Robots with straight-line motion are great for precise grasping and handling small objects. A new mechanism with three bars was created for this purpose, making it simpler than other designs. Simulations showed it works well and can be used in various robot designs. The mechanism allows for stable output speed and can be used in industrial robots, like robot hands for grasping objects in a linear-parallel way. This new mechanism has a lot of potential for future research and applications in robotics.