BALL POINT PEN--- No Substitute INVENTION

I usually don't take pen to my college .I will borrow from my friend.Yesterday, I borrowed a ball-point pen and it has no cap.I took it to the hostel by keeping it in my pantaloons.To my bewilderment,the ink has leaked and ruined my pants.At that moment,I started wondering why the ball-point pen gets leaked?I have carried pens from my school days and it has not leaked.So i started thinking.
I browsed the net and I was keen to know the working of the ball-point pen and also I want to know why doesn't all the ink is flowing out.To know answers for these question take a detailed look of the answer.

GRAVITATIONAL FORCE AND BALL DESIGN

Even though it is a generation which uses cellphones and e-mails there is no substitute for the pen and paper.These two things are necessary in our evolving day to day life.

BALL POINT PEN

REED PEN WITH THE INK

A pen is a tool used for writing and drawing with a colored fluid- i.e., ink.The ball point pen uses a rotating ball which is made up of brass,steel or tungsten carbide .Thus the name ball point.The ink gets diffused as you use the pen.
The ball point pen got very popular and it was noticed at the time of inventing this .It is very different
than its pen predecessors -- the reed pen, quill pen, metal nib pen, and fountain pen.The pens that preceded the ball point pen uses capillary action.

The problems with this technology are:

        The ink can flow unevenly.  
        The ink is slow to dry.  

ROAD TO INVENTION: 

LASZLO BIRLO

Hungarian journalist Laszlo Biro was well aware of the problems with normal pens. Biro believed that the idea of a pen using a quick-drying ink instead of India ink came to him while visiting a newspaper.  The newspaper's ink left the paper dry.To avoid clogging , he proposed a tiny metal  ball that rotated at the end of
a tube of this quick drying ink. 

The ball performs two functions:

       It would act as a cap to keep the ink from drying.
      It would let ink flow out of the pen at a controlled rate. 

WORKING:


The key to a ballpoint pen is, of course, the ball. This ball acts as a buffer between the material you're writing on and the quick-drying ink inside the pen. The ball rotates freely and rolls out the ink as it is continuously fed from the ink reservoir.

The ball is kept in place between the ink reservoir and the paper by a socket and while it is in tight, it still has enough room to roll around as you write. As the pen moves across the paper, the ball turns and gravity forces the ink down the reservoir and onto the ball, where it is transferred onto the paper. It's this rolling mechanism that allows the ink to flow onto the top of the ball and roll onto the paper you're writing on, while at the same time sealing the ink from the air so it does not dry in the reservoir.

In the case of ballpoint pen ink, the ink is very thick and quick-drying. It is thick so that it doesn't spill out of the reservoir, but thin enough that it responds to gravity. That is why a normal ballpoint pen cannot write upside-down it needs gravity to pull the ink onto the ball and the ink doesn't flow back.

Because the tip of a normal ballpoint pen is so tiny, it is hard to visualize how the ball and socket actually work.One way to understand it clearly is to look at a bottle of roll-on antiperspirant,

which uses the same technology at a much larger scale.

                                

ANTIPERSPIRANT MODEL

SOCKET

HOW THE BALL FITS INTO SOCKET

                                                      

The ballpoint pen is aptly named because the ball at the tip is the most important part of the pen.  If the ball is held in place to tightly you won't get smooth lines.  If the ball is held in place to loosely you'll get extra ink on the page.If that ball falls out completely then nothing will be holding the ink in at all and you'll get a great flood of ink in your pocket and so when there is a leakage of pen it tells the quality of pen.

When there is no cap. the movement of ball is not restricted so that ink gets leaked on the pants.When you close your cap ,the movement of ball is restricted and thus leakage problem is so less. 

  

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