PROTECTIVE SYRINGE SHEATH

Abstract: A protective sheath (12) for use with a syringe (10) having a breakable body (11) of a predetermined maximum exterior dimension. The syringe (10) includes an injection means (15) at one end of the body and a gripping means (13) at the other end of the body. The sheath (12) is characterized by a generally hollow body portion (30) which surrounds the syringe (10) but maintains a constant gap between the breakable body (11) and the interior of the sheath (12). The ends of the sheath (12) are dimensioned so as to establish contact with the syringe adjacent to the injection means (15) and the gripping means (13). When the sheath (12) and syringe (10) are assembled, the sheath is not in contact with the breakable body (11) and the end contact points serve to prevent shocks to the body (11).

Description: PROTECTIVE SYRINGE SHEATH BACKGROUND OF THE INVENTION The present invention relates generally to a protective sheath for use with an injection syringe having a potentially breakable syringe body. The invention relates more specifically to protecting a prefilled syringe body of tubular glass . The present invention relates most specifically to a breakable prefilled syringe body that is one element of a drug delivery system used for self injection by hemophiliacs. Prefilled syringes of the type which are contemplated for use in the preferred embodiment of the present invention are known in the prior art as exemplified by U.S. Patent 5,067,947, which is herein as if fully set forth. It is an object of the present invention to provide a protective sheath which surrounds the breakable syringe body and protects it against shock and breakage. SUMMARY OF THE INVENTION The present invention concerns a protective sheath for use with a syringe having a breakable body of a predetermined maximum exterior dimension. The syringe includes an injection means at one end of the body and a gripping means at the other end of the body. The sheath is characterized by a generally hollow body portion which surrounds the syringe but maintains a constant gap between the breakable body and the interior of the sheath. The ends of the sheath are dimensions so as to establish contact with the syringe adjacent to the injection means and the gripping means. When the sheath and syringe are assembled, the sheath is not in contact with the breakable body and the end contact points serve to prevent shocks to the body. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates the structural components of a syringe that will benefit from the present invention. Figure 2 illustrates a syringe having the preferred construction for use in connection with the present invention. Figure 3 is a preferred embodiment of a sheath in accordance with the invention. Figure 4 is an isolated view of the top segment of the sheath of Figure 3 taken in the direction of the arrows to the line 4-4. Figure 5 shows a portion of the sheath of Figure 3 taken along the arrowed line 5-5. Figure 6 shows an assembly of the syringe from Figure 2 with the sheath of Figure 3 in the unarmed position. Figure 7 shows the syringe and sheath combination of Figure 6 in the armed position. Figure 8 is a plan view of the sheath body of Figure 3. Figure 9 is a sectional view taken in the direction of the line 9-9 of Figure 8. Figure 10 is a section through an assembled syringe and sheath. Figure 11 is another preferred embodiment of a sheath in accordance with the invention. Figure 12 is a sectional view taken in the direction of the line 12-12 of Figure 11. DESCRIPTION OF PREFERRED EMBODIMENTS Preferred embodiments of the invention will be described with reference to the drawing figures wherein like numerals identify like elements. A breakable syringe which will benefit from the present invention is shown, in section, in Figure 1. The syringe 10 includes a glass vial or cartridge body 11 which has a finger grip 13 mounted on one end and a hub 15 for mounting a needle 17 on the other end. Typically, the needle 17 will have a needle shield 19. Alternatively, the hub 15 might include a Luer cap and Luer lock connection. The end of the vial 11 having the hub 15 is sealed prior to use. The contents 25 are retained in the vial 11 by a plunger tip 27 which effectively seals that end of the vial 11. The plunger tip 27 has female threads 29 for engagement with the male threads 23 of the plunger rod 21. The finger grip 13 is slidably mounted onto the tube 11 by a base 31 which terminates in a ring 32 that limits movement of the finger grip 13 along the vial 11. At the other end of the vial 11, the needle hub means 15, which mounts the needle 17, has a larger skirt 33 which surrounds the vial 11. The vial engaging portion 35 of hub 15 is sized to engage the metal cap 37 which secures the end seal to the vial 11. Syringes of this type are available from Schott Pharmaceutical Package, Inc., of Cleona, PA 17042. As shown in Figure 2, without the plunger rod 21, the tubular glass body of vial 11 has the hub 15 at the proximal end thereof and the finger grip 13 at the distal end thereof. As noted, the hub 15 is dimensioned to pass over and surround the proximal end of vial and forms a circumferential ridge 20 around it. The finger grip 13 passes over and surrounds the distal end of the vial 11 to provide a control means and to define an aperture for the plunger rod 21. As shown here, the finger grip 13 also includes recessed notches 22 on each side thereof. The purpose of the notches 22 will be explained in more detail hereinafter. Turning to Figure 3, the sheath 12 generally parallels the shape of the syringe 10 and has a body portion 30 with an interior volume larger than the exterior volume of the vial 11. The body portion 30 is preferably of a clear, non- breakable, injection moldable material. The proximal end of the body portion 30 includes the deflectable snap locks 34 which include cam activated projections 36. The projections 36 of snap locks 34 are located to be positioned over the circumferential ridge 20 of the hub 15 and retain syringe 10 within the proximal end of the sheath 12. See Figure 9. The proximal end of the sheath 12 also includes the truncated cone 38 which supports the reduced diameter cylinder 40. Within the cylinder 40, which terminates in a flat base 42, is the octagonal aperture 44. See Figure 5. The non- circular aperture 44 has been found to be beneficial when rotating type connections are used with the cannula end of the hub 15. In this form, the hub 15 includes a similar hexagonal exterior or fins which will interfere with its rotation within the aperture 44. This locks the hub 15 against movement and permits the use of a rotating connection, such as a Luer lock type connection. Still with reference to Figure 3, the distal end of this embodiment of sheath 12 includes the outwardly flared portion 50 that joins with the flanges 52 and the upwardly extending side walls 54. The side walls 54 include the snap locks 56. The side walls 54 are not coterminous with the flanges 52, but are blended into the flanges 52 by the arcuate portions 58. With reference to Figure 4, it can be seen that the interior volume of the distal portion above connection portion 50 has been enlarged so that the finger grip portion 13 will be received freely within the side walls 54. Use and operation of the syringe 10 with this embodiment of the sheath 12 will be more fully understood with reference to Figures 6 through 10. As shown in Figure 6, the syringe 10 is initially inserted within the sheath 12 such that the vial 11 is not in contact with the interior of the body portion 30 of sheath 12. The sides of hub 15 will contact the projections 36 of snap locks 34 and provide an initial tension to retain the syringe 10 in the sheath 12. Alternatively, the hub can be maintained in position by means of attachment to external devices. In addition, the projections 60 of the snap locks 56 will assure initial contact with the exterior of the finger grip 13 below the notches 22. In this initial insertion position, the syringe has not been activated and this may be visually determined by looking at the relative position of the projections of finger grip 13 with respect to the flanges 52 of the sheath 12. The gap therebetween is visible and provides an indicator that the syringe has not been activated. Inward progression of the syringe 10 results in deflection of the snap locks 34 and 56 as the syringe move inwardly. When the syringe progresses in sufficiently to move the hub 15 in to contact with the interior surface at 42, the cam portion of projections 36 will clear the circumferential ridge 20 of hub 15 and the inward force of snap locks 34 will bring the flat lands of the projections 36 into position over the circumferential ridge 20. Likewise, the deflection of snap locks 56 causes outward movement of the projections 60 until they pass the finger grip 13 and the projections 60 rebound inwardly to bring the flat lands thereof into the notches 22 in the finger grip 13. This condition is shown in Figure 7. The condition illustrated in Figure 7 provides two visual means for confirming that the syringe has been armed. In the first instance, the gap between finger grips 13 and flanges 52 is closed and the finger grip 13 is nested within the flanges 52. The upwardly extending side walls 54 of the flanges 52 are not needed to arm the syringe, however, they confirm complete arming by obscuring any visible air gap between the two flanges which may result from the stack-up of manufacturing tolerances. The second visual means to confirm arming is provided by the visually detectable increase in the amount of vertical wall 54 extending above the finger grip 13. In the initial position of Figure 6, the walls 54 are only of sufficient height to prevent accidental arming and to permit the snap locks 56 to be in contact with the finger grip 13. As shown in Figure 7, the walls 54 extend substantially above the finger grip 13 and provide additional protection against shock. With reference to Figures 11 and 12, there is shown a preferred embodiment of the present invention which includes the additional projections 60. The sheath 112 has a body 130 which generally corresponds to all of the features previously described. In this embodiment, the vertical walls 154 extend further above the finger grip 113 to permit elongation of the snap locks 156. As shown in Figure 12, this elongation of the snap locks 156 permits the addition of projections 160. The snap locks 156 continue to have the projections 60. Through the use of this embodiment, it is possible to insert the syringe 10 into the sheath 112 so that the finger grip 13 will be positioned in the gaps 162 between the projections 60 and 160. By so locating the finger grip 13, the projections 160 will prevent accidental withdrawal of the syringe 10 from the sheath 112 and will avoid the potential for accidental contamination. In all other respects, the sheath 112 of this embodiment will function as previously described with respect to Figures 6 through 10. It will be appreciated by those skilled in the art that the resiliency of the snap locks 34, 56 and 156 will provide a cushioning effect, will allow some movement of syringe 10 within the sheath 12, and will prevent the transmission of a breaking force impact to the syringe 10. In combination with the air gap 70 between the bodies 11 and 30, shown in Figure 10, these features allow controlled movement of the syringe 10 within the sheaths 12 and 112.

Claims: What is claimed is: 1. A protective sheath for use with a syringe of a type having a breakable body of a predetermined dimension extending between an injection end and a gripping end, the sheath characterized by: a hollow body having a generally closed proximal end and a generally open distal end; the distal end is dimensioned to engage the gripping end of the syringe; the proximal end is dimensioned to engage the injection end; and the hollow body is dimensioned to define a gap between it and the syringe body. 2. The protective sheath of claim 1 wherein: the distal end includes resilient means that engage the gripping end. 3. The protective sheath of claim 2 wherein: each resilient means includes at least one projection that extends over the gripping end. 4. The protective sheath of claim 2 wherein: each resilient means includes at least two projections that extend over the gripping end. 5. The protective sheath of claim 4 wherein: the projections are space apart by a distance sufficient to permit location of the griping between them.

Inventors: BENYA SHARON M, DE FOGGI JOHN MARK, DI MEO JOSEPH D, KARIM SYED, PELLOW JOHN W, BENYA, SHARON, M., DE FOGGI, JOHN, MARK, DI MEO, JOSEPH, D., KARIM, SYED, PELLOW, JOHN, W.
Applicants: BENYA SHARON M, FOGGI JOHN MARK DE, KARIM SYED, MEO JOSEPH D DI, PELLOW JOHN W, SCHOTT PHARMACEUTICAL PACKAGIN, BENYA, SHARON, M., DE FOGGI, JOHN, MARK, DI MEO, JOSEPH, D., KARIM, SYED, PELLOW, JOHN, W., SCHOTT PHARMACEUTICAL PACKAGING, INC.
Application year: 1999
Main classification: A61M5
IPC codes: A61M5