Connection apparatus

An improved apparatus for connecting first and second conduits, which may be capillary columns, having first and second bores, respectively, to provide communication between the first and second bores for high temperature operation over wide variations in temperature. A monolithic fused quartz seating element is removably insertable into a seating chamber of a base that may be comprised of steel or other metal. The monolithic fused quartz seating element may be cylindrical and have frustoconical surfaces defining first and second receiving formations. First and second slidable followers biased by first and second quartz springs apply pressure against first and second ferrules to seal between the first and second receiving formations, and the first and second conduits, respectively.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an improved apparatus for effecting 
gas-tight communications between first and second members having bores for 
the passage of fluid. More particularly, the present invention relates to 
an improved connection having a monolithic sealing element with distinct 
ferrule forming and ferrule biasing engagement surfaces for connecting 
first and second tubular members. 
2. Description of the Background 
There are numerous types of analytical instrumentation used in 
laboratories, chemical and refining plants and the like, which require 
high temperature connection of a first tubular member through which is 
transported a fluid, such as a gas, to a second tubular member. 
Exemplary examples of such connections are shown in U.S. Pat. No. 4,991,883 
('883) and U.S. Pat. No. 5,163,722 ('722) to R. D. Worden, which are 
incorporated herein by reference. The connection shown in the '883 patent 
provides a fluid tight connection for operation over wide temperature 
ranges and high temperatures that subject the mechanical components of 
this connection to considerable expansion and contraction. In a preferred 
embodiment of the invention disclosed in the '883 patent, a fused quartz 
spring is used as a biasing element to maintain a constant biasing force 
on a sealing ferrule. The sealing ferrule seals between an inner conduit 
containing a fluid and an outer sealing surface. 
On occasion, it is desirable to use a fluid carrying conduit that is 
undersize with respect to the sealing ferrule. While a quartz spring 
provides ample force to maintain sealing pressure during wide temperature 
variations, such a spring may not be strong enough to make an initial seal 
with an undersize conduit. The 722' patent shows an apparatus that creates 
an initial seal by applying force to a follower. After forming an initial 
seal, pressure is maintained against the follower by the quartz spring. 
A continuing problem with high temperature connectors of the type under 
consideration is the high cost and fragile nature of components often 
associated with such connectors. The connectors operate at high 
temperatures in excess of 400.degree. C. They also experience wide 
temperature swings in excess of 600.degree. C. Additionally, they must be 
chemically inert to be of practical value. Thus, fused quartz is often the 
only practical material of which the base portion of these connectors can 
be formed. However, fused quartz is relatively fragile as compared with 
steel, for instance. Moreover, fused quartz structures tend to be 
expensive. While fused quartz is generally impervious to most materials, 
at the temperatures of operation the fused quartz exposed surfaces may 
become coated or fused with other materials, e.g., the components passing 
through the tubular member. When damage of any type occurs, the relatively 
expensive connector must be replaced. It is frequently necessary to heat 
the quartz components thereby requiring substantial time and heat energy 
to bring the structure to the desired temperature and maintain or alter 
the temperature thereof as required. 
Consequently, a need exists for improvements in high temperature 
connections that experience wide variations temperatures. Those skilled in 
the art have long sought and will appreciate the novel features of the 
present invention that solves these problems. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an improved, high 
temperature connector with a replaceable monolithic seating element for 
use in a connector base element that may utilize sturdy aluminum or steel 
construction. 
Another object of the present invention is to provide a readily replaceable 
seat for connecting two capillary columns each having a ferrule sealing 
element. 
A further object of the present invention is to provide for independent 
contact surfaces to apply pressure against a ferrule sealing element for 
initial sealing and subsequent maintenance of a seal during contraction 
and expansion of components over wide temperature changes. 
An additional object of the present invention is to provide a high 
temperature base connector to which multiple connectors may sealingly 
engage. 
The above and other objects of the present invention will become apparent 
from the drawings, the description herein and the appended claims. 
A preferred embodiment of the present invention provides a high 
temperature, gas-tight connection between a first conduit having a first 
bore and a second conduit having a second bore thereby allowing 
communication between the first and second bores. The apparatus includes 
first and second ferrules received on first and second respective 
conduits. The ferrules each include a deformable portion for sealing. 
First and second followers are disposed to be slidably engageable with the 
first and second ferrules, respectively. The followers each have a 
passageway through which the respective conduits extend. First and second 
biasing means are operative to urge the respective followers against the 
respective ferrules. Additionally, a monolithic seating element is 
disposed within a seating chamber of a base element. The monolithic 
seating element has first and second surfaces defining first and second 
receiving formations for the respective ferrules to effect sealing between 
the respective conduits and the respective receiving formations. The 
respective receiving formations are in communication through a passageway 
in the seating element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention combines and improves on the advantages of a 
springbiased high temperature connector in a new, novel connector which 
employs a removably insertable seating element and independent surfaces 
separately engageable with a sealing ferrule. The main internal components 
of the improved high temperature connection 10, for connecting conduits 11 
and 13, are seen in FIG. 1. The apparatus of the present invention may be 
used for connection of various size conduits 11 and 13 including 
relatively small capillary columns having internal diameters ranging from 
0.2-0.8 mm. 
In the presently preferred embodiment, base 12 includes two threaded ports 
14 and 16 on opposing base sides 18 and 20, respectively. Additional ports 
could also be incorporated into base 12 as discussed hereinafter. Base 12 
is preferably formed from aluminum, steel, or other metallic material to 
provide strength at a relatively low cost to connector 10. Seating chamber 
19 interconnects threaded ports 14 and 16. Base 12 may also include 
heating elements (not shown) for quickly heating and/or controlling the 
temperature of the relatively diminutive, with respect to base 12, 
monolithic seating element 9. Although seating element 9 is preferably 
comprised of fused quartz, it may also be comprised of a glass-like 
material or other substances as described subsequently. Glass-like 
materials are generally meant to include ceramics that are typically are 
comprised of silica. 
On either side of base 12, threaded nozzles 22 and 24 engage complementary 
threaded ports 14 and 16, respectively. Threaded nozzles 22 and 24 include 
internal cylindrical bores 26 and 28 that have smooth wall surfaces. 
Flange portions 34 and 36 of the nozzles surround outer threaded bore 
portions 30 and 32 that extend through nozzle end walls 38 and 40, 
respectively. Nozzles 22 and 24 include outer extensions 46 and 48 through 
which extend cylindrical bores 42 and 44, respectively. It is appreciated 
that outer extensions 46 and 48 are moveable into and out of bore 14 and 
16 as nozzles 22 and 24, respectively, are rotated. 
Disposed within nozzles 22 and 24 are followers 50 and 52, quartz seal 
compression springs 54 and 56, and spring pressure adjusting nuts 58 and 
60, respectively. 
Followers 50 and 52 are slidably disposed within bores 26 and 28. Each 
follower includes a flange portion 62 and 64, respectively, that 
effectively centralizes the respective follower in respective bores 26 and 
28. The flange portions 62 and 64 have thereon spring engaging surfaces 66 
and 68. Centrally disposed apertures 70 and 72 extend through the 
respective followers. Conduits 11 and 13 may be disposed within apertures 
70 and 72. Inner boss extensions 74 and 76 extend through bores 42 and 44 
of outer extensions 46 and 48. It will be appreciated that inner boss 
extensions 74 and 76 may be biased with constant pressure as outer 
extensions 46 and 48 separately move into and out of bores 26 and 28 of 
base 12. 
Quartz seal compression springs 54 and 56 encircle a portion of the 
respective followers that, if appropriately sized, may provide 
centralization of the springs with respect to the followers. The quartz 
seal compression springs engage respective spring engagement surfaces 66 
and 68 on the respective followers to apply a biasing pressure. While 
other types of springs could also be used, the quartz spring may be chosen 
for constant biasing pressure over a wide range of temperatures. Other 
springs may be used if a constant biasing pressure is not critical, to 
reduce cost, or if the desired biasing pressure is greater than the 
biasing pressure obtainable from a quartz spring of similar dimensions. 
Spring pressure adjusting nuts 58 and 60 have respective body portions 78 
and 80 that may be sized to centralize respective quartz seal compression 
springs. Centrally disposed apertures 90 and 92 extend through spring 
pressure adjusting nuts 58 and 60, respectively, for use with conduits 11 
and 13. Spring engagement surfaces 82 and 84 on respective threaded 
flanges 86 and 88 may be utilized to adjust biasing pressure. It will be 
appreciated that biasing pressure created by the quartz seal compression 
springs can be adjusted by rotating threaded flanges 86 and 88 using 
spring pressure adjusting nuts 58 and 60 with respect to threaded bores 30 
and 32 of nozzles 22 and 24, respectively. Thus, biasing pressure may be 
applied to respective inner boss extensions 74 and 76 separately from any 
biasing or deforming pressure that may be applied via outer extensions 46 
and 48. 
Outer extensions 46 and 48 apply pressure against respective ferrule flange 
portions 94 and 96 and thereby with seating element 9. Ferrule flange 
portions 94 and 96 limit movement of the ferrules and seating element 9 
after contact with end portions thereof. Ferrules 98 and 100 include 
deformable portions that seal with sealing surfaces on monolithic seating 
element 9. The term "deformable" as used herein refers to a material 
which, under compression, deforms to the extent necessary to achieve a 
gas-tight seal between the ferrule and the engaged surface or surfaces and 
conduits 11 and 13. Respective centrally disposed internal apertures 102 
and 104 (FIG. 2) may include deformable portions for sealing conduits 11 
and 13 even if the conduits are slightly undersize with respect the 
apertures. In a preferred embodiment, ferrules 98 and 100 have deformable 
cylindrical portions 106 and 108 (See FIG. 2) that make line contact along 
lines 110 and 112 for gas-tight sealing with a frustoconical receiving 
formation described subsequently. More specifically cylindrical portions 
106 and 108 include a circular transverse cross-section that engages a 
frustoconical receiving formation substantially in line contact in the 
locus a deformable portion of ferrules 98 and 100. Deformable cylindrical 
portions 106 and 108, or other deformable portions of ferrules 98 and 100 
may also be used to form the seal around conduits 11 and 13. 
Disposed within cylindrical seating chamber 19 is monolithic seating 
element 9. Monolithic glass-like seating element 9 is typically comprised 
of fused quartz or other glass-like materials to provide an inert material 
for use at high temperatures and over wide variations in temperature. 
Seating element 9 is preferably cylindrical and mates to seating chamber 
19. For this reason, it will be appreciated that sealing element 9 is 
slidably disposed within cylindrical seating chamber 19 and is therefore 
easily replaceable as may be necessary, for instance, due to breakage or 
chemical contamination. The fact that monolithic seating element 9 is 
slidable allows it to self-adjust its position between ferrules 98 and 100 
as required to approximately equal pressure on both ends thereof. Thus, 
quartz sealing compression springs 54 and 56 interact with each other for 
sealing purposes due to the slidable nature of monolithic seating element 
9. Seating element 9 has frustoconical surfaces 111 and 113 formed therein 
interconnected by bore 109. The frustoconical surfaces generally define 
corresponding receiving surfaces in the locus of 114 and 116 for forming 
gas-tight seals through engagement with deformable cylindrical portions 
106 and 108. 
While monolithic seating element 9 is shown for use with two co-axial 
nozzles having corresponding conduits to be connected, it may also connect 
nozzles or ferrules disposed at right angles or other angles with respect 
to each other. It may be used with more than two conduits. For instance, 
monolithic seating element 9 could have a Y-shaped internal passageway or 
a T-shaped internal passageway for use with additional ports in base 12. 
This construction allows for multiple frustoconical receiving surfaces. 
Base 12 may also be part of a larger vessel whereby only one threaded port 
and ferrule may be provided. The construction of the seating element 9 
could allow replacement through a passageway transverse to the conduits to 
be connected or a passageway generally parallel to the conduits as shown. 
In operation, monolithic seating element 9 is inserted into cylindrical 
seating chamber 19 if it is not already present. Since monolithic seating 
element 9 is slidable, it is self adjusting between ferrules 98 and 100. 
Other arrangements could also be used for securing element 9. For 
instance, a transverse passageway (not shown) through which seating 
element 9 may be movable could include stop surfaces for locking element 9 
in place. 
Conduits 11 and 13, which may be capillary columns, are then threaded 
through respective components as shown and the various components are 
connected to base 12. Due to the small size of capillary columns, it is 
preferable to have beveled or frustoconical inlets, such as beveled inlet 
115 (shown as conduit 11 enters connection apparatus 10) to aid in 
threading capillary columns. It may be desirable to adjust biasing 
pressure applied to ferrule followers 50 and 52 prior to insertion of 
corresponding nozzles 22 and 24 into base 12. As noted, the biasing 
pressures will interact due to the slidable mounting of seating element 9. 
Spring pressure adjusting nuts 58 and 60 are used for this purpose. After 
assembly as shown in FIG. 1, a gas-tight connection may then be effected 
between conduits 11 and 13 by applying pressure to ferrules 98 and 100 via 
flange 34 and 36. 
The present invention allows pressure to applied to each ferrule by 
separate concentrically or annularly disposed inner boss extensions 74, 76 
and outer extensions 46, 48 respectively. Generally, pressure is applied 
to the ferrules for two separate reasons. Initial pressure may be applied 
to deform the ferrule for sealing with seating element 9 and with conduits 
11 and 13. Biasing pressure is applied to the ferrules to maintain the 
seal as temperatures vary and the components expand and contract 
accordingly. The use of two surfaces for applying the pressures eliminates 
any interplay between the ferrule follower and extensions 46 and 48. 
Flanges 34 and 36 rotate to apply pressure through extensions 46 and 48 to 
deform the ferrules thereby effecting the initial gas-tight sealing with 
seating element 9 and conduits 11 and 13. The spring loaded biasing 
pressure corrects for expansion and contractions that may occur especially 
if wide temperature swings are anticipated. The initial gas-tight seal 
effected by rotating flanges 34 and 36 may not be adequate to maintain the 
seal without the biasing pressure to correct for expansion and 
contractions of material in the connector 10. On the other hand, the 
spring loaded biasing pressure administered through inner boss extensions 
74 and 76 may not be adequate to effect the initial seal between the 
ferrules, conduits and seating element 9. This may be especially true if 
the conduits are undersize with respect to the ferrules. 
While seating element 9 has been discussed in terms of glass-like material 
or fused quartz, other materials may also be used. For instance, when it 
is not necessary to have a material as inert as fused quartz, then 
materials including metals could be used for manufacture of seating 
element 9. Other specific materials may also be suitable for certain 
configurations and fluids or gasses. Cost may also be a factor to be 
considered in selection of material for a seating element, especially 
where the demands on the selected material will not be extreme. 
The aspect of line contact sealing is discussed more thoroughly in 
exemplary U.S. Pat. Nos. 4,991,883 and U.S. Pat. No. 5,163,722 that, as 
previously stated, are incorporated herein by reference. 
The foregoing description of the invention has been directed in primary 
part to particular preferred embodiments in accordance with the 
requirements of the patent statutes and for purposes of illustration. It 
will be apparent, however, to those skilled in the art that many 
modifications and changes may be made without departing form the scope and 
spirit of the invention. Therefore, the invention is not restricted to the 
preferred embodiment illustrated but covers all modifications that may 
fall within the scope of the following claims.