Grippers & Tools

GRIPPERS ● These are end effectors used

to grasp and manipulate
objects during work cycles.
● Loading and Unloading
applications fall under this
category.
● Most grippers are custom
designed to owe the variety
of part shapes, size and
variety.
TYPES OF 1. Mechanical Grippers - has two
or more fingers that is actuated
GRIPPERS by robot controller
2. Vacuum Grippers - Suction
cups to hold flat surfaces
3. Magnetized Devices - For
ferrous parts
4. Adhesive Devices - Fabrics
5. Simple Mechanical devices -
Hooks and scoops
INNOVATION IN ● Dual Grippers - 2 gripper
devices in one end effector.
GRIPPERS Single gripper makes the robot
reach the production machine
twice. Once to unload the
finished part and place it out of
machine, second time to pick
next part and load into
machine. Dual grippers reduce
cycle time per part
INNOVATION IN ● Interchangeable fingers - To
accommodate different,
GRIPPERS different fingers are attached
to the gripper
● Sensory feedback - Provide
the gripper with capabilities
such as 1. Sensing the work
part 2. Applying required
pressure and force to hold the
workpiece.
INNOVATION IN
GRIPPERS

● Multiple Fingered Grippers -

Just like a human hand
● Standard gripper products that
are commercially available.
Tools
TOOLS ● The robot manipulates the tool
relative to a stationary or
slowly moving object.
● Examples - Spot Welding, Arc
Welding, Spray Painting gun,
Rotating spindle for drilling,
routing, grinding.
● Robot must not only control
the operation of tool, but also
the relative motion of tool.
TOOLS ● A robot may use multiple tools
during the work cycle. Different
types of drills.
● Must rapidly changing tools.
End effector here is
fast-change tool holder.
MATERIAL ● The robot moves materials
from one place to another.
HANDLING ● Includes:
APPLICATIONS 1. Material Transfer
2. Machine Loading / Unloading
Parts must be present to robot’s
known position and orientation.
MATERIAL ● Primary purpose is to move
parts from one place to
TRANSFER another.
● Pick and Place Robot
● Low technology robot is often
sufficient
● 2=3 joints are only required
● Pneumatically powered robots
are common.
● Delta robots are used for high
speed picking and packaging.
PALLETIZING ● Robot retrieves parts from one
location and deposits them
onto a pallet or container at
multiple positions in the pallet.
● Same pickup point, different
deposit point for each part.
● More degree of Difficulty
● Either robot must be taught the
position or it must compute
location based on dimension
of pallet and distance between
each cartons
DEPALLETIZING ● Removing parts from a pallet
and placing in another location
like conveyors etc.
● Stacking - placing one on the
other
● Insertion - robot inserts parts
into compartment of divided
carton.
MACHINE ● Robot moves parts in and out
of the production machine.
LOADING /
3 possible cases:
UNLOADING
1. Machine Loading (Loaded by
robot, retrieved by other
means)
2. Machine unloading (Loaded by
other means and retrieved by
robot)
3. Machine Loading and
Unloading (Both done by
Robot)
MACHINE Application of Loading and unloading are
used in these following processes:
LOADING /
● Die Casting
UNLOADING ● Plastic Moulding
● Metal Machine Operations (Turning
centre, finished part is in different
shape and size, so dual grippers are
used)
● Forging (Loads the raw hot billet,
holds it while forging strikes and
removes it from forge hammer)
● Pressworking (Sheet Metal)
● Heat Treating
PROCESSING ● In processing applications, the
robot performs some operation
OPERATIONS on a grinding or spray painting.
● Examples of industrial robot
applications in the processing
category include spot welding,
arc welding, spray painting and
various machining and other
rotating spindle processes.
SPOT WELDING ● Spot welding is a metal joining
process in which two sheet metal
parts are fused together at localized
points of contact.
● Robots used for spot welding are
usually large, with sufficient payload
capacity to wield the heavy welding
gun. Five or six axes are generally
required to achieve the required
position and orientation of welding
gun.
ARC WELDING ● Continuous arc welding is used to
provide continuous welds rather
than individual welds at specific
contact points as in spot welding.
● Industrial robots can also be used to
automate the continuous arc
welding process
● The fixture might be mechanized
with one or two degrees-of-freedom
so that it can present different
portions of the work to the robot for
welding.
 ● Spray coating makes use of a
spray gun directed at the object
SPRAY COATING to be coated.
● The robot must he capable of
continuous path control to
accomplish the smooth motion
sequences required in spray
painting.
● The use of industrial robots for
spray coating applications
offers a number of benefits in
addition to protecting workers
from a hazardous environment.
 Drilling, routing, and other machining
processes: These applications use a
OTHER rotating spindle as the end effector.

PROCESSING Grinding, wire brushing, and similar

operations: These operations also usc
APPLICATIONS a rotating spindle to drive the tool at
high rotational speed.
Laser cutting: The function of the robot
in this application is similar to its
function in waterjet cutting.
Riveting: Some work has been done in
using robots to perform riveting
operations in sheet metal fabrication.