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"HOME TECH": The Inner Workings

The Toilet

Yes...those tales you've heard are true. The toilet was first patented in
England in 1775, invented by one Thomas Crapper, but the extraordinary
automatic device called the flush toilet has been around for a long time. 
Leonardo Da Vinci in the 1400's designed one that worked, at least on
paper, and Queen Elizabeth I reputably had one in her palace in Richmond
in 1556, complete with flushing and overflow pipes, a bowl valve and a
drain trap. In all versions, ancient and modern, the working principle is
the same.

Tripping a single lever (the handle) sets in motion a series of actions. 
The trip handle lifts the seal, usually a rubber flapper, allowing water
to flow into the bowl.  When the tank is nearly empty, the flap falls
back in place over the water outlet.  A floating ball falls with the water
level, opening the water supply inlet valve just as the outlet is being
closed. Water flows through the bowl refill tube into the overflow pipe
to replenish the trap sealing water. As the water level in the tank nears
the top of the overflow pipe, the float closes the inlet valve, completing
the cycle.

From the oldest of gadgets in the bathroom, let's turn to one of the
newest, the toothpaste pump.  Sick and tired of toothpaste squeezed all
over your sink and faucets?  Does your spouse never ever roll down the
tube and continually squeezes it in the middle?  Then the toothpaste pump
is for you!

When you press the button it pushes an internal, grooved rod down the tube.
 Near the bottom of the rod is a piston, supported by little metal flanges
called "dogs", which seat themselves in the grooves on the rod.  As the
rod moves down, the dogs slide out of the groove they're in and click into
the one above it.  When you release the button, the spring brings the rod
back up carrying the piston with it, now seated one notch higher.  This
pushes one-notch's-worth of toothpaste out of the nozzle. A measured
amount of toothpaste every time and no more goo on the sink.

Refrigerators

Over 90 percent of all North American homes with electricity have
refrigerators.  It seems to be the one appliance that North Americans can
just not do without. The machine's popularity as a food preserver is a
relatively recent phenomenon, considering that the principles were known
as early as 1748.  A liquid absorbs heat from its surroundings when it
evaporates into a gas; a gas releases heat when it condenses into a liquid.


The heart of a refrigerator cooling system is the compressor, which
squeezes refrigerant gas (usually freon) and pumps it to the condenser,
where it becomes a liquid, giving up heat in the process.  The condenser
fan helps cool it. The refrigerant is then forced through a thin tube, or
capillary tube, and as it escapes this restraint and is sucked back into a
gas again, absorbing some heat from the food storage compartment while it
does so.  The evaporator fan distributes the chilled air.

In a self-defrosting refrigerator/freezer model, moisture condenses into
frost on the cold evaporator coils.  The frost melts and drains away when
the coils are warmed during the defrost cycle which is initiated by a
timer, and ended by the defrost limiter, before the frozen food melts. A
small heater prevents condensation between the compartments, the freezer
thermostat turns the compressor on and off, and the temp control limits
cold air entering the fridge, by means of an adjustable baffle.

Smoke Detectors

Is your smoke detector good at scaring to death spiders who carelessly
tiptoe inside it?  Have you ever leapt out of the shower, clad only in
you-know-what, to the piercing tones of your alarm, triggered merely by
your forgetting the close the bathroom door?  Is it supposed to do this?

There are two types of smoke detectors on the market; the photoelectric
smoke detector and ionization chamber smoke detector.  The photoelectric
type uses a photoelectric bulb that shines a beam of light through a
plastic maze, called a catacomb.  The light is deflected to the other end
of the maze where it hits a photoelectric cell.  Any smoke impinging on
this light triggers the alarm (as do spiders and water  roplets in the
air!).  The ionization chamber type contains a small radiation source,
usually a man-made element called Americium.  The element produces
electrically-charged air molecules called  ions, and their presence allows
a small electric current to flow in the chamber.  When smoke particles
enter the chamber they attach themselves to these ions, reducing the flow
of current and triggering the alarm.

Both types are considered equally effective and may be battery-powered or
wired to the home's electrical system. No matter which type you choose, if
you don't have one installed, put down this article and go buy one now!

And while you're signing that credit card voucher for the new smoke
detector, pause for a moment and gaze at that other technological marvel
you are probably holding in your hand, the ball-point pen.  Ever wonder
why it's called a ball-point? Because it has a ball.  The first European
patents for the handy device were issued in the late 19th century, but
none of the early pens worked very well until a Swiss inventor named Lazio
Josef Biro designed the first modern version in 1939.  He called it a
birome.  Commercial production was delayed by World War II, and then in
1945, an American firm, Reynold's, introduced "the miraculous pen which 
revolutionizes writing" at Gimbel's in New York City.  The new pen didn't
work very well and cost a whopping $12.50 U.S., but it was an instant
success. The Henry Ford of the ball-point industry, Marcel Bich, launched
the Bic pen in 1949, after developing the Biro design for two years to
produce a precision instrument which wrote evenly and reliably and was
cheap.  By the early seventies, Bic pens became the world's largest
manufacturer of ball-point pens, and today some two and one-half million
Bic ball-points aloneare sold every day in North America.

Ink feeds by gravity through five veins in a nose cone, usually made of
brass, to a tungsten carbide ball. During the writing process, the ball
rotates, picking up a continuous ink supply through the nose cone and
transferring it to the writing paper. The ball is a perfect sphere, which
must fit precisely into the extremely smooth nose cone socket so that it
will rotate freely yet be held tightly in place so that there is an even
ink flow. Although it sounds deceptively simple, perhaps the most amazing
thing about ball-point pens is the ink.  Why doesn't it just run out the
end? Why doesn't it dry up in the plastic cartridge? Bic describes the ink
as "exclusive, fast-drying, yet free flowing". The formula is, of course,
secret.

In the 19th century, writer and thinker Ralph Waldo Emerson expressed a
fear that perhaps we all feel to some extent, that "things are in the
saddle and ride Mankind". But with the help of good household reference
books, friendly reference librarians, and helpful manufacturers only too
willing to help consumers understand their products, we can at least get a
rein on the technology in our homes.