Disposable syringe

• US 4,391,272 A
• Filed: 03/09/1979
• Issued: 07/05/1983
• Est. Priority Date: 03/10/1978
• Status: Expired due to Term

• Current Assignee: Jacques Verlier
• Original Assignee: Tulcea SA
• Inventors: Staempfli, Jackie
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US06/019,251
• Time in Patent Office: 1,579 Days
• Field of Search: 128/218 P, 128/218 PA, 128/218 C, 128/218 R, 128/215, 128/216, 128/219, 128/234
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/31508 provided on the piston-rod
• CPC Class Codes: A61M 5/5013 Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe
• CPC Class Codes: A61M 5/5066 Means for preventing re-use by disconnection of piston and piston-rod
• CPC Class Codes: A61M 5/508 Means for preventing re-use by disrupting the piston seal, e.g. by puncturing

Abstract

The invention relates to a disposable syringe which is not able to be used more than once for carrying out an injection.

To this end, the syringe comprises means which permit the rearward return of at least a part of the piston body to be prevented when the said body occupies a position close to its position of maximum insertion in the cylinder. These means can, for example, be formed by a circular groove, in which can be engaged a peripheral rim of a resilient member integral with the body of the piston, thus causing the blocking of the said body.

Applications are particularly in human and veterinary medicines.

Claims

1. A disposable syringe comprising:

a cylinder, one end of which cylinder is formed with a nozzle whereby a syringe needle can be fixed to the cylinder;

an intake and delivery piston capable of sliding inside said cylinder comprising a body arranged so as to form a tight movable partition, said body having a circular groove or channel;

a rod connected with the piston body so as to permit said body to be displaced by sliding movement in the cylinder;

at least one resilient member provided in said piston body and having at least one peripheral rim or flange tending to be applied to the inside wall of said cylinder;

at least one resilient sealing joint provided in said piston of which at least one peripheral part in the form of an O-ring is retained by a wedging action between the inside wall of the cylinder and said circular groove or channel of said piston body;

at least a first circular groove, in the inside wall of said cylinder, perpendicular to the axis of the cylinder and having an edge capable of retaining the rim of the resilient member; and

at least one second circular groove, in the inside wall of said cylinder, perpendicular to the axis of the cylinder and arranged in such a way as to receive the toroidal part of the sealing joint;

whereby the said first groove and said second groove are so disposed as to cause, when the piston body is pulled in a rearward direction, the disconnection of the sealing joint from the piston body and the retention thereof in the second groove, and then the locking of the rim or edge of the resilient member against the edge of the first groove opposite to that end of the cylinder which has the nozzle.

2. A disposable syringe comprising:

a cylinder, one end of which cylinder is formed with a nozzle whereby a syringe needle can be fixed to the cylinder;

an intake and delivery piston capable of sliding within said cylinder comprising a body arranged so as to form a liquid-tight movable partition;

a rod connected with the piston body so as to permit said body to be displaced by sliding movement in the cylinder;

means for preventing the rearward return of at least a part of the piston body when said body occupies a position close to its position of maximum injection in the cylinder comprising at least one circular groove formed in the inside wall of the cylinder, perpendicular to the axis of said cylinder; and

a resilient member on said piston body having at least one peripheral rim tending to be applied to the inside wall of said cylinder;

said groove and said rim being arranged whereby, when a movement for retracting the piston from a position of maximum introduction of the piston body into the cylinder is initiated, the rim of said resilient member comes into engagement in said groove and is blocked against an edge of the latter opposite to that end of the cylinder which carries the nozzle, so as to prevent a withdrawal movement of the piston body;

an assembly member formed by a resilient block of generally frustoconical form in said piston body, the edges of the part of said block of maximum diameter forming a resilient rim tending to be applied to the internal wall of the cylinder and the block comprising a flared axial cavity, providing an internal locking edge and at least one longitudinal notch, extending through the said block from its outside wall to the inside wall of the cavity; and

a frustoconical fixing neck provided at the end of said piston rod, said neck having a bulbous portion, the shape and the dimensions of said neck and those of said assembly member being such that, before the locking of the piston body in the cylinder, the fixing neck of the piston rod is retained in the assembly member of the piston body, whereas, when the elastic rim of this member is engaged in the groove of the inside wall of the cylinder, the degree of flaring of the cavity of the assembly member increases so as to have the effect of freeing the fixing neck from the locking or engagement edge.

3. A disposable syringe comprising:

a cylinder, one end of which cylinder is formed with a nozzle whereby a syringe needle can be fixed to the cylinder;

an intake and delivery piston capable of sliding within said cylinder comprising a body arranged so as to form a liquid-tight movable partition;

a resilient end joint or packing in said piston body comprising at least one part of toroidal form;

a first circular groove or channel formed in the piston body, whereby a part of said toroidal form is retained by wedging action between the inside wall of the cylinder and said groove;

a second circular groove formed in the inside wall of the cylinder perpendicular to the axis of the cylinder, of which groove the section is sufficient to receive the toroidal part of the sealing joint of the piston, thereby causing is disengagement from said first groove or channel of the piston body, said second groove being positioned close to that end of the cylinder which carries the nozzle, in such a position that when the piston body is forced to its full extent into the cylinder, the sealing joint comes opposite to said second groove when the piston body occupies a position close to its position of maximum insertion, so that it is disengaged, under the effect of its elasticity, from said first groove or channel of the piston body, as a result becoming disconnected from said piston body, and that it remains held in said second groove if a rearward pulling action is applied to the piston body;

a rod connected with the piston body so as to permit said body to be displaced by sliding movement in the cylinder; and

means for preventing the rearward return of at least a part of the piston body when said body occupies a position close to its position of maximum injection in the cylinder.

4. The syringe of claim 3, wherein said sealing joint forms a cover capping the face of the piston body opposite to the piston rod.

5. The syringe of claim 3, wherein said sealing joint is an O-ring.

6. A disposable syringe comprising:

a cylinder, one end of which cylinder is formed with a nozzle whereby syringe needle can be fixed to the cylinder;

an intake and delivery piston capable of sliding within said cylinder comprising a body arranged so as to form a liquid-tight movable partition;

a rod connected with the piston body so as to permit said body to be displaced by sliding movement in the cylinder;

means for preventing the rearward return of at least a part of the piston body when said body occupies a position close to its position of maximum injection in the cylinder comprising at least one groove formed in the inside wall of the cylinder; and

a resilient member on said piston body having at least one peripheral rim tending to be applied to the inside wall of said cylinder;

said groove and said rim being arranged whereby, when a movement for retracting the piston from a position of maximum introduction of the piston body into the cylinder is initiated, the rim of said resilient member comes into engagement in said groove and is blocked against an edge of the latter opposite to that end of the cylinder which carries the nozzle, so as to prevent a withdrawal movement of the piston body;

an assembly member formed by a resilient block in said piston body, at least one edge of said block forming a resilient rim tending to be applied to the internal wall of the cylinder and the block comprising axial cavity, providing an internal locking edge and at least one notch, extending through said block from its outside wall to the inside wall of the cavity; and

a fixing neck provided at the end of said piston rod, whereby before the locking of the piston body in the cylinder, the fixing neck of the piston rod is retained in the assembly member of the piston body, whereas, when the elastic rim of this member is engaged in the groove of the inside wall of the cylinder, so as to have the fixing neck freed from the locking or engagement edge.

7. The syringe of claim 6, wherein

an assembly member formed with a frustoconical axial cavity is provided in said piston body;

and

a frustoconical fixing neck is provided at that end of said piston rod adjacent the piston body, said neck having a conicity corresponding to that of said cavity, and said neck being engaged with a force fit in said cavity with a force sufficient to ensure the solidarity required between the piston rod and the piston body for permitting the displacement of this body, by traction applies to the rod before the locking of the piston body in the cylinder, but sufficiently small to permit the neck to be pulled out of the cavity when the rim of the resilient member is locked against the edge of the groove.

8. The syringe of claim 6, including at least one removable safety member arranged so as to prevent the piston body from being forced into a position prior to use whereby said means for preventing the rearward return of at least a part of the piston body is prevented from coming into operation.

9. In a disposable syringe having

a cylinder, one end of which cylinder is formed with a nozzle;

an intake and delivery piston capable of sliding within said cylinder forming a liquid-tight movable partition; and

a rod connected with the piston body so as to permit said body to be displaced by sliding movement in the cylinder, the improvement which comprises at least one circular groove formed in the inside wall of the cylinder, perpendicular to the axis of said cylinder;

resilient means on said piston body which engages said groove for preventing the rearward return of at least a part of the piston body when said body occupies a position close to its position of maximum injection in the cylinder; and

means connecting said rod and said piston body which is capable of ensuring between them a sufficient solidarity for permitting the piston body to be displaced rearwardly so as to cause the intake of a liquid into the cylinder through the nozzle, by traction applied to the piston rod, when the piston body has not been placed in its end position as regards the insertion travel, said connecting means being however capable of permitting the disengagement of the piston body after the resilient member has engaged in the groove, whereby a tractive force exerted on the piston rod, after the rim of the resilient means has been blocked against the edge of the groove, has the effect of disconnecting the rod from the piston body.

10. A single-use syringe comprising in combination:

a tubular element having a plunger reciprocatably mounted in a first open end to tubular space of the tubular element and having an injection needle operably mounted on a remaining opposite end of the tubular element, a hollow portion of needle-through-space being in flow communication with tubular space of the tubular element, the improvement being at least one of (a) an interior wall of the tubular element and (b) a circumscribing lengthwise-wall of the plunger, including a male member and the other thereof including a female member preventing retraction of a terminal end-portion of the plunger when the plunger is inserted within the tubular space sufficiently for the male member to become aligned with the female member, at least one of the male member and the female member being movable such that the male member is lockable into the female member, whereby a non-reusable syringe results preventing refilling or reinjection in use thereof, said plunger including a terminal end that blocks further outflow of syringe contents when said male member is mated with said female member, and said plunger including a separable proximal end jointly movably axially to and fro prior to and until said male member is mated with said female member, said proximal end being detachable from said terminal end when withdrawal pressure is applied to said proximal end after the male member is mated with the female member whereby the terminal end continues to block outflow of syringe contents when an effort is made to withdraw the plunger.