Abstract: A pump is formed by a housing (10) having an inlet (11) for connection to a source of fluid and an outlet (12) for pumped fluid. A rotor (15) is rotatable within the housing and the inlet (11) and the outlet (12) are spaced apart around the path of the rotor (15) in the housing. The rotor (15) has surfaces (16a, 16b, 16c, 16d) that form, with the housing (10), closed chambers (18a, 18b, 18c, 18d) which travel around the housing (10) to convey fluid from the inlet (11) to the outlet (12). The housing (10) carries a seal (14) that is located between the inlet (11) and the outlet (12) in the direction of travel of the rotor (15). The seal (14) co-operates with the rotor surfaces (16a, 16b, 16c, 16d) as the surfaces (16a, 16b, 16c, 16d) pass between the outlet (12) and the inlet (11) to prevent the formation of a chamber during said passage and so prevent fluid flow from the outlet (12) to the inlet (11). Such a pump is easily and cheaply produced and is particularly useful in medical applications.

Abstract: A fuel cell stack manifold system in which a flexible manifold body includes a pan having a central area, sidewall extending outward from the periphery of the central area, and at least one compound fold comprising a central area fold connecting adjacent portions of the central area and extending between opposite sides of the central area, and a sidewall fold connecting adjacent portions of the sidewall. The manifold system further includes a rail assembly for attachment to the manifold body and adapted to receive pins by which dielectric insulators are joined to the manifold assembly.

Abstract: A fuel cell stack manifold system in which a flexible manifold body includes a pan having a central area, sidewall extending outward from the periphery of the central area, and at least one compound fold comprising a central area fold connecting adjacent portions of the central area and extending between opposite sides of the central area, and a sidewall fold connecting adjacent portions of the sidewall. The manifold system further includes a rail assembly for attachment to the manifold body and adapted to receive pins by which dielectric insulators are joined to the manifold assembly.

Abstract: A manifold and manifold sealing assembly for use with a fuel cell stack having a plurality of faces in which the assembly includes a plurality of frame assemblies and a plurality of manifolds, and at least one frame assembly adjacent a given face of the fuel cell stack provides support for a part of the frame assembly abutting the face of the stack adjacent the one face. Additionally, the manifold abutting the one frame assembly and the manifold abutting the supported frame assembly are adapted to sealingly engage in the area of support.

Abstract: A manifold and manifold sealing assembly for use with a fuel cell stack having a plurality of faces in which the assembly includes a plurality of frame assemblies and a plurality of manifolds, and at least one frame assembly adjacent a given face of the fuel cell stack provides support for a part of the frame assembly abutting the face of the stack adjacent the one face. Additionally, the manifold abutting the one frame assembly and the manifold abutting the supported frame assembly are adapted to sealingly engage in the area of support.

Abstract: A fuel cell stack compression system in which a spring assembly and mechanical linkage assembly are used in conjunction with tie rods and tie bars to apply a compressive load to a fuel cell stack. The linkage assembly includes a lever and three pins to redirect the force or movement generated by the spring assembly into a movement or force for the tie rods. The tie rods, in turn, connect to the tie bars which span the top end plate of the fuel cell stack and transfer the load to the stack. The linkage also includes a slotted bearing which compensates for the circular arc formed by the lever and allows the spring assembly to be rigidly mounted under the bottom end plate. The spring assembly comprises multiple springs arranged in parallel and designed to provide a non-linearly decreasing load as the stack compresses due to cell consolidation. This load profile reduces overall stack shrinkage while providing high pressure at the beginning of life to insure proper cell-to-cell contact.

Abstract: A low profile switch or keypad has one or more touch buttons of circular or polygonal shape in plan formed integrally with and raised from a surrounding membrane of elastomeric material by a wall of resiliently deformable material of thickness and angle relative to the membrane so that the wall can flex under finger pressure on the or each button without deflecting the surrounding membrane. The membrane and at least the periphery of the button are relatively thick and the wall is relatively thin so that deformation during the keystroke is localized in the wall. The length of the wall is about equal to the keystroke and is relatively small compared to the width of the touch button. The junction between the wall and the membrane is located a distance greater than the keystroke above the lower surfaces of the membrane so that the wall passes overcenter during the keystroke resulting in a change in tactile sensation.

Abstract: A low profile switch or keypad has one or more touch pads (14) formed integrally with and raised from a surrounding membrane or key mat (15) of elastomeric material by a wall (30) of resiliently deformable material of thickness and angle relative to the mat (15) so that the wall (30) can flex under finger pressure on the or each pad (14) without deflecting the surrounding membrane. The underside of each pad (14) is formed with a convex contact pad (29) dimensioned in relation to the pad diameter and travel and the length of wall (30) so that the pad (29) makes surface to surface contact with conductors (12), (13) of an underlying circuit board (10). The mat (15) is held in tension to the board (10) fits. The keyboard uses only two interfitting parts and needs no bezel but provides a tactile response to key depression.

Abstract: A pump is formed by a housing (10) having an inlet (11) for connection to a source of fluid and an outlet (12) for pumped fluid. A rotor (15) is rotatable within the housing and the inlet (11) and the outlet (12) are spaced apart around the path of the rotor (15) in the housing. The rotor (15) has surfaces (16a, 16b, 16c, 16d) that form, with the housing (10), closed chambers (18a, 18b, 18c, 18d) which travel around the housing (10) to convey fluid from the inlet (11) to the outlet (12). The housing (10) carries a seal (14) that is located between the inlet (11) and the outlet (12) in the direction of travel of the rotor (15). The seal (14) co-operates with the rotor surfaces (16a, 16b, 16c, 16d) as the surfaces (16a, 16b, 16c, 16d) pass between the outlet (12) and the inlet (11) to prevent the formation of a chamber during said passage and so prevent fluid flow from the outlet (12) to the inlet (11). Such a pump is easily and cheaply produced and is particularly useful in medical applications.

Abstract: A pump is formed by a housing (10) having an inlet (11) for connection to a source of fluid and an outlet (12) for pumped fluid. A rotor (15) is rotatable within the housing and the inlet (11) and the outlet (12) are spaced apart around the path of the rotor (15) in the housing. The rotor (15) has surfaces (16a, 16b, 16c, 16d) that form, with the housing (10), closed chambers (18a, 18b, 18c, 18d) which travel around the housing (10) to convey fluid from the inlet (11) to the outlet (12). The housing (10) carries a seal (14) that is located between the inlet (11) and the outlet (12) in the direction of travel of the rotor (15). The seal (14) co-operates with the rotor surfaces (16a, 16b, 16c, 16d) as the surfaces (16a, 16b, 16c, 16d) pass between the outlet (12) and the inlet (11) to prevent the formation of a chamber during said passage and so prevent fluid flow from the outlet (12) to the inlet (11). Such a pump is easily and cheaply produced and is particularly useful in medical applications.