Elastomeric plunger tip for a syringe

Claim 2

An elastomeric plunger tip particularly suited for a blood sampling syringe, said tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip if inserted in said syringe, said plunger tip providing the syringe with a self-aspirating characteristic when used to sample arterial blood while maintaining an effective seal for containing the blood sample.

Claim 3

An elastomeric plunger tip according to claim 1 wherein said material has a durometer of about 50 to 70 on the Shore A scale.

Claim 4

An elastomeric plunger tip according to claim 1 wherein said material is selected from the group consisting of natural rubber and its man-made equivalents, butyl rubbers and silicone rubbers.

Claim 5

An elastomeric plunger tip according to claim 1 wherein said material is natural gum rubber.

Claim 6

An elastomeric plunger tip according to claim 4 wherein said natural gum rubber has a durometer of about 63 on the Shore A scale.

Claim 7

An elastomeric plunger tip according to claim 1 wherein said material is butyl rubber.

Claim 8

An elastomeric plunger tip according to claim 1 wherein said material has the ability to retain its resilience at temperatures of about -40° C.

Claim 9

A compressible and elastomeric syringe plunger tip particularly suited for a blood sampling syringe comprising a generally cylindrical main portion, an integral annular elastically deformable wiper extending peripherally radially outwardly and axially forwardly from a forward portion thereof at an acute angle to the longitudinal center axis of said tip and terminating at the outer edge thereof in a wiping edge, when used in a syringe assembly said annular wiper being the sole sealing element between said plunger tip and the syringe, said tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said plunger tip providing the syringe with a self-aspirating characteristic when used to sample arterial blood while maintaining an effective seal for containing the blood sample.

Claim 10

A compressible and elastomeric syringe plunger tip particularly suited for a blood sampling syringe comprising a generally cylindrical main portion, an integral annular elastically deformable wiper extending peripherally radially outwardly and axially forwardly from a forward portion thereof at an acute angle to the longitudinal center axis of said tip and terminating at the outer edge thereof in a wiping edge, when used in a syringe assembly said annular wiper being the sole sealing element between said plunger tip and the syringe, said tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said plunger tip providing the syringe with a self-aspirating characteristic when used to sample arterial blood while maintaining an effective seal for containing the blood sample.

Claim 11

A tip according to claim 8, said main portion having an end portion of reduced diameter.

Claim 12

A tip according to claim 9, said wiper and reduced diameter portion forming an annular trough in the forward face of said tip.

Claim 13

A tip according to claim 8, the edge of said wiper comprising a generally cylindrically shaped surface which extends radially outwardly and axially forwardly at a straight acute angle to the longitudinal center line of said tip.

Claim 14

A tip according to claim 11, the thickness of said wiper being tapered from the base thereof to the free end thereof so it is thicker at its base than at its end.

Claim 15

An elastomeric plunger tip according to claim 8 wherein said material has a durometer of about 50 to 70 on the Shore A scale.

Claim 16

An elastomeric plunger tip according to claim 8 wherein said material is selected from the group consisting of natural rubber and its man-made equivalents, butyl rubbers and silicone rubbers.

Claim 17

An elastomeric plunger tip according to claim 8 wherein said material is natural gum rubber.

Claim 18

An elastomeric plunger tip according to claim 15 wherein said natural gum rubber has a durometer of about 63 on the Shore A scale.

Claim 19

An elastomeric plunger tip according to claim 8 wherein said material is silicone rubber.

Claim 20

An elastomeric plunger tip according to claim 8 wherein said material has the ability to retain its resilience at temperatures of about -40° C.

Claim 21

A tip according to claim 8, the thickness of said wiper being tapered from the base thereof to the free end thereof so that it is thicker at its base than at its end.

Claim 22

A syringe assembly according to claim 19, wherein the angle between the leading surface of said wiper and the longitudinal axis is between about 30° and 50° and the angle of the taper is between about 10° and 15°.

Claim 23

A syringe assembly according to claim 8, said wiping edge comprising a plane surface of minor dimension oriented substantially parallel to the longitudinal axis of said plunger tip.

Claim 24

A syringe assembly according to claim 21 wherein said plane surface extends radially outwardly and axially forwardly at a very slight angle.

Claim 25

A syringe assembly according to claim 22 wherein the angle is about 2°.

Claim 26

A compressible and elastomeric syringe plunger tip comprising a generally cylindrical main portion, an integral annular elastically deformable wiper extending peripherally radially outwardly and axially forwardly from a forward portion thereof at an acute angle to the longitudinal center axis of said tip and terminating at the outer edge thereof in a wiping edge, when used in a syringe assembly said annular wiper being the sole sealing element between said plunger tip and the syringe, said tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said plunger tip having a plurality of raised portions speed circumferentially around said plunger tip and located at the rearward portion of said plunger tip, said raised portions engaging the wall of said syringe, when the plunger tip is inserted therein, to prevent canting of said plunger tip.

Claim 27

A compressible and elastomeric syringe plunger tip comprising a generally cylindrical main portion, an integral annular elastically deformable wiper extending peripherally radially outwardly and axially forwardly from a forward portion thereof at an acute angle to the longitudinal center axis of said tip and terminating at the outer edge thereof in a wiping edge, when used in a syringe assembly said annular wiper being the sole sealing element between said plunger tip and the syringe, said tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said plunger tip having a plurality of raised portions speed circumferentially around said plunger tip and located at the rearward portion of said plunger tip, said raised portions engaging the wall of said syringe, when the plunger tip is inserted therein, to prevent canting of said plunger tip.

Claim 28

An elastomeric plunger tip according to claim 24 wherein said material has a durometer of about 50 to 70 on the Shore A scale.

Claim 29

An elastomeric plunger tip according to claim 24 wherein said material is selected from the group consisting of natural rubber and its man-made equivalents, butyl rubbers and silicone rubbers.

Claim 30

An elastomeric plunger tip according to claim 24 wherein said material is natural gum rubber.

Claim 31

An elastomeric plunger tip according to claim 27 wherein said natural gum rubber has a durometer of about 63 on the Shore A scale.

Claim 32

A self-aspirating disposable syringe assembly particularly suited because of the low force requirement for the operation thereof to be used for obtaining a blood sample from a patient comprising a barrel having a cylindrical inner wall and a plunger comprising a plunger stem and a compressible, elastomeric, generally cylindrical plunger tip of lesser diameter than the inner wall of said barrel, said plunger tip having an integral, annular, elastically deformable wiper extending peripherally radially outwardly and axially forwardly from said plunger tip at a forward portion thereof at an acute angle to the longitudinal center axis of said plunger tip and terminating at the other edge thereof in a wiping edge thereof in a wiping edge having a minimal diameter slightly in excess of the diameter of the inner wall of said barrel, thereby forming a sealing engagement with the inner wall of said barrel, said annular wiper being the sole sealing element between said plunger tip and said wall, said plunger tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said plunger tip providing the syringe with a self-aspirating characteristic when used to sample arterial blood while maintaining an effective seal for containing the blood sample.

Claim 33

A self-aspirating disposable syringe assembly particularly suited because of the low force requirement for the operation thereof to be used for obtaining a blood sample from a patient comprising a barrel having a cylindrical inner wall and a plunger comprising a plunger stem and a compressible, elastomeric, generally cylindrical plunger tip of lesser diameter than the inner wall of said barrel, said plunger tip having an integral, annular, elastically deformable wiper extending peripherally radially outwardly and axially forwardly from said plunger tip at a forward portion thereof at an acute angle to the longitudinal center axis of said plunger tip and terminating at the other edge thereof in a wiping edge thereof in a wiping edge having a minimal diameter slightly in excess of the diameter of the inner wall of said barrel, thereby forming a sealing engagement with the inner wall of said barrel, said annular wiper being the sole sealing element between said plunger tip and said wall, said plunger tip comprising a compressible, elastomeric material having a durometer of about 35 to about 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said plunger tip providing the syringe with a self-aspirating characteristic when used to sample arterial blood while maintaining an effective seal for containing the blood sample.

Claim 34

A syringe assembly according to claim 29, said wiper being tapered from the base thereof to the free end thereof so that it is thicker at its base than at its end.

Claim 35

A syringe assembly according to claim 30, wherein the angle between the leading surface of said wiper and the longitudinal axis is between about 30° and 50° and the angle of the taper is between about 10° and 15°.

Claim 36

A disposable syringe assembly according to claim 29 wherein said material has a durometer of about 50 to 70 on the Shore A scale.

Claim 37

A disposable syringe assembly according to claim 29 wherein said material is selected from the group consisting of natural rubber and its man-made equivalents, butyl rubbers and silicone rubbers.

Claim 38

A disposable syringe assembly according to claim 29 wherein said material is natural gum rubber.

Claim 39

A disposable syringe assembly according to claim 34 wherein said natural gum rubber has a durometer of about 63 on the Shore A scale.

Claim 40

A syringe assembly according to claim 29, said wiping edge comprising a plane surface of minor dimension oriented substantially parallel to the longitudinal axis of said plunger tip.

Claim 41

A syringe assembly according to claim 36 wherein said plane surface extends radially outwardly and axially forwardly at a very slight angle.

Claim 42

A syringe assembly according to claim 37 wherein the angle is about 2°.

Claim 43

A syringe according to claim 29, including a hypodermic needle secured to said barrel for insertion into the artery of a patient to withdraw a blood sample from said patient, the frictional force of said sealing engagement being of a mangitude that allows the blood pressure of said patient to move said plunger stem and tip backwardly in said barrel to draw said blood sample from said patient into said barrel.

Claim 44

A disposable syringe assembly particularly suited because of the low force requirement for the operation thereof to be used for obtaining a blood sample from a patient comprising a barrel having a cylindrical inner wall and a plunger comprising a plunger stem and a compressible, elastomeric, generally cylindrical plunger tip of lesser diameter than the inner wall of said barrel, said plunger tip having an integral, annular, elastically deformable wiper extending peripherally radially outwardly and axially forwardly from said plunger tip at a forward portion thereof at an acute angle to the longitudinal center axis of said plunger tip and terminating at the outer edge thereof in a wiping edge having a minimal diameter slightly in excess of the diameter of the inner wall of said barrel, thereby forming a sealing engagement with the inner wall of said barrel, said annular wiper being the sole sealing element between said plunger tip and said wall, said plunger tip having a plurality of raised portions spaced circumferentially around said plunger tip and located at the rearward portion of said plunger tip, said raised portions engaging said inner wall of said barrel with a minimum of frictional contact to prevent canting of said plunger tip in said barrel, said plunger tip comprising a compressible, elastomeric material having a durometer of about 35 to 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said syringe assembly being prefilled with anticoagulant.

Claim 45

A disposable syringe assembly particularly suited because of the low force requirement for the operation thereof to be used for obtaining a blood sample from a patient comprising a barrel having a cylindrical inner wall and a plunger comprising a plunger stem and a compressible, elastomeric, generally cylindrical plunger tip of lesser diameter than the inner wall of said barrel, said plunger tip having an integral, annular, elastically deformable wiper extending peripherally radially outwardly and axially forwardly from said plunger tip at a forward portion thereof at an acute angle to the longitudinal center axis of said plunger tip and terminating at the outer edge thereof in a wiping edge having a minimal diameter slightly in excess of the diameter of the inner wall of said barrel, thereby forming a sealing engagement with the inner wall of said barrel, said annular wiper being the sole sealing element between said plunger tip and said wall, said plunger tip having a plurality of raised portions spaced circumferentially around said plunger tip and located at the rearward portion of said plunger tip, said raised portions engaging said inner wall of said barrel with a minimum of frictional contact to prevent canting of said plunger tip in said barrel, said plunger tip comprising a compressible, elastomeric material having a durometer of about 35 to 75 when measured on the Shore A scale, having the ability to retain its resilience at temperatures at least as low as 0° C., and being provided with a peripheral annular wiper lip extending axially forwardly and radially outwardly so that it forms the sole sealing element when said plunger tip is inserted in said syringe, said syringe assembly being prefilled with anticoagulant.

Claim 46

An elastomeric plunger tip according to claim 40 wherein said material has a durometer of about 50 to 70 on the Shore A scale.

Claim 47

An elastomeric plunger tip according to claim 40 wherein said material is natural gum rubber.

Claim 48

An elastomeric plunger tip according to claim 42 wherein said natural gum rubber has a durometer of about 63 on the Shore A scale.

Claim 49

An elastomeric plunger tip according to claim 40 wherein said material has the ability to retain its resilience at temperatures of about -40° C.