Grippers

Mechanical Grippers

Mechanical Gripper

• The mechanical gripper is used as an end effector in a robot for grafting the object with its mechanically operated finger 
• In industries, two fingers are enough to holding purpose more than three fingers can also be used based on the application 
• A robot required as a hydraulic electric or pneumatic drive system to create the input power
• The power produced in sense is to gripper for making the fingers react it also allowed the fingers to perform open and closed actions.
• Most importantly, Sufficient force must be given to hold the object.
• In mechanical gripper, the holding of an object can be done by two different methods As given below

1. using the finger pad as like the shape of the verb part
2. using soft material finger pad 

• In the first method, the contact surface of the fingers are designed according to the work part of for achieving the estimated shape it will help the fingers to hold the work part for some extent 
• The grippers must be capable of supplying sufficient to hold the work part. To avoid sketches on the work part stock type are fabricated on the fingers.

vacuum gripper

• vacuum cups also called suction Cup can be used as a gripper device
• The usual requirements on the object to be handled are that they be a flat, smooth, and clean condition necessary to form a satisfactory between the object and suction cup.
• The suction cup used in this type of robot people are typically made of Elastic material such as rubber or soft plastic.
• An exception would be when the object is to be handled is composed of a soft material, in this case, the suction Cup would be made of a hard substance.
• The shape of the vacuum Cup is usually round.
• Some means of removing the air between cups and the part surface to create the vacuum is required. The vacuum pump and Venturi are two common devices used for this purpose.
• The vacuum pump is a pump Piston operated or when driven device powered by an electric motor it is capable of creating a relatively high vacuum.
• Venturi is a simple device that can be driven by means of the air pressure its initial cost is less than that of a vacuum pump and is relatively reliable because of its simplicity.
• However, the overall reliability of the vacuum system depends on the source of air pressure.

Magnetic gripper 

• The magnetic gripper uses an electromagnetic or permanent magnet type of effect to pick up metallic objects.
• The simple method to grasp ferrous material is to use a magnetic gripper.
• The principle used is the same as vacuum expect that cups are replaced by magnetic grippers. This type of gripper can handle metal parts with holes quickly.
• Electromagnetic grippers are easier to control but they required a source of electric power.
• The permanent magnet, however, has the disadvantage of a lack of control during some duration of a cycle.
• A significant feature of the magnetic gripper is that leaves the little to no residual magnetism when turned off, therefore, releasing the part instantly.
• Magnetic gripper, despite its compact size, can substance in enormous holding power.
• Its lightweight design reduces wear on automatic equipment.

Adhesive gripper

• In a gripper design, an adhesive substance can be used for grasping action.
• The primary requirement in such an arrangement is that the items to be handled must be grouped on the one side only.
• The reliability of the adhesive ripple is diminished with each successive operation cycle as the adhesive substance loses its thickness with repetitive use.
• This efficiency can be overcome by loading the adhesive material in the form of a continuous ribbon into the feeding mechanism attached to the wrist of the robot.