Patents Assigned to Coventry University
  • Patent number: 5866870
    Abstract: An arc augmented laser welding apparatus has a welding head (10) which comprises a housing (14) a focusing system in the housing for focusing a laser beam through a laser opening in the housing onto a workpiece and a plasma torch nozzle (28) through which a plasma arc is established between an electrode (22) and the workpiece. A first power source (44) applies a high voltage across the electrode and nozzle to strike a pilot arc which is then sustained by power from a second source (42). A third power source (40) applies a high amperage signal to strike the main plasma arc between the electrode and the workpiece. The nozzle has a tip (33) which is adapted to constrict the plasma arc and restrict its impingement on the workpiece. The nozzle and the focusing system are arranged to cause the focused laser beam and the constricted plasma arc to impinge on the workpiece at predetermined relative positions which may coincide or may be slightly spaced apart.
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: February 2, 1999
    Assignee: Coventry University
    Inventor: Robert Philip Walduck
  • Patent number: 5560326
    Abstract: An internal combustion engine comprises one or more pairs of first and second cylinders, the first cylinder having a larger swept volume than the second cylinder and respective first and second pistons reciprocable in the cylinders. The second piston has a drive stem and divides the second cylinder into a first volume containing the drive stem of the second piston and a second volume between the two pistons. An air inlet and an exhaust outlet are provided for the first cylinder. A common combustion space is formed between the pistons when the pistons are substantially at their inner dead center positions, the combustion space comprising the second volume. A transfer means enables gas flow between the first volume and the combustion space towards the end of the compression stroke while an inhibiting means inhibits the movement of fuel/air mixture from the first volume into the second volume until towards the end of the compression stroke of the second piston.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: October 1, 1996
    Assignee: Coventry University
    Inventor: Dan Merritt
  • Patent number: 5406912
    Abstract: An internal combustion engine has at least one set of first and second cylinders (12,14), the first cylinder (12) having a larger swept volume than the second cylinder (14), and respective first and second pistons (16,18) movable in the cylinders. The pistons are coupled together such that they are movable in the cylinders in a cyclic manner at the same frequency. An air inlet (24) and an exhaust outlet open into the first cylinder and a fuel injector (34) provides fuel to the second cylinder. A combustion space (20) is also provided which communicates with both cylinders during at least a portion of the expansion stroke. The second piston has a crown (35) and a body portion (19), with the crown being spaced from and connected to the body portion and having an edge (37) which is relatively small in the axial direction compared to the distance between the crown and the body portion in the axial direction.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: April 18, 1995
    Assignee: Coventry University
    Inventor: Dan Merritt
  • Patent number: 5398653
    Abstract: An internal combustion engine has first and second cylinders (12, 14), the first cylinder (12) having a larger swept volume than the second cylinder (14) and the second cylinder being formed in the crown of the first cylinder. First and second pistons (16, 18) are reciprocable respectively in the first and second cylinders (12, 14), the second piston (18) being formed as a protrusion on the crown of the first piston (16). The first cylinder has an air inlet (25) and an exhaust outlet (27) whilst a first fuel source (34) provides fuel to the second cylinder (14). The second piston has a crown (35) which is spaced from and connected to the crown (36) of the first piston and which has an edge (37) which is relatively thin in the axial direction compared to the spacing of the first piston crown from the second piston crown. This defines a combustion space (20) between the piston crowns and a side wall (14a) of the second cylinder (14) when the pistons are substantially at the inner dead center position.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: March 21, 1995
    Assignee: Coventry University
    Inventor: Dan Merritt