**Lesson Plan: Technical Drawing - Locking Devices**
**Class:** Senior Secondary 3
**Duration:** 90 minutes
**Subject:** Technical Drawing
**Topic:** Locking Devices
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### **Learning Objectives:**
1. Understand the concept and importance of locking devices in engineering and construction.
2. Identify and describe various types of locking devices used in mechanical assemblies.
3. Draw and interpret technical drawings of common locking devices.
### **Materials Needed:**
- Computer and projector with technical drawing software (optional)
- Drawing boards, pencils, erasers, compasses, rulers, and paper
- Samples of different locking devices (nuts, bolts, washers, keys, pins, etc.)
- Handout with descriptions of various locking devices
### **Lesson Plan Structure:**
#### **Introduction (10 minutes):**
1. **Greeting and Attendance**: Welcome students and take attendance.
2. **Objective Overview**: Explain the learning objectives and outline the structure of the lesson.
3. **Relevance**: Briefly discuss the importance of locking devices in ensuring the safety and functionality of mechanical systems.
#### **Engage (10 minutes):**
1. **Brainstorming**: Ask students if they can name any locking devices and where they might have seen them.
2. **Real-World Examples**: Show examples of locking devices used in everyday objects (cars, bicycles, machinery) via projector or physical samples.
#### **Explain (20 minutes):**
1. **Definition and Function**: Define what locking devices are and their role in preventing movement or loosening of mechanical assemblies.
2. **Types of Locking Devices**:
- **Threaded Devices**: Nuts, bolts, and washers
- **Non-Threaded Devices**: Pins, keys, and clips
- **Special Locking Devices**: Lock washers, cotter pins, and retaining rings
3. **Detailed Explanation**: Use diagrams or samples to explain how each type works and where they are commonly used.
#### **Explore (30 minutes):**
1. **Technical Drawing Basics**: Review the key components of technical drawings (notations, scales, views - orthogonal and isometric).
2. **Practical Activity**:
- Distribute the handouts with different locking devices.
- Students will pick one or two devices to draw.
3. **Drawing Phase**:
- Provide step-by-step guidance on drawing the selected locking devices.
- Encourage the use of technical drawing equipment for precision.
#### **Elaborate (15 minutes):**
1. **Peer Review**: Students will pair up and review each other's drawings, providing feedback based on technical accuracy and detail.
2. **Class Discussion**: Discuss common challenges faced during the drawing process and clarify any misunderstandings.
#### **Evaluate (5 minutes):**
1. **Quiz**: A short quiz with multiple-choice and short-answer questions to assess understanding of the types and functions of locking devices.
2. **Collection of Work**: Collect students' drawings for assessment.
#### **Closure (5 minutes):**
1. **Summary**: Recap the main points of the lesson.
2. **Homework Assignment**: Assign a brief research task: find and bring a technical drawing of a complex locking device not covered in class for the next lesson.
3. **Q&A**: Open the floor for any final questions from students.
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### **Assessment:**
- **Formative**: Through peer review and class discussions.
- **Summative**: Evaluate technical drawings and quiz results.
### **Extension:**
- Consider organizing a workshop with a local engineer or inviting a guest speaker to discuss real-world applications of locking devices.
- Have students collaborate on a group project to design a simple mechanical assembly that incorporates various locking devices.
### **Reflection:**
- **Teacher’s Notes**: Reflect on what worked well, what didn’t, and how the lesson can be improved in the future.
- **Student Feedback**: Collect feedback from students on their understanding and engagement during the lesson.