Syringe retractable needle and method
First Claim
1. A syringe with retractable needle comprising, in combination, a syringe having a barrel which is essentially cylindrical and longitudinal in configuration;
- a piston which is hollow and configured for movable mounting interiorly of the barrel of the syringe;
a needle assembly;
a piston seal provided at the end of the closest to the needle assembly;
means for securing the piston seal to the syringe barrel immovably resisting any effort of the piston seal to slide longitudinally along the piston in operation;
a plug removably secured at the end of the piston closest the needle assembly which is proportioned to fit within the piston to be removably propelled when contacting the needle assembly;
said needle assembly including a spring coaxially mounted surrounding a needle, which spring is positioned to press underneath the head of the needle in biased relationship with the end of the barrel to thereby dislodge the needle assembly;
a chuck seal for securely positioning interiorly of the end of the barrel and in surrounding relationship to the needle head;
said needle head and said chuck seal being proportioned to have a resiliently secured interface attributable to the dimensioning of the chuck seal and relating it to the needle head;
said chuck seal having a chuck seal ramp at the end facing the piston plug; and
a chuck seal annular key at the seal end of the piston proportioned to engage the chuck seal ramp to release the chuck seal from the needle head;
all such elements being formed and proportioned to permit the piston, after the barrel is filled to the preselected quantity of injectant, to be moved forwardly and then substantially simultaneously at the end of the stroke of the piston dislodge the piston plug and then have the chuck seal key open the chuck seal ramp, and then spring propelledly permitting the needle assembly to be sent into the interior portion of the piston.
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Accused Products
Abstract
A syringe carrying a needle with a barrel and hollow piston for dispersing an injectant through the end of the retractable needle. A resilient chuck seal is independently formed for positioning at the transition from the syringe barrel to the needle shank holding portion of the end of the barrel. The needle is propelled by the coaxial spring into the interior portion of the piston and totally retracted when the chuck seal is released. The method of the present invention relates to the use of a symmetrical chuck seal, annular in configuration, for not only gripping the head of the retractable needle, but simultaneously serving as the seal for the needle at the lower portion of the barrel so that the injectant escapes through the hollow syringe needle.
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Citations
29 Claims
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1. A syringe with retractable needle comprising, in combination,
a syringe having a barrel which is essentially cylindrical and longitudinal in configuration; -
a piston which is hollow and configured for movable mounting interiorly of the barrel of the syringe;
a needle assembly;
a piston seal provided at the end of the closest to the needle assembly;
means for securing the piston seal to the syringe barrel immovably resisting any effort of the piston seal to slide longitudinally along the piston in operation;
a plug removably secured at the end of the piston closest the needle assembly which is proportioned to fit within the piston to be removably propelled when contacting the needle assembly;
said needle assembly including a spring coaxially mounted surrounding a needle, which spring is positioned to press underneath the head of the needle in biased relationship with the end of the barrel to thereby dislodge the needle assembly;
a chuck seal for securely positioning interiorly of the end of the barrel and in surrounding relationship to the needle head;
said needle head and said chuck seal being proportioned to have a resiliently secured interface attributable to the dimensioning of the chuck seal and relating it to the needle head;
said chuck seal having a chuck seal ramp at the end facing the piston plug; and
a chuck seal annular key at the seal end of the piston proportioned to engage the chuck seal ramp to release the chuck seal from the needle head;
all such elements being formed and proportioned to permit the piston, after the barrel is filled to the preselected quantity of injectant, to be moved forwardly and then substantially simultaneously at the end of the stroke of the piston dislodge the piston plug and then have the chuck seal key open the chuck seal ramp, and then spring propelledly permitting the needle assembly to be sent into the interior portion of the piston. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of forming a syringe with retractable needle comprising the steps of:
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providing a syringe with a hollow barrel;
providing a coaxial hollow piston interiorly of the hollow barrel, a seal at one end of the hollow piston for biasing the end of the piston against the interior portion of the barrel and thereby sealing it;
adding a cap to the piston for engagement by the user and positioning a needle assembly with a coaxial spring which is secured against the needle assembly head in the end of the barrel;
the improved method of inserting a permanently fixed chuck seal at the injecting end of the barrel which chuck seal has an expandable interior in compressive relationship with the head of the needle and which is proportioned along with the positioning of the piston to substantially simultaneously dislodge the piston end plug at the same time the chuck seal is engaged by an annular key at the end of the piston which opens the chuck seal and permits the retractable needle to be propelled into place interiorly of the hollow piston.
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11. In a syringe including a barrel, a hollow piston mounted coaxially in the barrel, a piston seal, a piston plug, and a piston cap with the piston seal located in a groove at the opposite end of the piston from the piston cap, and the piston plug positioned at the end of the piston adjacent the piston seal and removably secured therein for shifting interiorly of the barrel, said piston being secured coaxially and interiorly of said barrel, a chuck seal key at the end of the piston closest to the needle head, a barrel nose at the end of the barrel opposite the cap, a needle assembly secured interiorly of the barrel nose, said needle assembly including a shank, needle head at one end, a needle secured within the needle shank with its discharged portion removed from a needle head, a spring comprehensibly biasing the needle to be moved into the hollow piston, the improvement comprising:
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an annular elastomeric symmetrical chuck seal having an outer diameter, an inner diameter, a body, and a chuck seal ramp at one end commencing at the inner diameter and progressing angularly radially outwardly from the inner diameter;
weakening means in said chuck seal to permit bending the seal when the ramp is engaged by the chuck key in one of said ramps spaced to define chuck seal jaws therebetween;
said chuck seal having a diameter to fit within a chuck seal groove at the end of the barrel nose to bridge and seal the space between the interior portion of the barrel nose and the needle head which, upon activation by spreading the jaws releases the needle head for yieldable propulsion into the interior portion of the. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. An elastomeric chuck seal for use in a syringe having a barrel and a barrel nose to receive a needle assembly and a piston in said barrel for removing and retaining a needle assembly having a head which is in spring loaded relationship to the syringe, said chuck seal comprising:
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an annular elastomeric member, cylindrical in nature, said member having an inner and an outer cylindrical surfaces;
a frusto conical ramp at one opening to the inner diameter;
said ramp inclining radially outwardly defining a frusto conical ramp surface;
a cylindrical annular undercut in the end of the seal opposite the ramp defining two coaxial skirts;
the chuck seal having a body formed and proportioned to fit within a chuck seal chamber at the nose portion of the barrel in surrounding and seating relationship to the needle assembly and having sufficient interference with the needle head to hold the same in place against a resilient load applied to the needle head and coaxially with the needle in the direction of the piston and said chuck seal is immovably secured coaxially along the needle head to thereby continually seal the needle during the entire period of injection and retraction of the needle head into the syringe body. - View Dependent Claims (19, 20, 21, 22, 23)
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24. An elastomeric chuck seal in a syringe for first retaining and thereafter removing a needle assembly having a head which is in spring loaded relationship to the syringe, said chuck seal comprising:
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an annular elastomeric member, cylindrical in nature, said cylinder having an inner an an outer cylindrical surfaces;
frusto conical ramp at one opening to the inner diameter;
said ramp inclining radially outwardly defining a frusto conical ramp surface;
the body of the chuck seal extending away from the chuck seal ramp having an annular groove to thereby define an outer skirt and an inner skirt in which the outer skirt particularly collapses in one inner skirt when the ramp is engaged and opened;
the chuck seal having a body formed and proportioned to fit within a chuck seal chamber at the nose portion of the barrel in surrounding and needle head to hold the same in place against a resilient load applied to the needle head and coaxially with the needle in the direction of the piston and said chuck seal is immovably secured coaxially along the needle head to thereby continually seal the needle during the entire period of injection and retraction of the needle head into the syringe body. - View Dependent Claims (25, 26, 27, 28, 29)
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Specification