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:
Feb. 20, 2001
Filed:
Jul. 15, 1998
Russell H. Barton, New Westminster, CA;
Joel A. Ronne, Vancouver, CA;
Henry H. Voss, West Vancouver, CA;
Ballard Power Systems Inc., Burnaby, CA;
Abstract
An electrochemical fuel cell stack with an improved compression assembly comprises a tension member which is electrically non-conductive and preferably non-metallic. The tension member can be made from a composite material which has similar expansion and contraction properties as the stack materials, thereby reducing undesirable fluctuations in the compressive force applied to the stack. An improved apparatus for securing the improved tension member to the rest of the compression assembly is also provided. Preferred embodiments of an improved compression assembly employ a collet and wedges to grip the tension member and compress a resilient member which imparts a tensile force to the tension member and a compressive force to the fuel cell assemblies. In other embodiments, an improved compression assembly employs a unitary resilient member and fastener in combination with a tension member. The improved apparatus is easier to assemble in high speed manufacturing processes because the compression assembly can be assembled or installed using the same machinery which is used to compress the stack in one fixturing because the compression assembly is assembled by being stacked in essentially the same direction as the other fuel cell components. An improved method of assembling a compression assembly for an electrochemical fuel cell stack is also provided.