changing the pitch of the reed with a "tooth" bar

[Deleted member 48]

Has anyone ever tried to change the pitch of an accordion or concertina reed by using a down pressed bar of teeth, making the pitch a semitone higher?
In reading the 1829 Charles Wheatstone patent, he shows in the technical drawings one of his inventions:
a sort of metal bar with little teeth that can shorten the vibrating part of the reed, thus making the reed to sound a semitone higher.

Its described in this patent, a pdf, page 10 has the technical drawings, see figures 24 and 25. On page 5 he starts to describe the possible ways to have semitones (separate extra semitone reeds, or the tooth bar system on the naturals)
Improvements in the Construction of Wind Musical Instruments (1829)
http://www.concertina.com/patents/

He says you can use it to save reeds inside a concertina or symphonium, and make one reed sound its natural or his sharpened pitch.
Here is a photo of 2 instruments having those inside bars that can be pressed down via a simple button:
http://www.concertinamuseum.com/Images/C15/C15001-002i.jpg

info on the instrument
http://www.concertinamuseum.com/C15001-002.htm

I have a few questions.
Was there once an accordion, concertina or mouth harmonica maker who used this system and made such instruments?
Would it be useful to do this (eg in fast musical passages), because I suppose the entire bar goes down on the reeds if the button is pressed?
Could those little metal teeth do damage to the reeds, when touching or making scratches ?

 

[Glenn]

There are many patents which although sounding clever and useful have a huge raft of technical issues that have to be solved first.
A patent does not have to be commercially viable either.
I suspect that the Wheatstone patent has some serious technical issues that makes its commercially viable implementation difficult.
That is not to say that many years later a new solution to an old problem can be used but by then at least the patent is merely prior-art history.

 

[Deleted member 48]

This idea might of little metal teeth shortening the vibrating parts of the reed(s) could be used, if not damaging (perhaps steel reeds are hard enough for these tiny metal teeth), could be used in instruments using 1 single reed plate, having all the reeds mounted on 1 plate (some mouth harmonicas, symphoniums, melodicas, or even bayan style reed plates).
Commercial applications to me dont really matter, maybe this system could be used to make new free reed types, and diminish the number of reeds inside.

This is also interesting to read: the gliding reed principle
http://www.d-and-d.com/contributions/tina-history.html

on 18 August 1871, he and J M A Stroh jointly patented a New Musical Instrument, a sort of gliding-reed symphonium, in which a single reed tongue is changed in length to produce changes in pitch via a complex mechanism contained within a highly modified symphonium. The gliding reed principle is also used in the Wheatstone prototype gliding reed concertina in the C M Collection, item C509, in which the single reeds vibrating length is adjusted by a pair of variable pinch-rollers (8).

Id be interested to see some online photos of such an instrument, to have a look and see if it can be used or not.
The fact that they still talk about it in 1872, many years later after 1829, maybe it isnt a bad idea.

1 or 2 metal bars inside free reed instruments wouldnt be expensive to build in.

Off course in mouth harmonicas the chromatic slide made the diatonic harps chromatic, but you still need 2 sets of reed plates and 2 different reeds.
This Wheatstone system makes 1 reed sounding 2 notes, the natural and the sharpened by a semitone.

When I have a look at the photos it looks like only a small part of the reed is shortened by the bar.

 

[Nuuksu]

It sounds interesting but I think, it wouldn't work very well because its mechanics need to be very well made, very precise and very well maintained. I think we all know how frustraiting can actually be bass or treble keyboard mechanics if don't work very well. Even smallest amount of too weak pressure can lead to strange bussing sound and little stronger pressure than needed may damage red or it just doesn't respond very well.

 

[TomBR]

The Regal reed organ seems to be often forgotten in the history of free reed instruments. Its reeds were tuned by adjusting a bar that shortened the tongue as above.
Wikipedia is a useful summary and link to the sources
http://en.wikipedia.org/wiki/Regal_(instrument)

 

[Deleted member 48]

Do you know an online photo of a regal with a bar that shortens the tongue?
I didnt know they made regals having this system in the renaissance or baroque period.

Doesnt the regal have another type of reeds? Beating reeds?
I think the regal is not a free reed instrument like the accordion or harmonium. It uses a different type of reed.

Heres described the difference between free reeds and beating reeds:
http://www.patmissin.com/history/whatis.html

 

[TomBR]

I found a good picture the other day, but now I cant find it.
Very small pictures on this page
http://www.tastenklang.de/Orgeln_Positive/orgeln_body_en.html
Brass tongues over wooden troughs.

I think regal reeds are a bit of a hybrid. Theyre not free in the sense that they swing freely without making contact with the reed frame, but they are free in the sense that their pitch is governed by their length, mass and stiffness, not by a vibrating air column.

Renaissance musical sense does seem to have liked buzzing sounds that we now dont care for, eg bray pins on a harp, hence the regal with its reeds buzzing against the frame went out of fashion when tastes changed.