U.S. patent number 3,885,438 [Application Number 05/365,552] was granted by the patent office on 1975-05-27 for automatic fluid injector.
Invention is credited to Rano J. Harris, Jr., Rano J. Harris, Sr..
United States Patent |
3,885,438 |
Harris, Sr. , et
al. |
* May 27, 1975 |
Automatic fluid injector
Abstract
Apparatus for automatically accurately measuring and injecting
quantities of fluid specimens, or samples, into various media,
e.g., a receptacle or inlet of a modern analytical instrument. The
automatic fluid injector includes generally (a) an injector, or
syringe assembly, inclusive of a needle syringe per se, (b) an
injector feed assembly for automatically continuously purging,
cleaning and filling the said syringe, and (c) a magazine, or feed
tray, for transporting fluid specimen containing vials to the
injector feed assembly for pick-up of the fluid specimen, and
delivery to the syringe of the syringe assembly. Means are provided
for movement of the syringe along a straight path for insertion and
withdrawal of the needle from the inlet of the analytical
instrument. A reciprocable hollow probe, or pair of probes,
associated with the injector feed assembly picks up a fluid
specimen from a fluid containing vial delivered by the magazine or
feed tray, and conveys the fluid to the syringe of the syringe
assembly. A predetermined portion of the fluid specimen is trapped
and accurately measured within the syringe, and the syringe is
carried forward to insert the needle portion thereof through the
inlet of the analytical instrument, the sample is then injected,
and the needle then withdrawn. The several assemblies are properly
housed, and automatic controls provide for cyclically cleaning,
purging, filling and injecting fluid specimens.
Inventors: |
Harris, Sr.; Rano J. (Baton
Rouge, LA), Harris, Jr.; Rano J. (Baton Rouge, LA) |
[*] Notice: |
The portion of the term of this patent
subsequent to August 28, 1990 has been disclaimed. |
Family
ID: |
26918003 |
Appl.
No.: |
05/365,552 |
Filed: |
May 31, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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223663 |
Feb 4, 1972 |
3754443 |
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Current U.S.
Class: |
73/863.81 |
Current CPC
Class: |
G01N
35/1079 (20130101) |
Current International
Class: |
G01N
1/00 (20060101); G01n 001/14 () |
Field of
Search: |
;73/423A,422GC
;23/259 |
References Cited
[Referenced By]
U.S. Patent Documents
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3479880 |
November 1969 |
Mutter et al. |
3754443 |
August 1973 |
Harris, Sr. et al. |
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Primary Examiner: Swisher; S. Clement
Attorney, Agent or Firm: Proctor; Llewellyn A.
Parent Case Text
REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of related U.S.
application Ser. No. 223,663, filed Feb. 4, 1972, U.s. Pat. No.
3,754,443, the disclosure of which is herewith fully incorporated
by reference.
Claims
Having described the invention, what is claimed is:
1. In apparatus for repetitively accurately measuring and injecting
preselected quantities of fluid specimens into a media such as an
inlet to an analytical instrument, the combination comprising
a housing, which can be mounted adjacent an inlet leading into the
analytical instrument,
a tubular member located within the housing, said tubular member
including a pair of communicated openings therethrough, a first
opening of the pair extending through the tubular member and
housing, a second axial opening adjacent to and communicated with
the said first opening which can be aligned upon the inlet leading
into the analytical instrument,
a needle syringe mounted upon the forward end of a piston of a
cylinder-piston unit affixed upon the housing, said syringe
including
a barrel, including forward and rearward tubular portions, formed
by an enclosing wall defining an axial opening,
a chamber of substantially cylindrical-shaped cross section located
at the front end of the forward portion of the barrel,
an enlarged chamber opening communicating with and located rearward
of the said chamber,
an outlet located within the forward portion of the barrel,
rearward of the enlarged chamber opening,
a hollow needle, provided with an opening in the dispensing end
thereof, mounted at the forward end of the barrel, the opening
through said needle communicating with the axial opening through
the barrel,
a reciprocable plunger mounted within the barrel, said plunger
including a forward portion fitted snugly within the chamber of
substantially cylindrical-shaped cross section located at the
forward end of the barrel and a rearward portion provided with an
enlarged head of cross-section corresponding substantially with the
cross-section of the rearward portion of the barrel within and
through which the head moves on reciprocation of the plunger,
a seal located within and separating the forward and rearward
portions of said barrel, the plunger being extended therethrough
and reciprocable therein such that the head of the plunger
traverses the rearward tubular portion of the barrel and the
forward portion of the plunger traverses the forward portion of the
barrel,
a plunger adjustment assembly located within the rearward portion
of the barrel, within the path of travel of said plunger, wherein
is included an end plug which fits within and encloses the rearward
portion of said barrel, and a pair of telescoping members located
forward of the said enclosing end plug, and means whereby the pair
of telescoping sections can be lengthened or shortened in an axial
direction along the length of the rearward tubular portion of the
barrel such that the distance travelled by the reciprocable plunger
can be preset as desired,
means provided within the rearward tubular portion of the barrel
for reciprocation of the plunger,
an injector feed unit including a hollow probe provided with
communicating upper and lower side openings mounted on the forward
end of a piston of a cylinder-piston unit affixed upon the housing,
said probe being aligned upon the said first opening of the tubular
member within and through which the probe can be reciprocated by
movement of the piston, and extended through the said first
opening, and
means for transporting a fluid specimen containing a vial, with a
septum cap, below the said first opening and into the path of the
hollow probe for penetration of the septum for pick-up of the fluid
specimen via the lower side opening of the probe and conveyance of
same via the upper opening of the probe, through the communication
connecting the first and second openings, and into the opening
within the dispensing end of the needle and into the
cylindrical-shaped chamber in the forward barrel portion of the
syringe, which fluid specimen can flow therethrough to the enlarged
chamber outlet located within the forward portion of the barrel,
and a predetermined quantity of fluid specimen can be trapped and
accurately measured within the forward barrel portion of the
syringe by forward movement of the tip of the plunger past the
outlet and enlarged chamber located within the forward portion of
the barrel, the needle of the needle syringe then thrust through
the said second opening of the tubular member and into the inlet to
the analytical instrument, and the accurately measured quantity of
fluid specimen injected into the inlet by continued forward
movement of the plunger.
2. The apparatus of claim 1 wherein the forward and rearward
portions of the syringe barrel are constituted of two separate
tubular members, a small-diameter forward tubular member, within
which is provided the cylindrrical shaped forward chamber, enlarged
chamber outlet and side opening, and within the forward portion of
which the hollow needle is sealed, and a rearward larger-diameter
tubular member, the wall of which is provided with forward and
rearward inlet-outlet ports for ingress and egress of pressurized
fluid which impinges on the head of the plunger, which lies
therein, for reciprocation of the plunger, the plunger being fitted
through a seal located between the said forward and rearward
tubular members such that the forward portion of the plunger
traverses the forward tubular member while the head of the piston
traverses the rearward tubular member.
3. The apparatus of claim 1 wherein the plunger adjustment
assembly, which is located within the rearward portion of the
barrel, and includes an end plug which fits within and encloses the
rearward portion of said barrel, is comprised of
outer and inner telescoping members fitted through said end
plug,
a shaft extendeed from the outer telescoping member which is fitted
through an opening within the said plug portion,
an enlarged perforated head located on the forward end of said
shaft against the forward face of which the head of the plunger can
impinge, and the
A tubular section, the forward end of which provides a stop surface
against which the perforated head of the shaft can impinge on
rearward contact by the plunger, and which, in combination with
said enlarged head and shaft, provides telescoping members which
can be lengthened or shortened in an axial direction along the
length of the rearward tubular portion of the barrel, the said
plunger adjustment assembly including
a helical spring fitted concentrically about the said tubular
section, enlarged head and shaft and seated between the rearward
face of the enclosed end of the said tubular section and the
forward face of the plug portion sealing the rearward portion of
said barrel.
4. The apparatus of claim 1 wherein the cylinder-piston unit of the
injector feed unit is a double-acting cylinder-piston unit
comprising a barrel within which pressurized fluid can be admitted
or expelled via inlet-outlet ports located on opposite sides of the
area of traverse of the enlarged head affixed upon an end of the
piston of the cylinder-piston unit, the probe constitutes the
piston of the cylinder-piston unit in that it is directly affixed
via one of its terminal ends to an enlarged head and reciprocable
therewith when acted upon by ingress and egress of pressurized
fluid admitted or expelled via the said inlet-outlet ports.
5. In an apparatus for repetitively accurately measuring and
injecting preselected quantities of fluid specimens into a media
such as an inlet to an analytical instrument, the combination
comprising
a housing, which can be mounted adjacent an inlet leading into the
analytical instrument,
a tubular member located within the housing, said tubular member
including a pair of communicated openings therethrough, a first
opening of the pair extending through the tubular member and
housing, a second opening adjacent to and communicated with the
first opening which can be aligned upon the inlet leading into the
analytical instrument,
a needle syringe mounted upon the forward end of a piston of a
cylinder-piston unit affixed upon the housing, said syringe
including
a barrel, including forward and rearward tubular portions, formed
by an enclosing wall defining an axial opening,
a hollow needle, provided with an opening in the dispensing end
thereof, mounted at the forward end of the barrel, the opening
through the said needle communicating with the axial opening
through the barrel,
a reciprocable plunger mounted within the barrel, said plunger
including a forward portion fitted snugly within the axial opening
within the forward portion of said barrel and a rearward portion
provided with an enlarged head of cross-section corresponding
substantially with the cross-section of the rearward portion of the
barrel within which the head moves on reciprocation of the
plunger,
a seal located within and separating the forward and rearward
portions of said barrel, the plunger being extended therethrough
and reciprocable therein such that the head of the plunger
traverses the rearward tubular portion of the barrel and the
forward portion of the plunger traverses the forward portion of the
barrel,
a plunger adjustment assembly located within the rearward portion
of the barrel, within the path of travel of said plunger, wherein
is included a plug which fits within and encloses the rearward
portion of said barrel, and a pair of telescoping sections located
forward of the said enclosing plug, such that the pair of
telescoping sections can be lengthened or shortened in an axial
direction along the length of the rearward tubular portion of the
barrel to preset the distance travelled by the plunger,
inlet-outlet ports located at opposite ends of the rearward tubular
portion of the barrel through which a pressurized fluid can be
injected for reciprocation of the plunger,
an injector feed unit including a pair of hollow probes, each of
which are provided with upper an lower openings, mounted on the
forward end of a piston of a cylinder-piston unit affixed upon the
housing, pressurized fluid inlet means associated with an upper
opening of one of the pair of probes, said probes being aligned
upon the said first opening through the tubular member within and
through which the probes can be reciprocated by movement of the
piston, and extended through the said first opening, and
means for transporting a fluid specimen containing a vial, with a
resilient puncturable septum cap, below the said first opening and
within the path of the pair of hollow probes for penetration of the
septum cap by the probes, whereby pressurized fluid injected into
the vial by one of the pair of probes pressurizes the fluid
contents of the vial so that the fluid contents of the vial can be
forced into a lower opening of the opposite probe of the pair and
conveyed through the axial opening, and through an upper opening
into the needle and into the forward tubular barrel portion of the
syringe.
6. In apparatus for repetitively accurately measuring and injecting
preselected quantities of fluid specimens into a media such as an
inlet to an analytical instrument, the combination comprising
a housing, which can be mounted adjacent an inlet leading into the
anaytical instrument,
a tubular member located within the housing, said tubular member
including a pair of communicated openings therethrough, a first
opening of the pair extending through the tubular member and
housing, a second opening adjacent to and communicated with the
said first opening which can be aligned upon the inlet leading into
the analytical instrument,
a needle syringe mounted upon the forward end of a piston of a
cylinder-piston unit affixed upon the housing, said syringe
including
a barrel, including forward and rearward tubular portions, formed
by an enclosing wall defining an axial opening,
a hollow needle, provided with an opening in the dispensing end
thereof, mounted at the forward end of the barrel, the opening
through the said needle communicating with the axial opening
through the barrel,
a tubular flange closing the opposite end of the barrel,
a hollow reciprocable plunger mounted within the barrel, said
plunger including a forward portion fitted snugly within the axial
opening through the end of the barrel, and a rearward portion which
extends through the axial opening within the enclosing tubular
flange,
a pair of serially connected double-acting cylinder-piston units, a
rearward double-acting cylinder-piston unit including a barrel, an
enclosing rearward end wall and a tubular forward end wall, a
reciprocable piston the shaft portion of which is fitted within and
projected through the axial opening of the tubular forward end wall
and the enlarged head of which is located within the said barrel,
and inlet-outlet ports located at opposite ends of said barrel for
admission of pressurized fluid for reciprocation of the piston, and
a forward double-acting cylinder-piston unit including a barrel the
rearward end of which is enclosed by the tubular forward end wall
of said rearward double-acting cylinder-piston unit, a forward
enclosing tubular end wall, a reciprocable hollow piston the shaft
portion of which is fitted within and projected through the axial
opening of the tubular forward enclosing end wall and the enlarged
tubular head of which is fitted within the said barrel, the shaft
of the piston unit being fitted and slidable within the axial
opening through said reciprocable hollow piston, the said forward
double-acting cylinder-piston unit also including inlet-outlet
ports for admission of pressurized fluid for reciprocation of said
hollow piston,
a tubular member, provided with a lateral opening, movable between
the tubular flange closing the end of the barrel of the syringe and
the forward tubular end wall which encloses the forward
double-acting cylinder-piston unit, separated one from the other by
spacing support bars, the hollow plunger of the syringe barrel
being affixed to said tubular member at one end and in axial
communication therewith and with the said lateral opening, the
hollow piston of the forward double-acting cylinder-piston unit
being affixed the opposite end of said tubular member, and in axial
communication with said axial opening through the movable tubular
member such that the piston shaft of said rearward double-acting
cylinder-piston unit can be reciprocated therethrough to open the
lateral opening to communication with the dispensing end of the
needle or close off such communication by closure of the lateral
opening and rearward end of the hollow plunger,
an injector feed assembly including a hollow probe provided with
communicating upper and lower openings mounted on the forward end
of the piston of a cylinder-piston unit affixed upon the housing,
said probe being aligned upon the said first axial opening through
the tubular member within and through which the probe can be
reciprocated by movement of the piston, and extended through the
said first axial opening,
means for transporting a fluid specimen contained in a vial, with a
resilient, puncturable closure, below the said first axial opening
and into the path of the hollow probe for penetration of said
closure by the probe, and
means for pressurizing the fluid contents of the vial so that the
fluid specimen contained within the vial can be transferred via the
lower and upper side openings of the probe into the opening of the
needle and into the chamber of the syringe.
7. In apparatus for repetitively accurately measuring and injecting
preselected quantities of fluid specimens into a media such as an
inlet to an analytical instrument, the combination comprising
a housing, which can be mounted adjacent an inlet leading into the
analytical instrument,
a tubular member mounted within the housing, said tubular member
including an inner hermetically sealed chamber and a gas inlet to
said chamber and a pair of communicated openings, a first axial
opening of the pair extending through the tubular member, said
chamber and housing, and a second opening adjacent to and
communicated with said first axial opening which can be aligned
upon the inlet leading into the analytical instrument,
a needle syringe mounted upon a piston of a cylinder-piston unit
affixed upon the housing, the needle of which is aligned upon said
second opening through the tubular member within and through which
the needle can be reciprocated by movement of the piston, said
syringe including a barrel comprised of forward and rearward
tubular portions separated one from the other by sealing means, the
forward tubular portion of said syringe providing a chamber for
containing a predetermined quantity of fluid for injection via an
opening within the dispensing end of the needle which is mounted on
the front end of the said forward tubular portion, the rearward
tubular portion of said syringe containing a plunger, the front end
of which can be reciprocated within the chamber in the forward
portion of the syringe, the plunger providing in its retracted
position a chamber which can be filled with fluid in predetermined
quantity from the dispensing end of the needle which, on subsequent
forward thrust of the plunger, the fluid specimen can be injected
through the dispensing end of the needle,
an injector feed assembly including a hollow probe provided with
communicating upper and lower openings mounted on the forward end
of the piston of a cylinder-piston unit affixed upon the housing,
said probe being aligned upon the said first axial opening through
the tubular member within and through which the probe can be
reciprocated by movement of the piston, and extended through the
said first axial opening,
means for transporting a fluid specimen contained in a vial, with a
resilient, puncturable closure, below the said first axial opening
and into the path of the hollow probe for penetration of said
closure by the probe,
whereby pressurized gas can be injected via its inlet into said
hermetically sealed chamber on alignment of the upper probe opening
with said chamber and the fluid contents of the vial pressurized by
delivery of the gas into the vial via passage through the probe, on
discontinuance of the alignment of said upper probe opening with
the pressurized hermetically sealed chamber which occurs by the
downward movement of the probe the applied gas pressure is
discontinued, and after entry of the lower probe opening into the
fluid contents of the vial, a fluid specimen contained within the
vial can be transferred via the probe into the opening of the
needle and into the chamber of the syringe.
8. The apparatus of claim 7 wherein the rearward tubular portion
constituting the barrel of said needle syringe comprises a
double-acting cylinder piston unit which includes forward and
rearward inlet-outlet ports through which pressurized fluid can be
admitted to reciprocate the piston, the piston is also the plunger
of the forward portion of the syringe, and the rearward tubular
portion of said syringe constituting the double-acting cylinder
piston unit includes a plunger adjustment assembly comprising an
end plug of relative large cross-section located within and
enclosing the rearward wall of the cylinder piston unit, and a pair
of telescoping members located forward of the enclosing end plug,
and means whereby the pair of telescoping sections can be
lengthened or shortened in an axial direction along the length of
the rearward tubular portion of the syringe such that the distance
within which the plunger of the double-acting cylinder piston unit
is free to travel can be preset, as desired.
9. The apparatus of claim 7 wherein the forward portion of the
barrel of the needle syringe mounted on the piston of a
cylinder-piston unit is provided with a side opening such that
fluid transferred from the vial through the probe can be passed in
a stream through the chamber to exit via the side opening
therefrom, thereafter a predetermined amount of a fluid specimen
can be trapped for subsequent delivery by limited forward movement
of the plunger which blocks said side opening, and thereafter the
needle of the needle syringe can be thrust through said second
opening of the tubular member and into the inlet to the analytical
instrument, and the accurately measured quantity of fluid specimen
injected into the inlet by continued forward movement of the
plunger.
10. The apparatus of claim 7 wherein the needle syringe mounted on
the piston of the cylinder-piston unit is one which comprises
a barrel, including forward and rearward tubular portions, formed
by an enclosing wall defining an axial opening,
a chamber of substantially cylindrical-shaped cross-section located
at the front end of the forward portion of the barrel,
an enlarged chamber opening communicating with and located rearward
of the said chamber,
an outlet located within the forward portion of the barrel,
rearward of the enlarged chamber opening,
a hollow needle, provided with an opening in the dispensing end
thereof, mounted at the forward end of the barrel, the opening
through said needle communicating with the axial opening through
the barrel,
a reciprocable plunger mounted within the barrel, said plunger
including a forward portion fitted snugly within the chamber of
substantially cylindrical-shaped cross-section located at the
forward end of the barrel and a rearward portion provided with an
enlarged head of cross-section corresponding substantially with the
cross-section of the rearward portion of the barrel within and
through which the head moves on reciprocation of the plunger,
a seal located within and separating the forward and rearward
portions of said barrel, the plunger being extended therethrough
and reciprocable therein such that the head of the plunger
traverses the rearward tubular portion of the barrel and the
forward portion of the plunger traverses the forward portion of the
barrel.
11. The apparatus of claim 10 wherein the syringe includes
a plunger adjustment assembly located within the rearward portion
of the barrel, within the path of travel of said plunger, wherein
is included an end plug which fits within and encloses the rearward
portion of said barrel, and a pair of telescoping members located
forward of the said enclosing end plug, and means whereby the pair
of telescoping sections can be lengthened or shortened in an a
axial direction along the length of the rearward tubular portion of
the barrel such that the distance travelled by the reciprocable
plunger can be preset as desired.
12. In apparatus for repetitively accurately measuring and
injecting preselected quantities of fluid specimens into a media
such as an inlet to an analytical instrument, the combination
comprising
a housing, which can be mounted adjacent an inlet leading into the
analytical instrument,
a tubular member mounted within the housing, said tubular member
including a pair of communicated openings therethrough, a first
axial opening of the pair extending through the tubular member and
housing, and a second opening adjacent to and communicated with
said first axial opening which can be aligned upon the inlet
leading into the analytical instrument,
a needle syringe mounted upon the forward end of a piston of a
cylinder-piston unit affixed upon the housing, the needle of which
is aligned upon said second opening through the tubular member
within and through which the needle can be reciprocated by movement
of the piston, said syringe including a barrel comprised of forward
and rearward tubular portions separated one from the other by
sealing means, the forward tubular portion of said syringe
providing a chamber of substantially cylindrical-shaped cross
section located at the front end of the forward portion of the
barrel for containing a predetermined quantity of fluid for
injection via an opening within the dispensing end of the needle
which is mounted on the front end of the said forward tubular
portion, an enlarged chamber opening communicating with and located
rearward of the said chamber, an outlet located within the forward
portion of the barrel, rearward of the enlarged chamber opening,
the rearward tubular portion of said syringe containing a plunger,
the front end of which can be reciprocated within the chamber in
the forward portion of the syringe, the plunger providing, in a
retracted position a channel for flow of fluid from the dispensing
end of the needle through the chamber, enlarged chamber opening,
and outlet located within the forward portion of the barrel, and in
a forward position wherein the forward end of the plunger is
located in front of said enlarged chamber opening, a closed chamber
wherein a fluid specimen can be contained in predetermined
quantity, and on subsequent forward thrust of the needle of the
syringe into the inlet of the analytical instrument the fluid
specimen can be injected through the dispensing end of the
needle,
an injector feed assembly including a hollow probe provided with
communicating upper and lower openings mounted on the forward end
of the piston of a cylinder-piston unit affixed upon the housing,
said probe being aligned upon the said first axial opening through
the tubular member within and through which the probe can be
reciprocated by movement of the piston, and extended through the
said first axial opening,
means for transporting a fluid specimen contained in a vial, with a
resilient, puncturable closure, below the said first axial opening
and into the path of the hollow probe for penetration of said
closure by the probe, and
means for pressurizing the fluid contents of the vial so that the
fluid specimen contained within the vial can be transferred via the
lower and upper side openings of the probe into the opening of the
needle and into the chamber of the syringe.
13. The apparatus of claim 12 wherein the tubular member mounted
within the housing and containing the pair of communicated openings
is provided within an internal enlarged hermetically sealed
chamber, said chamber being provided with fluid inlet means, such
that an upper opening within the hollow probe, which is fitted and
traversable within the said first axial opening of the tubular
member, and a lower probe opening are in communication via the
opening through the hollow probe, at such time the upper probe
opening is located within said chamber a pressurized fluid can be
transmitted through the hollow probe to a vial to pressurize the
fluid specimen contained therein for transfer via the probe to the
needle opening and into the chamber of the syringe.
14. The apparatus of claim 12 wherein the cylinder-piston unit of
the injector feed unit is a double-acting cylinder-piston unit
comprising a barrel within which pressurized fluid can be admitted
or expelled via inlet-outlet ports located on opposite sides of the
area of traverse of the enlarged head affixed upon an end of the
piston of the cylinder-piston unit, the probe constitutes the
piston of the cylinder-piston unit in that it is directly affixed
via one of its terminal ends to an enlarged head and reciprocable
therewith when acted upon by ingress and egress of pressurized
fluid admitted or expelled via the said inlet-outlet ports to the
said first tubular member.
15. The apparatus of claim 13 wherein the hermetically sealed
chamber is formed between an abutting pair of tubular sections of
cylindrical shape, and a tubular shaped bushing is fitted
concentrically therein to seal the interface between the abutting
upper and lower tubular sections.
16. The apparatus of claim 13 wherein the pair of communicated
openings of the said tubular member intersect, and are located
within the same plane.
17. The apparatus of claim 12 wherein the means for pressurizing
the fluid contents of a vial are comprised of an opposed pair of
rollers, with projections, which compress the walls of a vial, a
vial in this instance being constituted of a flexible material.
18. The apparatus of claim 12 wherein the means for pressurizing
the fluid contents of a vial are comprised of the piston of a
cylinder-piston unit which compresses the walls of a vial, a vial
in this instance being provided with an enclosing wall of fluted
cross-section and constituted of a flexible material.
19. The apparatus of claim 12 wherein the rearward tubular portion
constituting the barrel of said needle syringe comprises a
double-acting cylinder piston unit, the piston of which is also the
plunger of the forward portion of the syringe.
20. The apparatus of claim 19 wherein the rearward tubular portion
of said syringe constituting the double-acting cylinder piston unit
includes forward and rearward inlet-outlet ports through which
pressurized fluid can be admitted to reciprocate the piston.
21. The apparatus of claim 20 wherein the rearward tubular portion
of said syringe constituting the double-acting cylinder piston unit
includes a plunger adjustment assembly comprising an end plug of
relative large cross section located within and enclosing the
rearward wall of the cylinder-piston unit, and a pair of
telescoping members located forward of the enclosing end plug, and
means whereby the pair of telescoping sections can be lengthened or
shortened in an axial direction along the length of the rearward
tubular portion of the syringe such that the distance within which
the plunger of the double-acting cylinder piston unit is free to
travel can be preset, as desired.
22. The apparatus of claim 21 wherein the end plug is tubular and
provided with an externally threaded projection, threadably engaged
to internal threads located within the rearward wall of the
cylinder piston unit, and the telescoping members include a
rotatable member, of tubular design, mounted within the axial
opening thereof and is internally threaded, and a shaft provided
with the enlarged forward head is externally threaded and
threadably engaged within the rotatable tubular member such that
rotation of the rotatable member provides the telescoping action
which lengthens or shortens the distance that the plunger is free
to travel.
Description
The present invention relates generally to an automatic fluid
injector, or apparatus, for automatically measuring and injecting
accurately measured quantities of fluids. More particularly, it
relates to apparatus, especially fluid injection devices or
syringes, for continuous automatic measurement and injection of
very small, accurately measured quantities of liquid specimens into
various media, e.g., modern analytical instruments.
Fluid injection devices, particularly needle syringes, have gained
wide acceptance by the industry, and by the scientific community,
generally, for use in dispensing infinitesimally small, accurately
measured fluid specimens, e.g., to modern analytical instruments
such as mass spectrometers and gas chromatographs. Such syringes
embody apparatus comprising a tubular body or barrel, on the
forward end of which is fitted a hollow or tubular needle and, at
the opposite end, a slidable plunger which travels within the
barrel. Syringes of such character, and related devices, are
capable of dispensing very small fluid specimens, accurately
measured, on the order of a few microliters, or very small
fractions of a microliter, e.g., from about 0.01 to about 5
microliters, or fractional parts thereof.
In recent years, due to the abvious advantages offered by the
combination of automatic fluid injection instruments, and modern
data gathering techniques, which greatly reduce operating manpower
without decrease in accuracy, there is considerable demand for
improved automated devices of these types.
It is, accordingly, a primary object of the present invention to
provide new and novel fluid injectors readily adaptable to
automatically perform the basic cyclic functions of filling,
purging and cleaning, and injecting.
A particular object is to provide apparatus capable of continuously
cyclically serially withdrawing precisely measured infinitesimally
small quantities of gas or liquid specimens from prefilled vials or
containers, injecting the specimens in seriatim in reproducible
quantities, and cleaning prior to subsequent withdrawal and
injection of a subsequent specimen.
A further object is to provide apparatus of simple and relatively
inexpensive construction, particularly apparatus which can be
readily serviced and operated, which apparatus readily lends itself
to rapid mass production techniques.
These objects and others are achieved in accordance with the
present invention which embodies improvements in automatic fluid
injector systems. A preferred type of automatic fluid injector is
comprised generally of (a) an injector, or syrings assembly,
inclusive of a needle syringe per se, (b) an injector feed
assembly, or unit, for automatically purging, cleaning and filling
the said syringe, and (c) a magazine, or feed tray, for
transporting fluid specimen containing vials and positioning same
in relation to the injector feed assembly for pick-up of the fluid
specimen, and delivery to the syringe of the syringe assembly. The
automatic fluid injector also includes automation or control means
for repetitively and automatically carrying out the functions of
cleaning, purging and filling the syringe with predetermined
quantities of fluid specimens, in timed sequence, and the several
subassemblies of the automatic fluid injector are generally
contained within a housing, or housings. The sub-assemblies
constituting (a) the injector, or syringe assembly, inclusive of
syringe, and (b) the injector feed assembly are preferably
contained within a single housing below which is mounted (c) the
magazine, or feed tray.
The characteristics of preferred automatic fluid injectors, and the
principle of their operation, will be more fully understood by
reference to the following detailed description of preferred
embodiments, and to the attached drawings to which reference is
made in the detailed description. Similar numbers are used to
represent similar parts or components in different figures, and
letter subscripts are used, with a given whole number, to designate
a plurality of generally analogous parts or components. Where a
capital letter is used alone with reference to a component, its use
is intended to point out a sub-assembly of the combination.
In the drawings:
FIGS. 1 through 8 describe a series of views depicting a preferred
automatic fluid injector, and its operation in the sequence of
sampling, trapping, measuring and injecting an accurately measured
volume of fluid into a medium, e.g., an inlet to an analytical
instrument.
FIG. 1 is a section view of a preferred automatic fluid injector,
including an automated syringe, mounted on a plate, or housing,
useful for positioning said syringe, in relation to an inlet, or
medium, wherein an accurately measured fluid specimen is to be
injected, the automatic fluid injector including, in combination,
(a) an injector, syringe or syringe assembly, (b) in injector feed
assembly (or assembly for supplying a fluid specimen to the syringe
of the syringe assembly, and (c) a magazine or feed tray;
FIGS. 2 and 3 are sections of the injector feed assembly, with a
fragmentary view of the magazine or feed tray, depicting their
operation and function;
FIG. 4 is a section of the overall combination depicted by
reference to FIG. 1, showing a continued progression of the
operation and function of the automatic fluid injector; and
FIGS. 5-8 are views or necessary fragmentary views showing
continuation of the progression of operation of the automatic fluid
injector, previously referred to, through a completion of a cycle
of operation;
FIGS. 9 through 11 are section views depicting a preferred type of
syringe, and its operation, as a part of the combination depicted
by reference to preceding FIGS. 1 through 8;
FIGS. 12 and 13 are sectional views of other preferred modes of
injector feed assemblies, as a part of the overall combination
depicted by reference to FIGS. 1 through 8, or FIGS. 1 through 8 as
modified by the embodiments of FIGS. 9 through 11;
FIGS. 14 and 15 depict sectional views of another preferred type of
injector feed assembly, and its principle of operation, useful in
any of the combination previously described; and
FIGS. 16 through 19 depict another preferred type of syringe, and
its operation, for use in any of the combinations previously
described.
Referring to FIG. 1, and to FIGS. 1 through 8 generally, there is
shown the principle components of an automatic fluid injector,
according to one form of the invention, this including the
combination of (a) an injector, or syringe assembly A, (b) an
injector feed assembly B, and (c) a magazine, or feed tray, C for
carrying or transporting individual fluid-containing vials. These
several units of the automatic fluid injector are generally
contained within a housing and are responsive to automatic control
means such as described, e.g., by reference to application Ser. No.
223, 663, supra. In brief compass, the overall nomenclature and
function of these several units are as follows: (a) The injector,
or syringe assembly A, is comprised generally of a needle syringe
10, which includes the usual barrel 11, Cannula or needle 12
mounted on the front end thereof, and plunger 13 mounted within
said barrel 11. The plunger 13 is itself actuated by a
double-acting cylinder piston unit 20, which forms a part of the
overall needle syringe 10, and syringe 10 is mounted and carried on
the forward end of a piston 31 of a double-acting cylinder piston
unit 30 and reciprocable therewith for movement of the syringe 10
along a straight path in alignment with, e.g., a septum inlet 90;
(b) the injector feed assembly B, the function of which is to
provide a fluid specimen to the syringe 10, is comprised generally
of a double-acting cylinder piston unit 50, the piston 51 thereof
being a reciprocable hollow probe associated with means which
enable said probe to act as a conduit for receipt and transfer of a
fluid specimen supplied thereto under a slight pressure, which acts
as a driving force, to fill the syringe 10; and (c) a magazine, or
feed tray, for transporting fluid specimens to a location for
pick-up by the probe 51 for delivery to the syringe 10. These
several subassemblies, and their function, are described more
explicitly in the following paragraphs.
The syringe 10 is constituted generally of a pair of contiguous
tubular members comprising a relatively large diameter rearward
section 20 and a smaller diameter forward section 11, for
convenience in manufacture. The rearward section of the syringe is
constituted as a double acting cyliner-piston unit 20 with an air
inlet 21 leading into the forward end of the chamber and an air
inlet 22 leading into the rearward end of the chamber. The air
inlets 21, 22 are provided with flexible hose connections. The
forward end of the chamber is provided with a tubular shaped seal
or packing 23 through which the forward portion of the shaft of the
piston 13 is extended, this hermetically sealing and isolating the
smaller diameter forward section 11 from the rearward section 20.
The forward end of the piston 13, which always remains and travels
within the forward section 11 of syringe 10, is covered or capped
with a resilient material, preferably Teflon, constituting a
sealing head 14. A preferred method of forming seals on the forward
end of movable plungers of this type is described by reference to
U.S. Pat. No. 3,577,850 herewith incorporated by reference. A
plunger stop assembly 25, of adjustable character, is located at
the rearward end of the chamber and within the path of travel of
the piston 13 of cylinder piston unit 20. The function of plunger
stop assembly 25 is to permit piston 13 to traverse a
predetermined, or pre-set, length of the chamber of double-acting
cylinder piston unit 20.
The plunger stop assembly 25 is constituted of a tubular end plug
26 provided with a forward externally threaded shank portion 27
which mates and is threadably engaged with internal threads located
within the end wall forming the chamber of the double-acting
cylinder piston unit 20. A relatively small diameter, internally
threaded tubular section 28 is projected through the axial opening
of the plug 26, is hermetically sealed therein via an O-ring 29.
The tubular section 28 is rotatably mounted within the said axial
opening, though it is not movable in an axial direction. A threaded
shaft 19, preferably provided with a perforated cylindrical shaped
head 24, is movable along the axis of the chamber on rotation of
the knob or plug 26 such that the distance which the plunger 13 is
free to traverse can be adjusted or preselected. It will thus be
observed that the distance between the rearward face of tubular
packing 23 and the forward face of head 24, as well as the
thickness of piston head 18 of piston 13, determine the distance of
travel of plunger 13 within the chamber of the smaller diameter
forward section 11 of the syringe 10, and that such distance can be
readily set by rotation of tubular member 28 which lengthens or
shortens the distance between the forward face of head 24 and the
rearward face of seal 23, by movement of head 24 as the threaded
shaft 19 is moved into or out of tubular section 28 due to the
threaded engagement between these members. It will be observed that
the plunger 13 is reciprocated within the limits set by injection
of air via line 22 into the rearward side of the cylinder piston
unit 20 to drive the piston 13 forward, and by injection of air via
line 21 into the forward side of the cylinder piston unit 20 to
move piston 13 rearwardly.
The smaller diameter tubular forward section 11 of the syringe 10
is generally constructed of transparent plastic or glass, and
optionally scribed with indicia representative of the interval
volume. The volume of the chamber formed within the tubular barrel
11 is exaggerated in the drawings for clarity and, of course, can
be varied in size depending upon the volume of specimen to be
accurately measured and delivered, e.g., as where the specimen is a
liquid or gas. One method of varying the volume of the chamber
within barrel 11 is by adjustment of the length of stroke of the
plunger, as suggested via adjustment of the plunger stop assembly
25. A cannula or needle 12 is fixed within the forward wall or upon
the forward end of the barrel 11 by various means well known to the
art. The needle 12 can thus be snugly fitted into the forward end
of the barrel or smaller diameter tubular forward section 11
through an opening made in the forward wall, and an air-tight seal
provided about the annulus between the outer wall of the needle 12
and well of the barrel 11 by means of a tubular packing or seal 17.
The needle 12, provided with a forward opening 16, is extendable
through horizontal opening 53 of the housing 60, and is
communicable, in proper position, with the vertical opening 54 via
their intersection (or communicating channel).
The syringe 10 is, in its entirety, affixed via a mounting bracket
32 on the forward end of piston 31 of the double-acting
cylinder-piston unit 30, which can be secured via mounting brackets
(not shown) upon the wall of a housing (not shown). The
double-acting cylinder piston unit 30 thus includes the usual
hollow air-tight casing (or enclosing wall) 36, with enclosing end
walls 37, 38, and air inlet-outlet openings 33, 35. The syringe 10
is reciprocably movable along a fixed horizontal path via
reciprocation of plunger 31. Forward movement of the piston 31 is
accomplished by injection of fluid (e.g., air) into the rearward
end of the cylinder-piston unit 30 via inlet 33, the fluid
impinging upon piston head 34 of piston 31 causing the entire
syringe 10 to be thrust forward, this causing passage of the needle
12 through the opening 53 of housing 60, this producing insertion
of the dispensing end of the needle 12 through a septum or other
type of inlet as for sample injection in a modern analytical
instrument. Rearward movement of the piston 31 by injection of
fluid (e.g., air) into the forward end of the unit via inlet 35
again impinges upon piston head 34 to move the syringe 10 in the
opposite direction, this causing withdrawal of the needle 12 from
the sample inlet 90.
The injector feed assembly B comprises a double-acting cylinder
piston unit 50, inclusive of a piston or probe 51, the forward
portion of which is mounted and reciprocable within a tubular
shaped housing 60. The probe 51 is hollow or tubular, at least in
part, to serve as a conduit for receipt and transfer of a fluid
specimen, supplied thereto by pressurizing means described
hereafter, to fill the syringe 10. In the embodiment described by
reference to FIG. 1, and associated figures, the injector feed
assembly B is vertically oriented, as contrasted with the
horizontal orientation of the syringe assembly A. Generally, the
double-acting cylinder piston unit 50 and tubular housing 60 are
formed or fabricated as a unitized assembly, and mounted within a
main housing (not shown) via appropriate fastening means. It will
be observed, in general, that the probe 51 is reciprocable and can
be moved or projected downwardly through the complete length of the
axial opening 54 of tubular housing 60, through the opening 55 of a
mounting plate 56 of a housing (not shown), for penetration of the
septum 81 of a specimen filled vial 82. The probe 51 is provided
with various openings 64, 65, 66 to enhance its utility to serve as
a conduit for pick-up and transfer of fluid, and means are provided
for pressurizing the fluid contents of the vial 82 so that fluid
from a vial 82 can be picked up by the probe 51 and conveyed
upwardly for delivery to the syringe 10.
The double-acting cylinder piston unit 50, like double-acting
cylinder piston unit 30, also includes an enclosing side wall 52,
an enclosing upper end wall 57, and an enclosing lower end wall
formed by the upper face of tubular member 60. An O-ring 58 is
provided to more effectively seal the lower end of the unit 50 and
air inlet-outlet openings 61, 62 are provided for reciprocation of
probe 51, via alternate impingement of air on the opposite faces of
piston head 59. A safety line 63 is optionally provided to serve as
an escape route for air which might escape from cylinder-piston
unit 50, as in the situation of a worn or leaky seal, e.g., O-ring
58.
A chamber 70, with its inlet means 71, located within the tubular
housing 60 provides a preferred means of transmitting a
pressurizing inert or non-reactive fluid, e.g., air, nitrogen, or
the like, to a vial 82 to effect transfer of the fluid specimen
therefrom to probe 51 for pick-up and delivery of same to syrine
10. Suitably, for manufacturing convenience, the tubular member 60
is formed of two sections 60.sub.A, 60.sub.B, and chamber 70 is
formed by these members. Chamber 70 is thus formed by fitting
together of the abutting face of member 60.sub.A, 60.sub.B, each of
which contains a cylindrical cut-away section, and the air-tight
character thereof is assured by an inner lining or bushing 7
located between the interface of tubular members 60.sub.A,
60.sub.B. O-rings 72, 73 further assure the air-tight nature of the
fit.
The double-acting cylinder piston unit 50, like doubleacting
cylinder piston units 20, 30, are generally pneumatic, air being
used as the driving medium. Virtually any source of pressurized
fluid, e.g., hydraulic fluid or pneumatic pressure, however, can be
used. The probe 51 of cylinder-piston unit 50 can thus be moved
upwardly via pressurized fluid injected via gas inlet-outlet port
62, and downwardly by injection of pressurized fluid injected via
gas inlet-outlet port 61. When the piston 51 is thrust to its
extreme downward position, by fluid pressure acting against piston
head 59, the lower terminal end of the probe 51 is projected
through the opening 55 in the wall of the lower housing, through a
centrally located opening through a septum cap 81 of a vial 82 for
pick-up of a fluid specimen, delivered into position by action of a
feed tray or magazine 80.
In the several embodiments of this invention, a magazine or feed
tray 80 is provided for conveying fluid specimen-containing vials
82 in seriatim to a location beneath the opening 55 or housing 56
for pick-up by the probe 51. The vials 82 are of open screw top
type, sealed with a elastomer septum 81 to prevent leakage or
contamination and to permit pressurization. As the vials 82 are
moved into position beneath the opening 55, the probe 51 can be
moved downwardly and projected through the opening 55 at the bottom
of housing 56 to pass through the open caps and penetrate the
septum of the vials 82 for pick-up of the fluid specimen.
An operating cycle is described by reference to FIGS. 2 through 8,
these figures depicting a series of views describing the filling,
injecting, cleaning and purging of syringe 10. The timed sequence
can be repeated ad infinitum, as follows:
a. Referring first to FIG. 2, probe 51 is pushed downwardly from an
upward starting position (FIG. 1) by pressurized air which enters
into the chamber of the cylinder-piston unit 50 via the
inlet-outlet port 61 to impinge on piston head 59. Simultaneously,
air is exhausted via air inlet-outlet port 62. The probe 51 is side
vented in three locations, and the side vent openings 64, 65, 66
are communicated one with the other by an axial opening through the
probe. The septum 81 of the air-tight vial 82, located between the
threaded cap 83 and the upper shoulder of the glass vial 84, is
penetrated by the sharp, or pointed, end of probe 51. As the upper
side vent opening 64 passes into the chamber 70 formed within
tubular member 60.sub.A, 60.sub.B, to which a gas is admitted via
the pressure gas inlet 71, gas enters into side vent openings 64,
65 and flows downwardly through the axial opening through hollow
probe 51 to exit via the lower side vent opening 66 and into the
vial 82, pressurizing the latter.
b. Prior to the time that probe 51 has reached its most downward
position, as shown by reference to FIG. 3, the chamber 70 and
pressure gas inlet 71 are no longer open to the upper side vent
openings 64, 65 of the probe 51. Rather, the upper side vent
openings 64, 65 of the probe 51, at the maximum downward position
of piston 51, open to the valved drain line 67 and horizontal
opening 53, the latter communicating openings 65 with the axial
opening at the dispensing end of needle 12. At this point in time,
fluid from vial 82 flows through the axial opening through probe 51
and (plunger 13 of the syringe 10 being withdrawn creating a
vacuum) into the needle 12. On terminating of the downward movement
of probe 51, inlet-outlet port 62 is in fully vented position.
c. Reference is now made to FIG. 4 of the drawings. Air is injected
via line 22 into the rearward side of cylinder-piston unit 20, the
air passing through perforated head 24 to impinge on plunger head
18 of plunger 13, driving the plunger 13 forward. Fluid specimen is
discharged from the dispensing end of needle 12, entering via side
opening 65 into the axial opening of probe 51 whereon it is
discharged via side opening 64 into valved drain line 67. Suitably,
the opening 67 is sized and valved such that fluid is discharged
therefrom rather than passing downwardly through the axial opening
of the probe 51 to serve as contamination.
d. Referring to FIG. 5, the direction of movement of plunger 13 is
reversed by passage of air into inlet-outlet line 21, with
simultaneous venting of inlet-outlet line 22, air impinging on head
18 of plunger 13 to drive it again to the rear, its motion
terminating on impingement against perforated head 24.
Reciprocation of the plunger 13 at this time is generally effected
to flush and clean the needle 12, the contaminated fluid being
discharged through drain line 67. Generally, a plurality of
reciprocations are employed to thoroughly clean the needle 12, the
last quantity of liquid being held for injection, as shown by
reference to the said FIG. 5.
e. Referring to FIG. 6, the probe 51 is next moved away from its
position blocking horizontal opening 53, to permit passage of
needle 12. Probe 51 is thus lifted clear of opening 53 by injection
of air into inlet-outlet opening 62 of cylinder-piston unit 50,
while simultaneously inlet-outlet opening 61 is vented, air
impinging upon the under face of plunger head 59 driving probe 51
upwardly. The injector feed assembly A portion of the automatic
fluid injector is now repositioned as shown by reference to FIG.
1.
f. The entire syringe 10, as shown by reference to FIG. 7, is now
moved forward by air injected via inlet-outlet port 33 into
cylinder-piston unit 30, while inlet-outlet line 35 is in vented
position, the air impinging upon the piston head 34, causing the
piston 31 to be thrust forwardly and cause the needle 12 to be
inserted into inlet 90 of an analytical instrument, e.g., a gas
chromatograph.
g. Referring to FIG. 8, air to inlet-outlet port 22 (not shown)
drives plunger 13 to its extreme forward position, the head 14
thereof transversing the length of the chamber 11 to inject the
liquid specimen into the inlet 90. Simultaneously, carrier gas is
admitted via line 91 to aid in the injection of the fluid specimen
into the instrument.
h. The plunger 13 is next repositioned by admission of air into
inlet-outlet port 21, of cylinder-piston unit 20, while
inlet-outlet port 22 is vented, the plunger 13 of syringe 10 being
repositioned as shown by reference to FIG. 1.
i. The syringe 10 is next repositioned by injection of air into
inlet-outlet port 35, of cylinder-piston unit 30, while
inlet-outlet port 33 is vented, the entire syringe 10 being
repositoned as shown by reference to FIG. 1.
A second preferred form of this invention is depicted by reference
to FIGS. 9 through 11, this embodiment including essentially the
same overall combination of (a) a syringe assembly A, (b) an
injector feed assembly B, and (c) a magazine or feed tray C, as
generally described by reference to FIGS. 1 through 8. In fact, in
this embodiment, essentially the same injector feed assembly B and
magazine, or feed tray, C can be used, as desired.
Referring specifically to FIG. 9, the drawing thus shows the same
injector feed assembly B as described by reference to FIGS. 1
through 8, the only exception being that probe 51 contains one less
opening (opening 64 is omitted). The magazine or feed tray is, or
can be, identical to that formerly described by reference to the
preceding figures. The cylinder-piston unit 30, upon the piston 31
of which the syringe 100 is mounted, is also the same as that
described by reference to the preceding figures. The syringe 100,
however, includes features not present in syringe 10, previously
described by reference to FIGS. 1 through 8.
The syringe 100 includes, at the front section thereof, a barrel
111, the usual plunger 113, provided with a front seal, or sealing
head 114, cannula or needle 112 mounted in the forward end of the
barrel, and seal 117 which prevents leakage of fluid around the
needle annulus. In this instance, the barrel 111 is provided with
an opening or cavity 109 of larger diameter than that of the
plunger 113, or plunger head 114. A side outlet 108 is located
downstream of the said cavity 109.
The rearward portion of syringe 100 comprises a double-acting
cylinder piston unit 120, the unit being constituted of a tubular
barrel, of relatively large diameter as contrasted with the forward
barrel 111 to which it is affixed, and hermetically separated by a
tubular seal 123. The plunger 113 also serves as a piston of the
cylinder piston unit 120 and is slidable within the axial opening
of the seal 123, the enlarged head portion 118 thereof being
contained within the larger diameter tubular barrel 120. The
distance over which the plunger 113 is free to move can be preset
by virtue of the plunger stop assembly 125 very similar in
structure and function to plunger stop assembly 25 described by
reference to FIGS. 1 through 8. The plunger stop assembly 125 thus
includes a perforated head or stop member 124 rigidly mounted on
the forward end of an externally threaded shaft 119, the latter of
which is threadably engaged with an internally threaded tubular
member 128, rotatably mounted within an axial opening through an
end plug 126. The plug 126, it will be noted, is provided with an
externally threaded portion of reduced diameter which mates with
internal threads inside the end wall of member 120 to which it is
firmly secured, and leakage of air around the annulus between the
external wall of tubular member 128 and the inside wall forming the
axial opening through plug 126 is prevented by an O-ring seal 129.
Unlike plunger adjustment stop 25 depicted by reference to FIGS. 1
through 8, however, a helical coil spring 107 encircles the shaft
119 and rotatable tubular member 128, and it is seated and
tensioned between the rearward face of perforated head 124 and the
forward face of plug 126. Morever, unlike plunger stop assembly 25,
the plunger stop assembly 125 is axially displaceable, and with the
spring 107 provides an extra function which shall subsequently be
described, when actuated in desired sequence by pressurized fluid,
e.g., air, introduced into inlet-outlet ports 121, 122.
The syringe 100, containing the enlarged opening or cavity 109, is
superior in certain respects to the syringe 10 described by
reference to FIGS. 1 through 8, and to the syrine described in
copending application Ser. No. 223, 663, supra. It provides better
annular flow of the fluid specimen around plunger head 114, such
that there is less contamination from previously injected
specimens. Better flushing results, and less turbulence is created
on withdrawal of the plunger 113. Seal wear is lessened, this
resulting not only in a more permanent fit, but also results in
less contamination. There is less need for close plunger
tolerances, and manufacturing is less complicated.
In operation, referring again to FIG. 9, the plunger 113 is shown
in widhdrawn position as pre-set for recipt of a fluid specimen
from a vial 82. The vial 82, having been previously pressurized by
passage of the opening 65 of probe 51 through chamber 70, transmits
fluid via opening 66, the axial opening through the probe, and
opening 65 into the opening at the dispensing end of needle 12 to
fill the forward end of barrel 111, while the plunger 113 is
further withdrawn caused by injection of air via inlet-outlet port
121, with simultaneous venting of inlet-outlet port 122 (FIG. 10).
The helical spring is thereby compressed, the tip 114 of plunger
113 is moved back into the enlarged opening or cavity 109 and fluid
specimen flows past the tip 114 to purge the needle 12 and forward
end of the chamber 111. contaminated fluid egresses via side
opening 108, and is passed to waste. On completion of the cleaning
purge, inlet-outlet port 121 is vented (FIG. 11) thus releasing the
pressure applied upon the forward face of head 118 of plunger 113
so that the latter is thrust forward to trap an accurately measured
quantity of fluid specimen forward of the plunger tip 114, which
specimen is now ready for injection via steps already described by
reference to FIGS. 1 through 8.
Certain modifications can also be made in the injector feed
assembly B, in association with changes made in the magazine, or
feed mechanism C, to pressurize individual vials via different
means than shown by reference to the preceding figures, particular
reference being made to FIGS. 12 and 13. The injector feed
assemblies B described by these figures are thus essentially the
same as described by reference to preceding FIGS. 1 through 11,
except that pressure chamber 70, with its air inlet port 71, has
been completely eliminated. The vials are pressurized by different
means.
Referring to FIG. 12, it will be observed that when opeinings 64,65
of probe 51 are aligned with the horizontal opening 53 and drain
line 67, and a fluid specimen filled vial 182 constituted of a
flexible, elastomeric, plastic or plastic-like material, is
positioned by a movable feed tray and the septum 181 thereof
pierced by probe 51, a pair of opposed rotating roller members
191,192 with protruding surfaces 193,194 force the walls of the
vial 182 inwardly pressurizing the contents of the vial 182 so that
the fluid specimen is forced into side opening 66, into the axial
opening of probe 51, which fluid exits via opening 65 into the
dispensing end of needle 12 (or 112). Reciprocation of the plunger
113 (not shown in this figure) flushes the needle 12 (or 112),
discharging the contaminated fluid specimen through line 67, anmd
readies the syringe for injection of an accurately meansured fluid
specimen.
A slightly different modification of the magazine or feed mechanism
is shown by reference to FIG. 13, as contrasted with FIG. 12,
although the injector feed assembly B is the same. A fluid specimen
filled flexible walled vial 195, of fluted cross section, is herein
shown carried on feed magazine, or tray 180. The upper portion of
the vial 195 is flanged and fitted within a small diameter opening,
and held therein by clamps 196,197. The lower circular portion of
the feed tray 180 is open, below the location of the vial, and a
hydraulic piston element 198 of a cylinder piston unit 199 can
apply force on the bottom of vial 195 to pressurize the fluid
therein by squeezing in or collapsing the walls of the septum vial
195. In accordance with this means also, fluid specimen if forced
into opening 66 of probe 51, to exit via opening 65 into the
dispensing end of needle 12 (or 121). After purging of the excess
contaminated fluid specimen via drain line 67, the syringe is ready
for injection of an accurately meansured quantity of the
specimen.
The injector feed assembly B can be further modified, and
simplified, as shown by reference to FIGS. 14 and 15. Referring to
FIGS. 14 and 15, there is shown another embodiment wherein a pair
of hollow probes 151.sub.A, 151.sub.B are mounted within a single
movable block 160.sub.A, which in effect substantially replaces the
upper section 60.sub.A of housing 60, as depicted, e.g., by
reference to FIG. 1. The block 160.sub.A, containing hollow probes
151.sub.A, 151.sub.B, is mounted on the terminal end, via
appropriate connection (e.g., by treadable engagement), with a
reciprocable piston 151.sub.C of doubleacting cylinder piston unit
150. Double-acting cylinder pistion unit 150 is comprised of the
usual barrel, formed by an enclosing side wall 152, enclosing end
walls 157.sub.A, 157.sub.B providing an hermetic seal, and
inlet-outlets 161,162 which admit pressurized fluid, e.g., air, in
alternate sequence for impingement on either face of piston head
159 to reciprocate the piston 151.sub.C, and consequently the
probes 151.sub.A, 151.sub.B.
The lower fixed block 160.sub.B corresponds generally with the
lower section 60.sub.B of housing 60, as shown by reference to FIG.
1. The fixed block 160.sub.B is thus provided with a horizontal
opening 153 which is in axial alignment, and open communication,
with the passageway leading into the inlet 90 of the analytical
instrument, so that an injection of a fluid specimen can be readily
made by needle 12, and swept into the instrument by carrier gas
admitted via line 91. It will be observed that the axial opening
153, unlike the emobdiments previously described, is in a different
plane from the vertical opening 154.sub.A through which the probe
151.sub.A is projected, openings 153, 154.sub.A being communicated
one with the other via a short channel 154.sub.B. The second hollow
probe 151.sub.B, the upper teminal end of which is connected with a
gas inlet 163, is projected through a second vertical opening
154.sub.C within block 160.sub.B, and both probes 151.sub.A,
151.sub.B extend through the slot or opening 54 of plate 56.
In operation, air enters via line 161 into cylinder piston unit
150, impinging upon the upper face of piston head 159, driving the
piston 151.sub.C, and consequently the pair of probes 151.sub.A,
151.sub.B, downwardly, as shown by direct reference to FIG. 14. The
probes 151.sub.A, 151.sub.B penetrate the septum 81 of the fluid
specimen containing vial 82, positioned by feed tray 80. Air, under
pressure, is fed via line 163 through the axial opening of probe
151.sub.B, the air exiting into the vapor space of vial 82 via the
side opening 164, building up pressure. Fluid specimen from vial 82
is forced into opening 165 of probe 151.sub.A, the fluid rising
through the axial opening of probe 151.sub.A and exiting through
opening 166, at the upper portion of probe 151.sub.A. The fluid
specimen then passes through channel 154.sub.B and enters into
passageway 153 wherein it is fed into needle 12. On pulsing air via
line 162 into the double-acting cylinder piston unit 150, probes
151.sub.A, 151.sub.B are raised to their uppermost position, in
which position opening 165 of probe 151.sub.A is in alignment with
flush line 167.
A preferred form of this invention is characterized by reference to
FIGS. 16 through 19, these figures depicting yet another form of
syringe assembly sueful in the same overall combination which
includes (a) syringe assembly A, (b) injector feed assembly B, and
(c) magazine, or feed tray, C as generally described by reference
to any of FIGS. 1 through 8, FIGS. 9 through 11, and inclusive also
of FIGS. 12 and 13, and FIGS. 14 and 15.
In the syringe 200, depicted by reference to FIGS. 16 through 19,
the plunger itself is hollow, providing a dual function serving
both as a means for positive expulsion of an accurately measured
fluid specimen into, e.g., the inlet of an analytical instrument,
and also for conveyance of the fluid specimen through the syringe
interior for cleaning and purging of the instrument. Referring
generally to the figures, particularly to FIG. 16, it will be
observed that the forward portion of the syringe 200 is comprised
generally of the usual barrel 211, on the forward terminal end of
which is provided a cannula or needle 212, and within the barrel of
which is fitted a reciprocable plunger 213; in this instance,
however, a hollow plunger. The rearward portion of the barrel 213
is contained within a tubular member 210. Spacer bars 208,209
separate the forward portion of the syringe 200 from a paired
series of double-acting cylinder piston units.
Referring to the paired series of double-acting cylinder piston
units, it will be observed that the most rearward double-acting
cylinder piston unit 275 includes the usual barrel 276, formed by
an enclosing side wall, and enclosing end walls 277,278 with
inlet-outlets 279,281 leading into the hermetically sealed
enclosure. The forward double-acting cylinder piston unit 250 is
also comprised of an enclosing side wall, or barrel 251, with
enclosing end walls 252,277, provided with inlet-outlet ports
253,254. The end wall 277, it will be noted, provides a common wall
between cylinder piston units 250,275. The end wall 277 is provided
with an axial opening within which the reciprocable piston 282 is
fitted, the piston 282 being affixed to a piston head 283 on which
pressurized fluid, e.g., air, acts for reciprocation of the piston
on admission of air in alternating sequence via inlet-outlet ports
279,281. The cylinder piston unit 250, it will be observed, is also
provided with a hollow piston 255, affixed at one end to piston
head 256, this piston 255 also being reciprocable within the axial
opening of wall 252 through which it is extended via action of
pressurized fluid, e.g., air, admitted in alternate sequence via
inlet-outlets 253,254. It will be specifically observed that piston
282 is projected through an axial opening through piston head 256,
and an axial opening through hollow piston 255. Each of pistons
255,282 are independently reciprocable, the former being actuated
and reciprocated by reciprocated by pressurized gas fed into the
unit via lines 279,281.
The rearward end of hollow plunger 213 is externally threaded, and
threadably engaged, via an internally threaded central tap within
axial opening 215, to the forward end of a slidable tubular member
216. The opposite end of slidable tubular member 216 is also
externally threaded and threadably engaged, via an internally
threaded cap 217, and affixed nut 218, to the forward terminal end
of the externally threaded hollow piston 255. Thus, the tubular
member 216 and hollow piston 255 are joined one to the other, or
unitized such that movement and reciprocation of hollow piston 255
produces a corresponding movement of tubular member 216. A section
of the rearward side of axial opening 215, of tubular member 216,
is enlarged to accomodate an enlarged cylindrical shaped stop 284,
located on the forward end of reciprocable piston 282. It will be
observed that a segment of reduced diameter, of piston 282, extends
forward of the stop 284, and is provided with a sealing head or cap
285. The forward terminal end of hollow plunger 213 is also
peripherally sealed by a head or cap 214. In the position shown by
reference to FIG. 16, the capped end of plunger 282 blocks the
lateral or side opening 219 of tubular member 216.
In operation, referring to FIG. 17, pressurized air is injected via
line 286,253,281 into cylinder piston units 250,275, while lines
254,279 are vented, both of pistons 255,282 being driven to the
rear by impingement of air against the inside faces of piston heads
256,283. The rearward movement of piston 255 moves tubular slide
216 to its extreme rearward position, and retracts plunger 213,
this occuring as nut 218 impinges against the forward face of end
wall 252. The rearward movement of piston 282 withdraws the capped
head 285 rearward of lateral opening 219 of tubular slide 216 so
that a fluid specimen is drawn via needle 212 into barrel 211, the
fluid specimen passing through the axial opening of hollow plunger
213 and discharging through the lateral opening 219 of slide 216.
The rearward movement of plunger 282 is terminated on contact of
stop 284 with the inside face of cap 217.
Upon completion of the purging and cleaning step, pressurized air
is injected via line 279, into cylinder piston unit 275, at
pressure slightly greater than that introduced into the cylinder
piston unit 275 via line 281, the air impinging on the rearward
face of plunger head 283, pushing the plunger 283 forward a limited
amount until the stop 284 is seated, and its forward motion
blocked, against the forward wall of the enlarged portion of axial
opening 215, at which time the tip of the capped head 285 of
plunger 282 abutts the rearward end of plunger 213. The flow of
fluid specimen through needle 212, barrel 211, plunger 213, and
into lateral opening 219 is thus abated. At this time, the needle
212 of syringe 200 is inserted into the inlet of an analytical
instrument, e.g., inlet 90, in the same manner described by
reference to the preceding figures.
To effect injection of the accurately measured fluid specimen,
pressurized air is admitted via line 254, 279, while lines 253,
281, 286 are vented, such that the tubular slide 216, and hollow
plunger 213 are driven forward to expel the fluid specimen via
needle 212.
It is apparent that various substitutions, modifications and
changes, such as in location, or in the absolute or relative
dimensions of the parts, materials used and the like, can be made
without departing the spirit and scope of the invention as will be
apparent to those skilled in the art.
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