US 12,246,168 B2
Needleless injectors and related methods
Masayoshi Fukushima, Orange, CA (US); and Daisuke Futakawa, Takaoka (JP)
Assigned to AIJEX PHARMA INTERNATIONAL INC., Toyama (JP)
Filed by AIJEX PHARMA INTERNATIONAL INC., Toyama (JP)
Filed on Jun. 29, 2021, as Appl. No. 17/362,665.
Prior Publication US 2022/0409816 A1, Dec. 29, 2022
Int. Cl. A61M 5/30 (2006.01); A61M 5/24 (2006.01); A61M 5/28 (2006.01); A61M 5/31 (2006.01); A61M 5/315 (2006.01)
CPC A61M 5/30 (2013.01) [A61M 5/24 (2013.01); A61M 5/281 (2013.01); A61M 5/3129 (2013.01); A61M 5/315 (2013.01); A61M 2005/2488 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A needleless injector comprising:
a force generator comprising a housing with a body having a distal end with an opening, a proximal end enclosed by an end wall having a passage, a side opening, and an interior;
a drive spring compressed between the end wall and a piston head having a bore, said piston head being held by a latch piece having a length and a width and pivotably mounted to the housing and holding the piston head against a bias of the drive spring in a ready to use position;
a piston rod located in the bore of the piston head, said piston rod having a shaft and a head section, wherein the shaft extends out the passage of the end wall and the head section having a push surface;
a coupling sleeve having a bore and having the shaft of the piston rod located in the bore;
wherein the shaft that extends out the passage is rotatable to move the piston rod relative to the piston head and move the push surface away from the piston head in the ready to use position; and
wherein the coupling sleeve has exterior threads threadedly engaged with threads in the bore of the piston head.