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Re: research ideas



In article <961123082332_353404856@emout10.mail.aol.com> YankeePerm@aol.com writes:

>Well, when I taught permaculture at a prison some years ago, my students
>worked for some months--a few of them quite brilliant guys--to come up with a
>chicken coop that closes itself at night with no external wiring.  The trick
>is to let the chickens out in a forage yard during the day, but to secure a
>door at night so that predators can't get in.  That would permit the person
>responsible to catch dinner and a movie in midsummer, when darkness comes
>late, without worrying about the hens.  Otherwise, they'll go in and later
>nocturnal predators will follow.  

The traditional mechanism for such things is a wind-up alarm clock.
This was written up in several Extension Bulletins (Oregons State
Agriculture College Extension Bulletin 480, for example).  The winding
key of an alarm clock turns when the alarm goes off, unwinding the
spring.  The "ears" of the key can trip a switch or latch, or the
turning shaft can be used as a pulley to reel a cord in or out.  This
was usually used to trip a switch to give semi-automatic control
of the lights in a laying house.  You'd set the alarm when you left
for the night, and the lights would be turned on in the morning before
dawn

For a chicken-house "pop door," you'd just have a little chicken door,
hinged at the top and held open with a string.  The string would be
attached to one of the "ears" of the alarm clocks winding key.
When the alarm went off, the ear would rotate down and drop the cord.
(I'd take the bells off the clock to keep the birds from panicking.)

You could use this in reverse to let the birds out in the morning.
This would be a two-clock, two-string solution.  The morning half
could either wind a string up to raise the door, or drop a weight
that attached to a string and pulley to the door.

	-- Robert
-- 
Robert Plamondon, President/Managing Editor, High-Tech Technical Writing, Inc. 
36475 Norton Creek Road * Blodgett * Oregon * 97326
robert@plamondon.com * (541) 453-5841 * Fax: (541) 453-4139