Patents by Inventor Menahem Lehr

Menahem Lehr 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: 5014793
    Abstract: A portable electric power tool having a DC motor for driving tool bit is controlled according to speed and torque by employing a zero displacement switch means which is coupled to the tool and operative to provide an output voltage porportional to the pressure applied to the switch means via the hand of the user. The zero displacement switch interfaces with a piezoresistive array which produces a voltage output proportional to the pressure applied to the zero displacement switch. The voltage output of the array is applied to control circuit means which are coupled to the motor and which controls the speed of the motor according to the pressure applied to the switch. There is further included motor control circuitry which operates to monitor the current through the DC motor to control the speed of the motor according to the torque imparted upon the tool bit being accommodated by the portable electric tool.
    Type: Grant
    Filed: April 10, 1989
    Date of Patent: May 14, 1991
    Assignee: Measurement Specialties, Inc.
    Inventors: Damon Germanton, Menahem Lehr