Bridal Straps Married

atonal@telusplanet.net atonal@telusplanet.net
Wed, 29 Sep 1999 07:19:53 -0600


The excellent article in question was by Jim Ellis, RPT in the 
December 1997 Journal "Bridle Strap Function" pp 17-20. This 
article was written partly to rebut the assertation I made in an 
article in the August 1997 Journal that the sole function of bridle 
straps (in modern pianos) was to keep the jack from slipping under 
the hammer butt felt and becoming lodged when the action was 
removed from the piano. Jim Ellis proved conclusively using a fairly 
sophisticated measuring apparatus that hammer return time is 
greatly improved with bridle straps engaged verses disengaged. 

This follows from the 'Father of the Bridle Strap" Robert Wornum, 
who patented the 'tape check action' for a vertical piano in 1826. 
There is no hammer return spring in his action. the strap provided 
the physical return force, after hammer rebound, of course. (Some 
of this I knew, but this is paraphrased from Jims article) 
One of the main thrusts of Jims article is the current PTG teaching, 
through PACE and through the written exam questions stresses 
the 'correct' answer to bridle strap function is what I originally 
stated, and ther is no effect on hammer return. Through a fairly 
elaborate electronic measuring apparatus, Jim got differences in 
hammer return time of 35 to 63 milliseconds on various pianos with 
the bridle strap disengaged. Clearly this makes hammer repetition 
a big part of the strap's function. Time to revise the teaching!!

As for procedure on installing them, check out my article online at 
http://www.telusplanet.net/public/atonal/bstrap.html 

If the first image loads over the text, hit the 'reload' button on your 
browser.

> Dave wrote:
>  What the bridal strap is there for.  >
> 
> Besides helping to keep the jacks from not dropping down far enough to make
> action installation back into the piano difficult they also help in hammer
> return as mentioned in a Journal article.  I can't remember the author
> though I do remember him winning an award for said article at the RI
> National Convention.  Excellent article.
> Sincerely,
> Doug Mahard, Associate Member
> 

Regards, 


Rob Kiddell RPT
Atonal Piano Service
http://www.telusplanet.net/public/atonal/


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