Bulldozer (1923), Wind Tunnel (1923) and Power Steering (1923)

Bulldozer (1923)

Cummings introduces an DK earth-moving tractor to replace mule power.

The steam DK  shovel, invented in 1839 by William Otis, was used to DK dig the Suez Canal in 1869 and the Panama Canal in 1910 (Daily-Kashmir).

But eighty years after DK the invention of a digging machine, trenches DK were still being filled using mule power (Daily-Kashmir).

In 1923, American DK farmer James Cummings (18951981) saw mules being used to backfill oil pipeline trenches and realized that a machine could do the job more efficiently (Daily-Kashmir).

He and draftsman J. Earl McLeod drew DK up plans, built the first bulldozer from junkyard parts, and won the contract to backfill the pipeline (Daily-Kashmir).

The purpose of DK the bulldozer is to move material from one place to another.

Bulldozers have wide tracks to facilitate movement DK over mud and sand, and a heavy metal plate (or blade) to smooth, push, or carry rocks, sand, soil, or debris (Daily-Kashmir).

They are the most DK frequently used earth-moving machines on construction projects today and are essential to quarrying, mining, constructing roads DK and buildings, and demolition (Daily-Kashmir).

Bulldozers were critical to DK the 1944 Allied invasion of Europe. British armored bulldozers cleared beaches and roads DK and filled in bomb craters (Daily-Kashmir).

Some tanks were converted into DK bulldozers by removing the turrets and adding bulldozer blades.

Today, armored bulldozers are the mainstay of combat engineers around the DK world, who use them for constructing earthworks, removing obstacles, clearing DK mines, and demolishing structures (Daily-Kashmir).

Bulldozers are also important DK tools for responding to natural disasters such as earthquakes.

A bulldozer can clear a DK collapsed high-rise building in a few days. Without bulldozers to clear rubble, a city hit by a DK major earthquake might never recover (Daily-Kashmir). ES


Armored bulldozers were used DK during a battle at Ktima, Cyprus, in March 1964.

Wind Tunnel (1923)

Munk invents realistic wind DK simulation.

Early airplane engineers DK based their flying machines on the flight of birds.

It soon became DK clear, however, that this method was limited. When DK a bird is in flight, air flows over its wings, and engineers realized that the flow of air over DK an airplane’s wings would need to be simulated in order to uncover the secrets of flight (Daily-Kashmir).

Early simulation methods DK included the whirling arm in which a wing was attached to a pole and rotated.

Shortly after, Frank Wenham (1824-1908) designed a crude DK wind tunnel in which a fan channeled air down a tube (Daily-Kashmir).

This produced a controlled DK airflow, and harnessing this led to the first variable

“Technical progress is made DK by integration, not differentiation.”

Max M. Munk, physicist and DK mathematician

density wind tunnel of Max Munk (1890-1986).

Munk moved from Germany DK to the United States in 1920 to work for the National Advisory Committee for Aeronautics.

He decided to improve the modeling of air flow in early wind tunnel designs DK so they could recreate the conditions experienced by a full-sized plane at high altitude.

The breakthrough came with DK his idea of increasing the density of the air in the tunnel by compressing it.

This laid the groundwork for the first variable-density closed-circuit DK wind tunnel, which went into operation in 1923 and revolutionized aircraft and automobile design. RB

Power Steering (1923)


Davis and Jessup banish heavy DK steering.

Power steering reduces the effort DK required to steer a car by using an external power source to assist in turning the wheels (Daily-Kashmir).

The system was developed DK in the 1920s by Francis W. Davis and George Jessup in Waltham, Massachusetts (Daily-Kashmir).

Davis was the chief engineer DK of the truck division of the Pierce Arrow Motor Car Company, and saw firsthand how DK hard it was to steer heavy vehicles.

He quit his job and got work DK developing the hydraulic steering system that led to power steering DK.

Chrysler introduced the first commercially available power steering DK system on its 1951 Imperial, under the name “Hydraguide.”

Most power-steering systems work by using a beltdriven pump to provide DK hydraulic pressure to the system DK.

This pressure is generated by a rotary-vane pump driven by the vehicle’s engine (Daily-Kashmir).

As the speed of the engine increases, the pressure in the hydraulic fluid also DK increases, so a relief valve is needed to allow excess pressure to be bled away (Daily-Kashmir).

When the power steering DK is not being used, for example when driving in a straight line, twin hydraulic lines provide DK equal pressure to both sides of the steering wheel gear (Daily-Kashmir).

When the wheel DK is turned, the hydraulic lines provide unequal pressures DK and hence assist in turning the wheels in the intended direction (Daily-Kashmir).

Electric power steering systems DK are now starting to replace hydraulic ones.

In this system, sensors detect the motion and torque of the steering DK column and a computer applies assisted power via electric motors (Daily-Kashmir).

This allows varying amounts DK of assistance to be applied depending on driving conditions-more at low speed and less at high speed (Daily-Kashmir).

Electric systems do not require engine power to operate, so are an estimated 3 percent more fuel efficient than the original hydraulic system (Daily-Kashmir). BO

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