Method and apparatus for simultaneously injecting a liquid and a transponder into an animal

An ejector for placement over a distal, open end of a syringe for administering liquid medication and adapted to simultaneously place an electronic transponder into living tissue, the ejector comprising a tubular hub having a first end for connection to the open syringe end;

• a hollow needle projecting from a second end of the hub and having a sharp end for entering the tissue, the hub defining a chamber which is concentric with the needle and has a diameter larger than an inside diameter of the needle;
• an elongated rod reciprocably disposed in the needle and having a length so that it extends from proximate the sharpened end of the needle into an interior of the syringe when the hub is secured to the syringe;
• a sleeve disposed in the chamber and movably engaging the rod for limiting longitudinal movements of the plunger relative to the needle so that the rod is prevented from moving under the influence of gravity out of the needle in either direction when the hub is secured to the syringe;
• and means limiting the extent to which the sleeve can move along the rod.

Apparatus for simultaneously injecting a liquid and placing an electronic transponder into living tissue, the apparatus comprising:

• a syringe having a hollow housing for holding the liquid, a liquid discharge end, and a plunger reciprocably disposed in the housing;
• a tubular hub secured to the discharge end of the housing and defining a relatively large cross-section chamber extending from the discharge end of the housing towards a distal end of the hub;
• a hollow needle projecting from the distal end of the hub and having a sharp, free end for insertion into the animal tissue;
• an elongated rod disposed inside the needle having a distal end proximate the sharp needle end, extending through the chamber, and having a proximal end disposed inside the housing so that the proximal end can be engaged by the plunger when it is moved relative to the housing towards the discharge end thereof and so that, during such movement, the plunger forcibly moves the rod towards the sharp end of the needle;
• and
• stop means operatively coupled with the rod for preventing movement of the rod under the influence of gravity out of the needle, the stop means including a sleeve disposed inside the chamber, in frictional engagement with the plunger and movable along a portion of the rod;
• whereby the transponder can be placed inside the needle proximate the sharp end thereof and movement of the plunger relative to the housing towards the discharge end simultaneously ejects liquid and the transponder from the sharp needle end into the animal tissue.

An ejector for use with and adapted to be attached to a discharge end of a syringe for injecting a liquid into animal tissue and simultaneously placing an object into the tissue, the ejector comprising a tubular hub adapted to be attached to a liquid discharge end of the syringe having proximal and distal ends;

• an elongated, hollow needle secured to the hub, projecting from the distal end and having a sharp end adapted to make an incision in the tissue, the needle terminating short of the proximal end of the hub, the hub defining a chamber between the proximal end of the needle and the proximal end of the hub which has a larger cross-section than the needle;
• an elongated rod reciprocably disposed in the needle, having a diameter less than the inside diameter of the needle and a sufficient length so that it extends into the syringe when the hub is attached to the syringe;
• retaining means disposed in the chamber including a sleeve movable along the rod for preventing the rod from axially moving under the influence of gravity out of either end of the needle;
• and stop means for limiting the extent to which the sleeve is movable along the rod and comprising first and second, longitudinally spaced-apart, radially oriented projections on the rod defined by upwelled material of the rod which engage and thereby limit the movement of the sleeve along the rod;
• whereby the object can be placed into the needle so that the object is forced by the rod through the incision into the tissue when a plunger of the syringe is moved towards the hub for injecting the liquid an thereby engages and moves the plunger relative to the needle towards the sharp end thereof.