Patents Assigned to Lewecke Maschinenbau GmbH
  • Patent number: 4703966
    Abstract: A vacuum lifting arrangement for flat workpieces, such as wooden boards, wooden beams and the like, includes a vertically and horizontally movable housing bounding a suction chamber having a downwardly open suction side. A valve insert is accommodated in the suction chamber and is preferably removably mounted on the housing. A closing plate is hingedly mounted on the housing for pivoting into an out of a closing position in which it sealingly covers the downwardly open suction side of the suction chamber and the valve insert. An elastic sealing element in the form of a foamed mat having suction apertures is mounted on the closing plate, and is operative for sealingly contacting the workpieces to be lifted.
    Type: Grant
    Filed: March 4, 1987
    Date of Patent: November 3, 1987
    Assignee: Lewecke Maschinenbau GmbH
    Inventors: Ernst Lewecke, Manfred Riesenberg
  • Patent number: 4693458
    Abstract: An arrangement for clamping a lumber element during its processing especially in a sawing installation includes at least two spaced abutment members having abutment surfaces for the lumber element. A substantially vertically extending suction plate is situated between the abutment elements and includes an upright contact plane. The suction plate is movable transversely to its contact plane and has a plurality of suction openings capable of exerting suction effect on the lumber element which is juxtaposed with the contact plane. Respective contactless sensors sense the presence of the lumber element at the respective suction openings and generate corresponding indication signals. The suction effect of the suction openings is controlled by an electrical switching and control device in dependence on the indication signals.
    Type: Grant
    Filed: November 24, 1986
    Date of Patent: September 15, 1987
    Assignee: Lewecke Maschinenbau GmbH
    Inventors: Ernst Lewecke, Manfred Riesenberg
  • Patent number: 4674785
    Abstract: A vacuum lifting arrangement for flat workpieces, such as lumber boards, lumber planks and the like includes a vertically and horizontally displaceable housing which forms a vacuum chamber, and an elastic sealing element arranged at the underside of the housing for conformingly contacting the workpiece and constituted either by a foamed material mat with suction apertures or by individual suction cups. The vacuum chamber is constructed as a vacuum accumulator and a valve plate is interposed between the housing and the sealing element. The interior of the valve plate is subdivided into a plurality of individual vacuum compartments each equipped with a valve and is connected with the vacuum chamber by a suction opening which can be selectively opened and closed. Each of the vacuum accumulator and the valve plate is provided with its own admission opening which communicates with the ambient atmosphere, such openings being openable and closable in unison.
    Type: Grant
    Filed: March 6, 1986
    Date of Patent: June 23, 1987
    Assignee: Lewecke Maschinenbau GmbH
    Inventor: Manfred Riesenberg