[net.physics] Gravity-based drive mechanism

trough@ihuxi.UUCP (Chris Scussel) (03/25/85)

The "Tomorrow" section of the Chicago Tribune for Sunday, March 24 had
an article about a vehicular "drive" that "uses" gravity. A diagram
of the mechanism was included, as well as an explanation of "how it
works." It appears to be based on a pair of counter-rotating weights.
The inventor is preparing to scale up his current models in order
to build an automobile-sized version. He claims that it would also
be good for "powering" boats. (The article concedes that it will
probably never replace the gas engine for either cars or boats.)

	To me this just seemed to be a vibrating weight that shook
whatever it was attached to, and in the presence of friction would
cause said body to skitter in a particular direction. I don't see
how it could work in a wheeled (low friction) vehicle, much less
a boat. Also, the article was worded (for the most part) as if this
thing was just a way of "making things move" (instead of using, say,
a transmission geared to the wheels or propeller). However, it also
says the device won't "replace the gas engine", implying that it
isn't powerful enough. So, is it supposed to be like a transmission
or like an engine?

	The article was careful to claim that this "uses gravity" and
is not a something-for-nothing proposition. It then goes on to suggest
that the device would be useful for levitating hovercraft! Shades
of the Dean Device!

	I'd like to consider myself open-minded, but this seems much
too bogus to be believed, as if a typical perpetual-motion crackpot
had learned what to say and what not to say in order not to have his
(old, tired) ideas immediately dismissed. Did anyone else see this
or similar articles? I believe it was "credited"(!) to the New York
Times News Service.

				Chris Scussel
				AT&T Bell Labs
				ihnp4!ihuxi!trough

smeier@ihu1h.UUCP (s. meier) (03/26/85)

I also read about this in the Chicago Tribune's (so-called) science
section.  For a moment I thought I had picked up the Enquirer by
mistake.  According to the vaguely worded article, the "device" is
driven by a gasoline engine, so the idea is that it is a "reactionless
drive" (No propellers in the water to cause friction). 
The article did not give enough details about the gizmo to
determine how it is supposed to work, but the illustrated device (two counter-
rotating weights) would certainly not get very far without some kind of
appropiately directed friction.  

fowler@uw-beaver (Rob Fowler) (03/26/85)

The U.S. Navy was investigating a drive mechanism of the sort described.
In particular, the problem is how to get a landing craft up a beach far
enough for men and vehicles to disembark rapidly with relatively dry
feet.  The other part of the problem is to get the boat back into the
water.

The drive mechanism is really simple:  A shaft that swings  a big weight
(actually a pair to cancel high order moments).  The axis of the shaft is
perpendicular to the long axis of the boat.  All you do is rotate this
sucker with a lot of enthusiasm.  When the weight is being swung downwards
the reaction partially lifts the boat from the shaft's bearings.  The
horizontal impulse of the following horizontal motion can move the
boat because it is working against the boat's inertia and REDUCED friction
between the beach and the boat's bottom.  When the weight is rising it
presses the bottom into the beach and the following horizontal impulse
works against increased friction so rearward motion is inhibited.  In 
short, this thing deliberately uses and enhances the "walking" tendancy
of any unbalanced rotating machinery.  The boat sort of hops out of the
water onto shore.  To back up all you need to do is reverse the direction
of rotation.

It has worked in prototypes.  The only problem (as you might guess) is that
it generates a hell of a lot of unpleasant vibration.  I don't know whether
anyone has ever used this mechanism for anything practical.

-- Rob Fowler (fowler@washington, uw-beaver!fowler)

john@x.UUCP (John Woods) (03/28/85)

> The "Tomorrow" section of the Chicago Tribune for Sunday, March 24 had
> an article about a vehicular "drive" that "uses" gravity. A diagram
> of the mechanism was included, as well as an explanation of "how it
> works." It appears to be based on a pair of counter-rotating weights.

Oh, yes, the way this one words is simple:  one of the weights is labelled
"6", and the other "9", so that the 9 weight is heavier, until it flips around
and becomes a 6...........
-- 
John Woods, Charles River Data Systems, Framingham MA, (617) 626-1101
...!decvax!frog!john, ...!mit-eddie!jfw, jfw%mit-ccc@MIT-XX.ARPA