Patents by Inventor Ludwig K. Holtermann

Ludwig K. Holtermann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5284425
    Abstract: A pump for dispensing accurately measured amounts of fluid has a one way check valve in the flow path on the upstream side of a pump chamber and a one way check valve in the flow path at the downstream side of the pump chamber which is of variable internal volume. A flow passage provides fluid communication from the upstream check valve to the pump chamber and enters the pump chamber by a centrally located opening that is surrounded by a valve seat. One wall of the pump chamber is a flexible and elastic diaphragm that is attached to the plunger portion of a solenoid actuator. The plunger and diaphragm are biased by a spring acting upon the plunger such that, in the absence of excitation of the solenoid coil, the diaphragm is biased against a valve seat, preventing flow through the pump.
    Type: Grant
    Filed: November 18, 1992
    Date of Patent: February 8, 1994
    Assignee: The Lee Company
    Inventors: Ludwig K. Holtermann, Jodie D. Haupt, Samuel R. Hanford
  • Patent number: 4958661
    Abstract: A check valve that allows flow in one direction only and is suitable for controlling corrosive, chemically active or sensitive fluids comprises a body formed of a suitably inert substance defining inlet and outlet flow passages with a central chamber between the flow passages and an elastomeric disc traversing the central chamber. Centrally located disc stops bias the disc against an annular valve seat comprising a ridge surrounding the flow path and the sealing engagement of the disc and the valve seat prevents flow through the valve. An increase of the pressure differential across the disc sufficient to overcome the resilience of the disc causes the disc to deform whereby the perimeter of the disc lifts off the valve seat and allows flow through the valve. Support stops are provided at the inlet end of the central chamber to prevent the disc from being forced into the inlet flow passage upon exposure to a high back pressure differential.
    Type: Grant
    Filed: August 8, 1989
    Date of Patent: September 25, 1990
    Assignee: The Lee Company
    Inventors: Ludwig K. Holtermann, Leighton Lee, II
  • Patent number: 4944487
    Abstract: A bidirectional diaphragm valve is presented in which the flat, disk shaped diaphragm formed of elastomeric material is biased against the valve seat by means of a plunger which is not attached to the diaphragm. The diaphragm is clamped between the valve body and a bonnet member providing compression and confinement of the perimeter of the diaphragm, resulting in radial compression of the diaphragm which is expressed inwardly as the expansion and buckling of the central portion of the diaphragm whereby the valve opens passively in response to pressure from the flow medium when the plunger is retracted. The preferred embodiment of the valve is of miniature size and compact configuration adapted for use in multi-valve banks and all parts having wetted surfaces are formed of materials of suitable chemical inertness compatible with the fluid media.
    Type: Grant
    Filed: May 8, 1989
    Date of Patent: July 31, 1990
    Assignee: Lee Company
    Inventor: Ludwig K. Holtermann
  • Patent number: 4492360
    Abstract: A piezoelectric valve with a cantilevered control arm assembly, comprising a piezoelectric valve operating arm and a contiguous limit arm for limiting the opening deflection of the valve operating arm.
    Type: Grant
    Filed: June 7, 1982
    Date of Patent: January 8, 1985
    Assignee: The Lee Company
    Inventors: Leighton Lee, II, Gerald W. O'Dell, Ludwig K. Holtermann
  • Patent number: 4198859
    Abstract: A heat flow monitoring system comprising a heat flow sensor and a meter which is powered by the current from the sensor. The sensor includes a multiplicity of thermoelectric elements in series, mounted to have a hot side and a cool side, such that heat flux in either direction will create an emf sufficient to drive the meter and indicate heat flux values in terms of BTU/ft..sup.2 -hr. and/or watts/cm.sup.2. The meter circuit may include resistances for adjustment to different ranges of heat flux values.
    Type: Grant
    Filed: November 9, 1978
    Date of Patent: April 22, 1980
    Inventor: Ludwig K. Holtermann
  • Patent number: 4102196
    Abstract: A non-contact sensor for observing, recording or responding to the temperature of a hot moving or stationary slender target, such as a wire, wherein a plurality of sensor units, each including a multiplicity of thermocouples, are mounted in arcuate formation within a cylindrical housing and connected in series, the housing being radially slotted so that the target can be introduced laterally and guided on a path along the axis of the housing, the end terminals of the sensor units being adapted for direct attachment to indicating, recording or actuating devices, without signal amplification.
    Type: Grant
    Filed: April 8, 1977
    Date of Patent: July 25, 1978
    Inventor: Ludwig K. Holtermann