Mee 235: Engineering Technology: H.A. Ajimotokan (PHD)
Mee 235: Engineering Technology: H.A. Ajimotokan (PHD)
235: Engineering
Technology
❑ Contents Outline
1. Introduction
2. Objectives
3. Main Content
3.1 Plant and Workshop Layouts
3.2 Sections/ Types of Workshop
3.3 General Safety Rules and Work Procedures
in Workshops
4. Summary
4
1. Introduction
❑ building work,
❑ pattern making for concrete or casting
work,
❑ furniture, cabinet making, etc.,
❑ joinery, i.e. preparation of joints.
❑ T h e s y s t e m o p e r a t e s b y a b s t r a c t l y
programmed commands,
❑ Contents Outline
1. Introduction
2. Objectives
3. Main Content
3.1 What Industrial Safety is
3.3.1 Objectives of Industrial Safety
3.2 Accidents
3.2.1 Causes of Accidents
3.2.2 Types of Accidents
3.3 Personal Protective Equipment
3.4 Safety Rules
3.5 Fire and Safety
3.5.1 Classes of Fire
3.5.2 Types of Fire Extinguisher
4. Summary 34
1. Introduction
43
3.2.2 Types of Accidents Contd.
(a) Welding shield (a) Operational eye shields (c) Welding goggles
Figure 2.2: The eye protective devices, showing the welding shield in (a),
46
eye shields in (b), and welding goggles in (c)
3.3 Personal Protective Equipment Contd.
❑ The types of safety boot/ shoe also depend on the type of activity
being undertaken.
(a) Coverall
(b) Aprons
64
3.5.2 Types of Fire Extinguisher and Suitability Contd.
❑ Contents Outline
1. Introduction
2. Objectives
3. Main Content
3.1 Lathes
3.1.1 Types of Lathes
3.1.2 Functional Parts of a Lathe
3.1.3 Specifications of Lathes
3.1.4 Lathe Operations
3.1.5 Cutting Parameters
3.2 Milling Machines
3.2.1 Types of Milling Machines
3.2.2 Size of a Milling Machines
3.2.3 Depth of Cut
3.2.4 Types of Milling Operations
3.2.5 Operations Performed on Milling Machines
3.2.6 Dividing Heads
3.3 Screw Machines
3.3.1 Types of Screw Machines
3.3.2 Functional Parts of a Screw Machine
3.3.3 Different Operations of a Screw Machine
3.4 Fabrication Technology
3.4.1 Basic Fabrication Technology
3.4.2 Fabrication Project
68
4. Summary
1. Introduction
Using any tool, safety is a number one priority. All tools have
one thing in common, i.e. they can cause serious injury.
❑ Proper safety equipment should be worn at all times and all
safety procedures followed when operating any tool. 77
3.1 Lathes
Figure 3.1: Pictorial illustration of a metal spinning speed lathe, indicating its parts 82
3.1.1 Types of Lathes Contd.
Like the speed lathe, it has all the basic parts, e.g., bed,
headstock, and tailstock among others.
Unlike the speed lathe, the centre lathe can feed the
cutting tool
❑ both in cross and longitudinal direction with reference
to the lathe axis
❑ with the help of a carriage, feed rod and lead screw; 84
3.1.1 Types of Lathes Contd.
Figure 3.2: Pictorial illustration of a centre lathe, indicating its principal parts
Duplicating lathe is
❑ used for duplicating the shape of a flat or round
template onto a workpiece. 90
3.1.2 Functional Parts of a Lathe
Figure 3.3: Schematic configuration of a centre lathe, indicating its functional parts
Figure 3.4: Schematic illustration of a centre lathe’s tailstock, indicating it main parts 96
3.1.2 Functional Parts of a Lathe Contd.
Figure 3.6: Schematic illustration of a lathe dog, indicating its typical use on lathe 102
3.1.2 Functional Parts of a Lathe Contd.
❑ The mandrel is always rotated with the help of a lathe dog and
catch plate, and it then,
❑ drives the workpiece by friction. 108
3.1.2 Functional Parts of a Lathe Contd.
❑ operations performed
❑ by holding the workpiece by a chuck, faceplate or
angle plate,
❑ e.g. undercutting, parting-off, internal thread
cutting, reaming, etc 117
3.1.4 Lathe Operations Contd.
❑ For this operation, the workpiece may be held in a chuck and rotated
about the lathe axis.
❑ A facing tool is fed perpendicular to the axis of the lathe. The tool is
slightly inclined towards the end of the workpiece.
123
3.1.4 Lathe Operations Contd.
❑ Cutting speed - refers to the speed at which the tool point of the
cutting tool moves with respect to the workpiece,
❑ measured in metre per minute.
❑ The column and knee type milling machines are classified based on
the
❑various methods of power supply to the table,
❑different table movements and various main spindle axes of
rotation. 134
3.2.1 Types of Milling Machines Contd.
❑ This, in turn,
❑ speeds up the machining operation and
❑ decreases the amount of tool bits change out. 159
3.3.1 Types of Screw Machines Contd.
❑ The feed screw works along with the lead screw to drive
the spindle,
❑ which in turn spins the machined workpiece. 163
3.3.2 Functional Parts of a Screw Machine
❑ Machine tools are any of a class of power-driven devices designed for carrying out specific
machining operations in order to produce a desired size, shape and surface finish of workpiece
being machined.
❑ The productivity of a machine tool is measured either by the number of parts produced in a
unit of time, volumetric removal rate, or specific removal rate per unit of power consumed.
❑ Machine tools, according to their specialisation can be divided into general-purpose (universal
or standard), special-purpose, and limited-purpose machines.
❑ main functions of machine tools are for
❑ holding the workpiece to be machined, holding the tool, and achieving the required
relative motion to generate the required workpiece geometry.
❑ Contents Outline
1. Introduction
2. Objectives
3. Main Content
3.1 Measuring and Marking Tools
3.1.1 Vernier Calipers
3.1.2 Calipers
3.1.3 Micrometer
3.1.4 Scriber and Surface Gauges
3.1.5 Try Squares
3.1.6 Spring Dividers
3.1.7 Centre and Dot Punches
3.1.8 Surface Plates
3.2 Work Holding and Supporting Tools
3.2.1 Workbenches
3.2.2 Bench Vices
3.2.3 Vee Blocks
3.2.4 C-Clamps
3.2.5 Angle plate 172
Contents Outline Contd.
❑ The vernier caliper has two jaws - the external jaws, located at
one end of its main scale and the internal jaws, which is made as
part of a vernier scale. 177
3.1 Measuring and Marking Tools Contd.
182
3.1 Measuring and Marking Tools Contd.
Figure 4.10: Pictorial illustration of a bench vice, showing its essential parts
❑ It consists of a
❑ frame, made of mild steel and
❑ a blade, made of high carbon steel or high-speed steel,
❑ which is set in the frame and tightened with the help
of a flange nut.
❑ The teeth of the blades are generally forward cut such that,
❑ the pressure is applied in the forward direction only while the
backward direction is idle.
❑ It is used for
❑ removing surplus metal,
❑ cutting thin sheets or chipping any material softer
than the chisel itself.
Figure 4.15: Schematic illustration of a chisel, indicating its cutting edge geometry
❑ Flutes are incorporated to carry away the chips of metal and the outside
surface
❑is relieved to produce a cutting edge along the leading side of each flute. 206
3.3 Cutting Tools Contd.
❑ The drill shank is the end that fits into the chuck of a
hand or power drill. 207
3.3 Cutting Tools Contd.
Figure 4.16: Pictorial illustration of a twist drill, indicating its essential cutting
edge features 208
3.3 Cutting Tools Contd.
❑ The hand taps are typically supplied in sets of three taps for
each diameter and thread series to cut any particular size. 209
3.3 Cutting Tools Contd.
(a) Taper
(b) Plug
(c) Bottoming
Figure 4.17: Pictorial illustrations of hand taps, showing the taper in (a), plug in (b) and
bottoming in (c) 210
3.3 Cutting Tools Contd.
There are many types of wrenches for turning taps and dies.
❑ These include the T-handle and adjustable tap wrenches, and
❑ diestock for round split dies, are a few of the more common
types. 212
3.3 Cutting Tools Contd.
(a) Maul
❑ Box-end wrench has double ended boxes and also offset to clear the
user’s hand.
❑ The boxes completely surrounds the nut or bolt and usually has 12
points so that the wrench can be reset after rotating only a partial
turn.
❑ Socket wrenches are similar to the box wrenches because they also
surround the bolt or nut and are usually made with 12 points,
contacting the six-sided bolt or nut.
❑ used with socket head cap screws and socket setscrews, and are
made detachable from various types of drive handles. 225
3.5 Miscellaneous Tools Contd.
4. Summary
❑ Tool refers to any device or instrument, especially one held in the hand,
which is used to carry out a particular function, like the production of a
product or any related activities.
❑Hand tools are tools that are manually controlled.
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