Abstract: Seal means for sealing a bipolar plate to a membrane in a PEM fuel cell stack. The seal includes a thin layer of a cross-linkable silicone composition disposed between the bipolar plate and the membrane. The layer is applied as a liquid to either the plate or the membrane and preferably is polymerized prior to assembly of the stack. A preferred means for applying the composition to the bipolar plate is screen printing. Preferably, the layer has a thickness between 0.001 and 0.005 inch. The resulting fuel cell stack exhibits superior leak resistance. In a currently preferred embodiment, a layer of the silicone composition is provided at interfaces between a membrane and both an anode side and a cathode side of a bipolar plate.

Abstract: A solenoid coil/connector assembly includes a coil assembly having coil wires wound around a bobbin, an overmold encapsulating the coil assembly, and a plurality of seals formed between the bobbin and the overmold using laser light, the seals hermetically sealing the coil wires. By using a laser welding process for plastic materials directed at an internal interface between the bobbin and overmold the coil wires become hermetically sealed and moisture is thus prevented from gaining access to coil wires during use of the solenoid coil/connector assembly.

Abstract: A method and apparatus for overmolding a plastic shroud onto a bobbin including the step of providing a protrusion ring on the surface of the bobbin surrounding each standoff between the bobbin and a mold wall and extending outwards from the surface of the bobbin. A plurality of standoffs and protrusion rings is presently preferred. The protrusion rings are small relative to the standoffs, have low thermal mass, and thus are readily melted by the injected molten plastic, causing interstitching between the bobbin material and the overmolding material. The interstitching creates a highly effective hermetic seal against moisture leakage along the surface of the bobbin away from the standoff site. Perfect melting of the standoffs is no longer required, and standoffs can be designed to assure proper positioning of the bobbin during the complete overmolding process.

Abstract: A wiper seal subassembly for disposal in rotor vanes or stator lobes of a vane-type camshaft phaser comprises a backing spring and a sealing element. The sealing element includes spring retention features that loosely retain the backing spring and that are integrally molded into the sealing element. The spring retention features include undercut retention features, such as an overhanging edge, that prevent the backing spring from vertically detaching from the sealing element. The spring retention features further include sidewall tabs that prevent the backing spring from horizontally detaching from the sealing element. The sealing element is formed from a plastic composite material during an injection molding process using a simple injection mold tooling design. The single-piece wiper seal subassembly is provided at the tip of each rotor vane and/or stator lobe of a vane-type camshaft phaser for varying the timing of combustion valves in an internal combustion engine.

Abstract: A method and apparatus for overmolding a plastic shroud onto a bobbin including the step of providing a protrusion ring on the surface of the bobbin surrounding each standoff between the bobbin and a mold wall and extending outwards from the surface of the bobbin. A plurality of standoffs and protrusion rings is presently preferred. The protrusion rings are small relative to the standoffs, have low thermal mass, and thus are readily melted by the injected molten plastic, causing interstitching between the bobbin material and the overmolding material. The interstitching creates a highly effective hermetic seal against moisture leakage along the surface of the bobbin away from the standoff site. Perfect melting of the standoffs is no longer required, and standoffs can be designed to assure proper positioning of the bobbin during the complete overmolding process.

Abstract: A thermoplastic carrier sheet is die-cut to have a size and shape matching that of a PEM bipolar plate. A plurality of holes are punched in the carrier sheet in the pattern of gasket beading to be formed subsequently. In a mold, liquid gasket resin fills the mold on both sides of the carrier sheet to form the gasket, flowing through the holes in the sheet and thereby causing the gasket to become mechanically attached to the sheet. A carrier element having a flange portion substantially identical with the outer profile of the bipolar plates is laminated to the sheet edge. During assembly of a fuel cell, the carrier element automatically positions the gasket correctly on the plate and prevents the gasket from twisting or shifting. In a currently preferred embodiment, a membrane electrode assembly is attached within an appropriate opening in the carrier sheet.

Abstract: A method for attaching a gasket to a non-gasketed bipolar plate for a PEM fuel cell, including the steps of making a pattern of the gasket; preparing the bipolar plate surface; priming the bipolar plate surface for adhesive according to the gasket pattern; aging the primer coat; screen-printing an adhesive coat onto the primer according to the gasket pattern; positioning the gasket face-down in a mirror-image fixture having channels in the form of the gasket; positioning the bipolar plate face down onto the fixture and gasket; applying pressure to the plate to adhere the gasket thereto in the adhesive-coated areas; removing the plate and gasket subassembly from the fixture; and curing the adhesive to provide a gasketed bipolar plate.

Abstract: A fluid pulse damper having increased dynamic range and sensitivity, being especially useful in suppressing pulsations in the fuel supply rail of an internal combustion engine. The damper is a longitudinal gas-filled plastic pillow having walls formed by opposed flexible short sides and opposed flexible long sides, and includes at least one internal self-contact element, and preferably a plurality of such elements. As the short sides flex, the elements make contact internally, shifting the damper into a different compression regime and extending the pressure/response over an increased range of pressures. A feature of some embodiments is that the inner surface within the contact elements is shifted into tension after the elements make contact, thereby stiffening the damper and increasing the damper's resistance to further deformation. The damper is formed of a plastic such as ultra-high molecular weight polyethylenes, high flow polyetherimides, or tubing grade polyphthalamides.

Abstract: In a proton exchange membrane fuel cell assembly, a plurality of bores is provided in each anode plate and each cathode plate at a standard distance from the active area of each plate. The bores in the anode plate are stepped. Non-conductive stepped pins, each having a well in a large-diameter portion thereof, are inserted concentrically into the bores of adjacent anode and cathode plates to form a bipolar plate subassembly. The pins extend through the bipolar plate subassembly and have a reduced-diameter portion for engaging the wells of adjacent pins in an adjacent bipolar plate subassembly. Preferably, bores and pins are provided in rotational symmetry near opposite edges of each plate. The pins thus both align an anode and cathode to form a bipolar plate subassembly and also align a plurality of bipolar plate subassemblies, in combination with a plurality of proton exchange membranes therebetween, to form a fuel cell stack having all anode plates accurately aligned with all cathode plates.

Abstract: Seal means for sealing a bipolar plate to a membrane in a PEM fuel cell stack. The seal includes a thin layer of a cross-linkable silicone composition disposed between the bipolar plate and the membrane. The layer is applied as a liquid to either the plate or the membrane and preferably is polymerized prior to assembly of the stack. A preferred means for applying the composition to the bipolar plate is screen printing. Preferably, the layer has a thickness between 0.001 and 0.005 inch. The resulting fuel cell stack exhibits superior leak resistance. In a currently preferred embodiment, a layer of the silicone composition is provided at interfaces between a membrane and both an anode side and a cathode side of a bipolar plate.

Abstract: A thermoplastic carrier sheet is die-cut to have a size and shape matching that of a PEM bipolar plate. A plurality of holes are punched in the carrier sheet in the pattern of gasket beading to be formed subsequently. In a mold, liquid gasket resin fills the mold on both sides of the carrier sheet to form the gasket, flowing through the holes in the sheet and thereby causing the gasket to become mechanically attached to the sheet. A carrier element having a flange portion substantially identical with the outer profile of the bipolar plates is laminated to the sheet edge. During assembly of a fuel cell, the carrier element automatically positions the gasket correctly on the plate and prevents the gasket from twisting or shifting. In a currently preferred embodiment, a membrane electrode assembly is attached within an appropriate opening in the carrier sheet.

Abstract: Seal means for sealing a bipolar plate to a membrane in a PEM fuel cell stack. The seal includes a thin layer of a cross-linkable silicone composition disposed between the bipolar plate and the membrane. The layer is applied as a liquid to either the plate or the membrane and preferably is polymerized prior to assembly of the stack. A preferred means for applying the composition to the bipolar plate is screen printing. Preferably, the layer has a thickness between 0.001 and 0.005 inch. The resulting fuel cell stack exhibits superior leak resistance. In a currently preferred embodiment, a layer of the silicone composition is provided at interfaces between a membrane and both an anode side and a cathode side of a bipolar plate.

Abstract: A method for attaching a gasket to a non-gasketed bipolar plate for a PEM fuel cell, including the steps of making a pattern of the gasket; preparing the bipolar plate surface; priming the bipolar plate surface for adhesive according to the gasket pattern; aging the primer coat; screen-printing an adhesive coat onto the primer according to the gasket pattern; positioning the gasket face-down in a mirror-image fixture having channels in the form of the gasket; positioning the bipolar plate face down onto the fixture and gasket; applying pressure to the plate to adhere the gasket thereto in the adhesive-coated areas; removing the plate and gasket subassembly from the fixture; and curing the adhesive to provide a gasketed bipolar plate.

Abstract: The present invention generally includes a composite fuel rail with integral damping provided by flat sections, molded into the rail conduit, that flex in response to a pressure pulsation and a co-injected composite laminate structure wherein the compounds of the laminates can be selectively varied to provide impact resistance, chemical resistance and a vapor permeation barrier, as needed.

Abstract: In a proton exchange membrane fuel cell assembly, a plurality of bores is provided in each anode plate and each cathode plate at a standard distance from the active area of each plate. The bores in the anode plate are stepped. Non-conductive stepped pins, each having a well in a large-diameter portion thereof, are inserted concentrically into the bores of adjacent anode and cathode plates to form a bipolar plate subassembly. The pins extend through the bipolar plate subassembly and have a reduced-diameter portion for engaging the wells of adjacent pins in an adjacent bipolar plate subassembly. Preferably, bores and pins are provided in rotational symmetry near opposite edges of each plate. The pins thus both align an anode and cathode to form a bipolar plate subassembly and also align a plurality of bipolar plate subassemblies, in combination with a plurality of proton exchange membranes therebetween, to form a fuel cell stack having all anode plates accurately aligned with all cathode plates.

Abstract: The present invention generally includes a composite fuel rail with integral damping provided by flat sections, molded into the rail conduit, that flex in response to a pressure pulsation and a co-injected composite laminate structure wherein the compounds of the laminates can be selectively varied to provide impact resistance, chemical resistance and a vapor permeation barrier, as needed.

Abstract: A fuel injection nozzle has a tubular body adapted to receive fuel, a tubular seat member mounted to the body, the seat member having an opening for discharging fuel and a valve seat surrounding the opening, a poppet valve member engageable with the valve seat to interrupt fuel flow through the opening, and an extension spring anchored to the body and to the valve member and biasing the valve member to engage the valve seat. The extension spring is a helically coiled spring with each coil lying close to the adjacent coils and with the coils at one end overlying an end of the body to anchor the spring to the body and to cause fuel flowing through the nozzle to pass between the coils of the spring; the spring thereby acts as a filter for fuel to be discharged by the nozzle. The seat member is axially movable relative to the body to adjust the length of the spring and thus the bias on the valve member whereby the desired valve-opening pressure differential may be established.