Name : K'Pochaiah

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Department Of Technical Education Andhra Pradesh.

• Name K.Pochaiah
• Designation Senior lecturer
• Branch Mechanical Engineering
• Institute Govt .Polytechnic,Warangal
• Year\semester V semester
• Subject Manufacturing technology-II
• Subject code M-505
• Topic Milling and Gear making
• Duration 50 mins
• Sub-topic Work holding devices
• Teaching aids Visuals Diagrams

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Recap

• In the last class we have learnt about,
• Various milling operations.
• Gang milling , gear milling, angular milling, cam
  milling, end milling , profile milling ,key way
  milling .

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Objectives

• On completion of this period, you would be able
  to know about
• Various work holding devices and tool holding
  devices.
• Their constructional details and functions.

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Work holding devices

• Accuracy of the milling machine depends more on
  the way the tool and the work are held rigidly.
• Work piece must be secured on the work table and
  aligned with the cutter.

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Work holding devices

• 1. Vices 2. Clamps t bolts
• 3. V-blocks 4. angle plates
• 5. Dividing head 6. Milling fixtures
• 7. Rotary table 8. Tail stock

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Vices

• Most common work holding device.
• Directly clamped to work table.
• Clamped between fixed and movable jaw.
• 1.plain vice
• 2.swivel vice
• 3.universal vice

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Parts of a vice
Fig.1
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VICES
Swivel vice
Swivel plate
Fig.2
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VICES
Fixing vice on the table
Fig.3
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Vices

• Plain vice
• used for small regular shaped work pieces.
• Swivel vice
• fitted on circular base.
• can be swiveled to desired angle.
• to mill angular surfaces.

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Parallel bars
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VICES
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Clamps T-bolts
Fig.6
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Clamps T-bolts
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Angle plates

• To mill a surface at right angles to another
  surface.

Fig.8
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V-blocks

• Used to hold bars and shafts to cut key-ways and
  slots.

Fig.9
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Milling fixtures

• To hold irregular shaped work such as castings
  and forgings.

Fig.11
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Milling fixtures (contd.)
Milling tail stock
Fig.12
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Milling fixtures (contd.)
Dividing head

• To divide the periphery into equal number of
  divisions.
• Gear teeth and slot cutting are few applications.

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Milling fixtures (contd.)
Rotary table
Fig.13
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Summary

• In this class we have learnt about,
• Various kinds of work clamping devices.
• Vices, angle plates ,clamps ,T-bolts, V-blocks,
  milling fixtures, circular table etc.

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Quiz

• Work holding device assures
• a) accuracy
• b) safety
• c) efficiency
• d) all

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Quiz

• Circular table is used for
• a) spur teeth
• b) helical teeth
• c) straight teeth
• d) none

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Quiz

• Swivel Vice is used to mill ______________
• 
  (angular surfaces.)

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Frequently asked Questions

• 1) Explain the work holding devices in milling
  with line sketches?
• 2) List out various work holding devices in
  milling?