GB2517024A

GB2517024A - Syringes

Info

Publication number: GB2517024A
Application number: GB201408677A
Authority: GB
Inventors: Roger Tyler; Darren Collett-Mills
Original assignee: PRO SURGICAL Ltd
Current assignee: PRO SURGICAL Ltd
Priority date: 2013-05-15
Filing date: 2014-05-15
Publication date: 2015-02-11
Also published as: GB201408677D0; GB201308716D0; WO2014184321A2; WO2014184321A3

Abstract

A syringe for drug injection from a cartridge 26 has a hand-andÂ-thumb operated plunger 4 that slides through a finger-hold 3 into a tubular body 1 which is attached to the finger-hold 3 by a bayonet connection between pins on the finger-hold 3 and L-shape slots on the tubular body 1. The bayonet connection is established by twisting the body 1 relative to the finger-hold 3 and this also engages tags on body 1 in slots on finger-hold 3 to enhance the attachment. A needle-guard sleeve 12 slides on the tubular body 1 between a retracted allowing needle attachment, and a pre-use condition in which the needle 32 is shielded. After injection the sleeve 12 is pushed further forward over the needle 32 into a post use condition, from which return to the earlier conditions is blocked.

Description

Syringes S This invention relates to syringes.

According to the present invention there is provided a syringe in which a plunger is slidable through a finger-hold into a body of the syringe for actuation of the syringe, wherein attachment of the body and finger-hold to one another is via a bayonet connection.

The finger-hold of the syringe of the invention may be a finger-grip of the syringe having lateral projections for gripping by fingers of the user's hand while pressure is exerted on the plunger for actua:ion of the syringe by the thuiro or palm of the hand. As an alternative, the finger-hold may be a part of the syringe that has apertures into which fingers of the user's hand are inserted while the actuation pressure is being exerted on the nlunger. The plunger may have a head formed as a T-bar, and in particular the head may be formed as a combined T-bar and thumb-hold.

The body of the syringe tray be of an elongate tubular form and may have a proximal end with iametrically-oppo5ed L-shape slots therein, the bayonet connection being in these circumstances established by engagement within the L-shape slots of pins that project from the finger-hold. The attachment of the body arid finger-hold to one another may include in addition to the bayonet connection, engagement of 0metrica1ly-opposed tags at the proximal end of the body of the syringe with slots of the finger-hold. Engagement of the pins that project from the finger-hold with the L-shape slots1 and of the tags with the slots of the finger-hold, may be effected under twisting of the body of the 36 syringe and the finger-hold relative to one another-A syringe according to the present invention will now be described by way of example with reference to the accompanying drawings, in which:

S

Figures 1 and 2 are respectively a sectional elevation and a perspective view of the syringe according to the invention; Figure 3 is an exploded view of the syringe of Figures 1 and 2; Finure 4 is a perspective view of a body component of the syringe of the invention; Figures 5 and 6 are respectively a side elevation and an underneath plan of a finger-grip component of the syringe of the invention; Figure 7 is a perspective view of a needle-guard sleeve of the syringe of the invention; Fioures 8 and 9 are respectively an exploded sectional elevation and an exploded perspective view of the syringe of the invention when fitted with a needle unit and including a cartridge containing a drug to be injected; Figures 10 and 11 are respectively a sectional elevation and a perspective view of the syringe of the invention prepared for administering an injection; and Figures 12 and 13 are respectively a sectional elevation and a perspective view of the syringe of the invention after the injection has been a&rinistered.

The syringe to be described is a disposable syringe for adnnistering an anaesthetic or other drug from a cartridge. It js especially for use in dental applications, but may be used with advantage in applications other than this, and although it is of a font that lends itself to single-use may in large part be used repeatedly -Referring to Figures 1 to 3, the syringe has a tubular body 1 which is attached securely at its proximal end 2 (see Figure 3) to a finger-grip 3. A plunger 4 having a head 5 formed as a combined T-bar and thumb-hold, is slidable through the finger-grip 3 to project into the body 1 through a tubular projection 6 (Figure 3) from the base 7 of the finger-grip 3. t'}fl the head 5 is closed onto the finger-grip 3 (the condition shown in Figures 1 and 2), the plunger 4 projects to its full extent into the body 1 which is required in use of the syringe to complete dispensing from a cartridge (not shown) of an appropriate injection-drug through a hollow hypodermic needle (not shown) secured to the distal end S of the body 1. A resilient sealing ring 9 which is trapped in a circumferential groove 10 at the distal end 11 of the plunger 4 blocks withdrawal of the plunger 4 from the finger-grip 3 and guides the plunger 4 into the cartridge in the dispensing operation.

A needle-guard sleeve 12 is retained on the body 1 for sliding along the body 1 between a retracted condition (as shown in Figures 1 and 2) in which it has been drawn towards the proximal end 2 to he clear of the needle at the distal end B, to one or other of two deployed conditions in both of which it projects beyond the distal end B to shield the needle. Holding of the sleeve 12 between finger and t:miitt in sliding it between the retracted and deployed conditions is facilitated by circumferential ridges 13 moulded into the outer surface of the sleeve 12 adjacent its distal end 14.

The tubular body 1 i.s securely attached to the base 7 of the finger-grip 3 by means of a bayonet connection. In this regard, and referring to Figure 4, two diametrically-opposed L-shape slots and two diametrically-opposed outwardly-extending tags 16 are provided at the proximal end 2 of the tubular body 1, and, with reference now also to Figures 5 and 6, assembly of the syringe involves pushing the body 1 onto the base 7 of the finger-grip 3 with the tubular projection 6 entered into the end 2 and each slot 13 entered by a respective one of two diametrically-opposed pins 17 of the projection 6. The body I is pushed fully onto the finger-grip 3 to enter the pins 17 to the full depth of the slots 15, and is then twisted relative to the finger-grip 3 to establish tho bayonet connection fuly with the pins 17 at the ends of the slots 15. This twisting also moves the tags 16 at the end 2 of the body I into slots 18 under two lugs 19 that project from the base 7 either side of the projection 6. Ent' of the tags 16 in the slots 18 further enhances the security with which the body 1 is firmly attached to the finger-grip 3 by the bayonet connection.

Once the tubular body 1 has been secured to the finger-grip 3, the needle-guard sleeve 12 with its proximal end 14 leading is pushed onto the body 1 from the distal end 8 of the body 1. As shown most clearly in Figure 7, the proximal end 14 of the sleeve 12 has a circumferential ridge 21 and is slotted lengthwise to give it a degree of resilience which enables the end 14 to latch between the inwardly-bulging free-ends 20 of the lugs 19. This latching of the end 14 between the lugs 19 retains the sleeve 12 resiliently in the retracted condition on the body 1.

With further reference to Figures 3 and 4, the resilience of the proximal end 14 of the needle-guard sleeve 12 is also effective fcr retention of the sleeve 12 in each of two deployed conditions, a first pre-use condition and a second post-use' condition, in both of which the needle is shielded. In the pre-use deployed-condition the sleeve 1:2 is extended beyond the distal end B of the body 1 to a lesser extent than in the post-use deployed_cOnditiont and involves a circumferential groove 22 into which the proximal end 14 of the sleeve 12 latches resiliently arid from which the sleeve 12 can be readily pulled back to the retracted condition.

On the other hand, the post-use deployed-condition involves a circumferential groove 23 which is closer to the distal end 8 than S the groove 22, and a pair of diametrically-Opposite tags 24 located between the two grooves 22 and 23. Each tag 24 is sprung-up resiliently so as to enable the distal end 14 of the sleeve 12 to pass from the groove 22 over them to latch resiliently in the groove 23, but to bck return of the distal end 14 over them.

(The tags 24 are depressed manually during assently of the syringe in order to allow the distal end 14 of the sleeve 12 to be pushed over them.) Referring to Figures 8 arid 9, the syringe is prepared for use by fitting a needle unit 25 to the distal end 8 of the body 1 and, whether this is carried out before or after the needle unit 25 is fitted, the tubular body 1 is detached from the finger-grip 3 and a cartridge 26 containing the drug required for injection, is inserted into the tubular body 1; insertion of the cartridge 26 is with an orientation (as illustrated) in which its end having a diaphragm-seal 27 is leading and its opposite end, which is closed by a slidable plug 28, is trailing. The fitting of the needle imit 25 is carried out with the sleeve 12 in its retracted condition and is followed iygnediate1y by sliding of the sleeve 12 into its pre-use deployed condition as shown for protection of the user against needle-stick injun'. Once the cartridge 26 has been loaded into the body 1, the handle S is withdrawn fully away from the finger-grip 3 (as illustrated in Figures 8 and 9), before the body 1 is re-attached to the finger-grip 3.

Having prepared the syringe in this way, it is brought into use by applying pressure to the handle 5 to press the distal end 11 of the plunger 4 with the ring 9 into the cartridge 26 and onto the plug 20. This pressure on the handle 5 is applied while lateral projections of the finger-grip 3 are being gripped by the user's fingers (usually the first and second fingers) , and the palm of the user's hand is applied to the shaped top 29 of the handle 5 or the user's thumb is pressed down within the aperture 30 beneath the top 29. Further pressure urges the cartridge 26 down onto the S rear-projection 31 of the hollow needle 32 of the unit 25 piercing the diaphragm-seal 27 of the cartridge 26 and by this admitting the cartridge-contained drug to the needle 32, ready for the drug to be administered by injection.

Injection is carried out by first withdrawing the sleeve 12 to its retracted condition clipped to tho finger-grip 3 as illustrated in Figures 10 and 11. This exposes the needle 32 ready for actuation of the syringe in the nonnai procedure of injection under which the contents of the cartridge 26 are administered to the patient by pressing the handle 5 down to close it onto the finger-grip 3 and thereby push the plug 28 down the cartridge 26. Once the needle 32 has been withdrawn from the injection site, the sleeve 12 is slid down the body I from the retracted condition through the pro-use deployed condition into the post-use deployed condition illustrated in Figures 12 and 13. Return of the sleeve 12 from this condition is blocked by the tags 24, leaving the needle 32 safely shielded to avoid re-use.

The described syringe, apart from the ring 9, is constructed wholly of plastics material, and in addition to the used needle-unit 25 and empty cartridge 26, can be economically discarded for safe disposal after single use. As an alternative, the handle 5 and finger-grip 3 may be retained for re-use, and for this purpose may for example be mouldings of a nylon-based material.

Furthermore, instead of providing the needle 32 as separate from the sviringe, the syringe may be provided with the needle attached.

Claims

Claims: 1. A syringe in which a plunger is slidable through a finger-hold into a body of the syringe for actuation of the syringe, wherein attachment of the body and finger-hold to one another is via a bayonet connection.
2. A syringe according to claim 1 wherein the finger-hold is a finger-grip of the syringe having lateral projections for gripping by fingers of the user's hand while pressure is exerted on the rlunger for actuation of the syringe by thuwh or palm of tho hand.
3. A syringe according to clam 1 wherein the finger-holld is a part of the syringe that has apertures into which fingers of the user's hand are inserted while pressure for actuation of the syringe is being exnrted on the plunger.
4. A syringe according to any one of claims 1 to 3 wherein the plunger has a head formed as a T-bar.
5. A syringe according to claim wherein the head of the plunger is formed as a combined T-bar and thumb-hold.
6. A syringe according to any one of claims 1 to S wherein the body of the syringe is of an elongate tubular forts and has a proximal end with diametrically-opposed L-shape slots therein, and the bayonet connection is established by engagement within the L-shape slots of pins that project from the finger-hold.
7. A syringe according to claim 6 wherein the attachment of the body and finger-hold to one another includes engagement of jmetrically-opposed tags at the proximal end of the body of the syringe with slots of the finger-hold, engagement of the pins that project from the finger-hold with the L-shape slots and of the tags with the slots of the finger-hold being effected underBtwisting of the body of the syringe and the finger-hold relative to one another.
8. A syringe according to any one of claims 1 to 7 wherein a needle-guard sleeve Is slidable along the body of the syringe between a retracted condition in which the distal end of the sleeve is retracted from the distal end of the body, and a pre-use deployed condition in which the distal end of the needle-guard sleeve projects beyond the distal end of the body.
9. A syringe according to claim 8 wherein the needle-guard sleeve when in the retracted condition latches resiliently in that condition.
10. A syringe according to claim 8 or claim 9 wherein the needle-guard sleeve when in the pre-use deployed condition latches resiliently in that condition.
11. A syringe according to any one of claims 8 to 10 wherein the needle-guard sleeve is slidable along the body of the syringe from the pre-use deployed condition to a post-use deployed condition in which the distal end of the needle-guard sleeve projects further beyond the distal end of the body of the syringe than when the needle-guard sleeve is in the pre-use deployed condition.
12. A syringe according to claim Ii wherein sliding of the needle-guard sleeve along the body in return from the post-use deployed condition to the pre-use condition is blocked.
13. A syringe according to any one of claims 8 to 12 wherein a hypodermic needle is fitted to the distal end of the body of the syringe, and the needle-guard sleeve shields the needle when the needle-guard shield is in the pre-use deployed condition and is retracted from shielding the needle when the needle-guard shield is in the retracted condition. a
14 A syringe according to claim 13 wherein the body of the syringe is tubular for receiving entry therein of a cartridge containing a drug for injection through the needle.
15. A syringe according to claim 14 wherein the needle has a rear-projection for piercing a seal of the cartridge in admitting the 0artridge-containing drug to the needle.
16. A syringe substantially as hereinbefore described with reference to the accompanying drawings.