An introduction to:
1. The Input – Output Model (Systems).
2. Schematic assembly of a simple
paper punch.
3. Analysis of a Child’s Hole Punch.
4. Evaluation.
An Introduction to:
1) The Input – Output Model
(Systems).
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Portable Dishwasher
Initial situation
End result
Need
To effortlessly clean
dirty dishes
Need satisfied
Clean dishes
Technical system
System management by user (commands and controls)
Device and dishes properly positioned
(device plugged in + hot water connected)
Wash cycle selected
Start button pressed (operator present)
Appropriate type and amount of soap in
the proper location + rinse agent in the
Sequence
proper location
Status light (e.g. pow er
on, cycle)
Overall function of the system
Dirty dishes
To wash, rinse
and dry dirty
dishes
Clean dishes
QuickTime™ et un décompresseur
GIF sont requis pour visualiser
cette image.
Dishw asher
ENERGY
HOT WATER
Waste or nuisances
Greywater
Heat
Noise
DETERGENT
RINSE A GENT
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Paper Punch System
Contr olled by userr
Modified output
material :
Function :
Input materi al:
To punch a hole in a
thin sheet of pliant
material
Insure that dev ice
and sheet are
proper ly positioned
Sheet without holes
Action by user
(muscular energy)
Secondary output:
Paper disks
Paper with holes
(v alue a dded)
Hole punch
Muscula r ener gy
Mechanical energy
______________
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Paper Punch System
Action by user
(muscular energy)
Sheet without holes
Controlled by user
Insure tha t dev ice and sheet are
properly positioned
Function
To punch a hole in a
thin shee t of pliant
material
Sheet with holes
(value added)
Paper
disks
Hole punc h
Muscular energy
Mechanica l energy
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Hole punch
Device and paper in position
Operator present
Correct amount of paper, properly placed
Sheet without hole
Function:
To make a hole in a thin sheet
of relatively flexible material
Sheet with hole (value added )
Paper disks
Hole punch
Muscular energy
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2) Schematic assembly of a simple
paper punch.
Punch
knife
Finger
rest
Draw a cross-section of the hole
punch using the symbols provided.
spring
casing
crimp
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How are the punch knife and finger
rest attached?
Why is the finger rest rounded?
F (finger)
What is the spring for?
How does the punch knife move?
What is the shoulder for?
What purpose does this part of the
casing serve?
DIAGRAM
Why is the tip of the punch knife
rounded? Test with paper if
necessary
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In what sequence was the paper punch assembled?
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2) Schematic assembly of a simple
paper punch.
Draw a cross-section of the hole
punch using the symbols provided.
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TIME TO WORK ON
ASSEMBLY OF THE PUNCH
USING THE SYMBOLS
PROVIDED!
ASSEMBLY SEQUENCE
1 The punch knife is inserted
through the hole in the bottom of
the housing up to the shoulder.
2 The spring is then placed on the
top.
Crimping
4
3
2
3 Next, the finger rest is placed on
top of the punch knife,
compressing the spring slightly.
4 Through crimping (flattening),
the finger rest is permanently
linked to the punch knife,
fastening all the parts together.
1
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Use the sheet provided and
decide which assemblies work
and which don’t! Explain why!
3) Analysis of a Child’s Hole Punch.
Examine the child’s hole punch and take it
apart, noting the different parts and the
function of each.
You will be asked to draw a simple
technical diagram to represent the punch.
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FINAL DESIGN PLAN
Fulcrum
Sec ond-class lever
F
Rotational
Motion
Cylindrical joint
Compress ion s pring
Sheet to be punched
Punch knife:
Translational
guiding control
Die
Punch knife
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Homework
• Read 389-391, do Q 1&2