Patents Assigned to Calvert Manufacturing, Inc.
  • Patent number: 5967208
    Abstract: An improved apparatus and method for use in the rotary cutting of wood veneer is disclosed. The improved apparatus and method are preferably employed in connection with a conventional lathe having a pressure bar. Such a lathe is of the type that is used to produce wood veneer from a workpiece of wood, such as a log. The improvement is characterized as maintaining a preselected pressure of the pressure bar against the wood, and subsequently adjusting the preselected pressure bar position by using means for doing so, thereby producing wood veneer of uniform thickness and surface quality, independent of variations in wood density and wood hardness, such variations resulting from natural growth conditions and temperature of the wood.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: October 19, 1999
    Assignee: Calvert Manufacturing, Inc.
    Inventor: Harry B. Calvert
  • Patent number: 5385185
    Abstract: In a veneer lathe having a knife mounted to a knife support frame with a backing plate, a roundup control system for a veneer lathe is disclosed that recognizes or detects the production of usable veneer using the body of the knife as a signal source. During initial production of veneer, the lathe produces a trash or roundup veneer that is directed to a chipper through a trashgate. When there begins production of usable veneer, the trashgate is closed and the usable veneer is directed toward production trays or stackers. A sensor or displacement detection device is mounted in the backing plate of the knife support frame lateral the unsupported portion of the knife. As the knife contacts wood, the unsupported span of the knife flexes causing the magnet to move which the sensor detects. The sensor outputs a voltage signal proportional to movement of the knife in magnitude and direction. This voltage signal is relayed to a central processing unit where it is converted into a digital signal.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: January 31, 1995
    Assignee: Calvert Manufacturing, Inc.
    Inventor: Harry Calvert
  • Patent number: 4396049
    Abstract: A backup roll arrangement for peeling veneer from a log in a wood veneer lathe which includes a backup roll rotatably mounted on a carriage driven by a dc motor toward the center of the log during a veneer peeling operation. A control system coordinates the position of the backup roll with the position of a veneer knife blade on a knife carriage as it advances toward the axis of the rotating log to peel veneer. The backup roll is positioned intermediate the ends of the log and is controlled to be fed toward the log axis in coordination with the knife so as to prevent bending or bowing of the log core, particularly during the later stages of the veneer peeling operation. The backup roll assembly has a frame mounted generally above the veneer lathe such that as the backup roll carriage moves downwardly, the axis of rotation of the backup roll moves toward the axis of rotation of the log at a constant small angle from vertical.
    Type: Grant
    Filed: February 5, 1981
    Date of Patent: August 2, 1983
    Assignee: Calvert Manufacturing, Inc.
    Inventors: Harry B. Calvert, Dewell M. Nelson
  • Patent number: 4392519
    Abstract: A veneer lathe having power spindle means for rotating a log on the spindle axis, a knife carriage disposed for movement transversely of said spindle axis, a knife rockably mounted on the carriage for movement laterally of the spindle axis, means for adjusting the pitch of the knife as it is moved toward the spindle axis, and means for correcting the pitch adjustment in accordance with lateral deflecting forces on the knife. A sensing device mounted adjacent the knife utilizes lateral deflection of the knife edge during the veneer peeling operation to generate a signal indicating the direction and amplitude of the deflection. The signal may be applied directly to a suitably calibrated deflection indicator. It may also be amplified and utilized to effect a correction in the pitch adjusting means so as to maintain the lateral forces on the knife in approximate balance, with a slight bias toward the wood.
    Type: Grant
    Filed: February 5, 1981
    Date of Patent: July 12, 1983
    Assignee: Calvert Manufacturing, Inc.
    Inventor: Harry B. Calvert