Device for assembling a banded fuel cell stack
A device for assembling a banded fuel cell stack with at least one custom-fit band comprises a frame, a base to support the stack while assembling, a press plate that is movable toward and away from the base to compress the stack under a constant force, band folding means to fold the band around the compressed stack such that the ends of the band overlap and welding means for welding the overlapped ends of the band. A method for assembling the banded fuel cell stack with at least one custom-fit band is also described. The device can be used to fit a plurality of compression bands around the assembled stack.
1 . A device for assembling a banded fuel cell stack with a custom-fit welded band comprising:
a frame;
a base mounted on the frame for supporting the stack while assembling;
a press plate that is movable toward and away from the base to compress the stack under a constant force;
band folding means to fold the band ends around the compressed stack while being compressed such that the band ends overlap; and
welding means to weld the overlapped ends of the band.
2 . The device of claim 1 wherein the base further comprises:
a stack support plate;
at least one band guide to position at least one band on the base;
stack guides to guide the stack during installation on the device; and
lateral stack locating means for positioning and guiding the stack during operation.
3 . The device of claim 2 wherein the stack guides comprise runners of a greater height than the band guide for supporting the stack.
4 . The device of claim 1 wherein the band folding means comprises first folding means to fold the bands in a first direction around the stack.
5 . The device of claim 1 wherein the band folding means comprises second folding means to fold the bands in a second direction perpendicular to the first direction.
6 . The device of claim 1 wherein the welding means is a laser-welding device.
7 . The device of claim 1 whereby at least two stacks are assembled and the height of one stack is different than the height of the other stack.
8 . A method of assembling a banded fuel cell stack with a custom-fit welded band comprising the steps of:
providing the device of claim 1;
compressing the stack under a predetermined compression force by lowering the press;
positioning at least one band within the band guides on the base;
folding at least one band around the compressed stack; and
welding the overlapped ends of each band using the welding means of the device.
9 . The method of claim 1 further comprising the step of first sliding a pre-compressed stack on the stack guides to position it on the stack support plate of the device and locating the stack in the operating position.
10 . The method of claim 1 wherein folding the band around the compressed stack comprises lowering the stack support plate to give an initial fold to the band, activating the first folding tools to fold the band in a first direction around the stack and activating the second folding tools to fold both ends of the band in a second direction around the stack, perpendicular to the first direction, so that the ends of the band overlap.
11 . The method of claim 1 whereby at least two stacks are assembled and the height of one stack is different than the height of the other stack.