CA2036940C - A syringe for dispensing measured quantities of a medicament - Google Patents
A syringe for dispensing measured quantities of a medicament Download PDFInfo
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- CA2036940C CA2036940C CA 2036940 CA2036940A CA2036940C CA 2036940 C CA2036940 C CA 2036940C CA 2036940 CA2036940 CA 2036940 CA 2036940 A CA2036940 A CA 2036940A CA 2036940 C CA2036940 C CA 2036940C
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- rail
- syringe
- rail section
- stop member
- stop
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Abstract
A disposable syringe (Figure 2, 10) for dispensing a metered dosage of a material includes a plunger rod (14) which is axially movable within a syringe barrel (12) for dispensing the material. The plunger rod (14) includes a rail section (18) located outside the syringe barrel (12), and a slidable stop member (16) is secured to the rail section (18) for adjusting the volume of material to be dispensed. The adjustable stop member (16) includes a knife edge (62) for embedding into a surface (32) of the rail section of the plunger rod (14) to lock the stop member (16) in a desired position.
Description
SYRINGE FOR DISPENSING MEASURED
QUANTITIES OF A MEDICAMENT
FIELD OF THE INVENTION
This invention relates generally to syringes, and more specifically to a syringe for dispensing measured quantities of a material. (e. g., a medicament) and which employs a unique arrangement for setting the desired measured quantity to be dispensed.
BACKGROUND ART
It is 'well known in the prior art to provide syringes with movable stop members forming a part of .10 the plunger rod, for the purpose of permitting the setting of the desired do>sage to be dispensed. These syringes are widely used in dispersing medicaments, particularly in the veterinary fie.l.d.
One cocnmon prior art design for adjusting the 15 dosage to be dispensed employs a threaded nut cooperating with threads on the exterior surface of the plunger rod to permit the nut to be adjusted along the length of the rod to a desired, spaced positiion from an outer marginal surfac.~ of the syringe barrel. Upon 20 depression of the plunger rod, for the purpose of dispensing a medicament from the syringe barrel, the nut will engage the outer margin of the barrel to control the quantity of medicament dispensed from the syringe. Typical syringes employing a rotary nut are 25 disclosed in U.S. Patent Nos. 475,909, issued to
QUANTITIES OF A MEDICAMENT
FIELD OF THE INVENTION
This invention relates generally to syringes, and more specifically to a syringe for dispensing measured quantities of a material. (e. g., a medicament) and which employs a unique arrangement for setting the desired measured quantity to be dispensed.
BACKGROUND ART
It is 'well known in the prior art to provide syringes with movable stop members forming a part of .10 the plunger rod, for the purpose of permitting the setting of the desired do>sage to be dispensed. These syringes are widely used in dispersing medicaments, particularly in the veterinary fie.l.d.
One cocnmon prior art design for adjusting the 15 dosage to be dispensed employs a threaded nut cooperating with threads on the exterior surface of the plunger rod to permit the nut to be adjusted along the length of the rod to a desired, spaced positiion from an outer marginal surfac.~ of the syringe barrel. Upon 20 depression of the plunger rod, for the purpose of dispensing a medicament from the syringe barrel, the nut will engage the outer margin of the barrel to control the quantity of medicament dispensed from the syringe. Typical syringes employing a rotary nut are 25 disclosed in U.S. Patent Nos. 475,909, issued to
-2-Wilcox; 3,563,240, issued to Silver; 4,246,898. issued to Trava.lent, et al; 4,153,056, issued to Silver, et al.; and British Patent No. 1.,212,823, issued to Silver.
A problem encountered in the prior art systems employing rotating nuts, other than the system described in the Silver Patent No. 4, 57.3, 056. p s that the plunger rod of the syringe must be made in two sections in order to permit the nut to be inserted over the rod, as it cannot f it over the p7.unger seal at the end which is necessarily wider than the rod. This increases the manufacturing, material. and assembly costs, as compared to a system in which the plunger rod and plunger seal are made as a one-piece unit. The device disclosed in the aforementioned Silver '056 7_5 patent does not suffer from this deficiency because the ring structure is of a split construction, and is designed to be inserted over the one-piece plunger rod in a direction laterally of the longitudinal axis of said rod.
In the construction disclosed in the Silver '056 patent the adjustable nut can be a one-piece, hinged element having two adjacent open end portions that can be secured to each other to form a comp.l.ete annular nut. Alternatively, the adjustable member can be made of two separate pieces which can be placed around the stem and fastened together. A split ring construction
A problem encountered in the prior art systems employing rotating nuts, other than the system described in the Silver Patent No. 4, 57.3, 056. p s that the plunger rod of the syringe must be made in two sections in order to permit the nut to be inserted over the rod, as it cannot f it over the p7.unger seal at the end which is necessarily wider than the rod. This increases the manufacturing, material. and assembly costs, as compared to a system in which the plunger rod and plunger seal are made as a one-piece unit. The device disclosed in the aforementioned Silver '056 7_5 patent does not suffer from this deficiency because the ring structure is of a split construction, and is designed to be inserted over the one-piece plunger rod in a direction laterally of the longitudinal axis of said rod.
In the construction disclosed in the Silver '056 patent the adjustable nut can be a one-piece, hinged element having two adjacent open end portions that can be secured to each other to form a comp.l.ete annular nut. Alternatively, the adjustable member can be made of two separate pieces which can be placed around the stem and fastened together. A split ring construction
-3-has proven to be not well. suited for use in dispensing high.l.y viscous, pasty substances, wherein high pressures need to be imparted to the plunger rod to dispense the substance. Under such high pressure operation the split ring pops off the plunger rod or has actua.l.ly fractured when pressed against the syringe barrel..
There are several ways disc.l.osed for adjusting the dosage to be dispensed in the dispenser described in the Silver '056 patent. One way is to rotate the nut axially along the plunger rod, through cooperating threads on the nut. and the rod. In an alternative embodiment the plunger rod can have a smooth, unthreaded surface, and the nut can be engaged with the plunger rod solely by friction, in which case the nut can be slid (i.e., without rotation) along the rod to a desired location. In this latter embodiment there is no positive means for retaining the nut in its set position to prevent. undesired, inadvertent displacement of the nut along the rod. An additional mode of adjusting the nut on the rod, and one which is suggested when the position of the nut on the rod is a substantial distance from its desired position, is to physically remove the split or hinged nut from the rod and replace it adjacent its desired location. This latter method of adjusting the dosage requires the _Q_ disassembly arid reassembly of the nut with the rod; a pracedure which is somewhat camplex and undesirable.
A.l.though the use of a solid threaded nut for setting the dosage e.liminate.s the problems encountered with the slit ring arrangement, a solid nut presents other deficiencies which increase the cost of manufacture, assembly and use of the syringe. First, if a person wants to dispense a large percentage (e.g-500, or even 7.00$) of the material in the barrel, it is necessary to rotate the nut a substantial distance along the piston rod, from its initial position adjacent the end of the syringe barrel, where it is required to be located initially, to lock the plunger rod so that it will. not inadvertently be moved to dispense the material in the barrel. Second, when the syringe barrel is pre.fill.ed in automated equipment it is necessary to rotate the nut to the upstream end of the plunger rod, adjacent the thumb pad, so that the nut will not interfere with the filling and venting of the syringe barrel. After the syringe barrel has been filled the continuous nut must be restated in the opposite, or downstream direction along the plunger rod to the marginal end of the syringe body to thereby lock the plunger rod against inadvertent movement into the syringe barrel, which, if permitted to occur, wauld result in the inadvertent dispensing of the material _5_ from the barrel.. The need to manipulate or adjust the nut along the plunger rod, as described above, adds undesired cost to the manufacturing and assembly operations.
It also has been suggested in the prior art to employ a stop member which is adapted to be slid along the .length of the rod of a syringe into a desired notch in the rod, for the purpose of setting the desired dosage to be dispensed. Representative devices of this type are disclosed in U.S. Patent Nos. 4,642,102, issued to Ohmori, and .1,852,658, issued to Ki.le. These devices do not permit infinite adjustment of the dosage to be dispensed, since they require the stop member to be positively located in a preformed notch.
In summary, the prior art syringes for dispensing measured quantities of a medicament generally have been considered to be unreliab7.e in setting and maintaining the desired dosage to be dispensed, to lack the desired flexibility in adjusting the dosage within very narrow limits, to be too cumbersome to handle in assembly before and during filling of the syringe body, and to be more costly to manufacture.
SUMMARY OF THE INVENTION
The objects of this invention are achieved in a syringe for dispensing a metered dosage of a.material (e. g., a medicament) including a hollow syringe barrel for containing the material to be dispensed and having a discharged end portion and an open opposite end portion, through which the material to be dispensed is introduced and into which a plunger rod is slidably received. The plunger rod includes a rail section and an axially adjustable stop member engaged with the rail section outside the syringe barrel to limit the linear travel of the plunger rod into the syringe barrel. As a result of this arrangement the volume of material dispensed from said syringe barrel is controlled.
In accordance with this invention the axially adjustable stop member includes a knife edge for digging or embedding into a surface of the rail portion of the piston rod, to thereby positively lock the stop member in a fixed position on the rail section for limiting the axial movement of the plunger rod into the syringe barrel for dispensing the , desired dosage of material.
More specifically, the present invention provides a syringe for dispensing a predetermined dosage of material comprising a hollow barrel having a discharge end from which the material can be dispensed and an open, opposite end.
The syringe further comprises a plunger rod slidably received in said barrel through the open, opposite ends the plunger rod including a rail section having at least a portion thereof located outside of the barrel, and the plunger rod being movable in a downstream direction into the barrel for dispensing the material.
The syringe also comprises a stop mounted for movement along the length of the rail section engageable by the barrel to establish the length of travel of the plunger rod in the downstream direction for controlling the volume of material to be dispensed; the stop being selectively fixedly engageable with the rail section at any one of an infinite number of desired positions to lock the stop in a desired position on said rail section.
The stop includes a knife edge selectively movable between a first position disengaged from the rail section and a second position embedded into the rail section at a precise desired location therealong; the stop further including a downstream surface for engaging a surface of the syringe barrel at the open end of the barrel when the plunger rod has been moved in a downstream direction to dispense a desired volume of material.
The stop is pivotally secured to the plunger rod, whereby engagement of the downstream surface of the stop with the surface of the syringe barrel at the open end of the barrel forces the stop to pivot in a direction for aiding in embedding the knife edge of the stop into the rail section of the plunger rod.
According to the present invention, the axially adjustable stop member is secured to the plunger rod for both axial and pivotal movement. The pivotal movement of the stop member is relied upon to drive the knife edge thereof into the plunger rod for the purpose of positively locking the stop member in a desired, adjusted position on said rod.
- 6a -2~~~~
_, _ In accordance with a preferred embodiment of this invention the adjustable stop member engages a surface of the syringe barrel adjacent the open end thereof when the desired dosage has been dispensed, and this engagement imparts a force on the stop member to compliment the locking action provided between the knife edge and the rod. In fact, the harder one depresses the plunger when the stop member is in engagement with the surface of the syringe barrel adjacent the open end thereof, the more deeply the knife edge of the stop member embeds into the piston rod, to thereby prevent the overriding and inadvertent dispensing of an undesired, excessive dosage.
In another embodiment of this invention the axially adjustable stop member is in the farm of a clip having transversely spaced-apart marginal ends. These marginal ends include slots with knife edges therein far receiving sections of the plunger rod. The knife edges in the slots are biased in a direction to dig into or embed in confronting surfaces of the plunger rod. The clip further includes actuating means to release the engagement of the knife edges from the rod, to permit the stop member to be axially moved along the rod for setting the desired dosage to be dispensed.
In the preferred embodiments of this invention the adjustable stop member is snapped into engagement with _$_ the rod in a transverse direction (e. g., in a direction substantially 90 degrees to the direction of axial movement of the rod within the syringe barre.l).
BRIEF DESCRIPTION OF TFIE DRAWINGS
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Figure 1 is an isometric view of the syringe of this invention, illustrating, in phantom representa-tion, the manner in which it is gripped for dispensing a desired dosage of material. therefrom;
Figure 2 is an enlarged sectional view taken along line 2-2 of Figure .1;
Figure 3 is an en7.arged fragmentary side eleva tional view, showing the cooperation among the syringe barrel, the plunger rod and the adjustable stop member, when a desired, preset dosage of mat.eria.l has been dispensed from the syringe;
Figure 4 is an enlarged sectional. view taken along line 4-4 of Figure 2;
Figure 5 is an enlarged fragmentary sectional view of the syringe showing a modified stop member in accordance with this invention;
Figure 6 is an enlarged sectional view taken along line 6-6 of Figure 5; and Figure 7 is an enlarged sectional view taken along line 7-7 of Figure 6.
DESCRIPTION OF THE PREFERRED
EMBODIMENTS OF TIIE INVENTION
Referring now in greater detail to the various figures of the drawings, wherein like reference characters refer to like parts, a syringe for dispensing a metered dosage of material and embodying the present invention is generally shown at 10 in Figure .1. The device 10 basically comprises a syringe barrel 12 having a discharge end portion through which a medicament is dispensed and an open opposite end portion through which the medicament is introduced, a plunger rod 14 inserted within the open opposite end portion of the syringe barrel for dispensing material through the discharge end portion of the syringe barrel, and an axial.l.y, infinitely adjustable stop member 16 secured to the plunger rod for positively setting the length of travel of the plunger rod to thereby control the volume of material dispensed from the syringe.
Referring specifica.ll.y to Figure 2, the plunger rod 14 preferably is an unitary molded member including a rail section 18 and a piston section 20. The piston ~v ~~. ~~
section includes a plunger se al. 23 and a radially enlarged region 2.1, both of which fractiona7..l.y Engage the inner wall. of the syringe barrel 12. This enlarged region 21 stabilizes the plunger rod 14 for linear movement within the syringe barrel 12 to thereby prevent the plunger rod from tilting, which would allow leakage past the plunger seal 23.
Referring to Figures 2 and 4, the rail section 18 is cruciform in transverse cross-section, including four rails 22, 24, 26 and 28. An elongate slot 30 is formed through at .least one of the rai.l.s (e.g., 22) in a region inwardly of the outer surface 32 thereof. As can be seen best in Figure 2, the outer surface 32 is substantially planar (but could also be a linear edge surface), and is free of notches and/or other stop member-retaining grooves. It is this feature which permits universal, infinite adjustment of the stop member on the plunger rod 14, within the finite distance of the elongate slot 30.
Referring to Figures l., 2 and 4, the axially adjustable stop member 1.6 is infinite.l.y variable along the length of the rail 22 on which it is mounted, and includes transversely spaced-apart legs 42 and 44 which straddle said rail. The lower end of the legs include inwardly directed, generally spherical projections 46 (Figure 4) which snap-fit into the elongate slot 30.
2~~ i~~~
-ll.-In this manner the stop member 7.6 is firmly retained for sliding movement on the rail 22. In addition, the cooperation between the slot 30 and spherical projections 46 permits pivotal movement of the stop member on the rail. to assist in locking the stop member 16 on a desired dose .line of a calibrated sc:al.e, in a manner which will. be described in greater detail hereinafter. However, at this point it should be noted that the recess between the t.ransversel.y spaced-apart legs 42 and 44 includes a base 52 which is spaced radial.ly outwardly of the outer surface 32 of rail 22 when the spherical. projections 46 .are retained within the elongate slot 30. Tt is this spacing that permits the pivotal movement between the stop member 1.6 and the rail 22 to take place.
Referring specifically to Figures 1 and 2, the slidable stop member 16 also includes a pair of transversely spaced-apart legs 54 and 56 at the trailing, or upstream, end thereof. These latter legs axe shorter in length than the legs 42 and 44, primarily because they do not need to cooperate with the elongate slot 30. However, these transversely spaced-apart legs 54 and 56 do cooperate with the transversely spaced-apart legs 42 and 44 to stabilize the stop member on the rail 22 so that it can be smoothly and easily slid along the rail.
-.12-Sti.l.l referring to Figures 1 and 2, the stop member .16 includes a cutting or knife edge 62 extending downwardly and rearward.ly .from a rear wall thereof far embedding into the outer surface 32 of the rail. This embedding action results in the effective locking of the stop member in any desired position on the rail, within the axial confines of the slot .30. That is, the stop member 16 can be axial.l.y moved along the entire length of the elongate slot 30 and be locked in any position along its length of travel by causing the cutting edge 62 thereof to embed into the outer edge surface 32 of the rail 22.
Referring specifically to Figures .1-.3, the stop member 16 preferably includes a generally concave groove or surface 63 in the upper surface thereof which can be engaged by a user's thumb or finger to slide the stop member to a desired position on the rail section 18 for the purpose of setting the dosage which is to be administered from the syringe 7Ø To accomplish this result a volumetric sc ale 64 is provided on a rail 28 of the plunger rod 14 which is adjacent and at right angles to the rail upon which the stop member 16 is mounted. An indicator line 66 is provided on each of the transversely spaced-apart legs 42 and 44 of the stop member 16 for the purpose of permitting the setting of the stop member on the p.ropeY dose line of -.13-the volumetric scale to dispense a desired volume of material from the syringe.
After the stop member 16 teas been slid to the desired position on the rail, the rear or upstream end of the stop member can be manua.l.ly pressed downwardl.y, in the direction indicated by arrow 67 in Figure 2, to force the cutting edge 62 to embed into the upper surface of the rail. This action locks the stop member in proper position on the r ail section 18 of the ~,lunger rod 14.
After the stop member 16 has been set to permit the syringe to dispense a desired dosage, as is illustrated in Figures 1 and 2, the thumb pad of plunger 14 is pressed axially inwardly in a downstream direction, as is indicated by arrow 68 in Figure 3, to dispense the desired volume of material.
Referring specifically to Figures 2 and 3, the stop member 16 includes a generally planar wall 70 at the downstream end thereof for engaging the generally planar surface 7.1 of the annular flange 72 located at the open upstream end of the syringe barrel 12 when the plunger rod 14 has been moved the precise distance for dispensing the desired volume of material from the syringe. In view of the fact that the wall 70 of the stop member 16 engages planar surface 71 of the syringe barrel 12 in a region radially outwardly of the pivot r . i ~, ;f.
axis for the stop member .16, the force imposed upon the stop member by this engagement will cause the stop member to rotate in the general direction indicated by arrow 74. This rotational movement causes the upstream or rear end of the stop member to move downwardly in the general direction of arrow 75 to enhance the locking action provided by the cutting edge 62 embedding into the outer surface 32 of the rail 22. In other words, the force imposed upon the stop member 16 at a point in time when the desired volume of material has been dispensed is in a direction to compliment the locking action between the stop member 16 and the rail section 18 of the plunger rod 14. This is an extremely important and desirable feature in the present invention since it prevents the inadvertent unlocking of the stop member from the rail section 18 which, if permitted to occur, could result in the dispensing of an undesired dosage from the syringe.
When it is desired to reset the stop member 16 after its first use for the purpose of dispensing a second desired dosage, the plunger 14 is first pulled outwardly to disengage the planar wall 70 of the stop member from the generally planar surface 71 of the annular flange 72. The resulting clearance is required to permit the stop member 16 to be rotated for the
There are several ways disc.l.osed for adjusting the dosage to be dispensed in the dispenser described in the Silver '056 patent. One way is to rotate the nut axially along the plunger rod, through cooperating threads on the nut. and the rod. In an alternative embodiment the plunger rod can have a smooth, unthreaded surface, and the nut can be engaged with the plunger rod solely by friction, in which case the nut can be slid (i.e., without rotation) along the rod to a desired location. In this latter embodiment there is no positive means for retaining the nut in its set position to prevent. undesired, inadvertent displacement of the nut along the rod. An additional mode of adjusting the nut on the rod, and one which is suggested when the position of the nut on the rod is a substantial distance from its desired position, is to physically remove the split or hinged nut from the rod and replace it adjacent its desired location. This latter method of adjusting the dosage requires the _Q_ disassembly arid reassembly of the nut with the rod; a pracedure which is somewhat camplex and undesirable.
A.l.though the use of a solid threaded nut for setting the dosage e.liminate.s the problems encountered with the slit ring arrangement, a solid nut presents other deficiencies which increase the cost of manufacture, assembly and use of the syringe. First, if a person wants to dispense a large percentage (e.g-500, or even 7.00$) of the material in the barrel, it is necessary to rotate the nut a substantial distance along the piston rod, from its initial position adjacent the end of the syringe barrel, where it is required to be located initially, to lock the plunger rod so that it will. not inadvertently be moved to dispense the material in the barrel. Second, when the syringe barrel is pre.fill.ed in automated equipment it is necessary to rotate the nut to the upstream end of the plunger rod, adjacent the thumb pad, so that the nut will not interfere with the filling and venting of the syringe barrel. After the syringe barrel has been filled the continuous nut must be restated in the opposite, or downstream direction along the plunger rod to the marginal end of the syringe body to thereby lock the plunger rod against inadvertent movement into the syringe barrel, which, if permitted to occur, wauld result in the inadvertent dispensing of the material _5_ from the barrel.. The need to manipulate or adjust the nut along the plunger rod, as described above, adds undesired cost to the manufacturing and assembly operations.
It also has been suggested in the prior art to employ a stop member which is adapted to be slid along the .length of the rod of a syringe into a desired notch in the rod, for the purpose of setting the desired dosage to be dispensed. Representative devices of this type are disclosed in U.S. Patent Nos. 4,642,102, issued to Ohmori, and .1,852,658, issued to Ki.le. These devices do not permit infinite adjustment of the dosage to be dispensed, since they require the stop member to be positively located in a preformed notch.
In summary, the prior art syringes for dispensing measured quantities of a medicament generally have been considered to be unreliab7.e in setting and maintaining the desired dosage to be dispensed, to lack the desired flexibility in adjusting the dosage within very narrow limits, to be too cumbersome to handle in assembly before and during filling of the syringe body, and to be more costly to manufacture.
SUMMARY OF THE INVENTION
The objects of this invention are achieved in a syringe for dispensing a metered dosage of a.material (e. g., a medicament) including a hollow syringe barrel for containing the material to be dispensed and having a discharged end portion and an open opposite end portion, through which the material to be dispensed is introduced and into which a plunger rod is slidably received. The plunger rod includes a rail section and an axially adjustable stop member engaged with the rail section outside the syringe barrel to limit the linear travel of the plunger rod into the syringe barrel. As a result of this arrangement the volume of material dispensed from said syringe barrel is controlled.
In accordance with this invention the axially adjustable stop member includes a knife edge for digging or embedding into a surface of the rail portion of the piston rod, to thereby positively lock the stop member in a fixed position on the rail section for limiting the axial movement of the plunger rod into the syringe barrel for dispensing the , desired dosage of material.
More specifically, the present invention provides a syringe for dispensing a predetermined dosage of material comprising a hollow barrel having a discharge end from which the material can be dispensed and an open, opposite end.
The syringe further comprises a plunger rod slidably received in said barrel through the open, opposite ends the plunger rod including a rail section having at least a portion thereof located outside of the barrel, and the plunger rod being movable in a downstream direction into the barrel for dispensing the material.
The syringe also comprises a stop mounted for movement along the length of the rail section engageable by the barrel to establish the length of travel of the plunger rod in the downstream direction for controlling the volume of material to be dispensed; the stop being selectively fixedly engageable with the rail section at any one of an infinite number of desired positions to lock the stop in a desired position on said rail section.
The stop includes a knife edge selectively movable between a first position disengaged from the rail section and a second position embedded into the rail section at a precise desired location therealong; the stop further including a downstream surface for engaging a surface of the syringe barrel at the open end of the barrel when the plunger rod has been moved in a downstream direction to dispense a desired volume of material.
The stop is pivotally secured to the plunger rod, whereby engagement of the downstream surface of the stop with the surface of the syringe barrel at the open end of the barrel forces the stop to pivot in a direction for aiding in embedding the knife edge of the stop into the rail section of the plunger rod.
According to the present invention, the axially adjustable stop member is secured to the plunger rod for both axial and pivotal movement. The pivotal movement of the stop member is relied upon to drive the knife edge thereof into the plunger rod for the purpose of positively locking the stop member in a desired, adjusted position on said rod.
- 6a -2~~~~
_, _ In accordance with a preferred embodiment of this invention the adjustable stop member engages a surface of the syringe barrel adjacent the open end thereof when the desired dosage has been dispensed, and this engagement imparts a force on the stop member to compliment the locking action provided between the knife edge and the rod. In fact, the harder one depresses the plunger when the stop member is in engagement with the surface of the syringe barrel adjacent the open end thereof, the more deeply the knife edge of the stop member embeds into the piston rod, to thereby prevent the overriding and inadvertent dispensing of an undesired, excessive dosage.
In another embodiment of this invention the axially adjustable stop member is in the farm of a clip having transversely spaced-apart marginal ends. These marginal ends include slots with knife edges therein far receiving sections of the plunger rod. The knife edges in the slots are biased in a direction to dig into or embed in confronting surfaces of the plunger rod. The clip further includes actuating means to release the engagement of the knife edges from the rod, to permit the stop member to be axially moved along the rod for setting the desired dosage to be dispensed.
In the preferred embodiments of this invention the adjustable stop member is snapped into engagement with _$_ the rod in a transverse direction (e. g., in a direction substantially 90 degrees to the direction of axial movement of the rod within the syringe barre.l).
BRIEF DESCRIPTION OF TFIE DRAWINGS
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Figure 1 is an isometric view of the syringe of this invention, illustrating, in phantom representa-tion, the manner in which it is gripped for dispensing a desired dosage of material. therefrom;
Figure 2 is an enlarged sectional view taken along line 2-2 of Figure .1;
Figure 3 is an en7.arged fragmentary side eleva tional view, showing the cooperation among the syringe barrel, the plunger rod and the adjustable stop member, when a desired, preset dosage of mat.eria.l has been dispensed from the syringe;
Figure 4 is an enlarged sectional. view taken along line 4-4 of Figure 2;
Figure 5 is an enlarged fragmentary sectional view of the syringe showing a modified stop member in accordance with this invention;
Figure 6 is an enlarged sectional view taken along line 6-6 of Figure 5; and Figure 7 is an enlarged sectional view taken along line 7-7 of Figure 6.
DESCRIPTION OF THE PREFERRED
EMBODIMENTS OF TIIE INVENTION
Referring now in greater detail to the various figures of the drawings, wherein like reference characters refer to like parts, a syringe for dispensing a metered dosage of material and embodying the present invention is generally shown at 10 in Figure .1. The device 10 basically comprises a syringe barrel 12 having a discharge end portion through which a medicament is dispensed and an open opposite end portion through which the medicament is introduced, a plunger rod 14 inserted within the open opposite end portion of the syringe barrel for dispensing material through the discharge end portion of the syringe barrel, and an axial.l.y, infinitely adjustable stop member 16 secured to the plunger rod for positively setting the length of travel of the plunger rod to thereby control the volume of material dispensed from the syringe.
Referring specifica.ll.y to Figure 2, the plunger rod 14 preferably is an unitary molded member including a rail section 18 and a piston section 20. The piston ~v ~~. ~~
section includes a plunger se al. 23 and a radially enlarged region 2.1, both of which fractiona7..l.y Engage the inner wall. of the syringe barrel 12. This enlarged region 21 stabilizes the plunger rod 14 for linear movement within the syringe barrel 12 to thereby prevent the plunger rod from tilting, which would allow leakage past the plunger seal 23.
Referring to Figures 2 and 4, the rail section 18 is cruciform in transverse cross-section, including four rails 22, 24, 26 and 28. An elongate slot 30 is formed through at .least one of the rai.l.s (e.g., 22) in a region inwardly of the outer surface 32 thereof. As can be seen best in Figure 2, the outer surface 32 is substantially planar (but could also be a linear edge surface), and is free of notches and/or other stop member-retaining grooves. It is this feature which permits universal, infinite adjustment of the stop member on the plunger rod 14, within the finite distance of the elongate slot 30.
Referring to Figures l., 2 and 4, the axially adjustable stop member 1.6 is infinite.l.y variable along the length of the rail 22 on which it is mounted, and includes transversely spaced-apart legs 42 and 44 which straddle said rail. The lower end of the legs include inwardly directed, generally spherical projections 46 (Figure 4) which snap-fit into the elongate slot 30.
2~~ i~~~
-ll.-In this manner the stop member 7.6 is firmly retained for sliding movement on the rail 22. In addition, the cooperation between the slot 30 and spherical projections 46 permits pivotal movement of the stop member on the rail. to assist in locking the stop member 16 on a desired dose .line of a calibrated sc:al.e, in a manner which will. be described in greater detail hereinafter. However, at this point it should be noted that the recess between the t.ransversel.y spaced-apart legs 42 and 44 includes a base 52 which is spaced radial.ly outwardly of the outer surface 32 of rail 22 when the spherical. projections 46 .are retained within the elongate slot 30. Tt is this spacing that permits the pivotal movement between the stop member 1.6 and the rail 22 to take place.
Referring specifically to Figures 1 and 2, the slidable stop member 16 also includes a pair of transversely spaced-apart legs 54 and 56 at the trailing, or upstream, end thereof. These latter legs axe shorter in length than the legs 42 and 44, primarily because they do not need to cooperate with the elongate slot 30. However, these transversely spaced-apart legs 54 and 56 do cooperate with the transversely spaced-apart legs 42 and 44 to stabilize the stop member on the rail 22 so that it can be smoothly and easily slid along the rail.
-.12-Sti.l.l referring to Figures 1 and 2, the stop member .16 includes a cutting or knife edge 62 extending downwardly and rearward.ly .from a rear wall thereof far embedding into the outer surface 32 of the rail. This embedding action results in the effective locking of the stop member in any desired position on the rail, within the axial confines of the slot .30. That is, the stop member 16 can be axial.l.y moved along the entire length of the elongate slot 30 and be locked in any position along its length of travel by causing the cutting edge 62 thereof to embed into the outer edge surface 32 of the rail 22.
Referring specifically to Figures .1-.3, the stop member 16 preferably includes a generally concave groove or surface 63 in the upper surface thereof which can be engaged by a user's thumb or finger to slide the stop member to a desired position on the rail section 18 for the purpose of setting the dosage which is to be administered from the syringe 7Ø To accomplish this result a volumetric sc ale 64 is provided on a rail 28 of the plunger rod 14 which is adjacent and at right angles to the rail upon which the stop member 16 is mounted. An indicator line 66 is provided on each of the transversely spaced-apart legs 42 and 44 of the stop member 16 for the purpose of permitting the setting of the stop member on the p.ropeY dose line of -.13-the volumetric scale to dispense a desired volume of material from the syringe.
After the stop member 16 teas been slid to the desired position on the rail, the rear or upstream end of the stop member can be manua.l.ly pressed downwardl.y, in the direction indicated by arrow 67 in Figure 2, to force the cutting edge 62 to embed into the upper surface of the rail. This action locks the stop member in proper position on the r ail section 18 of the ~,lunger rod 14.
After the stop member 16 has been set to permit the syringe to dispense a desired dosage, as is illustrated in Figures 1 and 2, the thumb pad of plunger 14 is pressed axially inwardly in a downstream direction, as is indicated by arrow 68 in Figure 3, to dispense the desired volume of material.
Referring specifically to Figures 2 and 3, the stop member 16 includes a generally planar wall 70 at the downstream end thereof for engaging the generally planar surface 7.1 of the annular flange 72 located at the open upstream end of the syringe barrel 12 when the plunger rod 14 has been moved the precise distance for dispensing the desired volume of material from the syringe. In view of the fact that the wall 70 of the stop member 16 engages planar surface 71 of the syringe barrel 12 in a region radially outwardly of the pivot r . i ~, ;f.
axis for the stop member .16, the force imposed upon the stop member by this engagement will cause the stop member to rotate in the general direction indicated by arrow 74. This rotational movement causes the upstream or rear end of the stop member to move downwardly in the general direction of arrow 75 to enhance the locking action provided by the cutting edge 62 embedding into the outer surface 32 of the rail 22. In other words, the force imposed upon the stop member 16 at a point in time when the desired volume of material has been dispensed is in a direction to compliment the locking action between the stop member 16 and the rail section 18 of the plunger rod 14. This is an extremely important and desirable feature in the present invention since it prevents the inadvertent unlocking of the stop member from the rail section 18 which, if permitted to occur, could result in the dispensing of an undesired dosage from the syringe.
When it is desired to reset the stop member 16 after its first use for the purpose of dispensing a second desired dosage, the plunger 14 is first pulled outwardly to disengage the planar wall 70 of the stop member from the generally planar surface 71 of the annular flange 72. The resulting clearance is required to permit the stop member 16 to be rotated for the
4 ~ ; ,~3 ~ s t ~ ~-purpose of disengaging the cutting edge 62 from the rail 22.
Referring to Figures 5-7, an alternative embodiment of the syringe is generally shown at 80.
This syringe is virtually identic al to the syringe 10 discussed above, except for the construction of the axially moveable stop member 82, and the fact that the elongate slot .30 for cooperating with the stop member 16 in the syringe 7.0 is not required for cooperating i0 with the stop member 82 employed in the syringe 80.
still referring to Figures 5-7, the stop member 82 is a resilient clip member having a generally Ll-shaped barrel section 83 with the marginal ends 84 thereof defining slots 86 facing inwardly far receiving the marginal ends of diametrically opposed rails (e.g., 24 and 28) therein.
The stop member 82 has a smaller linear dimension than the stop member 16 employed in the earlier described embodiment of the invention. This shorter linear dimension permits the stop member 82 to be used with a standard length plunger. The greater linear dimension of the stop member 16 may require the plunger employed with the syringe to be of a custom size.
The clip member 82 further includes integrally molded knife edges 90 within the slots 86. Moreover, the clip member is molded so that the marginal ends 84 are normally biased inwardly toward each other to cause -.16-the knife edges 90 to embed in the outer marginal surfaces 32 of the arms 24 and 28, as can be seen best in Figure 7. As a result. of this arrangement the stop member 82 is automatically .locked to the rail section 18 of the plunger rod 14 to thereby prevent linear movement of the stop member along the p.l.unger rod.
Still referring to Figure 7, a vo.l.umetric scale 64 is provided on a planar surface of the rail 28 in the same manner as described earlier in connection with the 7.0 syringe 10. However, in the syringe 80 either the upstream or downstream marginal wa.l.l of the r.7.ip member 82 constitutes the indicator surface which is to be aligned with the desired volume indicator line of the volumetric scale 64.
Referring specifica.l.ly to Figure 6, the clip member 82 further includes inwardly directed ribs or arms 100, 102 at the base of the U-shaped barrel section 83 thereof, to thereby straddle and slidably engage the rail 22 of the rail section 1.8. The clip member 82 further includes outward.l.y directed actuating arms 104 which, when biased in an inward direction as indicated by the arrows 106, force the marginal ends 84 of the clip member outwardly, in the direction of arrow 7.08, to thereby re.l.ease the embedded engagement between ~5 knife edges 90 and the outer surfaces 32 of the rails 24 and 28. This permits the clip member 82 to be slid . .
along the rail section .18 to any desired position for controlling the volume of material to be dispensed from the syringe. Alternative.l.y, if desired, the actuating arms 104 can be sufficiently biased to actually permit the clip member 82 to be physically removed from the rail section 1.8, and thereafter re.lacated in a different area of the rod far the purpose of resetting the dosage to be dispensed or lacking the plunger against movement in a direction inter the syringe barrel. This permits the rapid setting of the stop member 82, in the same manner as the stop member .16, far either partia.ll.y err tata.l.ly emptying the syringe.
Another very important benefit of the alternative embodiment 80, like the embodiment 16, is that the stop member 82 can be attached to the plunger rod 14 after the syringe barrel .12 has been filled and the plunger rod inserted therein. This permits the economy of molding an all one-piece plunger and rod and a.l.lowing far the insta.l.lation of same after fil..ling the syringe, thus not interfering with automatic equipment handling of the product.
There are a variety of modifications which can be made to the syringes 10 and 80 within the scope of this invention. For example, although indicator lines 66 preferably are provided on both of the legs 42 and 44 of the stop member .16, it is within the scope of this -.18-invention to include the indicator line on only one leg, or alternatively, to employ one of the exposed marginal surfaces of the stop member as an indicator surface to be aligned with the volumetric sc ale 64.
Also, the specif is location of the va7.umetric scale on the rail section 18 may be varied. The important criteria is that an indicator line ar surface of the stag member be alignable with the dose lines on the volumetric scale to thereby set the desired dosage to be dispensed.
In connection with the syringe 80 the preferred clip member 82 includes a pair of axia.l.ly spaced-apart knife edges 90 associated with each of the slats 86 (Figure 7). However, if desired, the number and arrangement of these cutting edges may be varied.
One of the important aspects of this invention is that the stop members 16 and 82 are provided with cutting edges far embedding into a surface of a rail of the plunger rod .14. To this end, the stop members preferably are molded from a harder plastic material than that which is employed to fabricate the rail section 18 o.f the plunger rod 14. For example, the stop members 16 and 82 can be mo7.ded of a hard plastic, such as nylon ar deldrin, whereas the rail section 18 of the plunger rod 14 can be molded of a softer polymer, such as high or low density polyethylene. The -l.9-specific plastics employed to fabricate the syringes 10 and 80 are not considered limitations on the present invention. However, in accordance with a preferred embodiment of the invention, the important factor is that the plastic material. employed t.o form the stop members 7.6 and 82 be harder than the plastic material employed to form the rail. section ).8 in the syringes 10 and 80. If desired, the knife edge may be provided on a separate metal member, in which case the plastic employed to farm the rail section 18 need on7.y be soft enough to permit the metal. knife edge to embed therein.
Without further elaboration, the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, adopt. the same for use under various conditions of service.
Referring to Figures 5-7, an alternative embodiment of the syringe is generally shown at 80.
This syringe is virtually identic al to the syringe 10 discussed above, except for the construction of the axially moveable stop member 82, and the fact that the elongate slot .30 for cooperating with the stop member 16 in the syringe 7.0 is not required for cooperating i0 with the stop member 82 employed in the syringe 80.
still referring to Figures 5-7, the stop member 82 is a resilient clip member having a generally Ll-shaped barrel section 83 with the marginal ends 84 thereof defining slots 86 facing inwardly far receiving the marginal ends of diametrically opposed rails (e.g., 24 and 28) therein.
The stop member 82 has a smaller linear dimension than the stop member 16 employed in the earlier described embodiment of the invention. This shorter linear dimension permits the stop member 82 to be used with a standard length plunger. The greater linear dimension of the stop member 16 may require the plunger employed with the syringe to be of a custom size.
The clip member 82 further includes integrally molded knife edges 90 within the slots 86. Moreover, the clip member is molded so that the marginal ends 84 are normally biased inwardly toward each other to cause -.16-the knife edges 90 to embed in the outer marginal surfaces 32 of the arms 24 and 28, as can be seen best in Figure 7. As a result. of this arrangement the stop member 82 is automatically .locked to the rail section 18 of the plunger rod 14 to thereby prevent linear movement of the stop member along the p.l.unger rod.
Still referring to Figure 7, a vo.l.umetric scale 64 is provided on a planar surface of the rail 28 in the same manner as described earlier in connection with the 7.0 syringe 10. However, in the syringe 80 either the upstream or downstream marginal wa.l.l of the r.7.ip member 82 constitutes the indicator surface which is to be aligned with the desired volume indicator line of the volumetric scale 64.
Referring specifica.l.ly to Figure 6, the clip member 82 further includes inwardly directed ribs or arms 100, 102 at the base of the U-shaped barrel section 83 thereof, to thereby straddle and slidably engage the rail 22 of the rail section 1.8. The clip member 82 further includes outward.l.y directed actuating arms 104 which, when biased in an inward direction as indicated by the arrows 106, force the marginal ends 84 of the clip member outwardly, in the direction of arrow 7.08, to thereby re.l.ease the embedded engagement between ~5 knife edges 90 and the outer surfaces 32 of the rails 24 and 28. This permits the clip member 82 to be slid . .
along the rail section .18 to any desired position for controlling the volume of material to be dispensed from the syringe. Alternative.l.y, if desired, the actuating arms 104 can be sufficiently biased to actually permit the clip member 82 to be physically removed from the rail section 1.8, and thereafter re.lacated in a different area of the rod far the purpose of resetting the dosage to be dispensed or lacking the plunger against movement in a direction inter the syringe barrel. This permits the rapid setting of the stop member 82, in the same manner as the stop member .16, far either partia.ll.y err tata.l.ly emptying the syringe.
Another very important benefit of the alternative embodiment 80, like the embodiment 16, is that the stop member 82 can be attached to the plunger rod 14 after the syringe barrel .12 has been filled and the plunger rod inserted therein. This permits the economy of molding an all one-piece plunger and rod and a.l.lowing far the insta.l.lation of same after fil..ling the syringe, thus not interfering with automatic equipment handling of the product.
There are a variety of modifications which can be made to the syringes 10 and 80 within the scope of this invention. For example, although indicator lines 66 preferably are provided on both of the legs 42 and 44 of the stop member .16, it is within the scope of this -.18-invention to include the indicator line on only one leg, or alternatively, to employ one of the exposed marginal surfaces of the stop member as an indicator surface to be aligned with the volumetric sc ale 64.
Also, the specif is location of the va7.umetric scale on the rail section 18 may be varied. The important criteria is that an indicator line ar surface of the stag member be alignable with the dose lines on the volumetric scale to thereby set the desired dosage to be dispensed.
In connection with the syringe 80 the preferred clip member 82 includes a pair of axia.l.ly spaced-apart knife edges 90 associated with each of the slats 86 (Figure 7). However, if desired, the number and arrangement of these cutting edges may be varied.
One of the important aspects of this invention is that the stop members 16 and 82 are provided with cutting edges far embedding into a surface of a rail of the plunger rod .14. To this end, the stop members preferably are molded from a harder plastic material than that which is employed to fabricate the rail section 18 o.f the plunger rod 14. For example, the stop members 16 and 82 can be mo7.ded of a hard plastic, such as nylon ar deldrin, whereas the rail section 18 of the plunger rod 14 can be molded of a softer polymer, such as high or low density polyethylene. The -l.9-specific plastics employed to fabricate the syringes 10 and 80 are not considered limitations on the present invention. However, in accordance with a preferred embodiment of the invention, the important factor is that the plastic material. employed t.o form the stop members 7.6 and 82 be harder than the plastic material employed to form the rail. section ).8 in the syringes 10 and 80. If desired, the knife edge may be provided on a separate metal member, in which case the plastic employed to farm the rail section 18 need on7.y be soft enough to permit the metal. knife edge to embed therein.
Without further elaboration, the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, adopt. the same for use under various conditions of service.
Claims (22)
1. A syringe for dispensing a predetermined dosage of material, the syringe comprising:
a hollow barrel having a discharge end from which the material can be dispensed and an open, opposite end;
a plunger rod slidably received in said barrel through said open opposite end, said plunger rod including a rail section having at least a portion thereof located outside of said barrel, said plunger rod being movable in a downstream direction into said barrel for dispensing the material; and a stop mounted for movement along the length of said rail section engageable by said barrel to establish the length of travel of said plunger rod in said downstream direction for controlling the volume of material to be dispensed, said stop being selectively fixedly-engageable with said rail section at any one of an infinite number of desired positions to lock said stop in a desired position on said rail section;
said stop including a knife edge selectively movable between a first position disengaged from said rail section and a second position embedded into said rail section at a precise desired location therealong;
said stop further including a downstream surface for engaging a surface of the syringe barrel at the open end of said barrel when the plunger rod has been moved in a downstream direction to dispense a desired volume of material;
wherein the stop is pivotally secured to the plunger rod, whereby engagement of the downstream surface of the stop with the surface of the syringe barrel at the open end of said barrel forces the stop to pivot in a direction for aiding in embedding the knife edge of the stop into the rail section of the plunger rod.
a hollow barrel having a discharge end from which the material can be dispensed and an open, opposite end;
a plunger rod slidably received in said barrel through said open opposite end, said plunger rod including a rail section having at least a portion thereof located outside of said barrel, said plunger rod being movable in a downstream direction into said barrel for dispensing the material; and a stop mounted for movement along the length of said rail section engageable by said barrel to establish the length of travel of said plunger rod in said downstream direction for controlling the volume of material to be dispensed, said stop being selectively fixedly-engageable with said rail section at any one of an infinite number of desired positions to lock said stop in a desired position on said rail section;
said stop including a knife edge selectively movable between a first position disengaged from said rail section and a second position embedded into said rail section at a precise desired location therealong;
said stop further including a downstream surface for engaging a surface of the syringe barrel at the open end of said barrel when the plunger rod has been moved in a downstream direction to dispense a desired volume of material;
wherein the stop is pivotally secured to the plunger rod, whereby engagement of the downstream surface of the stop with the surface of the syringe barrel at the open end of said barrel forces the stop to pivot in a direction for aiding in embedding the knife edge of the stop into the rail section of the plunger rod.
2. A syringe as set forth in claim 1, wherein the rail section includes at least one rail, said stop being slidably and pivotally attached to the rail for permitting both linear movement of the stop along said rail and pivotal movement of the stop relative to said rail for aiding in embedding the knife edge of the stop into a surface of said rail, said rail including an elongated opening therein, and said stop including legs having projections for engaging said elongated opening, whereby said stop is linearly movable within the confines of said elongated opening and is pivotally secured to said rail within said opening by said projections.
3. A syringe as set forth in claim 1 or 2, wherein both the rail section of the plunger rod and the stop are made from plastics materials, the plastics material of the rail section being softer than the plastics material of the stop.
4. A syringe as set forth in claim 1, 2 or 3, wherein indicia means are included on said rail section for indicating a volume of the material to be dispensed at each selected location at which said stop is fixedly engaged with said rail section.
5. A syringe as set forth in claim 4, wherein the rail section is cruciform in cross-section and includes four rails, each rail being disposed at an angle of ninety degrees from each adjacent rail, said stop being slidable on one of said rails and said indicia means being included on a rail adjacent the rail on which the stop is slidable.
6. A syringe as set forth in any one of claims 1 to 5, wherein said stop is a resilient clip having spaced-apart marginal edges therein for defining slots facing inwardly and receiving sections of the rail section therein, said slots including knife edges therein for embedding in sections of the rail section received within the slots.
7. A syringe as set forth in claim 6, wherein the spaced-apart marginal edges are normally biased toward each other to move the knife edges into embedded engagement with the rail section to thereby lock the clip member to the rail section for preventing axial movement of the clip member relative to the rail section.
8. A syringe as set forth in claim 6 or 7, wherein said rail section is cruciform in cross-section and includes four rails, each rail being disposed at an angle of ninety degrees from each adjacent rail, said slots being diametrically opposed to each other for receiving rails which are diametrically opposed to each other, said knife edges being located at the bases of the slots for embedding in outer exposed surfaces of said diametrically opposed rails.
9. A syringe for dispensing a predetermined dosage of material, the syringe comprising:
a hollow syringe barrel having a discharge end for the material to be dispensed and an open, opposite end;
a plunger rod slidably received in said syringe barrel through said open, opposite end, said plunger rod having a first end portion located within said syringe barrel and a rail section having at least a portion thereof located outside of said syringe barrel, said plunger rod being movable in a downstream direction into said syringe barrel for dispensing a material through the discharge end of said syringe barrel ; and a stop member hingedly mounted on the rail section in a region outside of said syringe barrel and being axially movable along the length of the rail section to set the length of travel of the plunger rod in said downstream direction for controlling the volume of material to be dispensed, the stop member including a knife edge, and said stop member, when pivoted in a direction opposite the downstream direction, embedding the knife edge into the rail section to lock the stop member in any one of an infinite number of desired positions on said rail section.
a hollow syringe barrel having a discharge end for the material to be dispensed and an open, opposite end;
a plunger rod slidably received in said syringe barrel through said open, opposite end, said plunger rod having a first end portion located within said syringe barrel and a rail section having at least a portion thereof located outside of said syringe barrel, said plunger rod being movable in a downstream direction into said syringe barrel for dispensing a material through the discharge end of said syringe barrel ; and a stop member hingedly mounted on the rail section in a region outside of said syringe barrel and being axially movable along the length of the rail section to set the length of travel of the plunger rod in said downstream direction for controlling the volume of material to be dispensed, the stop member including a knife edge, and said stop member, when pivoted in a direction opposite the downstream direction, embedding the knife edge into the rail section to lock the stop member in any one of an infinite number of desired positions on said rail section.
10. The syringe of claim 9, wherein both the rail section of the plunger rod and the stop member are made from plastics materials, the plastics material of the rail section being softer than the plastics material of the stop member.
11. The syringe of claim 10 or 11, wherein the stop member includes a downstream surface for engaging a surface of the syringe barrel at the open end of said barrel when the plunger rod has been moved in a downstream direction to dispense a desired volume of material, said knife edge being located at an upstream end of the stop member, whereby engagement of the downstream surface of the stop member with the surface of the syringe barrel at the open end of said barrel forces the stop member to pivot in a direction for causing the knife edge to embed into the rail section of the plunger rod.
12. The syringe of claim 9, 10 or 11, wherein the rail section includes at least one rail, said stop member being slidably and pivotally attached to a rail for permitting linear movement of the stop member along said rail, and pivotal movement of the stop member relative to said rail for aiding in embedding the knife edge of the stop member into a surface of said rail.
13. The syringe of claim 12, wherein the rail includes an elongated opening therein, said stop member including leg means for straddling said rail, and projection means on said leg means for engaging within said elongated opening, whereby said stop member is linearly movable within the confines of said elongated opening and is pivotally secured to said rail within said opening by said projection means.
14. The syringe of claim 13, wherein the stop member includes a downstream surface for engaging a surface of the syringe barrel at the open end of said syringe barrel when the plunger rod has been moved in a downstream direction to dispense a desired volume of material, said knife edge being located at an upstream end of the stop member, whereby engagement of the downstream surface of the stop member with the surface of the syringe barrel at the open end of said barrel forces the stop member to pivot in a direction for causing the knife edge to embed into the rail section of the plunger rod.
15. The syringe of any one of claims 9 to 14, wherein said rail section includes a volumetric scale thereon and said stop member includes an indicator means for cooperating with the volumetric scale for permitting the stop member to be locked on the rail section in a location for dispensing a desired volume of material.
16. The syringe of claim 15, wherein the rail section is cruciform in cross-section and includes four rails, each rail being disposed at an angle of ninety degrees from each adjacent rail, said stop member being slidable on one of said rails and said volumetric scale being included on a rail adjacent the rail on which the stop member is slidable.
17. The syringe of any one of claims 9 to 16, wherein the stop member is both slidable and pivotal on the rail.
18. A syringe for dispensing a predetermined dosage of material, the syringe, comprising:
a hollow syringe barrel having a discharge end for the material to be dispensed and an open, opposite end;
a plunger rod slidably received in said syringe barrel through said open, opposite end, said plunger rod having a first end portion located within said syringe barrel and a rail section having at least a portion thereof located outside of said syringe barrel, said plunger being movable in a downstream direction into said syringe barrel for dispensing a material through the discharge of said syringe barrel; and a stop member hingedly mounted on the rail section in a region outside of said syringe barrel and being axially movable along the length of the rail section to set the length of travel of the plunger rod in said downstream direction for controlling the volume of material to be dispensed, the stop member comprising a resilient clip having spaced-apart marginal ends with slots therein for receiving sections of the rail section therein, said ends including knife edges therein for embedding in sections of the rail section received within the slots to lock the stop member in any one of an infinite number of desired positions on said rail section.
a hollow syringe barrel having a discharge end for the material to be dispensed and an open, opposite end;
a plunger rod slidably received in said syringe barrel through said open, opposite end, said plunger rod having a first end portion located within said syringe barrel and a rail section having at least a portion thereof located outside of said syringe barrel, said plunger being movable in a downstream direction into said syringe barrel for dispensing a material through the discharge of said syringe barrel; and a stop member hingedly mounted on the rail section in a region outside of said syringe barrel and being axially movable along the length of the rail section to set the length of travel of the plunger rod in said downstream direction for controlling the volume of material to be dispensed, the stop member comprising a resilient clip having spaced-apart marginal ends with slots therein for receiving sections of the rail section therein, said ends including knife edges therein for embedding in sections of the rail section received within the slots to lock the stop member in any one of an infinite number of desired positions on said rail section.
19. The syringe of claim 18, wherein said rail section is cruciform in cross-section and includes four rails, each rail being disposed at an angle of ninety degrees from each adjacent rail, said slots being diametrically opposed to each other for receiving rails which are diametrically opposed to each other, said knife edges being located at the bases of the slots for embedding in outer exposed surfaces of said diametrically opposed rails.
20. The syringe of claim 19, wherein a pair of knife edges are located at the base of each slot, said knife edges in each slot being spaced-apart from each other in the axial direction of movement of the plunger rod.
21. The syringe of claim 18, 19 or 20, wherein the spaced-apart marginal ends are normally biased toward each other to move the knife edges into embedded engagement with the rail section, to thereby lock the clip to the rail section for preventing axial movement of the clip relative to the rail section.
22. The syringe of any one of claims 18 to 21, wherein said resilient clip includes actuating arm means for biasing the spaced-apart marginal ends away from each other to move the knife edges out of embedded engagement with the rail section, to thereby permit the resilient clip member to be moved relative to the rail section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2036940 CA2036940C (en) | 1991-02-22 | 1991-02-22 | A syringe for dispensing measured quantities of a medicament |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2036940 CA2036940C (en) | 1991-02-22 | 1991-02-22 | A syringe for dispensing measured quantities of a medicament |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2036940A1 CA2036940A1 (en) | 1992-08-23 |
| CA2036940C true CA2036940C (en) | 2002-01-29 |
Family
ID=4147047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2036940 Expired - Lifetime CA2036940C (en) | 1991-02-22 | 1991-02-22 | A syringe for dispensing measured quantities of a medicament |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2036940C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102753275B (en) | 2010-02-12 | 2015-05-13 | 药物混合系统股份公司 | Discharge device having a locking element |
| CN113995865A (en) * | 2020-10-14 | 2022-02-01 | 苏州曦龙净化设备有限公司 | Disinfection medicine equipment |
-
1991
- 1991-02-22 CA CA 2036940 patent/CA2036940C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2036940A1 (en) | 1992-08-23 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKEX | Expiry |