The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1999
Filed:
Nov. 21, 1997
Gustav Levander, Bromma, SE;
Pharmacia & Upjohn Aktiebolag, Stockholm, SE;
Abstract
A piston rod for use in an injection device for an injection cartridge is provided with a single or multiple thread along a predetermined portion of its length, after which the thread changes into a longitudinal groove for each thread, such that a turning movement of the piston rod will turn into an axial movement after the predetermined length. The thread is shaped as one or more helicoidal grooves in the surface of the piston rod, the grooves turning into the longitudinal grooves after the predetermined length. A nut element cooperates with the thread and includes at least one radial inwardly directed projection for each thread, the projection or projections guiding the piston rod by the groove or grooves forming the thread.