Patents Assigned to Protol A.G.
  • Helically wound lock seam tube
    Patent number: 6561228
    Abstract: In a method for producing helically wound lock-seam tubing, a metal strip is fed to a forming head in which the tubing is formed. In order to frictionally interlock this lock seam, a flexible string is inserted into and compressed in the lock seam during manufacture.
    Type: Grant
    Filed: April 13, 2000
    Date of Patent: May 13, 2003
    Assignee: Protol A.G.
    Inventor: Kenneth Lennartsson
  • Helically wound lock-seam tube
    Patent number: 6513553
    Abstract: In a method for producing helically wound lock-seam tubing, a metal strip is fed to a forming head in which the tubing is formed. In order to prevent lock-seam slip, a clinching roller device form interlocking spaced deformations on the lock-seam. An apparatus for such production comprises a clinching roller provided with a recess for forming the deformations against a counter roller.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: February 4, 2003
    Assignee: Protol A.G.
    Inventor: Kenneth Lennartsson
  • Helically wound lock-seam tube
    Patent number: 6085801
    Abstract: In a method for producing helically wound lock-seam tubing, a metal strip is fed to a forming head in which the tubing is formed. In order to prevent lock-seam slip, a clinching roller device form interlocking spaced deformations on the lock-seam. An apparatus for such production comprises a clinching roller provided with a recess for forming the deformations against a counter roller.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: July 11, 2000
    Assignee: Protol A.G.
    Inventor: Kenneth Lennartsson
  • Method and apparatus for producing helically wound lock-seam tubing
    Patent number: 6003220
    Abstract: In a method for producing helically wound lock-seam tubing, a metal strip is fed to a forming head in which the tubing is formed. In order to prevent lock-seam slip, a clinching roller device form interlocking spaced deformations on the lock-seam. An apparatus for such production comprises a clinching roller provided with a recess for forming the deformations against a counter roller.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: December 21, 1999
    Assignee: Protol A. G.
    Inventor: Kenneth Lennartsson
  • In and relating to machines for forming helically wound lock-seam tubing having multiple wall thickness
    Patent number: 5737832
    Abstract: This invention pertains to a machine for forming helical lock-seam tubing. The machine includes rollers for forming flanges on edges of laterally staggered overlapped strips, a forming head for forming the strips into a helical configuration, rollers for clinching the flanges into locking engagement, reels for supplying the strips, and structure for guiding the strips from the reels to the forming rollers.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: April 14, 1998
    Assignee: Protol A.G.
    Inventor: Antony John Bubb
  • Method and apparatus for producing helically wound lock-seam tubing
    Patent number: 5720095
    Abstract: In a method for producing helically wound lock-seam tubing, a metal strip is fed to a forming heed in which the tubing is formed. In order to prevent lock-seam slip, a clinching roller device forms interlocking spaced deformations on the lock-seam. An apparatus for such production comprises a clinching roller provided with a recess for forming the deformations against a counter roller.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: February 24, 1998
    Assignee: Protol A.G.
    Inventor: Kenneth Lennartsson
  • Helically wound lock-seam tube
    Patent number: D376193
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: December 3, 1996
    Assignee: Protol A.G.
    Inventor: Kenneth Lennartsson
  • Clinching roller
    Patent number: D379358
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: May 20, 1997
    Assignee: Protol A.G.
    Inventor: Kenneth Lennartsson