WO2006111806A2

WO2006111806A2 - Safety syringes

Info

Publication number: WO2006111806A2
Application number: PCT/IB2006/000810
Authority: WO
Inventors: Satish Sundar
Original assignee: Indigo Orb, Inc.
Priority date: 2005-02-07
Filing date: 2006-02-07
Publication date: 2006-10-26
Also published as: WO2006111806A3

Abstract

A safety syringe, comprising : a body unit to which a needle is in use fitted; and a plunger unit which Is movably disposed to the body unit, wherein the plunger unit comprises first and second plunger members which are movable relative to one another between a first, operative configuration and a second, retracted inoperative configuration in which the needle is retracted into the body unit, a biasing element for rearwardly biasing one of the plunger members to a retracted position, and a retention member for normally retaining the plunger members in the operative configuration and being operative to release the one of the plunger members such as to be driven to the retracted position under the bias of the biasing element, wherein the one of the plunger members includes a locking member which locks to the needle when the plunger unit is depressed beyond a predeterminable position in the body unit, such that, when the one of the plunger members is released and driven to the retracted position, the needle is retracted into the body unit.

Description

SAFETY SYRINGES

The present invention relates to safety syringes, which allow for the shielding of a fitted needle following use.

Syringes have very wide application, in particular in the medical field, and safety syringes have been developed in order to reduce the risk of accidental needle sticks and other injuries, which can occur particularly during the disposal of syringes and needles from syringes.

There are numerous safety syringes available in the marketplace, for example, the Elite Safety Syringe, the NMT Safety Syringe, the BD Integra (RTM) Safety Syringe with Retracting BD Precision Glide Needle, the Vanish Point Syringe, the Safety 1^st (RTM) Safety Syringe, the Futura Safety Syringe, the SecureGard Safety Syringe, and the SafeProUSA Safety Syringe.

Whilst these syringes do function satisfactorily, a particular disadvantage of these syringes is the cost which is estimated at five to six times the cost of a standard syringe.

It is thus an aim of the present invention to provide a safety syringe which is of lower cost. This lower cost is accomplished by means of designs which have a reduced number of parts and use almost the same amount of material as a standard syringe and needle and designs for which assembly of the syringe can easily be automated or semi-automated.

In one aspect the present invention provides a safety syringe, comprising: a body unit to which a needle is in use fitted; and a plunger unit which is movably disposed to the body unit, wherein the plunger unit comprises first and second plunger members which are movable relative to one another between a first, operative configuration and a second, retracted, inoperative configuration in which the needle is retracted into the body unit, a biasing element for rearwardly biasing one of the plunger members to a retracted position, and a retention member for normally retaining the plunger members in the operative configuration and being operative to release the one of the plunger members such as to be driven to the retracted position under the bias of the biasing element, wherein the one of the plunger members includes a locking member which locks to the needle when the plunger unit is depressed beyond a predeterminable position in the body unit, such that, when the one of the plunger members is released and driven to the retracted position, the needle is retracted into the body unit.

In another aspect the present invention provides a safety syringe, comprising: a body unit to which a needle is in use fitted; and a plunger unit which is movably disposed to the body unit, wherein the plunger unit includes a locking member which is lockable to the needle, such as to allow the needle to be retracted into the body unit.

In a further aspect the present invention provides a safety syringe, comprising: a body unit to which a needle is in use fitted; and a plunger unit which is movably disposed to the body unit, wherein the plunger unit includes a locking member which is lockable to the needle, such as to allow the needle to be retracted into the body unit.

In a still further aspect the present invention provide an adapter for a delivery device, the adapter comprising: a body member which is fluidly connected to an outlet of the delivery device; a needle locking member to which a needle is locked in normal use; and a needle housing member into which the needle can be retracted.

Preferred embodiments of the present invention will now be described hereinbelow by way of example only with reference to the accompanying drawings, in which:

Figure 1 illustrates a safety syringe in accordance with a first embodiment of the present invention; Figure 2 illustrates a longitudinal sectional view (along section I-I in Figure 1) of the safety syringe of Figure 1, where in a normal, operative state;

Figure 3 illustrates an enlarged view of detail A in Figure 2;

Figure 4 illustrates a longitudinal sectional view (along section I-I in Figure 1) of the safety syringe of Figure 1, where in a first biased state as achieved by applying a first, predetermined force to the plunger unit;

Figure 5 illustrates an enlarged view of detail B in Figure 4;

Figure 6 illustrates a longitudinal sectional view (along section I-I in Figure 1) of the safety syringe of Figure 1, where in a second biased state as achieved by applying a second, higher predetermined force to the plunger unit;

Figure 7 illustrates an enlarged view of detail C in Figure 6;

Figure 8 illustrates a longitudinal sectional view (along section I-I in Figure 1) of the safety syringe of Figure 1, following retraction of the needle into the body unit;

Figure 9 illustrates an enlarged view of detail D in Figure 8;

Figure 10 illustrates a safety syringe in accordance with a second embodiment of the present invention;

Figure 11 illustrates a longitudinal sectional view (along section II-II in Figure 10) of the safety syringe of Figure 10, where in a normal, operative state;

Figure 12 illustrates an enlarged view of detail E in Figure 11; Figure 13 illustrates a longitudinal sectional view (along section II-II in Figure 12) of the safety syringe of Figure 12, where in a first biased state as achieved by applying a first, predetermined force to the plunger unit;

Figure 14 illustrates an enlarged view of detail F in Figure 13;

Figure 15 illustrates a longitudinal sectional view (along section II-II in Figure 10) of the safety syringe of Figure 10, where in a second biased state as achieved by applying a second, higher predetermined force to the plunger unit;

Figure 16 illustrates an enlarged view of detail G in Figure 15;

Figure 17 illustrates a longitudinal sectional view (along section II-II in Figure 10) of the safety syringe of Figure 10, following retraction of the needle into the body unit;

Figure 18 illustrates an enlarged view of detail H in Figure 17;

Figure 19 illustrates a safety syringe in accordance with a third embodiment of the present invention;

Figure 20 illustrates a longitudinal sectional view (along section III-III in Figure 19) of the safety syringe of Figure 19, where in a normal, operative state;

Figure 21 illustrates an enlarged view of detail I in Figure 20;

Figure 22 illustrates an enlarged view of detail J in Figure 20;

Figure 23 illustrates an enlarged view of detail K in Figure 20; Figure 24 illustrates a longitudinal sectional view (along section III-III in Figure 19) of the safety syringe of Figure 19, where in a first biased state as achieved by applying a first, predetermined force to the plunger unit;

Figure 25 illustrates an enlarged view of detail L in Figure 24;

Figure 26 illustrates a longitudinal sectional view (along section III-III in Figure 19) of the safety syringe of Figure 19, where in a second biased state as achieved by applying a second, higher predetermined force to the plunger unit;

Figure 27 illustrates an enlarged view of detail M in Figure 26;

Figure 28 illustrates a longitudinal sectional view (along section III-III in Figure 19) of the safety syringe of Figure 19, following retraction of the needle into the body unit;

Figure 29 illustrates an enlarged view of detail N in Figure 28;

Figure 30 illustrates a safety syringe in accordance with a fourth embodiment of the present invention;

Figure 31 illustrates a vertical sectional view of the safety syringe of Figure 30, where in a normal, operative state;

Figure 32 illustrates an enlarged view of detail O in Figure 31;

Figure 33 illustrates a vertical sectional view of the safety syringe of Figure 30, following retraction of the needle into the adapter unit;

Figure 34 illustrates an enlarged view of detail P in Figure 33;

Figure 35 illustrates a safety syringe in accordance with a fifth embodiment of the present invention; Figure 36 illustrates a longitudinal sectional view (along section IV-IV in Figure 35) of the safety syringe of Figure 35, where in a normal, operative state;

Figure 37 illustrates an enlarged, fragmentary view of detail in Figure 36;

Figure 38 illustrates a longitudinal sectional view (along section IV-IV in Figure 35) of the safety syringe of Figure 35, where the plunger unit has been depressed to a forward end of the body unit;

Figure 39 illustrates an enlarged, fragmentary view of detail in Figure 38;

Figure 40 illustrates a longitudinal sectional view (along section IV-IV in Figure 35) of the safety syringe of Figure 35, where in a first biased state as achieved by applying a first, predetermined force to the plunger unit;

Figure 41 illustrates an enlarged, fragmentary view of detail in Figure 40;

Figure 42 illustrates a longitudinal sectional view (along section IV-IV in Figure 35) of the safety syringe of Figure 35, where in a second biased state as achieved by applying a second, higher predetermined force to the plunger unit;

Figure 43 illustrates an enlarged, fragmentary view of detail in Figure 42;

Figure 44 illustrates a longitudinal sectional view (along section IV-IV in Figure 35) of the safety syringe of Figure 35, following retraction of the needle into the body unit; and

Figure 45 illustrates an enlarged, fragmentary view of detail in Figure 44.

Figures 1 to 9 illustrate a safety syringe in accordance with a first embodiment of the present invention. The safety syringe comprises a body unit 3 to which a needle 5 is fitted and a plunger unit 7 which is movably disposed relative to the body unit 3, such as to enable a volume of liquid to be drawn into and expelled from the body unit 3 and also provide for automatic retraction of the needle 5 into the body unit 3 following use.

The body unit 3 comprises a barrel 9, in this embodiment an elongate, tubular cylindrical body, one, rear end of which is open and includes flange elements 11 by which a user grips the barrel 9, and the other, forward end of which is closed and includes a needle locking member 15 to which the needle 5 is locked in normal use and a release member 17 which is operative in providing for the retraction of the needle 5, as will be described in more detail hereinbelow.

In this embodiment the needle locking member 15 comprises a rearwardly- directed, flexible annular element 19, which has an inner surface 21 which tapers outwardly in the rearward direction and includes a locking detent 23, in this embodiment a forwardly-facing lip, which, with the annular element 19 in the locking configuration, acts to engage the locking element 41 of the coupling member 33 of the needle 5 and lock the needle 5 to the body unit 3. As will be described in more detail hereinbelow, the annular element 19 is configured such as to be splayed outwardly on the application of an outwardly-directed force thereto, with the splaying of the annular element 19 acting to displace the locking detent 23 thereof outwardly, such as to release the same from the locking element 41 of the coupling member 33 of the needle 5 and thereby provide for retraction of the needle 5.

In this embodiment the annular element 19 is a continuous element, with the required flexibility being provided by the shape and size of the annular element, but in other embodiments could include slots such as to provide the required flexibility. In an alternative embodiment the locking member 15 could, instead of the annular element 19, include a plurality of flexible arms, which together define the tapering engagement surface 21 and the locking detent 23.

In this embodiment the release member 17 comprises an annular element 27 which defines an engagement surface 29 for engagement with the counterpart release member 65 of the plunger unit 7 in releasing the inner plunger member 53 from the outer plunger member 51 to cause retraction of the needle 5, as will be described in more detail hereinbelow.

In an alternative embodiment the release member 17 could comprise a plurality of projections which together define the engagement surface 29 for engagement with the counterpart release member 65 of the plunger unit 7.

In this embodiment the engagement elements 27 are substantially rearwardly directed and the engagement surface 29 is an outer surface which tapers outwardly in the forward direction.

In this embodiment the needle 5 comprises a needle element 31, in this embodiment an elongate tubular element, typically of stainless steel, and a coupling member 33 which is disposed to one, the rear, end of the needle element 31.

The coupling member 33 comprises a body element 35 which includes a through bore 37 which is fluidly connected to the needle element 31 and provides for fluid communication with the interior of the body unit 3, a locking element 41, in this embodiment an outwardly-directed annular flange, which acts to lock the needle 5 to the body unit 3 when located forwardly of and engaged by the locking detent 23 of the locking member 15 of the body unit 3, and an attachment element 43 by which the inner plunger member 53 of the plunger unit 7 is attached to the needle 5, such as to allow for retraction of the needle 5. In this embodiment the attachment element 43 includes an engagement surface 45, in this embodiment a forwardly-facing lip, by which the inner plunger member 53 of the plunger unit 7 is attached to the needle 5, and a sliding surface 47 which provides for the sliding of the attachment member 83 of the inner plunger member 53 thereover.

The plunger unit 7 comprises a first, outer plunger member 51, a second, inner plunger member 53 which is movably disposed within the outer plunger member 51, a sealing member 55, in this embodiment a compliant sealing gasket, which is disposed to a forward end of the outer plunger member 51 and acts to provide a seal with the inner surface of the barrel 9 of the body unit 3 such as to define a chamber 57 into which liquid can be drawn and expelled, and a biasing element 59, in this embodiment a compression spring, which acts to bias the inner plunger member 53 to a retracted position, as will be described in more detail hereinbelow.

In this embodiment the outer plunger member 51 comprises a body element 61, here a tubular cylindrical body, a supporting element 63, here an inwardly-directed flange, which is disposed to one, the forward, end of the body element 61, and a retention member 65 which is disposed to the supporting element 63, in this embodiment extending forwardly thereof, and is movable between a first, normal configuration, as illustrated in Figures 2 to 4, which acts to retain the inner plunger member 53 in the normal, operative state, and a second, splayed configuration, as illustrated in Figures 6 and I₁ which is achieved by splaying the retention member 65 outwardly and provides for release of the inner plunger member 53 to the retracted position, as illustrated in Figures 8 and 9.

In this embodiment the retention member 65 comprises an annular element 67 which includes an engagement surface 69, here a forwardly-facing annular lip, which acts to engage an engagement member 81 of the inner plunger member 53 and retain the same in the normal, operative position, and a release surface 71, in this embodiment an inner surface which tapers outwardly in the forward direction and is operative to engage the counterpart release surface 27 of the release member 19 at the forward end of the body unit 3, such that, when the plunger unit 7 is biased forwardly with a sufficient biasing force, the retention member 65 is splayed outwardly and the engagement surface 69 of the retention member 65 is released from engagement with the engagement member 81 of the inner plunger member 53.

In this embodiment the inner plunger member 53 comprises a body member 77, a supporting member 79 which is disposed at the rearward end of the body member 77 and is engaged by the biasing element 59 such as to bias the same in the rearward direction, an engagement member 81, in this embodiment an outwardly-directed annular flange, which acts normally to engage the engagement surface 69 of the retention member 65 of the outer plunger member 51 and retain the inner plunger member 53 in the normal, operative position, and a locking member 83 which acts to lock to the coupling member 33 of the needle 5 when pushed thereover on applying a predetermined biasing force to the plunger unit 7, as illustrated in Figures 4 and 5.

In this embodiment the attachment member 83 comprises an annular element 85 which includes an inwardly-facing sliding surface 87 which tapers outwardly in the forward direction and is configured to engage the sliding surface 47 of the coupling member 33 of the needle 5 such as to allow for sliding of the same thereover, and a rearwardly-directed locking surface 89, in this embodiment an annular lip, which is configured to engage the locking surface 45 of the coupling member 33 of the needle 5, such that, when locked thereto, retraction of the inner plunger member 53 rearwardly into the outer plunger member 51 acts to retract the needle 5 into the body unit 3.

In this embodiment the sealing member 55, in addition to providing a seal with the barrel 9 of the body unit 3, is configured so as to provide a biasing force in the longitudinal direction which, when the plunger unit 7 is depressed to the forward end of the body unit 3, acts to counteract the biasing force as applied by the user in depressing the plunger unit 7, with the biasing force being such that a first, predetermined biasing force has to be developed to achieve the locking configuration, as illustrated in Figures 4 and 5, and a second, higher biasing force has to be developed to achieve the release configuration, as illustrated in Figures 6 and 7, which allows the inner plunger member 53 and the needle 5 as locked thereto to be automatically retracted to the retracted position, as illustrated in Figures 8 and 9.

In this embodiment the sealing member 55 is a compliant gasket, such as a rubberized component, which provides the biasing force, but in an alternative embodiment the sealing member 55 could be a non-compliant gasket, such as an o-ring or a quad-ring, and instead a separate biasing element could be utilized to provide the biasing force. In one embodiment the separate biasing element could be a compression spring, but in other embodiments could comprise one or more flexible elements or a pneumatic element.

Figures 10 to 18 illustrate a safety syringe in accordance with a second embodiment of the present invention.

The safety syringe comprises a body unit 103 to which a needle 105 is fitted and a plunger unit 107 which is movably disposed relative to the body unit 103, such as to enable a volume of liquid to be drawn into and expelled from the body unit 103 and also provide for automatic retraction of the needle 105 into the body unit 103 following use.

The body unit 103 comprises a barrel 109, in this embodiment an elongate, tubular cylindrical body, one, rear end of which is open and includes flange elements 111 by which a user grips the barrel 109, and the other, forward end of which is closed and includes a needle locking member 115 to which the needle 105 is locked in normal use and a release member 117 which is operative in providing for the retraction of the needle 105, as will be described in more detail hereinbelow. In this embodiment the needle locking member 115 comprises a rearwardly- directed annular element 119 which includes a locking detent 123, in this embodiment an inwardly-projecting lip, which acts to engage the locking element 141 of the coupling member 133 of the needle 105 and lock the needle 105 to the body unit 103. As will be described in more detail hereinbelow, the annular element 119 and the locking detent 123 thereof, together with the locking element 141 of the coupling member 133 of the needle 5, have sufficient resilience as to allow the locking element 141 of the coupling member 133 to be drawn over the locking detent 123, such as to release the same from the locking element 141 of the coupling member 133 and thereby provide for retraction of the needle 105.

In this embodiment the annular element 119 is a continuous element, but in other embodiments could be slotted such as to provide the required flexibility in allowing for the unlocking of the needle 105 from the needle locking member 115.

In an alternative embodiment the locking member 115 could, instead of the annular element 119, include a plurality of flexible arms.

In an alternative embodiment the locking member 115 could be a substantially rigid structure, and instead the locking element 141 of the coupling member 133 could be a frangible element, which fractures on the application of a predetermined force thereto, as achieved in retracting the needle 105, but not encountered in normal use of the syringe.

In this embodiment the release member 117 comprises an annular element 127 which defines a release surface 129 for engagement with the counterpart release member 165 of the plunger unit 107 in releasing the inner plunger member 153 from the outer plunger member 151 to cause retraction of the needle 105, as will be described in more detail hereinbelow. In an alternative embodiment the release member 117 could comprise a plurality of projections which together define the release surface 129 for engagement with the counterpart release member 165 of the plunger unit 107.

In this embodiment the annular element 127 is substantially rearwardly directed and the engagement surface 129 is an outer surface which tapers outwardly in the forward direction.

In this embodiment the needle 105 comprises a needle element 131, in this embodiment an elongate tubular element, typically of stainless steel, and a coupling member 133 which is disposed to one, the rear, end of the needle element 131.

The coupling member 133 comprises a body element 135 which includes a through bore 137 which is fluidly connected to the needle element 131 and provides for fluid communication with the interior of the body unit 103, a locking element 141, in this embodiment an outwardly-directed annular flange, which acts to lock the needle 105 to the body unit 103 when located forwardly of and engaged by the locking detent 123 of the needle locking member 115 of the body unit 103, and an attachment element 143 by which the inner plunger member 153 of the plunger unit 107 is attached to the needle 105, such as to allow for retraction of the needle 105.

In this embodiment the attachment element 143 includes an engagement surface 145, here a forwardly-facing lip, by which the inner plunger member 153 of the plunger unit 107 is attached to the needle 105, and a sliding surface 147 which provides for the sliding of the attachment member 183 of the inner plunger member 153 thereover.

The plunger unit 107 comprises a first, outer plunger member 151, a second, inner plunger member 153 which is movably disposed within the outer plunger member 151, a sealing member 155, in this embodiment a compliant sealing gasket, which is disposed to a forward end of the outer plunger member 151 and acts to provide a seal with the inner surface of the barrel 109 of the body unit 103 such as to define a chamber 157 into which liquid can be drawn and expelled, and a biasing element 159, in this embodiment a compression spring, which acts to bias the inner plunger member 153 to a retracted position, as will be described in more detail hereinbelow.

In this embodiment the outer plunger member 151 comprises a body element 161, here a tubular cylindrical body, a supporting element 163, here an inwardly-directed flange, which is disposed to one, the forward, end of the body element 161, and a retention member 165 which is disposed to the supporting element 163, in this embodiment extending forwardly thereof, and is movable between a first, normal configuration, as illustrated in Figures 11 to 14, which acts to retain the inner plunger member 153 in the normal, operative state, and a second, splayed configuration, as illustrated in Figures 15 and 16, which is achieved by splaying the retention member 165 outwardly and provides for release of the inner plunger member 153 to the retracted position, as illustrated in Figures 17 and 18.

In this embodiment the retention member 165 comprises an annular element 167 which includes an engagement surface 169, here a forwardly- facing annular lip, which acts to engage the engagement member 181 of the inner plunger member 153 and retain the same in the normal, operative position, and a release surface 171, in this embodiment an inner surface which tapers outwardly in the forward direction and is operative to engage the counterpart release surface 129 of the release member 117 at the forward end of the body unit 103, such that, when the plunger unit 107 is biased forwardly with a sufficient biasing force, the retention member 165 is splayed outwardly and the engagement surface 169 of the retention member 165 is released from engagement with the engagement member 181 of the inner plunger member 153, as illustrated in Figures 15 and 16.

In this embodiment the inner plunger member 153 comprises a body member 177, a supporting member 179 which is disposed at the rearward end of the body member 177 and is engaged by the biasing element 159 such as to bias the same in the rearward direction, an engagement member 181, in this embodiment defining a rearwardly-facing engagement lip, which acts normally to engage the engagement surface 169 of the retention member 165 of the outer plunger member 151 and retain the inner plunger member 153 in the normal, operative position, and a locking member 183, as an extension of the engagement member 181, which acts to lock to the coupling member 133 of the needle 105 when pushed thereover on applying a predetermined biasing force to the plunger unit 103, as illustrated in Figures 13 and 14.

In this embodiment the attachment member 183 comprises an annular element 185 which includes an inwardly-facing sliding surface 187 which tapers outwardly in the forward direction and is configured to engage the sliding surface 147 of the coupling member 133 of the needle 105 such as to allow for sliding of the same thereover, and a rearwardly-directed locking surface 189, in this embodiment an annular lip, which is configured to engage the locking surface 145 of the coupling member 133 of the needle 105, such that, when locked thereto, retraction of the inner plunger member 153 rearwardly into the outer plunger member 151 acts to retract the needle 105 into the body unit 103, as illustrated in Figures 17 and 18.

In this embodiment the sealing member 155, in addition to providing a seal with the barrel 109 of the body unit 103, is configured so as to provide a biasing force in the longitudinal direction which, when the plunger unit 107 is depressed to the forward end of the body unit 103, acts to counteract the biasing force as applied by the user in depressing the plunger unit 103, with the biasing force being such that a first, predetermined biasing force has to be developed to achieve the locking configuration, as illustrated in Figures 13 and 14, and a second, higher biasing force has to be developed to achieve the release configuration, as illustrated in Figures 15 and 16, which allows the inner plunger member 153 and the needle 105 as locked thereto to be automatically retracted to the retracted position, as illustrated in Figures 17 and 18. In this embodiment the sealing member 155 is a compliant gasket, such as a rubberized component, which provides the biasing force, but in an alternative embodiment the sealing member 155 could be a non-compliant gasket, such as an o-ring or a quad-ring, and instead a separate biasing element could be utilized to provide the biasing force. In one embodiment the separate biasing element could be a compression spring, but in other embodiments could comprise one or more flexible elements or a pneumatic element.

Figures 19 to 29 illustrate a safety syringe in accordance with a third embodiment of the present invention.

The safety syringe comprises a body unit 203 to which a needle 205 is fitted, and a plunger unit 207 which is movably disposed relative to the body unit 203, such as to enable a volume of liquid to be drawn into and expelled from the body unit 203 and also provide for automatic retraction of the needle 205 into the body unit 203 following use.

The body unit 203 comprises a barrel 209, in this embodiment an elongate, tubular cylindrical body, one, rear end of which is open and includes flange elements 211 by which a user grips the barrel 209, and the other, forward end of which is closed and includes a needle locking member 215 to which the needle 205 is locked in normal use and a release member 217 which is operative in providing for the retraction of the needle 205, as will be described in more detail hereinbelow.

In this embodiment the needle locking member 215 comprises a rearwardly- directed annular element 219 which includes a locking detent 223, in this embodiment an inwardly-projecting lip, which acts to engage the locking element 241 of the coupling member 233 of the needle 205 and lock the needle 205 to the body unit 203. As will be described in more detail hereinbelow, the annular element 219 and the locking detent 223 thereof, together with the locking element 241 of the coupling member 233 of the needle 205, have sufficient resilience as to allow the locking element 241 of the coupling member 233 to be drawn over the locking detent 223, such as to release the same from the locking element 241 of the coupling member 233 and thereby provide for retraction of the needle 205.

In this embodiment the annular element 219 is a continuous element, but in other embodiments could be slotted such as to provide the required flexibility in allowing for the unlocking of the needle 205 from the needle locking member 215.

In this embodiment the release member 217 comprises an annular element 227, as an extension of the annular element 219, which defines a release surface 229 for engagement with the counterpart release member 265 of the plunger unit 207 in releasing the inner plunger member 253 from the outer plunger member 251 to cause retraction of the needle 205, as will be described in more detail hereinbelow.

In an alternative embodiment the release member 217 could comprise a plurality of projections which together define the release surface 229 for engagement with the counterpart release member 265 of the plunger unit 207.

In this embodiment the annular element 227 is substantially rearwardly directed and the engagement surface 229 is an outer surface which tapers outwardly in the forward direction.

In this embodiment the needle 205 comprises a needle element 231, in this embodiment an elongate tubular element, typically of stainless steel, and a coupling member 233 which is disposed to one, the rear, end of the needle element 231.

The coupling member 233 comprises a body member 235 which includes a through bore 237 which is fluidly connected to the needle element 231 and provides for fluid communication with the interior of the body unit 203, a locking element 241, in this embodiment an outwardly-directed annular flange, which acts to lock the needle 205 to the body unit 203 when located forwardly of and engaged by the locking detent 223 of the locking member 215 of the body unit 203, and an attachment element 243 by which the inner plunger member 253 of the plunger unit 207 is attached to the needle 205, such as to allow for retraction of the needle 205, as illustrated in Figures 28 and 29.

In this embodiment the attachment element 243 includes an engagement surface 245, in this embodiment a forwardly-facing lip, by which the inner plunger member 253 of the plunger unit 207 is attached to the needle 205.

The plunger unit 207 comprises a first, outer plunger member 251, a second, inner plunger member 253 which is movably disposed within the outer plunger member 251, a sealing member 255, in this embodiment a compliant sealing gasket, which is disposed to a forward end of the outer plunger member 251 and acts to provide a seal with the inner surface of the barrel 209 of the body unit 203 such as to define a chamber 257 into which liquid can be drawn and expelled, and a biasing element 259, in this embodiment a compression spring, which acts to bias the inner plunger member 253 to a retracted position, as will be described in more detail hereinbelow.

In this embodiment the outer plunger member 251 comprises a body member 261, here a tubular cylindrical body, a supporting member 263, here an inwardly-directed flange, which is disposed to one, the forward, end of the body member 261, and an engagement member 265, as a radial extension of the supporting member 263.

In this embodiment the engagement member 265 includes an engagement surface 269, here a forwardly-facing annular lip, which acts to engage an engagement member 281 of the inner plunger member 253 and retain the same in the normal, operative position. In this embodiment the inner plunger member 253 comprises a body member 277, which is engaged by the biasing element 259 such as to bias the same in the rearward direction, and a combined retention and attachment member 281 which is disposed to the body member 277, in this embodiment extending forwardly thereof, and is movable between a first, normal configuration, as illustrated in Figures 20, 22, 24 and 25, which acts to retain the inner plunger member 253 in the normal, operative state, and a second, splayed configuration, as illustrated in Figures 26 and 27 which is achieved by splaying the combined retention and attachment member 281 inwardly and provides for release of the inner plunger member 253 to the retracted position, as illustrated in Figures 28 and 29.

In this embodiment the combined retention and attachment member 281 comprises a slotted annular element 287 which includes a first, outer engagement surface 289, here a rearwardly-facing annular lip, which acts to engage the engagement member 265 of the inner plunger member 253 and retain the same in the normal, operative position, and a release surface 291, in this embodiment an outer surface which tapers outwardly in the rearward direction and is operative to engage the counterpart release surface 229 of the release member 217 at the forward end of the body unit 203, such that, when the plunger unit 207 is biased forwardly with a sufficient biasing force, the combined retention and attachment member 281 is splayed inwardly and the outer engagement surface 289 of the retention member 281 is released from engagement with the engagement member 265 of the inner plunger member 253, as illustrated in Figures 26 and 27.

In this embodiment the combined retention and attachment member 281 further includes an inwardly-directed annular element 295 which includes a rearwardly-facing locking surface 297, in this embodiment an annular lip, which is configured to engage the locking surface 245 of the coupling member 233 of the needle 205, such that, when locked thereto, retraction of the inner plunger member 253 rearwardly into the outer plunger member 251 acts to retract the needle 205 into the body unit 203. In this embodiment the combined retention and attachment member 281 and the attachment member 243 of the coupling member 233 of the needle 205 are configured to require a predetermined biasing force to the plunger unit 203 to achieve the locking configuration, as illustrated in Figures 24 and 25, and a second, higher biasing force has to be developed to achieve the release configuration, as illustrated in Figures 26 and 27, which allows the inner plunger member 253 and the needle 2055 as locked thereto to be automatically retracted to the retracted position, as illustrated in Figures 28 and 29.

In this embodiment the sealing member 255 is a compliant gasket, such as a rubberized component, but in an alternative embodiment the sealing member 255 could be a non-compliant gasket, such as an o-ring or a quad- ring. In one embodiment a separate biasing element could be utilized to provide a biasing force which counteracts the biasing force as applied to the plunger unit 207 as applied by the user. In one embodiment the separate biasing element could be a compression spring, but in other embodiments could comprise one or more flexible elements or a pneumatic element.

Figures 30 to 34 illustrate a safety syringe in accordance with a fourth embodiment of the present invention.

The safety syringe comprises a syringe 301 and an adapter unit 302 which is fitted to the syringe 301 and provides a retractable needle 305.

The syringe 301 comprises a body unit 303 to which the adapter unit 302 is fitted, and a plunger unit 307 which is movably disposed relative to the body unit 303, such as to enable a volume of liquid to be drawn into and expelled from the body unit 303.

The body unit 303 comprises a barrel 309, in this embodiment an elongate, tubular cylindrical body, one, rear end of which is open and includes flange elements 311 by which a user grips the barrel 309, and the other, forward end of which is attached to the adapter unit 302. In this embodiment the adapter unit 302 comprises a body member 311 which is fluidly connected to the outlet of the body unit 303 of the syringe 301, a needle locking member 315 to which the needle 305 is locked in normal use, a needle housing member 317 into which the needle 305 can be retracted, and a biasing element 319, in this embodiment a compression spring, which acts to bias the needle 305 rearwardly into the needle housing member 317.

In this embodiment the needle locking member 315 comprises an annular element 321 which includes a locking detent 323, which acts to engage the locking element 341 of the coupling member 333 of the needle 305 and lock the needle 305 to the body unit 303, such that the locking element 341 of the coupling member 333 and the locking detent 323 together act in the manner of a releasable clip.

In this embodiment the needle 305 comprises a needle element 331, in this embodiment an elongate tubular element, typically of stainless steel, and a coupling member 333 which is disposed to one, the rear, end of the needle element 331.

The coupling member 333 comprises a body member 335 which includes a lateral bore 337 which is fluidly connected to the needle element 331 and provides for fluid communication with the body member 311 of the adapter unit 302 when the needle 305 is in the extended, operative position, and a locking element 341, in this embodiment in the form of outwardly-directed clips, which act to lock the coupling member 333 to the needle locking member 315 when located forwardly of and engaged by the locking detent 323 of the locking member 315.

In this embodiment the locking element 341 is manually operated by a user to release the needle 305 from the locked position, as illustrated in Figures 31 and 32, to a retracted position, as illustrated in Figures 33 and 34, in which the needle element 331 of the needle 305 is concealed within the needle housing member 317.

In this embodiment the sealing member 355 is a compliant gasket, such as a rubberized component, but in an alternative embodiment the sealing member 355 could be a non-compliant gasket, such as an o-ring or a quad- ring.

Figures 35 to 45 illustrate a safety syringe in accordance with a fifth embodiment of the present invention.

The safety syringe comprises a body unit 403 to which a needle 405 is fitted and a plunger unit 407 which is movably disposed relative to the body unit 403, such as to enable a volume of liquid to be drawn into and expelled from the body unit 403 and also provide for automatic retraction of the needle 405 into the body unit 403 following use.

The body unit 403 comprises a barrel 409, in this embodiment an elongate, tubular cylindrical body, one, rear end of which is open and includes flange elements 411 by which a user grips the barrel 409, and the other, forward end of which is closed and includes a needle locking member 415 to which the needle 405 is locked in normal use.

In this embodiment the needle locking member 415 comprises a plurality of forwardly-directed, flexible arm elements 419, which include an inner surface 421 which tapers outwardly in the rearward direction and a locking detent 423, in this embodiment a forwardly-facing lip, which, with the arm elements 419 in the locking configuration, act to engage the locking element 441 of the coupling member 433 of the needle 405 and lock the needle 405 to the body unit 403. As will be described in more detail hereinbelow, the arm elements 419 are configured such as to be splayed outwardly on the application of an outwardly-directed force thereto, with the splaying of the arm elements 419 acting to displace the locking detents 423 thereof outwardly, such as to release the same from the locking element 441 of the coupling member 433 of the needle 405 and thereby provide for retraction of the needle 405.

In this embodiment the needle 405 comprises a needle element 431, in this embodiment an elongate tubular element, typically of stainless steel, and a coupling member 433 which is disposed to one, the rear, end of the needle element 431.

The coupling member 433 comprises a body element 435 which includes a through bore 437 which is fluidly connected to the needle element 431 and provides for fluid communication with the interior of the body unit 403, a locking element 441, in this embodiment an outwardly-directed annular flange, which acts to lock the needle 405 to the body unit 403 when located forwardly of and engaged by the locking detents 423 of the needle locking member 415 of the body unit 403, and an attachment element 443 by which the inner plunger member 453 of the plunger unit 407 is attached to the needle 405, such as to allow for retraction of the needle 405.

In this embodiment the attachment element 443 includes an engagement surface 445, in this embodiment a forwardly-facing lip, by which the inner plunger member 453 of the plunger unit 407 is attached to the needle 405, and a sliding surface 447 which provides for the sliding of the attachment member 483 of the inner plunger member 453 thereover.

The plunger unit 407 comprises a first, outer plunger member 451, a second, inner plunger member 453 which is movably disposed within the outer plunger member 451, a sealing member 455, in this embodiment a compliant sealing gasket, which is disposed to a forward end of the outer plunger member 451 and acts to provide a seal with the inner surface of the barrel 409 of the body unit 403 such as to define a chamber 457 into which liquid can be drawn and expelled, and a biasing element 459, in this embodiment a resilient bellows structure, which acts to bias the inner plunger member 453 to a retracted position, as will be described in more detail hereinbelow. In this embodiment the outer plunger member 451 comprises first and second body elements 461, 462, here tubular cylindrical bodies, which are captively slideably disposed to one another between an extended state as normally maintained by the biasing element 459, as illustrated in Figures 36 and 37, and a collapsed state, as illustrated in Figures 42 and 43.

In this embodiment the second, inner body element 462 of the outer plunger member 451 is fixedly connected to the sealing member 455, in this embodiment to one, the forward, end thereof, and the biasing element 459 is supported at one, the forward, end by the sealing member 455.

In this embodiment the first, outer body element 461 of the outer plunger member 451 includes a retention member 465, which is movable between a first, normal configuration, as illustrated in Figures 36 and 37, which acts to retain the inner plunger member 453 in the normal, operative state, and a second, splayed configuration, as illustrated in Figures 42 and 43, which is achieved by splaying the retention member 465 outwardly and provides for release of the inner plunger member 453 to the retracted position, as illustrated in Figures 44 and 45.

In this embodiment the retention member 465 comprises a plurality of arm elements 467 which includes an engagement surface 469, here a forwardly- facing surface, which acts to engage the inner plunger member 453, in this embodiment the rear end thereof, and retain the same in the normal, operative position, and a release surface 471, in this embodiment an inner surface which tapers inwardly in the rearward direction and is operative to engage the inner body element 462 of the outer plunger member 451, such that, when the plunger unit 407 is biased forwardly with a sufficient biasing force as to cause the inner and outer body elements 461, 462 to be slid over one another to the collapsed state, the retention member 465 is splayed outwardly and the engagement surface 469 of the retention member 465 is released from engagement with the inner plunger member 453. In this embodiment the inner plunger member 453 comprises a body member 477, a supporting member 479 which is disposed at the rearward end of the body member 477 and is engaged by the other, rear end of the biasing element 459 such as to bias the same in the rearward direction, and a locking member 483 which acts to lock to the coupling member 433 of the needle 405 when pushed thereover on applying a predetermined biasing force to the plunger unit 407, as illustrated in Figures 40 and 41.

In this embodiment the attachment member 483 comprises an annular element 485 which includes an inwardly-facing sliding surface 487 which tapers outwardly in the forward direction and is configured to engage the sliding surface 447 of the coupling member 433 of the needle 405 such as to allow for sliding of the same thereover, and a rearwardly-directed locking surface 489, in this embodiment an annular lip, which is configured to engage the locking surface 445 of the coupling member 433 of the needle 405, such that, when locked thereto, retraction of the inner plunger member 453 rearwardly into the outer plunger member 451 acts to retract the needle 405 into the body unit 403.

In this embodiment the biasing element 459 is configured so as to provide a biasing force in the longitudinal direction which, when the plunger unit 407 is depressed to the forward end of the body unit 403, acts to counteract the biasing force as applied by the user in depressing the plunger unit 407, with the biasing force being such that a first, predetermined biasing force has to be developed to achieve the locking configuration, as illustrated in Figures 40 and 41, and a second, higher biasing force has to be developed to achieve the release configuration, as illustrated in Figures 42 and 43, which allows the inner plunger member 453 and the needle 405 as locked thereto to be automatically retracted to the retracted position, as illustrated in Figures 44 and 45.

In this embodiment the sealing member 455 is a compliant gasket, such as a rubberized component, but in an alternative embodiment the sealing member 455 could be a non-compliant gasket, such as an o-ring or a quad- ring.

Finally, it will be understood that the present invention has been described in its preferred embodiment and can be modified in many different ways without departing from the scope of the invention as defined by the appended claims.

For example, in one modification of the first-described embodiment, the needle 5 could be located within the body unit 3 and include a cap member at the distal end thereof which allows the needle 5 to be drawn out into the locked configuration, in which the locking element 41 of the coupling member 33 of the needle is engaged by the locking member 15 of the body unit 3. With this configuration, a user is not exposed to the sharp needle element 31 prior to use of the syringe.

In one embodiment the needles 5, 105, 205, 305 can be fabricated from standard needles where a jacket is fitted over the standard locking fitment.

In one embodiment the safety syringe of the above-described fourth embodiment could be utilized in an automated injection station, where injections are made automatically in accordance with a predefined regime and disposed of following injection. In such an automated embodiment the barrel and plunger arrangement of a conventional syringe could be replaced by a pre-filled module, such as a flexible member or a bellows which is collapsed to deliver a predetermined dose.

In one embodiment of the fourth embodiment the syringe 301 can be pre- filled with a predetermined dose of substance.

In one embodiment the safety syringe of the above-described fourth embodiment could be modified to actuate the needle retraction mechanism in response to depression of the plunger unit beyond a predetermined location. In order to ensure that all of the contained dose is delivered prior to actuation of the needle retraction mechanism, the sealing member can be provided with sufficient compliance in the direction of plunger movement as to ensure complete evacuation of the chamber.

In the fourth-described embodiment the needle retraction mechanism could, instead of a manual mechanism, be a pneumatic, magnetic or electromagnetic mechanism.

In the fourth-described embodiment the adaptor unit 302 could be modified so as to be co-axial with the outlet of the syringe 301.

Claims

1. A safety syringe, comprising: a body unit to which a needle is in use fitted; and a plunger unit which is movably disposed to the body unit, wherein the plunger unit comprises first and second plunger members which are movable relative to one another between a first, operative configuration and a second, retracted, inoperative configuration in which the needle is retracted into the body unit, a biasing element for rearwardly biasing one of the plunger members to a retracted position, and a retention member for normally retaining the plunger members in the operative configuration and being operative to release the one of the plunger members such as to be driven to the retracted position under the bias of the biasing element, wherein the one of the plunger members includes a locking member which locks to the needle when the plunger unit is depressed beyond a predeterminable position in the body unit, such that, when the one of the plunger members is released and driven to the retracted position, the needle is retracted into the body unit.

2. The syringe of claim 1, wherein the body unit includes a needle locking member which acts to lock the needle to the body unit.

3. The syringe of claim 2, wherein the needle locking member includes a locking detent which normally acts to engage the needle such as to lock the same to the body unit and, when released from engagement, allows for retraction of the needle.

4. The syringe of claim 3, wherein the needle locking member comprises a flexible element which supports the locking detent, wherein the locking detent is released from engagement with the needle by deflecting the flexible element.

5. The syringe of claim 4, wherein the flexible element is configured such as to be deflected by the plunger unit.

6. The syringe of claim 4 or 5, wherein the flexible element comprises an annular element and the locking detent is released from engagement with the needle by splaying the annular element.

7. The syringe of claim 6, wherein the annular element comprises a continuous annular element.

8. The syringe of claim 6, wherein the annular element comprises a slotted annular element.

9. The syringe of claim 2, wherein the needle locking member provides for frictional engagement of the needle to the body unit, which frictional engagement is such as to provide for normal operation of the syringe.

10. The syringe of claim 9, wherein one or both of the needle locking member and the needle include surface features which provide for a predeterminable frictional engagement therebetween.

11. The syringe of any of claims 1 to 10, wherein the retention member comprises a flexible element which, when deflected, releases the one of the plunger members to be driven to the retracted position.

12. The syringe of claim 11, wherein the flexible element is configured such as to be deflected on engaging a release surface on the body unit.

13. The syringe of claim 11 or 12, wherein the flexible element comprises an annular element which is splayed to release the one of the plunger members.

14. The syringe of claim 13, wherein the annular element comprises a continuous annular element.

15. The syringe of claim 13, wherein the annular element comprises a slotted annular element.

16. The syringe of any of claims 1 to 15, wherein the other of the plunger members includes the retention member.

17. The syringe of claim 16, wherein the retention member includes a forwardly-facing engagement surface which acts normally to engage the one of the plunger members and retain the plunger members in the operative configuration, which engagement, when released, provides for the one of the plunger members to be driven to the retracted position.

18. The syringe of any of claims 1 to 15, wherein the one of the plunger members includes the retention member.

19. The syringe of claim 18, wherein the retention member includes a rearwardly-facing engagement surface which acts normally to engage the other of the plunger members and retain the plunger members in the operative configuration, which engagement, when released, provides for the one of the plunger members to be driven to the retracted position.

20. The syringe of any of claims 1 to 19, wherein the plunger unit further comprises a sealing member for providing a seal with the body unit.

21. The syringe of claim 20, wherein sealing member is a compliant member.

22. The syringe of claim 21, wherein the sealing member is a resilient element which provides a biasing force in the direction of movement of the plunger unit, such as to require a predeterminable force to be applied to the plunger unit to cause locking of the needle to the one of the plunger members and the release of the one of the plunger members to retract the needle into the body unit.

23. The syringe of any of claims 1 to 19, wherein the plunger unit comprises a resilient element which provides a biasing force in the direction of movement of the plunger unit, such as to require a predeterminable force to be applied to the plunger unit to cause locking of the needle to the one of the plunger members and the release of the one of the plunger members to retract the needle into the body unit.

24. The syringe of any of claims 1 to 19, further comprising: a resilient element which provides a biasing force in the direction of movement of the plunger unit, such as to require a predeterminable force to be applied to the plunger unit to cause locking of the needle to the one of the plunger members and the release of the one of the plunger members to retract the needle into the body unit.

25. The syringe of any of claims 1 to 24, wherein the retention member is configured such as to be manually released by a user.

26. The syringe of any of claims 1 to 24, wherein the retention member is configured such as to be automatically released when the plunger unit is depressed beyond a predeterminable position in the body unit

27. The syringe of any of claims 1 to 26, further comprising: a needle, where fitted or fittable to the body unit.

28. A safety syringe, comprising: a body unit to which a needle is in use fitted; and a plunger unit which is movably disposed to the body unit, wherein the plunger unit includes a locking member which is lockable to the needle, such as to allow the needle to be retracted into the body unit.

29. The syringe of claim 28, wherein the locking member is configured such as to lock to the needle when the plunger unit is depressed beyond a predeterminable position in the body unit.

30. The syringe of claim 28 or 29, wherein the plunger unit comprises first and second plunger members which are movable relative to one another between a first, operative configuration and a second, retracted inoperative configuration in which the needle is retracted into the body unit.

31. The syringe of claim 30, wherein one of the plunger members includes the locking member and is operative to be retracted to a retracted position.

32. The syringe of claim 31, wherein the plunger unit further comprises a biasing element for rearwardly biasing the one of the plunger members to the retracted position.

33. The syringe of claim 32, further comprising: a retention member for normally retaining the plunger members in the operative configuration and being operative to release the one of the plunger members such as to be driven to the retracted position under the bias of the biasing element.

34. The syringe of claim 33, wherein the retention member is configured such as to be manually released by a user.

35. The syringe of claim 33, wherein the retention member is configured such as to be automatically released when the plunger unit is depressed beyond a predeterminable position in the body unit.

36. The syringe of any of claims 28 to 35, further comprising: a needle, where fitted or fittable to the body unit.

37. An adapter for a delivery device, the adapter comprising: a body member which is fluidly connected to an outlet of the delivery device; a needle locking member to which a needle is locked in normal use; and a needle housing member into which the needle can be retracted.

38. The adapter of claim 37, wherein needle locking member includes a locking detent for engaging the needle such as to lock the needle thereto.

39. The adapter of claim 38, wherein the needle locking member includes a release mechanism for releasing the needle from the locking detent.

40. The adapter of claim 39, wherein the release mechanism is manually operable.

41. The adapter of claim 39 or 40, further comprising: a biasing element for biasing the needle in a direction to retract the same into the needle housing member, such that, on releasing the needle from the locking detent, the needle is retracted into the needle housing member.

42. The adapter of any of claims 37 to 41, wherein the needle comprises a needle element and a coupling member which is disposed to a rear end of the needle element, by which the needle is locked to the needle locking member.

43. The adapter of claim 42, wherein the coupling member includes a bore which is fluidly connected to the needle element and provides for fluid communication with the body member when the needle is in the extended, operative position.

44. The adapter of any of claims 37 to 43, further comprising : a needle, where fitted or fittable to the body unit.

45. The adapter of any of claims 37 to 44, wherein the delivery device comprises a syringe.