Abstract: A gear drive system is provided having a first gear and a second gear. The second gear has a first peripheral portion and a second peripheral portion. A first set of gear teeth can be defined peripherally over the first peripheral portion and/or the second peripheral portion. The first peripheral portion and/or the second peripheral portion can be more resilient, resulting in a first backlash between the first set of gear teeth and the teeth of the first gear, less than a second backlash between the second set of gear teeth and the teeth of the first gear. Each gear tooth of the second gear can have a gear tooth spacing between adjacent gear teeth. The gear tooth spacing over the first peripheral portion and/or the second peripheral portion can be less than the gear tooth spacing at portions other than the first peripheral portion and/or the second peripheral portion.

Abstract: A gear drive system is provided having a first gear and a second gear. The second gear has a first peripheral portion and a second peripheral portion. A first set of gear teeth can be defined peripherally over the first peripheral portion and/or the second peripheral portion. The first peripheral portion and/or the second peripheral portion can be more resilient, resulting in a first backlash between the first set of gear teeth and the teeth of the first gear, less than a second backlash between the second set of gear teeth and the teeth of the first gear. Each gear tooth of the second gear can have a gear tooth spacing between adjacent gear teeth. The gear tooth spacing over the first peripheral portion and/or the second peripheral portion can be less than the gear tooth spacing at portions other than the first peripheral portion and/or the second peripheral portion.

Abstract: The invention relates to a method for operating a dosing pump, the pump being driven by an asynchronous motor, comprising a drive which converts the motor revolutions into pump strokes of a defined stroke frequency. The pump strokes are comprised of a pump suction stroke and of a pump delivery stroke. Pump strokes are continuously carried out during a dosing phase. The aim of the invention is to provide a solution concerning a dosing pump having an asynchronous motor drive, a frequency converter thereto, and a control unit which interacts therewith in which the dosing behavior is improved during the operation of dosing pumps having an asynchronous motor drive.

Abstract: This invention provides a sealing mechanism for sealing the piston-cylinder unit of a reciprocating diaphragm pump to ensure that the piston-cylinder unit is permanently and reliably sealed while being simple to assemble. The invention further provides a piston-cylinder unit which has almost no play in the micrometer (&mgr;m) range, and which is sealed by hydrodynamically sealing a slot thereof.

Abstract: A dosing pump for dosed liquid conveyance that includes a suction valve built into a suction tube coming out of a suction container, a pump chamber having a displacement volume that can be modified by means of a pumping member, a pressure valve leading to a dosing tube, a deaeration device arranged on the top end of the tube and comprising a return valve and a flow-actuated deaeration and bypass valve built into a deaeration valve having response characteristics dependent upon the state of aggregation of the liquid contained therein. The flow-activated deaeration and bypass valve is open when idle, only closing when pressure is raised in the presence of liquid in the valve, and is provided with a membrane. Faulty pump operation is substantially reduced when the membrane is connected to a remote closing member which closes the deaeration tube when the membrane is moved. A return valve is arranged between the membrane and the closing member.

Abstract: Metering pumps for the metered feed of liquids are fitted with an intake valve built into an intake line from an intake container, a pump chamber downstream of it with a pumping component altering its displacement volume, a pressure valve leading to the metering connector and a vent and by-pass valve built into a return line leading to the intake container. In order to keep the quality of by-passed metering liquid as small as possible while maintaining adequate venting, there is valve chamber between the pressure valve and the pump chamber and separated from the latter by a return valve and a movable control wall, in which is incorporated the vent controlled by the control wall, opening on the suction stroke of the pumping component and closing on its delivery stroke. .There is also preferably in the valve chamber a prestressed displacement wall altering the volume of the valve chamber in the opposite direction to that of the control wall.

Abstract: A piston diaphragm pump operable for delivering doses of liquids such as surfactants, or wetting agents, for example, includes a pump piston that is reciprocally moveable within a pump tube that encloses a pump pressure chamber. The pump piston is electromagnetically driven against the force of a return spring by a magnetic coil that surrounds the pump tube. In addition, a pump diaphragm is rigidly clamped about an inner circumference to a portion of an upper end of the pump piston. The outer circumference of the pump diaphragm is rigidly clamped about its periphery between upper and middle housing sections. One side of the diaphragm faces a suction chamber, and the other side faces a pressure chamber. A longitudinal bore, that encloses a pump piston provided with a piston valve, extends centrally through the pump diaphragm and links the pressure chamber to the suction chamber.