NEEDLE ASSEMBLY

Abstract: A needle assembly (10) includes a housing (12), a needle (14) projecting from the housing (12), a needle shield (16) displaceable relative to the needle (14) to vary the length of an unshielded portion of the needle (14) projecting from the needle shield (16) and locking means (48) for locking the needle shield (16) in a position in which the point (34) of the needle (14) is shielded by the needle shield (16).

Description: NEEDLE ASSEMBLY FIELD OF THE INVENTION This invention relates to a needle assembly. SUMMARY OF THE INVENTION According to the invention a needle assembly includes: a housing; a needle projecting from the housing; a needle shield displaceable relative to the needle to vary the length of an unshielded portion of the needle projecting from the needle shield; and locking means for locking the needle shield in a position in which the point of the needle is shielded by the needle shield. The locking means may be non-releasably lockable to lock the needle shield in a disposal position when it is desired to dispose of the needle assembly. The locking means may also be releasably lockable to lock the needle shield in unshielded positions in which the needle projects from the shield and in a storage position in which the needle is shielded by the shield. The locking means may include at least one locking formation on the needle shield which can engage with a locking formation on the housing to lock the needle shield in position. The locking formation on the needle shield may be resiliently flexible. The locking means may be releasably lockable by way of a friction lock for frictionally locking the needle shield to the housing to facilitate location of the needle shield in a desired unshielded position or in the storage position. The friction lock may be provided by abutment of the locking formation of the needle shield against the housing, so that as the needle shield is displaced relative to the housing, the resiliently flexible locking member generates friction between itself and the housing. The needle shield is preferably slidably secured to the housing by a slide and slideway arrangement. The needle projecting from the housing may be offset relative to the central axis of the housing to facilitate intravenous insertion of the needle into a patient at an angle which is acutely tangential to or contiguously co-planar with the skin surface of a patient. Preferably the needle is a cranked needle, with a cranked or radially extending portion of the needle extending between the portion of the needle projecting from the housing and a portion of the needle projecting into the housing. Part of the needle projecting into the housing may be covered with a teat, the teat having a bore with a neck which, by virtue of an interference fit between the neck and the needle, forms a seal between the neck and the needle, the remainder of the bore of the teat being a loose fit on the needle so that the teat can be displaced along the needle by a fluid collection vial. The scope of the invention extends separately to the teat, to the housing, to the needle slide and to the needle. According to another aspect of the invention a needle assembly includes: a housing; a carriage displaceable relative to the housing; and a needle engaged with the carriage so that the length of the needle projecting from the housing can be varied by displacing the carriage relative to the housing. The housing preferably has a needle guide into which the point of the needle can be withdrawn by the carriage to render the needle assembly needle-stick safe. The needle assembly may be a phlebotomy needle assembly. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an under plan view of the needle assembly; Figure 2 is a cross-sectional view on line II - II of figure 1 ; Figure 3 is a cross-sectional plan view of the needle assembly; Figure 4 is a cross-sectional end view on line IV - IV of figure 3; Figure 5 is a cross-sectional side view of the needle assembly with its needle shield in its storage position; Figure 6 is a cross-sectional end view through the wings of the needle shield in its position shown in figure 5; Figure 7 is a cross-sectional side view of the needle shield in its unshielded fully retracted position; Figure 8 is a cross-sectional end view through the wings of the needle shield in its position shown in figure 7 relative to the barrel of figure 5; Figure 9 is a cross-sectional side view of the needle shield in an intermediate unshielded position; Figure 10 is a cross-sectional end view through the wings of the needle shield in its position shown in figure 9 relative to the barrel of figure 5; Figure 11 is a cross-sectional side view of the needle shield in its disposal position; Figure 12 is a cross-sectional end view through the wings of the needle shield in its position shown in figure 11 relative to the barrel of figure 5; Figure 13 is a cross-sectional view on lines N-N of figure 5 showing the needle clips; Figure 14 is a plan view of the needle shield; Figure 15 is a bottom view of the needle shield; Figure 16 is a side view of the needle shield; Figures 17 to 29 are cross-sectional end views of the needle shield along the lines indicated in figure 16; Figures 30 to 35 are cross-sectional side views showing how the needle assembly is assembled; Figures 36 - 39 are cross-sectional side views of parts of alternative needle assemblies; Figure 40 is a cross-sectional schematic end view of an alternative embodiment of the needle assembly; Figure 41 is a schematic plan view of the needle shield of figure 40 showing its interaction with a slideway of the barrel; Figure 42 is a cross-sectional side view of an alternative embodiment of the needle assembly; Figure 43 is a cross-sectional schematic side view of a further alternative embodiment of the needle assembly; and Figure 44 is an end view of the needle assembly of figure 43. DETAILED DESCRIPTION OF THE DRAWINGS Referring firstly to figures 1 to 29, a phlebotomy needle assembly 10 includes a housing in the form of a barrel 12, a needle 14 and a needle shield 16. The barrel 12 is injection moulded from polypropylene and has a slideway 18 for the needle shield 16. The barrel 12 is closed at its front end by way of a bulkhead 22 and has an opening 24 at its rear end. The bulkhead 22 has a forwardly extending projection or tongue 26. The needle 14 is cranked and consists of an exterior portion 28, a cranked or radially extending portion 30 and an interior portion 32. The exterior portion 28 terminates in a point 34, and likewise the interior portion 32 terminates in a point 36. The cranked portion 30 of the needle 14 is held within clips 38 against the bulkhead 22. Part of the interior portion 32 of the needle 14 abuts a projection 40 extending rearwardly from the bulkhead 22. The projection 40 contains a groove 42 with a flared opening 44 for locating the needle 14 in position. The needle shield 16 is injection moulded from polyacetal using a two piece mould. The needle shield has a thumb grip 46, two locking formations or wings 48, a slide 50.1 to 50.3, and grooves 52.1 to 52.3 for the needle 14. It can be seen from figures 14 to 29 that the grooves 52.1 to 52.3 for the needle 14 are discontinuous. Likewise the slide 50.1 to 50.3 is discontinuous. The needle shield 16 can be slid between a storage position as shown in figure 5 and an unshielded fully retracted position as shown in figure 7. The position of the needle shield 16 is infinitely variable between the storage and unshielded fully retracted positions. One such intermediate position is shown in figure 9. In the storage position the point 34 of the needle is shielded by the needle shield 16. As the needle shield 16 is retracted from the storage position, so the length of the unshielded portion of the needle increases. The length of the unshielded portion of the needle can thus be set to a desired length to suit a particular patient. The groove 52.3 of the needle shield 16 contains a raised zone 54 which abuts a bend 56 in the needle when the needle shield 16 is in its storage position as shown in figure 5 This is to prevent the needle shield 16 from accidentally being pushed beyond its storage position to a disposal position which is shown in figure 11 Between the unshielded fully retracted position and the storage position the locking wings 48, which are resiliency flexible, abut the barrel 12 or its tongue 26 creating a friction lock between the needle shield and the barrel or its tongue 26 This friction lock ensures that when the needle shield is set in a desired position, it will remain in that position until sufficient force is applied to the needle shield to overcome the friction lock In the disposal position the locking wings 48 are pushed beyond a tip 57 of the tongue 26 This enables the locking wings 48 to move upwardly as shown in figure 12 and abut against the tip 57 of the tongue 26 The needle shield cannot be retracted from this position without depressing or breaking the locking wings 48 The needle shield is thus for practical purposes non- releasably locked in the disposal position As in the storage position, the point 34 of the needle 14 is shielded by the needle shield when the needle shield is in its disposal position The needle assembly 10 can thus be disposed of with the needle shield in its disposal position without fear of someone being pricked by the point 34 of the needle 14 Referring now to figures 30 to 35, the steps involved in assembly the needle assembly are illustrated In figure 30 the needle 14 is slid into its slide by depressing the locking wings 48 In figure 31 the needle 14 with a teat 58 in position is inserted into the needle shield The needle shield 16 and the tongue 26 are bent as shown in figure 32, and the needle is pushed into the needle shield until its seats in the needle shield as shown in figure 33 The needle 14 is then pushed forward and clipped into the clips 38 on the bulkhead 22 as shown in figure 34 The needle shield is then slid forward to its storage or purchase position as shown in figure 35. The rubber teat 58 has a flared opening 60 to a bore which has a neck 62. The neck 62 has a narrower diameter than the remainder of the bore. The diameter of the neck 62 is less than the diameter of the needle, and the diameter of the remainder of the bore is greater than the diameter of the needle. The neck is thus an interference fit on the needle, and by virtue of the interference fit, forms a seal between the remainder of the bore and the neck. The seal prevents blood from escaping from the teat when the needle is inserted into a patient. A blood collection vacuum vial (not shown) is inserted into the barrel to collect blood in a known manner. Referring now to figure 36 in a needle arrangement 10.1 the cranked portion 30 of the needle 14 is located outside the barrel, and a teat 58.2 is inserted from the front of the bulkhead 22 and constricted within the projection 40 to form a seal between the teat and the needle. External needle clips 38A defined on the front face of the bulkhead 22 hold the cranked portion 30 of the needle 14 in a similar manner to the internal needle clips of figure 5. In figure 37 a needle assembly 10.2 is the same as that shown in figure 5 except that the bulkhead 22.1 of the barrel is clipped in place. From figure 38 it can be seen that a needle assembly 10.3 is the same as that shown in figure 36 except that the bulkhead 22.2 of the barrel is clipped in place. In figure 39, a needle assembly 10.4 is similar to that shown in figure 37 except that the teat 58.2 is located over a barb 59 to form a seal. In figures 40 and 41 , a needle assembly 10.5 is shown having a barrel 12.1 with a slideway 18.1 along which a needle shield 16.1 slides. The needle shield 16.1 has a slot 63 within which the slideway 18.1 locates. The needle shield is made of polyacetal which is resiliently flexible. The slot has four positions A to D in which the needle shield 16.1 can be releasably locked relative to the slideway 18.1 , and one position E in which it is non-releasably locked to the slideway 18.1. The left hand position E of the slideway 18.1 is the disposal position of the needle assembly, the intermediate position A of the slideway is the storage position of the needle assembly, and the right hand position D of the slideway is the position in which the needle has its maximum unshielded length. Between the intermediate position A and the right hand position D of the slideway, there are two other positions B and C which enable a practitioner discretionally to vary the unshielded length of the needle to suit the patient concerned. Referring now to figure 42 a needle assembly 10.6 has a needle shield 16.2 with a thumb grip 65. A lug 64 extends from the thumb grip 62. The lug 64 abuts the barrel 12.2 and can be slid along the barrel 12.2 creating a friction lock between the needle shield and the barrel. The barrel has a recess 66 with tapered sides in which the lug releasably locates when the needle shield is in its storage position. The barrel also has a recess 68 with a vertical side in which the lug 64 non-releasably locks when the needle shield is in its disposal position. In figure 42 the left hand position of the thumb grip depicts the needle shield in its disposal position and the right hand position of the thumb grip depicts the needle shield in an unshielded partly retracted position. Referring finally to figures 43 and 44, a needle assembly 10.7 has a housing or barrel 12.3 with a needle guide 70 projecting from the front thereof. A needle carriage 72 is slidably secured to the barrel 12.3. A cranked needle 14 is secured to the needle carriage 72 and a teat 58 is located over a rear portion of the cranked needle. The needle carriage 72 can be slid between an extended position (needle carriage shown in solid lines) in which the length of the needle projecting from the needle guide is at its maximum, and a retracted or storage position (needle carriage shown in dotted lines) in which the point 34 of the needle 14 is located within the needle guide 70. The needle carriage 72 can be located in any position between its extended and retracted positions to set the length of the needle projecting from the needle guide to a desired length. As with the other embodiments of the needle assemblies described above, the needle carriage has a disposal position located rearwardly of the storage position in which the needle carriage can be non-releasably locked for disposal purposes. It will be appreciated that many modifications or variations of the invention are possible without departing from the spirit or scope of the invention.

Claims: CLAIMS: 1. A needle assembly including: a housing; a needle projecting from the housing; a needle shield displaceable relative to the needle to vary the length of an unshielded portion of the needle projecting from the needle shield; and locking means for locking the needle shield in a position in which the point of the needle is shielded by the needle shield. 2. The needle assembly of claim 1 wherein the locking means is non- releasably lockable to lock the needle shield in a disposal position when it is desired to dispose of the needle assembly. 3. The needle assembly of claim 1 or claim 2 wherein the locking means is releasably lockable to lock the needle shield in unshielded positions in which the needle projects from the shield and releasably lockable in a storage position in which the needle is shielded by the shield. 4. The needle assembly of any of the above claims wherein the locking means includes at least one locking formation on the needle shield which can engage with a locking formation on the housing to lock the needle shield in position. 5. The needle assembly of claim 4 wherein the locking formation on the needle shield is resiliently flexible. 6. The needle assembly of any of claims 3 to 5 wherein the locking means is releasably lockable by way of a friction lock for frictionally locking the needle shield to the housing to facilitate location of the needle shield in a desired unshielded position or in the storage position. 7. The needle assembly of claim 6 insofar as it is dependent on claim 4 or claim 5 wherein the friction lock is provided by abutment of the locking formation of the needle shield against the housing, so that as the needle shield is displaced relative to the housing, the resiliently flexible locking member generates friction between itself and the housing. 8. The needle assembly of any of the above claims wherein the needle shield is slidably secured to the housing by a slide and slideway arrangement. 9. The needle assembly of any of the above claims wherein the needle projecting from the housing is offset relative to the central axis of the housing to facilitate intravenous insertion of the needle into a patient at an angle which is acutely tangential to or contiguously co-planar with the skin surface of a patient. 10. The needle assembly of claim 9 wherein the needle is a cranked needle, with a cranked or radially extending portion of the needle extending between the portion of the needle projecting from the housing and a portion of the needle projecting into the housing. 11. The needle assembly of claim 10 wherein the portion of the needle projecting into the housing is covered with a teat, the teat having a bore with a neck which neck forms a seal between itself and the needle, with at least part of the remainder of the bore of the teat being a loose fit on the needle so that the teat can be displaced along the needle by a fluid collection vial. 12. A needle assembly including: a housing; a carriage displaceable relative to the housing; and a needle engaged with the carriage so that the length of the needle projecting from the housing can be varied by displacing the carriage relative to the housing. 13. The needle assembly of claim 12 wherein the housing has a needle guide into which the point of the needle can be withdrawn by the carriage to render the needle assembly needle-stick safe. 14. A needle assembly including a housing, a needle associated with the housing with at least part of the needle projecting into the housing, and a teat covering at least part of the needle projecting into the housing, the teat having a bore and a neck with the neck being an interference fit between itself and the needle to form a seal between the neck and the needle, and at least part of the remainder of the teat being a loose fit on the needle so that the teat can be displaced along the needle by a fluid collection vial. 15. A needle assembly substantially as herein described and illustrated with reference to the accompanying drawings.

Inventors: BULL ANTHONY ERIC, DUGMORE PETER BALFOUR, REYNOLDS STANFORD WILLIAM GLAD, BULL, ANTHONY, ERIC, DUGMORE, PETER, BALFOUR, REYNOLDS, STANFORD, WILLIAM, GLADWIN
Applicants: BULL ANTHONY ERIC, DUGMORE PETER BALFOUR, REYNOLDS STANFORD WILLIAM GLAD, BULL, ANTHONY, ERIC, DUGMORE, PETER, BALFOUR, REYNOLDS, STANFORD, WILLIAM, GLADWIN
Application year: 2000
Main classification: A61M5
IPC codes: A61M5