NEEDLE FREE INJECTOR IN THE FORM OF ROD Russian patent published in 2017 - IPC A61M5/30 

FIELD: medical equipment.

SUBSTANCE: invention relates to medical equipment, namely, to needle-free devices for injections in the form of rod. Device comprises the following components: cylinder case consisting of two parts in the form of tube including front and rear parts; the first chamber arranged at front outlet end of the above front part; one-way hydraulic control valve located in the front part and intended to receive input liquid from the input source of fluid and feeding said liquid into the first chamber; tip on the front end of the named cylindrical housing, intended for liquid discharge from the first chamber; plunger sliding in cylindrical housing and performing movement between the position of rear retraction, at which liquid is pulled into the first chamber, and sliding forward position at which liquid is discharged through the said tip. In this case the rear part of the cylindrical body comprises an elongated body of tubular shape and tubular plug coupling the elongated body of tubular shape in the rear part with rear end of the front part. Note here that tubular plug passes in the elongated body of tubular shape and comprises second chamber, arranged behind said first chamber and separated from it; a piston sliding in said second chamber and performing movement under the action of fluid medium between position of sliding forward, at which it moves the plunger in the position of sliding forward, and position of rear retraction at which it moves the plunger in rear position. Body of tubular shape and tubular plug form the third chamber located in the above cylindrical housing, surrounding the second chamber and adapted for alternate receiving pressurized gas from said second chamber during piston retraction from rear position to position of sliding forward and release of compressed gas into said second chamber during movement of the said piston from sliding forward in rear position. Hole in said body of tubular shape allows gas to pass between the second and third chambers. Plug with a hole closes body rear end of tubular shape in the cylindrical body and includes the first channel, intended to receive compressed gas from gas source and this gas transportation to the piston rear end to make piston move from retraction in sliding forward position, and the second channel is intended for transportation of compressed gas in the third chamber and from it in order to cause motion of the piston alternately from rear to position of sliding forward and from sliding forward in rear position. Magnetic device is located on the rear end of said piston and is intended to attract the piston to the plug with a hole so that the piston remains in rear position until the compressed gas is introduced into the second chamber behind the piston. Pair of pipes, connecting the rear end of said plug with a hole, are intended for transportation of compressed gas to the plug with a hole and from it.

EFFECT: injection of drug.

5 cl, 18 dwg