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Hi, Sean
I'm shaking my head at myself - my previous email
comments refer to my original 1984 patent CA 1171601, not so much the 1992
CA 1209632 which was the subject of your query - I should have looked more
closely at the numbers. That original 1984 'principle' patent is the one from
which my later 1992 patent was derived as was Humphrey's 2002 patent. The latter
two depend exclusively on the 1984 patent for the rotary joint itself - but
don't claim any functional part of the 1984 patent since it is, by definition,
prior art.(BTW, for the record, my original 1984 patent was applied
for in 1982 - years before Humphrey came to work for me at Can-Dive
Services Ltd. and later at Hard Suits.) Both the 1992 and the 2002 patents claim
only the very specific mods to the 1984 patent, but any layman looking at
these patents would likely assume it was for the whole 'joint'.
After all this boring background, the answer to
your question is'yes' you are correct in assuming that the minor 'flex' was not
considered in designing the limbs envelope of
movement.
----- Original Message -----
Sent: Saturday, October 30, 2010 11:37
PM
Subject: Re: [PSUBS-MAILIST] rotary ADS
joint question
Thanks for the reply, and sorry for bringing up a touchy
subject. I think you answered my actual question, but just to be sure -
My understanding is that the flex was never considered when designing the
joint range of motion, and the observed effect is mentioned in the patent out
of interest only. Thus, the required joint ranges of motion (human
kinetic model) are accommodated solely by (theoretically) axially rigid
joints?
-Sean
On 30/10/2010 10:24 PM, Phil Nuytten wrote:
Hi, Sean:
I can understand your confusion since the
language in this particular patent is not as clear as it should be . . the
degree of axial movement cited - a couple of degrees - is the allowable tilt
of the oil reservoir piston without binding. It has nothing to do with the
'anti-tilt' bearing described in Humphrey's subsequent patent CA 2485908.
The anti-tilt mechanism was developed by my company, (Hard Suits Inc.)
around the same time as my CA 1209632 patent - that patent describes
the basic principle of the rotary joint but purposely omitted the
'anti-tilt' feature and an addition feature which was in use at that time
called the 'fail-safe' ring.
Although the Humprey patent appears to cover an
entire rotary joint - it does not. The joint shown in the Humphrey is from
my original patent, but with the addition of the 'anti-tilt' feature and the
'fail-safe' ring. There are only two claims in the Humphrey patent -
the 'anti-tilt and the 'fail-safe' - the rest is prior art (my prior art).
The short version is that my original patent lapsed and the owners of the
company (which was sold and re-named several times after it was acquired
from me and the other shareholders by a hostile take-over bid from a
Texas company in 1996) very much wanted to continue to claim 'exclusive
patented technology' even though that was no longer the case. Humphrey
was my employee from 1985 to late 2001 and, unbeknownst to me, cut
a deal with Oceanworks (the most recent descendant of the original
Hard Suits Inc.) to 'patent' these two features in his name - but
assigned to Oceanworks,(the two features that were not in my original
patent.)
He is no longer in my employ.
The few degrees of axial movement possible in
the oil make-up section amount to about 15 degrees in a five bearing limb -
significant - but nothing like the 90 degrees of normal movement - it is
made possible by 'rocking' the piston when the reservoir is partially
depleted - not usually used and not claimed in either patent.
This pretty sketchy, but I can't
go into further detail - except to say that I am currently the sole
owner of Hard Suits Inc.
Original Message -----
Sent: Saturday, October 30, 2010
12:31 PM
Subject: [PSUBS-MAILIST] rotary ADS
joint question
Perhaps best directed at Phil, but posted to the list in
case anyone is interested:
I was looking at some of the old ADS
suit joint patents, and I noticed that the old Nuytten patent (CA
1296032) describes a degree of freedom in axial alignment of 1.5
- 3 degrees per joint. By inspection, it appears that this is the
result of the movement of lower member 2 in this patent, although I could
be mistaken. In any case, this permissible misalignment is touted as
a design advantage in the patent, although it is not clear whether this
allowable flex is by design intent, or merely an unintended consequence of
the assembly. In the subsequent Humphrey patent (CA
2485908), this degree of freedom is characterized as undesirable,
and indeed the joint described in this patent specifically attempts to
eliminate it and establish axial rigidity, in an attempt to prevent any
bending load on the joint from causing seal leakage. Intuitively
this makes some sense, although the Nuytten patent describes a cumulative
flexing ability of 18 degrees over a seven-joint conduit; this is not
insignificant. I presume that this difference would need to be
accommodated by adjusting the wedge angles and/or rotary limits of each
joint such that the necessary range of motion of the operator is not
impacted. I'm not entirely sure what I'm asking here - other than to
get some idea of whether flex is an important design objective, or whether
it is simply the result of holding looser assembly tolerances than a
design using fully rigid joints which relies upon joint rotation
exclusively?
-Sean
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