Injection needle guide

Claim 1

A HYPODERMIC SYRINGE COMPRISING A HOLLOW LIGHTTRANSMITTING SMOOTH BORE OUTER BARREL OPEN AT ONE END, A CYLINDER ADAPTED TO RECEIVE A PLUNGER AND HAVING A SMOOTH EXTERIOR SURFACE SLIDEABLY MOUNTED IN THE BARREL THROUGH AND EXTENDING BEYOND THE OPEN END OF THE BARREL AND VISIBLE THROUGH THE WALL OF THE BARREL, MEANS INTERPOSED BETWEEN THE BORE OF THE BARREL AND THE EXTERIOR SURFACE OF THE CYLINDER TO FRICTIONALLY RESTRAIN THE CYLINDER IN ANY SELECTED ONE OF A NUMBER OF INCREMENTALLY DISTINCT POSITIONS RELATIVE TO THE BARREL, A LONG HYPODERMIC NEEDLE SHEATH HAVING INSIDE AND OUTSIDE DIAMETERS EACH SEVERAL TIMES SMALLER THAN THE INSIDE AND OUTSIDE DIAMETERS OF THE BARREL, RESPECTIVELY, AND BEING MOUNTED AT ONE END THEREOF AN A SECOND GENERALLY CLOSED END OF THE BARREL, A LONG NEEDLE MOUNTED ON THE FORWARD END O F THE CYLINDER AND ALWAYS EXTENDING THROUGH AND WELL BEYOND THE SMALL OPENING AND LOOSELY EXTENDING THROUGH AT LEAST ALMOST THE ENTIRE LENGTH OF THE ENCLOSING NEEDLE SHEATH, SAID BARREL CARRYING GRADUATIONS SO THAT THE CYLINDER MAY BE SELECTIVE LY POSITIONED WITHIN THE BARREL RELATIVE TO THE BARREL TRADUATIONS (A) FOR LOCATING THE NEEDLE TIP SLIGHTLY WITHIN THE SHEATH AT THE LEADING END OF THE SHEATH TO ACCOMMODATE PRECISE LOCATION AND REMOVAL OF THE LEADING END OF THE SHEATH ADJACENT THE BODY OF A PATIENT PRIOR TO AND FOLLOWING PENETRATION, RESPECTIVELY, AND (B) FOR ADVANCING THE NEEDLE TIP FROM THE SELECTIVELY POSITIONED LEADING END OF THE SHEATH A DISTANCE CORRESPONDING TO THE BARREL GRADUATIONS CAUSED TO BE TRAVERSED BY THE CYLINDER TO INJECT ONLY THE NEEDLE TIP TO A DESIRED DEPTH INTO THE PATIENT AT SAID PRECISE LOCATION.