No Euro hitch usable in US

[Larry C Leung]

Purely from an engineering standpoint, the hammering effect is what is
called impulse of short time duration. Its what we try to avoid in all
machines and living things, i.e. airbags were invented to prevent the
short duration impulse of your head and chest hitting the steering wheel
in a crash. The airbag extends the time of the collision, limiting the
force needed to stop your body. Without the airbag (and/or seatbelt,
which in the stretching of the fabric by design, serves the same purpose)
your body still gets stopped, just MUCH more suddenly. The decrease in
force by the added time of the airbag is what helps you live. 

the formula J = F x t, where:	J is the Impulse (the same ANYTIME there is
an acceleration)
			F is force
			t is the time of the acceleration

Now with regards to the hitch, every bump, acceleration, braking, etc
became an impact force to alter the motion of the trailer. With a proper
hitch ball, the force just is simply the force needed to accelerate the
trailer, the time of the acceleration is exactly the same as the
acceleration of the tow car and trailer. With an undersized ball, every
change became an impact, so for a brief moment, the tow car accelerated,
but the trailer DID NOT, until the undersized ball impacted the socket in
the tongue of the trailer. NOW we have a High Force over a short time
(impact!) needed to accelerate the trailer appropriately. 

Result, bent bumper (fortunately, the bumper bending extended the life of
the hitch and ball), and luckily, not a lost trailer. 

the Physics Teacher



On Tue, 16 Oct 2001 21:19:45 -0400 Kneale Brownson
<knotnook at traverse.com> writes:
>At 07:29 PM 10/16/2001 -0400, Larry C Leung wrote:
>
>>Would you trust 2000 lbs to a 0.8 mm diameter difference. It's a 
>matter
>>of play, interference fit and impact. You MUST use the proper towing
>>ball, or the ball/mount joint will most likely fail from impact 
>loading.
>
>I can support Larry's point sort-of with anecdotal evidence:  The guy 
>who 
>sold me my Bridgeport mill hauled it to me a couple hundred miles, 
>using my 
>trailer with a 2" hitch.  I didn't know it (wasn't there when he 
>picked up 
>the trailer), but his pickmeup had a 1 7/8 ball in the hitch.  The 
>trailer 
>and mill thump-thumped his bumper/hitch till it was bent way out of 
>line.  He didn't say anything, but his buddy and riding companion told 
>me 
>the bumper was straight and level before the trip.