Monday, March 9, 2009

Before After Torticollis

MATERIALS TECHNOLOGY I - MACHINES AND MECHANISMS-

Man always tries to do work that their physical subrepasan intellectual year. Some examples of this attitude can be overcome: to move huge rocks, car lift for repairs, carrying objects or people at great distances, remove the apple cider, cut trees, solving many problems in a short time ...
To address these challenges were invented machines: a crane or a backhoe are machines, but so is a bicycle, or rocket, without neglecting the simple knife, tweezers essential, the beloved computer or binding steps. They are all common machines and have at least one thing: they are human inventions intended to reduce the effort required to perform work.
The set of pieces that transform a movement in any other mechanism is called.


Throughout this blog, try to analyze some simple mechanism, and know the different types of machines that exist. MACHINES



A machine is a set interrelated parts in a certain way and transform energy to produce a particular job and fulfill a particular function.

CLASSIFICATION OF MACHINERY


1. Simple mechanisms: Some mechanisms are called simple because they have the following features:

  • use a fulcrum
  • have a shaft and

  • have a fixed plane.

Such mechanisms are often used daily. Their advantage lies that does not pollute as its energy source is muscle. These include: lever, pulley, wheel, inclined plane and screw.


1 - SIMPLE MACHINES


Lever: is a device that moves a force from one place to another with little effort to lift a heavy load. All levers have load, effort and fulcrum (support). The effort to spin the lever at the level of support and move the load.

There are three ways to distribute the effort, load and support, these levers are called first, second and third kind. The first example is like a seesaw (first género), la carretilla (segundo género) y el antebrazo (tercer género).


PALANCA: 1er GÉNERO


Se llama de primer género cuando el eje, o punto de apoyo , está colocado entre los dos puntos de aplicación de la potencia y la resist encia.




Ejemplos:







scissors, scales, gearshift, pliers, clip, etc..






LEVER: 2nd GENDER



of the second kind is called when the application site of resistance is among the support points and power.


Examples:



Nutcracker / nutcracker, pumper, truck, bottle opener, pitted, shearing, punching, etc.





LEVER: 3rd GENDER




levers are called third gender when the point of application of power is between the points of resistance and support (or axis).


Examples:






tweezers, fishing rod, safety pin, hammer, shovel, etc.









The Inclined Plane: This is a sturdy, flat plane at an angle with respect to the horizontal axis. It is also called ramps, which can raise a heavy object at high altitude. The ramp makes work easier, because it supports almost all the weight of the object, so that little force can move upward. The longer and steeper the ramp, the easier the movement of cargo.






















winch : consists of a wheel that rotates around an axis which is wound a cord, rope or chain. By applying a force on the crank wheel to rotate, the shaft is thinner tour more strength, which makes it possible to move a heavy load with little effort. An example of this mechanism or the lathe machine is used to draw water from wells and the wheel of the Auto vile.

Pulley: is a device that consists of a disc pierced in the center by an axis that allows the disc to rotate freely. At the edge of the disk is a groove called throat, through which passes a rope, a rope or chain. The pulleys allow for a job with less effort and are used especially for heavy lifting. They are used in cranes, construction of buildings, piñatas, lifting cars in mechanical and other workshops.

pulleys are classified as:

Pulleys simple fixed

Pulleys simple mod vile

Composite Pulleys

simple Pulley :
This simple machine used to lift loads at a certain height. Simple pulley comprises a pulley attached to the ceiling or a axle, which can slide a rope. Is used, for example, to raise the buildings or objects to draw water from wells. Pulling from one end of the rope pulley handles only simple reverse the direction of the applied force. Therefore there is no mechanical advantage can only losses due to friction.


Mobile Pulley : there is nothing more than a pulley hook attached to a cord having one end anchored to a fixed point and the other (end mobile) connected a drive mechanism. In the running blocks is the fulcrum on the line and not on the axis, so movements may occur translation and rotation



















Pulley Hoist Composite or : composite pulleys are those which use more than two pulleys in the system, and can be a fixed and a moving one, or two fixed and mobile etc., throw a rope from the top down is easier said than done from below upwards. To change the direction of the effort, the movable pulley adds a fixed pulley, providing an advantage mecánica.La mechanical advantage is the reduction of the effort.



Screw: This is an example of using the inclined plane used in another way. consists of the head and a stem, which is the part in a rigid cylinder having a spiral thread bent where it goes up a nut, which in turn, as the rod goes up by pressing or joining two objects.




2. COMPOUND MACHINES: There are other machines or mechanisms more complex, comprised of many mechanical parts, or many simple mechanisms, such as are vehicles, watches, computers, tractors, engines and many otros.Para that these machines do their work should be moved, for this they need energy. The power source varies with the type of machine. Thus, the clock moves with a battery, the computer with power, the car with fuel. Some of the machines produce environmental pollution due to its power source is not muscular or electrical energy, but oil and its derivatives.
Examples:
  • The hydraulic pump was invented in 250 a. C
  • grain mills
  • Printing
  • looms and other textile machines
  • The steam
  • Harvester Tractor
  • Bicycles, etc.
ACTIVITY:
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