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Braking System The function of the braking system is to retard the speed of the moving vehicle or bring it to rest in a shortest possible distance whenever required. The vehicle can be held on an inclined surface against the pull of gravity by the application of brake. Brakes are mechanical devices for increasing the frictional resistance that retards the turning motion of the vehicle wheels. It absorbs either kinetic energy or potential energy or both while remaining in action and this absorbed energy appears in the form of heat. While moving down a steep gradient the vehicle is controlled by the application of brakes. In this case brakes remain in action for a longer period making it imperative to dissipate the braking heat to atmosphere as rapidly as possible. Automobiles are fitted with two brakes; the service or foot brake and the emer­gency or hand brake. The foot brake is used to control the speed of the vehicle and to stop it, when and where desired, by the application of force

Types of Brake The two main types of friction brake are drum brake and disc brake (Fig. 28.4). In both types a fixed (non-rotating) shoe or pad rubs against a moving drum or disc. To increase the friction between the rubbing surfaces, a special friction material is attached to the fixed part. Earlier this friction material had a high content of asbestos, but its dust is injurious to health so that a safe asbestos free friction material is nowadays used. Fig. 28.4. Types of brake. Drum Brakes. This internal expanding type of brake contains two shoes that are attached to a back-plate and are fixed to a stub axle or axle tube. The section of each shoe is of "T" shape. A friction lining is riveted or bonded to the outer face of the shoe. A drive is fitted at one end of the shoe so that the shoe expands when the brake pedal is applied. In a simple brake (Fig. 28.5) a cam is used as a shoe expander, but modern systems for cars use hydraulically operated pistons for shoe expansion.

Spy planes should come in the shape of a “bird” for better camouflage. Univerisity of Michigan has been awarded a 5-year grant of $10 millions for the development of some bat-like robotic spy planes. The bat-like spy plane has been given a acronym called COM-BAT which stands for U-M Center for Objective Microelectronics and Biomimetic Advanced Technology, which aims to re-establish the U.S Army as a world leader. The kind of bat-like spy planes are designed to provide short-term but real-time surveillance and feedback to the soldiers in the urban combat zones by using a collection of senses including sight, sound and smell. The main problem faced by the development of the COM-BAT is finding it a super lasting battery that allows it to fly long enough in the sky to collect all the necessary information for the soldiers before it drops to the ground. The development team is looking into possibility of get its power to be generated by vibrations, wind and also the sun, which the Un

Core competencies for The 7 Habits of Highly Effective People Signature Program include :- Core Competencies  Habit 1 : Participants Will Learn to: Be Proactive® Take initiative, Manage change, Respond proactively, Keep commitments, Take responsibility and practice accountability, Create positive business results. Core Competencies  Habit 2 : Participants Will Learn to: Begin With the End in Mind® Define vision and values, Create a mission statement, Set measurable team and personal goals, Start projects successfully, Align goals to priorities, Focus on desired outcomes. Core Competencies  Habit 3 : Participants Will Learn to : Put First Things First® Execute strategy, Apply effective delegation skills, Focus on important activities, Apply effective planning and prioritization skills, Balance key priorities, Eliminate low priorities and time-wasters, Use planning tools effectively, Use effective time-management skills. Core Competencies  Habit 4 : Participants Wil

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You have one drywall screw, one 1.5 V alkaline cell, six inches of plain copper wire, one small neodymium disk magnet, and no other tools or supplies. You have 30 seconds to make an electric motor running in excess of ten thousand RPM. Can you do it? Surprisingly enough, you can. Let's take a step back. The most common type of electric motor is the brushed dc electric motor. This is the kind that you'll find inside essentially everything that moves (or shakes) and runs on batteries. This type of motor attracts an electromagnet towards a permanent magnet. When the two are close enough,the polarity of the current through the electromagnet is reversed, so that it now repels the permanent magnet, and thus keeps turning. It's quite easy to build a working model; Christian built this example for his third-grade science project. A simpler yet motor (sometimes sold as the sold as the "world's simplest motor") just switches off the current for half of the cycle, le

Hypersonic Engineering & Design is a New York City based engineering and design studio working at the intersection of engineering, architecture, art, and media. CONSULTING SERVICES AND AREAS OF EXPERTISE Machine Design, Automated Systems, and Robotics Aerospace Technologies Hydraulic and Pneumatic Systems Lean Manufacturing Consumer Product Design 3D CAD Design (Solid Works, Pro/E) Structural Analysis & Finite Element Analysis Prototyping, Machining, and Small Run Manufacturing New material enables 'information sorting' at the speed of light The researchers are studying the science of ‘nano plasmonic devices’ whose key components are tiny nano scale metal structures, more than 1000 times smaller than the size of a human hair, that guide and direct light. Information is routinely sorted and directed in different directions to allow computing, internet connections or telephone conversations to take place. At present, however, computers process inf

What Your 16-Hour Workday Says About You • You’re a really hard worker • Your time is poorly managed • You don’t know what to do with your life • Your boss knows you’re gullible • At least 40% of your diet consists of pre-packaged food • You send out work emails at inappropriate hours • You have no perspective on life • You don’t sleep enough for proper brain function • You have very little self-respect • Your salary should be higher, but isn’t • You drink either too much or not enough

Brake Shoe and Pad Fundamentals 28.4.1. Brake Shoe Self Energization The drum type brake consists of two internal semicircular shoes, which are lined with friction material matching to the internal rubbing face of the drum. The shoes are fitted on a back plate, also known as a torque plate, between a pivot anchor or wedge type abutment at the lower shoe end and at the upper shoe top end by either a cam or hydraulic piston type expander. In Fig. 28.9 the expander is simply represented by two opposing arrows and the shoe linings by two small segmental blocks in the mid region of the shoes. During clockwise rotation of the drum, the upper tips of the shoes are pushed apart by the expander force, Fe, and a normal inward reaction force, N, provided by the drum, resists any shoe expansion. Consequently the drum slid over the shoe linings and a tangential frictional force Ft = \iN is produced between each pair of rubbing surfaces. The friction force or drag on the right hand shoe (Fig. 28.9)

Drum Brakes 28.5.1. Brake Layouts There are two types of drum brakes, such as externally contracting and internally expand­ing. External contracting brakes are preferred for automatic gearboxes. The internal expanding type, along with a drum, is commonly used in braking systems of vehicles. The drum brakes, used with light vehicles, are hydraulically operated. These brakes are commonly used for the rear wheels to complement a disc system at the front. This disc/drum layout permits the front wheels to undertake more braking effort. In addition, the compatibility of a mechanical hand-brake with a drum brake makes this type an obvious option for rear brakes. Various shoe arrangements in use include : • Leading and trailing shoe (L&T) • Two leading shoe (2LS) • Duo-servo. 28.5.2. Leading and Trailing Shoe (L&T) The layout of a leading and trailing shoe brake is presented in Fig. 28.14. This arrangement uses a pair of shoes pivoted at a common anchor point. The free ends of both sh