Abstract: The present invention relates to a pumping device for delivering and metering fluids, in particular medical fluids such as dialysis fluids, with a piston unit having a driving device and a piston and with a membrane unit which has a membrane and a first chamber bordered by the membrane. The pumping device also has a hydraulic unit which has a space to accommodate a hydraulic fluid which is connected to the piston of the piston unit and to the first chamber of the membrane unit. The reliability of metering by such a pumping device is increased by providing a control unit for guaranteeing a predefinable metering rate and/or quantity and also providing a measuring device by means of which the axial position of the piston unit can be determined directly and which can be connected to the control unit.
Type:
Grant
Filed:
November 18, 1999
Date of Patent:
January 6, 2004
Assignee:
Fresenius Medical Care Deutschland GmbH
Inventors:
Martin Herklotz, Hans-Peter Schneider, Jörg Bigalke, Rainer Dönig, Jürgen Häcker
Abstract: A rotary drive unit powers a double-acting cam and a Geneva drive. The cam actuates two double-acting pumps which supply pressurized hydraulic fluid to a double-acting motor. A punch is reciprocated by the motor to punch sectors from a sheet material. The Geneva drive rotates a carrier which is indexed to receive material punched from the sheet. The hydraulic fluid is maintained in the system by a pair of check valves which deliver fluid as required from a pressurized reservoir to the pumps during a low pressure portion of the pumping cycle. Also provided are bleed and fill valves and pressure relieve valves which further assist in filling the system and controlling the maximum system pressure.
Abstract: A liquid pressure control system for advancing logs (19) towards a rotary cutter wheel (10) in timed relationship to successive cuts by cutters on that wheel (10). A cam arrangement (52) on the cutter wheel (10) actuates jerk pumps (71 and 72) to dispense hydraulic fluid to hydraulic rams (33 and 34) in the timber feed mechanism (18).
Abstract: An apparatus providing for the generation, control and application of power to a cyclic functioning machine, using fluids under pressure to transmit and control energy by means of a rotary, segmented cam wheel. The cam wheel provides a plurality of interchangeable segments formed into a rim portion with axially spaced complementary counteracting cam faces formed about opposite rim ends. An individual cam follower, carried on a piston rod of a related hydraulic cylinder, coacts with each of the cam faces to accurately regulate the flow of hydraulic fluid to and from a working cylinder of a machine to provide timed and synchronized machine functions through the control movement of the working cylinder. The contoured configuration of the cam faces are arranged to provide for a desired acceleration and retardation of machine motions. Further, variable speed drive means, employed to drive the cam wheel, provides a timing adjustment between machine cycles.
Abstract: This hydraulic coupling and speed multiplying mechanism consists of an annular cylinder block having several rows of radial transmitting cylinders wherein are operatively disposed the corresponding radial pistons. The pistons in each circular row are uniformly spaced apart, while laterally adjacent pistons are angularly off-set relative to each other. Centrally disposed in said annular cylinder block is a cam assembly which actuates the pistons in one row simultaneously and the several rows sequentially. The transmitting cylinders in one row are interconnected and have a common pipeline. Two rows of transmitting cylinders are connected to a receiving cylinder a piston in which actuates a crankshaft to which may be connected any desired rotary device.
Abstract: A hydraulically actuated power cylinder reciprocates a driver to exert a compressive force to upset a rivet with the power cylinder's movement being made to correspond to the movement of a pump cylinder by a fluid connection therebetween. The pump cylinder's movements are mechanically actuated according to a programmed cam and actuation is made to occur only during the riveting cycle by a control circuit operating a clutch and brake with the circuit inhibiting operation upon the sensing of a malfunction.
Type:
Grant
Filed:
December 30, 1974
Date of Patent:
May 11, 1976
Assignee:
The Milford Rivet & Machine Company
Inventors:
Richard L. Markus, William P. Hidden, Daniel F. Hefler