Special purpose tool

The proper feeder capable of providing preferred orientation is selected after studying the preferred orientation of part shape and profile. The preferred orientation is then changed to required orientation by track and escapement design or pick-and-place mechanism.

Arrangements to detect feeder malfunctions, for fall out of dirt or foreign material on track, removable track covers at points of likely jams etc. With increase in automation, electro-mechanical limit switches constitute most important communication mechanism.

These switches usually have single-pole contact block with one normally open NO and one normally closed NC contacts. Time delayed contact limit switches are used for detecting machine jam-up by causing switch to remain actuated beyond a predetermined time interval.

Maintained contact switches are used where a second definite reset motion is desired. Push-in roller limit switch is used for linear or rotary cam actuation. Forked roller lever limit switch is used for reversing operations. Wobble stick limit switch is used for actuation in variety of directions. In addition, a very wide variety of limit switches are available. Proximity Switches are also essential with increase in automation. These sense presence or absence of a target without touching it.

The various types are magnetic, capacitive, ultrasonic, inductive and photoelectric. Magnetic switch is made of a magnetically-activated reed and a stationary contact. When a magnet is brought towards the switch an induced magnet field causes the movable reed to close upon the stationary contact.

It is the simplest device, low in cost, can be operated on AC or DC supply and can operate in dusty environment.

Capacitive type proximity switch consists of a sensing plate forming one side of a resonating capacitor which forms part of a tuned oscillator circuit. When an object is brought close to the sensing plate, the oscillator produces a signal which is rectified to trigger output circuitry.

It can sense metallic and non-metallic targets but is sensitive to temperature change and is affected by humidity changes. In ultrasonic type of proximity switch, a transmitter directs an ultrasonic signal to a receiver mounted in a remote location.

When an object interrupts the beam, the output device is tripped. Wide range of distance sensing is possible and this device can operate satisfactorily in dirty or wet environments. However, targets must be non- porous. Its working is affected by rapid air movement and its accuracy is relatively low.

Radio frequency inductive proximity switch consists of an oscillator that produces a radio frequency signal. It is very fast in operation and can sense all conductive materials and has high repeatability. Photoelectric proximity switches consist of light-emitting-diode LED emitting light in the infrared region, and a pulsed or modulated signal prevents most ambient-light interference.

It can detect all materials in sizes upto fine wires. Dirty atmosphere can clog the lens and hence affect performance. Fibre Optic Scanners are also finding wide applications in machine tools. These are resistant to shock, vibration, moisture, corrosion, environment temperature, electrical noise. The sensing tips are extremely small and available in a number of shapes. For counting parts, electric scales are used.

Control systems for machine tools range from relay panels, programmable controllers, computerised numerical controllers and drive systems to highly complex computers. An automated factory consists of any of these in combination with robots, distributed control, and data communications networks. Programmable controllers have been very effective in improving production line uptime, lower maintenance cost, increasing production volume and product uniformity, optimum space utilisation etc.

The programmable controllers used should be compatible with the communications network. Most of the drives of machine tools and controls require electric power supply.

Uninterrupted power supply obtained by batteries or back up engine generators is essential for computer systems. High production rates and high costs of idle time and materials demand that no part of a plant should be shut down unnecessarily. Microprocessor technology is being used to achieve circuit protective devices to obtain precise co-ordination. Power supply for microprocessor based equipment should be clean, i.

The rotary shafts and linear motion members are most important for any machine tool. The use of high efficiency motors is desirable. Since drive efficiency is the product of all drive component efficiencies, all drive line components should be efficient. This also reduces heat dissipation, thereby extending equipment life. Adjustable speed drives play a greater role in energy conservation. Both AC and DC motors are available with adjustable speeds. DC motors with no brushes and easily replaceable modular components are available.

Hydraulic and mechanical adjustable speed drives are also available. It is extremely wear resistant which makes it ideal for brick mold, sand slingers, shotblast liners and extrusion tool applications. The high vanadium content results in several large hard carbides that aid in resistance to surface abrasion. It is not well suited for slitting or cutting applications because of the large carbides.

Cru-Wear is a cold work air-hardening tool steel that is heat treatable to HRc. It has a good combination of toughness and wear resistance and can be considered an upgrade to D The Jointer -- is a "must-have" tool if you're planning to build cabinets or furniture. Its purpose is to plane the edges of boards so smoothly that you can join them together into wide panels without unsightly glue lines.

The Bandsaw -- will cut tight or sweeping curves with matchless speed and precision. And, since it offers a more generous depth-of-cut than a table saw or circular saw, it's also often the best choice for cutting stock up to 6" thick.

The Scroll Saw -- will amaze you with its extremely intricate, internal or external cuts straight or curved in stock up to 2" thick. This is a prime evolutionary example of what we used to call "jigsaws" - just far, far superior! The Thickness Planer -- will significantly improve the fit of your project components and therefore, the quality of your projects Belt Sander. Scroll Saw. Strip Sander. Power Stands. Power Station.