Various types of Gripper mechanisms

Various types of Gripper mechanisms

Pivoting or Swinging Gripper Mechanisms:

This is the most popular mechanical gripper for industrial robots. It can be designed for limited shapes of an object, especially cylindrical work piece.

If actuators that produce linear movement are used, like pneumatic piston-cylinders, the device contains a pair of slider-crank mechanisms.

When the piston 1 is pushed by pneumatic pressure to the right, the elements in the cranks 2 and 3, rotate counter clockwise with the fulcrum F and clockwise with the fulcrum F respectively, when B < 1800. These rotations make the grasping action at the extended end of the crank elements 2 and 3.

The releasing action can be obtained by moving the piston to the left. An angle B ranging from 160° to is commonly used.

This is the swing block mechanism. The sliding rod 1, actuated by the pneumatic piston transmits motion by way of the two symmetrically arranged swing-block linkages 1--2--3--4 and 1—2—3‘—4‘ to grasp or release the object by means of the  subsequent swinging motions of links 4  and 4' at their pivots F.

A gripper using a rotary actuator in which the actuator is placed at the cross point of the two fingers. Each finger is connected to the rotor and the housing of the actuator, respectively. The actuator movement directly produces grasping and releasing actions.

The cam actuated gripper includes a variety of possible designs, one of which is shown.

A cam and follower arrangement, often using a spring-loaded follower, can provide the opening and closing action of the gripper. The advantage of this arrangement is that the spring action would accommodate different sized objects.

The screw is turned by a motor, usually accompanied by a speed reduction mechanism. Due to the rotation of the screw, the threaded block moves, causing the opening and dosing of the fingers depending on the direction of rotation of the screw.