An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)

wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)



Darned good question, and I couldn't find a trace of the inventor either.

Maybe they were first produced by a company in Oldham, England?

FWIW, now that you got me hooked, does the design minimize angular
rotation "distortion" when used on offset but parallel shafts, similar
to the way a pair of crossed (i.e. offset 90 degrees to each other.)
universal joints will?

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Dear shoppa:

wrote in message
ups.com...
An "Oldham Coupler" is way to transfer torque between two
parallel but
not-quite-collinear shafts.

Don't concentrate on the words that are not necessary in your
search, or use alternatives. Requiring both words oldham and
mechanism, I get this hit:
URL:http://kmoddl.library.cornell.edu/model.php?m=230
.... which points to Oldham, John
URL:http://kmoddl.library.cornell.edu/bi...dham/index.php

David A. Smith

Jeff Wisnia wrote:
wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)



Darned good question, and I couldn't find a trace of the inventor either.

Maybe they were first produced by a company in Oldham, England?

FWIW, now that you got me hooked, does the design minimize angular
rotation "distortion" when used on offset but parallel shafts, similar
to the way a pair of crossed (i.e. offset 90 degrees to each other.)
universal joints will?

Jeff

If you ignore such inconveniences as backlash, flex and friction then
the Oldham coupling should have no angular rotation distortion --
because regardless of the linear offset the middle disk's angle will be
fixed to both end disks by the slot and groove arrangement.

Of course the same is true for crossed U-joints; the question would be
which one does better in practice?

--
-------------------------------------------
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Google searches turn up the device's inclusion in R-390A radios and

Reading this just makes me feel old cause I remember when the R-390A
was the Navy's premier state-of-the-art SSB receiver, and that was in
the SIXTIES!!!

wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)

Knight's "American Mechanical Dictionary" of 1872 says that it was
invented by Oldham...So it goes back a ways.

Tom

N:dlzc D:aol T:com (dlzc) wrote:
Dear shoppa:

wrote in message
ups.com...

An "Oldham Coupler" is way to transfer torque between two
parallel but
not-quite-collinear shafts.


Don't concentrate on the words that are not necessary in your
search, or use alternatives. Requiring both words oldham and
mechanism, I get this hit:
URL:http://kmoddl.library.cornell.edu/model.php?m=230
... which points to Oldham, John
URL:http://kmoddl.library.cornell.edu/bi...dham/index.php

David A. Smith



Bravo David!

You da man!

Jeff (Who refuses to admit how long I tried to find the answer earlier
today...)

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Hey Tom,

Do you have a copy of Knight's Dictionary? I have one too. Three volumes.
A great set of books. I bought mine from an antique store in Wales when I
was in graduate school in the 70's. Great fun to look through. Whoever had
my copy originally was involved in the shipping industry. He made a lot of
pencil notes in the margins for listings related to steamship design.

This is my favorite plate:
http://www.geocities.com/viewptmd/GatlingGun.tif/ listed under "Battery
Gun".

--
Bob (Chief Pilot, White Knuckle Airways)


"Tom" wrote in message
...
wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)

Knight's "American Mechanical Dictionary" of 1872 says that it was
invented by Oldham...So it goes back a ways.

Tom

Bob Chilcoat wrote:

Hey Tom,

Do you have a copy of Knight's Dictionary? I have one too. Three volumes.
A great set of books. I bought mine from an antique store in Wales when I
was in graduate school in the 70's. Great fun to look through. Whoever had
my copy originally was involved in the shipping industry. He made a lot of
pencil notes in the margins for listings related to steamship design.

This is my favorite plate:
http://www.geocities.com/viewptmd/GatlingGun.tif/ listed under "Battery
Gun".

--
Bob (Chief Pilot, White Knuckle Airways)

"Tom" wrote in message
...
wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)

Knight's "American Mechanical Dictionary" of 1872 says that it was
invented by Oldham...So it goes back a ways.

Tom

That's a real classic!
Couldn't get your link to work, so I put a scan he
http://shopswarf.orcon.net.nz/gatling.jpg

Tom

My link was screwed up somehow. I don't have time to fix it tonight. Your
scan is better than mine, anyway. Mine came out too dark.

I always thought this pic looked like it was of an early Al Qaeda training
site. Where did you get your set of Knight's?

--
Bob (Chief Pilot, White Knuckle Airways)


"Tom" wrote in message
...
Bob Chilcoat wrote:

Hey Tom,

Do you have a copy of Knight's Dictionary? I have one too. Three
volumes.
A great set of books. I bought mine from an antique store in Wales when
I
was in graduate school in the 70's. Great fun to look through. Whoever
had
my copy originally was involved in the shipping industry. He made a lot
of
pencil notes in the margins for listings related to steamship design.

This is my favorite plate:
http://www.geocities.com/viewptmd/GatlingGun.tif/ listed under "Battery
Gun".

--
Bob (Chief Pilot, White Knuckle Airways)

"Tom" wrote in message
...
wrote:

An "Oldham Coupler" is way to transfer torque between two parallel
but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined
to
the first two by tongue and groove. The tongue/groove on one side
is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much
more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim.
(who
otherwise wonders who takes care of the caretaker's daughter while
the
caretaker's busy taking care.)

Knight's "American Mechanical Dictionary" of 1872 says that it was
invented by Oldham...So it goes back a ways.

Tom

That's a real classic!
Couldn't get your link to work, so I put a scan he
http://shopswarf.orcon.net.nz/gatling.jpg

Tom

Bob Chilcoat wrote:

My link was screwed up somehow. I don't have time to fix it tonight. Your
scan is better than mine, anyway. Mine came out too dark.

I always thought this pic looked like it was of an early Al Qaeda training
site. Where did you get your set of Knight's?

--
Bob (Chief Pilot, White Knuckle Airways)

"Tom" wrote in message
...
Bob Chilcoat wrote:

Hey Tom,

Do you have a copy of Knight's Dictionary? I have one too. Three
volumes.
A great set of books. I bought mine from an antique store in Wales when
I
was in graduate school in the 70's. Great fun to look through. Whoever
had
my copy originally was involved in the shipping industry. He made a lot
of
pencil notes in the margins for listings related to steamship design.

This is my favorite plate:
http://www.geocities.com/viewptmd/GatlingGun.tif/ listed under "Battery
Gun".

--
Bob (Chief Pilot, White Knuckle Airways)

"Tom" wrote in message
...
wrote:

An "Oldham Coupler" is way to transfer torque between two parallel
but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined
to
the first two by tongue and groove. The tongue/groove on one side
is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much
more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim.
(who
otherwise wonders who takes care of the caretaker's daughter while
the
caretaker's busy taking care.)

Knight's "American Mechanical Dictionary" of 1872 says that it was
invented by Oldham...So it goes back a ways.

Tom

That's a real classic!
Couldn't get your link to work, so I put a scan he
http://shopswarf.orcon.net.nz/gatling.jpg

Tom

Lions book sale, $5 :-)

Tom

On 5 Jun 2005 08:17:25 -0700, wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)



John Oldham - Ireland, early 1800s. Egraver, toolmaker, and general
genius.

wrote:

An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)

Those are often used in high voltage to shaft adapters - fiber length to
a steel through to knob. Seems I have some - stainless...
The Web only contains those who someone already thought of or who is remembered....
Maybe this is your shot to generate a web page.

Martin

--
Martin Eastburn
@ home at Lion's Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

LP posted:

"Reading this just makes me feel old cause I remember when the R-390A
was the Navy's premier state-of-the-art SSB receiver, and that was in
the SIXTIES!!!"

If being an R-390A user makes you feel old, having been a member of
design team of the T-368 transmitter that accompanied the R-390A in the
Army's GRC TTY communications vans, then I must be ANCIENT! ! ! ! !

Actually, the R-390A is still a very competitive receiver commanding
very high prices on eBay, perhaps second only to the Collins 75A4
(whose design is heavy based on certain sections of the R-390A). At the
time (circa 1960) many firms tried to duplicate the R-390A's variable
frequency local oscillator but failed because no one could figure out a
production alignment methodology that would produce the same frequency
linearity as did the Collins produced LO unit. (At least at B&W we
couldn't.) This involved the precise bending of a capacitive loading
finger strip that paralleled a rotating, variable inductance coil and
compensated for a small amount of tracking error in the coil's
windings.

The old 'boat anchor' receivers still hold an advantage over most of
the current generation of solid state units -- That is, when they break
you can fix them yourself! :-)

IIRC, two versions of the R-390A were produced, one with a conventional
tuning dial and the other with a geneva mechanism type counter showing
the tuning setting but not the frequency. The receivers were produced
by a number of firms, but so far as I know all of the LOs in them were
manufactured by Collins Radio.

Ah, memories....

Harry C.

http://kmoddl.library.cornell.edu/bi...dham/index.php


wrote:
An "Oldham Coupler" is way to transfer torque between two parallel but
not-quite-collinear shafts. It has three disks, one coupled to the
input, one coupled to the output, and a middle disk that is joined to
the first two by tongue and groove. The tongue/groove on one side is
perpendicular to the tongue/groove on the other. Often springs are
used to reduce backlash of the mechanism. The coupler is much more
compact than, say, two universal joints. But: who was Mr. Oldham?
Google searches turn up the device's inclusion in R-390A radios and
astronomical instruments, but nothing about its inventor. Tim. (who
otherwise wonders who takes care of the caretaker's daughter while the
caretaker's busy taking care.)