1. 321 2. HELICAL SPRINGS AND U-CLAMP 3. CONTENTS Introduction (What is springs ?) Spring material Types of springs Advantages and disadvantages Helical springs Types of helical springs Clamps U-clamps 4. INTRODUCTION A spring is a resilient member capable of providing large elastic deformation. It is defined as elastic bodies (generally metal) that can be twisted, pulled, or stretched by some force. They can return to their original shape when the force is released. 5. Mechanical springs are used for a wide range of applications or uses. Their main applications are 1) To exert force, 2) To provide flexibility and 3) To store or absorb energy. 6. SPRING MATERIALS The mainly used material for manufacturing the springs are as follows: 1) Hard drawn high carbon steel 06) Inconel 2) Oil tempered high carbon steel 07) Monel 3) Stainless steel 08) Titanium 4) Copper or nickel based alloys 09) Chrome vanadium 5) Phosphor bronze 10) Chrome silicon 7. TYPES OF SPRINGS Springs are classified based on its shape or geometry, nature of stressing etc. Based on the shape/geometry they fall under 1. Wire springs, 2. Flat springs, and 3. Special-shaped springs 8. ADVANTAGES OF SPRINGS Mostly we use spring to avoid vibration because the sudden vibrations in a car may effect the human and it cause vomiting . To avoid vibrations in machines. To apply forces and controlling motion in clutches and brakes It helps in storing energy as in case of watches and toys. 9. DISADVANTAGES OF SPRINGS If the deflection of the spring exceeds some critical value than the spring will buckle . It is difficult to replace the spring Ones the spring is damaged it is difficult to repair 10. HELICAL SPRINGS A helical spring, also known as a coil spring, is a mechanical device, which is typically used to store energy and subsequently release it, to absorb shock, or to maintain a force between contacting surfaces. They are made of an elastic material formed into the shape of a helix which returns to its natural length when unloaded. 11. TYPES OF HELICAL SPRINGS 1. Open coil helical spring or tension helical spring or extension spring 2. Closed coil helical spring or compression helical spring 3. Torsion spring 4. Spiral spring 12. HELICAL EXTENSION SPRING 1. It has some means of transferring the load from the support to the body. It stretches apart to create load. 2. The gap between the successive coils is small. 3. The wire is coiled in a sequence that the turn is at right angles to the axis of the spring. 4. The spring is loaded along the axis. 5. By applying load the spring elongates in action 13. COMPRESSION HELICAL SPRING Among the four types, the plain end type is less expensive to manufacture. It tends to bow sideways when applying a compressive load. 14. TORSION SPRING 1. It is also a form of helical spring, but it rotates about an axis to create load. 2. It releases the load in an arc around the axis. 3. Mainly used for torque transmission 4. The ends of the spring are attached to other application objects, so that if the object rotates around the center of the spring, it tends to push the spring to retrieve its normal position. 15. SPIRAL SPRING 1. It is made of a band of steel wrapped around itself a number of times to create a geometric shape. 2. Its inner end is attached to an arbor and outer end is attached to a retaining drum. 3. It has a few rotations and also contains a thicker band of steel. 4. It releases power when it unwinds. 16. MANUFACTURING OF HELICAL SPRINGS 17. APPLICATIONS OF SPRINGS 1) To apply forces and controlling motion, as in brakes and clutches. 2) Measuring forces, as in the case of a spring balance. 3) Storing energy, as in the case of springs used in watches and toys. 4) Reducing the effect of shocks and vibrations in vehicles and machine foundations. 18. CLAMPS A brace, band, or clasp for strengthening or holding things together. It is a tool or a device used to hold an object in a fixed position. Types of clamps: 1) Scaffolding clamps 2) Rubber lined clamps 3) Strap clamps 4) Metal clamps 19. U-CLAMP It is made of stainless steel or mild steel. It is mainly ensured for its durability, high tensile strength and high resistivity against corrosion. They are utilized in several industries such as construction, automotive. Used to mount plain or insulated pipes. 20. REFERENCES 1) www.springer.com 2) www.indialeaf.com 3) www.engineersedge.com/spring_terms.html 4) www.sprind.com/springterm.html 5) http://nptel.iitm.ac.in 6) http://pgindustries.tradeindia.com/u-clamp- 1714229.html