study and analysis of significance of ergonomics in designing tea cups.The study emphasis the science and role of ergonomics in designing tea cup handle.

1. BIOMECHANICS PRINCIPLES IN DESIGN OF A TEACUP
Jaikumar Ranganathan
Naveen I R
Namita Maheshwari
Aravindan M

2. FEATURES
Ceramic cup with a handle.
Basic DImensions
Outer dia. = 71.2 mm.
Thickness of ceramic = 2 mm.
Height = 64.02 mm.
Handle size: 25.02 X 49.512 mm .
handle dia . = 4.12 mm.
Weight of the cup = .10 kg.

3. Observation from the act of holding the cup:
 Weight transfer through the Joints
 Pressure Points
In the act of Holding the Cup
Thump finger, index finger and
middle fixed are involved.The
Thump finger applies pressure
on the top of the handleand
indexfinger applies the pressure
from the bottom of the handle and
middle finger supports the handle
from the sides.
By bending the wrist and holding
the cup within the fingers firmly.
The weight of the cup is transferred
to the central palm of the hand to the
elbow joint. And also part of the weight
Of the shoulder is transferred to the elbow

4. Observation from the act of drinking:
 Movement study of Joints
Shoulder joint, Elbow Joint and Wrist
Joint these are the three joints play
a vital role in drinking tea/coffee from
the cup. In the act of drinking the
Elbow joint and shoulder joint
moves forward
 In the act of drinking the weight of
the cup is transferred from the cup
to the wrist and to the elbow joint and
from elbow the weight is transferred
to the body through shoulder joint.

5. Problem Findings:
 To Balance the CG of the cup one has to put counter force using the
thump finger applyingdownward force and index finger upward force
and middle finger with other finger helps in transferring the weight of
the cup to the elbow jointand to the shoulder joint

7. w
Force(thump)
Force(middlefinger)
Indexfinger
Force analysis

8. CG
Force analysis(tilted position)

9. Problem Findings:
 If one hold the cup for a long time
while drinking .Stress is created in
the index and middle finger and
the cup tends to imbalance. As a
result automatically the other
hand holds the cup to balance

10. The user starts to bend his
head backwards as the volume
of the tea reduces.
Issue of bending the head

11. When the rim of the cup is parallel to
the face of the user, there is a conflict.
Hence the user needs to bend
backward
Why it happens?

12. Parameters considered for designing the cup handle
 Size and Shape
 Thickness
 Opening size
 Positioning of handle.

13. Ideation

14. Final Concept

15. Final Concept
Flat angular handle for
comfort grip
Handle shifted towards drinking side to
the center,for the comfort of both left
and right hand users.

16. CG of the Cup
Axis aligned with the Hand
In the proposed design of the cup
the CG of the cup is aligned with
same axis of the hand.
There by reducing stress to the
Fingers and the weight is easily
Transferred to the wrist and to
The elbow joints.

17. Courtesy to:
Course co-ordinator-Prof. G.G.Ray
IDC IIT Bombay
Thank U