Types of Pattern: Single piece/ one piece pattern (solid pattern), Split/ Two piece pattern, Loose piece pattern, Match plate pattern, Cope and Drag pattern, Sweep pattern, Gated pattern, Skeleton pattern, Follow board pattern

 Types of Pattern

  • Single piece/ one piece pattern (solid pattern)
  • Split/ Two piece pattern
  • Loose piece pattern
  • Match plate pattern
  • Cope and Drag pattern
  • Sweep pattern
  • Gated pattern
  • Skeleton pattern
  • Follow board pattern

Single Piece Pattern

  • Simplest pattern and inexpensive
  • Made out of one piece and does not contain loose pieces or joints.
  • Large size single castings are manufactured.
  • Moulding operations are manual and so much time is required.
  • Generally small numbers of castings are produced.
  • Material used are wood or metal (depend on quantity of production)
  • Stuffing box of steam engine.
  • It is shown in Fig.

Split Pattern

  • Castings of complicated shape can not be prepared in single piece because of some difficulties like withdrawing the pattern from the mould, etc.
  • Upper part kept on cope and lower part in drag of mould.
  • Alignment is maintained by using dowel pins. (i.e., parting line for both pattern and mould are same)
  • Taps, water stopcocks.
  • It is shown in Fig.
Split Pattern
Split Pattern

Loose Piece Pattern

Why Loose Pieces ?

Some patterns can not be removed after putting them in moulding sand. So for removing  them, they are made of loose pieces.

  • Loose pieces are attached to the main body by lower pins.
  • Main body drawn out first and then loose pieces.
  • Moulding needs more time.
  • Provides errors.
  • It is shown in Fig.
Loose Piece Pattern
Loose Piece Pattern

Match Plate Pattern

  • It has a match plate on both side of which number of split patterns are fastened.
  • Pattern of different size and shape can be fitted to a match plate.
  • Match plate is clamped with drag by locator holes.
  • Runner and gates are attached to the pattern assembly.
  • After ramming the whole assembly is removed.
  • Cope and drag fitted together-forms mould.
  • Material – Aluminium normally used because of light weight and cheap in cost.
  • Small castings are made in large scale.
  • Piston rings and IC engines.
  •  It is shown in Fig.
Match Plate Pattern
Match Plate Pattern

Cope and Drag Pattern

  • One kind of split pattern.
  • Difference is that in this gating and risering system attached to both the halves using separate metal/wooden plate.
  • Both the cope and drag parts of the final mould can be produced separately and assembled finally.
  • Used for heavy castings inconvenient to handle.
  • It is shown in Fig.
Cope and Drag Pattern
Cope and Drag Pattern

Sweep Pattern

  • It is illustrated in Fig.
  • It is a form made on a wooden board which sweeps the shape of the casting around the post/spindle.
  • It eliminates need of 3D pattern.
  • Used for producing large castings of circular section and symmetrical shapes.
  • Large bells etc.
Sweep Pattern
Sweep Pattern

Gated Pattern

  • It is shown in Fig 
  • Improvement of simple pattern
  • Gating and runner system is a part of pattern.
  • Productivity increases by eliminating preparation of gating system manually.
  • For producing small size castings for mass production.
Gated Pattern
Gated Pattern

Skeleton Pattern

  • It is shown in Fig.
  • This pattern is the skeleton of desired shape.
  •  Skeleton is made from wooden strips.
  • Strickle board is used after ramming to remove extra sand.
  • If object is symmetrical, then two halves can be moulded by using same pattern and finally moulds assembled before pouring.
  • Large castings in small numbers.
  • Turbine blades, water pipes, chutes, L – bends, etc.
Skeleton Pattern
Skeleton Pattern

Follow Board Pattern

  • It is shown in Fig
  • Follow board is a wooden board.
  • Supports pattern which is very thin and fragile. With this support, the drag is rammed, then follow board is withdrawn.
  • The rammed drag is inverted, cope is mounted in it and rammed. At this time pattern remains over the inverted drag and gets support from rammed sand and the drag under it.
  • Finally, pattern is removed and cope and drag assembled.
  • Follow board forms natural parting line in the mould.
Follow Board Pattern
Follow Board Pattern



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