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:
Apr. 21, 1992
Filed:
May. 23, 1991
Ronald S Conero, San Diego, CA (US);
IVAC Corporation, San Diego, CA (US);
Abstract
Automatic engagement of a lead screw with a lead screw drive mechanism. A plunger driver used to move the plunger of a syringe is connected to the screw drive mechanism. A first detector provides a plunger signal indicating the presence of a syringe plunger in the plunger driver and a second detector provides a thread engagement signal indicating engagement or disengagement of the lead screw drive mechanism with the lead screw. The thread engagement detector monitors movement of a rigid linkage at the screw drive mechanism which has a nonlinear characteristic curve. In the case where the plunger signal indicates the presence of a plunger and the thread engagement signal indicates engagement of the drive mechanism with the lead screw, the lead screw is rotated in a forward direction to remove the thread clearance. In the case where the thread engagement signal indicates disengagement of the drive mechanism with the lead screw, the processor rotates the lead screw first in a reverse direction and then in a forward direction to cause engagement of the threads.