Patent ID: 6905478
Filing Date: 2005-06-14
Classification: A61M

Abstract:
1. A syringe including: an outer barrel having first and second ends, an inner barrel slidable longitudinally within said outer barrel and adapted to support a needle at one end thereof which needle projects through an aperture in said first end of said outer barrel, said needle being in fluid communication with a fluid retaining chamber of said inner barrel, and a plunger within said chamber and actuable to draw fluid into said chamber and expel fluid from said chamber via said needle, said plunger being connected to an actuating rod extending out from the other end of said inner barrel and the second end of said outer barrel, said outer barrel having retaining means on an inner wall surface thereof, and said inner barrel having latching means for engaging said retaining means and latching said inner barrel in either of two positions relative to said outer barrel, a first said position being one in which said needle projects from said outer barrel and is in a useable position, and a second said position being one in which said needle is fully retracted within said outer barrel, biasing means for biasing said inner barrel towards said second position and said plunger actuating rod having means for contacting said latching means when said plunger is fully depressed to disengage said latching means from said retaining means whereby said needle moves to said second position wherein said latching means engages said retaining means and is permanently retained, and wherein a limit catch is provided on said actuating rod, said limit catch preventing said plunger from being fully depressed and disengaging said latching means from said retaining means on an initial actuation of said plunger but allowing said plunger to be depressed sufficiently to disengage said latching means on the next plunger depression.