Title:
POWER OPERATED SYRINGE HOLDING DEVICE FOR FILTERING A LIQUID
United States Patent 3807464
Abstract:
A portable, power operated device for forcing a liquid from a syringe through a presterilized microfilter holder operatively associated therewith into a sterile container. The use of the device not only eliminates the tiring and time-consuming operation of manually maintaining pressure on the plunger of the syringe during the filtering operation, but the hazard of the operator being seriously cut or otherwise injured should the glass syringe shatter.
Application Number:
05/303678
Publication Date:
04/30/1974
Other Classes:
128/DIG.1, 141/258, 141/286, 141/375, 222/334, 604/143
International Classes:
A61M5/178; A61J1/00; A61J1/20; A61M5/178; A61J1/00; A61J1/14; (IPC1-7): B65B3/12
Field of Search:
141/20,27,67,97,258,286,375,376 128
Primary Examiner:
Bell Jr., Houston S.
Claims:
I claim
1. In combination with a syringe that includes a cylindrical shell that has a first externally beaded end and a second apertured end, a plunger slidably and sealingly mounted in said shell and projecting from said first end thereof, a quantity of liquid to be filtered disposed inside said shell between said plunger and said second end, a filter assembly having first and second apertured ends, said first end of said assembly removably and sealingly engaging said second end of said syringe, and a sterile container for receiving filtered liquid from said second end of said filter assembly, a device operated by pressurized air from a source therof for moving said plunger towards said second end to force said liquid in said shell through said filter assembly into said sterile container in a filtered condition, said device including:
2. The combination as defined in claim 1 in which said first means is a base secured to said second end of said upright.
3. The combination as defined in claim 1 in which said spring means is a compressed helical spring disposed in said bore and counterbore in said upright, said spring having a first upper end and a lower second end, with said first end in pressure contact with said piston and said second end bearing against said second body shoulder.
4. The combination as defined in claim 3 which in addition includes:
5. The combination as defined in claim 4 in which said alignment rod is of such length as to act as a stop to limit downward movement of said arm when said alignment rod contacts said second body shoulder.
6. The combination as defined in claim 1 which in addition includes:
7. The combination as defined in claim 1 which in addition includes:
8. The combination as defined in claim 1 in which said first means includes:
9. The combination as defined in claim 8 in which said first valve member is of less transverse cross section than that of said first bore in said second head portion in which it is disposed and cooperates therewith to define a first annulus-shaped space that is at all times in communication with said air passage, said second valve means being movably supported on said first valve means, and said second valve means establishing communication between said first annulus-shaped space and the ambient atmosphere when said second valve means is in said second position.
10. The combination as defined in claim 9 in which said first handle, boss and valve member have a second bore extending longitudinally therein that develops into a second valve seat from which an air passage in said first valve member extends to said first annulus-shaped space, said second bore having second threads defined in an outer portion thereof and said second valve means includes:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
Power operated syringe holding device for filtering a liquid.
2. Description of the Prior Art
The sterilization or clarification of small quantities of liquids is conveniently carried out by forcing the latter through a syringe type filter assembly. The syringe containing the liquid to be filtered is connected to a presterilized microfilter holder containing a suitable membrane, with the plunger of the syringe having a steady, manually applied force exerted thereon to force the liquid through the membrane into a sterile container. Such a procedure is time-consuming and tiring for the operator, and has the further operation disadvantage that the operator may be cut or otherwise injured should a glass syringe shatter during the filtering operation.
The primary purpose in devising the present invention is to not only minimize the time required for such a filtering operation and the physical effort required on the part of the operator, but to safeguard the operator being cut or injured by the shattering of a glass syringe.
SUMMARY OF THE INVENTION
A portable device that includes a base that has a tubular upright secured thereto in which an upwardly biased spring-loaded piston is slidably and sealingly mounted. The upright terminates at the upper end thereof in a syringe and filter assembly-supporting head. A sterile bottle support is adjustably secured to the upright for vertical movement thereon.
The piston is secured to an upwardly extending rod that has a horizontal arm projecting therefrom that is capable of exerting a downwardly directed force on the plunger of a syringe supported by the device when air under pressure is discharged into the interior of the upright above the piston.
Flow of air under pressure to the interior of the upright is controlled by opening a first valve, with the first valve being closed when the arm has moved the plunger of the syringe downwardly to a desired degree. A second valve that is preferably included as a part of the first valve may be opened when the first valve is in a closed position to permit air under pressure within the upright to escape therefrom at a desired rate. As air under pressure escapes from the interior of the upright, the spring-loaded piston moves upwardly to return the arm to its initial position to permit the syringe, filter and sterile bottle to be removed from the device.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the device removably supporting a syringe, filter and sterile bottle for receiving the filtered liquid;
FIG. 2 is a longitudinal cross-sectional view of the device taken on the line 2--2 of FIG. 1; and
FIG. 3 is a transverse cross-sectional view of the device taken on the line 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device A, as may best be seen in FIG. 1, includes a base B that has a rigid upright C secured thereto. Upright C on the upper end thereof develops into a transverse head D that includes first and second oppositely disposed portions 10 and 12. The first portion 10 has a stepped recess 14 therein that removably engages the circular lip 16 of a syringe E as well as the upper portion of a cylindrical shell 18 situated directly below the lip. The lower end of shell 18 is so formed as to removably engage a conventional filter assembly F, such as manufactured by the Millipore Company. The filter assembly F has a tube 20 depending therefrom through which filtered liquid flows by gravity to a sterile bottle G that is mounted on a horizontal support H. The support H is vertically adjustable on upright C as may be seen in FIG. 1.
A bore 22 extends downwardly in upright C from the upper end thereof. A counterbore 24 is defined in upright C below bore 22, and with a horizontal circular body shoulder 26 being defined at the junction of the bore and counterbore. An air vent passage 28 extends upwardly through base B and the lower part of upright C to communicate with counterbore 24.
The upper part of bore 22 has threads 28 formed therein that engage a first externally threaded upper portion 30 of a plug J. The plug J has a second smooth surfaced cylindrical portion 32 below the first portion 30. A bore 34 extends longitudinally through plug J. The exterior surface of portion 32 and the interior surface thereof that define bore 34 have first and second circumferential grooves 36 and 38 therein that support resilient sealing rings 36a and 38a respectively. Ring 36a effects a fluidtight seal with the surface of upright C that defines bore 22.
A piston K is slidably mounted in bore 22. Piston K has a rod 40 extending upwardly therefrom, which rod on the upper end supports a horizontal force-exerting arm L. Arm L is secured to the upper end of rod 40 by a bolt 42 or other conventional means. Piston K has at least one circumferential groove 42 therein that supports a resilient sealing ring 44 that is in slidably sealing contact with the surface that defines the bore 22.
The plug J, as best seen in FIG. 2, has a stop 46 projecting downwardly therefrom that contacts the uppermost horizontal surface 48 of piston K when the piston is in an up position. The lower surface of plug J, surface 48 of piston K and a portion of the wall-defining bore 22 cooperate to define an annulus-shaped space 50 that varies in volume as the piston K moves upwardly and downwardly in bore 22.
A longitudinal passage 52 is formed in second head portion 12, as shown in FIG. 3, that has a first end 52a thereof in communication with space 40, and a second end 52b thereof intersecting a first transverse bore 54 formed in the second head portion 12. First bore 54 inwardly from the position where it is intersected by passage 52 develops into a first frusto-conical valve seat 56 that is in communication with a coaxially aligned counterbore 58. Counterbore 58 is in communication with a tapped recess 60 formed in second head portion 12. Recess 60 is engaged by an externally threaded tubing fitting 62 of conventional design that is connected to a pliable conduit 64 that extends to a source of pressurized air (not shown).
Bore 54 has a threaded outer portion 54a, as best seen in FIG. 3. A first valve M is provided that includes a circular handle 66 that has an externally threaded boss 68 projecting from the center thereof, and the boss developing into a first elongate valve member 70 that has a free end 70that effects a liquidtight seal when in pressure contact with seat 56. First valve member 70 is of a substantially lesser transverse cross section than that of first bore 54. The exterior surface of first valve member 70 and the surface defining first bore 54 cooperate to define a first annulus-shaped space 72 therebetween that is at all times in communication with passage 52.
When handle 66 of first valve M is rotated in an appropriate direction, first valve member surface 70a is separated from seat 56 and moves from the first position shown in FIG. 3 to a second position where air under pressure may flow through passage 52 in space 50 to force piston K downwardly in bore 22, with concurrent downward movement of arm L. When a syringe E, filter assembly F and sterile container G are supported on the device A, this downward movement of arm L exerts a downward force on plunger 74 of the syringe. Plunger 74 as a result of this force is moved downwardly in cylindrical shell 18 for liquid therein to be forced through the filter assembly F into sterile container G. When first valve member 70 is in the first position shown in FIG. 3, communication between counterbore 58 and air passage 52 is blocked.
Downward movement of piston K in bore 22 is at all times resisted by a compressed helical spring 76 that has a first end thereof bottomed on a second body shoulder 78 formed at the junction of counterbore 24 and airvent passage 28 in upright C, as shown in FIG. 2.
The spring 70 extends upwardly into a cavity 80 formed in piston K and rod 40, as shown in FIG. 2. Cavity 80 develops on the upper end thereof into a tapped recess 82 that engages the upper threaded end 84 of an alignment rod 86 that extends downwardly and is encircled by the spring 76. The second end of spring 76 abuts against a third body shoulder 88 defined at the junction of cavity 80 and recess 82. The rod 86 serves to prevent buckling of spring 76 as the latter is further compressed by downward movement of piston K. The rod 86 is preferably of such length as to act as a stop to limit downward movement of arm L, when the lower end of the rod contacts second body shoulder 78, as shown in FIG. 2.
A second valve N is supported by first valve M as illustrated in FIG. 3. Second valve N includes a second circular handle 90 that has an externally threaded second boss 92 projecting from a central portion thereof that develops into a second elongate valve member 94 that terminates in a second frusto-conical valve surface 96.
First valve M has a centrally disposed longitudinal bore 98 therein that terminates on a first end in a frusto-conical valve seat 100 and at a second end develops into an internally threaded portion 102. First valve member 70 has a first L-shaped air passage 104 therein that is at all times in communication with first annulus space 72 and second valve seat 96. The exterior surface of second valve member 94 and the surface defining bore 98 cooperate to define a second annulus-shaped space 106 therebetween. Annulus-shaped space 106 is at all times in communication with a second L-shaped air passage 108 formed in second valve member N, as shown in FIG. 3.
When it is desired to move the plunger 74 downwardly by use of the device A and with the syringe E disposed as shown in FIG. 1, the first valve is rotated to move from the first position illustrated in FIG. 3 to a second position. First valve M, when in a second position, permits pressurized air to flow through passage 52 to space 50 and move piston K, rod 40 and arm L downwardly. Downward movement of piston K results in spring 76 being further compressed. Air in bore 22 and counterbore 24 escapes through airvent 28 as downward movement of piston K takes place. Upon upward movement of piston K, air flows from the ambient atmosphere into the counterbore 24 and bore 22 through passage 28 to prevent a negative pressure developing within the confines of the upright C.
After the arm L has been moved downwardly to a desired degree, as above described, the first valve M is rotated to return the same to the first position illustrated in FIG. 3. The piston K, rod 40 and arm L are returned as an integral unit to the first position shown in FIGS. 1 and 2 by expansion of spring 76 when the second valve N is rotated to a second position.
When the first valve is moved from the second to the first position as above described, pressurized air is present in space 50, passage 52, and second confined space 72. Moving the second valve N to a second position after the first valve M is disposed in a first position permits pressurized air to flow from first annulus-shaped space 72 through first L-shaped passage 104 to second annulus-shaped space 106, and from this space through second L-shaped passage 108 to the ambient atmosphere. The rate at which air is allowed to escape from space 50 by manipulation of second valve N determines the rate at which the compressed spring 76 will return the piston K, rod 40 and arm L to the first position shown in FIGS. 1 and 2.
The support H is preferably provided with a thumb screw 110 that may be moved into frictional contact with upright C to maintain the support at a desired elevation thereon.
A transparent safety shield 112 of generally U-shaped transverse cross section is secured to upright C by screws 113 and extends around syringe E when the latter is positioned as shown in FIG. 1 to protect the operator (not shown) from flying glass should the syringe shatter as pressure is applied to the interior thereof.
If desired, base B may have cavities 114 formed therein to removably hold components 116 of filter assembly F.
The use and operation of the invention has been explained previously in detail and need not be repeated.