Patents Assigned to Vakuum Vulk Holdings Limited
  • Patent number: 4234369
    Abstract: For use in repairing or retreading tires, particularly large tires for earth-moving equipment and the like, the portion to be repaired or retreaded is covered and surrounded by a flexible enclosure attached to the tire in gas-sealing relationship by an adhesive. The adhesive will remain effective even at the temperatures necessary for vulcanization. The enclosure has a gas connection so that it can be evacuated or pressurized to remove air and gas occlusions. A gasket can be used in conjuction with the adhesive.
    Type: Grant
    Filed: May 11, 1978
    Date of Patent: November 18, 1980
    Assignee: Vakuum Vulk Holdings Limited
    Inventor: Wilhelm Schelkmann
  • Patent number: 4151027
    Abstract: The invention relates to the retreading of rubber tires wherein a prevulcanized tread is applied to a tire carcass with an interposed vulcanizable bonding layer. The tread and at least the adjacent part of the carcass are enclosed within a close fitting flexible envelope and the resulting blank is subjected to a pressure- and heat-treatment in an autoclave to bond the tread to the carcass. The invention resides in the construction and use of an envelope which is associated with an adjacent reservoir within the autoclave, preferably between the envelope and tire, for the accumulation of possible gaseous inclusions between the inside of the envelope and the blank.
    Type: Grant
    Filed: August 4, 1977
    Date of Patent: April 24, 1979
    Assignee: Vakuum Vulk Holdings Limited
    Inventors: Wilhelm Schelkmann, Gerda Schelkmann, nee Werner
  • Patent number: 4147642
    Abstract: Renewal of the running surface of a worn pneumatic or solid rubber tire, in which a layer of bonding rubber is applied to the prepared body of the tire and to the interior of a prefabricated precured rubber tread ring has gaseous inclusions between the applied layers led away and the assembly prepared in this way is heated in an autoclave for vulcanizing the layer of bonding rubber. The tread ring directly before applying it to the body is stretched very hard in a simple stretching mechanism so that when the tread ring is removed from the stretching mechanism a free stretch of about three to four percent remains temporarily. This allows the freed but stretched tread ring to be slipped over the body without further auxiliary means retaining the ring stretched and the ring to be arranged in exact correlation with the circumference of the body. The free stretch rapidly and continuously reduces to about one percent permanent stretch.
    Type: Grant
    Filed: May 27, 1977
    Date of Patent: April 3, 1979
    Assignee: Vakuum Vulk Holding Limited
    Inventor: Wilhelm Schelkmann
  • Patent number: 4093481
    Abstract: A method for repairing or retreading a vehicle tire comprising the steps of filling a repair region with vulcanisable rubber, covering the repair region with a flexible cover attached around its edges to the tire with an adhesive, piercing the cover with a suction needle at points where air or other gases have accumulated, sealing of the openings made by the needle, and heating the repair region to vulcanize the repair rubber.
    Type: Grant
    Filed: January 28, 1976
    Date of Patent: June 6, 1978
    Assignee: Vakuum Vulk Holdings Limited
    Inventor: Wilhelm Schelkmann