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EP-3810232-B1 - PLUNGER ROD AND ASSEMBLY HAVING MODIFIED THREAD GEOMETRY

EP3810232B1EP 3810232 B1EP3810232 B1EP 3810232B1EP-3810232-B1

Inventors

  • THOMPSON, JAMES
  • SHAFER, LAUREN
  • SWEENEY, MATTHEW, DYLAN

Dates

Publication Date
20260506
Application Date
20190621

Claims (17)

  1. A plunger assembly (10, 210, 310, 410) for a fluid-dispensing syringe, the plunger assembly (10, 210, 310, 410) comprising: a piston (20, 220) comprising an inner piston surface (26, 226), a female thread (28, 228); and a proximal piston end (30, 230), wherein the inner piston surface (26, 226) and the female thread (28, 228) define an inner piston cavity (24, 224); and a plunger rod (50, 250, 350, 450) comprising a distal rod end (56, 256, 356, 456) and a threaded extension (58, 258, 358, 458) that extends a length distally from the distal rod end (56, 256, 356, 456), wherein: the threaded extension (58, 258, 358, 458) is configured to threadedly engage with the female thread (28, 228) along at least a portion of the length, characterized in that : the threaded extension (58, 258, 358, 458) and the inner piston surface (26, 226) define a ventilation space (82, 282, 382, 482) when the plunger rod (50, 250, 350, 450) is fully advanced distally relative to the piston (20, 220), and the proximal piston end (30, 230) and the distal rod end (56, 256, 356, 456), when the plunger rod (50, 250, 350, 450) is fully advanced distally relative to the piston (20, 220), are spaced apart and define a fluid passageway (90, 290, 390, 490) therebetween, the fluid passageway (90, 290, 390, 490) extends from outside of the plunger assembly (10, 210, 310, 410) and into the inner piston cavity (24, 224).
  2. The plunger assembly (10, 210, 310, 410) according to claim 1, wherein: the inner piston cavity (24, 224) comprises a proximal cavity end (24a, 224a) and a distal cavity end (24a, 224a), the female thread (28, 228) is spaced apart from the distal cavity end (24a, 224a), the threaded extension (58, 258, 358, 458) comprises a male thread (59, 259, 359, 459), the male thread (59, 259, 359, 459) comprising a proximal male thread end (59a) and a distal male thread end (59b), the male thread (59, 259, 359, 459) is configured so that, when the plunger rod (50, 250, 350, 450) is fully advanced distally, the proximal male thread end (59a) is located distally of the female thread (28, 228), and the ventilation space (82, 282, 382, 482) is between the threaded extension (58, 258, 358, 458) and the inner piston surface (26, 226).
  3. The plunger assembly (10, 210, 310, 410) according to claim 1, wherein: the inner piston cavity (24, 224) comprises a proximal cavity end (24a, 224a) and a distal cavity end (24a, 224a), the female thread (28, 228) is spaced apart from the distal cavity end (24a, 224a), the threaded extension (58, 258, 358, 458) comprises: a thread shank (62, 262, 362, 462) comprising a proximal thread shank end (64, 264, 364) and a distal thread shank end (66, 266, 366); and a male thread (59, 259, 359, 459) that extends from the thread shank (62, 262, 362, 462), the male thread (59, 259, 359, 459) comprising a proximal male thread end (59a) and a distal male thread end (59b), the proximal male thread end (59a) being spaced apart from the proximal thread shank end (64, 264, 364), and the ventilation space (82, 282, 382, 482) is between the threaded extension (58, 258, 358, 458) and the inner piston surface (26, 226).
  4. The plunger assembly (10, 210, 310, 410) according to claim 1, wherein: the plunger rod (50, 250, 350, 450) comprises an outer surface comprising an outer distal end surface (53a, 253a, 353a, 453a) and an outer side surface (53b 253b, 353b, 453b), and the plunger rod (50, 250, 350, 450) comprises an auxiliary passage (57, 257, 357, 457) that extends from at least one of the outer distal end surface (53a, 253a, 353a, 453a) or the outer side surface (53b 253b, 353b, 453b) and that fluidly connects to the ventilation space (82, 282, 382, 482).
  5. The plunger assembly (10, 210, 310, 410) according to claim 1, wherein: the inner piston cavity (24, 224) comprises a proximal cavity end (24a, 224a) and a distal cavity end (24a, 224a), the female thread (28, 228) comprises a plurality of female threads (28, 228), the plurality of female threads (28, 228) have a female-thread major diameter (228a) and a female-thread minor diameter (228b); the threaded extension (58, 258, 358, 458) comprises: a thread shank (62, 262, 362, 462) comprising a proximal thread shank end (64, 264, 364) and distal thread shank end (66, 266, 366), the thread shank (62, 262, 362, 462) having a non-constant diameter; and a plurality of male threads (59, 259, 359, 459) that extend from the thread shank (62, 262, 362, 462), the plurality of male threads (59, 259, 359, 459) have a constant male thread major diameter (259c), the ventilation space (82, 282, 382, 482) is between the thread shank (62, 262, 362, 462) and the female-thread minor diameter (228b).
  6. The plunger assembly (10, 210, 310, 410) according to claim 5, wherein the ventilation space (82, 282, 382, 482) comprises a plurality of spaces between the thread shank (62, 262, 362, 462) and the female-thread minor diameter (228b).
  7. The plunger assembly (10, 210, 310, 410) according to claim 6, wherein: the plunger rod (50, 250, 350, 450) comprises an outer surface comprising an outer distal end surface (53a, 253a, 353a, 453a) and an outer side surface (53b 253b, 353b, 453b), and the plunger rod (50, 250, 350, 450) comprises an auxiliary passage (57, 257, 357, 457) that extends from at least one of the outer distal end surface (53a, 253a, 353a, 453a) or the outer side surface (53b 253b, 353b, 453b) and that fluidly connects to the ventilation space (82, 282, 382, 482).
  8. The plunger assembly (310) according to claim 1, wherein: the inner piston cavity (24, 224) comprises a proximal cavity end (24a, 224a) and a distal cavity end (24a, 224a), the female thread (28, 228) comprises a plurality of female threads (28, 228), the plurality of female threads (28, 228) have a female-thread major diameter (228a) and a female-thread minor diameter (228b); the threaded extension (358) comprises: a thread shank (362) with a thread shank axis (363); and a plurality of male threads (359) that extend from the thread shank (362), the plurality of male threads (359) have a truncated portion (359d); and the ventilation space (382) is between the truncated portion (359d) and the plurality of female threads (28, 228).
  9. The plunger assembly (310) according to claim 8, wherein: the truncated portion (359d) comprises a planar cut portion of the plurality of male threads (359); and the ventilation space (382) is between the planar cut portion and the plurality of female threads (28, 228).
  10. The plunger assembly (310) according to claim 8 or claim 9, wherein: the plunger rod (350) comprises an outer surface comprising an outer distal end surface (353a,) and an outer side surface (353b), and the plunger rod (350) comprises an auxiliary passage (357) that extends from at least one of the outer distal end surface (353a) or the outer side surface (353b) to the truncated portion (359d) to connect to the ventilation space (382).
  11. The plunger assembly (310) according to claim 8, wherein: the plunger rod (350) comprises an outer surface comprising an outer distal end surface (353a) and an outer side surface (353b), and the plunger rod (350) comprises an auxiliary passage (357) that extends from the outer side surface (353b) to the truncated portion (359d).
  12. The plunger assembly (310) according to claim 10, wherein the auxiliary passage (357) extends from the outer side surface (353b) to the truncated portion (359d).
  13. The plunger assembly (410) according to claim 1, wherein: the threaded extension (458) comprises a thread shank (462) and a discontinuous male thread comprising a plurality of protruding bodies (463, 465) that extend from the thread shank (462), the plurality of protruding bodies (463, 465) comprising a plurality of radially outward portions (463a, 465a); and the ventilation space (482) is between the plurality of protruding bodies (463, 465).
  14. The plunger assembly (410) according to claim 13, wherein the plurality of protruding bodies (463, 465) comprises at least one of a hemispherical body (463) or a rod-shaped body with a hemispherical radially outward portion (465).
  15. The plunger assembly (410) according to claim 13 or claim 14, wherein the thread shank (462) has a non-constant male thread shank diameter.
  16. The plunger assembly (410) of any one of claims 13 through 15, wherein: the plunger rod (450) comprises an outer surface comprising an outer distal end surface (453a) and an outer side surface (453b), and the plunger rod (450) comprises an auxiliary passage (457) that extends from at least one of the outer distal end surface (453a) or the outer side surface (453b) and that fluidly connects to the ventilation space (482).
  17. A method of sterilizing the plunger assembly (10, 210, 310, 410) according to any one of claims 1 through 9, or 12-14, the method comprising introducing a sterilizing fluid into a space outside the plunger assembly (10, 210, 310, 410), thereby causing the sterilizing fluid to pass into the inner piston cavity (24, 224) and sterilize the inner piston cavity (24, 224).

Description

BACKGROUND This application relates to a syringe having a barrel with plunger assembly inserted therein, wherein the plunger assembly includes a piston and a plunger rod inserted therein. More particularly, this application relates to modifications of the plunger rod that may be used with standard or specialized pistons. This application also relates to modifications of a standard piston. Certain devices disclosed herein may be advantageously used for ocular injections or other injections in which surface sterilization of an internal cavity of a piston may be needed following filling or finishing of a syringe. Standard plunger rods may be limited in that surfaces within the piston cavity may not be subject to decontamination, or may not be conveniently decontaminated, when the standard plunger rod is attached to the piston. Document US 8007475 B2 describes a positive displacement flush syringe. Document US 2016/082194 A1 describes a syringe and prefilled syringe. SUMMARY OF THE DISCLOSURE Briefly stated, a plunger assembly for a fluid-dispensing syringe comprises a piston including an outer piston surface, an inner piston cavity having an inner piston surface and a female thread, a proximal piston end, and a distal piston end. A plunger rod includes a rod body having a proximal rod end and a distal rod end, with a threaded extension extending distally from the distal rod end. The threaded extension is advanced distally along a distal length and threadedly engages the female thread of the piston cavity along at least a portion of the distal length. The threaded extension has a ventilation feature configured with respect to the piston cavity to create a ventilation space between the threaded extension and the inner piston surface. The proximal piston end and the distal rod end are in spaced relation to form a primary fluid passageway portion from outside of the plunger assembly into the ventilation space within the piston cavity. In certain embodiments, the piston cavity has a proximal cavity end and a distal cavity end and includes a first longitudinal portion with at least one female thread. The first longitudinal portion is spaced apart from the distal cavity end. The threaded extension includes at least one male thread. The male thread has a proximal male thread end and a distal male thread end and is configured so that when the plunger rod is fully advanced distally, the distal rod end is in contact with the proximal piston end, and the proximal male thread end is located distally of the at least one female thread. The ventilation feature comprises a space between the threaded extension and the inner piston surface. In certain embodiments, the piston cavity has a proximal cavity end and a distal cavity end and includes a first longitudinal portion with at least one female thread. The first longitudinal portion is spaced apart from the distal cavity end. The threaded extension includes at least one male thread extending from a thread shank and having a proximal male thread end and a distal male thread end. The thread shank has a proximal thread shank end and a distal thread shank end, and the proximal male thread end is spaced apart from the proximal thread shank end. The ventilation feature comprises a space between the threaded extension and the inner piston surface. In certain embodiments, the rod body has an outer surface comprising an outer distal end surface and an outer side surface, and the rod body has an auxiliary passage extending from the outer surface and fluidly connecting to the ventilation feature. In certain embodiments, the piston cavity has a proximal cavity end and a distal cavity end and includes a first longitudinal portion with a plurality of female threads having a female-thread major diameter and a female-thread minor diameter. The threaded extension includes a plurality of male threads extending from a male thread shank and having a constant male thread major diameter. The male thread shank has a proximal male thread shank end, a distal male thread shank end, and a non-constant male thread shank diameter. The ventilation feature comprises a space between the male thread shank and the female-thread minor diameter. In certain embodiments, the ventilation feature comprises a plurality of spaces between the male thread shank and the female-thread minor diameter. In certain embodiments, the rod body has an outer surface comprising an outer distal end surface and an outer side surface, and the rod body has an auxiliary passage extending from the outer surface and fluidly connecting to the ventilation feature. In certain embodiments, the piston cavity has a proximal cavity end and a distal cavity end and includes a first longitudinal portion with a plurality of female threads having a female-thread major diameter and a female-thread minor diameter. The threaded extension includes a plurality of male threads extending from a male thread shank having a male thread shank axis. The male thr