CA1123696A - Low friction syringe - Google Patents
Low friction syringeInfo
- Publication number
- CA1123696A CA1123696A CA318,780A CA318780A CA1123696A CA 1123696 A CA1123696 A CA 1123696A CA 318780 A CA318780 A CA 318780A CA 1123696 A CA1123696 A CA 1123696A
- Authority
- CA
- Canada
- Prior art keywords
- barrel
- syringe
- plug
- chamber
- plunger
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/178—Syringes
- A61M5/31—Details
- A61M5/315—Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
- A61M5/31511—Piston or piston-rod constructions, e.g. connection of piston with piston-rod
- A61M5/31513—Piston constructions to improve sealing or sliding
Landscapes
- Health & Medical Sciences (AREA)
- Vascular Medicine (AREA)
- Engineering & Computer Science (AREA)
- Anesthesiology (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Hematology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
Abstract
LOW FRICTION SYRINGE
ABSTRACT OF THE DISCLOSURE
A low friction syringe comprising, a barrel defining a chamber, a plunger having a distal end received in the barrel chamber, and a plug of elastic material having a body portion secured to the distal end of the plunger. The plug has first and second annular flanges respectively extending forwardly and rearwardly from the body portion. The first and second flanges have an enlarged outer annular lip lightly contacting an inner surface of the barrel, and an annular hinge portion adjacent the body portion to permit flexation of the flanges responsive to differential pressures between a cavity intermediate the flanges and either the chamber or the atmosphere. The flanges also per-mit free movement of the plug in the chamber under relatively low friction between the plug and the syringe barrel.
ABSTRACT OF THE DISCLOSURE
A low friction syringe comprising, a barrel defining a chamber, a plunger having a distal end received in the barrel chamber, and a plug of elastic material having a body portion secured to the distal end of the plunger. The plug has first and second annular flanges respectively extending forwardly and rearwardly from the body portion. The first and second flanges have an enlarged outer annular lip lightly contacting an inner surface of the barrel, and an annular hinge portion adjacent the body portion to permit flexation of the flanges responsive to differential pressures between a cavity intermediate the flanges and either the chamber or the atmosphere. The flanges also per-mit free movement of the plug in the chamber under relatively low friction between the plug and the syringe barrel.
Description
3~6 BACKGROUND OF THE INVENTION
The present invention relates to syringes, and more particularly to syringes which are useful for certain medical procedures.
In recent years, gas analysis of arterial blood has become one of the most important laboratory tests in the manage-ment of patients with respiratory and metabolic disorders. How-ever, the collection of a satisfactory arterial blood sample from a patient for analysis has posed a number of difficulties.
Initially, in some patients it may be somewhat difficult to ascertain whether the collection device has received arterial or venous blood without measuring for the relatively high arter-ial pressures during collection. Second, the collection device should minimize contact of the blood sample with air since the air may affect the results of gas analysis. It is also desirable that the sample should not be collected in the presence of a vacuum, since it is believed that the vacuum may modify the gas characteristics of the sample. Finally, the device must prevent coagulation of the blood sample, and should be in a suitable form ~0 to permit closure of the sample to air and chilling during the period of time between collection and analysis.
In the past, plastic and ground glass syringes with a needle have been commonly used to collect the samples. However, prior syringes with rubber plugs of conventional design have proven deficient for such purposes due to the relatively high resistance between the syringe plunger and barrel. The plunger resistance in conventional plastic syringes prevents movement of the plunger responsive to arterial pressure alone, and requires that the plunger be manually withdrawn, thus creating an undesir-able vacuum in the syringe chamber during collection. Further, ,~
~ ~ Z3~
since the plungers of such plastic syringes are not sufficiently mobile to move under arterial pressure, they do not provide an indication whether arterial or venous blood is being collected.
Although the plungers of the ground glass syringes may be used to detect arterial pressure, the ground glass syringes are exces-sively expensive relative the plastic syringes.
During other medical procedures, such as an epidural anesthesia procedure, it is necessary to position the tip of a needle at a relatively precise position inside the patient's body. During this particular procedure, the needle tip should ~e located in the po~ential epidural space where the body pres-sure during insertion of the needle is normally slightly nega-tive. If the needle tip has been advanced too far into the body, it projects through the dura mater into the subarachnoid space where the body pressure is positive. A ground glass syringe may be utilized in this procedure to determine the location of the needle tip through use of the relative body pressures, but con-ventional plastic syringes have not been sufficiently responsive to pressures for this purpose. Since syringes are normally con-?0 sidered a disposable item, it is desirable to reduce their costto the hospital and patient below that of the relatively expen-sive ground glass syringes.
SUMMAR~ OF THE INVENTION
A principal feature of the present invention is the provision of an improved syringe of simplified construction and reduced cost.
The syringe of the present invention comprises, a barrel having an inner surface defining a chamber, a plunger having a distal end received in the barrel chamber, and a plug of elastic material received in the chamber and having a body portion secured l~ ~3~i~96 to the distal end of the plunger. ~he plug has a first annular flange extending forwardly from the body portion, with the first flange having an enlarged outer annular lip lightly contacting the inner surface of the barrel, and an annular hinge portion adjacent the body portion of reduced thickness relative the thickness of the lip. The plug has a second annular flange extending rearwardly from the body portion, with the second flange having an enlarged outer annular lip lightly contacting the inner surface of the barrel, and an annular hinge portion adjacent the body portion of reduced thickness relative the thickness of the second flange lip, with the first and second flanges defining an annular cavity intermediate the body portion and the barrel.
A feature of the present invention is that the plug flanges have minimal resistance for the syringe barrel to permit relatively free movement of the plug and plunger in the barrel.
Another feature of the invention is that the first flange flexes against the inner surface of the barrel responsive to a slightly greater pressure in the chamber relative the cavity during forward movement of the plunger in the barrel.
Thus, a feature of the invention is that a seal is accomplished in the syringe while pumping fluid out of the cham-ber.
Yet another feature of the invention is that the first flange flexes about its hinge away from the inner surface of the barrel responsive to a slightly less pressure in the chamber rela-tive the cavity, and the second flange flexes agai~st the inner surface of the barrel responsive to a slightly less pressure in the communicating chamber and cavity relative atmospheric pressure during rearward movement of the plunger in the barrel.
3~6 Accordingly, still another feature of the invention is that a seal is accomplished ~hrough cooperation of the first and second flanges during aspiration by the syringe.
A further feature of the invention is that the syringe may be constructed at a reduced cost while providing minimal friction of plunger movement normally accomplished by relatively expensive precision ground glass syringes.
Further features will become more fully apparent in the following description of the embodiments of this invention and from the appended claims.
DESCRIPTION OF THE DR~WINGS
In the drawings:
Fig. 1 is an elevational view, partly broken away, of a low friction syringe of the present invention;
Fig. 2 is a fragmentary sectional view of the syringe of Fig. l;
Fig. 3 is a fragmentary sectional view illustrating use of the syringe during forward movement of a syringe plunger and plug in a chamber of the syringe;
Fig. 4 is a fragmentary sectional view illustrating use o the syringe during rearward movement of the syringe plunger and plug in the chamber; and Fig. 5 is an elevational view, taken partly in section, of another embodiment of the syringe of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Figs. 1 and 2, there is shown a syr-inge generally designated 10 having a barrel 12, an elongated plunger 14, and a plug 16 of elastic material secured to a dis-.
The present invention relates to syringes, and more particularly to syringes which are useful for certain medical procedures.
In recent years, gas analysis of arterial blood has become one of the most important laboratory tests in the manage-ment of patients with respiratory and metabolic disorders. How-ever, the collection of a satisfactory arterial blood sample from a patient for analysis has posed a number of difficulties.
Initially, in some patients it may be somewhat difficult to ascertain whether the collection device has received arterial or venous blood without measuring for the relatively high arter-ial pressures during collection. Second, the collection device should minimize contact of the blood sample with air since the air may affect the results of gas analysis. It is also desirable that the sample should not be collected in the presence of a vacuum, since it is believed that the vacuum may modify the gas characteristics of the sample. Finally, the device must prevent coagulation of the blood sample, and should be in a suitable form ~0 to permit closure of the sample to air and chilling during the period of time between collection and analysis.
In the past, plastic and ground glass syringes with a needle have been commonly used to collect the samples. However, prior syringes with rubber plugs of conventional design have proven deficient for such purposes due to the relatively high resistance between the syringe plunger and barrel. The plunger resistance in conventional plastic syringes prevents movement of the plunger responsive to arterial pressure alone, and requires that the plunger be manually withdrawn, thus creating an undesir-able vacuum in the syringe chamber during collection. Further, ,~
~ ~ Z3~
since the plungers of such plastic syringes are not sufficiently mobile to move under arterial pressure, they do not provide an indication whether arterial or venous blood is being collected.
Although the plungers of the ground glass syringes may be used to detect arterial pressure, the ground glass syringes are exces-sively expensive relative the plastic syringes.
During other medical procedures, such as an epidural anesthesia procedure, it is necessary to position the tip of a needle at a relatively precise position inside the patient's body. During this particular procedure, the needle tip should ~e located in the po~ential epidural space where the body pres-sure during insertion of the needle is normally slightly nega-tive. If the needle tip has been advanced too far into the body, it projects through the dura mater into the subarachnoid space where the body pressure is positive. A ground glass syringe may be utilized in this procedure to determine the location of the needle tip through use of the relative body pressures, but con-ventional plastic syringes have not been sufficiently responsive to pressures for this purpose. Since syringes are normally con-?0 sidered a disposable item, it is desirable to reduce their costto the hospital and patient below that of the relatively expen-sive ground glass syringes.
SUMMAR~ OF THE INVENTION
A principal feature of the present invention is the provision of an improved syringe of simplified construction and reduced cost.
The syringe of the present invention comprises, a barrel having an inner surface defining a chamber, a plunger having a distal end received in the barrel chamber, and a plug of elastic material received in the chamber and having a body portion secured l~ ~3~i~96 to the distal end of the plunger. ~he plug has a first annular flange extending forwardly from the body portion, with the first flange having an enlarged outer annular lip lightly contacting the inner surface of the barrel, and an annular hinge portion adjacent the body portion of reduced thickness relative the thickness of the lip. The plug has a second annular flange extending rearwardly from the body portion, with the second flange having an enlarged outer annular lip lightly contacting the inner surface of the barrel, and an annular hinge portion adjacent the body portion of reduced thickness relative the thickness of the second flange lip, with the first and second flanges defining an annular cavity intermediate the body portion and the barrel.
A feature of the present invention is that the plug flanges have minimal resistance for the syringe barrel to permit relatively free movement of the plug and plunger in the barrel.
Another feature of the invention is that the first flange flexes against the inner surface of the barrel responsive to a slightly greater pressure in the chamber relative the cavity during forward movement of the plunger in the barrel.
Thus, a feature of the invention is that a seal is accomplished in the syringe while pumping fluid out of the cham-ber.
Yet another feature of the invention is that the first flange flexes about its hinge away from the inner surface of the barrel responsive to a slightly less pressure in the chamber rela-tive the cavity, and the second flange flexes agai~st the inner surface of the barrel responsive to a slightly less pressure in the communicating chamber and cavity relative atmospheric pressure during rearward movement of the plunger in the barrel.
3~6 Accordingly, still another feature of the invention is that a seal is accomplished ~hrough cooperation of the first and second flanges during aspiration by the syringe.
A further feature of the invention is that the syringe may be constructed at a reduced cost while providing minimal friction of plunger movement normally accomplished by relatively expensive precision ground glass syringes.
Further features will become more fully apparent in the following description of the embodiments of this invention and from the appended claims.
DESCRIPTION OF THE DR~WINGS
In the drawings:
Fig. 1 is an elevational view, partly broken away, of a low friction syringe of the present invention;
Fig. 2 is a fragmentary sectional view of the syringe of Fig. l;
Fig. 3 is a fragmentary sectional view illustrating use of the syringe during forward movement of a syringe plunger and plug in a chamber of the syringe;
Fig. 4 is a fragmentary sectional view illustrating use o the syringe during rearward movement of the syringe plunger and plug in the chamber; and Fig. 5 is an elevational view, taken partly in section, of another embodiment of the syringe of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Figs. 1 and 2, there is shown a syr-inge generally designated 10 having a barrel 12, an elongated plunger 14, and a plug 16 of elastic material secured to a dis-.
2~6 tal end 18 of the plunger 14. The syringe barrel 12 has an inner surface 20 defining a chamber 22, a tip 24 at a distal end 26 of the barrel, and a conventional leur lock 28 for securement of the syringe barrel to a suitable instrument, such as a needle (not shown).
With reference to Fig. 2, the plug 16 is s]idably received in the barrel chamber 22, and has a main body portion 34 defining a recess 30 which receives a boss 32 projecting for-wardly from the distal end 18 of the plunger 14 in order to secure the plug 16 onto the distal end 18 of the plunger. The plug 16 has a first annular flange 36 extending forwardly or dis-tally from the body portion 34 in the syringe chamber, with the first flange 36 having an enlarged outer annular lip 38 which lightly contacts the inner surface 20 of the syringe barrel 12, and an annular hinge portion 40 adjacent the body portion 34 and having a reduced thickness relative the thickness of the lip 38.
The plug 16 also has a second annular flange 42 extending rear-wardly or proximally from the body portion 34, with the second flange 42 having an enlarged outer annular lip 44 lightly con-tacting the inner surface 20 of the syringe barrel 12, and an annular hinge portion 46 of reduced thickness relative the thick-ness of the second flange lip 44. As shown, the first and sec-ond flanges 36 and 42 define an annular cavity 48 intermediate the body portion 34 and the inner surface 20 of the barrel 12.
The hinge portions 40 and 46 of the first and second flanges 36 and 42, respectively, permit ready flexation of the flanges relative the barrel 12, and under normal conditions cause slight contact of the respective flange lips 38 and 44 against the syringe barrel 12. As a result, the syringe plug has rela-tively low friction against movement in the barrel surface 20, ~ ~3~6 permitting free movement of the plunger and plug in the syringe barrel. Thus, the syringe of the present invention may be uti-lized in special medical procedures, such as collecting arterial blood or an epidural anest~esia procedure, where free movement of the syringe plunger in the barrel is re~uired, previously accom-plished by precision ground glass syringes. The syringe barrel 12 and plunger 14 may be made from relat~vely inexpensive plastic materials, such as polypropylene, while ~he syringe plug 16 may be constructed from inexpensive elastomers, such as polyisoprene rub-ber. Thus, the syringe of the present invention may be constructedin a simplified manner from inexpensive parts, while accomplishing results of relatively expensive ground glass syringes.
In addition to accomplishing this objective, the syr-inge plug 16 provides an effective seal for pumping and aspirat-ing fluids. With reference to Fig. 3, during forward pumpingmovement of the syringe plunger 14 in the barrel 12, the pressure in the syringe chamber 22 increases to an amount slightly greater than the pressure in the cavity 48, causing a differential pres-sure between the chamber 22 and cavity 48 and flexation of the first flange 36 into increased engagement against the inner sur-face 20 of the syringe barrel 12. As a result, the first flange 36 provides an effective seal for the plug 16 during pumping of fluids from the syringe chamber.
With reference to Fig. 4, when the syringe plunger is withdrawn slightly in a rearward direction in the chamber 22, dur-ing aspiration of fluids, the pressure in the chamber 22 decreases to an amount slightly less than the pressure in the cavity 48, causing inward flexation of the first flange 36 and lip 38 away from the inner surface 20 of the barrel 12 in order to establish communication between the chamber 22 and cavity 48. In this
With reference to Fig. 2, the plug 16 is s]idably received in the barrel chamber 22, and has a main body portion 34 defining a recess 30 which receives a boss 32 projecting for-wardly from the distal end 18 of the plunger 14 in order to secure the plug 16 onto the distal end 18 of the plunger. The plug 16 has a first annular flange 36 extending forwardly or dis-tally from the body portion 34 in the syringe chamber, with the first flange 36 having an enlarged outer annular lip 38 which lightly contacts the inner surface 20 of the syringe barrel 12, and an annular hinge portion 40 adjacent the body portion 34 and having a reduced thickness relative the thickness of the lip 38.
The plug 16 also has a second annular flange 42 extending rear-wardly or proximally from the body portion 34, with the second flange 42 having an enlarged outer annular lip 44 lightly con-tacting the inner surface 20 of the syringe barrel 12, and an annular hinge portion 46 of reduced thickness relative the thick-ness of the second flange lip 44. As shown, the first and sec-ond flanges 36 and 42 define an annular cavity 48 intermediate the body portion 34 and the inner surface 20 of the barrel 12.
The hinge portions 40 and 46 of the first and second flanges 36 and 42, respectively, permit ready flexation of the flanges relative the barrel 12, and under normal conditions cause slight contact of the respective flange lips 38 and 44 against the syringe barrel 12. As a result, the syringe plug has rela-tively low friction against movement in the barrel surface 20, ~ ~3~6 permitting free movement of the plunger and plug in the syringe barrel. Thus, the syringe of the present invention may be uti-lized in special medical procedures, such as collecting arterial blood or an epidural anest~esia procedure, where free movement of the syringe plunger in the barrel is re~uired, previously accom-plished by precision ground glass syringes. The syringe barrel 12 and plunger 14 may be made from relat~vely inexpensive plastic materials, such as polypropylene, while ~he syringe plug 16 may be constructed from inexpensive elastomers, such as polyisoprene rub-ber. Thus, the syringe of the present invention may be constructedin a simplified manner from inexpensive parts, while accomplishing results of relatively expensive ground glass syringes.
In addition to accomplishing this objective, the syr-inge plug 16 provides an effective seal for pumping and aspirat-ing fluids. With reference to Fig. 3, during forward pumpingmovement of the syringe plunger 14 in the barrel 12, the pressure in the syringe chamber 22 increases to an amount slightly greater than the pressure in the cavity 48, causing a differential pres-sure between the chamber 22 and cavity 48 and flexation of the first flange 36 into increased engagement against the inner sur-face 20 of the syringe barrel 12. As a result, the first flange 36 provides an effective seal for the plug 16 during pumping of fluids from the syringe chamber.
With reference to Fig. 4, when the syringe plunger is withdrawn slightly in a rearward direction in the chamber 22, dur-ing aspiration of fluids, the pressure in the chamber 22 decreases to an amount slightly less than the pressure in the cavity 48, causing inward flexation of the first flange 36 and lip 38 away from the inner surface 20 of the barrel 12 in order to establish communication between the chamber 22 and cavity 48. In this
3~
configuration, the pressures in both the communicating chamber 22 and cavity 48 become less than atmospheric pressure outside the plug 16, and the second flange 42 thus flexes against the inner surface 20 of the syringe barrel 12 into increased engage-ment to accomplish an effective seal during withdrawal o~ thesyringe plunger 14. In this manner, the plug 16 permits aspira-tion of fluids into the syringe chamber 22.
Thus, in accordance with the present invention, the syringe provides relatively free movement of the plunger and plug along the syringe barrel under conditions of relatively low friction between the plug and barrel in order to permit use of the syringe in special medical procedures, as previously des-cribed. Further, the syringe of the invention permits pumping and aspiration of fluids through flexation and cooperation of the plug flanges.
Another embodiment of the present invention is illus-trated in Fig. 5, in which like reference numerals designate like parts. In this embodiment, the syringe barrel 12 has an enlarged section 50 at a proximal end of the barrel which has an internal diameter greater than the outer diameter of the plug 16 includ-ing the flanges 36 and 42. The plug 16 may be positioned in the section 50 for extended storage prior to use in order to minimize contact of the plug 16 against the syringe barrel 12, and thus minimize the possibility that the plug ~langes may otherwise assume a set due to prolonged contact against the syringe barrel.
The foregoing detailed description is given for clear-ness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.
configuration, the pressures in both the communicating chamber 22 and cavity 48 become less than atmospheric pressure outside the plug 16, and the second flange 42 thus flexes against the inner surface 20 of the syringe barrel 12 into increased engage-ment to accomplish an effective seal during withdrawal o~ thesyringe plunger 14. In this manner, the plug 16 permits aspira-tion of fluids into the syringe chamber 22.
Thus, in accordance with the present invention, the syringe provides relatively free movement of the plunger and plug along the syringe barrel under conditions of relatively low friction between the plug and barrel in order to permit use of the syringe in special medical procedures, as previously des-cribed. Further, the syringe of the invention permits pumping and aspiration of fluids through flexation and cooperation of the plug flanges.
Another embodiment of the present invention is illus-trated in Fig. 5, in which like reference numerals designate like parts. In this embodiment, the syringe barrel 12 has an enlarged section 50 at a proximal end of the barrel which has an internal diameter greater than the outer diameter of the plug 16 includ-ing the flanges 36 and 42. The plug 16 may be positioned in the section 50 for extended storage prior to use in order to minimize contact of the plug 16 against the syringe barrel 12, and thus minimize the possibility that the plug ~langes may otherwise assume a set due to prolonged contact against the syringe barrel.
The foregoing detailed description is given for clear-ness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.
Claims (3)
1. A low friction syringe, comprising:
a barrel having an inner surface defining a chamber;
a plunger having a distal end received in the barrel chamber; and a plug of elastic material received in said chamber and having a body portion secured to said distal end of the plunger, said plug having a first annular flange extending forwardly from said body portion, said first flange having an enlarged outer annu-lar lip lightly contacting the inner surface of said barrel, and an annular hinge portion adjacent said body portion of reduced thickness relative the thickness of said lip, said plug having a second annular flange extending rearwardly from the body portion, said second flange having an enlarged outer annular lip lightly contacting the inner surface of said barrel, and an annular hinge portion adjacent said body portion of reduced thickness relative the thickness of the second flange lip, said first and second flanges defining an annular cavity intermediate the body portion and the barrel, said first flange flexing against the inner sur-face of the barrel responsive to a slightly greater pressure in the chamber relative the cavity during forward movement of the plunger in the barrel, and said first flange flexing about its hinge away from the inner surface of the barrel responsive to a slightly less pressure in the chamber relative the cavity and said second flange flexing against the inner surface of the barrel responsive to a slightly less pressure in the communicating cham-ber and cavity relative the pressure rearward the plug during rearward movement of the plunger in the barrel.
a barrel having an inner surface defining a chamber;
a plunger having a distal end received in the barrel chamber; and a plug of elastic material received in said chamber and having a body portion secured to said distal end of the plunger, said plug having a first annular flange extending forwardly from said body portion, said first flange having an enlarged outer annu-lar lip lightly contacting the inner surface of said barrel, and an annular hinge portion adjacent said body portion of reduced thickness relative the thickness of said lip, said plug having a second annular flange extending rearwardly from the body portion, said second flange having an enlarged outer annular lip lightly contacting the inner surface of said barrel, and an annular hinge portion adjacent said body portion of reduced thickness relative the thickness of the second flange lip, said first and second flanges defining an annular cavity intermediate the body portion and the barrel, said first flange flexing against the inner sur-face of the barrel responsive to a slightly greater pressure in the chamber relative the cavity during forward movement of the plunger in the barrel, and said first flange flexing about its hinge away from the inner surface of the barrel responsive to a slightly less pressure in the chamber relative the cavity and said second flange flexing against the inner surface of the barrel responsive to a slightly less pressure in the communicating cham-ber and cavity relative the pressure rearward the plug during rearward movement of the plunger in the barrel.
2. The syringe of claim 1 wherein said barrel and plunger are constructed from a plastic material.
3. The syringe of claim 1 wherein said barrel includes an enlarged section adjacent a rearward end of the barrel having an internal diameter slightly larger than the outer diameter of the first and second flanges.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86972978A | 1978-01-16 | 1978-01-16 | |
| US869,729 | 1978-01-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1123696A true CA1123696A (en) | 1982-05-18 |
Family
ID=25354152
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA318,780A Expired CA1123696A (en) | 1978-01-16 | 1978-12-28 | Low friction syringe |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1123696A (en) |
| GB (1) | GB2012590B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4339528C2 (en) * | 1993-11-19 | 1995-09-07 | Freudenberg Carl Fa | Disposable syringe |
| EP1024848A4 (en) * | 1997-10-23 | 2001-01-03 | Bristol Myers Squibb Co | Preloadable syringe for automated dispensing device |
| US6224577B1 (en) * | 1998-03-02 | 2001-05-01 | Medrad, Inc. | Syringes and plungers for use therein |
| CA2236049C (en) | 1998-04-27 | 2006-07-25 | Computer Controlled Syringe Inc. | Syringe with detachable syringe barrel |
-
1978
- 1978-12-28 CA CA318,780A patent/CA1123696A/en not_active Expired
-
1979
- 1979-01-09 GB GB7900771A patent/GB2012590B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2012590B (en) | 1982-06-16 |
| GB2012590A (en) | 1979-08-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |