Abstract: A retractable syringe includes a barrel [212], one end of which comprises a mounting collar[214]. A needle carrier [216] is releasably mounted within the collar [214], and releasably supports a needle cartridge [218]. A hypodermic needle [20] is mounted within the cartridge [218]. The collar [214] has inclined threads [650] in its bore wall for engaging lugs [248] on the carrier [216]. A cap [910] is provided with a flange [960] having a lower surface [962] wider than the proximal end of barrel [212] and dogs [952]. The dogs [952] are sized to insert into threads [650], whereby dogs [952] ride threads [650] to seal surface [962] against the proximal end of barrel [212].

Abstract: A retractable syringe includes a barrel [212], one end of which comprises a mounting collar [214]. A needle carrier [216] is releasably mounted within the collar [214], and releasably supports a needle cartridge [218]. A hypodermic needle [20] is mounted within the cartridge [218]. The collar [214] has inclined threads [650] in its bore wall for engaging lugs [248] on the carrier [216]. A cap [910] is provided with a flange [960] having a lower surface [962] wider than the proximal end of barrel [212] and dogs [952]. The dogs [952] are sized to insert into threads [650], whereby dogs [952] ride threads [650] to seal surface [962] against the proximal end of barrel [ 212].

Abstract: A retractable syringe includes a barrel, one end of which comprises a mounting collar. A needle carrier is releasably mounted within the collar, and releasably supports a needle cartridge. A hypodermic needle is mounted within the cartridge. A sheath attaches at one end to the cartridge, and at the other end to the collar. A plunger is telescoped into the barrel, and includes a relatively hard piston sealingly engaging the barrel. The piston includes a latch for engaging the carrier and releasing it from the collar. A pocket in the carrier has a support member in its center, and a pair of helical ribs for threadingly engaging a pair of tabs on the cartridge. The cartridge sealingly receives the support member. The collar has slots and inclined threads in its bore wall for engaging lugs on the carrier. The inclined threads have a friction bump near their blind ends. A retaining pin prevents relative rotation between the carrier and collar prior to desired retraction of the needle into the barrel.

Abstract: A retractable syringe includes a barrel [12, 212], one end of which comprises a mounting collar [14, 214]. A needle carrier [16, 216] is releasably mounted within the collar [14, 214], and releasably supports a needle cartridge [18, 218]. A hypodermic needle [20] is mounted within the cartridge [18, 218]. A sheath [22, 222, 418, 420, 422] attaches at one end to the cartridge, and at the other end to the collar. A plunger [36, 236] is telescoped into the barrel [12, 218], and includes a relatively hard piston sealingly engaging the barrel [12, 218]. The piston includes a latch [38, 238] for engaging the carrier [16, 216] and releasing it from the collar [14, 214]. A pocket [76, 476] in the carrier has a support member [54] in its center, and a pair of helical ribs [64] for threadingly engaging a pair of tabs on the cartridge [18, 218]. The cartridge [18, 218] sealingly receives the support member [54].

Abstract: A retractable syringe includes a resilient barrel, one end of which comprises a mounting collar. A needle carrier is releasably mounted within the collar, and releasably supports a needle cartridge. A hypodermic needle is mounted within the cartridge. A sheath attaches at one end to the cartridge, and at the other end to the collar. A plunger is telescoped into the barrel, and includes a relatively hard piston sealingly engaging the barrel. The piston includes a latch for engaging the carrier and releasing it from the collar. A pocket in the carrier has a support member in its center, and a pair of helical ribs for threadingly engaging a pair of tabs on the cartridge. The cartridge sealingly receives the support member. The collar has slots and inclined threads in its bore wall for engaging lugs on the carrier. The inclined threads have a friction bump near their blind ends. A retaining pin prevents relative rotation between the carrier and collar prior to desired retraction of the needle into the barrel.