Automatic injection devices
First Claim
Patent Images
1. An injection device, comprising:
- a housing;
a syringe coupled to a needle at one end, the syringe slideably mounted within the housing for movement between a first position relative to the housing in which the needle is shrouded by the housing and a second position relative to the housing in which the needle projects from the housing;
a bung slideably mounted in the syringe and moveable to expel a liquid through the needle;
a plunger comprising;
an upper solid portion,a lower solid portion having one end operable to move the bung and to transmit an expulsion force thereto, anda projecting region comprising one or more flexible elbows on either side of a central void provided between the upper and lower solid portions of the plunger, the plunger having a first length when the projecting region is in a projecting position in which the one or more elbows project outwardly from the central void, the plunger having a second length greater than the first length when the projecting region is in a collapsed position in which the one or more elbows are collapsed inwardly toward the central void; and
an actuating bias member provided at one end of the housing and operable to move the plunger toward another end of the housing.
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Accused Products
Abstract
An injection device comprises a syringe extendible against a spring bias from a retracted position in a housing to a projecting injecting position. A spring biased plunger has collapsible elbows which, when the plunger is released, initially engage the end of the syringe to drive it to the projecting position, whereupon arresting of the syringe movement causes the elbows to collapse inside the syringe to allow the plunger to engage and drive the bung.
404 Citations
19 Claims
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1. An injection device, comprising:
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a housing; a syringe coupled to a needle at one end, the syringe slideably mounted within the housing for movement between a first position relative to the housing in which the needle is shrouded by the housing and a second position relative to the housing in which the needle projects from the housing; a bung slideably mounted in the syringe and moveable to expel a liquid through the needle; a plunger comprising; an upper solid portion, a lower solid portion having one end operable to move the bung and to transmit an expulsion force thereto, and a projecting region comprising one or more flexible elbows on either side of a central void provided between the upper and lower solid portions of the plunger, the plunger having a first length when the projecting region is in a projecting position in which the one or more elbows project outwardly from the central void, the plunger having a second length greater than the first length when the projecting region is in a collapsed position in which the one or more elbows are collapsed inwardly toward the central void; and an actuating bias member provided at one end of the housing and operable to move the plunger toward another end of the housing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A syringe assembly, comprising:
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a syringe coupled to a needle at one end, the syringe slideably mounted within a housing for movement between a first position relative to the housing in which the needle is shrouded by the housing and a second position relative to the housing in which the needle projects from the housing; a bung slideably mounted in the syringe; and a plunger comprising; an upper solid portion, a lower solid portion having one end operable to move the bung and to transmit an expulsion force thereto, and a projecting region comprising one or more flexible elbows on either side of a central void provided between the upper and lower solid portions of the plunger, the plunger having a first length when the projecting region is in a projecting position in which the one or more elbows project outwardly from the central void, the plunger having a second length greater than the first length when the projecting region is in a collapsed position in which the one or more elbows are collapsed inwardly toward the central void. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method for operating an automatic injection device, the method comprising:
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operating an actuating bias member to move a plunger including a projecting region comprising an upper solid portion, a lower solid portion and one or more flexible elbows on either side of a central void provided between the upper and lower solid portions of the plunger, wherein the projecting region is in a projecting position when the one or more elbows project outwardly from the central void and in a collapsed position when the one or more elbows are collapsed inwardly toward the central void; and engaging one end of a syringe with the plunger to drive the syringe from a first position relative to a housing in which a needle coupled to another end of the syringe is shrouded by the housing to a second position relative to the housing in which the needle projects from the housing; wherein the projecting region of the plunger is in the projecting position prior to entering the syringe and wherein the projecting region is in the collapsed position inside the syringe for applying an expulsion force to a bung in the syringe in order to compress a liquid dose in the syringe and cause expression of the liquid dose from the syringe, wherein a collapsing movement of the projecting region toward the central void from the projecting position outside the syringe to the collapsed position inside the syringe causes an elongation in the length of the plunger. - View Dependent Claims (16, 17, 18, 19)
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Specification