Syringe holder/driver and syringe arrangement and syringe/holder driver therefor

Claim 1

A force-applying holder/driver unit for a syringe to effect relative fluid discharge motion between a syringe body and a syringe plunger, comprising: a housing for holding a syringe body, said housing having a syringe-securing section at one end, said syringe-securing section having a mouth formed therein for receipt of a syringe having a body with a fluid holding chamber therein and a longitudinally slidable plunger for discharge of fluid therefrom, retention means on said syringe-securing section for releasable retention of a said syringe body within said mouth, a plunger pusher longitudinally movably disposed within said housing and being adapted to engage the slidable plunger of a said syringe in pushing relation, said plunger pusher having a pair of drums freely rotatably mounted on said plunger pusher in spaced parallel relationship, a pair of constant force normally coiled web springs each of which is secured at one end thereof onto a respective one of said drums, the opposite ends of each of said constant force normally coiled web springs being secured in anchored relation to said housing adjacent the end of said housing having said syringe-securing section, said constant force coiled web springs being mounted with their respective coils extending in opposite lateral directions away from one another such that the web strip portions thereof extending between their opposite secured ends tend to bow outwardly convexly laterally away from one another. said housing having spaced longitudinally extending fixed lateral spring-retainer elements laterally engaging and retaining the respective intermediate web strip portions of said springs during uncoiling and coiling of said springs and in the extended and wound positions of said springs, said springs being spaced from a syringe when a said syringe is secured in retained position within said housing and being free of sliding contact with said fixed lateral spring-retainer elements and other portions of said housing during coiling of said spring to effect fluid discharge relative motion between a syringe plunger and syringe body which may be secured within said housing by said syringe-securing section, said plunger pusher being freely carried solely by said constant force coiled web springs and being free of any sliding engagement with or sliding side support by said housing or any longitudinal guides, said plunger pusher being held in a centered position spaced from said housing during plunger-movement-effecting retention solely by said springs which engage said side spring-retainer elements in a non-sliding strip-laying/removal engagement during longitudinal movement of said plunger pusher, and by contact with a syringe plunger when a syringe is secured within said mouth of said syringe-securing section.