I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. This is the Mahr unit. I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. I think it
was Jon Elson who mentioned these patents.

What I have found is US Patents 4,023,413 and 5,022,264 from Wyler AG is
Switzerland, a competitor. This is capacitive, not inductive like the
Talyval unit.

Anyway, does anyone know the patent numbers, or the inventors name? Or
an article or book reference? I have found only a number of truncated
references or descriptions, but nothing with real meat on it.

Thanks,

Joe Gwinn

Joseph Gwinn writes:

Anyway, does anyone know the patent numbers, or the inventors name?

Search assignees for "Taylor Hobson"?

On Apr 3, 12:03*am, Joseph Gwinn wrote:
I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. *This is the Mahr unit. *I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. *I think it
was Jon Elson who mentioned these patents.

What I have found is US Patents 4,023,413 and 5,022,264 from Wyler AG is
Switzerland, a competitor. *This is capacitive, not inductive like the
Talyval unit.

Anyway, does anyone know the patent numbers, or the inventors name? *Or
an article or book reference? *I have found only a number of truncated
references or descriptions, but nothing with real meat on it.

Thanks,

Joe Gwinn

On Apr 3, 12:03*am, Joseph Gwinn wrote:
I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. *This is the Mahr unit. *I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. *I think it
was Jon Elson who mentioned these patents.

What I have found is US Patents 4,023,413 and 5,022,264 from Wyler AG is
Switzerland, a competitor. *This is capacitive, not inductive like the
Talyval unit.

Anyway, does anyone know the patent numbers, or the inventors name? *Or
an article or book reference? *I have found only a number of truncated
references or descriptions, but nothing with real meat on it.

Thanks,

Joe Gwinn

Google patents goes back more than 100 years. Go to google search
to more, even more, and the light bulb icon. You can search by words,
date, names or number. It is free and you can print it out. OCR gets
a few titles garbled but it is quite good. Charlie

In article
,
Charles Lessig wrote:

On Apr 3, 12:03*am, Joseph Gwinn wrote:
I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance" (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. *This is the Mahr unit. *I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. *I think it
was Jon Elson who mentioned these patents.

What I have found is US Patents 4,023,413 and 5,022,264 from Wyler AG is
Switzerland, a competitor. *This is capacitive, not inductive like the
Talyval unit.

Anyway, does anyone know the patent numbers, or the inventors name? *Or
an article or book reference? *I have found only a number of truncated
references or descriptions, but nothing with real meat on it.

Thanks,

Joe Gwinn

Google patents goes back more than 100 years. Go to google search
to more, even more, and the light bulb icon. You can search by words,
date, names or number. It is free and you can print it out. OCR gets
a few titles garbled but it is quite good. Charlie

I have used Google Patents before, but had a lot of trouble with
OCR-induced garbles defeating search. But it's worth a try, as the
USPTO search only goes back to 1976.

I did search on "taylor hobson", "rank", "federal products", "mahr", and
so on both as patent assignees and on Google. Complicated corporate
history here.

The only possible inventor name I've found so far is "Richard E Reason"
who is named in a book on instrumentation as the brain behind other
Taylor Hobson mechanical sensors at that time. But no hits at the USPTO.

One of those books also cited a book in German as the reference on the
Taylval. I've requested the book, and will see if my schoolboy German
is up to the task. Actually, the references the book cites may be
sufficient, and many will be in English.


Joe Gwinn

Joseph Gwinn wrote:
I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. This is the Mahr unit. I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. I think it
was Jon Elson who mentioned these patents.

Only thing I know is that the original Talyvel was made in the early
1960's, to guess from the appearace of the unit.

But, the technology is not real complex. You need a pair of opposed,
well-matched proximity sensors that are not subject to differential
drift. You suspend a very light platform from insanely tiny wires. I
suspect it has an aluminum vane that hangs between magnets for damping.
The display box reads the difference between the two sensors. Now that
I've seen the inside of one, I'll bet I could make one myself that would
actually work. Of course, making it work as WELL as the Talyvel, even
under various slants on the cross-axis, is not so easy.

Jon

In article ,
Jon Elson wrote:

Joseph Gwinn wrote:
I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. This is the Mahr unit. I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. I think it
was Jon Elson who mentioned these patents.

Only thing I know is that the original Talyvel was made in the early
1960's, to guess from the appearace of the unit.

But, the technology is not real complex. You need a pair of opposed,
well-matched proximity sensors that are not subject to differential
drift. You suspend a very light platform from insanely tiny wires. I
suspect it has an aluminum vane that hangs between magnets for damping.
The display box reads the difference between the two sensors. Now that
I've seen the inside of one, I'll bet I could make one myself that would
actually work. Of course, making it work as WELL as the Talyvel, even
under various slants on the cross-axis, is not so easy.

I gather that the Talyvel Clinometers went through a number of
generations, and the latest generation was built differently than you
describe, although it is still pretty simple. The current generation is
numbered 5, it appears.

Google for "The Electronic Level * Device of Many Uses" by GEORGE J.
SCHUETZ, Director of Precision Gages, Mahr Federal Inc., Providence,
Rhode Island. The drawing he gives is what is in the textbooks as the
Talyvel.
http://www.deterco.com/tech_info/MAH...Level%20System
%20Articles/Levels%20Applications.pdf

The current Talyvel5 from Mahr has a different diagram, but this may be
an oversimplification of Schuetz's diagram: search for "talyvel_5.pdf"
http://www.imep.com.tr/urunler/urun/urun_brosur/talyvel_5.pdf.

Research continues.

Joe Gwinn

"Jon Elson" wrote in message
...
Joseph Gwinn wrote:
I'm interested in the electronic levels mentioned in the thread "Surface
plate maintenance (19 March 2009 et seq), specifically the Talyval from
Taylor Hobson. This is the Mahr unit. I've been trying to find the
original patents (long expired), but have struck out, probably because
the US Patent Office only has searchable text back to 1976. I think it
was Jon Elson who mentioned these patents.

Only thing I know is that the original Talyvel was made in the early
1960's, to guess from the appearace of the unit.

But, the technology is not real complex. You need a pair of opposed,
well-matched proximity sensors that are not subject to differential drift.
You suspend a very light platform from insanely tiny wires. I suspect it
has an aluminum vane that hangs between magnets for damping.
The display box reads the difference between the two sensors. Now that
I've seen the inside of one, I'll bet I could make one myself that would
actually work. Of course, making it work as WELL as the Talyvel, even
under various slants on the cross-axis, is not so easy.

Jon


the same basic principle is used in aircraft gyro heading instruments to
detect angular deflection and provide feedback for flight directors and
autopilots.


John