US 11,951,289 B2
Pharmaceutical syringe piston
Jeffrey M. Laubach, Emmaus, PA (US); Jurgen Brinkhues, Aachen (DE); Heike Gruen, Aachen (DE); Joel Worman, Palm Harbor, FL (US); Xia Zhao, Malvern, PA (US); and Jason Mattia, Downingtown, PA (US)
Assigned to West Pharmaceutical Services, Inc., Exton, PA (US)
Filed by West Pharmaceutical Services, Inc., Exton, PA (US)
Filed on May 31, 2022, as Appl. No. 17/828,046.
Application 17/828,046 is a division of application No. 16/354,675, filed on Mar. 15, 2019, granted, now 11,369,742.
Application 16/354,675 is a continuation of application No. 14/758,042, granted, now 10,258,744, issued on Apr. 16, 2019, previously published as PCT/US2013/035381, filed on Apr. 5, 2013.
Prior Publication US 2022/0288320 A1, Sep. 15, 2022
Int. Cl. A61M 5/315 (2006.01)
CPC A61M 5/31513 (2013.01) [A61M 2205/0222 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A piston manufactured by a method comprising:
placing a first rubber sheet and an inert film between die plates of a first forming tool;
vulcanizing the first rubber sheet and the inert film between the die plates of the first forming tool to form a first piston body, the first piston body comprising a central face portion at a distal axial end of the first piston body and an annular curved portion, the central face portion and at least a part of the annular curved portion being enclosed by the inert film;
blanking out the first piston body from the first rubber sheet and the inert film;
placing the first piston body into a second forming tool;
placing a second rubber sheet into the second forming tool;
vulcanizing the second rubber sheet and the first piston body together to form a second piston body, the second piston body comprising a proximal axial end that circumscribes the second piston body and a rib;
joining the second piston body to the first piston body to form the piston; and
blanking out the piston from the second rubber sheet at a trim edge, wherein:
the trim edge is spaced apart from the inert film between the inert film and the proximal axial end, and
an outer diameter of the trim edge is less than a maximum outer diameter of the rib.