Multiple dosage inoculator

Claim 1

An inoculator for administering metered doses of injectable preparations to patients comprising: a source of supply for the injectable preparation to be administered; a metering chamber in communication with said source of supply; a hollow needle in communication with said metering chamber; a cylindrical muzzle spaced from and surrounding said needle, said cylindrical muzzle extending at least as far as the tip of said needle and having an essentially flat edge at the end thereof; a vacuum source connected to said muzzle in order to impale the skin of the patient being inoculated on said needle; a bellows; a piston mounted for reciprocal forward and rearward movement in said bellows, the rearward end of said piston being in communication with the rearward wall of said bellows, and the front end of said piston extending beyond the front edge of said bellows and being sliDingly engaged with the interior wall of the metering chamber; and a hollow tube one end of which is connected to the vacuum source, and the other end being connected to the interior of said bellows in order to cyclicly collapse and expand said bellows, thereby causing said piston to move forward and rearward in said metering chamber, whereby the piston only moves to inject the metered dose of injectable preparation when the muzzle is sealed against the skin of the patient.