Self-sheathing hypodermic syringe

A self-sheathing means syringe assembly comprising:

• tubular-shaped sheathing means having an open end and an aperture formed in an oppositely disposed end;
• a tubular-shaped outer tube member telescopically engaged with said sheathing means, said outer tube member having an open end and an oppositely disposed apertured end, said outer tube member having an abutment proximate said open end;
• means disposed at said apertured end of said outer tube member for receiving a needle;
• means associated with said outer tube member for angularly aligning said outer tube member with said sheathing means;
• means engaged with said outer tube member for preventing said outer tube member from being disengaged from said sheathing means;
• a camming member rotatably supported on said open end of said outer tube member adjacent said abutment, said camming member further disposed between said outer tube member and said sheathing means proximate said open end, said camming member further having a first portion defining a camming contour at one end and a second portion defining a means for releasing said outer tube member of said syringe for movement relative to said tubular-shaped sheathing means, said camming contour having a first detent and a second detent;
• means formed on said outer tube member for camming against said camming contour of said first portion of said camming member;
• first means for locking said outer tube member in a predetermined locked position, said first locking means being mounted to said tubular-shaped sheathing and being engagable with said outer tube member for maintaining said outer tube member in said predetermined locked position wherein said needle receiving means of said outer tube member is adjacent and extending in a direction protecting from said apertured end of said tubular-shaped sheathing means;
• means for biasing said outer tube member in a direction away from said apertured end of said tubular-shaped sheathing means, said biasing means being mounted contiguous said apertured end of said outer tube member and said apertured end of said tubular shaped sheathing means so as to bias said first locking means whereby as said releasing means of said camming member is moved in a first predetermined direction for dispensing the contents of said syringe, said releasing means communicates with said first locking means to disengage said outer tube member from said first locking means such that said outer tube member and associated needle under the influence of said biasing means shuttles said outer tube member from said predetermined locked position to a retracted position within said tubular-shaped sheathing means;
• and
• second locking means mounted to said tubular-shaped sheathing means for maintaining said outer tube member in said retracted position wherein said needle receiving means of said outer tube member is axially displaced from said apertured end of said tubular-shaped sheathing means, said second locking means further comprising means for puncturing said outer tube;
• such that rotation of said camming member relative to said outer tube member causes said camming means to disengage said first detent and engage said second detent for dispensing the contents of the syringe, whereafter said releasing means disengages said first means for locking from said outer tube member such that said outer tube member shuttles from said predetermined locked position to said retracted position and any further attempt to shuttle said outer tube member back to said predetermined locked position activates said puncturing means to puncture said outer tube member so as to prevent reuse of said syringe.