EP0329358A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Disposable syringe
Assignee: R & R Inventions Ltd
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Filing: 1989-02-13
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Granted: —
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Expires: 2009-02-13
Abstract
Abstract A disposable once only syringe for medical use has a tubular piston 22 connected to a piston rod 10 by a headed projection 18 20 passed through the piston bore, doubled over and then trapped in a recess 40 by a relative reverse movement of the parts. The parts are held together by the trapping of the projection in syringe filling, but upon ejection of contents the piston rod moves relative to the piston for a short distance to free the projection which allows the projection to disengage from the recess and move out of alignment with the recess. Any attempt to refill the syringe by a repeat operation causes the projection to pull through the piston and the piston rod to separate.
Inventors
- 👤 Richard Kiteley Power
- 👤 John David Yair
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 18:51
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/50; A61M5/5066
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
122 words
A disposable syringe comprises a barrel, a piston and a piston-rod; in which the piston and rod are connected together by a projection on one of them extending through a bore in the other of them, said projection having a folded over end which is, in one working position, trapped and contained in an enlargement of said bore, and the projection and bore being of such lengths as to allow for lost motion of the one relative to the other, whereby the syringe can only effect a single operational cycle before the said end disengages from the enlargement and frees the end so as to allow the piston and rod to disengage from one another if a further operational cycle is attempted.
Claim 2
Dependent Claim
122 words
A disposable syringe comprises a barrel, a piston and a piston-rod; in which the piston and rod are connected together by a projection on one of them extending through a bore in the other of them, said projection having a folded over end which is, in one working position, trapped and contained in an enlargement of said bore, and the projection and bore being of such lengths as to allow for lost motion of the one relative to the other, whereby the syringe can only effect a single operational cycle before the said end disengages from the enlargement and frees the end so as to allow the piston and rod to disengage from one another if a further operational cycle is attempted.
Claim 3
Dependent Claim
36 words
A disposable syringe as claimed in Claim 1 wherein a pair of parallel symmetrical headed projections are provided on the end of the rod and said bore enlargement is a recess concentric to the piston axis.
Claim 4
Dependent Claim
28 words
A disposable syringe as claimed in Claim 2 wherein the said recess is frusto-conical having the smaller end of the frusto-cone adjacent the free end of the piston.
Claim 5
Dependent Claim
38 words
A disposable syringe as claimed in Claim 1 wherein a first seal is provided between the piston and piston rod by a peripheral rib on the rod which is locatable within a complimentary annular zone in the piston.
Claim 6
Dependent Claim
35 words
A disposable syringe as claimed in Claim 1 wherein a second seal is provided between the piston and piston rod by a frusto-conical end of the piston and an abutting face on the piston rod.
Claim 7
Dependent Claim
62 words
A disposable syringe as claimed in Claim 4 and Claim 5 wherein the seals are disposed so that when the pisto and rod are in one position relative to one another one of the seals is effective, and after the lost motion so that the parts are in the other of their possible relative positions, the other of the seals is effective.
Claim 8
Dependent Claim
100 words
A disposable syringe as claimed in any of Claims 1-3 wherein a first seal is provided between the piston and piston rode by a portion of the rod which extends through an annular zone in the piston, said first seal being effective after relative movement between said piston and piston rod in one direction, and said piston rod being provided with one or more grooves or channels which register with said piston zone after relative movement in the opposite direction so as to allow for flow through said grooves or channels from one side of the piston to the other.
Claim 9
Dependent Claim
11 words
A disposable syringe substantially as described with reference to the drawings.
Claim 10
Dependent Claim
11 words
A disposable syringe substantially as described with reference to the drawings.
References Cited (Backward Citations)
No citation records indexed.
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