Patents by Inventor Cvetan Petroff

Cvetan Petroff 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: 5009040
    Abstract: A blade sharpener having a sharpening mechanism which functions to sharpen a blade engaging that mechanism and being moved longitudinally relative thereto. The sharpener also includes sharpening defeating means which, when operative, at least inhibits and possibly prevents sharpening of a blade by the sharpening mechanism when that blade is moved longitudinally through the sharpener in one direction. The defeating means is responsive to blade movement so as to adopt an operative condition when the blade is moved in the aforementioned one direction, and to adopt an inoperative condition when the blade is moved through the sharpener in the opposite direction. The defeating means includes a blade engaging member such as a roller, and in the operative condition that roller engages and presses against the cutting edge of the blade so as to impose a force on the blade which acts counter to the force causing the blade to engage the sharpening mechanism.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: April 23, 1991
    Assignee: McPherson's Limited
    Inventor: Cvetan Petroff
  • Patent number: 4862590
    Abstract: A retractable blade knife having a self-sharpening facility which can be selectively rendered inoperable. The sharpener is spring biased in an upward direction so as to be urged into engagement with the cutting edge of a knife blade, and manually operable release means is provided to permit the sharpener to be held in an inoperable position. An assembly of which the sharpener forms part also functions as stop means which positively prevents movement of the knife blade into its extended position. Such extension is possible only upon operation of the release means, but that is only necessary during initial outward movement of the knife blade. The sharpener is arranged to sharpen the cutting edge of the blade up to the tip of the blade. Positive locking means is provided to prevent inward movement of the blade when working under load in the extended position.
    Type: Grant
    Filed: November 10, 1987
    Date of Patent: September 5, 1989
    Assignee: McPherson's Limited
    Inventors: Frank Winyard, Gordon Bremner, Cvetan Petroff
  • Patent number: 4825544
    Abstract: A scissors sharpener including a pair of elongate sharpening elements relatively arranged so as to define a vee shaped sharpening recess between them. Each sharpening element forms a respective one of two sides of the recess and each side has a longitudinal extent which is no less than the length of the scissor cutting edges to be sharpened. At least one of the sharpening elements is mounted so as to be movable laterally away from the other element, and resilient means bears against the movable element so as to resist the aforementioned movement. The sharpening elements overlie a base plate and an extension of that plate forms a platform against which the handle portion of scissors can rest during the sharpening operation. In use, scissors are located on the sharpener with the closed blades over the recess and the cutting edges extending generally in the longitudinal direction of the recess sides.
    Type: Grant
    Filed: March 29, 1988
    Date of Patent: May 2, 1989
    Assignee: McPherson's Limited
    Inventor: Cvetan Petroff
  • Patent number: 4669337
    Abstract: A blade sharpener having an access opening through which a blade is moved to be sharpened and including a sharpening device which engages with and sharpens the blade cutting edge and a reaction member which engages with and applies downward pressure to the blade back edge. The reaction member has an upper portion which is pivotally mounted adjacent an upper extremity of the access opening and at a location forward of the sharpening device. A lower portion of the reaction member is engageable with a knife blade. The sharpening device is mounted adjacent the lower extremity of the access opening. A spring urges the reaction member into a rest position at which the lower portion of that member is located forward of the sharpening device and rearward of the pivotal mounting of the reaction member.
    Type: Grant
    Filed: June 11, 1986
    Date of Patent: June 2, 1987
    Assignee: McPherson's Limited
    Inventor: Cvetan Petroff
  • Patent number: D295132
    Type: Grant
    Filed: November 6, 1985
    Date of Patent: April 12, 1988
    Assignee: McPherson's Limited
    Inventors: Alfred Blochlinger, Christopher Collins, Cvetan Petroff, David Watson
  • Patent number: D296498
    Type: Grant
    Filed: November 6, 1985
    Date of Patent: July 5, 1988
    Assignee: McPherson's Limited
    Inventors: Christopher Collins, Wallace Tench, Cvetan Petroff, Alfred Blochlinger
  • Patent number: D298399
    Type: Grant
    Filed: November 6, 1985
    Date of Patent: November 8, 1988
    Assignee: McPherson's Limited
    Inventors: Alfred Blochlinger, Christopher Collins, Wallace Tench, Cvetan Petroff
  • Patent number: D303731
    Type: Grant
    Filed: May 12, 1986
    Date of Patent: October 3, 1989
    Assignee: McPherson's Limited
    Inventors: Alfred Blochlinger, Christopher Collins, Cvetan Petroff, Wallace Tench
  • Patent number: D303921
    Type: Grant
    Filed: May 12, 1986
    Date of Patent: October 10, 1989
    Assignee: McPherson's Limited
    Inventors: Alfred Blochlinger, Christopher Collins, Cvetan Petroff, Wallace Tench
  • Patent number: D305096
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: December 19, 1989
    Assignee: McPherson's Limited
    Inventors: Wallace Tench, Christopher Collins, Cvetan Petroff, Gordon Bremmer