Abstract: Fluid delivery devices using a pair of meshed external gears, in spite of no reciprocating component for fluid delivery enabling low rotational vibration, the high noise due to the trapping phenomenon, and the teeth bouncing contact due to undesired large backlash heretofore afforded in the gear manufacturing process, restrict the employments in the industrial field requiring quiet environment such as electric motor vehicles or room services.

Abstract: Fluid delivery devices using a pair of meshed external gears, in spite of no reciprocating component for fluid delivery enabling low rotational vibration, the high noise due to the trapping phenomenon, and the teeth bouncing contact due to undesired large backlash heretofore afforded in the gear manufacturing process, restrict the employments in the industrial field requiring quiet environment such as electric motor vehicles or room services.

Abstract: The present invention relates to a wheelchair with forced driven front caterpillar wheels with a cable-hauling ratchet lever by which a user, by himself/herself, can pass over a road-block or drains on roads, lifts up the caterpillars from the ground for easy steering on caster wheel, engages/disengages the drive wheel having ratchet clutch in the detachable wheel hub to idle the drive wheel/caterpillars for converting from/to manual drive to/from drive by auxiliary power source, and prevents the drive wheel from rolling backward during climbing inclines and controls speed continuously on a slope by a band brake means. So the disabled persons on their legs can travel to outdoors by himself/herself without a care of neighbors.

Abstract: The present invention relates to a wheelchair with forced driven front caterpillar wheels with a cable-hauling ratchet lever by which a user, by himself/herself, can pass over a road-block or drains on roads, lifts up the caterpillars from the ground for easy steering on caster wheel, engages/disengages the drive wheel having ratchet clutch in the detachable wheel hub to idle the drive wheel/caterpillars for converting from/to manual drive to/from drive by auxiliary power source, and prevents the drive wheel from rolling backward during climbing inclines and controls speed continuously on a slope by a band brake means. So the disabled persons on their legs can travel to outdoors by himself/herself without a care of neighbors.