U.S. patent application number 11/458283 was filed with the patent office on 2006-11-23 for method and apparatus for injecting fluid into animals and disposable front loadable syringe therefor.
This patent application is currently assigned to LIEBEL-FLARSHEIM COMPANY. Invention is credited to Paul E. Dieterlen, Frank M. Fago, James H. Goethel, Charles Neer.
Application Number | 20060264744 11/458283 |
Document ID | / |
Family ID | 24860794 |
Filed Date | 2006-11-23 |
United States Patent
Application |
20060264744 |
Kind Code |
A1 |
Neer; Charles ; et
al. |
November 23, 2006 |
Method and Apparatus for Injecting Fluid into Animals and
Disposable Front Loadable Syringe Therefor
Abstract
An animal fluid injector replaceable syringe and method of
replacement of the syringe in the injector are provided in which
the syringe is loadable and unloadable into and from the injector
through the front of the injector, thereby permitting replacement
without retraction of the syringe plunger drive or disconnection of
the injection tubing. A mechanism in the injector, which includes,
for example, a key on cam ring operated by a lever with one hand of
an operator, interacts with structure such asymmetrically spaced
notches on the back end of the syringe to, for example, rotate the
syringe and simultaneously translate or rotate a coupling on the
syringe plunger into and out of engagement with jaws of the plunger
drive in the injector.
Inventors: |
Neer; Charles; (Cincinnati,
OH) ; Fago; Frank M.; (Mason, OH) ; Dieterlen;
Paul E.; (Morning View, KY) ; Goethel; James H.;
(Cincinnati, OH) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER
441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
LIEBEL-FLARSHEIM COMPANY
2111 East Galbraith Road
Cincinnati
OH
|
Family ID: |
24860794 |
Appl. No.: |
11/458283 |
Filed: |
July 18, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10730302 |
Dec 8, 2003 |
7081104 |
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11458283 |
Jul 18, 2006 |
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|
09970289 |
Oct 2, 2001 |
6659979 |
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11458283 |
Jul 18, 2006 |
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|
08924017 |
Aug 29, 1997 |
6315758 |
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11458283 |
Jul 18, 2006 |
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08455984 |
May 31, 1995 |
5738659 |
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11458283 |
Jul 18, 2006 |
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08158765 |
Nov 30, 1993 |
5456669 |
|
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11458283 |
Jul 18, 2006 |
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07881782 |
May 11, 1992 |
5279569 |
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11458283 |
Jul 18, 2006 |
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07712110 |
Jun 7, 1991 |
5300031 |
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11458283 |
Jul 18, 2006 |
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Current U.S.
Class: |
600/432 ;
604/151 |
Current CPC
Class: |
A61M 2250/00 20130101;
A61M 5/14546 20130101; A61M 5/1458 20130101; Y10S 128/01 20130101;
A61M 5/14566 20130101 |
Class at
Publication: |
600/432 ;
604/151 |
International
Class: |
A61M 5/00 20060101
A61M005/00 |
Claims
1. A disposable replacement syringe for a front loadable injector
for injecting liquid into an animal, where the injector has a
syringe receiving opening on the front thereof and has syringe
mating structure circumferentially displaced inside the opening,
the disposable syringe comprising: a hollow body having a
cylindrical tubular wall, a central longitudinal axis, a closed
forward end having a discharge outlet therein, and an open rearward
end; a plunger snugly slidable within the hollow body in direct
contact with the inside of the tubular wall and having a rearwardly
facing drive engaging coupling thereon; an annular flange extending
outwardly from the hollow body and monolithic therewith, the
annular flange lying in a plane perpendicular to the longitudinal
axis of the body; and locking structure spaced longitudinally a
fixed distance rearwardly from the annular flange monolithic with
and extending radially from the tubular wall of the body a distance
smaller than the outward extension of said annular flange, the
locking structure being configured to engage the mating structure
internal to the opening on the front of the injector to lock the
syringe thereto and to thereby urge the annular flange against the
opening.
2. The disposable replacement syringe of claim 1 for use with an
injector having a pressure jacket extending forwardly therefrom,
the jacket having a cylindrical bore therein, the opening of the
injector being the hollow bore of the jacket, and wherein the
mating structure is a plurality of internal sections fixedly
located on the inside of the jacket, wherein: the syringe locking
structure comprises radially extending mating sections positioned
in a plane perpendicular to the axis of the body of the syringe so
as to align with internal sections on the jacket when the syringe
is inserted in the jacket and to lock the syringe to the
jacket.
3. The disposable replacement syringe of claim 2, wherein: the
annular flange is in the form of a continuous annular ring
surrounding the body; and the locking structure forms means for
sealably urging the annular flange against the jacket when the
syringe is locked to the jacket to inhibit leakage of spilled fluid
into the injector.
4. The disposable replacement syringe of claim 1, wherein: the
annular flange extends outwardly from the forward end of the hollow
body.
5. The disposable replacement syringe of claim 1, wherein: the
locking structure extends radially outwardly from the tubular wall
adjacent the forward end of the hollow body.
6. The disposable replacement syringe of claim 1, wherein: the
locking structure comprises a four equally spaced sections lockable
to internal sections of the mating structure on the injector upon
rotation of 45 degrees about the axis.
7. The disposable replacement syringe of claim 1, wherein: the
locking structure comprises four equally spaced sections each
spanning not more than 45 degrees about the axis.
8. The syringe of claim 1, for use with an injector having a
tubular member extending forwardly from the front thereof and
having a cylindrical bore therein forming the opening at the front
of the injector, the tubular member having a circular front end
lying in a plane; and further comprising: means, including the
locking structure, for urging the annular flange rearwardly against
the front end of the tubular member.
9. The syringe of claim 1 for use with an injector having a
continuous rim surrounding and forming the periphery of the
opening, and wherein: the annular flange is in the form of a
continuous annular ring; and the locking structure urges the
annular flange rearwardly against the syringe receiving opening
when the syringe is locked to the injector to form a seal with the
opening to inhibit leakage of spilled fluid into the injector.
10. The disposable replacement syringe of claim 1, wherein: the
locking structure includes a plurality of radially extending mating
sections.
11. A front loadable power injector for injecting liquid into an
animal comprising: an injector having a housing, a syringe
receiving opening and a plunger driving ram mounted in the housing
and extendable along an axis through the opening; a syringe having
a hollow body having a cylindrical tubular wall, a central
longitudinal axis, a closed forward end having a discharge outlet
therein, an open rearward end, a plunger snugly slidable within the
hollow body in direct contact with the inside of the tubular wall
and having a rearwardly facing drive engaging coupling thereon, an
annular flange monolithic therewith extending around and outwardly
from the hollow body and perpendicular to the longitudinal axis of
the body, and locking structure monolithic therewith spaced
longitudinally rearwardly from the annular flange and extending
radially from the tubular wall of the body a distance smaller than
the outward extension of said annular flange; the locking structure
being sized to engage the injector at the opening so as to lock the
syringe to the injector to thereby urge the annular flange against
the opening.
12. The injector of claim 11 wherein: the injector has a pressure
jacket extending forwardly from the housing, the jacket having a
cylindrical bore therein, the syringe receiving opening of the
injector being in the bore of the jacket; and the syringe is locked
to the opening of the jacket.
13. The injector of claim 12 further comprising: means including
the locking structure for sealably urging the annular flange
against the jacket.
14. The injector of claim 12 wherein: the jacket has a circular
front end lying in a plane; and the annular flange is sealably
urged rearwardly against the front end of the jacket.
15. The injector claim 11 wherein: the annular flange is in the
form of a continuous annular ring lying in a plane and surrounding
the hollow body; and the ring is configured such that, when urged
against the opening, a seal is formed to inhibit leakage of spilled
fluid into the injector.
16. The injector claim 11 wherein: the annular flange extends
outwardly from the forward end of the hollow body; and the injector
includes a cylindrical member extending forwardly from the injector
housing and having a hollow bore therethrough, the syringe
receiving opening being at an end of the bore remote from the
injector housing.
17. The injector of claim 11 wherein: the locking structure extends
radially outwardly from the tubular wall adjacent the forward end
of the hollow body of the syringe.
18. The injector of claim 11 wherein: the locking structure and
mating structure for engagement therewith at the opening each
include four equally spaced thread sections; and the sections are
configured to mutually engage upon rotation of the syringe of 45
degrees.
19. The injector of claim 18 wherein: the locking structure and
mating structure for engagement therewith at the opening each
include four equally spaced thread sections spanning not more than
45 degrees.
20. The injector of claim 11 wherein: the injector housing has a
tubular member extending forwardly from the front thereof and
having a cylindrical bore therein forming the syringe receiving
opening; the tubular member has a circular front end lying in a
plane; and the annular flange is sealably urged rearwardly against
the front end of the tubular member.
21. The injector of claim 11 wherein: the locking structure and the
mating structure therefor at the opening each include equally
spaced thread sections; and the sections are configured to mutually
engage upon rotation of the syringe of 45 degrees.
22. The injector of claim 11 wherein: the locking structure and the
mating structure therefor at the opening each include equally
spaced thread sections spanning not more than 45 degrees.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No.
10/730,302 filed Dec. 8, 2003, now U.S. Pat. No. 7,081,104, which
is a divisional of application Ser. No. 09/970,289 filed Oct. 2,
2001, now U.S. Pat. No. 6,659,979, which is a divisional of
application Ser. No. 08/924,017, filed on Aug. 29, 1997, now U.S.
Pat. No. 6,315,758, which is a continuation of Ser. No. 08/455,984
filed May 31, 1995, now U.S. Pat. No. 5,738,659, which is a
continuation of Ser. No. 08/158,765 filed Nov. 30, 1993, now U.S.
Pat. No. 5,456,669, which is a divisional of Ser. No. 07/881,782
filed May 11, 1992, now U.S. Pat. No. 5,279,569, which is a
divisional of Ser. No. 07/712,110 filed Jun. 7, 1991, now U.S. Pat.
No. 5,300,031, all of which are hereby incorporated by reference
herein.
FIELD OF THE INVENTION
[0002] The present invention relates to injectors and more
particularly to disposable replacement syringes for animal fluid
injectors.
BACKGROUND OF THE INVENTION
[0003] Injectors are devices that expel fluid, such as contrasting
media, from a syringe and through a tube into an animal. The
injectors are provided with an injector unit, usually adjustably
fixed to a stand or support, having a drive that couples to the
plunger of the syringe to drive it forward to expel fluid into the
tube, or that may be driven rearward to draw fluid into the syringe
to fill it. Usually the syringe is a disposable replacement
type.
[0004] In the injection phase where the plunger is driven forward,
pressures are developed in the syringe that range from, for
example, twenty-five psi for some applications to over 1000 to 1200
psi for other applications. Syringes that will contain fluid under
such pressures are expensive and therefore impractical where the
syringes are to be disposable. Accordingly, many such injectors,
such as angiographic injectors, for example, have been provided
with pressure jackets fixed to the injector units and into which
the syringes are inserted. The pressure jackets contact the outer
surfaces of the syringe to restrain the walls of the syringe
against the internal pressures.
[0005] To hold the syringes in the pressure jackets, the jackets of
the prior art have been configured to surround the front ends of
the syringes to restrain the syringe front wall against forward
acting forces of the drive and the fluid pressure and to hold the
syringe in the jacket. Because the front end of the pressure jacket
is closed, rear loading was necessary, and accessibility thereto
was provided by hinging or rotating the jacket to allow for removal
and replacement of the syringe from the rear. The opening and
reclosing of the injector unit to replace the syringe requires a
certain amount of time, which, in the course of the procedure being
performed, is not wholly desirable.
[0006] Furthermore, while for many years injector units of various
types have been capable of disconnection of the plunger drive from
the drive coupling on the syringe plunger at any position of the
plunger within the syringe, retraction of the drive is typically
required before the syringe can be removed. This is because the
opening of the injector unit to remove and insert the syringe from
the rear requires, for example, a translating or rotating of the
jacket from the axis of the drive, which cannot be achieved if the
plunger drive is extended.
[0007] For example, at the end of an injection procedure, the
syringe plunger typically is forward, as is the plunger drive.
Since, in the prior art injectors that load from the rear, the
pressure jacket is moved through the position that the drive
occupies when extended in order to remove the syringe. Hence, the
syringe cannot be immediately removed without retracting the
plunger drive. Further, the disposable tubing that connects to the
nozzle of the syringe must be disconnected from the syringe in
order to remove the syringe from the jacket. Additionally, when an
empty new syringe is inserted, the drive must be in its retracted
position.
[0008] More often than not, the syringe is inserted empty and
filled by retraction of the plunger with an injection tube
connected to a supply of the fluid that is to be injected. In
addition, before an empty new syringe can be filled, it is
necessary that the plunger be fully forward in the syringe so that
the syringe can be filled by rearward retraction of the plunger. As
a consequence of the need with such prior art injectors to retract
the drive upon loading the syringe, it is then necessary to fully
advance the drive to the position in which it is in engagement with
the plunger and the plunger is in its full forward position. The
drive then engages a coupling on the plunger of the replacement
syringe. This need to retract and advance the drive contributes to
a loss of time in the syringe replacement process.
[0009] Accordingly, there has been a need to more quickly load and
unload disposable replacement syringes in angiographic injectors,
and for injectors and replacement syringes that can accommodate a
more efficient process of syringe replacement.
SUMMARY OF THE INVENTION
[0010] It is an objective of the present invention to provide a
method and apparatus by which replaceable syringes can be more
efficiently loaded into and unloaded from injectors.
[0011] It is a more particular objective of the present invention
to provide an injector, more particularly an angiographic injector,
a replacement syringe therefor, and a method of replacing the
syringe in the injector that provide for more efficient replacement
of the syringes in the injector. It is an additional objective of
the present invention to provide an injector wherein a used syringe
can be removed and a new one inserted in the injector without
retraction of the drive from the pressure jacket, in most
applications. It is a further objective of the invention to allow
for the removal of the used syringe from the jacket without
disconnection of the injector tube from the syringe nozzle.
[0012] It is still a further objective of the present invention to
provide an injector, replaceable syringe and method of syringe
replacement with which the replacement of the syringe can be
achieved with simple motions by the operator or with rapid
operation of injector unit mechanisms.
[0013] An additional objective of the present invention is to
provide an injector and replaceable syringe therefor that will
facilitate control of the orientation of the syringe in the jacket,
and thereby provide for positive, rapid and reliable engagement of
the syringe with locking structure that holds the syringe in the
jacket, engagement of the plunger drive and plunger drive coupling,
or connection of the injection tube to the outlet of the
syringe.
[0014] A further objective of the present invention is to provide
for easy to operate mechanism and reliable locking structure for
locking the syringe in place in the pressure jacket of the
injection unit.
[0015] Another objective of the present invention is to provide an
injector and syringe arrangement that minimizes or eliminates the
probability of spillage from the syringe nozzle flowing into the
injector equipment, and otherwise enhancing the ability to maintain
sterility and cleanliness of the equipment.
[0016] According to the principles of the present invention, there
is provided an angiographic injector having a front end loadable
syringe that can be loaded into and removed from the injector
pressure jacket through an opening that is provided in the front
end of the pressure jacket. To provide this front end loadable
feature, the syringes of the preferred and illustrated embodiments
of the present invention are provided with a front wall that is
pressure restraining, that is, is of sufficient strength to support
the front of the syringe against the expected pressures within the
syringe, and that is securable to the front end of the pressure
jacket so as to complete the pressure restraining enclosure of the
syringe within the pressure jacket and hold the syringe in the
jacket. In one preferred form, this front end of the injector is
formed of a separate pressure restraining cap made of material that
is separate from the front wall of the syringe and may be reusable.
In another preferred form, the cap may be formed integrally of the
front syringe wall. With the cooperating structure of the jacket
and the syringe, restraining of the pressure jacket along the front
and sides of the syringe is provided where the jacket allows for
the replacement of the syringe from the front.
[0017] In one preferred and illustrated embodiment of the
invention, the front end of the syringe locks to the front end of
the pressure jacket through a cooperating engagement of mating
threads on the syringe jacket. The threads include external thread
sections formed at the front end of the pressure jacket and
internal threads formed on an outwardly extending flange or rim of
the front wall of the syringe, preferable on a pressure restraining
cap. Alternatively, other securing or locking structure such as a
clip or an adaptor, for example, may be employed to join the
syringe to the jacket.
[0018] In the preferred embodiment of the present invention, the
threads are engageable in a limited number of angular positions to
thereby predetermine the angular orientation of the syringe in the
pressure jacket. Additionally, other keys and keyways carried
respectively by the unit and by the syringe limit the angular
position in which the syringe may be inserted into the jacket to a
unique predetermined angular orientation. Preferably, three
keyways, such as slots or notches, unequally spaced around the
back, rearward or proximate edge of the syringe body, engage
similarly spaced keys or tabs on the unit at the rear end of the
pressure jacket to permit insertion of the syringe into the jacket
in one and only one orientation.
[0019] Further in accordance with principles of the present
invention, in its preferred embodiment, a coupling on the syringe
plunger is centrally located and symmetrical about the axis of the
plunger. A pair of jaws on the plunger drive is moveable either by
transverse straight or arcuate translatory motion or by forward
longitudinal motion to form a connection between the coupling and
the drive. Once coupled to the drive, the coupling remains engaged
to the drive during longitudinal motion of the drive to cause the
plunger to move forward or backward with the drive. Disengagement
occurs thereafter only upon transverse translational motion of the
plunger with respect to the drive. In certain embodiments, this
translatory transverse motion occurs by translatory movement of the
jacket, and the injector unit door that carries the jacket, with
respect to the plunger drive and the unit housing. In other
embodiments, an asymmetrical coupling is provided that engages and
disengages the plunger drive upon rotational movement of the
syringe with respect to the drive.
[0020] Preferably, the motion for locking the syringe to, and
unlocking the syringe from, the jacket is achieved by rotation of
the syringe in the jacket, and preferably, this motion is linked
to, and occurs simultaneous with, the motion that engages and
disengages the plunger coupling and drive, whether that coupling is
by translation or rotation. In addition, the syringe and plunger
drive are so dimensioned and positioned to prevent contact between
the drive and the sterile interior wall of the syringe, regardless
of the position of the drive, as the syringe is being loaded.
[0021] Preferably, the syringe is formed of a cylindrical body,
with the front end in the shape of a truncated cone that terminates
in a forwardly extending neck with an orifice at its remote end
that is connectable with an injection tube. The front end of the
syringe is shaped so as to direct fluid leaking from the nozzle
outwardly around the front end of the jacket. This prevents
leakage, which often results upon disconnection of the injection
tubing, from entering the space between the pressure jacket and the
syringe body.
[0022] Replacement of the syringe begins, in the preferred
embodiments of the invention, with the unlocking the syringe at its
front end from the front end of the pressure jacket, preferably by
rotating the syringe with respect to the jacket, and by disengaging
the plunger drive from the syringe plunger, alternatively by
transverse translational or rotational motion, preferably
simultaneous with and linked to the motion that disengages the
syringe from the jacket. The unlocking of the syringe from the
jacket occurs, for example, by loosening mating threads at the
front of the syringe and jacket. The twisting of the syringe in the
jacket is linked to motion that either translates transversely or
rotates a coupling on the syringe plunger out of engagement with
the plunger drive.
[0023] Then the syringe is removed from the jacket through the open
front end of the jacket. This removal may take place without
retraction of the plunger drive, should the drive be advanced in
the pressure jacket at the time of disengagement from the plunger
coupling. The used syringe may also be removed without
disconnection of the disposable injection tubing from the nozzle of
the syringe.
[0024] When the used syringe is removed, a replacement syringe is
inserted into the jacket through its open forward end and the front
end of the new syringe is locked to the front end of the jacket,
preferably by relative rotation of the syringe in the jacket to
cause, for example, engagement between mating threads on the front
end of the syringe and the front end of the jacket. The plunger
drive, in one embodiment, is translated to bring the plunger
coupling engaging jaws into alignment with the plunger coupling,
preferably simultaneously with the locking of the syringe to the
jacket. The jaws thereby either engage the coupling upon the
translatory motion, or thereafter engage the coupling by
longitudinal advancement of the drive against the coupling. In one
embodiment, the jaws are positioned off center of the drive so that
the drive, whether in the engaging or the disengaging positions,
does not contact a syringe as the syringe is guided by the jacket
during loading.
[0025] In an alternative embodiment, engagement of the plunger
drive with the coupling occurs by relative rotation of the drive
and the coupling, preferably by rotating the coupling relative to a
stationary plunger drive, rather than by translational motion
between the drive and the coupling. Only if the rest position of
the plunger of the replacement syringe is behind the final position
of the plunger drive at the time it was disconnected from the
coupling of the plunger of the syringe being replaced need the
plunger drive be retracted.
[0026] The engagement and disengagement motions between the plunger
drive and plunger drive coupling, and between the syringe and the
pressure jacket, are provided with manually operable mechanism
that, in the preferred and illustrated embodiments, rotates the
syringe in the jacket and further either rotates or translates the
coupling with respect to the plunger drive, with a simple one hand
operated mechanism. The mechanism provides a convenient lever,
operable through a short arc, to rotate the syringe in the jacket
and to then, preferably, translate the pressure jacket that carries
the syringe and is carried by the injector unit door, or to
otherwise move the syringe with respect to the drive, to bring the
plunger coupling of the syringe into or out of alignment with the
plunger drive.
[0027] The present invention provides a disposable syringe that may
be replaced in an angiographic or CT injector with great efficiency
and speed. Further, replacement may occur without retraction of the
plunger drive of the injector unit. Simple and rapid one hand
operation of the engaging and disengaging structure is
provided.
[0028] These and other objectives of the present invention will be
more readily apparent from the following detailed description of
the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a perspective view of an angiographic CT injector
embodying principles of the present invention.
[0030] FIG. 1A is a perspective view of an another form of
angiographic injector embodying principles of the present
invention.
[0031] FIG. 2 is an exploded perspective view of a portion of one
preferred embodiment of the injector of FIG. 1.
[0032] FIG. 3 is a perspective view of the portion of the injector
of FIG. 2.
[0033] FIG. 4 is a cross-sectional view along lines 4-4 of FIG. 3
illustrating a replaceable syringe unlocked from the housing for
insertion into or removal therefrom.
[0034] FIG. 5 is a cross-sectional view similar to FIG. 4 but
illustrating the syringe locked to the structure carried by the
housing.
[0035] FIG. 6 is a cross-sectional view along the line 6-6 of FIG.
5.
[0036] FIG. 7 is an elevational diagrammatic illustration of the
injector of FIG. 1 with the pressure jacket and syringe removed,
and showing the syringe locking structure in the locked position
such as in FIGS. 5 and 6.
[0037] FIG. 8 is an elevational diagrammatic view similar to FIG. 7
illustrating the syringe locking structure in the unlocked position
such as in FIGS. 2-4.
[0038] FIG. 9 is an elevational diagrammatic view similar to FIG. 7
illustrating the locking mechanism in the housing door release
position.
[0039] FIG. 10 is a cross-sectional view through the housing of the
injector taken along lines 10-10 of FIG. 1 with the plunger drive
disengaged from the syringe plunger coupling.
[0040] FIG. 11 is a view of a portion of FIG. 10 illustrating the
plunger drive longitudinally moving into engagement with the
plunger coupling.
[0041] FIG. 12 is a view of a portion of FIG. 10 illustrating the
plunger drive in engagement with the plunger coupling.
[0042] FIG. 13 is a front view of a portion of another embodiment
of the injector of FIG. 1.
[0043] FIG. 14 is a view of an alternative embodiment of a portion
of a syringe according to principles of the present invention.
[0044] FIG. 15 is a cross-sectional view similar to FIG. 5 of an
alternative embodiment of the invention, illustrating alternative
engaging structure between the front ends of the syringe and
jacket.
[0045] FIG. 16 is a cross-sectional view similar to FIG. 5 of a
further alternative embodiment of the invention, also illustrating
alternative engaging structure between the front ends of the
syringe and jacket.
[0046] FIG. 17 is a front end view of still a further alternative
embodiment of the invention, also illustrating alternative engaging
structure between the front ends of the syringe and jacket.
DETAILED DESCRIPTION OF THE DRAWINGS
[0047] Referring to FIG. 1, an angiographic injector 10 according
to another preferred embodiment of the present invention is
illustrated, configured for CT applications. The injector 10
includes a ceiling mounted support 11, adjacent a CT X-ray unit, to
the lower surface of which is rigidly supported a vertically
descending support column 12.
[0048] Remote from the support 11 is an injector control module
console 13 behind a wall which isolates the operator area from the
X-ray equipment. The console 13 is located adjacent a control 14 of
the X-ray equipment. Electrical power and control cables (not
shown) communicate power and control signals through the support 11
and the column 12 and to a power lead 15. The console 13 connects
with an injector control module 16, which includes a programmable
microprocessor (not shown) to which commands and programming codes
are input through a keyboard 17 on the console 13. The console 13
is also provided with an operator display 18 to aid in interfacing
the input commands and injector status with the operator.
[0049] Attached to the column 12 is an articulating adjustable arm
19. To the remote end of the arm 19 is adjustably supported
injection module unit 20. The arm 19 is capable of setting the unit
20 at varying positions adjacent a patient bed of the CT unit.
[0050] Referring to FIG. 1A, an angiographic injector 10a according
to another preferred embodiment of the present invention is
illustrated. The injector 10a includes a wheeled base 11a to the
top of which is rigidly supported a vertically adjustable
upstanding support column 12a. To the top of the column 12a is
supported a control module platform 13a. Electrical power is
communicated from a power cord (not shown) through the base 11 and
the upstanding support 12a and through a power lead 15a to a
control module 16a rigidly supported to the platform 13a. The
control module 16a includes a programmable microprocessor (not
shown) to which commands and programming codes are input through a
keyboard 17a on the module 16a. The module 16a is also provided
with an operator display 18a to aid in interfacing the input
commands and injector status with the operator. Attached to the
platform 13a is an articulating adjustable arm 19a. To the remote
end of the arm 19a is adjustably supported the injection module
unit 20.
[0051] The injection module unit 20 of the embodiments of FIGS. 1
and 1A includes a housing 21 which contains the operating drive
structure of the injector 10 or 10a. The housing 21 has a support
bracket 23 fixed thereto and adjustably pivotally supported to the
remote end 24 of the articulating arm 19 or 19a. The housing 21 has
pivotally attached to the front thereof a door 25 at the front
thereof which is pivotally connected to the housing 21 at a
longitudinally extending pivot or hinge pin 26 (FIG. 2) rigidly
supported on the housing 21 and extending forwardly from the front
of the housing 21.
[0052] On the top of the housing 21 is an injector position and
local control panel 27 having a position indicator scale 28
thereon, which displays the position of the injector drive to the
operator. The panel 27 also includes a pair of forward and reverse
drive direction control buttons 29, which are selectively
actuatable to activate a drive within the housing 21 in either the
forward or reverse directions.
[0053] Extending forwardly from the front of the door 25 is an
injector syringe and pressure jacket assembly 30, the structure of
which can be better understood with reference to FIGS. 2-5 below.
The syringe and jacket assembly 30 includes a hard plastic pressure
jacket 31, which may be of opaque or transparent material, a
removable and replaceable disposable syringe 32, which may be of
opaque, transparent or semi-transparent material, and related
structure hereinafter described.
[0054] The syringe 32 is disposable, and includes walls which will
withstand only moderate or low pressure. The walls are usually
outwardly deformable under operating pressures, particularly
pressures of 300 psi or more. Such higher pressures are necessary
to overcome pressure drops through the injection tubing at higher
flow rates, which are often desirable. The jacket 31 is made of a
stronger transparent material that will withstand the operating
pressures. When the syringe 32 is contained in the jacket 31, it is
surrounded by the jacket 31 and supported by the jacket 31 against
expansion caused by the fluid pressure within as the syringe 32
expands against the jacket wall.
[0055] The pressure jacket 31 has a generally cylindrical inner
bore 33 extending therethrough from a proximate end 34 adjacent the
door 25 to a remote end 35 of the pressure jacket 31 toward the
front of the unit 20. The bore 33 is dimensioned so as to receive
through the remote end 35 the disposable syringe 32 and to support
the syringe against expansion from fluid pressure within such fluid
pressure may range to more than a thousand psi. The pressure jacket
31 has an annular flange 37 extending outwardly around the
proximate end 34. The flange 37 is integrally formed with the
jacket cylinder and is shaped to conform to an annular recess 38
surrounding a circular hole 39 in the door 25 to which the jacket
31 may be assembled by insertion from the rear. The hole or opening
39 in the door 25 and the cylindrical bore 33 of the jacket 31 are
concentric with a longitudinal axis 40 on which also lies an axis
41 of the syringe 32 when the syringe 32 is positioned in the bore
33 of the jacket 31. The jacket 31 is firmly and rigidly attached
to the door 25 with a pair of screws 43, only one of which is
shown, which are threaded into a pair of holes 44 in the back of
the door 25 (FIG. 2). An O-ring seal 46 surrounds the flange 37 of
the jacket 31 in the recess 38 of the door 25.
[0056] The syringe 32 includes a syringe case 50 formed of a single
piece of molded plastic material, a pressure cap 51, a tubing
collar 52 (FIG. 3) and a plunger 54 (FIGS. 3-5). The syringe case
50 includes a cylindrical syringe body 55 having an open proximate
end 56 and a remote end 58 to which is integrally formed a conical
front wall 57. The front wall 57 is truncated at its forward end,
to which is integrally formed an elongated neck 59 extending from
the wall 57 at the center thereof. The neck 59 of the syringe case
50 has an orifice 60 (FIG. 3) in its remote end which communicates
with an internal syringe cavity 61 formed within the neck 59, the
conical front wall 57 and the cylindrical body 55 of the case 50 of
the syringe 32. The rear end of the cavity 61 is further defined by
a forward facing conical surface 64 of the plunger 54. The conical
surface 64 is of a slope which conforms to the slope of the
interior of the conical front wall 57. The plunger 54 is slidable
within the body 55 of the syringe case 50 such that the cavity 61
is of variable volume.
[0057] Near the front end of the neck 59 of the syringe case 50,
just behind the orifice 60, is an external thread 66 configured to
mate with threads 67 on the interior of collar 52 (FIG. 3). The
thread 66 in the neck 59 has an stop 69 at near forward end thereof
to engage an abrupt step 70 on the thread 67 of the collar 52 so
that, when the syringe 32 is properly oriented in the jacket 31,
the collar 52, when loosened to its maximum extent, will assume a
predetermined orientation so as to present, in an upwardly facing
orientation, a tube end receiving slot 62 formed in the remote end
of the collar 52. This slot 62 is of T-shaped cross-section so as
to receive the enlarged flange end 63 of a tube 65 through which
fluid from the syringe cavity 61 is injected into a patient.
[0058] The cap 51 is generally conical in shape and has an inner
rearward surface 75, which conforms to the front surface of the
conical wall 57 of the case 50 of the syringe 32. In certain
embodiments, the rearward conical surface 75 of the cap 51 may be
bonded to the front surface of the conical wall 57 of the case 50
of the syringe 32, or it may be formed integrally therewith, molded
from the same plastic material as the case 50 of the syringe 32. In
the preferred and illustrated embodiment, the cap 51 is separate
from the syringe body portion 55 and has a pair of holes or detents
76 into which fit a pair of projections 77 extending forwardly from
and formed integrally on the outer surface of the conical wall 57
of the case 50 of the syringe 32. The cooperation of the pins or
projections 77 with the holes or detents 76 prevent the cap from
rotating with respect to the syringe case 50 when the cap 51 is
mounted on the syringe 32.
[0059] To hold the cap 51 against the conical wall 57 of the case
50 of the syringe 32, six resilient tabs 78 are formed about a
central inner hole 79 of the cap 51. The tabs 78 are separated by
six equally spaced radial slots 80 (FIG. 3). The hole 79 in the cap
51 is equal to or only slightly greater in size than the circular
forward end of the conical wall 57 of the case 50 of the syringe
32. The neck 59 of the syringe 32 has an enlarged straight section
81 slightly greater in diameter than the hole 79 in the cap 51 and
also greater in diameter than the forward end of the conical wall
57 of the case 50, thereby forming a groove 82 at the juncture of
the straight neck portion 81 with the conical wall 57 so that the
tips of the tabs 78, which are sufficiently resilient to slide over
the enlarged neck portion 81 as the cap 51 is inserted on the case
50 of the syringe 32 with the hole 79 surrounding the neck 59 to
snap fit into the groove 82.
[0060] The syringe 32 includes structure that is configured to lock
the syringe 32 to the front end of the jacket 31 by cooperating
with mating structure on the jacket 31. The jacket 31 has, spaced
around the circumference thereof near the remote or front end 35 of
the jacket 31, four equally spaced outwardly projecting thread
sections 85. These thread sections 85 are slightly less than
45.degree. in extension around the circumference of the jacket 31
and are spaced apart with gaps of slightly greater than 45.degree..
The cap 51 has a cylindrical rim 87 in which are formed four
similarly sized and spaced mating thread sections 86. The thread
sections 86 project inwardly toward the jacket 31 when the syringe
32 is positioned in the jacket 31. As such, when the syringe 32,
with the cap 51 assembled to it is inserted into the jacket 31, the
threads 86 of the cap 51 pass through the spaces between the
threads 85 on the jacket 31 to a point behind the threads 85. When
so inserted, the syringe assembly 32 with the cap 51 may be twisted
clockwise 45.degree. to tighten and thereby secure the cap 51 to
the jacket 31 by engagement between the threads 85 and 86 as shown
in FIG. 5, to thereby lock the syringe in the bore 33.
[0061] The piston 54 of the syringe 32 is molded of an elastomeric
material. Preferably, the piston 54 includes two portions molded of
different materials and bonded together. These portions include a
forward more flexible portion 90 in which is formed the forward
conical surface 34. This forward portion 90 has a pair of outwardly
extending rings 91 formed in the periphery thereof to make sealing
engagement with the inside of the wall of the cylindrical body 55
of the syringe case 50. The rearward portion of the piston 54 is a
flat circular surface to which is bonded the flat circular forward
surface of a more rigid rear portion 93 of the piston 54. The rear
rigid portion 93 of the piston 54 is molded of a harder stronger
plastic material and has a rearward facing circular surface 95
having a rearward extending coupling 96 integrally formed thereon
at its center. The coupling 96 includes a rearwardly extending
cylindrical shaft 97 on the axis 41 of the syringe 32 and a larger
symmetrical cylindrical button 98 integrally formed at the rear end
of the cylindrical shaft 97.
[0062] Referring to FIG. 10, a piston drive assembly 100 is
illustrated contained within the housing 21. The drive assembly 100
includes an electric motor 101 mounted within the fixed housing 21
and having a rotary output shaft 102 with a drive gear 103 fixed to
the remote end thereof. The drive gear 103 is positioned for
driving engagement with a driven gear 104 fixed near the rear end
of a drive screw or shaft 105 supported at its rear end in a
bearing 106 fixed in the housing 21. The screw or shaft 105 has a
continuous external helical thread 107 thereon which mates with
interior threads of a carriage 108. The carriage 108 is slidably
supported in a bushing 109 fixed in the housing 21. The shaft 105
rotates within the housing 21 about a longitudinal axis 112.
[0063] At the forward end of the carriage 108 is supported a pair
of hooked jaws 114 which are pivotally mounted at their rearward
ends by a pair of pivot pins 115 to the carriage 108. The jaws 114
are biased toward the axis 112 by a pair of balls 116a and 116b of
resilient material positioned between the outside of the jaws 114
and an inner cylindrical wall 117 of a recess 118 formed in the
forward end of the carriage 108. The balls 116a, 116b are partially
captured in depressions in the outer surfaces of the jaws 114. The
balls 116a, 116b bias the jaws toward their innermost position
toward the axis 112. The innermost position of the jaws is
determined by a spacing block 119 on the axis 112 of the carriage
108 at the center of the cavity 118.
[0064] When a syringe 32 is locked in the jacket 31 with its axis
41 and the axis 40 of the jacket 31 may be in alignment with the
axis 112 of the shaft 105, the plunger 54 may be located in the
cylindrical body 55 of the syringe case 50 in a position forward of
the remote end 56. Preferably, however, the jaws 114 are displaced
to the side of axis 112 of the shaft 105 so that as the jaws 114
and coupling tip 98 are in their disengagement position, maximum
clearance is provided so that the syringe 32 may be inserted into
the jacket 31 without the sterile internal walls of the syringe 31
touching the components of the drive, as illustrated in the
figures.
[0065] In the engaging position, the jaws 114 are nonetheless in
alignment with the coupling 98 on the axes 40 and 41 of the jacket
32 and syringe 32. In such a situation, the jaws 114 may be in a
retracted position at the center of the opening 39 of the door 25
adjacent to the proximate end 34 of the jacket 31, and out of
engagement with the coupling 96 on the plunger 54. From this
position, operation of the motor 101 rotates the shaft 105 and
drives the carriage 108 forwardly to move the jaws 114 toward and
into engagement with the coupling 96 on the plunger 54. This
engagement takes place as shown in FIG. 11 where a pair of tapered
cam surfaces 120 at the forward interface of the tips of the jaws
114 engage the enlarged portion or button 98 of the coupling 96 to
expand the jaws, as shown in FIG. 11, to snap around the button 98
of the coupling 96 to form a driving engagement between the drive
assembly 100 and the coupling 96 of the plunger 54 as shown in FIG.
12. Once so engaged, any forward or reverse movement of the
carriage 108 under the power of the motor 101 will cause the
plunger 54 to be driven either forwardly or backwardly in the
syringe body 55.
[0066] Disengagement of the jaws 114 from the coupling 96 can
thereafter be achieved by translational movement between the
coupling 96 and the jaws 114 between a disengaged position as shown
in FIG. 4 and an engaged position as shown in FIG. 5. When the
plunger coupling 96 and the jaws 114 are disengaged, the syringe 32
can be replaced without the need to retract the carriage 108 of the
drive 100. This allows for rapid replacement of the syringe 32.
Preferably, the jaws 114 are either fully retracted toward the
housing 21 where engagement by translation of the coupling 96 will
occur, or the jaws 114 are sufficiently within the jacket prior to
replacement of the syringe so that the coupling 96 of the
replacement syringe 32 will not contact the jaws 114 except as the
drive 100 is advanced.
[0067] If sterility is not a problem, the most time saving approach
would be to insert the syringe 32 into the jacket 31 with its
plunger all the way forward and the drive fully advanced so that,
when the syringe is translated toward the jaws 114, engagement will
immediately occur and the plunger can be immediately retracted to
fill the syringe.
[0068] When a syringe 32 is inserted into the jacket 31 when the
plunger 54 is at its rearmost position toward the proximate end 56
of the syringe body 55, the coupling 96 is in a position adjacent
the proximate end 56 of the syringe body 55 and projecting
rearwardly therebeyond. When in such a position, engagement between
the jaws 114 and the coupling 96 is brought about by translational
movement between the position shown in FIG. 4 and that shown in
FIG. 5. In the unlocked or disengaged position shown in FIG. 4, the
axes 40 and 41 of the jacket 31 and the syringe 32, respectively,
as well as the center of the opening 39 of the door 25, lie spaced
from and parallel to the axis 112 of the shaft 105 as shown in FIG.
4. In the locked or engaged position, the axis 112 of the shaft 105
is slightly eccentric relative to the axes 40 and 41 of the jacket
31 and syringe 32, respectively, as shown in FIG. 5. This
translational movement, the engagement and disengagement between
the coupling 96 and the jaws 114 and the 45.degree. rotational
movement which secures the cap 51 to the pressure jacket 31 by
engagement of the threads 85 and 86 are brought about by operation
of a translating and locking mechanism 125, which is best
understood by reference to FIGS. 2-9.
[0069] The translating and locking mechanism 125 includes a cam and
locking ring 127 which is rotatably retained in a circular recess
126 in the back of the door 25. The ring 127 has a generally
semi-circular groove 130 in the back surface thereof for receiving
a spring wire retaining clip 131 having a pair of looped ends 133
which extend through a pair of slots 134 in the rim of the ring 127
and into a selected one of three pair of diametrically opposed
notches 135, 136 and 137 in the inner wall of the rim of the recess
126 in the door 25. The three pair of notches 135, 136 and 137
represent three positions of the translating and locking mechanism
125 which are the locked, unlocked and release positions,
respectively. The locked position of the mechanism 125 in which the
loops 133 of the ring 131 are in the notches 135, is that
illustrated in FIGS. 5-7 and 10. The unlocked position, in which
the loops 133 of the ring 131 are in the notches 136, is that
illustrated in FIGS. 2-4 and 8. The release position, in which the
loops 135 of the clip 133 are in notches 137, is that illustrated
in FIG. 9. The ring 127 is moved among these three positions by a
manually accessible handle 138 in the form of a cylindrical knob
139 rotatably attached to a lever arm 140 formed integrally and
extending radially from the ring 127 through a slot 141 in the door
25 (FIG. 1). The ring 127 is retained in the recess 126 by a pair
of screws 143 which thread into countersunk holes 144 at the
periphery of the recess 126 in the back of the door 25. These
screws 143 have enlarged heads 146, which, when seated in the holes
144, overlie the edge of the ring 127, thereby securing it for
rotatable movement within the recess 126.
[0070] As shown in FIGS. 2 and 6, the ring 127 has an inner
periphery 149 which is larger than the circumference of the body 55
of the syringe case 50. Accordingly, when the syringe 32 is
inserted in the jacket 31, the proximate end 56 of the syringe case
50 extends through and is surrounded by the inner periphery 149 of
the ring 127. Asymmetric keyway structure, preferably in the form
of three slots or notches 151, 152 and 153 (FIG. 6) are provided in
the edge of the proximate end 56 of the body 55 of the syringe case
50. The spacings between adjacent pairs of the notches 151-153
differ from each other. Formed integrally of the ring 127 and
projecting inwardly from the inner periphery 149 thereof are three
tabs or keys 155, 156 and 157. These tabs 155-157 are spaced so as
to fit into the respective notches 151-153 in the proximate end 56
of the body 55 of the syringe case 50 so as to rotate the syringe
32 as the mechanism 125 is rotated through actuation of the handle
138. Because the notches 151-153 and the tabs 155-157 are unequally
spaced, they can only engage each other when the syringe 32 is
inserted into the jacket 31 in one and only one orientation. That
orientation is one which will cause the slot 62 of the collar 52
(FIG. 3) to align 45.degree. counterclockwise of the vertical when
the mechanism 125 is in its unlocked position, which is a position
in which it will be when the syringe is first inserted into the
jacket 31, and to be in an upwardly facing orientation, when fully
loosened, when the mechanism 125 is moved to its locked position.
Accordingly, the notches 135 and 136 in the recess 126, which
receive the loops 133 of the spring clip 131 when respectively in
the locked and unlocked positions, are 45.degree. apart.
[0071] The rotation of the mechanism 125 from the unlocked position
to the locked position rotates the syringe 32 in the jacket 31 and
rotates the cap such that its threads move from an unlocked
position as shown in FIG. 4 to the locked position of FIG. 5, to
secure the cap to the jacket 31 by the engagement and tightening of
the threads 85 and 86.
[0072] The translational movement of the axes 40 and 41 with
respect to the axis 112 is achieved by a fixed cylindrical cam
follower or pin 150 which projects outwardly from the fixed housing
portion 22 behind the ring 127 and into a cam slot 154 formed
therein. The slot 154 is shaped so that the axes 40 and 41 which
remain fixed with respect to the ring 127, along with the door 25,
the jacket 31, the syringe 32 and all of the structure mutually
carried thereby, are moved in relation to the axis 112 of the shaft
105 and the other structure mutually carried by the housing 22, as
the mechanism 125 is rotated. These axes move toward and away from
each other in accordance with the shape of the slot 154 determined
by the radial distance from the point along the slot 154 where it
engages the pin 150 to the axes 40 and 41.
[0073] The cam slot 154 in the ring 127 is shaped such that, when
the mechanism 125 is in the locked position as shown, for example,
in FIGS. 6 and 7, the distance between the pin 150 and the axes 40
and 41 is at a minimum and the axis 112 coincides with the axes 40
and 41. This is illustrated in FIGS. 5 and 7 wherein the coupling
96 is shown positioned between the jaws 114 and in mutual
engagement therewith. When the mechanism 125 is in the unlocked
position, with the loops 133 of clip 131 in the notches 135 (FIG.
6) of the recess 126, the pin 150 lies in the slot 154 in the
position shown in FIG. 8, which is farther displaced from the axes
40 and 41 than in the position of FIGS. 6 and 7, so that the
coupling 96 is translated to a position outside of the center line
of the jaws 114, as shown in FIG. 8 and further illustrated in FIG.
4.
[0074] In the release position, as shown in FIG. 9, the pin 150 is
positioned at the open end 160 of the cam surface of the slot 154
so that the door 25 can be rotated upwardly about the hinge pin 26,
as shown in FIG. 9, to open the space behind the door 25 for access
thereto. This position may be used for cleaning the area behind the
door 25 which is sometimes necessary because of possible leakage of
fluid from the cavity 61 into the space behind the plunger 54. This
can possibly occur because the fluid within the cavity 61, when
being injected by forward advancement of the plunger 54, may be of
relatively high pressure in the range, usually over 200 psi. For
applications such as the injection of contrasting fluid for CT
scanning, pressure may typically be in the range of from 25 to 300
psi., while in some angiographic injection applications the
pressure may range to 1200 psi or higher.
[0075] In addition, leakage rearwardly along the exterior of the
neck 59 of the syringe 32 can cause fluid to flow between the body
portion 55 of the syringe 32 and the jacket 31. For this reason,
the cap 51 is caused to fit snugly against the forward surface of
the conical portion 57 of the syringe 32 at least sufficiently to
restrict the flow of this leaking fluid onto the neck 59. This is
assisted by the configuration of the cap 51 at the rim 87 thereof
so as to divert away from the space between the syringe 32 and
jacket 31 fluid which might leak from the nozzle.
[0076] The front of the housing 21 has formed thereon a door stop
185 having a slot 186 formed therein for receiving a lug 187 of the
door 25, to restrain the door 25 against forward force exerted by
the drive 100. Behind the front of the housing 21 adjacent the stop
185 is a magnetic sensor 188, which is responsive to the presence
of a magnet 189 in the lever arm 139 of the handle 138. The sensor
188 generates a signal to the control module 16 to activate the
drive 100 only when the mechanism 125 is in its locked
position.
[0077] Referring to FIG. 13, there is illustrated a locking
mechanism 225 that is an alternative to the locking mechanism 125
described above. In the locking mechanism 225, a stationary geared
rack 250 is provided fixed to the housing 21. A mating gear segment
254 is formed on the outer rim of the alternative locking ring 227
of this embodiment. The gear segment 254 and rack 250 replace and
function in the same way as the slot 154 and pin 150 of the
embodiment described above. As the mechanism 225 is rotated by the
handle 138, the door 25 that carries the jacket 31 and the syringe
32 is translated to bring the coupling 96 into or out of engagement
with the jaws 114 of the drive 100. Simultaneous with this
translatory motion, the syringe 32 is rotated in the jacket 31 to
lock or unlock the syringe 32 to the jacket 31 by engagement or
disengagement of the threads 86 on the syringe 32 with the threads
85 on the jacket 32.
[0078] FIG. 14 illustrates an alternative to the embodiment of the
coupling 96 described above. In the embodiment of FIG. 14, there is
provided a coupling 296 that is T-shaped, having a rectangular
endpiece 298 at the rearward end of a cylindrical or square shaft
297 on the rearwardly facing circular surface 95 of the plunger 54.
Such a coupling 296 engages the jaws 114 by rotation of the locking
mechanism 125 or 225, preferably through an angle of 90.degree..
When the orientation of the endpiece 298 is parallel to the plane
of the jaws 114, the drive 100 is locked to the plunger 54 so that
axial movement of the drive 100 moves the plunger axially, in the
forward direction to expel fluid form the syringe cavity 61, or in
a rearward direction to fill the cavity 61 with fluid. When the
endpiece 298 is perpendicular to the plane of the jaws 114, the
coupling 296 will move into or out of engagement with the jaws 114
upon relative axial movement between the plunger 54 and the drive
100. Thus, with this embodiment, rotational motion, rather than
translational motion, causes engagement and disengagement of the
coupling 296 by the jaws 114. With this embodiment, orientation of
the syringe 32, when loaded into the jacket 31, is preferably
maintained through the cooperation of the notches 151-153 and the
tabs 154-156 (FIG. 4), so that the coupling 296 will enter the jaws
114, when the syringe 32 is inserted into the jacket 31, with the
endpiece 298 perpendicular to the pair of jaws 114.
[0079] The locking structure between the syringe 32 and the
pressure jacket 31 should provide for retention of the syringe 32
in the jacket 31 against the force of the fluid pressure in the
cavity 61 or axial force otherwise exerted on the plunger 54 by the
drive 100. This locking of the syringe 32 to the jacket 31 is
preferably achieved, as shown in FIG. 5, by structure at or near
the forward wall 57 of the syringe case 50. In accordance with the
embodiment of FIG. 15, such structure may include external threads
200 on the forward end of the syringe body 257, which mate with
internal threads 201 at the remote end of the jacket 31. With such
an embodiment, the syringe 32 is preferably provided with an
annular flange 203 around the body 257 at the juncture of the body
257 with the syringe front wall 258. The flange 203 inhibits the
flow of leaked fluid into the space between the syringe body 257
and the jacket 31. With such an embodiment, the wall 258 is either
thickened, provided with reinforcing such as the ribs 208, or
provided with other structure to resist deformation of the wall 258
under the pressure of the fluid within the cavity 61.
[0080] Alternatively, a reusable split clip 210 may be employed to
secure a continuous flange 203 of such a syringe to a continuous
flange 212 at the end of the pressure jacket in the embodiment of
FIG. 16. As a further alternative as shown in FIG. 17, a ring clip
210a having an outer rim 215 and rotatably mounted to the syringe
31, encircles and engages outwardly projecting threads of a disk
flange 213 formed at the front end of the jacket 31, as the syringe
32 is twisted onto the jacket 31, to engage the jacket in a manner
similar to the threads 85 and 86 in the embodiment of FIGS. 2-12
above.
[0081] The invention has been described in the context of its
preferred embodiments. It will be appreciated by those skilled in
the art that variations and alternatives to the embodiments
described may be employed without departing from the principles of
the present invention. Accordingly, this patent is not intended to
be limited except by the scope of the following claims:
* * * * *