which remains parallel to the connector itself, ensuring that the mechanical link remains intact and functional even when not in a straight line.