A sealing apparatus is disclosed for inserting a probe into a pressure vessel having an elongated opening includes a pair of resiliently deformable seals opposingly disposed in sealing engagement with each other. A retainer is connected to the pressure vessel around the elongated opening and holds the pair of seals rigidly to the pressure vessel. A wedge is engageable with the pair of seals and carries the probe, for longitudinally translating the probe in pressure vessel

Trimarchi, Paul A.

English

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2O546
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(_|A_A-Case-L_W-IW965-|) PR_E INSERTION
APPARATUS WITH INFLATASLL SEAL P_ent
Application (i_ASa) 17 p CSCL 131
NO1-13732
Uncles
https://ntrs.nasa.gov/search.jsp?R=19910004419 2020-03-19T20:55:16+00:00Z
LEW-149_-I AWARDS ABSTRACT
PROBE INSERTION APPARATUS WITH INFLATABLE SEAL
The present invention relates generally to dynamic
seals and, more specifically, to one which employs
a pair of opposed, inflatable seals, between which
a probe can be inserted into a pressure chamber
without compromising internal pressure.
Referring to Figs. 1-3, a pair of inflatable seals
12 and 14 are mounted in opposing fashion in a
retainer 24 which is fixedly connected to a wall
18 of a pressure vessel over an elongated opening
16 provided therein. A wedge 34 slides
longitudinally between the opposed seals and
carries a probe 36 inside the pressure vessel.
The present invention provides a dynamic seal
which enables instrumentation to be inserted in a
wind tunnel without compromising internal
pressure.
Inventor:
Home Address:
ss#
Employer:
Initial Evaluator:
Serial No.:
Filed:
Paul A. Trimarchi
6126 Denise Avenue
North Ridgeville, OH 44039
NASA-Lewis Research Center
571,062
8/23/90
0
LEW-14965-1
PATENT
U.S. Patent Application
By
Paul A. Trimarchi
For
PROBE INSERTION APPARATUS WITH INFLATABLE SEAL
ILEW-14965-1 -2- PATENT
Title of the Invention
PROBE APPARATUS WITH INFLATABLE SEAL
Oriqin of the Invention
The invention described herein was made by an
employee of the United States Government and may
be manufactured and used by or for the government
for governmental purposes without payment of any
royalties thereon or therefore.
i0
Backqround of the Invention
Field of the Invention
15
The present invention relates generally to a
probe insertion apparatus and, more specifically,
to one which employs an inflatable seal as a
barrier surface between two chambers of differing
pressures.
2O
Description of the Related Art
During testing, a wind tunnel has an internal
pressure different from that of the external
pressure. In order to facilitate insertion of a
probe into the wind tunnel, and movement of the
LEW-14965-1 -3- PATENT
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probe within the wind tunnel after insertion, a
seal must be provided at an opening in the wind
tunnel so as to maintain the internal pressure.
It is known to provide a wind tunnel with a
lengthwise slot and a sliding face plate which
covers the slot. For a two foot long slot, the
conventional sliding face plate arrangement
requires about six feet in total length, since the
face plate must be four feet long to keep the slot
covered through full probe travel along the length
of the two foot slot. Full probe travel leaves up
to two feet of overhang of the face plate on
either side of the slot at any time. O-rings are
provided between the sliding face plate and the
outer wall of the wind tunnel to maintain pressure
integrity.
As an alternative to the sliding face plate,
all actuation hardware can be located inside a
pressure-tight check or bubble extension of the
pressure vessel and, while this method is suitable
for situations where linear traverse is the only
desired probe motion, it is much less practical
when other combinations of probe motion are
desired, such as, radial or rotary motion through
the tunnel wall. It is much less practical in
these cases because of the large additional volume
required.
O
LEW-14965-1 -4- PATENT
Summary of the Invention
5
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An object of the present invention is to
provide a seal capable of maintaining pressure
integrity of a pressure vessel while inserting and
moving a probe therethrough.
Another object of the present invention is to
provide an apparatus for inserting a probe into a
pressure vessel which requires relatively little
space.
Another object of the present invention is to
provide an apparatus for inserting a probe into a
pressure vessel which is relatively simple in
construction and cost effective to produce.
These and other features and advantages of
the present invention are met by providing a
sealing apparatus for inserting a probe into a
pressure vessel having an elongated opening,
including a pair of resiliently deformable seals
opposingly disposed in sealing engagement with
each other, retainer means connected to the
pressure vessel around the elongated opening for
holding the pair of seals rigidly to the pressure
vessel, and slider means engageable with the pair
of seals and carrying the probe, for
longitudinally translating the probe in the
pressure vessel.
LEW-14965-1 -5- PATENT
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Preferably, the slider means is a double-
ended wedge symmetrically shaped about a
longitudinal axis and being sharply pointed at the
opposite ends. A medial portion thereof carries
the probe, either fixedly or slidably by means of
a central, transverse bore.
These and other features and advantages of
the sealing apparatus for inserting a probe into a
pressure vessel according to the present invention
will become more apparent with reference to
following detailed description and drawings.
Brief Description of the Drawinqs
15
20
25
Fig. 1 is a top plan view showing a basic
component of the sealing apparatus according to
the present invention;
Fig. 2 is an enlarged vertical sectional view
taken along line II-II of Fig. i;
Fig. 3 is an enlarged vertical sectional view
taken along line III-III of Fig. i;
Fig. 4 is a perspective view of a probe and
sliding wedge used in the Fig. 1 embodiment of the
present invention;
Fig. 5 is a top plan view of a second
preferred embodiment of the present invention,
showing the basic structure of a sealing
apparatus;
LEW-14965-1 -6- PATENT
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Fig. 6 is an enlarged, vertical sectional
view taken along line VI-VI of Fig. 5;
Fig. 7 is a perspective view showing the
probe and wedge used in the embodiment of Fig. 5;
and
Fig. 8 is a perspective view, partially cut
away, showing a preferred drive mechanism
according to the present invention.
i0 Detailed Description of the Preferred Embodiments
15
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Referring now to Figs. 1-4, a sealing
apparatus for inserting a probe into a pressure
vessel, such as a wind tunnel, through an
elongated opening thereof is generally referred to
by the numeral I0. The apparatus includes a pair
of resiliently deformable seals 12 and 14
opposingly disposed in sealing engagement with
each other over the elongated opening 16 provided
in a sidewall 18 of the pressure vessel. The
seals are preferably inflatable through connectors
20 and 22 to a pressure which exceeds the internal
and external pressure of the pressure vessel. For
example, if the pressure within a wind tunnel is
30 psi, the seals 12 and 14 would be inflated to
about 50 psi. The connectors connect to a
pressurized source for supplying air, or other
fluid, to the seals.
LEW-14965-1 -7- PATENT
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i
The seals 12 and 14 are carried by a retainer
24 which includes two longitudinal U-shaped
sections 26 and 28 interconnected through end
plates 30 and 32. The retainer 24 is connected to
the sidewall 18 of the pressure vessel by any
suitable means, such as welding or by using
threaded fasteners. The retainer thus holds the
pair of seals rigidly to the pressure vessel.
A double-ended wedge 34 is longitudinally
slidable between the two seals 12 and 14. The
symmetrically curvilinear shape of the wedge 34,
with pointed opposite axial ends facilitates a
sealing engagement between the wedge and the seals
so that the integrity of the pressure within the
pressure vessel is maintained while the wedge 34
moves longitudinally between the two seals. As
shown in Fig. i, the seals 12 and 14 collapse
around the wedge 34 so as to sealingly engage the
wedge and prevent pressure equalization between
the outside and the inside of the pressure vessel.
As shown in Fig. 3, the wedge 34 carries a
probe 36 which extends into the pressure vessel
from a bottom of the wedge 34. A shaft 38 which
extends from the top of the wedge 34 can be
connected to an actuator for moving the wedge
longitudinally, thereby moving the probe
longitudinally within the pressure vessel. The
wedge 34 and shaft 38, as well as the probe 36,
4
LEW-14965-1 -8- PATENT
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may be hollow or may otherwise be provided with an
internal passageway to receive wiring from a
distal, sensing end 40 of the probe 36.
An important aspect of the present invention
is that the wedge 34 has a specifically designed
cross-sectional shape which provides a gentle
transition to enable the seals to conform to the
outer surface of the wedge without leakage. This
allows active positioning of the probe 38 within
the pressure vessel without compromising the
internal pressure. Probe actuation forces are
very low, even though the seals remain inflated
during probe movement, as long as the wedge/seal
interface is kept lubricated. The lubrication
also serves to prevent seal damage. Lubrication
may be effected by applying a lubricant to the
interface periodically. However, to avoid
frequent manual re-lubrication, a self-lubricating
system can be employed to bleed silicone grease
out of the wedge itself through openings 42, for
example. These openings may be provided as
outlets for a remotely located reservoir of
lubricant (not shown).
An alternative embodiment of the present
invention is illustrated in Figs. 5-7, in which
the retainer 24 slidably carries the wedge 34,
which is incorporated into a carriage 44 having an
upper guide plate 46 and a lower guide plate 48
" Q
LEW-14965-1 -9- PATENT
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between which the wedge 34 is positioned.
In the embodiment of Figs. 5-7, the carriage
44 is provided with a central bore 50 in which a
probe 52 is slidably disposed. Thus, the probe 52
is longitudinally movable'within the pressure
vessel, and also transversely movable through the
carriage, as indicating by the directional arrows
in Fig. 7. A sheet of sealing material 54 is
provided on top of the guide plate 46, and is
sandwiched between the guide plate 44 and a
retainer plate 56 so as to help prevent leakage of
pressure through the bore 50.
As a slight modification, the embodiment of
Figs. 5-7 involves a wider elongated opening, into
which a mounting plate 58 is secured by
conventional means, such as welding, threaded
fasteners, etc. Then, the retainer 24 is mounted
on the mounting plate 58 also by using
conventional fastening means. The mounting plate
58 has an elongated openin_ provided centrally
therein, which corresponds to the opening 16 of
the first embodiment.
Fig. 8 illustrates a drive mechanism which is
capable of moving the probe longitudinally along
the length of the elongated opening. A pair of
support plates 60 and 62 are rigidly connected to
the mounting plate 58 at opposite axial ends
thereof. A pair of guide rails 64 and 66 extend
LEW-14965-1 -i0- PATENT
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between the support plate 60 and 62 and provide
guides for the carriage 68 which is provided with
a pair of support blocks 70 and 72 in which the
guide rails 64 and 66 are slidably mounted.
A ball nut 74 is mounted to the upper guide
plate 76 of the carriage 68. The ball nut has a
threaded bore 78 which threadedly engages a
rotatable ball screw 80 which is journaled in the
support plates 60 and 62 for rotation in either
direction. Rotational movement is imparted in the
ball screw by an electric drive motor 82 working
through a gear box 84. Details of the gear box
and drive motor, and their connections to the ball
screw are not shown herein since they are all of
conventional design and well known to those of
ordinary skill in the art, as well as commercially
available. When the ball screw 80 is caused to
rotate by the drive motor 82 working through the
gear box 84, the guide rails 64 and 66 prevent the
carriage 68 from rotating with the ball screw 80.
Therefore, the carriage 68 moves longitudinally
along the guide rails 64 and 66 in either
direction.
The carriage 68 also has a central bore 86
into which a probe is slidably mounted. The probe
(not shown) can thus be moved transversely into
and out of the pressure vessel, as well as axially
along the length of the pressure vessel.
LEW-14965-1 -ii- PATENT
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Transverse movement of the probe can be done
mechanically or manually simply by pushing the
probe further into the pressure vessel.
The shape of the wedge 34 in all embodiments
of the present invention is preferably smoothly
curved and completely symmetric. The shape
somewhat resembles a tear drop and is preferably
curvilinear to provide a smooth transition between
the pointed ends.
For high temperature applications, both an
inlet and outlet line may be added to each seal to
allow pressurized coolant to circulate, thereby
maintaining seal temperature below the seals
melting point.
Numerous modifications and adaptations of the
present invention will be apparent to those so
skilled in the art and thus, it is intended by the
following claims to cover all such modifications
and adaptations which fall within the true spirit
and scope of the invention.
What is claimed is:
LEW-14965-1 PATENT
PROBE INSERTION APPARATUS WITH INFLATABLE SEAL
Abstract of the Disclosure
1
A sealing apparatus_for inserting a probe
into a pressure vessel having an elongated opening
includes a pair of resiliently deformable seals
opposingly disposed in sealing engagement with
each other. A retainer is connected to the
pressure vessel around the elongated opening and
holds the pair of seals rigidly to the pressure
vessel. A wedge is engageable with the pair of
seals and carries the probe, for longitudinally
translating the probe in pressure vessel.
FIG. I
:50-
m--I rr--I 18
12
24
18
16
FIG. 4
E
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r/
I/
z/
,//
//
//
/./
r/
//
z/
F/
34
/f _24
_36
38
34
36
2
FIG. 5
/
/
!
f
56
i 54
FI 44
24
50
FIG. 7 44 _J_/_-._48
FIG. 8
62
82
0
66
60
I
/
58


Probe insertion apparatus with inflatable seal

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